5166 5170.output

* GB785573 (A)

Description: GB785573 (A)

No title available

Description of GB785573 (A)

PATENT SPECIFICATION 7859573 Date of Application and filing Complete Specification: Nov 14, 1955. No 32462/55. \\ 5/ D Application made in Germany on Feb 8, 1955. \\\'> 9 </> Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 97 ( 1), B 7 C. International Classification:-GO 2 b. COMPLETE SPECIFICATION Improvements in or relating to Rapid Taking Lenses with Variable Focal Length for Photography or Cinematography I, MARGARETE CAMILLA SCHNEIDER, of German nationality, sole proprietress of the firm Jos Schneider & Co, Optis'che Werke, of Kreuznach (Rhineland), Germany, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:Taking lenses of variable focal length are known They consist normally of a multicomponent main objective facing the image plane and a system of lenses preceding the multi-component main objective and composed of three members, of which the one with the longer focal length and the one facing the multi-component main objectivedhave a positive refractive power, and these two components enclose a negative member preferably consisting of two lenses of opposite refractive powers cemented together, which can be displaced in the direction of the optical axis, in order to change the focal length. Such systems which have become known hitherto with a relative aperture of 1: 2 8 have a range of focal lengths of the ratio of about 1: 3 One of the factors determining the focal length is the displaceable negative member In order to maintain the back lens/image distance constant the front positive member of the supplementary system must

also be displaced The greatest length of the total system is obtained for a medium focal length over the entire setting range, while for a smaller and larger focal lengths the front member of the supplementary system must move towards the rear members under the control of a cam. It is the aim of the invention to increase the range of focal lengths of such systems, while the comparatively high relative aperture of 1: 2 8 is retained, in order to achieve a range of focal lengths of the ratio of about 1:4 This is achieved by making the main objective of four air-spaced lenses, which may be described as a modified Taylor-triplet while the positive member of the supplementary system, displaceable and facing the longer conjugate, consists of two members separated by an air space and the fixed member facing the multi-component main objective must consist of a single lens, and also the negative member between the said positive members, which is axially displaceable and consists of two lenses of opposite refractive powers cemented together, is curved in such a way that its shape is substantially plano-concave, or that of a negative meniscus. In order to increase the range of focal lengths, or to improve the quality of the image within the setting range which has been achieved so far, it has been found to be advantageous to constitute the displaceable positive member of the supplementary system of two individual components, each of which has preferably the shape of a positive meniscus with external surfaces convex towards the longer conjugate of which the forward member is a single lens, and the following member consists of two lenses of opposite refractive powers cemented together so that the negative lens faces with its concave surface the following displaceable negative member. By means of this design scheme the aberrations could be substantially reduced in a system designed according to the invention Due to the arrangement of the intermediate displaceable negative member of the supplementary

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* GB785574 (A)

Description: GB785574 (A) ? 1957-10-30

Pharmaceutical compositions containing tetracycline antibiotics

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION 785,574 Date of Application and filing Complete Specification Dec 13, 1955 No 35723/55. Application made in United States of America on March 29, 1955. Complete Specification Published Oct 30, 1957. Index at Acceptance: -Class 81 ( 1), B 2 (G: L: N: R: S: T). International Classification:A Ak. COMPLETE SPECIFICATION Pharmaceutical Co Lunpositions co ntain Tetracycline Antibiotics We, CHAS PFIZER & Co, INC, a Corporation organized and existing under) the Laws of the State of Delaware, United States of America, located at 11, Bartlett Street, Brooklyn 6, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention is concerned with certain pharmaceutical compositions In particular, it is concerned with compositions containing one of a group of antibiotics together with certain vitamins The antibiotics useful in the present compositions are oxytetracycline, chlortetracycline, and tetracycline The vitamins which are of particular value in the present compositions are the water soluble vitamins, that is, the B vitamins, ascorbic acid, vitamin K, and are hereinafter specified. The broad-spectrum antibiotics, chlortetracycline, oxytetracycline, and tetracycline have very great value in the treatment of a variety

of infectious diseases These compounds are, however, occasionally accompanied during their administration, by certain undesirable side effects Some of these side effects may be due to changes brought about in the intestinal flora This may lead to difficulty in recuperating fully and most rapidly from the effects of various infectious diseases, despite the fact that the infecting microorganism is eradicated by the antibiotic. It has now been found that compositions containing one of the antibiotics indicated above, that is oxytetracycline, chlortetracycline, or tetracycline together with the water soluble vitamins, particularly the B vitamins, are very effective in the treatment of infectious diseases Use of these compositions leads to the greatest rapidity in complete recovery from the effects of the disease This is true despite the fact that the side effects to which reference is made above, are often not encountered for several days or more after the administration of the broad-spectrum antibiotics listed above It has been found that lPrice 3 MQ 45 Ad the compositions of the present invention are particularly effective in bringing about com 50 plete and uncomplicated recovery from debilitating infectious diseases The effect upon these diseases of the present compositions is an effect which could not normally be anticipated from the known antibacterial 55 activity of the antibiotics and the known nutritional value of the vitamins. The compositions of the present invention may be prepared in a variety of forms including capsules, tablets, suspenions and other 60 pharmaceutical forms A variety of pharmaceutically-acceptable carriers may be utilized in the preparation of these compositions These carriers serve to present the compositions in easily administered, con 65 venient form for therapy of the various infectious diseases with which the broad-spectrum antibiotics may be treated In general, from about 50 to about 500 milligrams of the antibiotic is used per unit dosage form 70 The antibiotic in the present compositions may be utilized in the form of the amphoteric compound or in the form of its hydrochloride or other acceptable (i e non-toxic) salt The a-6 anhydro and 4-desdimethyl amino 75 derivatives of the antibiotics which are microbiologically active may also be utilized in the preparation of the present compositions However, the amphoteric antibiotic compounds are particularly suited for the preparation of these 80 materials, especially when a suspension of the antibiotic is to be prepared Since certain of the vitamins utilized in the present compositions have a low order of solubility, it is advisable that these compounds be finely divided, 85 as must also the antibiotic, if a suspension of these materials is to be prepared If a suspension form of the compositions is to be utilized, it is desirable to include suspending

and wetting agents in the composition to facilitate the 90 formation of a uniform composition so that administration of the material will be accompanied by a uniform dosage of the material when a given volume is measured out. At last the two water-soluble vitamins not 95 all in the same group or class are employed in 785,574 the present compositions, which are selected from the groups or classes consisting of ascorbic acid, or a salt of ascorbic acid, for instance, the sodium or calcium salt, or a mixture of these; thiamin, generally utilized in the form of the hydrochloride, although the mono nitrate may also be used; riboflavin; niacin or niacinamide; pyridoxine, generally utilized as the hydrochloride; pantothenic acid, normally utilized as the calcium salt; folic acid; vitamin K, which may be in the form of the natural material or various synthetic analogs; and vitamin Bl,, which is available as the crystalline material or in the form of various partially purified concentrates If an orally administratable, suspension form of the compositions is to be prepared, various fiavoring materials may be included, as well as coloring materials Monosodium glutamate is useful in imparting a desirable flavor to the composition, and sweetening agents such as sucrose, sucaryl, and other similar materials may be added to the preparations As suspending agents one may utilize esters or ethers of cellulose, for instance, carboxymethyl cellulose A wetting agent is often desirable in order to obtain a uniform suspension which is readily wetted upon the addition of the liquid diluent, preferably water Wetting agents which are useful are fatty acid esters of poelyoxyrnethylene derivatives of anhydro sugars such as Tweens (Registered Trade Mark). If tablets are to be prepared from the present compositions, various agents which are useful as binders, such as polyvinylpyrrolidone and various natural or synthetic gums, together with starches and such lubricants as magnesium stearate, may be prepared in a suitable composition before the formation of the tablets by conventional manufacturing procedures. Ascorbic acid may be utilized in the present compositions to the extent of from about 30 to about 100 milligrams per unit dosage form. This material may be in the form of the acid or partly or wholly as a salt such as the sodium salt In the aqueous suspensions, mixtures of ascorbic acid and sodium ascorbate are particularly useful Thiamin is utilized to the extent of about 1 to about 3 milligrams per unit dosage of the present compositions Riboflavin is utilized to the extent of from about I to about 3 milligrams per unit dosage form. Niacin, or preferably niacinamide, is utilized to the extent of from about 2 to about 20 milligrams per unit dosage form Pyridoxine is utilized to the extent of from about 0 1 to 0 5 milligrams per unit

dosage form Pantothenic acid, preferably as the calcium salt, is utilized to the extent of from about 1 to about 10 milligrams per unit dosage form Folic acid is utilized to the extent of from about 0 1 to 2 milligrams per unit dosage form Vitamin K is utilized to the extent of from about 0 1 to about 1 milligram per unit dosage form. Vitamin B 12 is utilized to the extent of from about 0 1 microgram to about 20 micrograms per unit dosage form. It should be noted that not only are the compositions of the present invention quite compatible, that is, the components of the compositions do not exert an adverse effect on one another, but, in addition, the compositions exert certain effects that could not be predicted from the known properties of their components Thus, side effects which sometimes occur are often averted and recurrence of the infection is frequently avoided The patients resistance and ability to ward off the damaging effects of the infection are generally increased. Toleration of tie medication is also often enhanced and convalescence may be decreased in time. The following examples are given by way of illustration and are not to be considered as the sole embodiments of this invention. EXAMPLE I A blendor commonly used for the preparation of pharmaceutical compositions was charged with 1700 grams of sucrose The material was blended and to this was added 90 the flavoring agent, such as synthetic raspberry flavor Three hundred grams of sucrose was placed in a mixer To this was added 0 6 grams of Tween (Registered Trade Mark) 80. The material was thoroughly mixed for a 95 period of 20 minutes To this blended mixture was added 5 grams of sodium sucaryl, 60 grams of carboxymethyl cellulose No 70 medium viscosity, and 2 grams of monosodium glutamate The material was mixed for an 100 additional 20 minutes and then it was passed through a mill to form a very finely divided powder This mixture was then thoroughly mixed with the source containing the flavoring agents prepared above The combined 105 mixture was passed through a mill so that it was thoroughly blended and pulverized. To 100 grams of sucrose in a mixer was added 1 7 grams of riboflavin The mixture was thoroughly agitated to obtain a uniform 110 product To this was added 160 grams of anhydrous amphoteric tetracycline, 2 7 grams of ascorbic acid, 55 6 grams of sodium ascorbate, 2 0 grams of thiamin hydrochloride, 15.0 grams of niacinamide, 0 3 grams of 115 pyridoxine hydrochloride, 4 5 grams of calcium pantothenate, 0 27 grams of folic acid, 0.3 grams of vitamin K, 0 9 grams of a triturate of vitamin B 12 in mannitol containing an activity equivalent to 0 1 %

by weight The 120 composition was thoroughly mixed until homogeneous throughout It was then passed through a micropulverizer to obtain an extremely finely divided powder This was then blended with the sucrose, sucaryl, car 125 boxymethyl cellulose, monosodium glutamate mixture prepared as described above 23 3 gram portions of this material were placed in 2 ounce bottles. vitamin D (one million USP units in the form of irradiated yeast powder as supplied by Standard Brands Corporation), 5 56 grams of niacinamide, 860 grams of dibasic calcium phosphate, 10 grams of ferric phosphate and 4785 grams of a chocolate powder (containing a mixture of sugar and chocolate together with certain gums which forms a relatively stable suspension-Banker's " Four-in-One " chocolate powder) The mixture was thoroughly blended and packaged in small wide-mouth bottles One teaspoon of this preparation contained approximately 100 milligrams of amphoteric oxytetracycline The powder was readily suspended in water, milk or any other beverages and constituted an easily administered therapeutic agent for treatment df various infections diseases. It was found that upon filling the bottle with water a suspension was readily prepared which was highly palatable, uniform throughout, and easily resuspended on standing The S mixture proved highly effectitve in obtaining rapid remission of a variety of infectious diseases due to organisms susceptible to tetracycline It was found that, in addition, the material brought about a rapid rehabilitation of the patient, to a degree not commonly encountered when tetracycline alone was utilized for treatment of these individuals. EXAMPLE II A tetracycline-vitamin composition was prepared by thoroughly blending with the antibiotic a mixture of vitamins, corn oil, and an inert, edible microcrystalline wax The detailed method follows: 41 g of edible wax was melted at 600 C This material was added to 273 g of USP corn oil which was agitated strongly during the addition of the melted wax The mixture was thoroughly mixed and cooled to 300 C While it was being agitated, the following materials were added in the indicated order: 278 g of amphoteric tetracycline 93 g of sodium ascorbate 4 g of a mixture of essential oil flavoring agents 0 5 g of vitamin K USP 0.4 g of folic acid USP 3.4 g of thiamin mononitrate 2.9 g of riboflavin 0.5 g of pyridoxine hydrochloride 0 5 g of vitamin B 1, concentrate having a potency of 3000 micrograms per gram 7.5 g of calcium pantothenate USP g of lecithin 25 g of nicotinamide The mixture was thoroughly agitated until a complete uniform suspension was obtained. The mixture was then packed in gelatin capsules utilizing sufficient material for each capsule so that each contained 250 milligrams of the

