Hologram reproduction apparatus and hologram reproduction method

A hologram reproduction method for 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:

• a removal step of removing unnecessary light included in the reception light to allow only necessary light included in the reproduction light to be received by said image pickup apparatus;
• a step of detecting a projection state of the removed light and detecting a positional displacement of the hologram recording medium based on particular information from within information relating to the detected projection state;
• and
• a step of moving the hologram recording medium or an optical system provided for introducing the reproduction reference light to the hologram recording medium so as to eliminate the detected positional displacement.

A hologram reproduction method for 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 the steps of:

• detecting part of the reproduction light:
• detecting a positional displacement of the hologram recording medium based on particular information from within information relating to the detected reproduction light:
• and
• moving the hologram recording medium or an optical system provided for introducing the reproduction reference light to the hologram recording medium so as to eliminate the positional displacement,
• wherein the particular information is derived from that portion of the reproduction light, projected on a baffle which passes part of the reproduction light therethrough, which is on an outer periphery around 0th order light of the reproduction light generated from a recording area of a reproduction target on the hologram recording medium and which is on the inner side of the projection region of the reproduction light generated from a recording area adjacent the reproduction area of the reproduction target.