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:
Apr. 09, 1991
Filed:
Sep. 22, 1988
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
An optical information recording/reproducing apparatus includes signal recording means for recording a signal on a film. The signal is recorded by raising the temperature of the film with a writing laser beam. A signal reproduction apparatus reproduces the signal by irradiating the film with a reading laser beam. There is an optical system provided in common to both the writing laser beam and the reading laser beam. The signal recorded on the film is reproduced substantially simultaneously with the recording of the signal in order to allow for confirmation of the signal that has been recorded. A modulating circuit is provided for modulating the intensity of the writing laser beam with a frequency of at least twice as high as the maximum frequency of the signal to be recorded.