antibiotic. EXAMPLE III The preparation of the above example was repeated utilizing in place of tetracycline, oxytetracycline amphoteric This material also was prepared in capsules of two different sizes, one containing 100 milligrams of oxytetracycline and the second containing 250 milligrams of oxytetracycline. EXAMPLE IV A mixture was prepared containing 227 8 grams of amphoteric oxytetracycline, 6 09 grams of dry vitamin A acetate in gelatin (in the forms of fine beadlets having a total activity of two million units), 3 0 grams of thiamin mononitrate, 1 15 grams of riboflavin, 99.75 grams of ascorbic acid, 1 38 grams of EXAMPLE V A hard candy base was prepared by combining a concentrated solution of sucrose in water and corn sugar The mixture was melted in a jacketed kettle and heated to about 85 2400 F It was then passed through a coil at about 2900 to 3000 F to thoroughly cook the mixture The mixture was then concentrated under vacuum to dehydrate the material At this stage, a mixture wars 90 obtained containing approximately 60 % sucrose and 40 % corn syrup solids and a very limited percentage of water (less than 1 %). Ten pounds of this candy base mix was placed in a mixing kettle and to this was added 18 95 milliliters of oil and orange and 3 grams of orange paste color The mixture was stirred thoroughly and cooled to 1180 C and 25 14 grams of Terramycin (Registered Trade Mark) amphoteric (amphoteric oxytetracycline) was 100 added with thorough mixing This was followed by 0 6 grams of a vitamin A dry product assaying about one million units of vitamin A activity per gram There was then added thet following materials: 1 5 grams of 105 thiamin hydrochloride, 2 64 grams of riboflavin, 1512 grams of niacinamide, 43 2 grams of ascorbic acid, 2 7 grams of pantothenyl alcohol, 1 26 grams of pyridoxine, 1 584 grams of vitamin E and 0 00378 grams of vitamin 110 B 12 The mixture was thoroughly blended, cooled and cast in the form of lozenges of such a size that approximately 120 were formed from each pound of the mixture Each tablet contained approximately 18 milligrams of 115 amphoteric Terramycin (Registered Trade Mark), 6000 units of vitamin A, 500 units of vitamin D, 1 25 milligrams of thiamin, 2 milligrams of riboflavin, 12 milligrams of niacinamide, 36 milligrams of ascorbic acid, 2 milli 120 grams of pantothenyl alcohol, 1 milligram of pyridoxine, 1 2 milligrams of vitamin E, and 3 micrograms of vitamin B 12 These candy tablets proved highly effective for administering a composition of the antibiotic and vita 125 mins to young patients. 785,574 EXAMPLE VI

The preparation described in the example directly above was repeated utilizing in place of the amphoteric oxytetracycline an equivalent weight of amphoteric tetracycline This product was also found to be highly effective in the treatment in children of infectious diseases such a throat infections. EXAMPLE VII The preparation described in Example I above was repeated utilizing in place of oxytetracycline an equivalent weight of chlortetracycline The composition thus obtained was proven to be highly effective in combatting infectious diseases, resulting in rapid and thorough rehabilitation of the infected patient. In view of Section 9 Subsection ( 1) of the Patents Act, 1949, attention is directed to


* GB785575 (A)

Description: GB785575 (A) ? 1957-10-30

Compatible image-reproducing system


A high quality text as facsimile in your desired language may be available amongst the following family members:

CH337875 (A) DE1024561 (B) FR1141121 (A) US2759993 (A) CH337875 (A) DE1024561 (B) FR1141121 (A) US2759993 (A) less Translate this text into Tooltip



PATENT SPECIFICATION Date of Application and filing Complete Specification: Dec 13, 1955. No 35782155. Application made in United States of America on Jan 17, 1955. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 40 ( 3), F( 3 B: 5 F). International Classification:-H 04 n. COMPLETE SPECIFICATION Compatible Image-Reproducing System We, HAZELTINE CORPORATION, a corporation organized and existing under the laws of the State of Delaware, United States of America, of 59-25 Little Neck Parkway, Little Neck 162, New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - GENERAL The present invention is directed to compatible image-reproducing systems for colortelevision receivers and, more specifically, to such image-reproducing systems in a compatible-color television receiver of the NTSSC type,utilizing a single-gun type of picture tube employing a switching signal for directing the electron beam onto different 'color phosphors. By compatible image-reproducing system is meant an image-reproducing system capable of reproducing color and monochrome images in response to color and monochrome signals, respectively. In la form of color-television system more completely discussed in many articles in the January, 1954 issue of the PROCEEDINGS OF THE I R E information representative of a scene in color being televised is utilized to develop at the transmitter two substantially simultaneous signals, one of which is primarily representative of the brightness or luminance and the other of which is representative of the chrominance of the televised image The latter signal is a subcarrier wave signal having a mean frequency within the video-frequency pass band and having each of successive cycles thereof modulated in amplitude at different phases by signall components representative of specific 'hues of the televised image The 'composite video-frequency signal comprising the luminance signal and the modulated subcarrier wave or chrominance signal is then employed in a conventional manner to modulate a radio frequency wave signal The signals just described are utilized in an NTSC type of system and, therefore, T Price 3 s -L -,,

l will be referred to hereinafter as NT Sz C type of signals. A receiver in NTSC type of system intercepts the radiated signal and derives the composite video-frequency signal, including the luminance and chrominance signals, therefrom One type of such receiver includes a pair of principal channels for individually translating the luminance and chrominance information for application m an image-reproducing device in such receiver The channel for translating the luminance signal is substantially the ssame as the video-frequency amplifier stage of a conventional monochrome receiver In one type of receiver the channel for translating the chrominance signal includes means for deriving signals representative of the primary colors red, green, and blue and for combining such derived signals with the luminance signal to provide signals which may be utilized in an imiage-reproducing device to effect color reproduction of the televised image. More recently, a one- gun type of image" reproducing device, referred t'o as a focusmask type of device, and circuits for modifying the NTSC type of composite video-frequency signal for use in such device have been described in an article entitled " Processing of the NTSIC Color Signal for One-,Gun Seqential Color Displays " in the January 195 '4 issue of the PROCEEDINGS OF THE I R E at pages 299-3018, inclusive As described in such article, the focus-mask type of picture tube includes repeating groups of parallel strips of different phosphors individually for emitting green, red and blue colors, each group having the sequence green, red, green, blue A grid structure comprising a plurality of conductors which are parallel to each other and to the phosphor strips on the screen has one of such conductors positioned behind each of the phosphor strips for emitting red and blue colors and none behind the strip for emitting green Such grid is energized by a signal synchronized with the modulated subcarrier wave signal so Has to direct the cathoderay beam, intensity-modulated by the brightness and sub'carxier wave signals, onto the proper phosphor strips As described in the I R E. article, an NTSC type of signal may not be applied directly to a picture tube of the type just described if fidelity of color reproduction is to be obtained Prior to application to such picture tube, the luminance signal should be modified ito include a lurninance-correction component and the modulated subcarrier wave signal should be converted into one wave signal of the same mean frequency as the detected chrominance signal, and including only color information representative of red and blue, and into a second harmonic wave signal including information representative of green. The modified luminance signal and fundamental and second harmonic subcarrier wave signals are combined for application to such picture

tube to effect reproduction of the color image. Such modified NTSC type of composite videe-frequency signal is adequate to reproduce a color image in such picture tube when color information is being transmitted and received However, when only monochrome information is being received, or it is desired to reproduce a monochrome image from color signals, the black-and-white image reproduced in this type of picture tube tends to have spurious color patterns having red and blue elements These spurious patterns apparently arise from a heterodyning 'of the high-frequency monochrome signals, particularly those signals in, the range of 3-4 megacycles, with the color-switching operation occurring at approximately 3 6 megacycles Such heterodyning results in low-frequency beat signals of approximately 0- 6 megacycle which appear with high visibility as red and blue patterns These spurious effects have been reduced by including in the luminance channel a filter network having an upper cutoff frequency of approximately 3 megacycles so that effectively no luminance information above 3 megacycles is utilized However, the use of such filter network is detrimental in preventing the reproduction of high-definition monochrome images Though it is desirable to eliminate or minimize such spurious color patterns reproduced in a monochrome image, it is equally important to utilize all of the luminance information 'available in order to obtain the highest quality of reproduction and the maximum degree of compatibility The compatible anage-reproducing system in accordance with the present invention is designed to effect such result. It is, therefore, an object of the present invention to provide a new and improved comnpatible image-reproducing system in which the deficiencies of prior such systems when utilizing an NTSC signal are diminished. It is another object of tthe present invention to provide a new and improved imagereproducing system for a color'television receiver including a single-gun type of picture tube in which the monochrome images reproduced by such system have increased definition 70 It is a still further object of the present invention to provide a new and improved compatible image-reproducing system for a colortelevision receiver including a single-gun type of picture tube, and in which an NTSC type 75 of signal is employed, in which reproduced monochrome images have higher definition than in prior such systems with a minimum of spurious color patterns. In accordance with the present invention, 80 a compatible image-reproducing system comprises a circuit for supplying monochrome or color signals representative, respectively, of televised monochrome or color images and comprises image-reproducing apparatus The 85 image-reproducing apparatus includes a plurality of parallel

color-reprcducing strips, means for developing an electron beam, deflection means for causing the beam to scan a raster on the strips, and color-switching 90 means for cyclically moving the beam across the strips to reproduce a monochrome or color image Spurious color patterns tend to appear in the reproduced monochrome images from signals applied to the apparatus having 95 frequencies in the vicinity of the color-switching frequency The image-reproducing system also comprises a first signal-translating channel coupled between the supply circuit and the beam-developing means for translating a 100 band of the supplied monochrome signals having frequencies below the color-switching frequency for intensity-modulating the beam when monochrome images are being reproduced Finally, the image-reproducing sys 105 tem comprises a second signal-translating channel, including an auxiliary deflection means for developing a field in the path of the electron beam, and coupled to the supply circuit for translating a band of the supplied 110 monochrome signals having frequencies in: the vicinity of the color-switching frequency fox effecting deflection modulation of the beam lengthwise of the strips to provide the highdefinition monochrome information when 115 monochrome images are being reproduced, thereby to minimize the spurious patterns in the reproduced monochrome images. For a better understanding of the present invention, together with other and further ob 120 jects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims. Referring to the drawings: 125 Fig 1 is a schematic diagram of a colortelevision receiver including a compatible image-reproducing system in accordance with the present invention; Fig la is a vector diagram useful in ex 130 7 t 85,5175 and the amplifier 22 will be considered hereinafter with respect to Fig 2 An output circuit of the selector 20 is also coupled through an R-B amplifier 35, having a pass band of 3.0-4 2 megacycles, and the adder circuit 13 70 to the cathode of the image-reproducing apparatus 14. For effecting control of the signal-detecting and color-switching signals iin a manner to be considered more fully hereinafter, the 75 system 12 includes, in cascade in the order named and coupled to an output circuit of the amplifier 19, an automatic-phase-control system 27 and a reference-signal generator 218 The generator 28 can be a conventional 80 sine-wave generator and the system 27 maintains the operation of tlhe generator 2,8 in synchronism and at a specific phase with respect to a reference signal developed at the transmitter, A more detailed description of the sys 85 tem 2,7 will be presented hereinafter when considering the system 12 in detail The output circuit of the generator 28 is coupled through a push-pull amplifier

