Patent ID: 7802895
Filing Date: 2010-09-28
Classification: G02B,G02F

Abstract:
1. A direct-type backlight device comprising: a reflecting plate; a plurality of point light sources; and a light diffusing plate which receives direct light from said point light sources and reflected light from said reflecting plate on a light receiving surface thereof, and then diffuses and emits the light from a light emitting surface thereof, said reflecting plate, said point light sources and said light diffusing plate being placed in this order, wherein: at least either one of said reflecting plate and said light diffusing plate is provided with an image forming position adjusting member which produces images A said four point light sources A, B, C and D being selected among said plurality of point light sources such that said four point light sources constitute a convex quadrilateral which has the smallest area and the shortest circumference length, and said images A wherein L(XY) indicates a length of a line segment XY.