| 摘要 |
PURPOSE:To produce easily a pattern-shaped Fresnel hologram which is difficult to forge and is easily distinguished from false holograms and is superior in decorativity, by providing a pattern-shaped Fresnel hologram. CONSTITUTION:A photosensitive substrate exposed to an interference light is exposed to a light 9 for exposure through a mask pattern 8. Though a proper light-transmissive pattern can be used as the mask pattern, a pattern matched not to damage the transmission pattern is desirable. Ultraviolet rays, especially, rays having 0.25-0.45mum wavelength emitted from a light source such as an extra-high pressure mercury vapor lamp, a high pressure mercury vapor lamp, a low pressure mercury vapor lamp, a carbon arc, a xenon arc, or the like are used desirably as the light 9 for exposure, and it is desirable that irradiation is so performed that the integral exposure is >=10mJ/cm<2>. By this exposure through the mask pattern, a photosensitive resin layer in parts exposed to light is decomposed when the photosensitive resin layer is positive, and this photosensitive resin layer in these parts is hardened when the photosensitive resin layer is negative, and the pattern-shaped Fresnel hologram is obtained by the development using a developer. |
