×

Rotational vibration detection using spindle motor velocity sense coils

  • US 6,222,336 B1
  • Filed: 04/30/1999
  • Issued: 04/24/2001
  • Est. Priority Date: 06/05/1998
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for detecting application of rotational vibration to a disc drive having a spindle motor with a driver coil and a driver magnet, the spindle motor rotating a data storage disc through controlled application of current to the driver coil to establish a magnetic field which interacts with a magnetic field generated by the permanent magnet, the method comprising steps of:

  • (a) immersing a velocity sense coil in a magnetic field generated by a permanent magnet of the spindle motor;

    (b) generating a motor velocity signal indicative of a rotational velocity of the disc in relation to a voltage induced across the velocity sense coil by relative movement between the velocity sense coil and the magnetic field of the immersing step (a); and

    (c) detecting application of rotational vibration to the disc drive in relation to the motor velocity signal.

View all claims
  • 8 Assignments
Timeline View
Assignment View
    ×
    ×