Multiplex recording type hologram recording device, method, hologram reproduction device, and method

A multiple record type hologram reproduction apparatus comprising:

• a light source for irradiating a multiple record type hologram record medium with reproduction illumination light;
• a photoreceptor for receiving reproduction light based on the reproduction illumination light from the hologram record medium;
• a read device for reading record information recorded on the hologram record medium on the basis of the received reproduction light;
• a move device for moving a focus position of the reproduction illumination light relative to the hologram record medium in a direction along a surface of the hologram record medium;
• a parameter set device capable of changing and fixing a predetermined kind of parameter for multiple recording relating to the reproduction illumination light;
• and
• a control device for controlling said parameter set device to perform a reproduction by using the parameter used at the last reproduction at the m-th focus position (m is natural number) as the parameter for the first reproduction at the (m+1)-th focus position.

A multiple record type hologram record method of recording information to a hologram record medium in a multiple record type hologram record apparatus comprising:

• a light source for performing an irradiation with source light including signal light and reference light;
• a spatial light modulator disposed in an optical path of the signal light and capable of modulating the signal light;
• an optical system for introducing the signal light after passed through said spatial light modulator and the reference light onto the hologram record medium;
• a move device for moving a focus position of the signal light and the reference light introduced by said optical system, relative to the hologram record medium in a direction along a surface of the hologram record medium;
• and a parameter set device capable of changing and fixing a predetermined kind of parameter for multiple recording for at least one of the signal light and the reference light, the method comprising:
• a move process of moving the hologram record medium by the move device;
• and
• a control process of controlling the parameter set device to perform a recording by using the parameter used for the last recording at the m-th focus position (m is natural number) as the parameter for the first recording at the (m+1)-th focus position.

A multiple record type hologram reproduction method comprising:

• a light source for irradiating the multiple record type hologram record medium with reproduction illumination light;
• a photoreceptor for receiving reproduction light based on the reproduction illumination light from the hologram record medium;
• a read device for reading record information recorded on the hologram record medium on the basis of the received reproduction light;
• a move device for moving a focus position of the reproduction illumination light relative to the hologram record medium in a direction along a surface of the hologram record medium;
• and a parameter set device capable of changing and fixing a predetermined kind of parameter for multiple recording relating to the reproduction illumination light, the method comprising:
• a move process of moving the hologram record medium by the move device;
• and
• a control process of controlling the parameter set device to perform a reproduction by using the parameter used at the last reproduction at the m-th focus position (m is natural number) as the parameter for the first reproduction at the (m+1)-th focus position.