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Secure optical identification means and method with enhanced variability

  • US 5,793,502 A
  • Filed: 01/29/1996
  • Issued: 08/11/1998
  • Est. Priority Date: 08/31/1993
  • Status: Expired due to Fees
First Claim
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1. Secure optical identification means, comprising:

  • (a) a first lacquer layer;

    (b) a metallic layer disposed on a first surface of said first lacquer layer, with a first surface of said metallic layer in contact with said first surface of said first lacquer layer;

    (c) a diffraction pattern embossed in said first surface of said first lacquer layer through said metallic layer;

    (d) a pattern formed in said metallic layer by demetallizing areas of said metallic layer; and

    (e) a second lacquer layer, having the same refractive index as that of said first lacquer layer, disposed on a second surface of said metallic layer so as to fill in voids adjacent said diffraction pattern caused by said demetallizing areas of said metallic layer.

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