METHOD FOR MEASURING SHAKING OF HOLOGRAPHIC DIGITAL STORAGE SYSTEM

摘要

PURPOSE: A method for measuring shaking of a holographic digital storage system is provided to correct shaking based on shaking information measured by setting a shaking track and using a reference pattern, thereby preventing the quality of an image from lowering. CONSTITUTION: A disk type storage medium(10) has a reference shaking track recording each reference beam(51,57) and signal beam(53,55) having the same diffraction rate at a plurality of places. A beam generating unit reproduces one beam at an angle of the reference beam in forming a pattern of the reference shaking track. The beam generating unit reproduces the other beam rotating from an angle of the recorded signal beam to a predetermined angle to enter beams for measuring shaking to the plurality of places of the reference shaking track respectively. A plurality of photo detectors(63,65) are placed on extended lines of the signal beams entered the disk type storage medium for sensing power of the beams. A microprocessor(40) compares power values and calculates a degree of shaking of the disk type storage medium by using the result of the comparison and the angular selectivity.