JPH09298486A - Non-contact data transmission / reception method and device - Google Patents

Abstract

(57) Abstract: When the interrogator 1 transmits a signal modulated by ASK, it is impossible to increase the bit rate in the communication from the interrogator to the responder to increase the speed, and also the responder. Even if communication is performed using only the coil in the resonance circuit of No. 2 or the resonance circuit having a sufficiently low Q value, the amplitude of the received waveform becomes small, and a sufficient power supply voltage for operating the IC in the responder 2 can be obtained. It was impossible. A carrier for power supply and a carrier for command data are alternately transmitted from an interrogator, and the carrier for power supply has a constant frequency and is composed of a predetermined wave number, and also for command data. The carrier wave of has a frequency of a predetermined multiplication factor with respect to the carrier wave for power supply, while the responder receives the carrier wave for power supply by increasing the Q value of the resonance circuit of the responder and receives the carrier wave for command data. The carrier wave is received by lowering the Q value of the resonant circuit of the transponder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contactless card or other answering device attached to a tool or baggage, or held by a person, for contactless contact in a factory production line or distribution line, office entry / exit control, etc. The present invention relates to a non-contact data transmission / reception device that communicates and manages data with.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a circuit configuration of a conventional non-contact data transmitting / receiving apparatus, and FIG. 6 is a timing chart showing a demodulation impossible state in the ASK system. In FIG. 5, reference numeral 1 is an interrogator, and 2 is a responder that communicates with the interrogator 1 in the communication area 3. The interrogator 1 includes an oscillator 4, a modulator 5, a transmitter 6, a receiver 7, a demodulator 8 and a controller 9. The responder 2 includes a receiving unit 10, a power supply circuit 11, a demodulating unit 12, a control unit 13, a memory 14, a modulating unit 15, and a transmitting unit 16. C2 is a power supply charging capacitor.

Next, the operation will be described. First, the interrogator 1 sends a high-frequency signal modulated by a command to the responder 2 in a non-contact manner. The command signal is a command (Amplitude Shift) for the responder 2.
It is a high frequency signal modulated by Keying). The responder 2 returns a unique ID code and data according to the command. In this case, the arrival area of the read signal from the interrogator 1 is defined as the communication area 3, and only the responder 2 in the communication area 3 is allowed to communicate. The responder 2 demodulates the command signal from the interrogator 1 received by the receiving unit by envelope detection, rectifies the high frequency signal, and charges the capacitor to be the internal power supply. The high frequency signal is also used as the internal clock of the transponder 2. Then, the ID code and data are read from the memory in the responder 2 according to the content of the command, and the high frequency signal is modulated and returned.
It should be noted that, as shown in FIG. 5, the IC is integrated into one chip except the antenna for transmitting and receiving and the capacitor for the power supply, and the size and thickness of the card are reduced.

As described above, in the conventional non-contact data transmitter / receiver, the modulation method used for communication from the interrogator 1 to the responder 2 is a demodulator in which the responder 2 is composed of an envelope detection circuit and a comparator. Since it is possible to demodulate the signal from the interrogator 1 into a digital value simply by mounting the unit, ASK having a simple circuit configuration is the mainstream. In the case of ASK, as shown in FIG. 6, a PNM (Plus Number Modulat) that distinguishes by the number of pulses so that the responder 2 can determine “0” and “1” of the digital data transmitted by the interrogator 1.
Ion) is used to demodulate digital data from the time and wave number of 1-bit envelope detection output.

However, since the transponder 2 also extracts the internal power source from the high frequency signal from the interrogator 1, in order to improve the reception efficiency, the transmitting / receiving antenna is composed of a resonance circuit having a high Q value. Therefore, the AS as shown in FIG.
When the interrogator 1 transmits the signal modulated by K, the responder 2
However, there is a problem that the vibration energy remains in the resonance circuit, demodulation by envelope detection cannot be performed, and the command transmitted from the interrogator 1 cannot be detected. To solve these problems, lower the bit rate of the signal transmitted from the interrogator 1,
It may be possible to set the transmission stop part (G in FIG. 6) to be long and sufficiently consider the residual vibration energy, but by doing so, increase the bit rate in the communication from the interrogator 1 to the responder 2 to increase the speed. Was impossible. Also only the coil,
Alternatively, it is conceivable to perform communication using a resonance circuit having a sufficiently low Q value, but the received waveform amplitude becomes small, and it is impossible to obtain a sufficient power supply voltage for operating the IC in the responder 2. It was necessary to mount electric parts such as batteries.

[0006]

As described above, the problem to be solved by the present invention is to increase the bit rate in communication from the interrogator to the responder when the interrogator 1 transmits a signal modulated by ASK. Therefore, even if communication is performed using only the coil in the resonance circuit of the transponder 2 or using the resonance circuit having a sufficiently low Q value, the received waveform amplitude becomes small and the transponder 2 That is, it is impossible to obtain a sufficient power supply voltage for operating the internal IC, and it is necessary to mount a live battery.

