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. 23, 2011
Filed:
Jul. 21, 2006
Koichiro Nishimura, Yokohama, JP;
Toru Kawashima, Mito, JP;
Mitsuru Harai, Tokyo, JP;
Tsuyoshi Toda, Kodaira, JP;
Koichiro Nishimura, Yokohama, JP;
Toru Kawashima, Mito, JP;
Mitsuru Harai, Tokyo, JP;
Tsuyoshi Toda, Kodaira, JP;
Hitachi Ltd., Tokyo, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Abstract
Test writing is executed while skipping areas where deviations are present on an optical disk to thereby improve accuracy and reliability of an optimum recording condition to be derived. A deviation detecting unit detects the deviations of a guide groove on the optical disk on the basis of a fluctuation amount of a focus error signal or a tracking error signal, and registers information of the detected deviations onto a memory. A test writing processing unit refers to the memory, and records and reproduces a test signal while skipping the areas where the deviations are detected.