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. 28, 1999
Filed:
Aug. 26, 1997
Applicant:
Inventor:
Takayuki Sasaoka, Kanagawa, JP;
Assignee:
Mitsumi Electric Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 54 ; 369 4413 ; 369 4441 ;
Abstract
An output from a left half light-receiving portion C1, C4 of a main-beam photodiode 5 of an optical pickup and an output from a right half light-receiving portion C2, C3 of a main-beam photodiode 5 of an optical pickup are normalized, and the difference between the normalized outputs is calculated.