JP2934550B2 - Contactless IC card and fee collection system using contactless 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 contactless IC card particularly applied to toll collection with identification of a moving object, and a toll collection system using a noncontact IC card.

[0002]

2. Description of the Related Art In recent years, in toll collection systems for toll roads, there has been an attempt to use a non-contact IC card to settle tolls without stopping vehicles at a toll booth or preparing cash. Each company is frequently implemented.

FIG. 5 shows a toll collection system of this type, that is, a toll collection system for a toll motorway using a non-contact IC card. In the figure, reference numeral 31 denotes a tollgate antenna for communicating with non-contact IC cards 33A and 33B carried by a user of the toll road 32 by radio signals. This non-contact IC card 33
A and 33B store information such as a user number unique to the user (or the vehicle 34A or 34B on which the user rides). In addition, the non-contact IC cards 33A and 33B
It may be affixed, for example, inside the windshield of the vehicles 34A, 34B.

[0004] Tollgate antenna 31 and contactless IC card 3
The wireless communication between the non-contact IC cards 33A and 33B is carried out by a vehicle 3 carrying a non-contact IC card 33A or 33B.
4A, 34B) is in the communicable area (wireless communicable area) 3
This becomes possible when the vehicle enters the area 5.

Reference numeral 36 denotes a tollgate computer installed at the unmanned tollgate 37. The tollgate calculator 36 receives information such as a user number and an issued tollgate number communicated from the non-contact IC cards 33A and 33B via the tollgate antenna 31, calculates a withdrawal amount, and provides the user with a withdrawal amount. Claim. Upon receipt, the central computer 39 is installed in the central management center 38 and connected to the tollgate computer 36 by a communication line or the like.
In this system, the withdrawal amount is communicated to the customer, and based on this, the pass-through fee is automatically settled from the user's bank account or the like.

FIG. 6 shows a specific configuration of a conventional toll gate unit in a conventional toll collection system and a contactless IC card for performing a wireless communication sequence with this unit.
Shown in

In FIG. 6, reference numeral 40 denotes a tollgate-side unit, a tollgate CPU 41 corresponding to the tollgate calculator 36 in FIG. 5, a transmitter (tollgate transmitter) 42, and a transmission antenna (tollgate transmission antenna). 43, a receiving antenna (tollgate receiving antenna) 44, and a receiver (tollgate receiver) 45. The transmitting antenna 43 and the receiving antenna 44 are both the tollgate antenna 3 in FIG.
Equivalent to 1.

On the other hand, 50 is a contactless IC card,
A PU (card CPU) 51, a radio communication analog unit 55 including a reception antenna (card reception antenna) 52, a transmission antenna (card transmission antenna) 53, and a carrier detection circuit 54; a transmission / reception data processing circuit 56; have.

Here, a procedure for transmitting data from the tollgate side unit 40 to the contactless IC card 50 in the configuration of FIG. 6 will be described. First, data output as an inquiry signal from the CPU 41 is modulated by the transmitter 42 and emitted from the transmission antenna 43 as a transmission wave (modulated wave, radio wave) 46. This is a non-contact IC
The signal is received by the receiving antenna 52 of the wireless communication analog unit 55 provided on the card 50, demodulated, and the data (serial data) is input to the transmission / reception data processing circuit 56.

The transmission / reception data processing circuit 56 includes an oscillation circuit 5
The serial data received by the receiving antenna 52 and demodulated is converted into parallel data and transmitted to the CPU 51.

Next, a procedure when the tollgate side unit 40 extracts data from the non-contact IC card 50 in the configuration of FIG. 6, for example, when a response signal is received will be described. First, the non-contact IC card 50 cannot have a built-in transmitter (by the radio law). For this reason, a carrier wave containing no data is transmitted from the tollgate side unit 40 (the transmission antenna 43 thereof) as the transmission wave 46, and this is transmitted to the reception antenna 52 in the non-contact IC card 50.
And modulates response data (response data converted from parallel data into serial data) output from the CPU 51 via the transmission / reception data processing circuit 56 using this carrier wave, The response signal of the non-contact IC card 50 is transmitted from the transmission antenna 53 on the reception wave 47 (for the tollgate unit 40).