The present invention has been made in order to solve the above problems, and aims at speeding up the communication from the interrogator to the responder, and without reducing the received waveform amplitude in the responder. It is an object of the present invention to obtain a non-contact data transmission / reception method and a device thereof which secures a sufficient power supply voltage for operating the IC therein, and thereby does not require a battery to be mounted on a transponder.

[0008]

According to a first aspect of the present invention, there is provided a contactless data transmitting / receiving method, wherein a carrier for power supply and a carrier for command data are alternately transmitted from an interrogator and used for power supply. Has a constant frequency and is composed of a predetermined wave number, and the carrier for command data has a frequency of a predetermined multiplication factor with respect to the carrier for power supply, while the transponder has a frequency for power supply. The carrier wave is received by increasing the Q value of the resonance circuit of the responder, and the carrier wave for command data is received by decreasing the Q value of the resonance circuit of the responder.

The contactless data transmitting / receiving method according to the second aspect of the present invention is such that the digital value of the command data is displayed according to the wave number of the carrier wave for the command data.

According to the third aspect of the non-contact data transmitting / receiving method of the present invention, one bit is constituted by a set of a carrier wave for power supply and a carrier wave for the command data.

According to a fourth aspect of the present invention, there is provided a contactless data transmission / reception method in which a carrier wave for power supply is transmitted and then a plurality of carrier waves for command data are transmitted.

According to a fifth aspect of the non-contact data transmission / reception method of the present invention, a carrier for power supply and a carrier for command data are alternately transmitted from the interrogator, and the carrier for power supply has a constant frequency. The carrier wave for command data has a frequency of a predetermined multiplication factor with respect to the carrier wave for power supply, and the responder uses the carrier wave for power supply as a resonance circuit of the responder. After increasing the Q value of, receiving the carrier wave for command data by lowering the Q value of the resonance circuit of the responder, and transmitting the start text of a predetermined wave number when the interrogator starts communication. , Transmission for a predetermined time is stopped, then a carrier for power supply is transmitted, and then a carrier for command data is transmitted,
On the other hand, the responder receives the start text from the interrogator, compares the wave number of the received start text with the wave number of the start text sent by the preset interrogator, and determines the distance from the interrogator from the difference in the wave numbers. And the wave number of the carrier wave for electric power transmission to be received is corrected according to the difference in the wave number.

In the non-contact data transmitter / receiver according to the sixth aspect of the present invention, the interrogator has a command having a constant frequency and a frequency of a predetermined multiplication factor with respect to a carrier wave for power supply having a predetermined wave number. Transmitting means for alternately transmitting a carrier wave for data and a carrier wave modulated by the ASK method are provided, and a transponder is composed of a parallel resonance circuit of a coil and a capacitor, and transmits and receives a signal to and from the interrogator. Transmission / reception means, internal power supply means for converting the carrier wave for power supply from the interrogator into direct current, and using the direct current power as the internal power supply of the responder, and carrier wave demodulation for power for counting the wave number of the carrier wave for power supply Section and a command data demodulation section that detects the envelope of the carrier wave for command data and demodulates the command data from the interrogator,
A series circuit including a resistor and a switch that lowers the Q value of the parallel resonant circuit by the outputs of the power carrier demodulation unit and the command data demodulation unit is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a configuration of a responder 2 of a contactless data transmitter / receiver for realizing a contactless data transmitting / receiving method according to Embodiment 1 of the present invention, and FIG. 2 shows communication waveforms of an interrogator and a responder. It is a waveform diagram. The circuit configuration of the contactless data transmitter / receiver according to the present invention is the same as that of the block diagram of the conventional circuit configuration shown in FIG. The block diagram shown omits this and uses FIG. 5.

The transponder 2 has a parallel resonance circuit composed of L1 and C1 as a receiver, and receives a command from the interrogator 1 and a high frequency signal modulated by data to be written in the memory 14. Here, the resonance frequency of the resonance circuit is set to f1. Further, a resistor R1 and a switching element T1 composed of a field effect transistor are connected in parallel with the antenna formed of the resonance circuit. One end of the antenna is connected to the power supply unit 11, and the power supply unit 11 is connected to the charging capacitor C2. On the other hand, the other end of the antenna is the demodulator 12 for carrier wave.
a and the command data demodulation unit 12b,
The demodulation unit 12 a is connected to the counter 18 via the low pass filter 17. In addition, the counter 18 is SW, FET
It is connected to the control unit 19 and controls the timing of the switch SW1 and the switching element T1. The signal input from the antenna is supplied to the counter 1 in the demodulator 12a.
8 and is also connected to SW1 of the demodulation unit 12b, and the envelope detection circuit 2 via the bandpass filter 20.
1 and the counter 22. The output of the counter 22 is input to the code determination unit 23, and the code determination unit 23 determines the digital value of the command or data transmitted by the interrogator 1.

