Why does black appear washed out on an LCD screen?

I. First, let's look at why black screens on LCDs sometimes appear "washed out."

LCDs (Liquid Crystal Displays) themselves do not emit light; they achieve display by "controlling the amount of backlight transmitted through liquid crystal molecules."

Theoretically, when displaying black, the liquid crystal molecules should completely block the backlight—but in reality, 100% shielding is not possible.

The main reasons include:
* The liquid crystal molecules cannot completely block light; the torque of the liquid crystal does not reach 90°, resulting in some light leakage;
* Light scattering from the polarizer and light guide plate;
* Differences in panel types (TN is the most severe, IPS is slightly better, and VA is the best).