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:
Oct. 06, 1992
Filed:
Aug. 08, 1991
Kazuo Noda, Yokohama, JP;
Koichi Yamazaki, Sakado, JP;
Nippon Conlux Co., Ltd., Tokyo, JP;
Abstract
An apparatus for optically recording and reproducing information in and from an optical information recording medium having a guide track. The apparatus uses an optical head having a diffraction grating, for recording and reproducing information. In recording information, a zero-order diffraction light beam from the diffraction grating is used for the information recording, and plus/minus first-order diffraction light beams from the diffraction grating are used for the tracking. In reproducing information, the zero-order diffraction light beam is used for the tracking, and higher- and odd-order diffraction light beams including at least plus/minus first-order diffraction light beams are used for information reproduction.