In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting...http://www.google.fr/patents/US5995288?utm_source=gb-gplus-shareBrevet US5995288 - Optical sheet optical sheet lamination light source device, and light-transmissive type display apparatus
