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:
Dec. 03, 1991
Filed:
Jul. 30, 1990
Hideki Kitazawa, Kawagoe, JP;
Ryohei Terada, Kawagoe, JP;
Shogo Takeuchi, Kawagoe, JP;
Tsutomu Kayama, Kawagoe, JP;
Kohichi Tanimoto, Kawagoe, JP;
Nobuo Utsugi, Kawagoe, JP;
Yoshiaki Nagai, Kawagoe, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A display board illuminating device includes a light guide plate arranged to face the back of a display board and a light source disposed to face the side end of the light guide plate. The side end of the light guide plate is inclined toward the center of the light guide plate in the direction of the display board. By this configuration an angle of an optical axis refracted at the surface of the side end and incident into the light guide plate with respect to a main surface of the light guide plate, so that the whole area of the display board is illuminated efficiently.