Next, the operation and output waveform of each block will be described with reference to FIG. In FIG. 2, the interrogator 1 is transmitting digital data “1” and “0”. Here, the digital data "1" and "0" are f1 and f
It is composed of two frequencies of 2 and the wave number of f1 is fixed. On the other hand, the judgment of the digital data "1" and "0" makes a difference in the wave number of f2.
Ise Number Modulation). The transponder 2 first receives the carrier wave W1 having the frequency f1 regardless of the digital data. At this time, the switching element T1 connected in parallel to the resonance circuit of the receiving unit 10 is in a non-conducting state, and the Q value of the resonance circuit is in a high state. Since the interrogator 1 transmits the carrier wave W1 having the frequency f1 which is the resonance frequency of the resonance circuit of the responder 2, the response efficiency of the responder 2 is high and the amplitude of the received waveform is sufficiently large. Power supply unit 11 connected to the receiving unit 10
Then, the signal from the interrogator 1 is rectified and converted into direct current, and the charging capacitor C2 is charged. The power source charged by the capacitor C2 is used as a power source for the IC of the responder 2. A full-wave rectifier circuit or a half-wave rectifier circuit can be considered as the rectifier circuit in the power supply unit.

While the carrier wave W1 is charged in the charging capacitor C2, it is input to the counter 18 via the low-pass filter 17 in the demodulator 12a. Counter 18 here
Then, the wave number of the carrier wave is counted. When the set wave number is input, the output of the counter 18 is switched from "H" to "L". The output of the counter 18 is S
W, is transmitted to the FET control unit, and the timing of conduction of the switching element T1 is set. Switching element T
1 becomes conductive, so that the coil L1 and the capacitor C
The resistor R1 is connected in parallel to the resonance circuit of 1 and the Q value of the resonance circuit becomes low. Since the Q value of the resonance circuit is lowered, the influence of the vibration energy remaining in the resonance circuit is removed.

On the other hand, the output of the SW / FET controller 19 is also connected to the switch SW1 to control the on / off of the switch SW1. Here, the switch SW1 is turned on while the switching element T1 is conducting, and the demodulation unit 12b
The received signal is transmitted to. Here, the frequency of the carrier wave transmitted by the interrogator 1 is switched from f1 to f2.
The frequency f2 is a frequency higher than f1, and a frequency that is several times to several tens of times f1 is used. The interrogator 1 performs PNM pulse modulation by the carrier wave W2 having the frequency f2 to distinguish between digital data "1" and "0". In FIG. 2, the wave number of the carrier wave is set to 70% when the digital data is "1" and 30% when the time is "0", with the time for forming one bit being 100%. Since SW1 is turned on in the responder 2, the signal received by the receiving unit is input to the counter 22 and the envelope detection circuit via the filter. The filter is a bandpass filter 20.
Is used to extract the frequency f2. The counter 22 counts the number of carrier waves when the envelope detection output is "H". Here, since the Q value of the resonance circuit is low, there is no residual vibration energy, so that it is possible to count only the wave number substantially the same as the wave number of the carrier wave W2 transmitted by the interrogator 1. The wave numbers S0 and S1 counted by the counter 22 are converted into digital data by the code determination unit 23. When the carrier wave from the interrogator 1 is stopped, the envelope detection output becomes "L", and the SW and the FET controller 19 outputs S
W1 is turned off, and signal transmission to the demodulation unit 12b is stopped. On the other hand, since the power supply voltage is obtained again, the switching element T1 is turned off and the Q value of the resonance circuit returns to the original high value.

By using this method, the power supply voltage of the IC can be generated for each bit by the carrier wave W1 of the frequency f1, and the transmitted digital data is the wave number of the PNM made by the carrier wave W2 of the frequency f2 higher than f1. S0,
It can be obtained by analyzing S1, and since the Q value of the resonant circuit is set to be low when receiving data, it is not affected by the vibration energy remaining in the resonant circuit, and even at a high bit rate. PNM sent by the interrogator 1
It is possible to accurately receive the wave number of.

