A backlight device (100) includes a light guide plate (110), a light
source (130) arranged at a side face of the light guide plate, a lamp
cover (140) surrounding the light source, a light reflection plate (120)
arranged below the light guide plate, a light diffusion plate (150)
arranged over the light guide plate, and a brightness enhancement plate
(160) arranged over the light diffusion plate. The light diffusion plate
has a first optical film (151) and a plurality of first bumps (152)
formed thereon and extending outwardly and toward the light guide plate.
The brightness enhancement plate has a second optical film (161) and a
plurality of second bumps (162) formed thereon and extending outwardly
and away from the light diffusion structure.