29 to a colorswitching control grid 14 b in the image-re 90 producing apparatus 14. There are also coupled in cascade in the order named between an output circuit of the axis selector 20 'and an input circuit of the adder circuit 13, la modulator 23 and a 16 6 95 7.8 megacycle filter network 24 The output circuit of the generator 28 is coupled through a second harmonic amplifier 34 and:a phasedelay circuit 32 to an additional input circuit of the axis selector 20 A control circuit in the 100 axis selector 20 for controlling the state of operation thereof is coupled to an output circulit of a colior-killer circuit 36, a component in the system 12 and to be considered more fully hereinafter The output circuit of the 105 generator 28 is 'also coupled through a phasedelay circuit 30 and a third harmonic amplifier 31 to an input 'circuit of the modulator 23 The modulator 23, the filter network 24, and the third harmonic amplifier 31 can be of 110 conventional construction, units of these types being so well known as to require no further description The phase-delay circuits 30 and 32 'are networks for delaying the phase of the signal generated in the generator 28 by appro 115 priate amounts so that the signals applied to the axis selector 20 and the modulator 23, after such phase delays, are in phase with the desired modulation axis of the subcarrier wave signal, 'as will be discussed more fully herein 120 after. There are also coupled in cascade in the order named between an output circuit of the amplifier 19 and an input circuit of the adder circuit 13, an M-Y synchronous detector 25 125 and a 0-0 6 megacycle filter network 2 '6 An input circuit of the synchronous detector 2 '5 is coupled to the oolor-killer circuit 316 to control the state of operation of the detector 25, in a manner to be considered more fully 130 plaining the operation of the image-reproducing system of Fig 1; Fig lb comprises a group of curves useful in explaining the operation of the compatible image-reproducing system of Fig 1; Fig 2 is la more detailed diagram of a portion of the image-reproducing system of Fig. 1, and Fig 3 is a diagram of la modified portion of the image-reproducing system of Fig 1. GENERAL DESCRIPTION OF RECEIVER OF FIG 1 Referring now to Fig 1 of the drawings, there is represented a color-television receiver of the super-heterodyne type suitable for utilizing an NTSC type of color-television signal and, more specifically, a receiver of the type described in the aforementioned I R E article entitled " Processing of the NTSC Color Signal for One-1 Gun Sequential Color Displays " The receiver includes a video-frequency signial source 10 The source 10 can ibe conventional equipment for supplying an NTSIC type of composite video-frequency signal, for example it may include a radio-frequency amplifier having

an input circuit coupled to an antenna 11 an oscillator-modulator, an intermediatefrequency iamplifier, -and a detection system for deriving the video-frequency signal An inage-reproducing system 12, in accordance with the present invention, is coupled to;an output circuit of the unit 10 Though the system 12 will be described fully hereinafter, it will be helpful to described at this time, at least generally, some of the components in the system 12 and their combination The system 12 includes a luminance channel coupled to the aforesaid output circuit of the unit 10 and including, in cascade in the order named, a delay line 15, a luminance-signal amplifier 16, 0-3 megacycle filter network 17 and an adder circuit 13, the output circuit of the latter unit being coupled to the cathode of a single-gun image-reproducing apparatus '14 The delay line 15 is conventional 'and serves to equalize the time of translation of the luminance signal through the units 15, 116, and 17 with that for translation of the chrominance signal through other channels to be considered hereinafter The amplifier 116 is a conventional wide band amplifier The image-reproducing apparatus 14 is 'a single-gun, focusmask type 'of apparatus fully considered in the aforesaid I R E article and will be considered more fully hereinafter. The image-reproducing system 12 also includes, coupled in cascade in the order named between the aforesaid output circuit of the source 10 iand an auxiliary deflection winding 14 d in the apparatus 14, 'an amplifier 19 having a pass band of approximately 3 0-4 2 megacycles, an R-B and G-M axis selector 20 a 3 '0-4 2 megacycle filter network 21, and a deflection-signal amplifier 22 Deetails of the taxis selector 20, the network 21, 785,5175 hereinafter An additional input circuit of the synchronous detector 25 is coupled through a phase-delay circuit 33 to the output circuit of the generator 28 for the purpose of applyilg, from the unit 28 to the detector 25, a locally generated signal which is in phase with the AMI-Y modulation component of the subcarrier wave signal as more fully described in the aforesaid I R E article. A synchronizing-signal separator 37 is also coupled to an output circuit of the video-frequency signal source 10 and has output circuits coupled through a line-scanning generator 38 and a field-scanning generator 39 to horizontal and vertical deflection windings 14 c, respectively, in the image-reproducing apparatus 14 An output circuit of the generator 38, for example, a tap on the horizontal deflection transformer therein is coupled to input circuits of the APC system 27 and the colorkiller circuit 36, both components of the system 12 and to be considered more fully hereinafter, for applying horizontal flyback pulses as gating signals to such units. An output circuit of the video-frequency signal source 10 is also

coupled to a soundsignal reproducing unit 40 which may comprise a conventional intermediate-frequency amplifier, an audio frequency detector, an audio-frequency amplifier, and a sound reproducer. Except for the details of combination of circuits in the image-reproducing system 12, all of the circuit components thus far described are conventional and well known, most of such components being fully considered in the aforesaid January 1954, I R E article entitled "Processing of the NTSC Color Signal for One-Gun Sequential Color Displays " Therefore, no detailed description of such circuit components is provided herein. GENERAL OPERATION OF RECEIVER OF FIG 1 Considering briefly now the operation of the receiver of Fig 1 as a whole and assuming the components of the inmage-reproducing system 12 and their combination to be conventional and as described in the aforesaid I R E. article, a desired composite color-television signal of the NTSC type is intercepted by the antenna system 11, selected, amplified, converted to an intermediate-frequency signal, further amplified, and the composite videofrequency signal component thereof detected in the unit 10 If color information is being transmitted, the composite video-frequency signal comprises conventional line and fieldsynchronizing components, a color burst synchronizing component, and the aforementioned luminance and chrominance signals. The luminance signal is translated through the luminance-signal channel, including the units 15, 16, 17, and 13 in the image-reproducing system 12, and applied to the cathode of the image-reproducing apparatus 14. The chrominance signal is translated through the amplifier 19 and converted by means of the axis selector 20 to g pair of chrominance signals One of these chrominance signals has only information re 70 presentative of red and blue, that is, is a subcarrier wave signal modulated only by an RBl component The other chrominance signal has information representative of green, that is, is a subcarrier wave signal modulated only 75 by a G-M component The converted signal having red land blue information is translated through ithe amplifier 35, the adder circuit 13, and applied to the cathode of the picture tube in the image-reproducing apparatus 14 80 In the modulator 23, the converted signal having green information is heterodyned with a signal having the third harmonic frequency of the initially applied subcarrier wave signal for developing a second harmonic chromin 85 ance signal including information representative of green The latter signal is translated through the filter network 24, the adder circuit 13, and applied to the cathode of the image-reproducing apparatus 14 The phasing 90 of the third harmonic signal is such that the developed signal, iafter translation through the network 24 and the adder

circuit 13, will apply the G-M information to the cathode of the picture tube in coincidence with the 95 impinging of the electron beam on the green phosphors. The chrominance signal in the output circuit of the amplifier 19 is also utilized in the synchronous detector 25 to derive a luminance 100 correction signal M-Y, the low-frequency components of which are translated through the filter network 26 and the adder circuit 13 for utilization in the image-reproducing apparatus 14 to correct for luminance errors in 105 herently caused by the chrominance signals in a single-gun tube such as utilized in the apparatus 14. To effect proper operation of the axis selector 20, the modulator 23, and the synchron 110 ous detector 25, that is, to control these units te operate in correct relationship with respect to the appropriate phases of the modulated subcarrier wave signal applied thereto, a sinewave reference signal of the same frequency 115 as the subcarrier wave signal is developed in the generator 28 and controlled in phase with respect to the subcarrier wave signal by means of the AP C system 27 The system 27 is responsive to the reference signal and the 120 color burst signal translated through the amplifier 19 and maintains the reference signal at a specific phase with respect to the color burst synchronizing signal and thus maintains the reference signal at specific phases with re 125 spect to the different modulation phases of the applied subcarrier wave signal These phase relationships are represented by the vector diagram of Fig la, the R-B modulation axis of the subcarrier wave signal is 29 clock 130 7 + 85,575 modulated by G-M information and Curve C represents the composite of the fundamental (F) and second harmonic (S) suboarrier wave signals Line M represents the corrected luminance-signal level, that is, the level for 70 the signal M. In the synchronizing-signal separator 317, the line and field-synchronizing signals are separated from the composite video-frequency signal and from each other land are utilized, 75 respectively, in the generators 38 and 3 > 9 to develop horizontal deflection land field deflection signals employed in the deflection windings 14 c to effect deflection of the cathoderay beam to scan a raster on the image screen 80 14 a The scanning of such raster, the intensity-modulation of the cathode-ray beam by means of the corrected lumlaance, fundamental, 'and second harmonic sub carrier signals applied thereto, and the differential vertical 85 deflection of the beam by means of the colorswitching signal applied to the grid 14 b combine to cause the intensity-Amodulated beam to impinge upon the phosphors for developing the different colors in correspondence with 90 intensity-modulation on such beam for these colors, thereby to reproduce a 'color image.

In addition to the picture signal, a sound signal is also intercepted land an intermediatefrequency sound signal developed in the 95 source 10 Such intermediate-frequency sound signal is then further amplified in the unit 40 and the audio-frequency components thereof are detected, additionally amplified, and utilized to reproduce sound in the unit 40 100 When a monochrome television signal is intercepted by the antenna 11, all of the units in the receiver of Fig 1 function in the manner just described except for some of the units used for developing color images Since no 105 color-synchronizing signal is received with a monochrome signal, the APC system 2 i 7 is unable to function and the 'color-switching signal developed by the generator 218, though it h'as a frequency of approximately 3 6 mega 110 cycles, is no longer locked in specific phase relation with line frequency The failure of the APC system 27 to function causes the color-killer circuit 36, in a manner to be explained more fully hereinafter, to develop a 115 negative bias potential which causes the modulator 23 and the detector 25 to become nonconductive and which changes the mode of operation of the selector 20 in a manner to be considered in detail hereinafter As a result, 120 only monochrome information is applied to the picture tube to cause the reproduction of a monochrome image To reproduce such monochrome image the intensity of the 'beam in the picture tube, during each cycle of ver 125 tical deflection caused by the color-switching signal, is such las to excite the different color phosphors to develop a composite neutral shade having a brightness range between black and white for every elemental area of the 13 Q wise, the G-M axis 40 counterclockwise, and the M-Y signal axis 161 ' clockwise or 1990 counterclockwise with respect to the phase of the color burst signal. The reference signal developed in the generator 28 is doubled to a second harmonic signal in the amplifier 34 and the phase of such second harmonic signal is delayed by means of the phase-delay circuit 32 so as to render the axis selector 20 cyclically and sequentially conductive in phase with the R-B and the G-M axes of the modulated subcarrier wave signal to develop a pair of subcarrier wave signals, one of which is, modulated solely by R-B information and the other of which is modulated solely by G-M information The manner in which the developing of these wave signals is effected will be described more fully hereinafter when considering the system 12 The signal developed in the generator 28 is controlled in phase by the phase-delay circuit 30 so as to have la specific phase with respect to the time of impingement of the beam in the picture tube on the green phosphors and such phase-controlled signal is then multiplied to a third harmonic signal in the amplifier 31, the latter signal being employed in the modulator 23 to develop' a second harmonic subcarrier wave signal

modulated by G-M information at a phase such that, when such developed signal is applied to the picture tube, the G-M information is applied to the green phosphors. The signal developed in the generator 28 is also controlled in phase by the circuit 33 to be in phase with the M-Y axis of the applied sub carrier wave signal, thereby to derive the M-Y component in the detector 25. The signal developed in the generator 28 is also applied through the push-pull amplifier 29 to the color-switching grid 14 b in the image-reproducing apparatus 14, the applied or color-switching signall having a specific phase with respect to the fundamental subcarrier wave signal translated through the amplifier 35 and which includes KR-B information at a specific phase The colorswitching signal also: has a specific phase with respect to the second harmonic subcarrier wave signal developed in the modulator 23 and which includes G-M color information at a specific phase The phase relations of the color-switching, fundamental and second harmonic wave signals are as represented by the curves of Fig lb The vertical lines G, R', R, 'G, B, and B represent the times of impingement of the cathode-ray beam on the green (G), red (R), and blue (B) phosphors. Curve F represents the phase of the fundamental subcarrier wave signal modulated by R-B information and it is apparent that the fundamental signal is in phase with the colorswitching operation Curve 'S represents the second harmonic subcarrier wave signal 78 '55175 6 785,575 image In practice, when the frequency of the intensity-modulation of the electron beam is in the vicinity of 3 6 megacycles, that is, of Pthe frequency of the color-switching signal, an excess of beam energy may be applied to gither the red or blue phosphors at the expense of less energy applied to the other thereof This results in red and blue areas in the reproduced image forming the spurious red and blue patterns Such excess does not occur in the green phosphors since they are excited by the ibeam at tvice the rate of excitation of the red and blue phosphors. DESCRIPTION OF IMAGE-REPRODUCING SYSTEM OF FIGS 1 AND 2. In describing the image-reproducing system 12 of Fig 1, reference will be made to Fig 1 to describe generally the combination of spedific units in accordance with the prevent invention and te Fig 2 to describe details of at least some of these units. The compatible inage-reproducing system 12 of Fig 1 comprises a circuit for supplying monochrome or color signals representative, respectively, of televised monochrome or color images More specifically, such circuit includes the output circuit of the video-frequency signal source 10 coupled to the input circuits of the

