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. 07, 2008
Filed:
Mar. 10, 2006
Youichi Ogura, Ibaraki, JP;
Toshihiko Takahashi, Kawachinagano, JP;
Shinichi Konishi, Nara, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a jitter detection apparatus, a playback RF signaldetected from an optical disc mediumis subjected to waveform shaping, and thereafter, converted into a digital RF signalwith a sampling clock having a cycle twice as long as a cycle of a channel clock. Thereafter, an offset variation in a high-frequency band is corrected by an offset correction circuit, and data that are missing in the time direction are restored by a Nyquist interpolation filter. Then, positions where jitter is to be extracted are selected from an output signal of the Nyquist interpolation filter, by a jitter detection preprocessing circuit, according to the playback speed of the optical disc mediumand the arithmetic capacity of a digital signal operation circuit, whereby highly accurate jitters can be extracted by using the digital signal operation circuit