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:
Oct. 12, 2004
Filed:
May. 23, 2001
Applicant:
Inventors:
Norio Shoji, Kanagawa, JP;
Junkichi Sugita, Kanagawa, JP;
Kimimasa Senba, Kanagawa, JP;
Toshihiro Kawakubo, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 5/09 ; G11B 2/014 ; H03L 7/06 ; H03L 7/08 ; H03L 7/14 ;
U.S. Cl.
CPC ...
G11B 5/09 ; G11B 2/014 ; H03L 7/06 ; H03L 7/08 ; H03L 7/14 ;
Abstract
A PLL circuit functioning as a clock recovery circuit in a tape recording and playback apparatus employing the PRML method has a level determining circuit for detecting that head output level (signal level) is at or lower than a certain level during track crossing for a high-speed search, and effects a hold on a loop filter according to a level determination output to thereby hold PLL operation, whereby the PLL behavior is not disturbed by a noise component occurring during track crossing. Thus, it is possible to stabilize search operation and increase the design margin.