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:
Jul. 31, 1990
Filed:
Sep. 02, 1988
Applicant:
Inventors:
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4412 ; 369 4441 ;
Abstract
An optical information processing apparatus including a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.