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:
Jul. 30, 2013
Filed:
Feb. 26, 2009
Hiroya Kakimoto, Gunma, JP;
Hiroya Kakimoto, Gunma, JP;
Taiyo Yuden Co., Ltd., Tokyo, JP;
Abstract
Target levels in the PRML method are adaptively set under conditions of simplicity and a low cost. A method of setting a target level for reproduction of an optical information recording medium includes: a step of producing a reproduction signal from reflected light of laser light irradiated to an optical information recording medium; a step of performing waveform equalization processing, which depends on a predetermined partial response characteristic, on the reproduction signal to produce a waveform-equalized reproduction signal; a step of detecting peak levels for marks and spaces of a predetermined number of symbols from the waveform-equalized reproduction signal irrespective of a condition for a symbol adjoining each symbol; and a setting step of determining and setting values of a plurality of target levels, which is employed in Viterbi decoding and is arrayed with non-equal intervals among them, on the basis of a relative relationship among the detected peak levels.