amplifier 19 and the delay line 15 Thie signal supplied by such circuit is, when color information is being transmitted, an NTSC type of composite video-frequency signal including a luminance signal having a band width of approximately 0-4 2 megacycles and a modulated subcarrier wave signal, conventionally designated as a chrominance sig-nal, having a mean frequency of approximately 3 6 megacycles and side bands extending over the frequency range of approximately 3 0-4 2 megacycles Such subcarrier wave signal includes modulation components at specific phases as represented by the vector diagram of Fig la When monochrome information is being transmitted, such supplied signal is a conventional monochrome signal having a band width of approximately 0-4 megacycles. The image-reproducing system 12 of Fig. 1 also includes image-reproducing apparatus, specifically the apparatus 14, including a plurality of parallel color-reproducing strips, means for developing an electron beam, deflection means for causing the beam to scan a raster on the strips, and color-swvitching means for cyclically moving the electron beam across the strips to reproduce a monochrome or color image Specifically, the image-reproducing apparatus i 14 is a single-gun focusmask type of picture tube fully considered in the aforementioned January, 1954 I R E. article The apparatus 14 includes a picture tube having an image screen 14 a on which color-reproducing strips, specifically, groups of phosphors for emitting green, red, and blue lights are deposited in an interleaved manner in the order, for each group, of green, red, green, and blue As conventionally employed, these strips extend horizontally Such tube also includes color-switching means, such as the control grid 14 b, coupled to the output 70 circuit of the push-pull amplifier 29 The grid 14 b is arranged to have a wire of one group of grid wires positioned behind each red phosphor and wire of another group of grid wires positioned behind each blue phos 75 phor The 3 6 megacycle signal developed in the amplifier 29 by means of the generator 2 'S is applied to the two groups of grid wires to effect a 3 6 megacycle vertical deflection to cause the electron beam, emitted from the 80 cathode of the picture tube and deflected to scan a raster on the phosphor strips by means of the deflection windings 14 c, to move vertically across each group of phosphor strips for each elemental area of the reproduced 85 image as each horizontal line is being scanned. Spurious color patterns tend to appear in reproduced monochrome images in such apparatus when signals applied to the cathode thereof have frequencies in the vicinity of the color 90 switching frequency, that is, frequencies of approximately 3 6 megacycles or, more specifically,

in the range of 3 0-4 2 megacycles. The compatible image-reproducing system also includes a signal-translating channel 95 coupled between the supply circuit and the beam-developing means for translating a band of the supplied signals having frequencies below the color-switching frequency for intensity-modulating the electron beam More 100 specifically, such channel includes the luminance channel comprising the delay line 15, the amplifier 16, the filter network 17, and the adder circuit 13 coupled in that order between the output circuit of the source 10 and 105 the cathode of the picture tube The filter network 17 has an upper cutoff frequencv of 3 megacycles and thus only signals in the range of 1-3 megacycles are translated through the luminance channel to inten 110 sity-modulate the cathode of the picture tube. -Finally, the compatible image-reproducing system of Fig 1 includes another signal-translating channel including auxiliary deflection means for developing a field in the path of 115 the electron beam Such other channel comprises the amplifier 19, the R-B and G-M axis selector 20, the filter network 21, the amplifier 22, and the auxiliary deflection winding 14 d This channel is coupled to the 120 supply circuit, specifically to the source 10, for translating a;band of the supplied monochrome signals having frequencies in the vicinity of the color-switching frequency for effecting deflection modulation of the electron 125 beam lengthwise of the phosphor strips on the image screen 14 a, thereby to provide highdefinition monochrome information when monochrome images are being reproduced and consequently to minimize the spurious red and 130 785,575 wor 23, 'and in the M-Y synchronous detector 25. Referring now to Fig 2 of the drawings, the color-killer circuit 36 is a control circuit coupled to the axis selector 20 for controlling 70 such selector to translate high-frequency lcomponents applied thereto cyclically to different output circuits when a color image is being reproduced land to one output circuit when monochrome images are being reproduced 75 The color-killer circuit 3,6 comprises a triode 50 having the cathode thereof grounded and the control electrode thereof coupled to the in-phase detector in, the APC system 27. The anode of the triode 50 is coupled through 80 the secondary winding of a transformer 51 and a load resistor '52 to the cathode of the triode Additionally, the junction of the secondary winding of the transformer 51 and the load resistor 52 is coupled through a low 85 pass 'filter network 53 and a switch 54 to an input circuit of the axis selector 20 The pass band of the filter '53 is such as to translate substantially only direct-current or very low frequency signals 90 The second harmonic amplifier 34 in Fig. 2 includes a triode '55 having the control electrode thereof coupled

through a biasing netporlk 56 to the output circuit of the referencesignal generator 28 Sand having the cathode 95 thereof grounded The anode of the tube 55 is coupled to a tapped terminal on 'a parallel-resonant circuit 57 having one of the terminals thereof connected through a load resistor 58 to a source of +B potential and the 10 ( other terminal thereof connected through 'a condenser 59 to a prarallel-resonant circuit in the phase-delay circuit 32 The resonant circuit '57 is tuned to approximately 7 2 megacycles, that is, to the second harmonic of the 105 mean frequency of the subcarrier wave signal. The resonant circuit 60 is tuned to approximately 7 2 megacycles and coupled to the tuned circuit 517 with such degree of inductive coupling or other reactive coupling, such as 110 capacitive, as represented by the condenser 59, or resistive, as to obtain the phase delay of the 7 2 megacycle reference signal required for use in the axis selector 20, now to be described in detail The reference generator 2 '8, second 115 harmonic amplifier 34, and phase-delay circuit 32 comprise means coupled to the selector 20 ' for controlling such selector cyclically to translate different segments of the highfrequency 'components supplied by the ampli 120 fier 19 through different ones of a pair of output circuits of the selector 20 when color images are being reproduced. The axis selector 20 is a signal-translating device including a pair of output circuits and, 125 specifically, includes a special type of electron tube 61 commercially known as a beamswitching tube, for example,' a type 6 AR-8 tube In addition to conventional cathode and control electrodes, the tube 61 includes 130 blue patterns in the reproduced monochrome i images More specifically, the band of supplied monochrome signals has frequencies in the range of 3 0-4 2 megacycles, as determined by the pass band of the amplifier 19, i and the auxiliary deflection winding 14 d is so positioned physically on the neck of the picture tube that the field developed by such winding is effective to cause minute horizontal deflection of the electron beam in magnitude and sense determined by the intensity and polarity of the high-frequency monochrome signal More specifically, such differential horizontal deflection is such as to vary the horizontal velocity of the beam in inverse relation to the magnitude of the high-frequency component. The additional signal-translating channel also includes the reference-signal generator 2 '8 the second harmonic amplifier 34, the phasedelay circuit 32, and the color-killer circuit 36 The generator 28 is a sine-wave generator for developing a signal which is substantially equal in frequency to the mean frequency of the modulated subcarrier wave signal translated through the amplifier 19,

that is, for developing a signal of approxinately 3 16 megacycles The phase and frequency 'of the signal developed in the generator 2,8 are controlled by the automatic-phase-control system 217 which may be of a type described in an article entitled " The DC Quadricorrelator: A TwoMode,Synchronization System," published in the January, 1954 issue of the PROCEEDINGS OF THE I R E at pages 288-299, inclusive The details of such an automaticphase-control system are particularly considered at page 293 of this 'article with reference to Fig 5 thereof As described in such article, the system 27 includes the conventional quadrature-phase detector for controlling the phase of the signal developed 'in the generator 28 so that the reference signal has a specific phase relation with respect to the modulated suboarrier wave signal and also includes an in-phase detector The in-phase detector is utilized to improve the automatic phase control of the system 27 and additionally develops a unidirectional potential which has a maximum magnitude when the signal developed in the generator 28 is in proper phase relation with respect to the modulated subcarrier wave signal In the circuit described in such article, such potential is negative when the generator 218 'is properly synchronized and is utilized by the color-killer circuit 36 to control the state of operation of circuits in the chrominance and luminance channels of the receiver The color-killer circuit 36 has input circuits coupled to the inphase detector in the APC system 27 and to a tap on the horizontal transformer in the line-scanning generator 38 The output circuit of the color-killer circuit 36 is coupled to control circuits in the selector 20, in the modula7 + 85,57 + 5 a pair of deflection electrodes 62 a, 62 b and a pair of anodes The cathode of the tube 61 is coupled through a biasing resistor 63 to ground while an electron intensity control electrode of the tube 61 is coupled to the output circuit of the amplifier 19 Another grid electrode of the tube 61 is grounded, this electrode being conventionally known as the fucusing electrode, and the third grid electrode, known as the accelerating electrode, is coupled directly to a source of potential + B. The deflection electrodes 62 a, 62 b are coupled to opposite terminals of a tuned secondary circuit 64 of a transformer 65, the resonant frequency of the tuned circuit being approximately 7 2 megacycles The primary winding of the transformer 65 is coupled to the output circuit of the phase-delay circuit 32 and the secondary winding of such transformer has a center tap connected to ground The deflection electrode 62 b is coupled to the tuned circuit 64 through a condenser 65 a and is also coupled through an isolating resistor 66 to the output circuit of the color-killing circuit 36 The anodes of the tube 61 are components of a pair of anode output circuits, specifically being individually coupled through different ones of resistors 67 and

68 to the source of +B potential One output circuit is coupled to the R-o B amplifier 35 and the other output circuit is coupled to the modulator 23 and through ia condenser 73, the filter network 21, and the amplifier 22 to the auxiliary deflection winding 14 d The filter network 21 comprises a, pair of coupled damped tuned circuits,70 and 71 each tuned approximately to a mean frequency of 3 6 megacycles and being sufficiently broadly tuned to have a pass band of approximately 3 0-4 2 megacycles The amplifier 22 is a conventional cathode-follower type of power amplifier for developing signals for application to the deflection winding 14 d. OPERATION OF IMAGE-REPRODUCING SYSTEM OF D'IG 1 The general operation of the image-reproducing system 12 of Fig 1 has been prevriously described herein and, therefore, the specific operation of only that portion of the system -which is modified in accordance with the present invention will be considered in detail. The luminance channel including the units 15, 16, 17, and 13, the channel for developing the second harmonic subcarrier wave signal modulated by information representative of green and including the units 30, 31 23, and 24, and the channel for developing the M-Y correction signal including the units 33, 25, and 26 operate in a conventional manner such as described in the January, 1954 I R E. article previously referred to herein and entitled " Processing of the NTS'C Color Signal for One-Gun Sequential Color Displays " The operation of the axis selector 20 and the units 21, 22, and 14 d coupled to the output circuit thereof as well as of the color-killer circuit 36 will be considered in some detail. Before considering the operation of the last-mentioned units, as more fully represen 70 ted in Fig 2, it will be helpful to consider in -some detail the problem which applicants' image-reproducing system is designed to solve. As previously mentioned, when an image-reproducing apparatus of the focus-mask type, 75 such as represented by the apparatus 14 of Fig. 1, is reproducing a monochrome image, spurious red and blue patterns tend to appear in such image These patterns result from the combined effect of a high-frequency intensity 80 modulation of the electron beam in the picture tube, a frequency in the vicinity of 3.6 megacycles, and of a 3 6 megacycle colorswitching signal If the intensity-modulation and the color switching happens to be in 85 phase, the positive peak of the beam intensity wvill occur as one phosphor is being excited, for example, as the red phosphor is excited and the negative peak will occur as the blue phosphor is excited, since these phos 90 phors are excited at a 3 6 magacycle rate. This will result in an excess of red over blue where no such excess should exist As the phase relations of the color-switching operation

and the intensity-modulation of the beam 95 vary from such in-phase relation caused, for example, by a small difference in the frequency of the two, there will tend to be periods when the blue is in excess and other periods when the red is in excess As a result, 100 spurious red and blue patterns appear in the monochrome image If the operation of the picture tube were linear, then none of these effects would appear for green because the beam impinges on the green phosphors at a 105 rate twice that of impingement on the red and blue phosphors However, the operation is not linear and rectification of the signal occurring in coincidence with the impingement of the beam on the green phosphors 110 does occur resulting in spurious green patterns These patterns are not,as evident or present to the same degree when a color image is being reproduced because the inter-laced relationship of the color information with line 115 frequency causes any such patterns to have low visibility Since there is no such interlacing when a monochrome image is being reproduced, due to the lack of synchronization of the color-switching operation, with line fre 120 quency, these patterns tend to be highly visible, to destroy all high-definition information in the monochrome image,land otherwise deleteriously affect the reproduced monochrome image 125 The beatin, of the high-frequency components and the color-switching operation causes the proportions of red, green, and blue lights emitted from an elemental area to become unbalanced toward red or blue If the 130 78 '5,5175 wave signal to the control electrode In this manner, the output signal developed in the circuit including the upper 'anode includes 'a subcarrier wave signal at fundamental frequency modulated substantially only along the 70 G-M axis 'and the output signal in the circuit including the lower anode includes a fundamental subcarrier wave signal modulated substantially only along the R-B axis Since the G-M 'and R-B axes are separated by 75 approximately 70 and the operation of the selector 20 is based on a quadrature relationship, for these axes, the output signals are not pure R-B and G-M signals but are sufficiently pure for utilization If desired, 'a cor 80 rection network for cross coupling the outputs may be employed to improve the degree of purity The R-B and G-M wave signals are utilized in the manner previously described herein to reproduce a color image 85 When a color signal is being received, the in-phase detector in the system 27 develops a negative potential which is applied to the grid of the triode 50 in the color-killer circuit 36 to render such trio de nonconductive 90 Therefore, during such period of time no po/tential is developed in the output circuit of the unit 3 ( 6 and no bias potential is applied from the unit 36 to the deflection electrode 162 b in the axis selector 20 Consequently, the 95 tube 61 in the unit 20 can function in its normal manner However, when a monochrome signal is

