1. Field of the Invention
The invention relates to an information carrier and processes for producing an original copy of the carrier, which comprises a recording layer deposited on a carrier material. A relief image containing the information is embossed in the recording layer.
2. Description of the Prior Art
Images with grating-like screening have been produced by the ZOD (zero order diffraction) technique described in the LASER u. Elecktro-Optik Journal No. 3/1976, pages 16-17. Three nickel matrices are produced from the relief images which correspond, for example, to three primary-color grating patterns in a photoresist, and colorless thermoplastic films of, for example, polyvinyl chloride are embossed with these matrices. These films are mechanically superimposed, and, on projection with conventional projectors, colored projection images are obtained from the colorless relief images. The grating-shaped screening is effected with relief gratings of rectangular cross-section, the grating periods being approximately 1.5 .mu.m. A separate nickel matrix with different relief depths is made for each color separation (red, yellow and blue), from which separate embossed images are produced. The relief depths differ depending on the color separation. The greatest relief depths are used for the red color separation while the smallest are used for the blue color separation. The color separation images are screened. The embossed images are then superimposed to form a three-layered relief image which can be used to project colored images. The technique described yields very bright color images with high resolution. The relief images can be duplicated relatively cheaply and rapidly by an embossing process.
A disadvantage, which has hindered the introduction of this technique, is the expensive production process, incurred by performing three completely separate operations for producing the individual, embossed relief images, corresponding to the color separations. A further disadvantage ensues from the necessity of aligning the three separate relief images to form the duplicate image required for the colored projection.