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1. INTRODUCTION

Todays electronic displays have ever more evolved to be more lightweight, efficient

and clear. Yet the importance of the paper has not diminished. We still prefer it to others for a

variety of reasons including its readability, high contrast, convenient handling, minimum

power requirement cost and strain less reading it offers. At the same time, an electronic

display offers us a paperless environment and relieves us from carrying loads of paper for

referring to information when required.

Electronic ink is a pioneering invention that combines all the desired features of a

modern electronic display and the sheer convenience and physical versatility of sheet of

paper. E-paper or electronic paper is sometimes called radio paper or smart paper. Paper

would be perfect except for one obvious thing: printed words can’t change. The effort is to

create a dynamic high-resolution electronic display that’s thin and flexible enough to become

the next generation of paper.

The technology has been identified and develop ed is well under way. Within five

years, it is envisioned electronic books that can display volumes of information as easily as

flipping a page and permanent newspapers that update themselves daily via wireless

broadcast. They deliver the readability of paper under virtually any condition, without back

lighting. And electronic ink displays are persistent without power, drawing current only when

they change, which means batteries can be smaller and last longer.

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1.1 History

Electronic paper was first developed in the 1970s by Nick Sheridan at Xerox’s Palo

Alto Research center. The first electronic paper, called Gyricon, consisted of tiny, statically

charged balls that were black on one side and white on the other. The "text" of the paper was

altered by the presence of an electric field, which turned the balls up or down. In the 1990s

another type of electronic paper was invented by Joseph Jacobson, who later co- founded the

corporation E Ink which formed a partnership with Philips Components two years later to

develop and market the technology

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2. TECHNOLOGY USED

2.1 Gyricon

Electronic paper was first developed in the 1970s by Nick Sheridon at Xerox's Palo

Alto Research Center. The first electronic paper, called Gyricon, consisted of polyethylene

spheres between 75 and 106 micrometers across. Each sphere is a Janus particle composed of

negatively charged black plastic on one side and positively charged white plastic on the

other(each bead is thus a dipole). The spheres are embedded in a transparent silicone sheet,

with each sphere suspended in a bubble of oil so that they can rotate freely. The polarity of

the voltage applied to each pair of electrodes then determines whether the white or black side

is face-up, thus giving the pixel a white or black appearance. At the FPD 2008 exhibition,

Japanese company Soken has demonstrated a wall with electronic wall-paper using this

technology

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2.2 Electrophoretic

An electrophoretic display forms visible images by rearranging charged pigment particles

using an applied electric field.

In the simplest implementation of an electrophoretic display, titanium dioxide particles

approximately one micrometer in diameter are dispersed in a hydrocarbon oil. A dark-colored

dye is also added to the oil, along with surfactants and charging agents that cause the particles

to take on an electric charge. This mixture is placed between two parallel, conductive plates

separated by a gap of 10 to 100 micrometers. When a voltage is applied across the two plates,

the particles will migrate electrophoretic ally to the plate bearing the opposite charge from

that on the particles.

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When the particles are located at the front (viewing) side of the display, it appears

white, because light is scattered back to the viewer by the high- index titanium particles.

When the particles are located at the rear side of the display, it appears dark, because the

incident light is absorbed by the colored dye. If the rear electrode is divided into a number of

small picture elements (pixels), then an image can be formed by applying the appropriate

voltage to each region of the display to create a pattern of reflecting and absorbing regions.

Electrophoretic displays are considered prime examples of the electronic paper

category, because of their paper- like appearance and low power consumption.

Electrophoretic displays can be manufactured using the Electronics on Plastic by Laser

Release (EPLaR) process developed by Philips Research to enable existing AM-LCD (Active

matrix liquid crystal display) manufacturing plants to create flexible plastic displays.

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2.2.1 Electronics on Plastic by Laser Release (EPLaR)

Electronics on Plastic by Laser Release (EPLaR) is a method for manufacturing

flexible electrophoretic display using conventional AM-LCD manufacturing equipment

avoiding the need to build new factories. The technology can also be used to manufacture

flexible OLED (Organic LED) displays using standard OLED fabrication facilities.

