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APPARATUS FOR TESTING A CREDIT CARD

  • US 3,795,805 A
  • Filed: 05/18/1973
  • Issued: 03/05/1974
  • Est. Priority Date: 05/18/1973
  • Status: Expired due to Term
First Claim
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1. Apparatus for testing the authenticity of a credit card having a layer of a substance with a first optical reflectance characteristic when within a first temperature range, and a second optical reflectance characteristic when heated to a temperature beyond said first temperature range, comprising:

  • first means for heating said substance through at least a portion of said first temperature ranGe and thereafter to beyond said first temperature range, second means for projecting a high intensity beam of light onto said substance, a plurality of photoelectric assemblies positioned adjacent said substance, each of said photoelectric assemblies responsive to electromagnetic radiation of a different frequency reflected by said substance, a plurality of networks, each including a component of said photoelectric assemblies, for transforming the electromagnetic radiation of said different frequencies to time-amplitude varying electrical signals, and logic means coupled to said networks for determining if said time-amplitude varying electrical signals are within desired amplitude ranges when said substance is heated through said first temperature range and beyond said first temperature range.

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