Title:
COSINE EQUALIZING SYSTEM
Document Type and Number:
Japanese Patent JPS6242368
Kind Code:
A
Abstract:
PURPOSE:To apply a waveform shaping by switching the constant of a cosine equalizing circuit in response to the change in the resolution and changing the constant respectively at the outside and inside of a disc. CONSTITUTION:The control voltage of an automatic gain amplifier 5 provided to plural heads enters the non-inverting terminal of an operational amplifier 4. A comparison voltage representing the position of a head to a disc is determined in advance corresponding to the control voltage and fed to the inverting terminal of the operational amplifier 4 from a terminal A. The resolution is deteriorated sequentially as the head moves from the outside of the disc to the inside. When the control voltage of the automatic gain amplifier 5 is higher than the compared voltage, the operational amplifier drives a switch 3, and e.g., a contact is opened. Thus, a resistor R3 connected in parallel with a resistor R2 is removed, the constant (k) is switched at this point of time and when the head reaches the predetermined position of the disc, the operational amplifier 2 applies equalization with a different constant from the outside and inside of the disc.
Inventors:
KANEE MASAHIDE
Application Number:
JP18124385A
Publication Date:
February 24, 1987
Filing Date:
August 19, 1985
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
H03H11/04; G11B20/10; (IPC1-7): G11B20/10; H03H11/04
Attorney, Agent or Firm:
Sadaichi Igita