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Access control system where the card controls the transmission format of the card reader

  • US 5,491,471 A
  • Filed: 10/22/1992
  • Issued: 02/13/1996
  • Est. Priority Date: 10/23/1991
  • Status: Expired due to Term
First Claim
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1. An access control system for controlling access of individuals to an area comprising:

  • at least one programmed data carrier, each programmed data carrier being assigned to an individual and having a programmable memory includingi. bits in a predetermined format defining authorization data, said predetermined format and said authorization data being specific to the individual and the area; and

    ii. control data identifying saidpredetermined format;

    a stationary reading device installed adjacent to the area for receiving control data and authorization data from said data carrier, said stationary reading device having uninitialized and unprogrammed programmable reader memory, said reader memory being programmable to identify one of a variety of different formats;

    locking means installed adjacent to the area for controlling acess to the area; and

    central evaluating means including check data, said central evaluating means coupled to said stationary reading device and said locking means;

    said reading device reading said data carrier with said control data programming said reader memory to read and transmit only the bits in the predetermined format, so that said reading device relays said authorization data unaltered to said central evaluating means,whereby if said authorization data matches said check data, said central evaluation means instructs said locking means to allow access to the area.

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