Title:
OFFSET CORRECTING CIRCUIT
Document Type and Number:
Japanese Patent JPS61120385
Kind Code:
A
Abstract:
PURPOSE:To enter equivalently a state wherein no external force is applied substantially and to perform smooth seek control by flowing a necessary current to the coil of a VCM and canceling an external force applied to the movable part of the a VCM. CONSTITUTION:An offset signal OFST is applied to amplifiers 14, 16, and 18. Varous external forces applied to the movable part of the VCM are determined when a head position is fixed, so the external forces are calculated previously corresponding to respective projection lengths and stored in a ROM (read-only memory); and then the ROM is read according to the projection lengths to know the values of the external forces, which are corrected. A next cylinder address register 20 as a means for the correction is a register stored with the head position. Further, a ROM table 22 contains external forces corresponding to respective cylinder positions, concretely, offset values (current value) for canceling them. A digital/analog (D/A) converter 24 converts the readout output (digital value) of the ROM table 22 into an analog value to generate the offset signal OFST.
Inventors:
KONO KEIICHI
Application Number:
JP24134984A
Publication Date:
June 07, 1986
Filing Date:
November 15, 1984
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
G11B21/10; G11B21/08; G11B33/08; (IPC1-7): G11B21/10
Domestic Patent References:
| JPS57117162A | 1982-07-21 |
Attorney, Agent or Firm:
Fumihiro Hasegawa