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.

Date of Patent:
Mar. 09, 2004

Filed:

Feb. 20, 2002
Applicant:
Inventor:

Kyoko Tadaki, Kawasaki, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 2/740 ; G02B 2/764 ; G11B 7/00 ; G11B 5/56 ; G11B 5/58 ;
U.S. Cl.
CPC ...
G02B 2/740 ; G02B 2/764 ; G11B 7/00 ; G11B 5/56 ; G11B 5/58 ;
Abstract

An optical data-processing apparatus is provided for writing data to a data storage disk or reading data from the disk. The data-processing apparatus includes first and second light splitters. The first splitter splits reflected light from the storage disk into two semicircular rays. The second splitter splits these two semicircular rays into non-biased light and biased light. The data-processing apparatus also includes an optical detector for receiving the non-biased light and the biased light, thereby producing a first signal corresponding to the non-biased light and a second signal corresponding to the biased light. Based on the first and the second signals, a focus error signal and a spherical aberration signal are produced.


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