The subpixels in an LCD color screen use liquid crystal molecules that act as dimmer switches controlled by voltage. Depending on the type of TV or monitor, the liquid crystals change their orientation from 60 to 240 times per second. For a monochrome example, see seven-segment display
. For more on the popular IPS screens, see IPS panel
. See LCD
In a 4K TV, there are eight million pixels, each with three subpixels. The liquid crystals start out looking like twisted ladders because they orient themselves to microscopic grooves, called "rubbings," in the top and bottom polarization panels (at right angles to each other). In this zero voltage example, the backlight reaches all three filters at maximum brightness, and the red, green and blue subpixels create white (see RGB
When voltage is applied, the liquid crystals twist away from the polarizers. The more they twist from their 90 degree orientation, the less light reaches the RGB filters. Shades of gray are produced when the red, green and blue lights are at uniform brightness, but not maximum. All colors are displayed at the pixel level by applying the appropriate voltage to each of the subpixels.