being received, the system 27 does not develop a negative bias potential and the tube 50 is rendered conductive periodically 100 when positive-going flybiack pulses are applied to the anode thereof through the transformer 51 This results in 'a net negative potential being developed across the load resistor 52. This negative potential is applied through the 105 resistor 616 to the deflection electrode 162 b resulting in 'a continuous deflection of the beam in the tube 161 away from the electrode 62 b toward the electrode 62 a Alternatively, the same effect can be accomplished when color 110 signals are being received by connecting the blade of the switch 54 to the negative bias potential source 'C, if the viewer wishes to view a monochrome Image instead of a color image When such negative potential is 115 applied to' the deflection electrode 62 b, the electron beam impinges solely on the upper anode since the intensity of the 7 2 megacycle signal applied to the deflection electrodes 62 a and 62 b is insufficient to overcome the 120 high negative bias on the deflection electrode 62 b Consequently, the 3 0-4 2 megacycle components:appliedl to the control electrode of the tube:61 are translated only to the output circuit including the upper anode and 125 translated through the filter network 21 and the deflection amplifier 22 for application to the auxiliary deflection winding 14 d This results in the high-frequency monochrome information, being applied to the electron beam 130 high-frequency information is applied 'as differential horizontal deflection of the electron beam to sharpen edges in the reproduced monochrome image, then, though the position of the beam on the red, green, and blue phosphors is changed on each phosphor in accordance with the magnitude and sense of the highfrequency information, the relative intensities of the red, green, and blue lights for each elemental area 'are not disturbed Consequently, no excess of one or another color occurs and the spurious color patterns are minimized. The deflection modulation also eliminates the spurious green patterns because high-frequency information in coincidence with the impingement on 'the green phosphors is no longer introduced by means of the nonlinear intensity effect of the beam Therefore, all monochrome high-frequency information is applied to the picture tube as horizontal deflection modulation of the be'am The selector is conditioned to operate to apply highfrequency information as intensity-modulation when a color image is being reproduced and conditioned to operate ito apply the high-frequency information as deflection modulation when a monochrome image is being reproduced Referring to Fig 2 of the drawings, the reference signal developed in the output circult of the generator 28 is applied to the harffonic amplifier; 34 wherein it is doubled to become a second harmonic or 7 2

megacycle signal The second harmonic signal is controlled in, phase by the phase-delay circuit 32 and coupled through the transformer '65 for application with opposite phases to the pair of deflection electrodes '62 a land 62 b The 3 04.2 megacycle signal translated through the amplifier 19, regardless of whether it is a monochrome or color signal, is applied to the control electrode of the tube '61 In operation the deflection electrodes 62 a and 16,2 b in the tube 61, if a color image is being reproduced, cause deflection of the electron beam emitted. from the cathode therein to cause such beam to impinge on the anodes therein at a 7 2 megacycle rate If the deflection operation is properly phased by controlling the phasing of the 7 2 megacycle reference signal with respect to the modulated sub carrier wave signal applied to the control electrode in the tube 61, then the electron beam is directed on the upper anode of the tube 161 in coincidence with the application of the phase of the modulated suboarrier wave signal which includes information representative of green, that is, in coincidence with the application of the G-M axis of the wave signal to the control electrode of the tube Similarly, the electron beam is caused to impinge on the lower anode in coincidence with the application of that phase of the subcarrier wave signal including red and blue information, that is, in coincidence with the application of the R-B axis of the 1785 C 57 '5 as differential horizontal deflection, thereby effecting reproduction of such high-frequency information in the reproduced image without causing the reproduction of spurious color patterns. If the brightness in the image is changing from one level to a higher level, the differential horizontal deflection has the effect of accelerating the horizontal sweep of the beam as the intensity of the beam starts to change from the one level and decelerating the horizontal sweep as the intensity of the higher level is approached Of course, the acceleration and deceleration occur in -coincidence with changes in beam intensity only if such changes represent high-definition information such as the edge of a vertical bar or any object having sharp, distinct, vertical edges. Otherwise, there would 'be no high-frequency information received and, consequently, the auxiliary deflection winding would not develop an accelerating or retarig field. D Esc RIPT Io N AND OPERATION OF PORTION OF IMAGE-REPRODUCING SYSTEM OF -FIG 3 ' ahe image-reproducing system described with reference to Figs 1 and 2 utilizes some of the fircts of the chrominance channel in a dual capacity These circuits function in one manner when, a color image is being reproduced and function in a different manner, to effect deflection modulation of the electron beam in the picture tube

in response to highfrequency monochrome components, when, a monochrome image is being reproduced However, it is not essential that circuits in the chrominance channel be so used, and, in fact, under some conditions it may not ibe desirable ito employ such circuits Alternatively, the high-frequency components of the composite video-frequency signal may be translated through an auxiliary luminance channels as represented in Fig 3, for application of such high-frequency components to the auxiliary deflection winding Since many of the units of Fig 3 are identical with units in Figs 1 and 2 such are identified by means of the same reference numerals. In, Fig 3, the luminance channel including the units 1 t 5, 16, 70, and 13 is modified to translate directly, for intensity-modulation of the electron beam developed in the picture tube, only those video-frequency components in the range of, for example 0-1 L 8 megacycles by proportioning the pass band of a filter network 70 to effect such result An auxiliary luminance channel coupled to the output circuit of -the delay line 15, has, in cascade in the order named, a filter network 71, the amplifier 22, and the auxiliary deflection winding 14 d The filter network 71 is proportioned 'to have a pass band of, for example, 18-42 megacycles for translating the high-frequency video-frequency components through such auxiliary channel The RB and G-M axis selector in the chrominance channel is modified in that, as represented in Fig 3, it has output circuits coupled only to the R-B amplifier 35 and to the modulator 23 and is further modified in having the color 7 C killer circuit 36 coupled to an intensity control electrode therein rather than to one of the deflection electrodes as in Figs 1 and 2. Considering now the operation of the portion of the image-reproducing system repre 75 sented by Fig 3, when a monochrome image is being reproduced, that portion of the composite video-frequency signal supplied from dhe source 10, having components in the frequency range of 0-1 8 megacycles, is trans 80 lated through the units 15, 16, 70, and 13 and applied to the cathode of the picture tube in the image-reproducing apparatus 14 That portion of the same composite video-frequency signal having components in the fre 85 quency range of 1 18-4 2 megacycles is translated through the delay line 15, the filter network,71, amplified in the unit 22, and utilized to effect differential horizontal deflection modulation by means of the auxiliary deflec 90 tion winding 14 d When a mono-chrome image -is being reproduced, the chrominance channel is effectively rendered inoperative by means of the color-killer circuit 36 and, specifically, the axis selector 72 is made noncon 95 ductive during this period. Although the operation just explained results in some duplication of the high-frequency components applied to the picture tube when a color

image is being reproduced, for 100 example, the duplication caused by the translation of components in the frequency range of 3 0-42 megacycles through both the network 71 and the amplifier 22 to effect horizontal deflection modulation -and through the 105 amplifier 35 to effect some intensityodulation of' the beam' in the picture tube, such duplication is usually beneficial since there tends to be a lack of sharpness in' reproduced color images and such excess of high-fre 110 quency information tends to make such images more crisp and sharp. The visibility of red and blue spurious patterns in a monochrome image reproduced by an irmage-reproducing system, including the 115 circuits of Fig 3, is so diminished as to be substantially nonexistent This substantial reduction -is caused by utilizing no frequency components having frequencies higher than one-half the frequency of the color-switching 120 signal, that is, having frequencies higher than 1.8 megacycles for intensity-modulation of the electron beam in the picture tube All components having frequencies higher than 1 8 megacycles are utilized to effect differential 125 horizontal deflection modulation Consequently, any tendency of the 3 6 megacycle color-switching signal to heterodyne with the intensity-modulation signals of the electron beam does not result in developing low-fre-'130 785,57,5 785,575 11 quency beat signals in the frequency range of 0 ( 1 8 megacycles and therefore, any such beat signals are practically invisible.


* GB785576 (A)

Description: GB785576 (A) ? 1957-10-30

Improvements in or relating to the catalytic conversion of gasolinehydrocarbons


A high quality text as facsimile in your desired language may be available amongst the following family members:

DE1028728 (B) NL101545 (C) DE1028728 (B) NL101545 (C) less Translate this text into Tooltip



PATENT SPECIFICATION 78, Date of Application and filing Complete Specification Dec 30, 1955 ao.37385/55. Application mode in United States of America on Dec 31, 1954. Complete Specification Published Oct 30, 1957. Index a; ' -c ass 2 ( 3), B 2. International Cassificaton: COAMIPLET 1 E SPECIFICATION Improvetnents in er relat,-tg to the Catalytic Conversion of C'e Li R Le H v T xbo Ts We UNIVERSAL Ott PP Thn TT,-1 r 5,576 EPRATA SECIFICATION NO O 785,5 Th Page 3, line 109, for Iscapen read "scope'. page 4, line i 5, for ncycle' read 'cyclic 5, Page 6, line 83, after nfurther 1 ' insert othe, Pa Ge 7, line 53, for frefilnaten read nraffinatem. Page 7, line 54, after "fractlon"t insert "comprising lsohexanes froi a hligher boiling rafflinate fraction". Page 8, line 4, for icomapentsn read "components". THE PATENT OFFICE, 3 gist December, 1957 t Uy XLt:conainons that must be mintained in order to saisfactorily unarade the hieher boiling Daraffinic constituents of the feed ar too Qevere for come of the cther constituents The result is that an appreciable part of the feed stock is unnecessarily lIrico Pri S 145 6 d v uic present invention a mixture of hydrogen, a fresh gasoline fraction and a high boiling paraffinic recycle stock prepared as hereinafter described is subjected in the reforming zone to reforming at an elevzated temperature and pressure in the presence of a catalyst comprising D 13 oi 82 oi 2 (i)13624 150 12/57 R 9 a O : ' 1 1 1 1 \ -,114 % j,t ' lPATENT SPECIFICATION

785,576 Date of Application and filing Complete Specification Dec 30, 1955 " I g +dffi No 37385/55. Application made in United States of America on Dec 31, 1954. Complete Specification Published Oct 30, 1957. Index at Acceptanc:-Class 2 ( 3), B 2. International Classification: o 6 07 c. COMPLETE SPECIFICATION Improvenients in or relating to the Catalytic Conversion of GacAtin Le 1-ydrocarlbbons We, UNIVERSAL OIL PRODUCTS COMPANY, a Corporation organised under the Laws of the State of Delaware, United States of America, of No 30, Algonquin Road, Des Plaines, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to the catalytic conversion of hydrocarbons boiling within the gasoline range It is more specifically concerned with a novel combination of reforming and solvent extraction. The recent developm ents in the automotive industry have increased the demand for high octane numbered gasolines and the petroleum industry has been striving to keep up with these demands One nrocess that has achieved great commercial acceptance is the catalytic reforming process The term " reforming " is well known in the petroleum industry and refers to the treatment of gasoline fractions to immrove the anti-knock characteristic thereof. A highly successful and economical reforming process is described in the United Kingdom Patent No 657,565 filed November 23, 1948. However, the present reforming processes are all limited by decreasing yields at increasing octane numbers There are also other limitations For example, when a full boiling range strainht-run gasoline or a relatively wide boiling range naphtha is reformed in the presence of a catalyst that promotes dehydro)zenation of naphthenes, dehydrocvclization of paraffins and bvdrocracking of parafins, relatively poor yields and considerable fouling of the catalyst are obtained when the operation conditions are selected to obtain large octane number appreciation This apparentlv is due to the fact that the relatively severe operating conditions that must be maintained in order to satisfactorily upgrade the higher boiling paraffinic constituents of the feed are too Severe for some of the other constituents The result is that an appreciable part of the feed stock is unnecessarily lPrice ?ribg l 4 s 6 d converted to gases and to catalyst carbon. Thus; under the usual conditions of operation, the yield of liquid product and the catalyst life are limited, to a considerable extent,

