Optical disc system with improved track jumping operation

Claim 1

An optical disc system having: tracking actuator means for positioning a light spot on an optical disc in a radial direction thereof; photodetector means for generating a trackigns ensor signal to detect off-track information with respect to the position of said light spot on said optical disc; circuit means for causing said tracking actuator means to jump said light spot from its present position on a track to a position on an adjacent track; acceleration pulse generating means for generating a signal to cause acceleration of said tracking actuator means during a track jumping operation; deceleration pulse generating means for generating a signal to cause deceleration of said tracking actuator means during said track jumping operation; and center detecting means for detecting when the said light spot is at the midpoint between adjacent tracks in response to a zero crossing point of said trackign sensor signal, said optical disc system characterized by including switching means responsive to an output signal of said center detecting means for switching control from said acceleration pulse means to said deceleration pulse means after a period of time has elapsed from the start of said track jumping operation, so that a false detection of the zero crossing point of said tracking sensor signal is prevented during said time period, signal level detecting circuit means responsive to said tracking sensor signal and having a detection level which is smaller than the level which corresponds to the maximum amplitude of said tracking sensor signal, whereby said time period is provided by the time period required for said tracking sensor signal to reach said detection level from the start of said track jumping operation.