Title:
INDEX SERVO SYSTEM
Document Type and Number:
Japanese Patent JPS63127479
Kind Code:
A
Abstract:
PURPOSE:To enable an exact track follow operation against a disturbance such as a temperature change, etc., by determining a sampling interval according to a difference value between an offset quantity at the time of the sampling of this time and the offset quantity at the time of the sampling of a previous time. CONSTITUTION:The sampling of servo information is performed in such a way that an index servo control circuit 6 shifts a head 2a to a track, on which the servo information is recorded, by an instruction from a sampling interval determining means 5, and a servo information detecting means 7 detects the servo information at that time. At every sampling, the servo information of the circuit 6 is updated. Then, for instance, the offset quantity A, detected at the time t0, is stored, as the value of the previous time, in a previous offset quantity register 4, and is compared with the offset quantity B, detected at the next time t1, by a sampling interval determining means 5. As the result of this comparison, if the absolute value of A-B is larger than a prescribed value, the sampling time is shortened, and the increase of an off-track quantity at the vicinity of the next time t2 is prevented.
More Like This:
Inventors:
SAITO SHIGEO
MIMA SHOJI
MIMA SHOJI
Application Number:
JP27342486A
Publication Date:
May 31, 1988
Filing Date:
November 17, 1986
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
G05B21/02; G05D3/12; G11B21/10; (IPC1-7): G05B21/02; G05D3/12; G11B21/10
Attorney, Agent or Firm:
Sadaichi Igita