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Document protection methods and products

  • US 5,788,285 A
  • Filed: 06/19/1996
  • Issued: 08/04/1998
  • Est. Priority Date: 06/13/1996
  • Status: Expired due to Fees
First Claim
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1. A press printed document which is counterfeit resistant to known electronical optical copiers and scanners, comprising a print surface;

  • a first indicia printed on at least a portion of the print surface and formed by a set of continuous lines of substantially uniform pitch throughout the first indicia;

    a second indicia printed on at least a portion of the print surface adjacent to the first indicia and formed by a set of broken lines of substantially uniform pitch throughout the second indicia, each broken line defined by a plurality of coaxial short line segments of substantially equal width and equal length and by spaces between the short line segments the spaces being of substantially equal length and each of which has a length within a range from about 10% to about 45% of the length of each of the short line segments;

    in which the continuous lines are at angles to the broken lines and in which the copiers and scanners substantially reproduce the first indicia but not the second indicia.

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