Patent ID: 7626911

Claim:
A hologram reproduction apparatus wherein reproduction reference light is irradiated upon a hologram recording medium, on which data are multiple recorded in accordance with an angle multiple method, while the incidence angle of the reproduction reference light to the hologram recording medium is varied and reproduction light generated from the hologram recording medium thereupon is received by an image pickup apparatus, by which the multiple data are demultiplexed from the reproduction light and reproduced, comprising: an unnecessary light removal section configured to remove unnecessary light of the reception light to allow only necessary light included in the reproduction light to be received by said image pickup apparatus; a drive section configured to move the hologram recording medium or an optical system provided for introducing the reproduction reference light to the hologram recording medium; an optical detection section configured to detect a projection state of the unnecessary light removed by said unnecessary light removal section to said unnecessary light removal section; and a control section configured to detect a positional displacement of the hologram recording medium based on particular information from within information relating to the detected projection state and control said drive section to move the hologram recording medium or said optical system so as to eliminate the detected positional displacement.