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. 30, 1993
Filed:
Sep. 05, 1991
Satoshi Shikichi, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A data processing apparatus includes a light source and an objective lens for radiating first and second light beams on a recording medium having a plurality of data and trucking tracks alternately formed and parallel to each other, photodetectors for detecting the tracking error signal from a beam obtained by reflection of the second light beam by the medium, a switching circuit for selectively supplying the tracking error signal to an actuator, a circuit for supplying a moving signal to the actuator to move the first and second light beams, respectively, to a data track different from one data track and a tracking different from one tracking track, and a control unit for monitoring the tracking error signal, for switching the switching circuit to supply the tracking error signal to the actuator in a tracking mode in which a data track is traced with the first light beam, and for switching the switching circuit not to supply the tracking error signal to the actuator in a moving mode for moving the first light beam to a different data track, the control unit interrupting monitoring of the tracking error signal during a period for which the second light beam is passing data tracks in the moving mode.