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. 06, 2002
Filed:
Jun. 25, 2001
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/76 ;
U.S. Cl.
CPC ...
G11B 5/76 ;
Abstract
Information recorded on an optical disk in accordance with a mark edge recording scheme is detected by a center detection circuit which includes a bisected beam detector to obtain a mark center position signal. In succession, the mark center position signal is converted to a mark edge position signal by an edge signal generating circuit. An information reproducing device is implemented which is capable of performing reproducing operation on an information medium conforming to a high-density mark edge recording scheme and which is stable against changes of recording paper, recording sensitivity and reflectivity.