Focusing servo controlling apparatus
AssigneeSony Corporation
InventorsSumihiro Okawa, Takayasu Muto, Shuji Uehara
Life of this patent
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Abstract
A magneto-optical disc recording or reproducing device focusing control servo system which uses a digital signal processor (DSP) to control a pulse width modulation (PWM) circuit so that if the focusing servo is to be in operation alone, such as during a focusing search or seek, fixed clocks of a fixed frequency are used for processing focusing servo signals and after engagement of the focusing servo, focusing servo is effected responsive to focusing servo signals which are formed based upon a reproduced servo pattern of the magneto-optical disc.
Claims7
A recording/reproducing apparatus for recording and reproducing signals recorded on an optical disc, comprising;
- a servo operated at least by focusing servo signals and tracking servo signals;
- a servo signal processing device in which at least the tracking servo signal and the focusing servo signals are formed, based upon playback output of a plurality of pre-set patterns intermittently reproduced from the optical disc on which the servo patterns are arrayed at pre-set intervals, and said tracking servo signals are outputted at a first pre-set timing followed by the focusing servo signals at a pre-set timing;
- and
- output timing control means for controlling an output timing of the focusing servo signal so that, when a focusing servo operation is effected by itself, the output timing is prompted at a third per-set timing for outputting only the focusing servo signals, wherein third pre-set timing is less than said first pre-set timing and less than said second pre-set timing.
Dependencies are inferred from the claim text.