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US 5,703,849 AGranted
Tracking servo correction control circuit
AssigneeSony Corporation
InventorHidenobu Noda
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AssigneeSony Corporation
InventorHidenobu Noda
Estimating the term…
In a tracking servo circuit for such as an optical disc device, and the like, a tracking error signal TE obtained in a servo-off state is subjected to A/D conversion, the center level thereof is calculated at a center level computation circuit, that value is stored in a register, at a time of servo-on, switches are connected to one terminal side, in the normal operation mode, the center level stored in the register is subtracted from the tracking error signal TE obtained at the time of the servo-on state at the subtraction circuit, the offset of the tracking error signal is corrected, and when light reflected from the surface of the disc can no longer be obtained due to an accidental cause, the connection of another switch is switched to the terminal b in response to the switching of the signal FOK generated based on the RF signal to the low level, and the offset correction operation of the tracking error signal TE is stopped.
A tracking servo circuit which obtains a drive output for correction of the position of the light irradiated on the surface of a recording medium by a tracking error signal obtained in accordance with the level of reflection of light irradiated to the surface of the medium, comprising:
A tracking servo circuit which obtains a drive output for correction of the position of the light irradiated on the surface of a recording medium by a tracking error signal obtained in accordance with the level of reflection of light irradiated to the surface of the medium, comprising:
Dependencies are inferred from the claim text.