Patent Number: 8,794,799

Title: Optical sheet, surface light source device and transmission-type display device

Abstract: An optical sheet having both of an excellent light condensing function and an excellent scratch resistance is provided. An optical sheet includes: a sheet-like main body; at least three or more first unit shaped elements arranged on one surface of the main body; and second unit shaped elements arranged on the one surface of the main body. Each of the second unit shaped elements extend in parallel with in one direction on a sheet surface of the main body. A height H1 of each of the first unit shaped elements from the one surface is higher than a height H2 of each of the second unit shaped elements. A rate of an area occupied by the first unit shaped elements on the one surface is not more than 10.0%, when observed along a normal direction nd relative to the one surface.

Inventors: Ushiyama; Akinobu (Moriya, JP), Tomita; Akiko (Mihara, JP), Goishihara; Satoshi (Kazo, JP), Kojima; Hiroshi (Kawagoe, JP), Shimada; Takayuki (Saitama, JP), Hamashima; Mitsuhiro (Shinjuku-Ku, JP), Matsufuji; Kazuo (Nerima-Ku, JP), Tanaka; Kazuki (Kita-Ku, JP)

Assignee: Dai Nippon Printing Co., Ltd.

International Classification: F21V 5/02 (20060101)

Expiration Date: 8/05/12018