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. 04, 1995
Filed:
Jun. 01, 1993
Hidehiko Kando, Matsudo, JP;
Mamoru Kainuma, Ibaraki, JP;
Masaru Muranishi, Ibaraki, JP;
Katsuhiko Kimura, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An information processing apparatus such as an optical disc device which is provided with an integrated photo detector for transducing a reflected light beam from an optical information medium to an electric signal. The integrated photo detector used in the apparatus comprises a substrate; an optical guide formed on the substrate; and a plurality of integrated photo detecting sections each including a grating coupler for guiding the reflected light beam to the optical guide, and a photo detecting unit for detecting a guided light beam in the optical guide. The use of this integrated photo detector results in increasing error tolerance relative to incident angle and incident position to improve the incidence efficiency, thereby elevating the reliability of the apparatus.