The technology was developed by Philips Research and uses standard display glass as

used in TFT-LCD processing plants. It is coated with a layer of polyimide using a standard

spin-coating procedure used in the production of AM-LCD displays. This polyamide coating

can now have a regular TFT matrix formed on top of it in a standard TFT processing plant to

form the plastic display, which can then be removed using a laser to finish the display and the

glass reused thus lowering the total cost of manufacture.

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2.2.2 Development in Electrophoretic Display:

In the 1990s another type of electronic paper was invented by Joseph Jacobson, who later co-

founded the E Ink Corporation which formed a partnership with Philips Components two

years later to develop and market the technology. In 2005, Philips sold the electronic paper

business as well as its related patents to Prime View International. This used tiny

microcapsules filled with electrically charged white particles suspended in colored oil. In

early versions, the underlying circuitry controlled whether the white particles were at the top

of the capsule (so it looked white to the viewer) or at the bottom of the capsule (so the viewer

saw the color of the oil). This was essentially a reintroduction of the wellknown

electrophoretic display technology, but the use of microcapsules allowed the display to be

used on flexible plastic sheets instead of glass.

One early version of electronic paper consists of a sheet of very small transparent

capsules, each about 40 micrometers across. Each capsule contains an oily solution

containing black dye (the electronic ink), with numerous white titanium dioxide particles

suspended within.

The particles are slightly negatively charged, and each one is naturally white. The

microcapsules are held in a layer of liquid polymer, sandwiched between two arrays of

electrodes, the upper of which is made transparent.

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The two arrays are aligned so that the sheet is divided into pixels, which each pixel

corresponding to a pair of electrodes situated either side of the sheet. The sheet is laminated

with transparent plastic for protection, resulting in an overall thickness of 80 micrometers, or

twice that of ordinary paper.

The network of electrodes is connected to display circuitry, which turns the electronic

ink 'on' and 'off' at specific pixels by applying a voltage to specific pairs of electrodes.

Applying a negative charge to the surface electrode repels the particles to the bottom of local

capsules, forcing the black dye to the surface and giving the pixel a black appearance.

Reversing the voltage has the opposite effect - the particles are forced from the surface,

giving the pixel a white appearance. A more recent incarnation of this concept requires only

one layer of electrodes beneath the microcapsules.

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2.3 Electrowetting

Electro-wetting display (EWD) is based on controlling the shape of a confined water/oil

interface by an applied voltage. With no voltage applied, the (coloured) oil forms a flat film

between the water and a hydrophobic (water-repellent), insulating coating of an electrode,

resulting in a colored pixel.

When a voltage is applied between the electrode and the water, the interfacial tension

between the water and the coating changes. As a result the stacked state is no longer stable,

causing the water to move the oil aside.

This results in a partly transparent pixel, or, in case a reflective white surface is used

under the switchable element, a white pixel. Because of the small size of the pixel, the user

only experiences the average reflection, which means that a high-brightness, high-contrast

switchable element is obtained, which forms the basis of the reflective display.

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Displays based on electro-wetting have several attractive features. The switching

between white and colored reflection is fast enough to display video content.

It is a low-power and low-voltage technology, and displays based on the effect can be

made flat and thin. The reflectivity and contrast are better or equal to those of other reflective

display types and are approaching those of paper. In addition, the technology offers a unique

path toward high-brightness full-color displays, leading to displays that are four times

brighter than reflective LCDs and twice as bright as other emerging technologies.

Instead of using red, green and blue (RGB) filters or alternating segments of the three

primary colors, which effectively result in only one third of the display reflecting light in the

desired color, electro-wetting allows for a system in which one sub-pixel is able to switch two

different colors independently. This results in the availability of two thirds of the display area

to reflect light in any desired color. This is achieved by building up a pixel with a stack of

two independently controllable colored oil films plus a color filter.

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2.4 Electrofluidic

Electrofluidic displays are a variation of an electro wetting display. Electro fluidic displays

place an aqueous pigment dispersion inside a tiny reservoir. The reservoir comprises <5-10%

of the viewable pixel area and therefore the pigment is substantially hidden from view.

