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Magnetic-type information card and method and apparatus for encoding and reading

  • US 4,058,839 A
  • Filed: 09/03/1974
  • Issued: 11/15/1977
  • Est. Priority Date: 08/21/1974
  • Status: Expired due to Term
First Claim
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1. A flexible resilient magnetic particle type information card capable of correctly reading information thereon after such card has been bent back double on itself and creased at the region of the card that includes the magnetic particles, said card comprising a flexible base, a layer of uniformly distributed magnetic particles thereon, and a flexible overlayer of nonmagnetic material, said overlayer having a thickness of at least 2 mils, said layer of magnetic particles being magnetically digitally encoded, consecutive equal portions of said layer having one polarity of magnetic flux or the opposite polarity, with abrupt magnetic flux transitions between oppositely polarized portions, the magnetic flux transitions of such encoding being at least 0.02 inch apart and said magnetic particle layer being enclosed between the base layer and overlayer and spaced from the edges of the card.

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