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Secure property document and system

  • US 4,013,894 A
  • Filed: 05/27/1975
  • Issued: 03/22/1977
  • Est. Priority Date: 05/27/1975
  • Status: Expired due to Term
First Claim
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1. A secure property for an article in a group of authentic articles for preventing certain alterations or duplication of the article, said secure property comprising:

  • at least two sets of data carried by said article, each said data set containing at least one data element which has a spacial relationship to at least one data element of the other data set,one of said data sets containing informational data to be rendered secure by said secure property and being substantially different than the data of said other data set,said spacial relationship between said data set elements being substantially unique to said article within said group of authentic articles whereby the authenticity of said article may be determined,one of said data sets comprising means including a plurality of radiant energy modifying elements for providing data in the form of detectable radiant energy signals in response to irradiation with radiant energy of appropriate characteristics, the other of said data sets comprising magnetic data including a plurality of magnetic flux changes at least some of which are randomly spaced within limits from at least some of said radiant energy modifying elements.

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