PRISM SHEET AND PRODUCTION METHOD THEREOF AND SURFACE LIGHT SOURCE DEVICE

摘要

A prism sheet provided with a prism row forming surface (41) on which a plurality of prism rows (411) extend in parallel to each other. The prism row forming surface (41) has roughened portions (412) each having a width W 0.04-0.5 times the arranging pitch P of the prism row and arranged between adjacent prism rows (411). The surface of the roughened portion (412) is larger in roughness than the prism surface (411a, 411b) of the prism row (411). The surface of the roughened portion (412) has a center-line average roughness Ra of 0.3-2 mum and a ten-point average roughness Rz of 1-3 mum, and the prism surface (411a, 411b) of the prism row has a center-line average roughness Ra of less then 0.3 mum and a ten-point average roughness Rz of less than 1 mum.