DIFFUSING SHEET, MOLDING DIE FOR DIFFUSING SHEET AND TRANSMISSION TYPE SCREEN

摘要

PROBLEM TO BE SOLVED: To provide a diffusion sheet in which uniformity of brightness in an image plane is good, there is little change of brightness of the observed image even when an observer moves in a horizontal direction and the image is easy to see and to provide a transmission type screen using the same. SOLUTION: In the diffusion sheet, a plurality of unit lens sections 11 (11a and 11b) constituted of a nearly trapezoidal column are arranged so that their major axis directions are in parallel to each other and all faces of a long base 112 in a nearly trapezoidal shape of a section vertical to the major axis direction of the nearly trapezoidal column of the unit lens section 11 are on one flat surface of a light incident surface side. Further a light absorption section 12 which absorbs or/and shades external light entering from a side of a light emitting surface 113 is formed in a groove between adjacent unit lens sections 11 and light is totally reflected at sides 111 (111a and 111b) in a section of the unit lens section 11. The unit lens section 11a both sides of which of nearly trapezoidal shape are formed by a curve 111a protruding to the inside and the unit lens section 11b both sides of which of nearly trapezoidal shape are formed by a curve protruding to the outside, are alternatively arranged. COPYRIGHT: (C)2005,JPO&NCIPI