Patent ID: 6981792

Claim:
A backlight device, comprising: a light source, and a light guide plate having an end surface adjacent to the light source and an emitting surface; wherein light components from the light source are introduced into the light guide plate through the end surface of the light guide plate to emit light from the emitting surface as illuminating light; wherein the emitting surface has a plurality of wedge-shaped grooves in stripes and a light diffusion surface having micro-protrusions formed between adjacent wedge-shaped grooves; wherein light components incident on the light diffusion surface form a first transmitting light component diffusing and emitting from the emitting surface of the light guide plate as illuminating light; and wherein light components incident on the wedge-shaped grooves are split into a second transmitting light component diffusing and emitting from the emitting surface of the light guide plate as illuminating light and a reflected light component is re-introduced into the wedge-shaped grooves or the light diffusion surface so as to be emitted from the emitting surface of the light guide plate as illuminating light.