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:
May. 20, 2008
Filed:
Jan. 17, 2003
Masahito Nakao, Kadoma, JP;
Shigeru Furumiya, Himeji, JP;
Hiromichi Ishibashi, Ibaraki, JP;
Junichi Minamino, Nara, JP;
Naohiro Kimura, Uji, JP;
Masahito Nakao, Kadoma, JP;
Shigeru Furumiya, Himeji, JP;
Hiromichi Ishibashi, Ibaraki, JP;
Junichi Minamino, Nara, JP;
Naohiro Kimura, Uji, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method for reading address information from an optical disc with a wobbled track groove includes the steps of: obtaining a sine wave address signal, a first address signal representing a first groove region with sine wave wobbled portions and an inverted phase portion, and a second address signal representing a second groove region with steep inward or outward displacements; multiplying a first reference signal, being phase-locked to, and having the same frequency as, the sine wave address signal, and the first address signal together to obtain a first multiplied signal; multiplying a second reference signal, being phase-locked to, and having a frequency twice as high as, the sine wave address signal, and the second address signal together to obtain a second multiplied signal; integrating the first, multiplied signal and the second multiplied signal separately to obtain a first integral and a second integral, respectively; and adding the first and second integrals together.