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:
Apr. 13, 2004
Filed:
Apr. 13, 2000
Applicant:
Inventor:
Shigeo Yamaguchi, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 ; G11B 2/018 ;
U.S. Cl.
CPC ...
G11B 7/00 ; G11B 2/018 ;
Abstract
A drive device having an improved capability of reproducing data is disclosed. If an error occurs during a reproducing operation, reproduction is retried after changing amplitude reference values depending on whether the recording laser power is adequate. This makes it possible for the retrying operation to successfully read data that the previous reproducing operation failed to correctly read owing to an inadequate recording laser power. The determination as to whether the recording laser power is adequate is performed on the basis of the degree of asymmetry of the waveform of a data signal read by head means.