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US 6,549,492 B1Granted
Method and apparatus for run-out correction in a disk drive
AssigneeOak Technology, Inc.
InventorHubert Song
Life of this patent
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Abstract
To correct for run-out in an optical disk drive, a run-out reducing gain factor is selected. A run-out correction signal is produced by applying the run-out reducing gain factor to a center error signal. A servo drive signal is refined with the run-out correction signal to produce an adjusted servo drive signal. A tracking actuator is driven with the adjusted servo drive signal.
Claims8
A disk drive comprising:
- a spindle motor to rotate a disk;
- a head to read information from said disk and generate read signals;
- a tracking actuator, responsive to a servo drive signal, to position said head with respect to said disk;
- a sled coupled to said tracking actuator and said head, also to position said head with respect to said disk;
- a preamplifier to generate a center error signal from said read signals;
- a high pass filter to generate a filtered center error signal by removing at least a DC component in said center error signal;
- a memory that stores a sampled center error signal;
- a switching mechanism to select between said sampled center error signal and said filtered center error signal to be sent to a multiplier;
- wherein said multiplier multiplies said selected center error signal by a run-out reducing gain factor to produce a run-out correction signal;
- and
- a summer that adds said run-out correction signal to a selected servo drive signal to produce an adjusted servo drive signal that is supplied to said tracking actuator.
8 more elements
An apparatus for correcting for run-out in an optical disk drive comprising:
- a preamplifier to generate a center error signal;
- a high pass filter to generate a filtered center error signal by removing at least a DC component in said center error signal;
- a memory that stores a sampled center error signal;
- a switching mechanism to select between said sampled center error signal and said filtered center error signal to be sent to a multiplier;
- wherein said multiplier multiplies said selected center error signal by a run-out reducing gain factor to produce a run-out correction signal;
- and
- a summer that adds said run-out correction signal to a selected servo drive signal to produce an adjusted servo drive signal that is supplied to a tracking actuator.
4 more elements
Dependencies are inferred from the claim text.