Convex / concave pattern forming sheet, light diffuser, master plate for light diffuser production stamper, light diffuser production stamper

摘要

PROBLEM TO BE SOLVED: To provide a rugged pattern formation sheet that can be used as a light-diffusion body capable of sufficiently enhancing antiglare property and illuminance and excellent in isotropic light-diffusion property, even when the sheet is used for a surface light source device in which a plurality of light-emitting diode light sources is two-dimensionally distributed.SOLUTION: The rugged pattern formation sheet has a first rugged pattern 13a along one direction and a second rugged pattern 14a along a direction approximately orthogonal to the first rugged pattern 13a, formed on a surface of a sheet comprising at least one kind of light-transmitting resin. Each average pitch of the first and second rugged patterns is more than 1 m and 50 m or less; and an average depth of the first and second rugged patterns is 10% or more of the average pitch set to 100%.