Patent ID: 7796313

Claim:
A process for effecting at least one of recording of information on and reproducing of information from a reflection-type holographic information recording medium, which includes a reflecting layer, said process comprising: (a) for effecting recording of information on the recording medium: (i) branching a light beam from a light source into a first branched light beam and a second branched light beam; (ii) forming an information light beam from the first branched light beam by modulation with a spatial light modulation element; and (iii) recording the information by forming an interference fringe by projecting the second branched light beam as a recording reference light beam together with the information light beam onto the reflection type recording medium; and (b) for effecting reproducing of information from the recording medium: (i) projecting a light beam from the light source as a reproducing reference light beam onto the interference fringe, wherein an angle of incidence of the recording reference light beam into the interference fringe and an angle of incidence of the reproducing reference light beam into the interference fringe are one hundred eighty degrees from one another.