Patent ID: 6490061
Filing Date: 2002-12-03
Classification: G03H,G11B,G11C

Abstract:
An optical information recording and reproducing apparatus, said apparatus comprising:a holographic memory, including a plurality of pages, made of a photorefractive crystalline material; a support portion for detachably supporting said holographic memory; a reference beam supplying portion for supplying a coherent reference beam of a first wavelength incident on said holographic memory; a signal beam generating portion for supplying a coherent signal beam of the first wavelength, which is modulated in accordance with image data, incident on said holographic memory, intersecting therein said signal beam with said reference beam, and for generating a light interference pattern of said signal beam and said reference beam; a detecting portion for detecting a diffracted light from a refractive index grating of the light interference pattern in said holographic memory, due to irradiation of said reference beam and a medium position adjusting portion for moving a position of said support portion, which supports said holographic memory, in accordance with a signal corresponding to a positioning image from said detecting portion, wherein said holographic memory includes a nonvolatile refractive index grating corresponding to a light interference pattern of a coherent reference beam and a coherent signal beam, said coherent signal beam is modulated in accordance with the positioning image, and the positioning image and the image data are recorded on different pages.