Signal reproducing method and storage apparatus
AssigneeFujitsu Limited
InventorTomoaki Saito
Life of this patent
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Abstract
A signal reproducing method reproduces servo information recorded on a recording medium by use of a head. A current calculation related to a current and an observer calculation related to a position and a velocity of the head are made based on reproduced servo information, and a current value for driving the head is calculated based on the above calculation result. Only computations which require a demodulation result of a present sample are made during a first time after demodulation of the position of the head to a time when the current value is output, and computations which require a demodulation result of a past sample are made during a second time other than the first time.
Claims8
A signal reproducing method for reproducing servo information recorded on a recording medium by use of a head, comprising the steps of:
- (a) carrying out a current calculation related to a current, and an observer calculation related to a position and a velocity of the head, based on reproduced servo information;
- and
- (b) calculating a current value for driving the head, based on a calculation result of the step (a),
- said step (b) carrying out only computations which require a demodulation result of a present sample during a first time after demodulation of the position of the head to a time when the current value is output, and carrying out computations which require a demodulation result of a past sample during a second time other than the first time.
A storage apparatus comprising:
- reproducing means for reproducing servo information recorded on a recording medium by use of a head;
- matrix calculation means for carrying out a current calculation related to a current, and an observer calculation related to a position and a velocity of the head, based on reproduced servo information;
- and
- filter calculation means for calculating a current value for driving the head, based on a calculation result of said matrix calculation means,
- said filter calculating means carrying out only computations which require a demodulation result of a present sample during a first time after demodulation of the position of the head to a time when the current value is output, and carrying out computations which require a demodulation result of a past sample during a second time other than the first time.
Dependencies are inferred from the claim text.