Method of ramp stop detection for VCM velocity-controlled retract
AssigneeMarvell International Ltd.
InventorsSiew Yong Chui, Edy Susanto, Jye Sheng Hong
Life of this patent
Estimating the term…
Abstract
A method and apparatus for controlling the parking of a transducer head in a disk drive. A drive current is provided to a motor which controls movement of the head in a direction to move the head to a parking position. The arrival of the head at the parking position is detected. Upon this detection, a drive stop sequence is initiated to stop providing the drive current a short time after the head reaches the parking position. In one embodiment, it is determined whether the head has reached the parking position by monitoring the back emf (bemf) of the motor controlling the head, typically a voice coil motor (VCM). The detection of a sharp decline in the bemf indicates the head has stopped.
Claims20
A method for controlling movement of a head in a disk drive comprising:
- positioning the head at any of a plurality of positions;
- providing drive current to a motor after positioning the head;
- detecting information indicative of a position of the head after the drive current has been provided to the motor, the motor controlling the movement of the head;
- and
- generating a command that controls the movement of the head in response to the detected information.
A method for controlling movement of a head in a disk drive comprising:
- positioning the head at any of a plurality of positions;
- providing drive current to a motor after positioning the head;
- monitoring a back emf of the motor controlling the movement of the head;
- detecting information indicative of a position of the head after the drive current has been provided to the motor based on detecting a change in the back emf;
- and
- generating a command that controls the movement of the head in response to the detected information.
An apparatus for controlling movement of a head in a disk drive comprising:
- a motor positioning the head at any of a plurality of positions;
- a driver proving drive current to a motor after positioning the head;
- a detector detecting information indicative of a position of the head after the drive current has been provided to the motor, the motor controlling the movement of the head;
- and
- a controller, responsive to the information detected by the detector, that generates a command that controls the movement of the head.
An apparatus for controlling movement of a head in a disk drive comprising:
- a motor positioning the head at any of a plurality of positions;
- a driver providing drive current to the motor after positioning the head;
- a back emf monitor that monitors a back emf of the motor, the motor controlling the movement of the head;
- a detector that detects information indicative of a position of the head after the drive current has been provided to the motor, the detector detecting the information based on detecting a change in the back emf;
- and
- a controller, responsive to the information detected by the detector, that generates a command that controls the movement of the head.
Dependencies are inferred from the claim text.