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. 19, 1993
Filed:
Mar. 27, 1991
Akira Matsueda, Hachioji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An erase mark detecting circuit and an optical information recording/reproducing apparatus in which the erase mark detecting circuit is applied in a suitable manner, in which an erase mark is superimposed on a predetermined portion of an information unit, such as information track and information sector, the erase mark is detected in accordance with a mean level of a data reproducing signal of the erase mark superimposed region and an existence of information data recorded on said predetermined portion. Therefore, according to the invention, the erase mark can be detected in a correct and stable manner without being influenced by the content of the information data recorded on the information unit or the recording method of the information data.