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:
Sep. 21, 1993
Filed:
Jan. 22, 1993
Mikio Sato, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In apparatus for recording information and/or reproducing information by irradiating a light beam to a disk shaped optical recording medium, there are provided an adjusting mechanism for adjusting an irradiation state of the light beam to the recording medium, a detector for detecting an irradiation sate error signal of the light beam transmitted or reflected from the recording medium to the recording medium. Further, there are provided a feedback circuit, a storing device and providing circuit. In the feedback circuit, the irradiation state error signal obtained by the detector is sampled at a predetermined rate to generate a control signal for the adjusting mechanism by use of the sampled irradiation state error signal, and the control signal is fed back to the adjusting mechanism. The sampling of the irradiation state error signal is effected at a different rate from that in the detector and the sampled irradiation state error signal is stored in the storing device. The irradiation state error signal stored in the device is input to the feedback circuit by the providing circuit.