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:
Aug. 15, 1995
Filed:
Nov. 30, 1992
Yutaka Osada, Fujisawa, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
An access control device for use in an optical disk system provided with an information recording disk medium having a concentric or spiral track for recording information thereon, a recording/reproducing head for recording information on or reproducing information from the information recording disk medium, a tracking actuator for controlling the head in such a manner to follow a center of a track, a tracking error detection circuit for detecting a difference between the position of the head and the center of the track and a tracking drive circuit for driving the tracking actuator. Further, the access control device is used to move the recording/reproducing head to a desired or target track. Furthermore, the access control device is provided with a relative speed detection circuit for detecting the relative speed of the head with respect to the target track and reference-speed signal generation means for outputting a signal indicating a reference value of the relative speed. Additionally, the tracking drive circuit is adapted to be controlled according to the tracking error signal after controlled according to a difference between an output of the relative speed detection circuit and the reference speed signal when tracking control operation is started. Thereby, when an operation to be currently performed by the system is changed to the tracking control operation, the tracking control operation can be stably started and performed. Further, an access time can be substantially decreased.