Backlight module

Abstract

A backlight module includes a back plate, a light source disposed on the back plate, and a first optical film disposed on the back plate. The first optical film includes a first upper surface and a first lower surface, and the first upper surface is farther away from the back plate than the first lower surface, and has a first prism structure, wherein, at a first angle, a second angle and a third angle, the backlight module respectively has a first brightness value, a second brightness value and a third brightness value, which satisfy: ❘ "\[LeftBracketingBar]" [ ( A / C ) - ( B / C ) ] × 100 ⁢ % ❘ "\[RightBracketingBar]" ≧ 10 ⁢ % , where A, B and C represents the first, second and third brightness values, respectively, the third brightness value is the maximum brightness value of the backlight module, and the first, second and third angles are different from each other.

Dependencies are inferred from the claim text.