SYSTEM FOR GENERATING REFERENCE BEAM ANGLE CONTROL SIGNAL AND HOLOGRAPHIC INFORMATION RECORDING AND/OR REPRODUCING APPARATUS APPLIED THE SAME

摘要

A system for generating a reference beam angle control signal and a holographic information recording and/or reproducing apparatus using the same are provided to control an angle of the reference beam without a loss of a signal beam optimally, and to generate an angle control signal simply through a signal processing part. A system for generating a reference beam angle control signal comprises first and second beam detectors(51,53), and a signal processing part(60). Books are formed by overlapping and recording signal beams resulting from two dimensional modulation in the same volume of a holographic medium(10). The beam detectors detect the signal beam reproduced from the first and second books adjacent to the predetermined book. The signal processing part obtains a reference beam angle control signal for controlling the projection angle of the reference beam by using a differential signal of the detection signal of the beam detectors. An opened member(40) has an opening(41) passing only the signal beam reproduced by the predetermined book.