Since the beginning of this century, LCDs have pushed out the bulky CRT monitors from both computer and TV markets. The term LCD encompasses a wide variety of technologies, and many of these are still being developed further. Hardware.Info dives into the world of displays, analysing current and future technologies.
E-ink (see further down), a more recent technology.
Liquid Crystal Displays, or LCDs, exist in many variations. LCD technology is used in everything from wrist watches and calculators to 70-inch and larger TVs. While all of these utilise liquid crystals, there are significant differences in how they are assembled and controlled.
Light and colour on LCD screens
The different types of LCD screens have one thing in common - the liquid crystals do not produce light on their own. Like a sort of minuscule window blinds, they can either block light or let it through. In colour monitors each pixel consists of (usually three) subpixels, that are also able to give the light colour. In most cases that is red, green, and blue.
Behind the screen is a light source. The pixels control the amount of light that gets through, creating differences in brightness. When the image needs to be white, the pixel lets all the light pass. If it needs to be black, the pixel will block all the light. Shades of grey are created by blocking the light partially.
Colour is determined by sending the subpixels different commands. If the red, green, and blue subpixels let the same amount of light pass, a neutral grey or complete white light is created. By varying the light intensity among the red, green, and blue subpixels the entire colour spectrum can be reproduced.