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:
Jun. 23, 1998
Filed:
Jan. 27, 1997
Yoshihiro Saga, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In an optical information recording/reproducing apparatus capable of executing a first recording method for recording information on either one of a land portion and a groove portion of a recording medium and a second recording method for recording information on both of the land portion and the groove portion, the recording medium is irradiated with a light beam, and a tracking error signal and/or focusing error signal is generated from the reflected light upon irradiation of the light beam. The level of the error signal is compared with a reference level to detect a tracking error state and/or focusing error state. The reference level is adapted to be switched according to the first or second recording method.