By the way, the carrier detection circuit 54 in the radio communication analog section 55 detects the transmission antenna 43 when the non-contact IC card 50 (the vehicle carrying the user carrying it) enters the communicable area of the tollgate. The electric field strength of the carrier wave emitted from the non-contact IC card 50 side becomes sufficiently large, that is, the reception level becomes sufficient, the radio wave communication is enabled, and the vehicle enters the communicable area of the tollgate. An interrupt signal INT for notifying the CPU 51 of the fact is generated.

The CPU 51 receives the interrupt signal INT from the carrier detection circuit 54, and shifts from the idle state to the excitation (operation) state. The necessity of such control, that is, the reason why the CPU 51 is not always in the excited state is as follows. That is, the power consumption in the idle state and the power consumption in the excited state of the CPU 51 are larger than the power consumption in the excited state. By doing so, battery consumption is reduced and battery life is extended.

[0014]

However, in the conventional non-contact IC card 50 having the structure shown in FIG. 6, the oscillating circuit 57 always operates and oscillates, and during the card suspension period when the CPU 51 is suspended. However, there is a problem that large power is consumed.

A conventional non-contact IC having the structure shown in FIG.
In the card 50, the output of the carrier wave detection circuit 54 is the non-contact IC card 50 (the vehicle carrying the user carrying the card).
Has been used only to notify the CPU 51 that has entered the communicable area. That is, the carrier wave detection circuit 54
After the CPU 51 was once operated, this output was not used at all in the subsequent communication sequence. For this reason, conventionally, the non-contact IC card 50 moves together with the vehicle in the communicable area, and the reflector 48a such as a road surface or a vehicle.
The communication sequence has been performed even if a reflected wave 49a different from the transmission wave 46 is generated due to the influence of the above and the apparatus enters a fading point where the electric field strength is reduced. However, since the electric field strength has decreased, the toll gate side unit 40
A transmission wave 46 from (the transmission antenna 43 of) a non-contact IC
In some cases, the card 50 could not be received, which was a problem.

By the way, even when the non-contact IC card 50 is in the communicable area, the reflector 4 such as a road surface or a vehicle may be used.
At the point where a reflected wave 49b different from the received wave 47 is generated due to the influence of 8b, the electric field strength is reduced by fading as in the case of the above-described transmitted wave 46. However, conventionally, since the communication sequence was performed irrespective of such a decrease in the electric field strength, there was a problem that a communication sequence for normal toll collection could not be performed. The present invention is their purpose has been made in view of the above circumstances, the non-contact IC card Best power consumption can be reduced in the card hibernation
And a toll collection system using a contactless IC card .

Another object of the present invention is to detect a fading point at which the reception level decreases on the contactless IC card side, and at such a point, suppress communication with the toll booth. A contactless IC card that can always realize communication for stable toll collection and
An object of the present invention is to provide a toll collection system using a contactless IC card .

Still another object of the present invention is that even if the electric field strength is reduced due to the movement of the non-contact IC card to a point where fading occurs, the state is detected at the toll booth and the communication sequence is not entered. By doing so, it is an object of the present invention to provide a toll collection system that can always realize stable communication for toll collection.

[0019]

According to the present invention, there is provided a contactless IC card provided with an oscillation control circuit for controlling the operation of an oscillation circuit for generating an operation clock for transmitting and receiving data processing. The first configuration is characterized in that the oscillation circuit is oscillated only in the card excitation state without performing the operation.

[0020] In addition, the non-contact IC card of the present invention, the above-mentioned
In addition to the first configuration, the carrier detection circuit for detecting the carrier wave received by the receiving antenna, the carrier level monitor for monitoring the reception level of the detected carrier by the carrier detection circuit, in the card hibernation Transport
Card excited state according to carrier detection by wave detection circuit
Switch, and the carrier wave
Predetermined carrier receiving level monitored by Berumonita there is the carrier receiving level in the absence or exceeds a predetermined level
Communication sequence with the toll booth unit until it exceeds the level
Also, the present invention is characterized in that a configuration (second configuration) including a control unit (second control unit) for suppressing the impedance is provided.

