The present invention relates to a system for carrying out a chosen activity with a first unit with a memory for storing of specific data, preferably personal data, in occurring cases comprising a keyboard and a display, comprising a card for activating of the first unit, by correspondence between the card and the first unit, by adding from the card to the first unit a first code, which card comprises at least one programmable memory, for carrying out a chosen activity. Such systems are common and may be used for withdrawal of cash whereas the first unit usually is called e g Bankomat (from the beginning a trade Mark, which has developed to a common name for systems of this type) . The system may also relate to the activity to pay a parking fee at a parking lot with a parking automat, or the activity to unlock a lock unit with a card. Other systems with units cooperating with cards are also conceivable. A problem with these system is the lacking security. Thus it has been obvious, that is relatively simple for unauthorized with knowledge of card systems to achieve the code, that is normally utilized in these connections. Generally a first unit, e g a withdrawal unit, and a card are programmed with data for one user and a four number code, chosen by the user. In addition thereto there is, as far as a withdrawal unit is concerned, the balance of the user programmed in the memory of the withdrawal unit, in which case the user inserts the card into the withdrawal unit and supplies the four number code to the keyboard of the withdrawal unit, and gets a confirmation at the display of the withdrawal unit, that the correct code has been supplied. Then the user supplies a desired sum to the keyboard, which is paid by the withdrawal unit in the form of bank notes, if the balance shows at least a corresponding sum. The user may then, by corresponding pushing of buttons get a print of the actual balance and a list of the latest depositions and withdrawals of the account in question. Such systems are simple in use but it is relatively

simple to withdraw cash unauthorisedly from an account, that is by a person who has got access to the card and has also got access to the four number code, e g by observing when the righteous owner of the account supplies this code to the keyboard of the withdrawal unit As to other chosen activities, such as paying of parking fees and unlocking locks there is a demand for security against unauthorised use of cards.

There is thus a great demand for a system of the art mentioned introductorily, which is easy in use and safe against unauthorised withdrawal of cash.

According to the invention such a system of the art mentioned introductorily is characterised primarily in that the card is provided to permanently store in the memory a first portion of said first code and is provided to be able, before the occasion of activation of the first unit, to be completed with a second portion to a complete first code, whereas the first unit or the card is arranged to erase said second portion of the first code from the memory of the card, after the performance of a chosen activity with the first unit.

If the chosen activity means withdrawal of cash from a withdrawal unit this comprises a keyboard and a display and has a memory for storing information about the balance for means, able to be withdrawn in the form of cash by supplying the first code. At this embodiment the sum to be withdrawn is supplied to the keyboard of the withdrawal unit and the chosen sum is paid, normally since the key "Clear" has been activated. In one embodiment of the invention the card is provided to be able furthermore, to be programmed with a sum for withdrawal. In this case the chosen sum is paid as soon as the card has been brought in contact with the withdrawal unit, possibly after activating the key "Clear".

In one embodiment of the invention relating to withdrawal of cash from a withdrawal unit, which means further security against abuse, the card is provided to be able to be programmed with a second code, whereas the withdrawal automat is provided, to store this second code

together with the first code and at occurring cases the programmed sum, at correspondence between card and withdrawal automat, whereas the withdrawal automat is provided to pay said sum by- adding the second code to the keyboard. It is suitable, that the withdrawal unit is arranged to erase this second code after payment of said sum. In one embodiment of a withdrawal automat this is arranged to transfer information about the balance to the card after payment of cash. The user may thus, if desired, refrain from requiring a printed balance information from the withdrawal automat.

As already mentioned the chosen activity may mean paying of parking fee, whereas the first unit comprises a parking automat with a card reader and display. In this case, the complete first code is transferred to the parking automat and by pushing a button the desired parking time is chosen, whereupon a corresponding amount is debited the account of the user.

If the chosen activity means unlocking of a lock, the first unit is a lock unit, which is arranged to be opened by supplying from the card of the first code by drawing the card through a card reader. Within the scope of the invention, there is the possibility of a wide number of embodiments. Per se, suitably the second portion of the first code consists of four numbers, but it may also consist of another number of signs of different arts, like letters and other symbols. The same is also true for the second code.

The card may be programmed by a separate module, comprising a display and a keyboard. The programming may then be performed correspondingly, depending on the design of the card and the art of its memory, i e by direct electrical contact between module and card, or by wireless communication between module and card.

In one further embodiment the card comprises a display and a keyboard for direct programming.

The invention also relates to a card to be used in a system according to the enclosed patent claims and methods for the systems.

The system according to the invention shall now be disclosed more in detail, reference being made to the activity withdrawal of cash from a first unit in the form of a withdrawal automat reference being made to two enclosed, schematic figures, of which figure 1 shows, in perspective, a module with a card mounted for programming,. Whilst figure 2 shows a view to a card according to an alternative embodiment.

In this embodiment the system thus comprises one not shown withdrawal unit, for instance of the art called Bankomat with a memory, which may store information for the identification of a person ^' s account and balance. It has a card reader with an opening in the form of a narrow slot where a card may be inserted, and has also a keyboard and a display. In figure 1 there is shown a module, generally denoted 1, a plane support 2 for releasable mounting of a card 3. The support also is in flexible connection with an electronic portion 4 with an indicated keyboard 5. This may consist of several portions, that is to say partly for supplying code and partly for choice of function, related to codes or sum etc. The support is in flexible connection with a display part 6. In the module the electronic portion 4 may correspond with the card 3 either by direct electric connection of the art provided at cards for telephone service in telephone automats, or by wireless communication between electronic portion and card.

The card 3 has at least one programmable memory, which permanently contains the first portion of a first code. On occasion of withdrawal the first code is completed with a second portion, for instance consisting of four numbers by corresponding supply to the keyboard of the module. This second portion of the first code will be erased when cash has been withdrawn, preferably by the withdrawal unit, but this erasure may also be performed by corresponding programming of the card. In this embodiment of the invention the card is provided to be programmed with a second code, freely chosen in connection with the occasion of withdrawal. It may e g consist of four numbers. Also the

planned sum for withdrawal may be programmed in the card. When the owner of the card wishes to withdraw cash, the card is brought into corresponding contact with the withdrawal unit, and the owner of the card supplies the freely chosen second code in order to activate the "compartment" in the memory of the withdrawal unit, where information about the owner of the account and possibly the planned sum for withdrawal are stored. Alternatively this sum may be decided by supplying the keyboard of the withdrawal not earlier than when the "compartment" is activated. As mentioned the second portion of the first code will be erased when cash has been withdrawn. The same is true for the freely chosen second code. In figure 2 there is shown a card 7 for direct programming of the second potion of the first code resp de second code and the desired sum for withdrawal from the actual account. This card has a display portion 8, a first keyboard 9 and a second keyboard 10. In the first keyboard the second portion of the first code chosen in advance, is supplied, and also the second code. The second keyboard is used for choice of function, that is to say the second portion of the first code resp the second code and if relevant, the planned sum for withdrawal. The buttons here are suitably of the capacitive type, that is to say it is enough to touch the buttons to activate resp number or letter. In the module and card simple batteries are used for driving memory circuits etc. The second keyboard may contain several keys for different choices of function, e g for erasure for false activation, sign for clear, possible programming of time delay before next cash withdrawl is possible etc.