JPH01500340A - personal memory card - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] personal memory card Background of the invention 1. Technical field The present invention uses smart cards, more specifically contactless interfaces. Relates to smart cards that communicate or interact with processing systems via.

2. Description of prior art Using credit cards for shopping, banking and other transactions Today's travelers usually don't carry much cash. A plastic card with an embossed account number and account name is simply a bank card. Rui is the authorized account that should be the billing light for Transaxilan at the credit company. The magnetic strip on the back of some cards whose only function is to identify the card is similar to this. Contains the same information, but can be read out mechanically to speed up transax is now possible. All account information is stored at your bank or credit card company. will be paid.

Transaxilan is usually carried out away from the bank or credit company. fraudulent cards are used, or even legitimate owners inadvertently There may be cases where the limit amount is exceeded. Most sellers therefore offer relatively high prices, For example, if you are making a purchase over 850.00, please check with your bank or credit company. It is necessary to carry out verification. Even with automatic dialing, this process is time-consuming. It's work. Additionally, separate cards are required for each account.

However, with recent advances in microelectronics, today a large number of By incorporating summer power and memory directly into the card, you can create a “smart card”. t card)’” or 1 personal memory card (personal It is now possible to create a ``memory card''. Personal identification data, e.g. personal characteristics, The card may also contain information such as a driver's license, social security number, personal identification number, or voice print. The owner's credit is the account number of all sales accounts, the balance of all accounts, and the balance of all accounts. Credit limit and other personal data, for example when buying clothes It can also include family size, phone numbers, etc. These personal data This could be any type of data imaginable.

Technology already exists to store all this on a standard size card. This convenient card The problem holding back the card's growth is the lack of adequate input to power the card. the absence of an interface and the connection of data to or from the card. It is a question of trustworthiness.

Smart cards known in the art can be carded by various contact methods. Reading from or writing to the card is performed. If metal contacts are used One problem when using The goal is to increase Omink contact. This is a card and read The speed of data transmission to and from the write device is Gives problems for tact to increase and decrease.

In addition to this, the contacts, in exposed locations, do not float in the air on the surface. allowing particles to settle out, thus reducing the contact area and resulting in rupture. connection. The operating power for reading or writing from the card is also are supplied to the card via these contacts from the associated station run in the system. over time, the amount of energy provided decreases and the card is unable to operate. It becomes impossible.

Uses metal contacts to provide power and data to smart cards The second problem is electrostatic discharge. rge%ESD) occurs, which causes the microelectronic There is a risk that the ronix may be damaged. If metal contacts are used If the card is inadvertently stored on the body or on the card, or from other sources. High voltages coupled to the card can easily be coupled directly to the electronics on the card. It will be done. There are no clamping diodes used at various inputs on the card. Provides some level of protection, but when the card is used normally within a normal environment. , are vulnerable to the high voltage levels that sometimes occur.

Summary of the invention According to the invention, the card is typically identical to a standard plastic credit card. sized personal memory card from the customer repertoire diary for various purposes ranging from keeping medical and/or banking records. used on the way. This card looks like a traditional credit card However, in computers, electrically erasable field read-only memory (EE FROM), and for receiving a combination of power and timing signals. data signals between the board and the read/write device located in the associated station run. between the card and the read/write device, including circuitry for receiving and transmitting the To provide power to the card or send data to or from the card No direct ohmink electrical contact is made to receive, therefore the car The reliability of the power supply to the card and the transmission of data to and from the card are is well warranted even after the card has been used extensively. In addition to this, Possible electrostatic discharge damage to Lectronics occurs when the conductors on the card and the discharge Minimum insulation between possible sources is provided in the form of a dielectric. Being held down. This personal memory card can also be used by authorized users. Selectively reproduce with new and different data if necessary at the relevant station run. It is possible to gram.

The invention and its mode of operation may be further understood by reading the following detailed description together with the accompanying drawings. This becomes even clearer.

Brief description of the drawing FIG. 1 shows a personal memory card and reader operable in accordance with the principles of the present invention. FIG. 2 is a functional block diagram of an output/write device; FIG. Figure 3 shows the basic structure of the Null Memory Card and the arrangement of the main elements on it; Main functions of the analog interface circuit shown in the memory card in Figure 1 is a schematic diagram showing the elements in more detail; and FIG. 4 is a schematic diagram showing in more detail the main functional elements of the read/write device of FIG. Ru.

Like elements are designated with like numbers throughout the drawings.

