Patent ID: 7314301

Claim:
A back light unit comprising: a plurality of light emitting diodes (LEDs) arranged in a matrix manner and used to generate light; a light guide panel comprising a light-exit surface and an incident surface, the incident surface comprising a plurality of incident blocks arranged in a matrix manner correspondingly positioned beside the plurality of LEDs, and each incident block comprising a recess extending away from a corresponding LED, the recess comprising a plurality of surfaces with different normal vectors and different slopes for scattering light emitted from the corresponding LED, an absolute value of the different slopes of the plurality of surfaces increasing as measured when moving from a periphery of the recess toward a center of the recess; a reflection film used to reflect light generated from the plurality of LEDs; and a diffuser sheet positioned at one side of the light-exit surface of the light guide panel and used to diffuse light passes through the light guide panel.