by and primarily dependent upon the decomposition and carbon forming tendencies of the higher boiling constituents The reforming process of the present invention largely overcomes these objectionable features of the prior art reforming processes. It is an object of the present invention to reform a full boiling range straight-run gasoline, or a relatively wide boiling fraction thereof, in such a manner that increased yields of reformate and longer catalyst life are obtained while producing a liquid product of the desired quality. According to the present invention gasoline hydrocarbons are reformed by a process which comprises supplying a fresh gasoline charge which contains paraffins and naphthenes to a reforming zone and therein subjecting it in the presence of hydrogen to a catalyzed reforming which includes the essential reactions of dehydrogenation of naphthenes and dehydrocyclization and hydrocracking of paraffins, separating the normally gaseous reaction products from the normally liquid reformed product, subjecting the latter to an extraction treatment and therein separating the same into a rafflinate poor in aromatic hydrocarbons and into an extract rich in aromatic hydrocarbons, subjecting the raffinate to fractional distillation and therein separating a low boiling fraction comprising isohexanes from a higher boiling raffinate fraction containing normal hexane, and returning this higher boiling raffinate fraction to the reforming zone and subjecting it therein to the catalyzed reforming reaction in admixture with the fresh gasoline charge. In a more specific embodiment of the present invention a mixture of hydrogen, a fresh gasoline fraction and a high boiling paraffinic recycle stock, prepared as hereinafter described, is subjected in the reforming zone to reforming at an elevated temperature and pressure in the presence of a catalyst comprising so 785,576 platinum, alumina and combined halogen, the reformed product is fractionated to remove normally gaseous components, the remaining product fraction, namely the normally liquid reformed product is introduced into an extraction zone wherein it is treated with a selective solvent having a relatively higher solvent power for aromatic hydrocarbons, a raffinate rich in paraffinic hydrocarbons and an extract phase containing the solvent and a substantial amount of the aromatic hydrocarbons of the reformed product are separately removed from the extraction zone, the extract phase is treated to separate the solvent from the aromatic hydrocarbons, the raffinate is fractionated separating a low boiling paraffinic fraction comprising isohexanes and lower boiling paraffins from a higher boiling raffinate fraction containing normal hexane, at least a portion of the low boiling fraction is returned to the extraction zone and at least a portion of the high boiling paraffinic

fraction is recirculated to the reforming reaction. In the present process a fresh gasoline fraction is reformed in admixture with a paraIfinic recycle stock in the presence of hydrogen Hydrogen is separated from the reforming step effluent and is recycled to this reforming step Net product hydrogen may be withdrawn The remaining products are fractionated to reject the gaseous hydrocarbons produced in the process and the resultant liquid product is extracted in an extraction zone to separate the aromatics therefrom The raffinate from the extraction zone is preferably fractionated to remove a fraction boiling lower than normal hexane since these lighter components are usually high in octane number and their further reforming does not result in substantial octane number appreciation; therefore it is usually not economical to reform this lighter paraffinic fraction The higher boiling fraction of the raffinate is then recycled to the reforming zone In some cases the raffinate may contain constituents which are so heavy that they tend to deposit carbon on the catalyst in the reforming zone; it is preferred to also remove these heavy constituents from the raffinate The raffinate fraction that is recycled to the reforming zone in the preferred mode of operation, therefore, is a middle cut of the raffinate that is removed from the extraction unit The separated aromatics may be recovered as such and may be used, for example, in solvents However, they preferably are blended with the lower boiling fraction of the raffinate to produce a reformed gasoline of high quality. A feature of the present process is that mild processing conditions may be employed in the reforming step minimizing undesirable side reactions which otherwise keduce yields of useful gasoline products Recycling of the low octane number, high boiling paraffins results in their being dehydrocyclized to aromatics and/ or their being converted to lower boiling, high octane number paraffins without the excessive production of gaseous hydrocarbons that would result, if these higher boiling paraffins were substantialy completely reacted in one pass in a reforming operation at conditions of high severity High severity single pass operation is also not desirable from considerations of the chemical equilibria involved; as in such single pass operations the aromatics present in the product limit the extent to which such aromatics can be formed from naphthenes and paraffins In contrast, however, the use of the present process involves the removal of a substantial portion of the product aromatics from the recycle to the reaction zone which thus permits the formation of additional aromatics unrestricted by the limitations of chemical equilibria Similarly, the isomerization of low octane rating straight chain paraffins to higher octane quality branched structure paraffins is an equilibrium chemical reaction As the isomerization of normal hexane is important to achieve

in upgrading gasolines, due to the very limited extent that it undergoes dehydrocyclization at reasoable operating conditions, a feature of the present process is the continuous removal of isohexanes and the continuous recirculation of normal hexane to the reaction zone thus obtaining complete conversion of low octane normal hexane to much higher quality isohexanes without any restriction in yield due to chemical equlibrium considerations. The aromatics are separated from the paraflins and naphthenes of the reformate (that is the normaly liquid reformed product) for several reasons One reason is that recycling the aromatics results in lower over-all yields of reformate Dresumably due to conversion of the aromatics to gaseous hydrocarbons and to hydrocarbons boiling above the gasoline range nmother reason is that high concentrations of aromatics in the reaction zone tend to result in a greater carbon decomposition and consequently a shorter process Deriod Still another reason is that high concentrations of aromatics in the reaction zone tend to suppress the dehydrogenation of naphthenes to aromatics and to suppress the dehydrocyclization of paraffins to aromatics, said dehydrogenation and said dehydrocyclization being equilibrium reactions By eliminating low octane number, high boiling paraffins from the final product and recycling them to the reaction zone the end product is a reformate of high quality even though the lower boiling portions of the charging stock have never been subjected to the relatively severe operating conditions that previously have been thought to be necessary to produce high quality reformate. The charge stocks that may be reformed in accordance with the present process comprise hydrocarbon fractions that boil within the gasoline range and that contain naphthenes 1)S 785,576 and paraffins The preferred stocks are those i: consisting essentially of naphthenes and para r ffins, although minor amounts of aromatics and r even of olefins also may be present This pre g ferred class includes straight-run gasoline, natural gasoline and the like The gasoline r fraction may be a full boiling range gasoline 1 having an initial boiling point substantially from 100 C to 380 C, and an end boiling I point substantially from 1770 C to about 218 c C., or it may be a higher boiling fraction corm monly referred to as naphtha and having an I initial boiling point substantially from 660 C f to 1210 C, and an end boiling point substanti l ally from 1770 C to 2180 C Mixtures of the various gasolines and/or gasoline fractions may also be used and thermally cracked and/or catalytically cracked gasolines may also be used as charging stock, however, when these unsaturated gasoline fractions are used, it is preferred that they be used in admixture with a straight-run or natural gasoline fraction, or else hydrogenated prior to use as charging stock for the

present process. The catalysts that may be used in the reforming step of this invention comprise those reforming catalysts that promote dehydrogenation of naphthenic hydrocarbons and hydrocracking of paraffinic hydrocarbons. Starting with a paraffinic hydrocarbon, from a yield-octane standpoint it is preferable to upgrade the paraffinic hydrocarbon by dehydrocyclizing the same to an aromatic rather than by cracking the paraffinic hydrocarbon Since the recycle raffinate to the reforming zone consists predominantly of paraffinic constituents it is best to upgrade this recycle stream by dehydrocyclisation Therefore, it is preferred that the catalyst in the reforming zone be such that it has a substantial amount of dehydrocyclization activity A satisfactory catalyst comprises a platinum-alumina-silica catalyst of the type described in the United States of America Patent No 2,478,916 issued August 16, 1949, the platinum being present in an amount of from 0 2 gram to 2 0 grams per 100 cubic centimeteres of final catalyst A preferred catalyst comprises a platinumn-alumina-combined halogen catalyst of the type described in the United Kingdom Patent No 657,565 filed November 23, 1948 Other catalysts such as molybdena-alumina, chromia-alumina, and platinum on a cracking catalyst base may be used It has been found that catalysts of the platinum-alumina-combined halogen type, wherein the halogen content lies within the range of from about 0 1 % to about 3 % by weight of the final catalyst, especially those that contain about 0 01 % to about 1 % by weight of platinum and from about 0 1 % to about 1 % combined fluorine or those that contain about 0 1 % to about 3 0 % combined chlorine are especially effective and economical in the present process because of the long life they exihibit, and also because they promote somerization reactions of both paraffins and iaphthenes and paraffin dehydrocyclization eactions as well as the naphthene dehydroenation and paraffin hydrocracking reactions. The operating conditions maintained in the 70 reforming step of this process should be such hat substantial conversion of naphthenes to aromatics and relatively mild hydrocracking of paraffins are induced Further the operating conditions should be such that there is substan 75 Jal conversion of paraffinic compounds to aromatics by dehydrocyclization It is also preferred that process conditions be used which result in only minor amounts of olefins being present in the product When employing plati 80 num-alumina-combined halogen catalyst the reforming process will be effected at a temperature within the range of from about 316 C to 5380 C, pressure within the range of from about 3 4 to about 68 atmospheres, and a 85 weight hourly space velocity of from about 0.5 to about 20 The weight hourly space velocity is defined as the weight of oil per hour per weight of

catalyst in the reaction zone The reforming reaction is conducted in the pre 90 sence of hydrogen In one embodiment of the process sufficient hydrogen will be produced in the reforming reaction to furnish the hydrogen required in the process; and therefore, it may be unnecessary to introduce hydrogen 95 from an extraneous source or to recycle hydrogen within the process However, it will be preferred to introduce hydrogen from an extraneous source, generally in the beginning of the operation, and to recycle hydrogen 100 within the process in order to be assured of a sufficient hydrogen atmosphere in the reaction zone The hydrogen present in the reaction zone will be within the range of from about 0 5 to about 20 mols of hydrogen pepl mol of 10 > hydrocarbon In some cases the gas to be recycled will contain hydrogen sulfide introduced with the charge or liberated by the catalyst, and it is within the scape of the present invention to treat the hydrogen containing gas 110 to remove hydrogen sulfide or other impurities before recycling the hydrogen to the reforming zone. The effluent from the reforming zone is usually passed to a stabilizer which effects 115 separation of the normally gaseous material which comprises hydrogen, hydrogen sulfide, ammonia, and hydrocarbons containing from one to four carbon atoms per molecule, from the normally liquid hydrocarbons A more con 120 centrated aromatic fraction is then obtained in accordance with the present invention by subjecting the reformate, containing aromatic hydrocarbons, to a solvent extraction process subsequent to being suitably treated to 125 improve its characteristics as a charge stock for the solvent extraction processes. Solvent extraction processes are used to separate certain components in a mixture from other components thereof by a separation pro 130 785,576 cess based upon a difference in solubility of the components in a particular solvent It is frequently desirable to separate various substances by solvent extraction when the substances to be separated have similar boiling points, are unstable at temperatures at which fractionation is effected, or form constant boiling mixtures It is particularly desirable to separate aromatic hydrocarbons from a petroleum fraction containing these aromatic hydrocarbons by solvent extraction because a petroleum fraction is normally a continuous mixture of hydrocarbons whose boiling points are extremely close together and because the -15 petroleum fraction contains numerous cycle compounds which tend to form constant boiling or azeotropic mixtures Since the basis of a solvent extraction separation is the difference in solubility in a given solvent of one of the substances to be separated from the others, it is apparent that the more extreme this difference, the easier will be the separation, and an easier separation reflects itself process-wise, in less expensive equipment

and greater yields per pass as well as in higher purity of product. A particularly preferred solvent for separating aromatic hydrocarbons from non-aromatic hydrocarbons is a mixture of water and a hydrophiliq organic solvent Such a solvent may have its solubility regulated by adding more or less water Thus by adding more water to the solvent, the solubility of all components in the hydrocarbon mixture are reduced, but the solubilitv difference between the components is increased This effect is reflected process-wise in fewer contacting stages required to obtain a given purity of Droduct, however, a greater throughput of solvent must be used in order to obtain the same amount of material dissolved Suitable hvdrophilic organic solvents include alcohol, glycols, aldehydes, glycerine and phenol Particularly preferred solvents are diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and mixtures of two or more of these, in admixture with from about 2 ' to about 30 % by weight of water Other hydrophilic solvents such as, for example, sulfur dioxide, may be used. In classifying hydrocarbon and hydrocarbon type compounds according to increasing solubility in such a solvent, it is found that the solubility of the various classes increases in the following manner: the least soluble are the paraffins followed in increasing order of solubility by naphthenes olefins, diolefins, acetylenes, sulfur, nitrogen, and oxygen-contaming compounds and aromatic hydrocarbons It may thus be seen that a charge stock which is rich 60) in unsaturated compounds will present a greater problem in solvent extraction than a saturated charge stock since the unsaturated compounds fall between the paraffins and arm matics in solubility Further difficulty in having unsaturated compounds in the feed is that they tend to polymerize at higher temperatures to form sludges and other undesirable materials which causes great difficulty in processing equipment It may be seen that an ideal charge to solvent extraction is one containing para 70 ffinic and aromatic hydrocarbons exclusively. The paraffinic compounds also differ in their relative solubility in the solvent The solubility appears to be a function of the boiling point of the paraffins, with the lower boiling or 75 tighter paraffins being more soluble than the higher boiling or heavier paraffins Therefore, when heavy paraffins are dissolved in the solvent, they may be displaced from the solvent by adding lighter paraffins thereto In an 80 embodiment of this invention it is preferred to recycle the heavier paraffins to the reforming zone and therefore a light paraffin is preferably charged to the extraction zone to displace these heavier paraffins from the solvent 85 by putting the heavier paraffins into the raffinate phase. Additional features and advantages of this invention will be apparent

