The Principles Behind LCD Technology 1. In this section, we will explain everything ranging from the properties of liquid crystal molecules to the basic principle of display technology by using TN type liquid crystals as an example. The parallel arrangement of liquid crystal molecules along grooves When coming into contact with grooved surface in a fixed direction, liquid crystal molecules line up parallelly along the grooves. Natural state Molecules are arranged in a loosely ordered fashion with their long axes parallel.
Molecules line up parallel along grooves.
When the molecule arrangement is twisted 90 degrees as shown in the figure, the light also twists 90 degrees as it passes through the liquid crystals. Molecules rearrange themselves when voltage is applied When voltage is applied to the liquid crystal structure, the twisted light passes straight through. The molecules in liquid crystals are easily rearranged by applying voltage or another external force. Blocking light with two polarizing filters When voltage is applied to a combination of two polarizing filters and twisted liquid crystal, it becomes a LCD display. Light passes when two polarizing filters are arranged with polarizing axes as shown above, left.