The basic principle is simple: a display screen consists of a number of pixels that can emit light of any color, and controlling each pixel to display a corresponding color does the trick. In TFT LCD, backlight technology is generally adopted. In order to accurately control the color and brightness of each pixel, a switch similar to a shutter needs to be installed after each pixel. When the “shutter” is opened, light can come through, but when the “shutter” is closed, light cannot come through.

Of course, it’s not as simple technically as that. Liquid Crystal Display USES the properties of Liquid crystals (Liquid when heated and solid when cooled)

There are three types of liquid crystals:

• Clay-like lamination (Smectic) liquid crystals
• Nematic liquid crystal resembling a thin matchstick
• The Cholestatic liquid crystal

Liquid crystal displays (LCDs) are filamentous, and their molecular structure changes as the environment change, giving them different physical properties — allowing light to pass through or block it — in the case of louvers.

You know the three primary colors, so each pixel on the display needs to be made up of three similar basic components described above, which control the red, green, and blue colors respectively.

TFT color filter is divided into red, green, and blue according to the color, which is successively arranged on the glass substrate to form a group (dot pitch) corresponding to a pixel. Each monochrome filter is called a sub-pixel. That said, if a TFT display supports a maximum resolution of 1280×1024, it needs at least 1280×3×1024 sub-pixels and transistors. For a 15-inch TFT display (1024 x 768), a pixel is about 0.0188 inches.