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:
Mar. 08, 1988
Filed:
Sep. 24, 1986
Saburo Funada, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An optical information-recording/reproducing apparatus comprises a beam-irradiator for irradiating a beam to an optical information-recording medium having a pre-format portion containing an address signal, and a data portion including an area in which information signals are to be recorded, a reflected-beam detector for producing an electric signal corresponding to the reflected beam from the recording medium, an error-signal detector for detecting an error signal for tracking control and/or focussing control of the beam, based on the electric signal, an information signal detector for detecting an information signal to be recorded in the data portion of the recording medium, based on the electric signal, a pre-format portion detector for detecting the pre-format portion of the recording medium, based on the electric signal, an offset-canceller for overlapping the error signal from the error signal detector and a compensation signal corresponding to the substantial difference of DC offset components between the data portion and pre-format portion detected by the pre-format detector and a controller for controlling tracking and/or focussing of the beam, based on a signal which is generated when the DC offset components contained in the error signal are compensated by said offset canceller.