Masking of tracking error signal abnormalities due to media defects

Abstract

In an optical disk recorder, during the sensing of closely-spaced, position-indicating, machine-sensible indicia, a first peak of a track error signal is detected. In response to the first peak being detected, a half-track counter is decremented from a value which depends upon the position of the destination track relative to a current track. In response to the occurrence of a selected value of the half-track counter and the presence of a zero crossing of the tracking error signal, a first timer is activated to mask any defects occurring during the selected first half cycle of the last cycle of the tracking error signal. The half-track counter is again decremented in response to a second peak being detected and the occurrence of a next-to-last zero crossing of the tracking error signal and a second timer is then activated to mask any subsequent defects occurring during the second half cycle of the tracking error signal. The seek operation is terminated when the count value in the half-track counter equals zero and a final zero crossing is detected. Thereafter, a track following operation is activated.