■Saiou Asuri FIG. 1 shows a card reading/writing device 15 according to the principles of the present invention. A block diagram of a portable data or personal memory card 10 is shown below. shown. The main elements contained within the card 10 include a microcomputer 110; , electrically erasable programmable memory sable programnable read-only memory E EPROM) 1 1 5, analog interface circuit 300, ) secondary winding vA121 of transformer 120, and capacitive plate 125 to 1 28 are included.

The microcomputer 110 has a central processing unit and random access memory. and its internal read-only memory, including memory units in the form of read-only memory. The microcomputer operates under firmware control provided by Data sent directly to EEPROMI 15, and analog input Format the data sent to the read/write device via the interface circuit 300. - turns into a cloak. The microcomputer 110 also has an analog interface 300 to interpret instructions received from the read/write device. In addition to this The microcomputer 110 reads data from the EEPROMI 15. or writing to this and reading/writing device 15 or from now on. Checks for errors that occur during data transmission.

By using the EEPROMI 15 in the card 10, authorized users can The associated application cage 5 allowed some cefsilane on the card if necessary It can be reprogrammed with new and different data at the station station. . EEFROM is supplied by multiple vendors, but many of these vendors Elektro by Robert Lineback (J, Robert Lineback) Toni') Z (Electronics, Vol, 59, hl (1 Paper published on pages 40-41 (February 17, 1986 issue) [Has it entered the final stage? E F ROM (Are EEPROMS Finally) Ready To Take Off? ), described on pages 40-41 It is. Data must be written to the EEPROM while operating power is applied. It is possible to erase or unread the data. operating power is removed Then, all modifications made to the data in EEFROM remain intact and the card A search is possible each time the code 10 is repowered.

The analog interface circuit 300 reads/writes the memory card 10. Provides a means for interfacing to the device 15. This interface reads Card 1 with operating power from magnetic energy coupled from write/write device 15 0 and the read/write device 15 and the microcomputer in the card 10. performs a number of functions including combining data between data processors 110; Power to card 10 - from the read/write device 15 to the secondary S&! of the transformer 120. to 121 Analog interface circuit through inductive interface provided by 300.

This transformer is connected to the read/write device 15 by this secondary winding in the card 10. Primary tk&l in! 122 (mating).

The transformer 120 has a primary reference line 122 of the transformer and a secondary t! vA1 Ferrite core 1 in read/write device to increase coupling between 21 23, and a number within the transformer 120 to further improve coupling efficiency. The secondary t&! in the card, including the ferrite core 124 of 2! associate with 121 You can also do that. In cases where there is plenty of power and efficiency is not an issue, One or both of these cores can be omitted. Power to credit cards The use of transformers for the purpose of combining Applied by R,L, BilBllin on the 5th. No. 664,555, “Flexible Inductor (Fl ExibleInductor)”.

The reception or future transmission of data to the card 10 is via an analog interface. The electrodes or plates 125 to 128 on the memory card 10 are Corresponding electrodes or plates 115 to 158 in the output/write device 15 include A capacitive interface consisting of four capacitors is formed when provided. Two of these capacitors are connected to the card from read/write device 15. used to transmit data to card 10, and the remaining two to read from card 10. /Used to transmit data to the writing device 15. inductive interface and capacitive interface combination read/write device N15 and memory card 1 provides a complete communication interface between Figure 3 shows the analog interface. The base circuit 300 is shown in more detail and will be discussed in more detail later. It will be revealed.

The organization of several elements within the read/write device 15 is card l.

It has a functional mirror relationship with the elements within. These elements include, for example, There is an interface circuit 400 and a micro combinator 410. In addition to this, Read/write device 15 includes power source 162 and input/output interface 160 A power source 162 includes a power source 162 for providing power to the card 10 and for reading/writing. The clock signal from the embedding device 15 is transferred to the card 10 through the transformer 120. used to join. In principle, the input/output interface 160 is universal asynchronous receiver transmitter eiver trans + 5 itter% UA RT), and micro Included within computer 410. This υART is Used for external communication with the station run.

