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:
Feb. 05, 1991
Filed:
Mar. 06, 1989
Akira Wada, Kyoto, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information recording and reporducing apparatus for recording and reproducing information optically against recording material, includes means for generating a first light beam for reproducing and erasing information which is previously recorded in the recording material, and means for providing a second light beam for recording new information into the recording material, and irradiation of the first light beam and the second light beam to an arbitrary point on the recording material is conducted in the above-mentioned order. Another type recording and reproducing apparatus includes an optical head which introduces a light beam onto optical information recording material and takes out a reproduced signal from the optical information recording material, means for applying a magnetic field whose polarity is in accordance with writing-in information to the recording material, and means for demodulating the signal reproduced from the optical head, and the light beam is made have no modulation and the level thereof is set at a level which gives a rise to above Curie temperture which is required for the writing-in at the writing-in operation, and the signal reproduced from the recorded information by the optical head direct before rewriting is demodulated and monitored.