Voltage is used to electromechanically pull the pigment out of the reservoir and spread it as a

film directly behind the viewing substrate. As a result, the display takes on color and

brightness similar to that of conventional pigments printed on paper. When voltage is

removed liquid surface tension causes the pigment dispersion to rapidly recoil into the

reservoir. As reported in the May 2009 Issue of Nature Photonics, the technology can

potentially provide >85% white state reflectance for electronic paper.

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3. KEY BENEFITS

E-Paper has numerous benefits. The reader does not need to get used to a new format-

reading an E-Paper equals reading a printed newspaper. However, E-Paper guarantees in

dependency regarding room and time. E-Paper can be read everywhere in the world, at every

hour, and since digital editions can also be received on PDAs and smart phones, mobility is

almost limitless. Additionally, E-Paper saves resources. On the one hand, paper and space are

saved - because E-Paper does not pile up anywhere - on the other hand, valuable time is

saved. Since the complete pages are displayed on the PC monitor, one instantly gets an

overview over all headlines and thus gets to the relevant articles a lot faster Unlike

conventional LCDs and other kinds of reflective displays, an electronic ink display is

exceptionally bright and is ready viewable under both bright and dim lighting conditions. To

be more assertive we could compare electronic ink display with the latest liquid crystal

displays.

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Table 3.1: Comparison of E- ink & LCD

3.1 Paper-like Readability

Paper is easily readable over wide variations in lighting conditions and viewing angle .E Inks

electronic ink technology approaches printed paper in performance by incorporating the same

coloring pigments often used to make paper white and ink black.

When reading text, both reflectance and contrast are important factors in determining

the readability of a display. In fact, the contrast of E Ink is nearly twice that of printed

newspaper. As can be seen from its high reflectance and contrast the E Ink display is much

more readable than LCD.

The bright paper-white background of electronic ink eliminates the need for a

backlight is most conditions.

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3.2 Ultra-Low Power Consumption

Electronic ink displays offer greatly reduced power consumption. Lower power

consumption translates to longer battery life, and perhaps more importantly, the ability to use

smaller batteries in electronic ink devices- reducing device weight and cost. The reason for

the reduced power consumption offered by electronic ink displays is two- fold: (1) they are

completely reflective requiring no backlight and (2) they are inherently bi-stable for extended

periods of time. Once an image is written on an electronic ink display, it will be retained

without additional power input until the next image is written. Hence the power consumption

of an electronic ink display will ultimately depend upon the frequency at which the displayed

image is changed. However, in both cases, a reduction in power consumption by several

orders of magnitude can be achieved by using electronic ink with its bi-stable imaging.

3.3 Thin, Light Form Factor

An electronic ink display module is thinner, lighter weight, and more robust than

conventional LCDs. These benefits are especially important in smart handheld applications

where portability is paramount. First generation, electronic ink displays will be b ut by

laminating electronic ink to a conventional glass TFT substrate In addition, no polarizes are

required for electronic ink displays. The resulting electronic ink display cell is also about half

that of a typical LCD cell. Elimination of the glass top sheet means that displays made within

electronic ink display module should be inherently more robust.

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3.4 The Ultimate Mobile Display Solution

Paper-like viewing characteristics and appearance, combined with ultra- low power

consumption and thin light form factors, make E inks electronic ink display material the ideal

technology solution for information intensive, handheld devices such as PDAs, mobile

phones and electronic readers; or any applications requiring a high degree of displayegibility.

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3.5 Twistable

Electronic Paper is made using soft plastic containing small particles and fluid. As there is no

hard material, Electronic Paper is highly flexible and it is able to be twisted orb ended into

different curvatures. The Electronic Paper can be applied to different shapes of products,

without being limited to being bonded to flat display panels. The end product becomes more

imaginative in shape and style.

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3.6 Simple Manufacturing Process

The manufacturing process is carried out using a roll- to-roll method, similar to printing

paper, by injecting dielectric fluid and charged particles into the layer of capsules, and then

sealing the top layer. The production is performed continuously at high speed. The Electronic

Paper can be produced in a large form and then cut into any desired size and shape for

different application requirements.

