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. 01, 2008
Filed:
Feb. 14, 2007
Masaaki Tsuji, Ohsaka-fu, JP;
Ryohsuke Sugiyama, Ohsaka-fu, JP;
Masaaki Tsuji, Ohsaka-fu, JP;
Ryohsuke Sugiyama, Ohsaka-fu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An optical disk recording apparatus includes a first comparator, a second comparator, a third comparator, a selection circuit, a control voltage generator, a voltage control oscillator, and a control circuit. The first comparator compares frequency-divided signals to output an error signal. The second and third comparators compare a signal pre-recorded on an optical disk and the frequency-divided signal to output an error signal and a frequency differential signal. The selection circuit selects any one of the error signals to output the signal selected. The control voltage generator generates a control voltage from the signal from the selection circuit. The voltage control oscillator generates and outputs the write reference clock signal having a frequency corresponding to the control voltage from the control voltage generator. The control circuit controls operations of the selection circuit according to the frequency differential signals.