from the following description of the accompanying drawing 90 which illustrates a particular method for conducting a gasoline upgrading operation in accordance with the present invention. Referring now to the drawing, a straightrun gasoline fraction having an initial boiling 95 point of 930 C and an end boiling point of 2040 C is passed through line 1 into fractionator 2 In fractionator 2, the gasoline fraction is fractionated and an overhead fraction passes overhead and is withdrawn through line 100 3 Heat is provided for the fractionation by reboiler 11 which is connected to fractionator 2 by line 10 and line 12 The overhead fraction in line 3 is passed through cooler 4, continues through line 5 an into receiver 6 A 105 portion of the liquefied overhead fraction is returned to fractionator 2 through line 7 as reflux for column 2 This fractionation is desirable when the fresh feed contains dissolved water and/or dissolved gases therein 11 ^ since these substances are often undesirable in the reforming zene The di-solved gases pass overhead through line 3 and are removed from receiver 6 through line 9 The water in the feed also tends to pass overhead through line 115 3, due to a partial pressure effect of water even at a fractionator top temperature much below that corresponding to its normal boiling point of 1000 C, and mav be removed from receiver 6 through line 8 A low boiling liquid hydro l ?O carbon stream may also on occasion be removed from receiver 6 by means of line 8 in order to control the initial boiling point of the reforming reactor charge stock The bottoms of fractionator 2 are withdrawn 125 through line 13 and are commingled with a paraffinic recycle stream in line 91 and the combined stream in line 14 is introduced to an intermediate point in rerun:edistilling column 15 130 785,576 Rerun column 15 is necessary when the fresh freed or the recycle raffinate in line 91 contains heavy components, that is components boiling above about 218 ' C since it has been tound that heavier components tend to deposit carbon on the catalyst and deactivate the catalyst that is used in the reforming operation. t.he parathnic recycle in line 91 is preferably redistilled since the recycle stream usually has therein undesirable heavier components The undesirable heavy components may be paraiunic and/or aromatic When the fresh feed also has heavy components present therein both of the streams may be redistilled at the same time as illustrated in the drawing However, when the fresh feed does not contain heavy components, the fresh feed need not be redistilled but may be sent directly to the reforming operation Heat is provided to rerun column 15 by reboiler 22 which is connected to rerun column 15 by line 21 and line 23. Heavy components are removed from column through line 24 The overhead fraction from column 15 passes through line 16, cooler 17, line 18 and

into receiver 19 A portion of the liquid in receiver 19 is withdrawn and returned to column 15 through line 20 as reflux The charge to the reforming operation is withdrawn from receiver 19 through line 25, is picked up by charge pump 92 and passed through line 93, commingles with hydrogen recycled through line 34, and the combined stream is passed through heater 94 and thence through line 26 into reforming reactor 27 The commingled stream of charge stock and recycled stock and recycled hydrogen passes into heater or furnace 94 wherein it is heated to a temperature of 4820 C The heated stream then passes into reforming reactor 27. Reforming reactor 27 contains a bed of spherical catalyst of approximately 3 2 millimeters average diameter containing alumina, 0.3 % platinum, 0 5 % combined fluorine, and 0.1 % combined chlorine The pressure in the reactor is 34 atmospheres, the weight hourly space velocity is 4, and the hydrogen to hydrocarbon mol ratio is 5 to 1 During the passage of the charging stock through reactor 27, the bulk of the naphthenes containing seven or more carbon atoms per molecule are dehydrogenated to the corresponding aromatics and a minor portion of the paraffins are hydrocracked to lower boiling paraffins Some isomerization of the paraffins also takes place, this reaction being of particular importance in the case of normal hexane as this hydrocarbon is of low octane rating and does not readily dehydrocyclicize Isomerization of normal hexane raises its octane rating significantly, and the present process provides for the selective recycle of unconverted normal hexane to the reaction zone with the raffinate stream in line 91, while removing the hexane isomers of high octane value as net products The important octane number increasing reaction of dehydrocyclization also occurs in reactor 27 By this reaction, a substantial portion of the paraffins is converted into aromatics This reaction is extremely important in increasing the octane number of the paraffins which are recycled to 70 the reforming reactor through line 91 The conditions in the reforming zone or reactor 27 are selected so that there are substantially no olefinic substances produced At the conditions hereinbefore specified and in the presence of 75 hydrogen and the catalyst described, olefinic materials will not be produced in any appreciable amounts. The effluent from reactor 27 passes through line 28, cooler 29, line 30, and into separator 80 31 Hydrogen is withdrawn from the top of receiver 31 through line 32 and is picked up by compressor 33 and discharged into line 34 and combines with the charge stream in line 26 and passes into furnace 94 Make-up hydro 85 gen may be added to the system through line 101 containing valve 102, or excess hydrogen may be withdrawn from the system through said line. The liquid hydrocarbons, comprising the 90 reformate and the bulk of

the normally gaseous hydrocarbons produced in the process, are withdrawn from receiver 31 through line 35 and passed into fractionator or stabilizer 36. Normally gaseous hydrocarbons are removed 95 overhead through line 37 In stabilizer 36 the normally gaseous material, which includes hydrogen, ammonia, hydrogen sulfide, and hydrocarbon gases containing from one to four carbon atoms per molecule, is separated from 100 the hydrocarbon liquid comprising aromatic hydrocarbons and paraffinic hydrocarbons. The gaseous material passes overhead through line 37 into cooler 38, wherein a portion of the material is condensed and the entire 105 stream passes through line 39 into receiver 40. In receiver 40 the liquid phase and the gaseous phase of the overhead material separate; the gaseous phase passes through line 42 from which it may be vented to the atmosphere or 110 used as fuel or else may be further used in the present process or other processes The stabi-lizer has heat provided thereto by reboiler 44 and connecting lines 43 and 45 The conditions in the stabilizer 36 may be such that the 115 gasoline therein is cut deeper, that is C, hydrocarbons may be removed through overhead line 37, however, in the usual operation only C 4 and lighter components are removed as overhead It is contemplated that the stabilizer and 120 receiver will operate at a sufficient pressure to liquefy at least a portion of the overhead material so that a liquid reflux stream may be available to improve the separation in stabilizer 36 The liquid reflux passes from receiver 40 125 through line 41 into the upper portion of stabilizer 36. The stabilizer bottoms, which comprise substantially paraffinic and aromatic hydrocarbons, are passed through line 46 into a 130 785,576 lower portion of extractor 47 In extractor 47 the hydrocarbon material rises and is countercurrently contacted at an elevated temperature in the liquid phase with a descending stream of a selective solvent In this embodiment, diethylene glycol is used, with the latter entering the upper portion of extractor 47 through line 48 Water may also be introduced into extractor 47 through line 70 which is shown as entering the top of extractor 47; however, the water may also be added to line 48 The water content of the diethylene glycol and water mixture is preferably about 7 5 % O XO The water is added to increase the selectivity of the solvent in line 48 As a result of the countercurrent contact of the selective solvent and the hydrocarbon charge to the extractor, the aromatic hydrocarbons contained in this charge are selectively dissolved in the solvent, thereby forming an extract stream containing the solvent and the bulk of the aromatic hydrocarbons, and a raffinate stream containing the bulk of the paraffinic hydrocarbons The raffinate stream passes from the upper

portion of extractor 47 through line 71 while the extract stream passes from the lower portion of extractor 47 through line 49 Line 49 passes to flashvaporization drum 50 Drum 50 is maintained at a pressure lower than the extractor and preferably is kept at about atmospheric pressure. In the flash-vaporization drum some of the light paraffinic components are flashed overhead and are removed through line 51 The remainder of the liquid is withdrawn from drum 50 through line 52 and is introduced to stripper 53 wherein the dissolved aromatic hydrocarbons and the minor quantities of dissolved paraffins are separated from the selective solvent Line 52 is preferably connected to the stripper 53 at a point in the upper half of the column The separation in stripper 53 is not difficult in that the aromatic hydrocarbons are substantially different in nature from the selective solvent and also have a substantially different boiling point The aromatic hydrocarbon stream along with some light paraffins passes overhead through line 54 and combines with the overhead from the flashvaporization drum in line 51 and the combined stream in line 55 may be passed to extract rectifier 56 Heat is provided for the stripping operation by reboiler 58 and connecting lines 57 and 59 The solvent stream is taken from the bottom of stripper 53 through line 48 and is passed into the upper portion of extractor 47. The combined stream in line 55 may be used as the final product; however, it may be subjected to further treatment in order to produce a product of higher quality In the present illustration the combined stream in line 55 is introduced to an intermediate portion of extract rectifier 56 In extract rectifier 56 the lighter components, chiefly the dissolved light paraffins, are removed overhead through line while the aromatics are removed through line 67 The gaseous material in line 60 passes through cooler 61 wherein the gaseous fraction is liquefied and from cooler 61 the fraction passes through line 62 into receiver 63 70 A portion of the liquefied overhead stream is passed through line 64 and line 65 into the upper portion of extract rectifier 56 as reflux, and a portion of the liquefied product is withdrawn from receiver 63 through line 64 and 75 66, which portion is introduced to the extractor 47 at a point in the lower half thereof. The rarinate stream from extractor 47 which is withdrawn through line 71 is further treated m order to improve its suitability for 80 recycling to the reforming reactor Tle raffinate contains dissolved or entrained solvent and further railinate contains components which may be heavier than are suitable tor reforming and the raffinate also contains paratlinic 85 components which are high enough in octane number and wnich may not be further improved by reforming. In the drawing the raffinate in line 71 is introduced into separator

72 Separator 72 may 90 be a type of holding tank wherein the solvent entrained in the raffinate is allowed to settle out of the raffinate phase Separated solvent is removed from separator 72 through line 73 and the remaining raffinate stream is with 95 drawn from separator 72 through line 74 and subjected to a water wash in vessel 75 Water wash column 75 is illustrated as a vertical vessel in which the raffinate is introduced at a lower portion thereof and is counter-currently 100 contacted with a descending stream of water introduced to coiumn 75 in the upper portion thereof through line 103 Water and solvent are removed from vessel 75 through line 76 and the washed raffinate is removed from the 105 upper portion of the vessel through line 77 and introduced to fractionator 78. In fractionator 78 the ratlinate is separated into a light overhead and into a heavier bottoms fraction which is recycled to the reform 110 ing zone The conditions in fractionator 78 are maintained so that components which are lighter than those which it is preferred to recycle to the reforming zone are removed as an overhead fraction In the embodiment of the 115 drawing the overhead is shown as comprising components boiling below normal hexane or from the boiling point of isohexane and lighter The column may be referred to as a deisohexanizer Components boiling from the 120 boiling point of isohexane and lighter are removed from deisohexanizer 78 through line 79 and pass into cooler 80 wherein the material is condensed and the entire stream passes through line 81 into receiver 83 The liquid in 125 receiver 83 is withdrawn through line 84 Line 84 splits up into several streams A portion of the stream in line 84 passes through line 85 into the upper portion of deisohexanizer 78 as reflux A portion of the liquid in line 84 may 130 -6 785,576 be withdrawn through line 82 as a product and in some instances may be combined with the product in line 67 A portion of the liquified stream in line 84, however, is withdrawn S through line 86 and passed to a lower portion of extractor 47 This use of the fraction containing isohtxanes and lighter materials in line 86, that is as reflux to extractor 47, is a preferred feature of the invention The use of this light fraction enables more of the heavier paraffins to be recycled to the reforming reactor and thus the combined operation provides a greater utilizing of the product streams and ultimately increases the yield and octane number of the final product Heat is provided for the deisohexanizer 78 by reboiler 88 and connecting line 87 and 90 The bottoms which are substantially free of components boiling below normal hexane are removed from deisohexanizer 78 through line 91 and may be directly introduced into the reforming reactor 27, after suitable heating; however, the drawing illustrates the preferred embodiment in which the heavy paraffins in line 91 are recycled to rerun column 15.

The drawing illustrates a preferred mode of carrying out the invention. A number of variations may be introduced into the process without departing from the spirit or scope of the invention; for example, the fresh gasoline charge and the raffinate recycle stream may be heated separately or in admixture with the hydrogen recycle stream. It may, with certain stocks, be advantageous to use a succession of several heaters and catalyst chambers in addition to the one shown.


