JPH0193399A - Ic card - Google Patents

Abstract

PURPOSE: To prevent electrostatic breakdown of a built-in IC module and contact failure caused by the contamination of a contact terminal by burying the IC module and flat electrodes connected with the IC module in a plastic card, and connecting each flat electrode and a reader/writer by the capacitive coupling by AC. CONSTITUTION: In an IC card, an IC module 1 and the flat electrode 2 are buried in a plastic card 3, the IC module 1 and each flat electrode 2 are electrically connected, and each flat electrode 2 is covered by a dielectric so that it is not exposed. On the other hand, a reader/writer comprises the flat electrodes 19 opposite to the flat electrodes 2 buried in the IC card, the flat electrodes 19 of the reader/writer and the flat electrodes 2 of the IC card are alternatingly connected through the electrostatic capacity formed therebetween when they are close to each other, for performing the exchange and processing of the data to the IC card.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an IC card having no mechanical contacts.
The IC card is configured such that power is supplied to the IC module in the IC card and signals are sent and received through capacitance without using mechanical contacts.

(Prior Art) A conventional IC card, as shown in FIG. 3, has a microprocessor and memory inside a rectangular plastic card 3.
An IC module made of a chip is provided, and the IC module is electrically connected to a plurality of external contact terminals 25 provided on the surface of the plastic fist card.

As shown in the block diagram of FIG. 4, a conventional IC card includes a CPU 21, a RAM 22, an EEPROM 23, and a
1024, and the external contact terminals 25 and 1024 are electrically connected by lead wires.

The functions that each external contact terminal 25 has are Vcc...
Power supply input terminal Rst...Reset signal input terminal I10...Data signal serial input/output terminal CLK.
...External clock input terminal VPP...Write power supply input terminal Gn to EEPROM
d: O port level input/output terminal for power supply and data signals, etc.

(Problems to be Solved by the Invention) As described above, in conventional IC cards, since the external contact terminals 25 are exposed, there is concern about electrostatic damage to the built-in IC module, and contamination of the contact terminals. This may result in poor contact.

(Means for Solving the Problems) Therefore, the present invention was devised to solve the problems of IC cards based on the exposed external contact terminals, and is based on the fact that the external contact terminals are exposed. Each plate-shaped electrode connected to this IC module was embedded in a plastic card, and each plate-shaped electrode in this IC card was connected to a reader/writer by capacitive coupling using alternating current. It is something.

In order to improve portability, IC cards have a larger surface area than the built-in IC module, so it is easy to provide electrodes for obtaining coupling capacitance.

(Example) As shown in FIG. 1, an IC card according to the present invention has an IC module l and a plate-shaped electrode 2 embedded in a plastic card 3, and the IC module 1 and each plate-shaped electrode 2 are electrically connected. These plate-shaped electrodes 2 are covered with a dielectric material so as not to be exposed.

Among these plate-like electrodes 2, the areas of the power input electrode Tvcc, the 0 port level input/output electrode Tgnd, and the EEPROM write power input electrode Tvpp, which transmit particularly large amounts of power, are increased to increase the coupling capacitance. However, other signal electrodes Trst and Ti10 transmit less power.
Reduce the area of

A rectifier circuit 4 for rectifying alternating current into direct current and a smoothing capacitor 5 are connected between the power input electrode Tvcc and the O port level input/output electrode Tgnd, and the DC power generated here is transferred to the IC module 1. It is also equipped with a waveform shaping circuit 6 that shapes the waveform of the alternating current obtained from the power input electrode Tvcc, and the output of this waveform shaping circuit 6 is sent to the external clock input terminal of the IC module 1 as an external clock signal. It is connected to the.

A rectifier circuit 7 for rectifying alternating current into direct current and a smoothing capacitor 8 are connected between the write power input electrode Tvpp and the O port level input/output electrode Tgnd, and the DC power generated here is connected to the IC module. 1
This is used as a power supply for writing to the EEFROM.

It is equipped with a phase comparison circuit 11 consisting of an exclusive OR circuit that compares the phase of the alternating current obtained from the reset signal input electrode Trst and the clock signal generated from the waveform shaping circuit 6, and the output of this phase comparison circuit 11 is as follows. , are connected to the reset signal input terminal of IC module l.

Between the data signal serial input/output electrode Ti10 and the I10 circuit, there is a first phase comparator circuit 12 which operates when a signal is input and which compares the phases of the clock signal and the input signal and a transmission Φ gate 13. series circuit,
and an exclusive type that operates when a signal is output, phase modulates the output signal in synchronization with the clock signal, and outputs the phase modulated signal.
A second series circuit consisting of a phase modulation circuit 14 and a transmission gate 15 formed of an OR circuit is connected.

On the other hand, the reader/writer is provided with a plate-shaped electrode 19 that faces each plate-shaped electrode 2 embedded in the IC card, and each plate-shaped electrode 18 of the reader/writer and each plate-shaped electrode 2 of the IC card are provided.
When they are brought close to each other, they are connected in an alternating current manner through the capacitance formed between them, allowing the IC card to exchange and process data.

(Other Embodiments) In the embodiments described above, an IC module consisting of a microprocessor and a memory chip is provided in the IC card, but it can also be applied to an IC module provided with only a memory chip. , data can be written and read via the plate-shaped electrode 2 embedded within the card.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the IC card of the present invention, FIG. 2 is a block diagram showing an example of the circuit inside the IC card of the present invention, and FIG. 3 is an external appearance of a conventional IC card. FIG. 4 is a block diagram of a conventional IC card. 1...IC module 2...Plate electrode 3...Plastic card holder Figure 3rd day Figure 4

Claims (2)

[Claims] (1) An IC card characterized in that an IC module and a plurality of plate-shaped electrodes each connected to the circuit elements of the IC module are provided in a plastic card. (2) It is characterized by comprising a circuit that rectifies the AC power applied to some of the plate-shaped electrodes to obtain power for the IC module, and a circuit that shapes the waveform of the AC power to obtain clock pulses. An IC card according to claim 1.