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:
Apr. 10, 1990
Filed:
Sep. 22, 1988
Applicant:
Inventors:
Toshihiko Sano, Ome, JP;
Soichiro Ogawa, Tokyo, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01D / ;
U.S. Cl.
CPC ...
362 29 ; 362216 ; 362223 ; 362355 ;
Abstract
In order to make the brightness approximately uniform over a diffusion board, a back-light device is provided with a light transmission controlling film having a planar form in a shape of a projection of the lamp on the diffusion board. The film is disposed in parallel to the lamp axis between the lamp and the diffusion board.