Figure 2 shows the basic structure of the card 10 and the positional relationships of the main elements on the card. . Cards come in o, oo inch thick single or double sided print layout. Capacitive plates 125 to 128 having a thin plate structure including a line substrate 201 are connected to this plate. Although shown spread out on the top side of the lint wiring board, these As long as it is covered with an insulator or dielectric sheet, the bottom of the board, i.e. A contralateral position is also possible. Analog interface circuit 300, my Chrome computer 110, EEPROM 115, transformer secondary-tI line 121 and pads for adhering surface mount capacitors 302 and 315 to the base F. It is located on the upper side of i201. Integrated circuit, i.e. microcomputer 11 0, EEPROMI 15 and analog interface circuit 300 are printed The wire is bonded to the wiring board 201, and the capacitor is conductively coated with epoxy. Joined. Other methods of electrically connecting integrated circuits to printed wiring board 201 are also possible. Well known in the art. - Using tape automatic bonding method as an example You can also do that.

Starting with the explanation of the structure of the card 10, approximately 0.020 inch is placed on the printed wiring board 201. Ti1tfi of the inch-thick structural member 202 is located. This structural member is printed A plurality of openings accommodating the physical sizes of the above elements to be mounted on the wiring board 201. with an opening 203, then covering the element positioned within this opening and also the structure These elements have a concave upper surface that aligns with the topmost portion of the material 202. A sufficient amount of potting material is applied to It will be done.

A thin top cover sheet 204 is layered onto the structural member 202. This cover Appropriate labels and logos are affixed or stamped onto the sheet. double side A thin dielectric sheet is attached to the back side of the printed wiring board 201, which allows this Conductor leads (and conductor plates) located on the underside of the board and otherwise exposed will be covered. instructions and, if necessary, a magnetic stripe and signature panel. It is usually at this location on the inside bottom of the card.

FIG. 3 shows the analog interface circuit 300 of FIG. 1 in more detail. . Many functions for the memory card 10 are provided by this interface circuit. For example, this interface circuit can be used for power rectification and regulation, readout, etc. /Transmission of data to the writing device 15 or future reception, Microcombie Transformer secondary volume for operation of data 110! Clock signal from 121 , power was once disconnected from memory card 10 and then reapplied. Functions such as power and reset operation to reset the microcombiner I will provide a.

Secondary −12m12 from read/write device 15 through transformer 120 1 is an approximately 1.8 MHz AC signal. This secondary The output of winding 121 is applied to a full wave bridge rectifier 301. bridge rectifier 3 The DC pressure generated by 01 is filtered by capacitor 302 and then It has a shunt regulator cefsilane at the end and a series pass regulator at the rear end. A two-part regulator 303 is coupled thereto.

This shunt regulator is the current drawn from the transformer secondary t'161121. current is held constant, thereby maintaining the maximum on the power transfer curve of the transformer 120. Ensures operation within proper range. This reduces the power demand within card 10. Then, the shunt regulator Cefsilane connects the read/write circuit 15 and the AC power. In order to maintain a constant load on the transformer secondary winding 121 receiving the Necessary to dissipate excess power. On the other hand, a large amount of power is required within the card. When the desired operation begins and the power demand increases, the shunt regulator cefsilane detects a decrease in voltage and reduces its power dissipation. The current is then connected to the series pass voltage. Flows to the pressure regulator and provides power to all other circuits in the card.

Capacitor 315 is an additional shunt/series path to the DC output of regulator 303. Providing a wave of support.

Clock recovery circuit 304 is suitable for operation of microcomputer 110. The secondary tI! of transformer 120 to provide a lock signal! join to 121 be done. This circuit 304 is connected to one side of the secondary JI1121 of the transformer 120. It consists of a comparator that compares the difference between the bridge rectifier 301 and the ground node. offer The generated pulse is shaped by a comparator and is used to drive the microcomputer 110. Provides fast turn-on and turn-off times suitable for

A circuit consisting of a voltage reference 306, a comparator 307 and a monostable multi-bi break 308. The set circuit 305 outputs the regulated output of the shunt/series path regulator 303. Monitor. This circuit is a shunt/series path for supplying power at the output of regulator 303. When the pressure is not within a predetermined operating range, the operation of the microcomputer 110 is inhibited. do.

A resistor string consisting of resistors 309 and 310 is connected to a resistor string from regulator 303. The voltage coupled to comparator 307 is decreased. and the voltage reference 306 is required Set a threshold voltage level that corresponds to the lowest acceptable operating level. This level Bell is then compared to the voltage from the resistor string in comparator 307. in action Then, when the voltage across the shunt/series path regulator 303 rises from 0, The voltage supplied to the comparator from the voltage reference 306 is supplied to the comparator from the resistor string. The voltage will be higher than the supplied voltage, and the microcomputer will remain reset. The voltage from the 0 shunt/series pass regulator 303 rises above the minimum operating voltage. , the output of the resistor string is higher than the voltage reference (then the comparator 307 becomes Changing the state, the monostable multivibrator 30B produces pulses approximately 200 milliseconds long. is provided to the microcomputer 110. This allows the microcomputer 110 is activated and the processors included therein begin execution.

