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:
May. 04, 1993
Filed:
Feb. 07, 1992
Isamu Nakao, Tokyo, JP;
Atsushi Fukumoto, Kanagawa, JP;
Toshiki Udagawa, Tokyo, JP;
Shunji Yoshimura, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A method and apparatus for recording and reproducing information onto and from a magneto-optic recording medium is disclosed. The magneto-optic recording medium has at least a reproducing layer and a recording layer. A recording optical head records information on the magneto-optic recording medium. A reproducing optical head has a reading light beam for reading information recorded in a region within a spot of the reading light beam by magneto-optic effect by changing a state of magnetization of the reproducing layer and at the same time irradiating the recording medium with the light beam. A wavelength of the recording light beam emitted by the recording optical head is substantially smaller than a wavelength of the reading light beam emitted by the reading optical head. A minimum ratio of the wavelength of the recording light beam to that of the reproducing light beam is 1:3.