Patent ID: 7517105
Filing Date: 2009-04-14
Classification: G02F

Abstract:
1. A surface light source unit comprising: a box body of a tray shape, whose bottom surface is quadrilateral, whose upper side is open, on a bottom surface and side walls of which a light diffused-reflection member is provided, the side walls being inclined outward, and semiconductor light emitting devices provided on at least two corners of edge parts of the bottom surface of the box body so as to irradiate light toward center parts of the side walls opposite to the corners, wherein the semiconductor light emitting devices have a directionality of 45 to 60 degrees, and the light irradiated from each semiconductor light emitting device is mixed mutually in the box body by being reflected diffusedly on the bottom surface and the side walls of the box body, and is averaged in brightness, chromaticity and luminescent hue, and wherein an inclined angle and a height of the side walls of the box body are set so as to make brightness on the opened upper surface above the side walls of the box body and above a center part of the box body substantially equal.