Between a spatial beam modulator for modulating an object beam and a one-dimensional
diffuser plate for diffusing the object beam modulated by the spatial beam modulator
in a one-dimensional direction, there is arranged an object projection optical
system for processing the object beam modulated by the spatial beam modulator in
such a manner that, in the one-dimensional direction of the one-dimensional diffuser
plate, images displayed by the spatial beam modulator are formed on the one-dimensional
diffuser plate, and, in a direction substantially orthogonal to the one-dimensional
direction, the object beam is condensed onto a hologram recording medium. In the
one-dimensional direction of the one-dimensional diffuser plate, the images displayed
by the spatial beam modulator are formed on the one-dimensional diffuser plate,
whereby blurring of the images with the one-dimensional direction as a non-parallactic
direction can be suppressed.