At some point after reaching the desired operating level, the regulated voltage will If the voltage drops below the threshold voltage level, the reset circuit 305 detects this drop. and inhibits the microcomputer 110. This is in EEFROMI 15 ensure that no extraneous operations occur that would adversely affect the data. One Therefore, the reset circuit 305 turns off the microcomputer when the voltage falls below a predetermined operating voltage. inhibits the computer 110 and thus prevents the card 10 from malfunctioning in such low voltage conditions. protection from cropping.

Such unreasonable voltage may occur if the card 1o is not fully inserted into the read/write device 15. If not, between the front surface of the card 1o and the receiving surface in the read/write device 15 This occurs when the gap becomes too narrow due to the accumulation of obstructions on either surface. do. The reset circuit 305 is also activated by an interruption in the voltage to the card. Therefore, if AC power to the read/write device 15 is interrupted or the user , if the card 10 is removed from the read/write device 15 at an inappropriate time. , the microcomputer 110 is inhibited. microcomputer 110 Operation resumes once the supply voltage is at normal operating levels.

Data out drive circuit 311 consisting of driver amplifiers 312 and 313 receives serial data from the microcomputer 110 and reads/writes them respectively. Capacity for interfacing with capacitive plates 155 and 156 in writing device 15 differentially driving the sexual plates 125 and 126. These drivers 312 and 3 13 is a microphone for serial data from the microcomputer 110 having one polarity. Each transition of the signal from the computer 110 causes one of the drivers to be positive and the other to be positive. Convert to a differential polarity such that is negative.

The data receiving circuit 320 consists of a differential amplifier and is a capacitor in the read/write device 15. coupled from the static plates 157 and 158 to the capacitive plates 127 and 128. Used to receive difference data. Data from this read/write device 15 The data processor is connected to a microcomputer 110 in the card 10 to perform appropriate processing. will be combined. The data receiving circuit 320 has hysteresis greater than this hysteresis. The differential pulse changes the output of the amplifier from a high state to a low state or from a low state to a high state. Constructed to be all that is needed to switch to a value state. this hiss Telisys ignores small differential noise signals and switches only large differential data signals This prevents the data receiving circuit from being accidentally triggered by noise. i.e. once the state of the data receiving circuit is switched , unless there is further input, this will cause it to remain in the switched state and switch to another There is no drift in the state.

Contactless cards minimize electrostatic discharge (ESD) issues. However, the output of the data drive circuit 311 and the input of the data reception circuit 320 Design additional protection diodes to clamp the voltage and include them within the card circuit. can be done.

Clamp circuits for clamping these voltages and integrating them to safe levels are available to those skilled in the art. It is well known in

FIG. 4 schematically shows the main functional elements of the read/write device 15 of FIG. A memory card 1 shown diagrammatically in FIG. 1 and graphically shown in FIG. 0 is shown in FIG. 4 as the data and power coupling elements of the read/write device 15. You will be shown whether to contact. Power to the card comes from read/write device 15 The secondary winding 121 in the card 10 is connected to the primary winding [122] in the read/write device and The primary transformer 120 formed when Provided via @9122.

As mentioned above, data transmission between the read/write device 15 and the card 10 is The plates 125 to 128 on the card correspond to the corresponding plates in the read/write device 15. The capacitive interface formed when metering from rate 155 to 158 provided by the source. The read/write device 15 generates data in the memory card 10. Similar to a card IO containing multiple elements with the same behavior as the element being viewed, the readout The write/write device 15 includes a non-inverting driver amplifier 401 and an inverting driver amplifier 402. Contains a data out device circuit consisting of. These amplifiers are UART40 3 receives serial data from the capacitive plates 127 and 1 in the card 10. Differentially driving capacitive plates 157 and 158 that interface with 2B . Data for the memory card 10 is transferred from the microcomputer 410 to 8- It is sent in parallel to the UART via the bit bus 411.

The read/write device 15 also includes a data receiving circuit 404, which is a differential amplifier. The capacitive plate 1 in the card 10 is read/written by a read/write device 15. 25 and 126 coupled to capacitive plates 155 and 156; used to. This serial data from card 10 is UART40 3, where this is re-fortified into parallel data and then 8 - coupled to the microcomputer 410 through the bit data bus 411; Ru. Microcomputer 410 uses internal DART to open this data. reconvert to serial format with start and stop bits, then convert this data The card 10 and the print/write device 15 are configured to communicate with a particular application. application station 440.

