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:
Nov. 02, 1993
Filed:
Dec. 11, 1987
Applicant:
Inventors:
Norio Matsuda, Saitama, JP;
Seiichi Ohsawa, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4435 ; 369 4432 ; 369 4434 ; 369 54 ;
Abstract
A tracking error signal generating device using a four-segment detector in which signals from diagonally opposed elements are combined and the two so combined signals are phase compared. According to the invention, either before or during the combining, the output signals of the segments have high level components removed so as to reduce offsetting due to a non-uniform beam illuminating the detector.