This document discusses pixels, LCD displays, LED displays, and compares LED and LCD displays. It provides information on: 1. How pixels are formed using a black matrix, red, green, and blue phosphors and aluminum layer. 2. LCD displays being the most mature flat panel technology but having poor viewing angles, requiring backlighting, and being inefficient. 3. How LEDs work by emitting photons when electrons fall to a lower energy level and the color is determined by the electron energy level.

1. Shree Swami Atmanand Sarswati
Institute of Technology
Subject :-Computer Aided Design(2161903)

2. INDEX
Sr No. Topics
1. Pixels
2. LCD
• Applications
3. LED
• How it works
• Inside LED
• Applications
4. LED Displays VS. LCD Displays

3. Pixels
Faceplate picture element
(pixels) are formed by
depositing and patterning
a black matrix, standard
red, green, and blue TV
phosphors and a thin
aluminum layer to reflect
colored light forward to
the viewer.

4. LCD
• Most mature flat panel
technology
• Major share of FPD market
• Poor intrinsic viewing angle
• Requires backlight
• Inefficient
• Slow
• Effected by Temperature and
sunlight

5. Applications:-
 Computer monitors
 Television
 Instrument panels
 Aircraft cockpit displays
 Gaming devices
 Video players
 Clocks and watches
 Calculators
 Mobiles
 Etc…

6. LED
 Light-emitting diode
 Semiconductor
 Has polarity

7. LED: How It Works
 When current flows
across a diode
 Negative electrons move one
way and positive holes move the
other way

8.  The wholes exist at a lower energy level than the free electrons
 Therefore when a free electrons falls it losses energy
 This energy is emitted in a form of a photon, which causes light
 The color of the light is determined by the fall of the electron
and hence energy level of the photon

9. Inside a Light Emitting Diode
1. Transparent Plastic
Case
2. Terminal Pins
3. Diode

10. Applications:-
 Traffic lights
 Televisions
 Camera flashes
 Automotive headlamps
 Medical devices

11. LED Displays VS. LCD Displays