Patent ID: 7852538

Claim:
A hologram recording apparatus for recording, on a hologram recording medium by an angle multiplex system, an interference fringe generated by interference between a signal beam and a reference beam varied in an angle of incidence with respect to a normal to the surface of said hologram recording medium, on said hologram recording medium, comprising: an irradiation range fixing section configured to regulate a beam diameter of the reference beam based on the angle of incidence of the reference beam with respect to the normal to the surface of said hologram recording medium, such that changes in a range of irradiation of said hologram recording medium with said reference beam as the angle of incidence of the reference beam with respect to the normal to the surface of said hologram recording medium is varied are offset, and the range of irradiation of said hologram recording medium with said reference beam is maintained substantially constant, the irradiation range fixing section being configured to change a ratio between a length of a major axis of the reference beam and a length of a minor axis of the reference beam to regulate the beam diameter, wherein the irradiation range fixing section is configured to maintain the length of the minor axis of the reference beam at a fixed length.