초록 ▼

A credit card system includes a credit card containing a memory for storing coded information indicative of: an identification of the use for which the article is intended, an identification of units used to keep account of operations which are performed in connection with the credit card, and the n

A credit card system includes a credit card containing a memory for storing coded information indicative of: an identification of the use for which the article is intended, an identification of units used to keep account of operations which are performed in connection with the credit card, and the number of units available to a holder of the credit card. The memory is structured so that the two identification data zones have bits wherein a change from one binary value to another is irreversible, to prevent tampering of the identification of the card. The card also includes circuits for controlling the memory and contacts for temporarily coupling the card to an imprinting and/or operating means that are respectively coupled to the card at the time it is purchased and when it is being used to purchase goods or services. When the card is purchased, the number of units is imprinted onto the card in the third zone, and the number of these units is decremented as the card is being used.

대표청구항 ▼

A system for keeping a record of predetermined homogeneous units comprising: an article bearing information, external means for imprinting and/or operating on the information on the article, said article comprising: a memory for storing coded bits in first, second and third fields, said first field

A system for keeping a record of predetermined homogeneous units comprising: an article bearing information, external means for imprinting and/or operating on the information on the article, said article comprising: a memory for storing coded bits in first, second and third fields, said first field having an unalterable multibit field indicative of an identification of the use for which the article is intended, said second field being an unalterable multibit field having an identification of the units used to keep account of operations which can be performed with the article and the third field being an alterable multibit field indicative of the number of credit units available to the holder of the article; circuits for controlling the memory; and means for temporarily coupling the article to said imprinting and/or operating means; said external imprinting and/or operating means including means for reading data from and writing data into the memory of the article; said external means including: means for writing into the memory of the article indications of at least one of the following parameters: (a) the number of units required or received by the holder of the said article within the limits of the capacity of the memory, and (b) the number of units received or required by the holder of the article to be subtracted from the number of units available in the memory of the article. In combination, a credit card having a first binary memory field having N1 bits, a second binary memory field having N2 bits, where N1 and N2 are predetermined integers greater than one, bits of said first field being subject to change in response to signals from an external device, bits of said second field not being subject to change in response to signals from an external device after having been stored in the second field, a pre-selected number of bits stored in the second field having a first binary value, the bits of the first value in the second field, once stored, being irreversible, an external device including first and second means, said first means reading bit values from and supplying bit values to the first field so that bits stored in the first field are altered in response to signals from the first means, said second means including means for reading bit values from the second field, and means for deriving an alarm signal in response to the bit values read from the second field by the second means indicating that the number of bits in the second field differs from the pre-selected number for the first value.