JP2942809B2 - Non-contact IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type IC card having no contact terminals for inputting and outputting power and signals.
In particular, the present invention relates to a non-contact type IC card which can reduce the load on the external device even when the card enters and exits an area accessible to the external device a plurality of times at short time intervals.

[0002]

2. Description of the Related Art There is known an IC card which does not have a contact terminal, receives a signal from outside via magnetic coupling or capacitive coupling with an external device, or outputs a signal to an external device. . Such a non-contact type IC card is
Compared with the method of transmitting and receiving signals by the contact terminals, for example, the data stored in the card can be read out to the external device when the card holder approaches the external device while holding the IC card in his hand. Therefore, the reading operation is easy. Further, unlike the data input / output via the contact terminals, there is no problem of contact failure due to dirt or corrosion of the terminal joint or malfunction due to leak current.

[0003] A non-contact type IC card requires a card holder to bring the card close to the reading device while holding the card, and it is not necessary to insert the card into the reading device and perform a reading operation. It is suitable for checking when a large number of people pass one after another, such as when used as a check key for entering or leaving a specific room.

In such a non-contact type IC card, for example, when used as a commuter pass or a key for checking in / out, ID data is read from a memory of the IC card by a reader / writer and collated. If the collation results match, the passage of the ticket gate and entry to the room are permitted. At the same time, the used history data is written into the memory of the IC card.

[0005]

In a non-contact type IC card, the above-described collation and writing of history are performed by entering an area accessible to a reader / writer, and the accessible area has a certain size. For example, when used as a commuter pass, the same card may be inserted twice or more in an area accessible to a reader / writer installed in a ticket gate depending on the operation of the holder. That is, the holder puts the card into the area,
After leaving the area, you may be able to enter the area again.
In such a case, it is necessary not to write the history in the second access.

Conventionally, in such a case, the reader / writer detects the second access to the same card and inhibits writing of new data to the card. However, at the ticket gate, it is necessary to check the passage of many cards in a short period of time, so the reader / writer must wait immediately after the access of the card for the next card to pass. I can't afford to check that there is.

[0007] Therefore, it is desired that the card functions so that operation is prohibited for a certain time after passing through the ticket gate. However, in a card having no power supply inside, that is, a so-called external power supply type card, a DC voltage required in an internal circuit is obtained by rectifying electromagnetic energy supplied from the outside. Therefore, it is difficult to control the operation prohibition for a certain time after the supply of energy from the outside has stopped. For example, after the supply of energy from the outside is cut off, the circuit inside the card can be operated using the energy from the discharge of the charge stored in the smoothing capacitor of the power supply circuit, but the current consumed by the circuit The operation of the circuit is affected by the energy stored in the capacitor and the smoothing capacitor, so that it is difficult to set the operation inhibition time.

The present invention solves the above problems,
It is an object of the present invention to provide a non-contact type IC card capable of reducing the load on the external device even when the card enters and exits an area accessible to the external device a plurality of times at short time intervals.

[0009]

According to the present invention, a non-contact type IC card for exchanging signals with an external device without contact is provided with a main circuit means for performing various operations based on the function of the IC card. An operation prohibition signal generating means for generating an operation prohibition signal for prohibiting the operation of the main circuit means for a predetermined time; and a control means for controlling the main circuit means and the operation prohibition signal generating means. When the operation of the means is completed, the operation inhibiting signal generating means is operated, and the operation of the main circuit means is inhibited for a predetermined time by the operation inhibiting signal from the operation inhibiting signal generating means.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a non-contact type IC card according to the present invention.

FIG. 1 shows an embodiment of a non-contact type IC card according to the present invention. This IC card is an external power supply type IC card that receives power supply from outside. Parts not directly related to the present invention are not shown.

This card has a power supply circuit 10. The power supply circuit 10 is a power supply circuit that sends power supplied from the reader / writer to each part of the card. The power supply circuit 10 is coupled to the reader / writer by magnetic coupling (not shown) or capacitive coupling (not shown), and receives power supply from the reader / writer.

A main circuit 16 is connected to the power supply circuit 10. The main circuit 16 is a circuit that performs an operation based on various functions of the card, and includes a CPU, a memory, and the like. When the card enters the area accessible by the reader / writer by the holder, the main circuit 16 reads ID data from a memory (not shown) and outputs the ID data to the reader / writer, or stores ID data sent from the reader / writer in the memory. It has a function to collate with the data. As a result of such collation of the ID data, the main circuit 16 also permits the passage of the holder by the reader / writer, and then writes in the memory that the passage is permitted by data sent from the reader / writer.

