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:
Mar. 05, 2002
Filed:
Mar. 01, 1999
Applicant:
Inventors:
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/13 ;
U.S. Cl.
CPC ...
G11B 7/13 ;
Abstract
The present invention provides a large scale integrated circuit (LSI) for calculating servo signals (e.g., a focusing signal, a tracking signal, etc.) from the output signals received from a plurality of photo detectors, as used within an optical disk apparatus. The invention provides a switching circuit and a gain changing circuit coupled to the LSI such that a single LSI may be used for at least two different photo detector configurations as may be found in at least two different pick-up devices.