Display Devices - Computer Monitors

Display Devices Computer MonitorsPrintersPlottersProjectorsMonitorsOther Displays

Display DevicesA display device is an output device for presentation of information in visual

or in tactile form

When the input information is supplied as an electrical signal, the display is called an electronic display

Display DevicesPrintersPlottersProjectorsMonitorsOther Displays

Segment DisplaysSome displays called segment displays can show only digits or alphanumeric characters. They are, because they are composed of several segments that switch on and off to give appearance of desired glyph. The segments are usually single LEDs or liquid crystals. They are mostly used in digital watches and pocket calculators.

Seven-segment display: most common, usually digits onlyFourteen-segment displaySixteen-segment displayHD44780 LCD controller: a widely accepted protocol for LCDs.

2D Displays2-dimensional displays that cover a full area (usually a rectangle) are also called video displays, since it's the main modality of presenting video.

Full-area 2-dimensional displays are used in, for example:

Television setsComputer monitorsHead-mounted displayBroadcast reference monitorMedical monitors

2D Display TechnologiesCathode ray tube display (CRT)Electronic paper, E InkPlasma display panel (PDP)Liquid crystal display (LCD) Light-emitting diode display (LED)Organic light-emitting diode display (OLED)Laser Display (forthcoming)

Electronic paper, E Ink

3D DisplaysSwept-volume displayVarifocal mirror displayEmissive volume displayLaser displayHolographic displayLight field displays

Further information: Volumetric displayStereoscopy

Stereo Displays

Stereo displays

Anaglyph 3DPolarized 3DActive Shutter 3D

Anaglyph 3DAnaglyph 3DAnaglyph 3D is the name given to the stereoscopic 3D effect achieved by means of encoding each eye's image using filters of different (usually chromatically opposite) colors, typically red and cyanAnd old technology and usually the 3d quality is not good, and color quality is poorScreen independent, any display can be used

Anaglyph 3D

Polarized 3DPolarized 3D

A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye

Polarized 3D

iZ3D

Active Shutter 3DActive Shutter 3DAn active shutter 3D system (AKA: alternate frame sequencing, alternate image, AI, alternating field, field sequential or eclipse method) is a technique of displaying stereoscopic 3D images, works by openly presenting the image intended for the left eye while blocking the right eye's view, then presenting the right-eye image while blocking the left eye, at a speed high enough to not be perceived by human sight, thus allowing the images to be perceived as fused into a single 3D imageActive shutter 3D systems generally use liquid crystal shutter glasses

Active Shutter 3D

Active vs PassiveActive 3D GlassesActive Shutter

Passive 3D GlassesAnaglyphPolarized

Active vs Passive: Comparison http://www.ebay.com/gds/Whats-the-Difference-Between-Active-and-Passive-3D-TV-Glasses/26040/g.html

Monitors

CRTLCDOLED

ConnectorsVGA (D-sub)Analog. CommonS-VideoAnalog. SD videoDVIDigital. HD videoHDMIDigital. HD video and audioDisplayPortHigh/Cross Compatibility. Latest Trend

CRT MonitorsCRT: Cathode Ray Tube

Plasma DisplaysUsually used in TVsUtilizes small cells containing electrically charged ionized gases, or what are in essence chambers more commonly known as fluorescent lamps

LCD MonitorsLCD: Liquid Crystal Display

Passive MatrixActive MatrixTFT LCD

TFT-LCDTFT: Thin Film Transistor

TFT LCD Panel Types

TN: Twisted NematicIPS: In-Plane SwitchingVA: Vertical Alignment

TNTN: Twisted Nematic

Most common technology and also the oldest. Short response timesHigh brightnessLess power consumptionLow cost

Color shifts, especially at wider viewing anglesNo true color (24bit) support. Only 18bit (6bit per channel instead of 8). Therefore unable to display the 16.7 million colorsDisplay interpolated 24bit color using a dithering method that combines adjacent pixels to simulate the desired shade

IPS

IPS: In-Plane Switching

Wide viewing angleAccurate colors

High cost

TN, VA, IPSTN vs IPS vs VAhttp://www.tnpanel.com/tn-vs-ips-va/

TN vs VA vs IPShttp://asia.cnet.com/lcd-types-tn-vs-va-vs-ips-62213690.htm

LCD Panel TestsOnline LCD Monitor Panel Type Evaluatorhttp://www.mediachance.com/pbrush/monitor.html

