COLOR IN DISPLAYS

WOO SUB SHIM TC 706 COLOR SCIENCE

ADVISOR: DR. RENZO SHAMEY OCTOBER 28 2008

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Development of Displays

www.eliatech.com/img/display1.gif

Cathode Ray Tube (CRT) Construction for Monochrome (Gray)

Colour Physics for Industry, ed. R. McDonald, p.374, 1997

CRT Construction for Multichrome (Color)

The four types of shadow mask geometry in color CRTs

Delta (a), (b)

Linear (c), (d)

Colour Physics for Industry, ed. R. McDonald, p.378, 1997

Merging Color

www.colorado.edu/.../tv/images/rgbScreenComp.jpg

Spectra characteristics of phosphors

P22:

(ZnS:Cu)

(ZnS:Ag)

http://www.reprise.com/host/tektronix/reference/phosphor1.asp

Blue Green

Red

Chromaticity coordinates

Colour Physics for Industry, ed. R. McDonald, p.384, 1997

Arrangement of Phosphor Dots

www.kdaq.empas.com

Dots Pitch

www.megapixel.net

Liquid Crystal Display (LCD)

Layer-like Thread-like Helical-like

Three common phases of liquid crystal materials

Colour Physics for Industry, ed. R. McDonald, p.389, 1997

Twisted Nematic LC Cell for Monochrome (Gray)

Colour Physics for Industry, ed. R. McDonald, p.391, 1997

Twisted Nematic LC Cell for Multichrome (Color)

www.cmo.com.tw/.../UploadImages/tft_lcd-2.gif

How LCD Panel Can Produce Colors

www.plasma.com/.../images/Generating_Colors.jpg

Thin Film Transistor (TFT) Array

(the form of illuminant)

OLED Components

Substrate (clear plastic, glass, foil) Anode (transparent) - removes electrons Conducting layer - made of organic plastic molecules Emissive layer - made of organic plastic molecules Cathode - injects electrons

http://electronics.howstuffworks.com/oled1.htm

How do OLEDs Emit Light? • Applied voltage across the OLED • Electrons find electron holes

• The OLED emits light. • The color of the light depends on the type of organic molecule in the emissive layer. Manufacturers place several types of organic films on the same OLED to make color displays. • The intensity or brightness of the light depends on the amount of electrical current applied: the more current, the brighter the light.

http://electronics.howstuffworks.com/oled1.htm

What is Gamut?

color gamut graph of a typical CRT monitor

www.cmpg.org/site/2005/07/26/an-introduction-to-color-space-and-color-calibration/

Comparison of Color Gamut

D

Lab Space

Typical CRT monitor

Typical LCD monitor

Inkjet printer

Reproduced from www.dhark.com/images/color_gamut.jpg

Gamut Mapping

- re-defining the colors of a given device - an important problem in color management

www.people.csail.mit.edu/.../img/01-gamutplots.jpg

References 1. www.eliatech.com/img/display1.gif

2. Colour Physics for Industry, ed. R. McDonald, Society of Dyes and Colourist, 2nd edition, 1997

3. www.colorado.edu/physics/2000/tv/colortv.html

4. www.computer.howstuffworks.com/monitor.htm/printable

5. http://www.cmpg.org/site/2005/07/26/an-introduction-to-color-space-and-color-calibration/

6. http://www.reprise.com/host/tektronix/reference/phosphor1.asp

7. Hawkyard C J (1991), Colour in Visual Display, Rev Prog Color, 21, 43-55

8. Sargeant C (2002), Colour Display Systems, Rev Prog Color, 32, 58-62

9. http://electronics.howstuffworks.com/oled1.htm

10. www.people.csail.mit.edu/.../img/01-gamutplots.jpg

“I think you should be more explicit here in step 2.”

Questions?