Average servo control method and system, and target level determination method applied in thereof
AssigneeMediatek Inc.
InventorPo-Wei Chang
Life of this patent
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Abstract
An average servo control method is provided. A target level of at least a servo signal is first detected, which is corresponding to a present condition of the optical disc drive. The target level is then compared with a current level of the servo signal, and a average servo loop gain is adjusted based on the comparison result. A target level calibration may be performed before the gain adjustment. The target level calibration analyzes the servo signal to determine a plurality of preset target levels each corresponding to a different condition. The preset target levels and corresponding conditions are stored as a lookup table. In this way, the target level is acquired based on the lookup table and the present condition.
Claims17
An average servo control method of an optical disc drive which has a plurality of photo detectors, comprising:
- receiving at least a servo signal via an average servo loop;
- determining a target level of the servo signal corresponding to a present condition of the optical disc drive;
- comparing the target level and a current level of the servo signal;
- and
- adjusting an average servo loop gain based on a difference between the target level and the current level;
- wherein the servo signal is detected by the plurality of photo detectors, and each photo detector has a corresponding gain partially contributed to the servo signal, and wherein an average servo gain being controlled is selected from a group comprising:
- a gain for amplifying the servo signal and a gain for amplifying a detecting portion of the servo signal.
A target level determination method for determining a target level of a servo signal generated by an average servo loop of an optical disc drive, the target level determination method comprising:
- determining a present condition of the optical disc drive;
- calculating the target level according to the present condition;
- performing a target level calibration based on the servo signal to determine a plurality of preset target levels each corresponding to a different condition;
- and
- storing the preset target levels and corresponding conditions as a lookup table.
An average servo control system of an optical disc drive having an average servo loop for generating at least a servo signal, the optical disc drive has a plurality of photo detectors, each photo detector has a corresponding gain partially contributed to the servo signal, the average servo control system comprising:
- a level determining module for determining a target level of the servo signal corresponding to a present condition of the optical disc drive;
- a comparing module for comparing the target level and a current level of the servo signal;
- and
- a gain adjusting module for adjusting an average servo gain based on a difference between the target level and the current level;
- wherein the average servo gain is selected from a group comprising:
- a gain for amplifying the servo signal and a gain for amplifying a detecting portion of the servo signal.
Dependencies are inferred from the claim text.