Access control device

Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

369 4432, 369 4428, 369 4425, G11B 700

Patent

active

054426049

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.

REFERENCES:
patent: 4669074 (1987-05-01), Hsieh et al.
patent: 4785439 (1988-11-01), Okada et al.
patent: 4951272 (1990-08-01), Wachi et al.
patent: 5003524 (1991-04-01), Ikeda
patent: 5077716 (1991-12-01), Takeda et al.
patent: 5087997 (1992-02-01), Osada et al.
patent: 5090001 (1992-02-01), Ito et al.
patent: 5101386 (1992-03-01), Kojima et al.
patent: 5117410 (1992-05-01), Akiyama
patent: 5249168 (1993-09-01), Kagami et al.
Excerpt from chapter 1 "Optical Disk Drive"; pp. 160-161, published Feb. 10, 1989.
Excerpt from "CXA1082BQ/BS"; pp. 174-175 published Mar. 1991.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Access control device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Access control device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Access control device will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2188099

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.