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. 11, 2012
Filed:
Mar. 07, 2008
Katsuhiko Izumi, Kamakura, JP;
Kazuyoshi Yamazaki, Kawasaki, JP;
Tomoto Kawamura, Tokyo, JP;
Kunikazu Ohnishi, Yokosuka, JP;
Katsuhiko Izumi, Kamakura, JP;
Kazuyoshi Yamazaki, Kawasaki, JP;
Tomoto Kawamura, Tokyo, JP;
Kunikazu Ohnishi, Yokosuka, JP;
Hitachi Media Electronics Co., Ltd., Iwate, JP;
Abstract
For use with a multi-layer optical disc, an optical pickup can eliminate a problem of causing a focus error signal and a tracking error signal to fluctuate due to interference of a signal light beam with a return light beam from another recording surface of a multi-layer optical disc during reproduction with an optical pickup that produces a tracking error signal and a focus error signal from a difference signal based on polarized reflected light.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile