Patent ID: 7061852

Claim:
A recording apparatus for a holographic recording medium having an alignment mark and designed to irradiate a recording light beam onto a recording region of holographic recording medium to record information as a hologram, the recording apparatus comprising: a recording laser irradiating the recording light beam for recording the hologram onto the holographic recording medium; a beam splitter splitting the recording light beam into two beams, one of which is utilized as a reference light beam; a spatial modulator providing information to the other beam obtained from the splitting to obtain a signal light beam; a first lens converging the reference light beam and directing the converged reference light beam toward the holographic recording medium; a second lens converging the signal light beam and directing the converged signal light beam toward the holographic recording medium; an alignment laser irradiating an alignment light beam perpendicularly onto the holographic recording medium, the alignment light beam being less absorbed than the recording light beam by the holographic recording medium, and being reflected by the holographic recording medium; a third lens converging the alignment light beam irradiated from the alignment laser and directing the alignment light beam toward the holographic recording medium; a photodetector detecting a light intensity of the alignment light beam reflected from the holographic recording medium to recognize the alignment mark; and a driving mechanism adjusting a region to be irradiated with the signal light beam and the reference light beam relative to the holographic recording medium on the basis of the alignment mark, wherein the signal light beam and the reference light beam are irradiated parallel with a track of the holographic recording medium to write an interference fringe in a direction perpendicular to the track of the recording region.