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. 23, 2007
Filed:
Aug. 11, 2004
Toshiaki Fukui, Osaka, JP;
Toshiaki Fukui, Osaka, JP;
Funai Electric Co., Ltd., Osaka, JP;
Abstract
A bandpass filter receives a tracking error signal. An average/minimum frequency measurement circuit repeats measurement prescribed times, of an average frequency and a minimum frequency of a signal output from the bandpass filter. A standard deviation calculation circuit assumes the average frequency and the minimum frequency obtained by prescribed times of measurement as one variate, and calculates a standard deviation of this variate. A determination circuit determines an optical disc to be reproduced as a read-only optical disc when the standard deviation is equal to or larger than a prescribed value, while it determines the optical disc to be reproduced as a recordable optical disc when the standard deviation is smaller than the prescribed value.