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4. HIGHLIGHTS OF ELECTRONIC INK

Electronic ink moves information display to a new dynamic level, with dramatic benefits over

traditional media.

Superior Look - Because its made from the same basic materials as regular ink and

paper, electronic ink retains the superior viewing characteristics of paper, including

high contrast, wide viewing angle, and bright paper-white background.

Versatile - Electronic ink can be printed on almost any surface, from plastic to metal

to paper. And it can be coated over large areas cheaply.

Low Power - Electronic ink is a real power miser. It displays an image even when the

power is turned off and its even legible in low light reducing the need for a backlight.

This can significantly extend battery life for portable devices.

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Scalable - E Inks electronic ink process is highly scalable, which makes it

competitive against todays older technologies

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5. DISADVANTAGES

Electronic paper technologies have a very low refresh rate comparing with other low-

power display technologies, such as LCD. This prevents producers from implementing

sophisticated interactive applications (using fast moving menus, mouse pointers or scroll

ing) like those which are possible on handheld computers. An example of this limitation

is that document cannot be smoothly zoomed without either extreme blurring during the

transition or a very slow zoom.

Another limitation is that an imprint of an image may be visible after refreshing parts

of the screen. Those imprints are known as "ghost images", and the effect is known as

“ghosting". This effect is reminiscent of screen burn- in but, unlike it, is solved after the

screen is refreshed several times. Turning every pixel white, then black, then white, helps

normalize the contrast of the pixels. This is why several devices with this technology

"flash “the entire screen white and black when loading a new image, in order to prevent

ghosting from happening.

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6. APPLICATIONS

Electronic Paper behaves similarly to conventional paper, a lowing high readability under

low or high light conditions, and being thin and lightweight and fully pliable. In addition,

Electronic Paper has the advantage of allowing the content to be changed easily at any

time via the Electronic Paper driver IC. Electronic Paper will provide a viable substitute

to paper in certain areas. Some examples of Electronic Paper applications are described

below.

6.1 Electronic Shelf Label

In a large department store or supermarket, there are many price tag labels on the shelves

indicating product price. Whenever there is a change of price information, it is very

tedious to change the price tags individually. By replacing the paper price tag with

Electronic Paper, the price information can be easily updated once the Electronic Paper

price tags are connected via a wireless network.

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The Electronic Paper price tag requires no battery power to maintain display and prices

can be updated using the energy from the RF wave to change the image content.

6.2 Electronic Watch and Clock

Watch and clock designs can become more imaginative using Electronic Paper.

For example, a watch using Electronic Paper will allow time and image to be displayed

on the wrist strap of the watch.

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6.3 e-Books

In 2004 Sony released Librium EBR-1000EP in Japan, the first e-book reader with an

electronic paper display. In November 2006, the iRex iLiad was ready for the consumer

market. In November 2009 Barnes and Noble launched the Barnes & Noble Nook, based

on the Android operating system.

In late 2007, Amazon began producing and marketing the Amazon Kindle, an e-book

reader with an e-paper display.

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Fig - 6.3: Sony E- book reader

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6.4 Smart Card Display

Today, many credit cards contain a smart card to store information such as

accumulated credit and money expenses etc. Since Electronic Paper has the advantage of

lower power consumption and is as flexible as the card, it offers a good solution to displaying

this type of information on the card.

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6.5 Newspapers

In February 2006, the Flemish daily De Tied distributed an electronic version of the

paper to select subscribers in a limited marketing study, using a pre-release version of the ire

Iliad. This was the first recorded application of electronic ink to newspaper publishing. In

September 2007, the French daily Les Echo’s announced the official launch of an electronic

version of the paper on a subscription basis.

Since January 2008, the Dutch daily NRC Handelsblad is distributed for the

iRexiLiad reader

Fig-6.4: Electronic newspaper

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6.6 Other Products

E- Ink unveiled its first product using electronic ink- immediate large-area displays- in1999.

These large signs draw only 0.1 watts of power, which means that the same power required

running a single 100-watt light bulb, could power 1,000 immediate signs. E Ink said that in

electronic devices, electronic ink would use 50 to 100 times power than liquid crystal

displays because electronic ink only needs power when changing its display. Electronic ink

can be printed on any surface, including walls, billboards, product labels and T-shirts.

Homeowners could soon be able to instantly change their digital wallpaper by sending a

signal to the electronic ink painted on their walls.

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7. The Future Scenario

The Holy Grail of electronic ink technology is a digital book that can typeset itself and that

readers could leaf through just as if it were made of regular paper. Such a book could be

programmed to display the text from a literary work and once you’ve finished that tale, you

could automatically replace it by wirelessly downloading the latest book from a computer

database.

Xerox had introduced plants to insert a memory device into the spine of the book,

which would allow users to alternate between up to 10 books stored on the device. Just as

electronic ink could radically change the way we read books, it could change the way you

receive your daily newspaper.

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It could very well bring an end to newspaper delivery, as we know it. Instead of

delivery people tossing the paper from their bike or out their car window, a new high- tech

breed of paper deliverers who simply press a button on their computer that would

simultaneously update thousands of electronic newspapers each morning. Sure, it would look

and feel like your old paper, but you wouldn’t have to worry about the newsprint getting

smudged on your fingers, and it would also eliminate the piles of old newspapers that need

recycling. Prior to developing digital books and newspapers E-Ink will be developing a

marketable electronic display screen for cell phones, PDAs, pagers and digital watches.

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8. Conclusion

The Holy Grail of electronic ink technology is a digital book that can typeset itself and that

readers could leaf through just as if it were made of regular paper. Such a book could be

programmed to display the text from a literary work and once you've finished that tale, you

could automatically replace it by wirelessly downloading the latest book from a computer

database. Xerox had introduced plants to insert a memory device into the spine of the book,

which would allow users to alternate between up to 10 books stored on the device. Just as

electronic ink could radically change the way we read books, it could change the way you

receive your daily newspaper.

It could very well bring an end to newspaper delivery, as we know it. Instead of

delivery people tossing the paper from their bike or out their car window, a new high- tech

breed of paper deliverers who simply press a button on their computer that would

simultaneously update thousands of electronic newspapers each morning. Sure, it would look

and feel like your old paper, but you wouldn't have to worry about the newsprint getting

smudged on your fingers, and it would also eliminate the piles of old newspapers that need

recycling. Prior to developing digital books and newspapers E-Ink will be developing a

marketable electronic display screen for cell phones, PDA's, pagers and digital watches.

Electronic ink is not intended to diminish or do away with traditional displays. Instead

electronic ink will initially co-exist with traditional paper and other display technologies. In

the long run, electronic ink may have a multibillion-dollar impact on the publishing industry.

Ultimately electronic ink will permit almost any surface to become a display, bringing

information out of the confines of traditional devices and into the world around us.

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REFERENCE

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Journalof Electrostatics 2002, 55, (3-4), 247.[2] Comiskey, B.; Albert, J. D.; Yoshizawa, H.;

Jacobson, J. "An electrophoretic ink for all-printed reflective electronic displays" Nature

1998, 394, (6690), 253-255.[3] http://en.wikipedia.org/wiki/Electronic_paper.[4]

Blankenbach K, Schmoll A, Bitman A, Bartels F and Jero sch D 2008 Novel highlyreflective

and bistable electrowetting displays SID J. 16 237–44.[5] Andersson, P.; Nilsson, D.;

Svensson, P. O.; Chen, M.; Malmström, A.; Remonen, T.;Kugler, T.; Berggren, M. "Active

Matrix Displays Based on All-Organic ElectrochemicalSmart Pixels Printed on Paper" Adv

Mater 2002, 14, (20), 1460-1464.[6] Huitema, H. E. A.; Gelinck, G. H.; van der Putten, J. B.

P. H.; Kuijk, K. E.; Hart, C. M.;Cantatore, E.; Herwig, P. T.; van Breemen, A. J. J. M.; de

Leeuw, D. M. "Plastic transistorsin active-matrix displays" Nature 2001, 414, (6864), 599

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