Next, in the toll collection system of the present invention, the toll booth unit is provided with the non-contact I
A field strength meter for measuring the field strength of the reception wave from the C card, and the field strength measured by the field strength meter is predetermined.
In a state where the electric field strength is lower than the predetermined value , a means (first control means) for suppressing a communication sequence with the non-contact IC card until the electric field strength becomes equal to or more than the predetermined value is provided, and the electric field strength is measured by the electric field strength meter. in a state where the electric field strength becomes lower than a predetermined value, without entering the communication sequence with the non-contact IC card, the configuration from which the field intensity falls first communication sequence moves the IC card in a region equal to or greater than a predetermined value (third Configuration).

[0022]

In the first configuration, the oscillation circuit does not operate under the control of the oscillation control circuit when the non-contact IC card (CPU) is at rest, and the non-contact IC card (CPU) is excited. It operates only when it is in the (operation) state and outputs an operation clock. Therefore, power consumption in the card rest state can be reduced.

Further, in the second configuration, the non-contact I
The reception level of the carrier detector in the C card is constantly monitored by a carrier level monitor provided in the card. Then, when the monitored carrier wave reception level is not higher than the predetermined level, communication with the toll gate is suppressed even if the carrier wave detector once notifies that the vehicle has entered the communicable area. On the other hand, when the monitored carrier wave reception level becomes equal to or higher than the predetermined level, the data reception enable signal is output to the tollgate side with the transmission wave from the tollgate being sufficiently received. After receiving the data receivable signal, the tollgate transmits data to the contactless IC card. Therefore, the tollgate can determine whether or not the contactless IC card is in a state where data can be transmitted and received correctly, based on whether or not the data receivable signal has been transmitted from the contactless IC card.

Next, in the third configuration, the electric field strength meter provided on the tollgate side measures the electric field strength of the wave received from the non-contact IC card. The toll booth always monitors the measured value of the electric field strength meter, and if the measured value is smaller than a predetermined value, it does not output a question (inquiry) signal, that is, does not enter the communication sequence, and If the measured value is equal to or greater than the predetermined value, it is determined that the electric field strength of the received wave is sufficient, a question (inquiry) signal is output, and the communication sequence for preparing a response signal from the non-contact IC card is started.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, in which the present invention is applied to a toll collection system in an unmanned tollgate on a toll road.

FIG. 1 is a block diagram showing the configuration of a toll booth unit and a contactless IC card for performing a wireless communication sequence with the unit in the toll collection system according to one embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a tollgate side unit,
Reference numeral 20 denotes a non-contact IC card. Toll booth unit 10
Is a tollgate CPU 11, a transmitter (tollgate transmitter) 12 for modulating and transmitting data output from the tollgate CPU 11, and a transmission signal from the transmitter 12 as a transmission wave 1.
6 has a transmitting antenna (tollgate transmitting antenna) 13 for output.

The toll booth unit 10 also includes a non-contact IC
A receiving antenna (tollgate receiving antenna) 14 for receiving a reception wave 17 from the card 20, a receiver (tollgate receiver) 15 for demodulating the received data and outputting it to the tollgate CPU 11, and a receiver 15 It has an electric field strength meter 18 that measures the electric field strength of the received wave and notifies the tollgate CPU 11 of the result.

On the other hand, the non-contact IC card 20 has a CPU (card CPU) 21 at the center of the card 20 and a receiving antenna (card receiving antenna) for receiving the transmission wave 16 from the toll gate unit 10. ) 22, a radio communication analog including a transmitting antenna (card transmitting antenna) 23 for emitting a receiving wave 17 to the tollgate side unit 10 and a carrier detecting circuit 24 for detecting a carrier received by the receiving antenna 22 It has a part 25. When detecting that the electric field strength of the carrier has become sufficiently large, the carrier detection circuit 24 outputs an interrupt signal INT to the CPU 21.

