LCD screen

Making Colored Pictures

Output: Screen Features

The device which displays computer output to us has various names:

Screen	from "computer screen" or "display screen"
Monitor	from its use as a way to "monitor" the progress of a program
VDT	= video display terminal from early network terminals
CRT	= cathode ray tube from the physical mechanism used for the screen.
VDU	= visual display unit to cover all the mechanisms from desktop CRTs to LCD flat screens on laptops to LED screen on palmtops

LCD (Liquid Crystal Display) screen is very flat and thin. LCD displays are made of two layers of a polarizing material with a liquid crystal solution in between, divided into tiny cells. An electrical signal to a cell makes the crystals line up in a way that keeps light from going through entirely or just partly. When the screen is black, all the crystals lined up so that no light gets through.

To make color an LCD screen uses 3 colored subcells for each cell: R ed, G reen, and B lue. This RGB system can create all the other colors by combining how much of each of these colors you see.The signal for a picture cleverly light ups just the right subcells in just the right strengths to show the desired color. Your eye blends the colors in the cells together and you see a picture.

LCD screens used to be hard to see unless you were directly in front of the screen. Recent developments have fixed this issue.

CRT screen:

Old Type: A CRT monitor screen uses a cathode ray tube. The screen is coated on the inside surface with dots of chemicals called phosphors. When a beam of electrons hits a dot, the dot will glow.

On a color monitor these phosphor dots are in groups of three:
R ed, G reen, and B lue. This RGB system can create all the other colors by combining what dots are aglow.

Дата добавления: 2014-12-23