Patent ID: 6425673
Filing Date: 2002-07-30
Classification: G02B

Abstract:
A light guide pipe comprising:a light incident surface, a light emitting surface orthogonal to said light incident surface, a reflecting surface opposed to said light emitting surface; and a light extractor formed on at least a part of at least one of said light emitting surface and said reflecting surface, wherein said light extractor comprises a plurality of surface-roughened protrusions and/or concaves provided in at least one surface of said light guide pipe wherein said light guide pipe comprises a square shape and a scatter enhancing region in a triangular portion of said reflecting surface and/or light emitting surface having as base said light incident surface, said light emitting surface, or said light reflecting surface; and said scatter enhancing region being set from 1.2 to 2 times higher in density of roughened protrusions and/or roughened concaves compared to a light source unit in which said scatter enhancing region is not provided.