Optical information recording and/or reproducing apparatus provided with means for detecting on-track/off-track signal by holding peak value and bottom value

摘要

An optical information recording and/or reproducing apparatus includes an optical head for recording and/or reproducing information by applying a light beam to an optical recording medium having a plurality of tracks, an actuator for relatively moving the light beam in a direction which intersects the tracks, an optical detector for detecting, by intersecting the tracks, a reflected or transmitted light of the light beam, which has been modulated, a peak holding circuit for holding a peak value of a signal detected by the optical detector, a bottom holding circuit for holding a bottom value of the detected signal, a circuit for obtaining an intermediate value of the held peak value and bottom value, and a comparison circuit for transmitting an on-track/off-track signal by making a comparison between the intermediate value and the detected signal.