US 2010/0149695 A1 · HEAD ACTUATOR VELOCITY CONTROL FOR ELECTRICAL POWER OFF IN A DISK DRIVE

Abstract

A hard disk drive with a voice coil motor coupled to a head. The head is coupled to a disk that is rotated by a spindle motor. The spindle motor generates a back-emf current. The disk drive also includes a drive circuit that causes the voice coil motor to move the head off of the disk. The drive circuit provides at least a portion of the back-emf voltage to the voice coil motor if a head velocity exceeds a first predetermined value and a larger portion of the back-emf voltage if the head velocity exceeds a second predetermined value. For example, a relatively small amount of voltage can be provided if the head velocity falls below a first threshold to accelerate the head and a larger current can be provided if the head velocity falls below a lower threshold to generate a greater head thrust.

Claims20

Dependent claims

A hard disk drive, comprising:

a disk;
a spindle motor that rotates said disk and generates a back-emf voltage;
a head coupled to said disk;
an actuator arm coupled to said head;
a voice coil motor coupled to said actuator arm;
and,
a drive circuit that causes said voice coil motor to move said head off of said disk, said drive circuit provides at least a portion of said back-emf voltage to said voice coil motor if a head velocity exceeds a first predetermined value and a larger portion of said back-emf voltage if said head velocity exceeds a second predetermined value.

4 more elements

Dependencies are inferred from the claim text.

Head actuator velocity control for electrical power off in a disk drive

Life of this patent

Head actuator velocity control for electrical power off in a disk drive

Life of this patent

Abstract

Claims20