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:
Dec. 22, 2009
Filed:
Nov. 08, 2006
Kazunori Tokiwa, Tokyo-to, JP;
Kazunori Tokiwa, Tokyo-to, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
Reflected light caused by reflection of a laser beam at a first layer of an optical disc is converted into a main signal. Reflected light caused by reflection of the laser beam at a second layer of the optical disc is converted into a sub signal. An address of a currently-accessed position in the first layer is detected from the main signal. A reference address in the first layer corresponds to a boundary between a signal recorded area and a signal unrecorded area in the second layer. A specified address in the first layer corresponds to a position radially separated from the position at the reference address by an allowable range. A misalignment between tracks on the first and second layers is concluded to be within the allowable range in cases where the sub signal substantially takes a reference level when the detected address reaches the specified address.