METHOD FOR DISCRIMINATING AUTHENTICITY OF RAINBOW HOLOGRAM AND INFORMATION RECORDING METHOD USING RAINBOW HOLOGRAM

摘要

PURPOSE: To discriminate the authenticity of a rainbow hologram even with (use of a simple device by recording the different type of information according to the position and the shape of a slit-shaped opening which functions to limit the object light used for the rainbow hologram recording. ;CONSTITUTION: A monochromatic rainbow hologram 1 is illuminated by the monochromatic light 2 at the incident angle 9. of the reference light used for the recording of the second stage. Thus θ₂ the slit image 4 of a recording state is reproduced by the diffraction light 3. When the rainbow holograms including the hologram 1 are reproduced, the light 2 of the reproduction wavelength λ' having the specific relation with the wavelength λ of the recording state is used. Then the hologram 1 is illuminated at an incident angle θ₂ having the specific relation with the angle θ₂. Thus the image 4 is reproduced. A detector means like a CCD camera, etc., checks whether the image 4 is reproduced in a prescribed shape and at a the hologram 1 is decided.;COPYRIGHT: (C)1993,JPO&Japio