Hologram in which a plurality of areas are set and holography system to which hologram is applied

摘要

A hologram (10) is formed using a grating (11) and a second hologram (12) serving as an image hologram. The grating (11) is constituted by a plurality of areas whose spatial frequencies and diffraction directions are different from each other. This grating (11) is formed using a grating array (13) and a mask (14). The second hologram (12) has a plurality of areas each of which records information or image (e.g., ID data) serving as a recording target as an element hologram. The second hologram (12) is formed using a Fresnel hologram serving as a first hologram (15). The first hologram (15) can also be formed using a mask (17) and a diffuser (16) on which ID data is projected. On the hologram (10), information (pattern or image) is recorded with each of reference light components having different directions corresponding to the different small areas. Even if illumination light having a uniform wavefront is irradiated on this hologram, it is difficult to detect all the information (pattern and image). $$