* GB785577 (A)

Description: GB785577 (A) ? 1957-10-30

Photographic shutter


PATENT SPECIFICATION 785 577 Date of Application and filing Complete Specification: Jo 6 20, 1956. No 2070/56. Application made in Italy on Jan 22, 1955. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 40 ( 3), A 5 (M 1: R 4). International Classification:-GO 8 c. COMNIPLETE SPECIFICATION- Photographic Shutter We AGFA CAMRRA-WFRRK ATPMIW marlr tn xxrh;-h daha -1-11 _ of SPECIFICATION NO 785,577 By a direction given uinder Section 17 ( 1) of the Patents Act 1949 this application proceeded In the name of Agfa AY-tiengesellschaft, of Leverimsen-Bayerwerk, Germany, a company organised and existing under

the laws of the Federal Republic of Germany. TM PA 4 TEN OFFICE, 19th December, 2958 mechanism that can be brought into operation and disengaged as may be desired The disengagement of the automatic mechanism may be required for instance, when photographs are to be taken by flash-light. These known devices necessitate the provision of suitable supplementary control elements which serve the sole purpose of bringing the automatic shutter control mechanism into operation, or of disengaging the same, and these introduce complications in manipulation which lead to snapshots in particular being easily spoilt by some eror in the adjustment of the camera. To obviate these disadvantages the present invention therefore provides a photographic shutter capable of being manually set to various shutter speeds and incorporating a device for the automatic control of shutter speeds adapted to be optionally brought into engagement or dis-engaged by the manipulation of a member that also serves to set the shutter speed by hand. More particularly, there may be provided twvo alternatively operable shutter retarding mechanisms which can be brought into action by the manipulation of the same setting member. On the normal shutter speed scale the present invention provides an additional index lPrice DB 08927/1 ( 3)/3713 150 12/58 P. v W u tsU 47-f Lu' tiil C renluer inoperative the automatic shutter control mechanism Between the shutter setting member and the adapter which is coupled therewith there is further provided a coupling member which is inactive when the adapter is being moved into and out of the position that brings the automatic shutter control into and out of operation The adapter carries scale markings which indicate shutter speeds in conformity with the scale markings on the shutter speed setting member and also an additional reference mark for indicating that the automatic shutter control is in the operative position. According to the present invention the member which is used for setting the shutter speeds is provided with a cam which cooperates with a contact lever that causes the automatic shutter control to be brought into engagement or rendered inoperative. The device for automatically, controlling the shutter speed in an arrangement according to the present invention may incorporate, for instance, a pneumatic retarding mechanism, or it may, be electronically controlled. The present invention affords the advantage that the engagement and disengagement of the automatic shutter control device can be effected by a member which also serves to effect the manually controlled shutter settings. When the shutter speed setting member is PATENT SPECIFICATION

7859577 X Date of Application and filing Complete Specification: J 6 ts 20, 1956. No 2070 /56. Application made in Italy on Jan 22, 1955. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 40 ( 3), A 5 (M 1: R 4). International Classification:-GO 8 c. COMPLETE SPECIFICATION Photographic Shutter We, AGFA CAMERA-WERK Ax TIENGESELLSCHAFT, a body corporate recognised under German Law, of 161 Tegernseer Landstrasse, Munich '9, Germany, do hereby den clare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to 'be particularly described in and by the following statement:- This invention relates to a photographic shutter with an optionally operable automatic shutter speed control. Photographic cameras are already known which incorporate a shutter mechanism 'of conventional construction adapted for manual setting to various shutter speeds, and which also include an automatic shutter speed control' mechanism that can be brought into operation and disengaged as may be desired The 'disengagement of the automatic mechanism may be required, for instance, when photographs are to be taken by flash-light These known devices necessitate the provision of suitable supplementary control elements which serve the sole purpose of bringing the automatic shutter control mechanism into operation, or of disengaging the same, and these introduce complications in manipulation which lead to snapshots in particular being easily spoilt by some eror in the adjustment of the camera. To obviate these disadvantages the present invention therefore provides a photographic shutter capable of being manually set to various shutter speeds and incorporating a device for the automatic control of shutter speeds adapted to be optionally brought into engagement or dis -engaged by the manipulation of a member that also serves to set the shutter speed by hand. More particularly, there may be provided two alternatively operable shutter retarding mechanisms which can be brought into action by the manipulation of the same setting member. On the normal shutter speed scale the present invention provides an additional index lPrice mark to which the member for manually adjusting the shutter speed may be set for the purpose of bringing the automatic shutter speed control mechanism into operation. According to the present invention 'this mark is located on the speed setting member adiacent the normal shutter speed scale and next to, i e just beyond the mark on the scale that indicates the fastest shutter

speed The present invention may also be adapted to one of the conventional setting devices such as are only used for manually setting the shutter speeds as well as the R 3 and T shutter movements To this; end there is provided, for the purpose of actuating the setting member and coupled therewith, an adapter which also serves to bring into operation and render inoperative the automatic shutter control mechanism, Between the shutter setting member and the adapter which is coupled therewith there is further provided a coupling member which is inactive when the adapter is being moved into and out of the position that brings the automatic shutter control into and, out of operation The adapter carries scale markings which indicate shutter speeds in conformity with the scale markings on the shutter speed setting 'member and also an additional reference mark for indicating that the automatic shutter control is in the operative position. According to the present invention the member which is used for setting the shutter speeds is provided with a cam which cooperates with a contact lever that causes the automatic shutter control to be brought into engagement or rendered inoperative. The device for automatically controlling the shutter speed in an arrangement according to the present invention may incorporate, for instance, a pneumatic retarding mechanism, or it may be electronically controlled. The present invention affords the advantage that the engagement and disengagement of the automatic shutter control device can be effected by a member which also serves to effect the manually controlled shutter settings. When the shutter speed setting member is 2 785,577 moved to the index mark for automatic operation this ensures, in preferred forms of construction according to the present invention, that the mechanical retarding device incorpor) ated in the shutter is thereby also rendered inoperative Consequently, the possibility of faulty settings is positively removed. Two embodiments of the present invention are illustrated in the accompanying drawings in which: Fig 1 represents the shutter of a photographic camera with a pneumatic shutter control mechanism (see Specification No 4174/ 53) in the operative position, in front elevation, partly in section, Fig, 2 is the same device with the automatic control mechanism in the inoperative position, Fig 3 is an alternative embodiment shown in side elevation, Fig 4 is a front elevation of the embodiment illustrated in Fig 3, and Fig 5 shows a section taken through Fig. 3 along the line V-V and looking in the direction of the arrows. Referring to Figs 1 and 2 of the drawings the housing 1 of a lens shutter carries a ring 2 for setting the shutter speeds, a tensioning

lever 3, and a release lever 4 The shutter housing 1 contains a mechanical retarding device of usual construction, not shown, in the drawing, which causes the shutter to operate at the various speeds to which it is set For the purpose of setting the speeds the shutter setting ring 2 carries a speed scale 5 which can be adjusted to the fixed index -mark 6 on the housing Adjoining the speed scale 5 and next to the mark corresponding to the shortest exposure time, shown in the drawing at 1/500th second, there is a further mark 7 which can likewise be set to the fixed reference mark 6 by rotation of the setting ring. As will be hereinafter described in greater detail, this mark 7 serves to indicate that the automatic shutter speed control device is in operation and in the drawings it is therefore provided with the legend " AUTOM " Mounted on the rearnvard part, invisible in Figs 1 and 2, of the shutter housing 1 which projects through the setting ring 2 is a rigid arm 8 and on the outer extremity of this arm 8 a three-armed lever 10 is pivotally mounted so as to swing about a fulcrum 9 The arm 11 of -the lever 10 is linked to the piston rod 12 of the pneumatic retarding device (see Specification No 4174/53) controlled by an exposure meter, the device also comprising a cylinder 13, a piston 14, a photo-cell 15, a galvanometer 16, and a blade 18 attached to the spindle 17 of the galvanometer coil. The arm 19 of the lever 10 has a cam 20 for co-operation with the tensioning lever 3, whereas within the range of the third arm 21 of the lever 10 lies a two-armed lever 22 pivotally mounted at 23 on an arm 24 attached to the shutter housing 1 The lever 22 has a contact arm 25 which is urged by a spring 26 against the rim 27 of the speed setting ring 2 The rim 27 of the ring is provided with a peripheral cam 28 70 The described device operates as follows: If it is desired to use the automatic, pneumatic shutter speed regulating mechanism to control the shutter speed according to the brightness of the subject, with due regard to 75 the remaining factors affecting exposure time (such as aperture, sensitivity of the film), the speed setting ring 2 is rotated until the mark 7 aligns with the reference mark 6-as shown in Fig 1 In this position the mechanical 80 shutter retarding device in the housing 1 is disconnected and at the same time the contact arm 25 of the lever 22 lies in the cam depression 28 in the periphery of the speed setting ring 2 50 that the arm 21 of the lever 10 85 has freedom of movement Consequently the arm 19 of lever 10 is pulled by the spring 29 into contact with the lever 3 which is shown in Figs 1 and 2 in the tensioned position, in such a manner that the pneumatic 90 retarder is now able to act upon the shutter. When the speed setting ring 2 and the lever 3 are in the positions shown in Fig 1, the piston 14 of the pneumatic device is at the upper

end of its stroke within the cylinder 13 95 When the shutter release is operated, the lever 3 returns to the position shown in dotted outlines in Figs 1 and 2, under the action of a spring, not shown, located within the shutter housing 1 In performing this move 100 ment the lever 3 slides along the cammed edge 20 of the lever arm: 19 and forces the lever 10 to pivot in the clockwise direction against loading by a spring 29 and the retarding action of the pneumatic device which corm 105 prises the cylinder 13, the piston 14, the cylinder opening 30 and the galvanometer blade 18 Since the air opening 30 is obstructed by the blade 18 to an extent depending upon the photo-electric current developed by the cell 110 15, the return movement of the lever 3 is retarded to a greater or lesser extent and this retardation correspondingly affects the speed of the shutter. On the other hand, if it is desired to set 115 the shutter speed by hand, the shutter speed setting ring 2 is turned in the anti-clockwise direction to the appropriate setting on the speed scale 5 Owing to this rotation of the speed setting ring the contact arm 25 slides 120 on the cam 28 thus pivoting the lever 22 in an anti-clockwise direction so that it depresses the arm 21 of the lever 10 which is pivoted clockwise Hence the lever arm 19 is raised clear of the lever 3 in all positions of the 125 latter, as shown in Fig 2, and the entire pneumatically controlled shutter speed mechanisn is disengaged from the shutter When the shutter is now released it operates, without being affected by the pneumatic retarder, 130 785,5 '77 785, 77 3 according to the shutter speed that has been manually set. Figs 3 ' to 5 show another embodiment of the present invention adapted to be used in conjunction with a shutter mechanism of the conventional type Such a conventional shutter mechanism is illustrated more particularly in Fig 5, wherein structural elements which correspond with those already described, in connection with Figs 1 and 2 are indicated by the same reference numerals. The shutter mechanism illustrated in Fig. comprises within its housing 1 a mechanical retarding mechanism, not shown, and a speed setting ring 31 which carries a graduated scale for manually setting to the usual shutter speeds Since the rotation of this speed setting ring 3,1 is limited to the angle determined by the length of the scale 32 it cannot be used as a means for the engagement and disengagement of an automatic shutter control. Consequently, there is provided, mounted in front of the speed setting ring 31, an adapter ring 331, as shown in Fig 4, which in addition to a scale 34 which corresponds in all respects with the scale 32 on the setting ring 31, carries a further mark 35 for indicating the operative position of the automatic control. Moreover, the rim of this adapter ring 33 has a cam 3,6 which again

co-operates with a contact lever 22 ', 25 As described with reference to the embodiment shown in Figs. 1 and 2 the contact lever 22 controls the movement of a lever element which is: fulcrumed at 9 on the arm 18 ' and serves to bring into engagement or to disengage an automatic speed control which may again comprise a pneumatic retarding device The structural elements of the latter correspond with the analogous elements shown in Figs 1 and 2 but they have been omitted from Figs 3 ' to ' to avoid unnecessary repetition. The speed setting and' adapter rings 31 and 33 are coupled and for this purpose are provided with toothed segments 37 and 38 It may be expedient, instead of cutting the toothed segment 381 into 'the adapter ring 33, to cut the same into a supplementary ring 33 a which is rigidly connected with the adapter ring The toothed segments 37, 3:8 engage toothed wheels 39, 40 which are rigidly connected together and can rotate about a pin 43 on a bracket 42 attached to the housing. The toothed wheel 39 is also provided with a smooth segment 41 without teeth. The speed setting ring 31 can be set only by rotation of the adapter ring 33 ' which is coupled therewith through the toothed wheels 39 and 40, the two rings 313 and 31 being superimposed in such manner that the two speed scales 32 and, 34 are in exact alignment when the automatic control is not in operation so that similar marks on both scales always register with the fixed, reference mark 6 at the same time. If the adapter ring 33 is set to the shortest available exposure time (in the illustrated case 1/500th of a second), at which the mechanical retarder within the shutter housing is already disconnected, the smooth segment 70 41 ' lof the toothed wheel 39 will just have reached the toothed segment 37 of the speed setting ring 31 Consequently, the speed setting ring 31 remains stationary at the 1/500th setting while the adapter ring 33 can be fur 75 ther rotated to bring its mark 35 into alignment with the fixed reference mark 6, and thus the automatic control mechanism, not shown in the drawing, can 'be brought into engagement by way of the contact lever 22 in 80 the manner that has already been described with reference to Figs 1 and 2. Of course, the toothed wheel type of coupling between the setting ring 3; 1 and the -adapter ring 313 may be replaced by some other 85 type of coupling such as any well known type of friction coupling with an elastic intermediate member to allow for the differential setting ranges between the two rings 31 and 33 90 Moreover, an alternative automatic retarding device such as an electronic device can be used to replace the pneumatic retarder.