Applications Stacylans can have a variety of configurations. In other words , Factory Edit Stacy Run, Office Edit Stacy Run, Publisher Edit Stacy Run , a public telephone, or any other device suitably configured to interact with the card 10. It can be configured as another stationary run.

A circuit for efficiently controlling the power supply to the card IG is used for read/write circuits. It is included within path 15. Power driver 420 is the primary of transformer 120 Controls the level of power transmitted to the volume &l91122. tran on card 10 The power provided through the secondary winding 121 of the transformer is is proportional to the t flow in the primary order 41122 of the matrix. by driver 420 at any time. The amount of power supplied to card 10 is supported within transformer primary 41122. and this information is provided to analog-to-digital converter 421. this The converter receives analog power sampled by the microcomputer 410. Provides a digital signal equal to the level. On the other hand, the microcomputer 410 , a signal provided to a digital-to-analog converter 422 to provide power to the card 10. Adjust to the desired drive level.

The output of this digital to analog converter is coupled to voltage regulator 423.

Regulator 423 provides constantly corrected drive power to card lO. power to the power driver 420. In this way, the power to the card lO is positive. controlled within the desired range for constant and efficient operation.

In order to use the card with the read/write device 15, the card must be read/written. It is required to insert it into a receiving slot within the device 15. Card 10 and reading /Ensuring that the interface elements within the writing device 15 are properly mated. to verify and to ensure correct turn-on of the read/write circuit. , a proximity sensor is located in a slot in the read/write device 15 . card The in sensor 425 is located about half way towards the inside of the card slot. . This is a light sensor with illumination and detection elements. ll machine arm is card slot The light beam produced by the lighting element when it reaches about halfway inside the is arranged such that it is blocked and detected by the sensing element. This card inset The sensor 425 is used when a card is inserted into or removed from the stationary run. When it reaches the location, it sends a signal to the microcomputer 410.

Card full-in sensor 426 also operates similar to a card-in sensor. is located at the innermost position of the card slot. This sensor is a card When it is completely inserted into the slot, the micro combinator 41G is notified.

The read/write device 15 has reprogrammable microelectronics. Not only personal memory cards, but also magnetic stripes attached. It is also designed to accommodate multiple cards. When the card is fully inserted, the card is a contactless memory card or only has a magnetic stripe. A test is performed to determine which cards are the same. This test is micro By the computer 410 supplying power to the power driver 420 will be started. If power is drawn from the transformer primary winding 122, then The read/write device 15 assumes that there is a memory card in the slot. If the read/write device does not have a magnetic stripe card in the slot. considered to exist.

When the card is fully inserted, the transformer's primary t'&? 1122 Once it is determined that it is a memory card based on the current drawn, the read/write to bring the communication interface in the device 15 into contact with the inserted card; Solenoid 427 is activated by microcomputer 410. This inn Capacitive plates 155 to 158 and transformers constituting the interface The next winding 122 is placed on the platen for best capacitive and inductive coupling with the card. The solenoid is installed so that it gives deflection to the card. It will be posted. If the card is partially pulled out, the card becomes full-in sensor. When 426 is tripped, solenoid 427 is activated for easy card removal. will be released immediately.

If the test to see if it is a memory card shows that it is not a memory card, the Microcomputer 410 is a card with only a magnetic stripe inserted. decide something. Then, the microcomputer 410 takes out the card. send an audible or visual signal to the user to the card is pulled from the slot When output, the data on the magnetic stripe is read by the magnetic head 430. is amplified by the amplifier 431, and then the serial data on the microcomputer 410 is Combined with al boat.

An oscillator section 435 is included within read/write device 15 . this sexy The version is a clock signal and power driver for the microcomputer 410. It provides a signal of approximately 1.8 MHz for 420. Black 7 recovery in Figure 3 Circuit 304 is suitable for operating microcomputer 110 in FIG. It is this signal that is detected to provide the lock signal.

A clock signal for the data transmission circuit is also provided by oscillator section 435 Provided to ART403. This signal is transmitted between the card 10 and the read/write device 15. Set the data transmission rate to 19.2 kph/sec. This data rate ensures that the capacitive plates are correctly biased throughout the period between data bit transitions. This provides a communication interface between the card and the read/write device. The negative effects of noise caused by voltage drifts experienced by the ground are minimized. .

