Title:
POSITION SIGNAL DEMODULATOR OF DISK DEVICE
Document Type and Number:
Japanese Patent JPS5938977
Kind Code:
A
Abstract:
PURPOSE:To improve the track following stability and to eliminate the dependence on a cylinder for a position modulator, by equalizing position sensitivity on both inner and outer circumferences of the cylinder. CONSTITUTION:A compensator 9 is provided to a position signal demodulator 8, and a servo signal 7 is read out of a servo surface 5 of a disk 4 by a servo head 6. A position signal is demodulated by the demodulator 8, and the compensator 9 works to obtain the fixed position sensitivity. Then the compensated position signal is fed to a detector 10 to obtain a speed signal. In accordance with this speed signal, a driving mechanism part 12 is controlled by a control circuit 11 to position the head 6. An analog switch 14 is switched by the compensator 9 in response to a cylinder address extracted from a register 13 which varies the shift of the head 6. Thus the gain of an operational amplifier 15 is increased or decreased to compensate a position signal 16 having different position sensitivities between inner and outer cylinders. Then a position signal 17 having constant position sensitivity is obtained.
Inventors:
TSUTSUI TADAHIKO
SAKUMA MASASHI
NAKABAYASHI KAZUYOSHI
SAKUMA MASASHI
NAKABAYASHI KAZUYOSHI
Application Number:
JP14752982A
Publication Date:
March 03, 1984
Filing Date:
August 27, 1982
Export Citation:
Assignee:
HITACHI LTD
HITACHI ELECTR ENG
HITACHI ELECTR ENG
International Classes:
G11B21/08; G11B21/10; (IPC1-7): G11B21/10
Attorney, Agent or Firm:
Toshiyuki Usuda