How Does An LCD Monitor Work

An LCD screen works by a matrix of tiny light transistors that have two states; off an on. On a typical screen there will be millions of these and each one represents a pixel that is to be displayed on the screen.

There is polarised light behind the first and second layers of an LCD screen, which is filtered by liquid crystals in the second later; the liquid crystals don’t actually emit light, they merely control the light that passes through them. The light crystals are small thin rod like molecules that like to move in unison when you apply a voltage across them, and polarise in a certain direction to either allow light to pass through them, or polarise in another direction to prevent light from passing through them.

Each one of these is effectively a separate red, blue, or green light, where the the colours of the pixels are changed using liquid crystals to rotate polarised light with a certain frequency to control the spectrum of colours to be displayed with each pixel.