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:
May. 29, 2001
Filed:
Nov. 25, 1998
Kouichi Takamine, Kawanishi, JP;
Kenji Fujiune, Neyagawa, JP;
Akihiro Hatsusegawa, Kyoto, JP;
Hiroyuki Yamaguchi, Nishinomiya, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
While discerning whether the laser beam spot is positioned on a land track or a groove track according to the L/G switch signal LGS from the land groove detection unit,, the focus position rough detection unit,and the focus position precise detection unit,detect two new focus positions (for the land and the groove) so that the bit error rate BER that is measured in the error rate measurement unit,and the envelope of and the jitter in the reproduction signal RF would improve, and output two control signals (FBAL and FOFF) for changing the control target position into the new two focus position to the focus error detection unit