The non-contact IC card 20 converts the serial reception data received and demodulated by the reception antenna 22 into parallel data and outputs the parallel data to the CPU 21, and converts the parallel transmission data output from the CPU 21 into serial data. Transmission / reception data processing circuit 26 which converts the data into transmission data and outputs it to transmission antenna 23 side;
The oscillation circuit 27 according to the oscillation control signal OSCC from
Has an oscillation control circuit 28 for controlling the operation of the control circuit, and a carrier wave level monitor 29. The carrier wave level monitor 29 monitors the reception level of the carrier wave detected by the carrier wave detection circuit 24 and outputs the monitoring result to the CPU 21.

FIG. 2 shows the internal configuration of the oscillation circuit 27 and the oscillation control circuit 28 of FIG. As shown in FIG. 2, the oscillation circuit 27 includes an oscillator 271 for determining an oscillation frequency,
It comprises a resistor 272 and capacitors 273 and 274. The oscillation control circuit 28 includes a NAND (NAND) gate 281 and controls the oscillation of the oscillation circuit 27 according to an oscillation control signal OSCC from the CPU 21.

Next, the operation of one embodiment of the present invention will be described with reference to the flowcharts of FIGS. 3 is a flowchart for explaining the operation of the CPU 21 of the non-contact IC card 20, and FIG. 4 is a flowchart for explaining the operation of the CPU 11 of the tollgate unit 10.

First, from the transmitting antenna 13 of the tollgate side unit 10, a carrier wave containing no data is transmitted by the transmitting wave 1
6 is transmitted. In this state, the non-contact IC card 2
0 (vehicle on which the user carrying the vehicle) enters the communicable area of the tollgate, the receiving antenna 1 in the card 20
At 2, the transmission wave 16 from the toll gate unit 10 is received.

The carrier detection circuit 24 detects that the non-contact IC card 20 has entered the communicable area,
When the electric field strength of the carrier wave detected from the transmission wave 16 received in step 2 becomes sufficiently large, that is, when the wireless communication with the toll gate side unit 10 becomes possible, the CPU 21 informs the entry into the communicable area of the toll gate. , An interrupt signal INT is generated.

When the CPU 21 receives the interrupt signal INT from the carrier wave detection circuit 24, it shifts from the idle state to the excited state. Then, the CPU 21 outputs a high-level oscillation control signal OSCC to the oscillation control circuit 28. This oscillation control signal OSCC is input to the NAND gate 281 of the oscillation control circuit 28. Then, the NAND gate 281
By this output, the oscillating operation of the oscillating circuit 27 composed of the oscillator 271, the resistor 272 and the capacitors 273 and 274 is permitted, and the generation of the operation clock of the frequency determined by the oscillator 271 is started. The oscillation operation of the oscillation circuit 27 is stopped when the CPU 21 shifts from the excitation state to the sleep state and the oscillation control signal OSCC is returned to the low level by the CPU 21. That is, the oscillation circuit 27
The oscillation operation is permitted by the CPU 21 only during the period in which the PU 21 is in the excited state, and an operation clock is generated. With this operation clock, the transmission / reception data processing circuit 26 becomes operable.

The carrier level monitor 29 constantly monitors the reception level of the carrier detected by the carrier detection circuit 24, and notifies the CPU 21 of the monitored value. The CPU 21 always refers to the value of the carrier wave reception level monitored by the carrier wave level monitor 29 in the excited state, and performs communication (communication sequence) with the toll gate side unit 10 when the value is not more than a predetermined value. Refrain (step S1). Such a state occurs because, for example, the non-contact IC card 20 moves together with the vehicle in the communicable area, and a reflected wave different from the transmission wave 16 is generated due to the influence of a reflector such as a road surface or a vehicle. However, this is a case where a fading point at which the electric field strength decreases is entered.

