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.

Date of Patent:
Mar. 02, 2004

Filed:

Jul. 02, 2001
Applicant:
Inventor:

Yutaka Osada, Kanagawa-ken, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/005 ;
U.S. Cl.
CPC ...
G11B 7/005 ;
Abstract

A period accumulating portion inputs a reference clock “Clock 2” and a wobbling pulse WBLPOL_I obtained by binarizing a wobbling signal extracted from a reproduction output from a DVD, and accumulates and counts reference clocks “Clock 2” in an interval of predetermined periods of the wobbling pulses WBLPOL_I so as to obtain a count value “m”. An average period detecting circuit obtains an average count value “n” corresponding to the interval of an averaged period of the wobbling pulse by dividing a count value of the reference clock “Clock 2” with a number of the predetermined periods. A divider generates a wobbling pulse WBLPOL_O having a constant period, deprived of a period fluctuation due to a prepit by dividing the reference clock based on the average count value. The phase of that generated wobbling pulse WBLPOL_O having the constant period is matched with the phase of a land prepit LPP by a LPP generating circuit, a phase comparator, an AC phase shifter and a PLL circuit, and the wobbling pulse, whose phase is matched, is outputted as a recording/reproducing clock signal WTCLK.


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