An optical sheet has a transparent base material; a fine lens array constituted by a plurality of fine unit lenses formed on a front surface of the transparent base material; a diffusing layer formed on a rear surface of the transparent base material opposite to the surface on which the fine lens array...http://www.google.de/patents/US6822707?utm_source=gb-gplus-sharePatent US6822707 - Optical sheet and display device having the optical sheet
