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:
Aug. 04, 2009
Filed:
Jul. 18, 2006
Akira Mashimo, Tokorozawa, JP;
Akira Mashimo, Tokorozawa, JP;
TEAC Corporation, Tama-shi, JP;
Abstract
An address is reliably demodulated when a phase shift in a wobble signal has been induced by a crosstalk signal from an adjacent track. Address information is modulated by a binary phase modulation scheme and embedded into an optical disk as a wobble signal. A 0-degree phase wobble signal and a 180-degree phase wobble signal are brought out of phase with each other by crosstalk from an adjacent track. An address decoder performs exclusive-OR operation of the wobble signal and a reference clock signal, to thus compute a ratio at which an exclusive-OR result assumes a value of 1 (H) every half period of the reference clock signal. The thus-computed ratio is compared with a threshold ratio. The threshold ratio is usually set to 50%. However, when a phase shift has been caused by crosstalk, a system controller changes the threshold ratio to a ratio of 50% or less.