When the non-contact IC card 20 (the vehicle carrying the user carrying the card) escapes from such a fading point within the communicable area, and the value of the carrier wave reception level becomes a predetermined value or more, the CPU 21 proceeds. Then, data for transmitting a data receivable signal to the tollgate side unit 10 is output to the wireless communication analog unit 25 via the transmission / reception data processing circuit 26 (step S2). As a result, the data from the CPU 21 is modulated using the carrier received by the receiving antenna 22 in the wireless communication analog unit 25, and the received signal is put on the received wave 17 by the transmitting antenna 23 as a data receivable signal. It is transmitted to the local unit 10. At this time, the CPU 21 immediately switches to the reception mode and prepares for a response signal from the tollgate unit 10 (step S3).

A reception wave 17 from the non-contact IC card 20 (the transmission antenna 23 therein) is received by the reception antenna 14 in the tollgate side unit 10. The reception wave 17 received by the reception antenna 14 is demodulated by the receiver 15 and output to the tollgate CPU 11. An electric field strength meter 18 is connected to the receiver 15. The electric field strength meter 18 is connected to the receiver 1
5, the electric field strength of the received wave 17 demodulated is measured, and the measured value is notified to the tollgate CPU 11.

The tollgate CPU 11 constantly monitors the value measured by the electric field strength meter 18, and if the value is not equal to or greater than a predetermined value, refrain from communicating with the tollgate unit 10 (communication sequence) (step S11). S11). Such a state occurs because, for example, the non-contact IC card 20 moves together with the vehicle in the communicable area, and a reflected wave different from the received wave 17 is generated due to the influence of a reflector such as a road surface or a vehicle. And
This is a case where a fading point at which the electric field strength is reduced is entered.

Eventually, the non-contact IC card 20 (the vehicle carrying the user carrying it) escapes from such a fading point in the communicable area, and the electric field intensity value of the received wave 17 measured by the electric field intensity meter 18 Is greater than or equal to a predetermined value, the tollgate CPU 11
Data for transmitting an inquiry (inquiry) signal to the transmitter 12 is transmitted to the transmitter 12 for modulation, and transmitted as a query signal to the non-contact IC card 20 on the transmission wave 16 by the transmission antenna 13 (step S12). ). And tollgate C
The PU 11 immediately prepares for a response signal from the non-contact IC card 20 (step S13).

Transmission antenna 13 of tollgate unit 10
The interrogation signal transmitted on the transmission wave 16 is received by the reception antenna 22 of the non-contact IC card 20, demodulated, and input to the CPU 21 through the transmission / reception data processing circuit 26. When receiving the interrogation signal from the tollgate unit 10, the CPU 21 transmits a response signal to the interrogation signal on the reception wave 17 to the tollgate unit 10 in the same manner as in the case of transmitting the data receivable signal. I do. This response signal is transmitted at a point avoiding the fading point, has a sufficient electric field strength, and can perform reliable communication.

In the above embodiment, the non-contact IC card 20 is described as being carried by the user. However, the non-contact IC card 20 may be used by attaching it to the inside of a vehicle, for example, a windshield.

In the above embodiment, the case where the present invention is applied to a toll collection system at an unmanned toll booth on a toll road has been described. The present invention can be applied to an entire moving object identification system using a non-contact IC card required for the present invention.

[0044]

As described above in detail, according to the present invention, an oscillation control circuit for controlling the operation of an oscillation circuit built in a non-contact IC card is provided, and the oscillation circuit is controlled only when the non-contact IC card is excited. Oscillation is performed, so non-contact I
The power consumption of the C card in the idle state can be greatly reduced.

Further, according to the present invention, a fading point at which a carrier wave receiving level is reduced in a non-contact IC card is detected, and at such a point, communication with a toll gate is suppressed. Therefore, communication can be performed while avoiding a point where the electric field strength is reduced due to fading, and toll collection can be performed through a stable wireless line.

According to the present invention, an electric field strength meter for measuring the electric field strength of the received wave from the non-contact IC card is provided at the tollgate, and the electric field strength measured by the electric field strength meter is predetermined. Since the communication sequence with the non-contact IC card is executed only in a state where the value is equal to or more than the value, even if the non-contact IC card moves to a point where fading occurs, the communication sequence does not enter even if the electric field strength is reduced. Communication can be performed at the point when the point has passed, so that the toll collection can always be performed through a stable wireless line.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a contactless IC card that performs a wireless communication sequence with a toll gate unit and a wireless communication unit in the toll collection system according to one embodiment of the present invention.

