Patent ID: 6312787
Filing Date: 2001-11-06
Classification: B29C,B29L,B32B,G02B,Y10S,Y10T

Abstract:
A surface light source element comprising:a resin sheet having a laminate structure in which a transparent resin layer C is sandwiched between and adjacent each of a transparent resin layer A and a transparent resin layer B, and a smooth an outer surface, any two adjacent resin layers of the three resin layers having refractive indexes which differ from each other, in a cross-section represented by an xy plane wherein y is a thickness direction of the a resin sheet, and x is a width direction thereof, at least one of two interfaces formed between the resin layers A and C and between the resin layers B and C having an uneven shape formed by repeated plural depressions and protrusions, as a light guide,a reflective material arranged on a lower surface of the light guide,a light source placed at least on one end surface (yz plane) in an x direction of the light guide, anda light-deflecting sheet placed on an upper surface of the light guide and having a function of changing a direction of light which is allowed to exit from a surface thereof to a normal direction thereof.