The power supply circuit 10 is further connected to a re-access prohibition time setting circuit 12. The re-access prohibition time setting circuit 12 sets the re-access prohibition time based on the voltage supplied from the power supply circuit 10 and the control signal sent from the control circuit 14, and outputs a re-access prohibition time setting signal to the control circuit 14.

The control circuit 14 is connected to the re-access prohibition time setting circuit 12 and the main circuit 16, and controls the operation of the main circuit 16 for a predetermined time based on the re-access prohibition time setting signal output from the re-access prohibition time setting circuit 12. Prohibit. The control circuit 14 also controls the setting operation of the re-access prohibition time setting circuit 12 based on the access operation end signal sent from the main circuit 16.

FIG. 2 shows a more specific configuration of the circuit of FIG. As components corresponding to the power supply circuit 10 of FIG. 1, four diodes D1, D2, D3, D4, two capacitors C1, C2 and a regulator 20 are provided. The power energy supplied from the reader / writer through the coil L is rectified by the diodes D1, D2, D3, D4 and the regulator 20, and the capacitors C1, C2
, And is sent to the main circuit 16 and the re-access prohibition time setting circuit 12.

The re-access prohibition time setting circuit 12 has a transistor Q. The emitter of the transistor Q is connected to the output of the power supply circuit 10, and the base of the transistor Q is connected to the output of the power supply circuit 10 via the resistor R2 and to the output of the control circuit 14 via the resistor R4. The collector of the transistor Q is connected to the anode of a diode D5, and the cathode of the diode D5 is connected to a resistor R1 and a capacitor C3. The other terminals of the resistor R1 and the capacitor C3 are grounded. The cathode of the diode D5 is further connected to the gate of the N-channel FET 24. The drain of the FET 24 is connected to the output of the power supply circuit 10 via the resistor R3 and to the Schmitt trigger circuit 22, and the source of the FET 24 is grounded. The output of the Schmitt trigger circuit 22 is
Connected to the input.

The operation of the re-access prohibition time setting circuit 12 will be described with reference to the timing chart of FIG. The re-access prohibition time setting circuit 12 sets a prohibition time for prohibiting the second access when the card is used, for example, as a commuter pass and enters the accessible area of the reader / writer twice in a short time in a ticket gate. To set.

At the point A in FIG. 2, power as shown in FIG. That is,
When the card enters the area accessible by the reader / writer twice (time t1 and t4), energy is supplied from the reader / writer through the power supply circuit 10, respectively. When power is supplied to the point A, the power is supplied to the main circuit 16, and the main circuit 16 operates. During operation of the main circuit 16,
As shown in FIG. 3B, power is supplied to the main circuit 16,
A signal B indicating that the main circuit 16 is operable is supplied from the control circuit 14 to the base of the transistor Q via the resistor R4 (time t1). Therefore, since the transistor Q is in a non-conductive state, the power supplied to the point A is not supplied to the point C, and the potential at the point C is at the ground level as shown in C of FIG. Therefore, since no signal is input to the gate of the FET 24, the FET 24 is in a non-conductive state.
The output of the power supply circuit 10 is supplied as shown in FIG. Thus, the output of the Schmitt trigger circuit 22 also becomes as shown in FIG. 3E, and this output E is sent to the control circuit 14. The control circuit 14 outputs a signal to permit the operation of the main circuit 16 to the main circuit 16 according to the output E.

When the operation of the main circuit 16 is completed (at time t)
2), the signal B is no longer output from the control circuit 14, whereby the base of the transistor Q becomes low level, the transistor Q conducts, and the potential at the point C rises as shown in FIG. 3C. At time t3, when power supply A from the power supply circuit 10 stops, the power supply circuit
However, the power at point C is gradually reduced in accordance with the time constant of CR as shown by C in FIG. 3 due to the discharge of the electric charge stored in the capacitor C3 when the power is supplied.

At time t4, when the card enters the accessible area of the reader / writer again and the power is supplied for the second time from the power supply circuit 10, a signal B indicating that power can be supplied to the main circuit 16 is output. The signal is sent from the control circuit 14 to the transistor Q, and the transistor Q is turned off. Therefore, the state where power is not supplied from the power supply circuit 10 continues at the point C, and the potential at the point C continues to decrease as shown in FIG. As a result, the potential input to the gate of the FET 24 continues to decrease, and the current flowing from the drain to the source of the FET 24 decreases, so that the potential at the point D gradually increases. Therefore, the voltage D input to the Schmitt trigger circuit 22 gradually increases, and at time t5 when the voltage D exceeds a predetermined value, the Schmitt trigger circuit 22
Outputs a signal E. The control circuit 14 outputs a signal for permitting the operation of the main circuit 16 to the main circuit 16 according to the output E.

