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Method and a system for verifying authenticity safe against forgery

  • US 4,218,674 A
  • Filed: 04/20/1978
  • Issued: 08/19/1980
  • Est. Priority Date: 09/09/1975
  • Status: Expired due to Term
First Claim
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1. A system for verifying the authenticity safe against forgery of a document by comparison of binary output signals therefrom with binary output signals previously stored, said system comprising:

  • (1) a document having randomly dispersed fibers of a magnetic or magnetizable material embedded within at least part of the base material of said document in order to give said documents an imperfection pattern individual thereto, said fibers having magnetic properties different from said base material,(2) means for detecting said fibers in a predetermined measuring track over the surface of said document,(3) means to convert said detected random fibers into an asymetric analogous pulse train,(4) discriminator means for separating such pulses from said pulse train which have amplitudes exceeding a predetermined threshold value from pulses having smaller amplitudes than said level,(5) a converter for converting said first-mentioned pulses to a series of detected pulses,(6) means for producing a measuring start and stop signal defining the active scanning time period,(7) a timing means supplying timing pulses, said timing means being indicia on the surface of said document, and(8) means to coordinate said series of detected pulses and said timing pulses to produce a series of binary output signals, whereby a comparison will develop the indentity of said document.

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