A backlight 7 has light sources 2, a flat-plate-shaped light guide plate 3 for guiding the light emitted from the light sources 2 in a predetermined direction, a light shield louver 5, disposed so as to face the light guide plate 3, for shielding part of the light emerging from the light guide plate 3 according to angles of incidence, and a prism sheet 8 for converting the brightness distribution of the light incident on the light shield louver 5 into a predetermined brightness distribution. Owing to the prism sheet 8, the light incident on the light shield louver exhibits a brightness distribution such that brightness is at a minimum at an angle of incidence of 0°. Thus, the backlight 7, and a liquid crystal display device 1 employing it, permits light to emerge therefrom within a desired range of viewing angles while offering high brightness within that range, with reduced degradation of viewability.

Title
Backlight and liquid crystal display device
Application Number
9/921753
Publication Number
20020018341
Application Date
August 6, 2001
Publication Date
February 14, 2002
Inventor
Kenichi Ukai
Nobuyuki Takahashi
Hiroshi Torihara
Agent
Nixon & Vanderhye PC
VA, US
IPC
F21V 07/04
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