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. 24, 1984
Filed:
Dec. 23, 1981
Applicant:
Inventors:
Kimiaki Yamamoto, Hachiouji, JP;
Kenichi Ito, Hachiouji, JP;
Assignee:
Olympus Optical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 44 ; 369 46 ; 369109 ;
Abstract
In a signal detecting system in an optical information reading apparatus wherein, in order that a tracking signal having few errors can be obtained, the pupil of an objective used to project a light from a light source as a spot onto the information recording track of a disk, collect the light reflected on the disk and lead it to a light receiving device is covered in the form of a band or a cover plate placed in front of detectors of the light receiving device to intercept a part of the light entering the dectector.