The microcomputer 410 has an external random access memory IJ (RAM) section 437 and external read-only memory (110!1) section 436 With additional memory in the formula, R The OM section can be easily replaced with or augmented by the EEPRO section. I can do it in minutes. This in read/write device 15 and/or station 440 The EEPROM is read/write device 15 so that the card can operate. Easily reprogrammed by the data contained within the card when contacted can be used.

As mentioned above, the microcomputer 410 connects the outside world and the system to the station 440. Communicate via real data path. This data path includes the transmitting lead 441 and the receiving lead 441. includes a communication lead 442, which is also read by the card full-in sensor 426. This includes an attention lead 443 that is activated, which is also a reset lead. 444, using which station 440 reads/writes device 15 and initialize it to a known state.

Power to read/write device 15 is also provided by station 440.

Without departing from the spirit and scope of the invention, one skilled in the art will appreciate that this memory It is obvious that many other variants of the card can be realized. As an example of these transformations, The data running within the system is sent only from the memory card to the card reader. It is also possible to realize the Memory card and/or associated card card reader to establish and maintain data flow from card to card reader. with the required minimum communication interfaces and microelectronics It is configured as follows. Accordingly, within the scope of the appended claims, the invention resides in the invention as specifically described above. Implementation as described in! You can understand that it is possible to implement it other than IE.

FI6.2 international search report m”mk POT/lJs 87100784 2λ Mushizumi xTo Tag!N TΣRNATZONAL SEMLCHREPORT 9NIN? TRNATI ONAL APPr, ICATION No, Pσr/lJs 871007 84 (SA 17010) n-A-2548803LX101/85 Non eF’R-A-254279221109/84 None

Claims (11)

[Claims] 1. Memory means (115) for storing data and for processing data. In a portable data card (10) comprising processor means (110), The data card communicates with at least one read/write station (15). input/output means (125-128, 300) for read/write data from the station to the data card and from the data card. Capacitive coupling means (125-128) for transmitting to read/write stations including; the data card further includes: receiving magnetic energy transmitted from the read/write station; electrical energy for energizing the memory means and the processor means; energy coupling means (120) for converting into Cooperating to create one complete connection between the data card and the read/write station including capacitive coupling means and energy coupling means for providing a communication interface; A portable data card that features: 2. The portable data card according to claim 1, wherein the capacitive coupling a serial connection between the portable data card and the read/write station. the series connection connects the electrodes in the card to the read/write station. A portable device characterized in that it is established by close alignment with an electrode of data card. 3. In the portable data card according to claim 2, the matched individual A dielectric material is deposited on at least one of each of the two electrodes, and the dielectric material A portable data card characterized by being placed in parallel between the poles. 4. The portable data card according to claim 1, wherein the memory means the data card is in operative contact with the read/write station. Consists of electrically changeable programmable read-only memory that can be modified when A portable data card characterized by: 5. The portable data card according to claim 1, wherein the energy The coupling means comprises a flat multi-turn coil of electrically conductive material and a rectifier connected to the coil. A portable data card comprising: a portable data card; 6. In the portable data card according to claim 1, the input/output an analog stage for coupling data between the capacitive coupling means and the processor means; an interface, wherein the interface circuit receives a serial signal from the processor means; for receiving data and differentially coupling this serial data to a nuclear capacitive coupling means; A portable data card comprising first and second amplifiers. 7. The portable data card according to claim 6, wherein the capacitive coupling a stage includes first and second electrodes on the portable data card; amplifiers respectively read/write serial data from the processor means. connected to the first and second electrodes for transmitting to a station. portable data card. 8. The portable data card according to claim 7, wherein the analog input An interface circuit further receives difference data from the capacitive coupling means; a third quadrupler for coupling the processor means to the processor means; Tuple data card. 9. The portable data card according to claim 8, wherein the capacitive coupling a stage further includes third and fourth electrodes on the portable data card; An amplifier transmits difference data from the read/write station to the processor means. a porter coupled to both the third and fourth electrodes for transporting the third and fourth electrodes; bull data card. 10. The portable data card according to claim 9, wherein the analog An interface circuit further connects the supply magnetic energy to the energy coupling means. timing means for deriving a timing pulse proportional to the frequency of and between the memory means and the processor means by the timing pulse. timing of data transmission between the data card and the read/write station; A portable data card that is characterized by the fact that 11. The portable data card according to claim 10, wherein the process A portable data card characterized in that the processor means comprises a microcomputer. code.