PRISM SHEET, SURFACE LIGHT SOURCE APPARATUS USING THE SAME, AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To solve the technical problem that a white point is caused by giving abrasion to the light emission surface of a light guide body by a prism row top part of a prism sheet without lowering luminance in a normal line direction of the light emission surface of the light guide body and without increasing the number of components.

SOLUTION: The prism sheet is used as a light deflecting element in a surface light source apparatus of an edge light system. A light incident surface 41 which is one main surface is made to be a prism row forming surface where a plurality of prism rows 411 are arranged in about parallel to each other. A light emitting surface 42 which is another main surface is made to be a flat surface. A material constituting the prism row 411 has a modulus of pushing elasticity of ≤1000 MPa at 25°C and the modulus of pushing elasticity of ≥90 MPa at 60°C. The prism row 411 is formed at a prism part 44 joined to a transparent base material 43 and has a flat part 411c of 0.2 to 3 μm width at its top part.

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