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:
Jan. 12, 1988
Filed:
Jun. 14, 1985
Applicant:
Inventor:
Hideyuki Kenjyo, Koganei, JP;
Assignee:
Olympus Optical Company Limited, Tokyo, JP;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 54 ; 369 58 ; 369124 ; 358336 ;
Abstract
A method of detecting defects formed on an optical record medium for use in an optical information recording and reproducing apparatus. The method comprises steps of deriving light output signals reflected from the record medium at the time of information writing, comprising the light output signals with reference signals which are set to a plurality of desired levels, and logically operating the compared output signals thereby detecting and evaluating the defects formed on the surface of the record medium.