The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 11, 2014
Filed:
Nov. 16, 2011
Akimasa Yuuki, Tokyo, JP;
Kenji Itoga, Tokyo, JP;
Naoko Iwasaki, Tokyo, JP;
Takafumi Kokusho, Tokyo, JP;
Yuji Tsuchiyama, Tokyo, JP;
Seiji Sakai, Tokyo, JP;
Akimasa Yuuki, Tokyo, JP;
Kenji Itoga, Tokyo, JP;
Naoko Iwasaki, Tokyo, JP;
Takafumi Kokusho, Tokyo, JP;
Yuji Tsuchiyama, Tokyo, JP;
Seiji Sakai, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
It is an object of the invention to provide a technique capable of suppressing variations in luminance in the vicinity of a light entrance surface of a light guide plate. An illumination device includes a point light source, and a light guide plate having a side surface serving as a light entrance surface opposed to the point light source, and a main surface serving as a light exit surface. The light entrance surface of the light guide plate is provided with unevenness formed by arraying at predetermined pitches a plurality of protrusions each projecting from the light entrance surface and extending in a direction perpendicular to the light exit surface. Each of the top surface and the bottom surface of the unevenness is provided with a plurality of micro protrusions each extending in the direction perpendicular to the light exit surface and having a height smaller than the above protrusion.