Patent ID: 7079469

Claim:
A hologram recording and reproducing system comprising: a supporting unit for freely attachably supporting a recording medium including a photosensitive material; a signal light-generating unit for projecting a coherent light beam modulated according to a predetermined data into the recording medium and generating a diffraction grating by providing a three-dimensional light interference pattern in the recording medium; a detector unit for detecting and photoelectrically converting a diffracted light from the diffraction grating; and a demodulating unit for demodulating a predetermined data from an output from the detector unit, the hologram recording and reproducing system characterized in that: the detector unit has an intermediate data-generating unit for generating an intermediate data, and the demodulating unit has a conversion table in which the intermediate data and the predetermined data are uniquely associated, and demodulates the predetermined data by performing an operation based on a correlation in the conversion table, and in that: at the time of recording of the hologram recording and reproducing system, the predetermined data of image is recorded in the recording medium as the interference pattern of Fourier transformed pattern formed with an optical system, and at the time of reproducing, inverse Fourier transform is performed by the detector unit and the demodulating unit to reproduce the predetermined data of image.