EPSON HTPS

TN=Twisted Nematic
The Nematic liquid crystal molecules injected between two glass plates are aligned so that they twist by and angle of 90-degree between the glass plates without an applied voltage (OFF stage).

In this stage, light is transmitted thus a "white" image is shown. When a voltage is applied (ON), the liquid crystal molecules are set upright in a vertical direction, thus light is blocked and a "black" image is shown.

This is called the normally white mode.

In this case, a certain degree of light leakage occurs since not all liquid crystal molecules turn into the same (upright) direction, causing a lower contrast with lighter blacks.

VA=Vertical Alignment
Vertical Alignment technology means that without a voltage applied, liquid crystal elements stand upright (vertical) and block the light to display a "black" image. When a voltage is applied (ON), the liquid crystal molecules align horizontally and light istransmitted to display a "white" image.

This is called the normallyblack mode.

Since all liquid crystal molecules turn into the same direction when no voltage is applied, there is less light leakage and thus the black level is better, resulting in a higher contrast.