| 摘要 |
<p>An optical-disk drive apparatus wherein a carriage (4) on which a tracking actuator (6) and a photosensor unit (7) are mounted is driven by a linear actuator (5), to move the spot of the light beam (2) in a direction of traversing the tracks, and to detect a first position signal and a second position signal indicative of a position of the spot on the tracks through addition and subtraction of the electric signals corresponding to changes of the quantities of the reflected light attendant upon the movement. The apparatus comprises first waveshaping means (30) for causing a half wave greater and a half wave smaller than an arithmetic mean value of maximum and minimum values of an oscillating waveform of the first position signal to correspond to a single square pulse and a zero output as to each cycle, respectively and for converting them into a first shaped position signal delayed for a predetermined time (T), and second waveshaping means (40) for causing a half wave greater and a half wave smaller than an arithmetic mean value of maximum and minimum values of an oscillating waveform of the second position signal to correspond to a single square pulse and a zero output as to each cycle, respectively, and for converting them into a second shaped position signal delayed for a predetermined time (T).</p> |