FIG. 2 is a diagram showing an internal configuration of an oscillation circuit 27 and an oscillation control circuit 28 in FIG.

FIG. 3 is a flowchart for explaining the operation of a CPU (card CPU) 21 in the non-contact IC card 20 of FIG.

FIG. 4 is a flowchart for explaining the operation of a CPU (tollgate CPU) 11 in the tollgate-side unit 10 of FIG.

FIG. 5 is a diagram showing a general system configuration of a toll vehicle toll collection system to which a contactless IC card is applied.

FIG. 6 is a block diagram showing a configuration of a conventional tollgate-side unit and a contactless IC card in a toll collection system.

[Explanation of symbols]

10 ... Tollgate side unit, 11 ... Tollgate CPU, 12 ...
Tollgate transmitter, 13: tollgate transmission antenna, 14: tollgate reception antenna, 15: tollgate receiver, 16: transmission wave,
17 reception wave, 18 electric field strength meter, 20 non-contact IC card, 21 card CPU, 22 card reception antenna, 23 card transmission antenna, 24 carrier wave detection circuit, 25 radio communication analog unit, 26 ... Transmission / reception data processing circuit, 27 ... oscillation circuit, 28 ... oscillation control circuit, 29 ...
Carrier level monitor, 271, oscillator, 281, NAND gate, INT, interrupt signal, OSCC, oscillation control signal.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Yasui 1-1 1-1 Wadazakicho, Hyogo-ku, Kobe City, Hyogo Pref. Mitsubishi Heavy Industries, Ltd. 1-1-1 Wadasaki-cho, Hyogo-ku Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) References JP-A-4-64189 (JP, A) JP-A 2-2476 (JP, A) 199363 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06K 19/07 G06K 17/00

Claims (2)

(57) [Claims] 1. A toll booth unit having a transmitting and receiving antenna.
To collect tolls within the wireless communication area
Contactless IC card that performs communication sequence by
Of data transmitted and received in the wireless communication sequence.
The car of the operation and an oscillation circuit for generating a clock, card hibernate and card excited state for processing
Oscillation control that causes the oscillation circuit to oscillate only in the
Control circuit and the tollgate side unit received by the receiving antenna
A carrier detection circuit for detecting the carrier wave, and a reception level of the carrier detected by the carrier detection circuit.
A carrier level monitor for monitoring a bell, and the carrier detection circuit in the card rest state.
Switch to the card excitation state according to the carrier detection,
In the card excitation state after switching the
The carrier reception level monitored by the
If the carrier reception level does not exceed the
Communication sequence with the toll booth unit until
Control means for suppressing the
Non-contact IC card. 2. A contactless IC card and a toll gate unit
Between the wireless communication areas to collect tolls
Toll collection for non-contact IC card that performs communication sequence
In the receiving system, a carrier wave is usually transmitted to the toll gate side unit to communicate with the non-contact IC card.
Sometimes tollgate transmission where data is transmitted on the carrier wave
And the electric field strength of the received wave from the non-contact IC card.
A field strength meter for measurement, and
In the state where the applied electric field strength is lower than the predetermined value,
Until the electric field strength exceeds the predetermined value,
First control means for suppressing the communication sequence with the
And the non-contact IC card stores data transmitted and received in the wireless communication sequence.
An oscillation circuit for generating an operation clock for processing;
Card out of the idle state and card excited state
An oscillation control circuit that causes the oscillation circuit to oscillate only in the active state
Road and the tollgate side unit received by the receiving antenna
A carrier detection circuit for detecting a carrier from
Reception level of carrier detected by carrier detection circuit
Monitoring the carrier level and the card idle state
According to the carrier detection by the carrier detection circuit in
Switch to the card excited state, and the car after the switch
Monitored by the carrier level monitor in the excited state.
In the state where the carrier reception level is not above a predetermined level.
Is before the carrier reception level becomes higher than the predetermined level.
Second to suppress the communication sequence with the toll gate unit
Contactless IC car provided with a control means
Toll collection system.