Patent ID: 7196845
Filing Date: 2007-03-27
Classification: G02B,G03B

Abstract:
1. A Fresnel lens sheet comprising a Fresnel lens substrate and a Fresnel lens, whose surface of the light source side has a rugged structure with an average pitch of 200 μm or smaller and ten point roughness of 3 to 15 μm, wherein said Fresnel lens substrate comprises a thermoplastic resin in an amount of 100 parts by weight and light diffusible fine particles with the average particle diameter of 13 to 30 μm and with an index of refraction satisfying the following equation (1): wherein Np represents an index of refraction of the thermoplastic resin, and Ns represents an index of refraction of light diffusible fine particles, in an amount of 6 to 30 parts by weight.