Focusing servo controlling apparatus

摘要

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.