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:
Jul. 10, 2007
Filed:
Feb. 20, 2004
Shin-ichi Yamada, Osaka, JP;
Yuuichi Kuze, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Kenji Kondo, Osaka, JP;
Akira Yoshikawa, Nara, JP;
Shin-ichi Yamada, Osaka, JP;
Yuuichi Kuze, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Kenji Kondo, Osaka, JP;
Akira Yoshikawa, Nara, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
A tracking error signal generation device includes a splitting and convergence section for splitting an optical beam into a main beam and a sub beam; a two-portion main beam detection section for detecting the main beam; a main beam push-pull signal generation section for generating a main beam push-pull signal; a two-portion sub beam detection section for detecting the sub beam; a sub beam push-pull signal generation section for generating a sub beam push-pull signal; a displacement amount detection section for detecting a displacement amount of the main beam push-pull signal from a reference value based on the main beam push-pull signal and the sub beam push-pull signal; and a tracking error signal generation section for generating a tracking error signal by correcting either the main beam push-pull signal or the sub beam push-pull signal based on the displacement amount.