The Lagom LCD monitor test pageshttp://www.lagom.nl/lcd-test/

BacklightA backlight is a form of illumination used in LCDs. As LCDs do not produce light themselves (unlike CRTs), they need illumination (ambient light or a special light source) to produce a visible image

Common Light SourcesCCFL: Cold Cathode Fluorescent LampLED: Light Emitting Diode

Early TFT-LCD monitors used a CCFL backlit and modern ones usually comes with a LED backlit. Therefore they are called LED monitors. Those LED monitors are LCD monitors (with LED backlight)

BacklightCCFL vs LEDhttp://www.wikivs.com/wiki/CCFL_backlight_vs_LED_backlighthttp://www.screentekinc.com/backlight-ccfl-led-explained.shtml

CCFLLEDSizeThicker and HeavierThinner and LighterCostCheaperExpensive (slightly), but affordablePowerHigher Power consumption & Heat generationLower Power consumption and Heat generationBrightnessLower brightnessGenerally higher brightnessLifespanShorter lifespanLonger lifespan

Issues with LCD monitorsDefective Pixels

Hot PixelPixel Always OnWhite

Dead PixelPixel Always OffBlack

Stuck Pixel1 or 2 sub-pixels Always On or OffDisplay inaccurate colors

Check Defective PixelsCan be done manually changing background colorsOr using softwareOr Online

Online Defective Pixel Testshttp://mydeadpixeltest.comhttp://www.checkpixels.comhttp://www.gdargaud.net/Hack/DeadPixels.html

CRT vs LCDCRTBest Color QualityFaster Response Time (0)True BlackMultiple Frequency supportMulti Sync, Multi-ResolutionLower Cost

Higher Power ConsumptionHigher Heat generationHigher RadiationHigher SpaceHigher Weight

LCDNot as good as CRTResponse time usually >=5msCan not display true blackPoor multi-frequency supportPoor quality in non-native resolutionsHigher Cost

Lower Power ConsumptionLower Heat generationLower RadiationLower SpaceLower Weight

http://bootstrike.com/Articles/LCDvsCRT/http://compreviews.about.com/od/multimedia/a/CRTvsLCD.htmhttp://en.wikipedia.org/wiki/Comparison_of_CRT,_LCD,_Plasma,_and_OLED

OLEDOLED: Organic Light-Emitting DiodeAn OLED is a LED in which the emissive electroluminescent layer is a film of organic compoundAn OLED display works without a backlight. Thus, it can display deep black levels and can be thinner and lighter than a LCD. In low ambient light conditions such as a dark room an OLED screen can achieve a higher contrast ratio than an LCD

AMOLED: Active Matrix OLEDA display technology for use in mobile devices and televisions

OLED vs LCD

OLED vs LCD

Power ConsumptionImportantCRT displays consume low power when displaying Black/Dark colorsLCD displays (both CCFL and LED backlit) consume low power when displaying White/Light colorsOLED displays consume low power when displaying Black/Dark colors

35

Power ConsumptionGenerally, displays with a backlight need high power to display black/dark colors. Less power to display white. Backlight is always on and white is the default color. LCD have to block the white light to display other colors, and it takes some extra power. To display black, about 3% more power needed (a little more). Displays that do not use a backlight consume least power to display black and full power to display white. In those displays, the difference is significant and it is/was encouraged to use darker backgrounds as possibleSome Few New LCD displays use some advanced technologies (such as zone control, changing the backlight brightness accordingly to the colors displayed) and they may consume little lesser power to display black.

Power ConsumptionTipsGenerally, Old CRTs and Future OLEDs are better with dark colors. Currently most displays are LCD and therefore the color does not matter much. Even though Lighter colors save some power, other factors such as eye strain etc. favor darker colors. Anyway, it is always better to Reduce the Display Brightness and it ALWAYS saves power, as it does reduce the color of the backlight. Also it is good for eyes. Do not reduce brightness too much and also do not reduce the Contrast. Usually reducing contrast does nothing good.In LCD, Blank or Dark Screensavers are not power savers. But Turn off the display feature is a huge power-saver as it does turn off both Monitor and Graphic Processing (VGA/GPU switched off)

Thank You!Ayubowan!