After the output E of the Schmitt trigger circuit 22 becomes high level, the operation of the main circuit 16 is permitted. Therefore, the first main circuit 1 at time t2
After the operation 6 (access with the reader / writer) is completed, the time t5
Until the operation of the main circuit 16 is not permitted, the power supply circuit 1 enters the card accessible area at time t4.
Even when power is supplied from 0, the main circuit 16 does not operate. In this way, access to the reader / writer can be prohibited for a certain time after the end of the first access.

Next, the operation of the control circuit 14 will be described with reference to the flowchart of FIG. It is determined whether or not the power is supplied (step 102). If the power is not supplied, the process waits until the power is turned on. If power is being supplied, it is determined that the card has entered an area accessible to the reader / writer, and it is determined whether or not the above-described re-access prohibition period is in progress (step 10).
4). If it is during the re-access prohibition period, it is determined whether or not the power is turned off (step 106). If the power is not turned off, the process waits until the power is turned off. When the power is turned off, it is determined that the card has left the area accessible to the reader / writer, and the process returns to the first step 102.

If it is not during the re-access prohibition period in step 104, it is determined that access to the reader / writer has become possible, and predetermined data communication is performed with the reader / writer (step 108). It is determined whether or not the data communication has been completed (step 110), and if completed, a re-access prohibition period is set (step 112). Thereafter, it is determined whether the power has been turned off (step 1).
14) If the power is not turned off, wait until the power is turned off. When the power is turned off, it is determined that the card has left the area accessible to the reader / writer, and the process returns to the first step 102.

In step 110, it is determined whether or not the power is turned off even when the data communication is not completed (step 116). If the power is turned off, the process returns to step 102.

As described above, according to the card of this embodiment,
After the access is completed, re-access can be prohibited for a certain period of time. Therefore, when the card enters the area accessible to the reader / writer two or more times in a short time, the second and subsequent accesses to the reader / writer are prohibited, so that inconvenience caused by multiple accesses can be eliminated. it can. Further, since the card has a function of prohibiting access, it is not necessary to perform an operation of prohibiting re-access with the card in the reader / writer, and the burden on the reader / writer can be reduced.

According to this card, for example, when it is necessary to check the passage of a large number of cards in a short time at the ticket gate, the reader / writer does not need to check for re-access. It is possible to wait for the next card to pass, so that access to a large number of cards can be performed smoothly.

Although the above embodiment has been described with respect to an external power supply type, the present invention can be applied to a non-contact type IC card having a power supply therein.

[0029]

According to the present invention, when the operation of the main circuit means is completed, the operation prohibition signal generating means operates to generate an operation prohibition signal, thereby prohibiting the operation of the main circuit means for a predetermined time. Therefore, when the card enters the area accessible to the external device a plurality of times in a short time, the second and subsequent accesses can be prohibited, so that the inconvenience due to the plurality of accesses can be eliminated. Also,
Since it is not necessary for an external device to monitor such prohibition of access, the load on the external device can be reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing one embodiment of a non-contact type IC card according to the present invention.

FIG. 2 is a circuit diagram showing a specific example of the card of FIG.

FIG. 3 is a timing chart showing the operation of the circuit of FIG.

FIG. 4 is a flowchart illustrating an operation of the control circuit of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Power supply circuit 12 Re-access prohibition time setting circuit 14 Control circuit 16 Main circuit 22 Schmitt trigger circuit 24 FET

Claims (3)

(57) [Claims] 1. A non-contact type IC card for transmitting and receiving signals to and from an external device in a non-contact manner, the card comprising: main circuit means for performing various operations based on functions of the IC card; An operation prohibition signal generating means for generating an operation prohibition signal for prohibiting the operation of the main circuit for a predetermined time; and control means for controlling the main circuit means and the operation prohibition signal generating means. The operation of the main circuit means is prohibited for a predetermined time by the operation prohibition signal from the operation prohibition signal generating means.
C card. 2. The card according to claim 1, further comprising power supply circuit means for receiving power from outside and supplying power to each part of said card, wherein said main circuit means and operation prohibition are provided. A non-contact type IC card, wherein the signal generating means operates by receiving power supply from the power supply circuit means. 3. The card according to claim 2, wherein the operation prohibiting signal generating means stores power supplied from the power supply circuit means and discharges the power according to a predetermined time constant. And a Schmitt trigger circuit for outputting the operation inhibition signal when the voltage obtained from the voltage inversion means is equal to or less than a predetermined value. Non-contact type IC card.