Holographic-stereogram-forming apparatus, diffusing member, and holographic-stereogram-forming method

A holographic-stereogram-forming apparatus comprising:

• a laser beam source that generates a laser beam to be split into an object beam and a reference beam, the object beam being applied to a hologram recording medium;
• a display that displays an original image corresponding to a substantially strip-shaped holographic element constituting a holographic stereogram containing parallax information in a horizontal direction;
• a diffusing unit provided on a light-emission side of the display and including a plurality of optical elements having different thicknesses in a direction of light transmission, the optical elements being arranged side by side in the horizontal direction and in a vertical direction in a matrix, the optical elements each having a substantially rectangular shape with a vertical length being shorter than a horizontal length, the diffusing unit diffusing the object beam more widely in the vertical direction than in the horizontal direction, the object beam to be diffused by the diffusing unit being generated by the display;
• and
• a condensing unit that condenses the object beam diffused by the diffusing unit on the hologram recording medium.