The brightness is light intensity of the emitted object sew by eyes from one direction. Units is candelas / square meter [cd/m2] or called nits, the symbol L, it means the luminous flux issued by object in certain direction and unit solid angle of unit area, 1 cd / m² is equal to 1 m² surface issue 1 candelas luminous intensity. Brightness is the light intensity of human feelings, it is a subjective quantity.

In formula:
Φ: luminous flux
Ω: solid angle
θ: the angle between the given direction and unit area normal direction (ds).

There are two way to increase display brightness, one is to improve the light passing rate of the panel; another is to increase the brightness of the backlight, which increased the number of lamps.