Information recording/reproducing apparatus, apparatus for manufacturing optical information recording medium, and optical information recording medium

摘要

An optical information recording/reproducing apparatus equipped with a mechanism for moving an optical pickup to an arbitrary radial position of an optical information recording medium using holography. A total sum signal of signals is generated at the photodetector for receiving signals reproduced from the optical information recording medium, and a radial position of the pickup is obtained from the number of pulses in the total sum signal to thereby allow the pickup to move to an arbitrary radial position.