Identification article with pattern-form fresnel hologram, fabrication thereof, and verification thereof

A process for producing an identification article comprising a substrate structure and a pattern-form identification information providing layer which contains both visual identification information and latent holographic information, said process comprising the steps of:

• (a) forming on the surface of a photosensitive resin a latent image of a Fresnel hologram by exposing a photosensitive resin layer of a photosensitive base plate to an interference light obtained by causing interference between an object light beam and a reference light beam, both light beams being derived from a single coherent light beam divided into first and second coherent light beams, said object light beam being obtained by at least one of passing said first coherent light beam through a diffusion plate and a transmissive pattern and causing it to be reflected by a reflective pattern, said reference light beam being said second coherent light beam;
• (b) exposing the Fresnel hologram thus obtained to ultraviolet light transmitted through a mask pattern, said photosensitive resin being at least one of a positive type photoresist and a negative type photoresist;
• and
• (c) fabricating said information providing layer by developing said Fresnel hologram, said visual identification information being conveyed by a pattern being formed of a first portion and a second portion, said first portion having fine concavities and convexities on the surface thereof and said second portion being essentially smooth, said Fresnel hologram being contained on said first portion of the information providing layer, one of said first and second portions displaying said visual identification information, and the other of said first and second portions forming a background for said visual identification information.