OPTICAL DISC PLAYER WITH FOCUS CONTROL DURING SEARCH MODE

摘要

This system is an optical disc reproducing system. The optical disc player optically records frequency modulation video signal or pulse modulation (PCM) audio signal which are linearly arranged on the record disc in the format of a number of small pits. The optical disc player consists of an optical pick-up device which includes an objective lens through which a light beam is focussed on the surface of the record disc. The pick-up device is shiftable, as a unit, in a radial direction of the record disc for determing the track to be scanned by the focussed beam. A focussing servo control is responsive to defocussing of the light beam at the record disc surface for moving the object lens in the direction to restore correct focus of the light beam.