Next, an application example of the transmission / reception method shown in FIG. 2 will be described. FIG. 3 is an application example of the transmission / reception method shown in FIG. As the demodulation method of the transponder 2, the above-mentioned method is used. However, the interrogator 1 transmits a plurality of bits of data after transmitting the carrier wave W1 of the frequency f1 for power transmission. The responder 2 counts the carrier wave W1, and when the set number of counts is reached, the switching element T1 is turned on and the Q value of the resonance circuit is reduced. The time during which the switching element T1 is turned on is during the time when the data is continuously transmitted by the preset number of bits. Since the Q value of the resonance circuit is lowered while the switching element T1 is conducting,
Since the received waveform amplitude decreases, it is almost impossible to obtain electric power, and the power consumed in the demodulation unit 12 further decreases the power supply voltage charged in the charging capacitor C2. Therefore, when receiving data, the IC of the transponder 2
The carrier wave W for power supply transmitted by the interrogator 1 is set so as not to fall below the threshold of the power supply voltage at which the interrogator can operate.
It is necessary to set the wave number of 1, the number of data bits of continuous data transmission, and the capacitance value of the charging capacitor C2. By increasing the capacitance value of the charging capacitor C2,
It is possible to increase the number of bits of data to be continuously transmitted, but the charging time with the carrier wave W1 for power supply becomes long. On the other hand, if the capacitance value of the charging capacitor C2 is reduced, the charging period is shortened, but the number of bits of data that can be transmitted is reduced. These values are set according to the applications used by the interrogator 1 and the responder 2.

Embodiment 2 FIG. FIG. 4 shows a second embodiment of the non-contact data transmitting / receiving method and the apparatus thereof in the present invention, and is a waveform diagram showing a method of correcting the count number of carrier waves for power transmission. Here, when the Q value of the resonance circuit is set to be high in order to efficiently supply electric power, there is a difference in the waveform received by the resonance circuit of the responder 2 due to the difference in the communication distance between the interrogator 1 and the responder 2. An embodiment for solving the problem that occurs is shown in FIG. In FIG. 4, the responder 2a is located near the interrogator 1, while the responder 2b is located within the communication area 3 but is far from the interrogator 1. Looking at the received waveform of the responder 2b, since the Q value of the resonance circuit is set high and the communication distance with the interrogator 1 is long, the carrier wave for power supply transmitted by the interrogator 1 is Regarding W1, a phenomenon occurs in which the rising edge of the waveform in the resonance circuit of the transponder 2 is delayed. As a result, when the number of waves counted by the counter 18 is fixed, the output timing of the counter 18 differs depending on the communication distance between the interrogator 1 and the responder 2, and the timing for lowering the Q value of the resonance circuit is the responder. The problem arises that it is different for each.

Therefore, a method of setting the count value counted by the counter 18 for each responder will be described below. In FIG. 4, the interrogator 1 transmits a start text STX for notifying each responder of the start of communication at the beginning of communication. The STX is an unmodulated wave having a set wave number of the frequency f1, but the wave number is set to be larger than that of the unmodulated wave W1 for power supply thereafter so as to prevent both from being erroneously recognized. Each responder counts the number of STX waves received by the counter A. The interrogator 1 creates a transmission stop state G1 for a certain period after STX transmission, and stops transmission of the carrier wave. Each responder detects this carrier wave stop state and stores the count number of the counter A until then. Here, as described above, the wave number of the STX received by each responder is different due to the difference in communication distance. In the example of FIG. 4, the interrogator 1 transmits STX composed of 30 unmodulated waves, but in the responder 2a, the carrier wave received by the resonant circuit rises quickly, but the effect of residual vibration energy Therefore, STX is determined to be 32 waves. On the other hand, in the transponder 2b, the influence of the remaining vibration energy occurs similarly to the transponder 2a, but since the communication distance is long, the rise of the waveform received by the resonance circuit is slow and the number of waves counted by the counter 18 is 28. It is a wave. Here, in each transponder, the interrogator 1 is 30 as STX.
Since the transponder 2a has previously recognized that the unmodulated wave of the wave has been transmitted, the responder 2a has obtained the count value of 30 waves or more, which is the set value. Each block of the demodulation unit is set so that the Q value of the resonance circuit is lowered at the time when the same wave number as the wave number is counted to receive the command by the modulated wave of the PNM.

On the other hand, the responder 2b grasps that the communication distance is far from the fact that the interrogator 1 received only 28 carrier waves transmitted as STX, and thereafter the number of counts of the carrier W1 for power supply is counted. Are changed as shown in FIG.
That is, when the interrogator 1 transmits a carrier wave W1 of 20 waves, the counter 1 is equal to the number of waves minus the number of waves Nx.
Count at 8. Nx is calculated from the difference between the wave numbers generated when STX is received, and in the example of FIG.
Since only 28 waves could be received for X, the effect of vibration energy remaining in the resonant circuit was taken into consideration and Nx
Is set as 4 waves. Therefore, the number of carrier waves for power supply counted by the transponder 2b is set to 16 waves. As a result, the responder 2a and the responder 2B can set the state where the command from the interrogator 1 is received by making the switching element T1 conductive at the same timing to lower the Q value of the resonance circuit.
In order to ensure the correction of Nx, the interrogator 1 creates a short transmission stop state after transmitting the carrier wave W1 for power transmission, and each responder surely lowers the Q value of the resonance circuit before the command. It is also conceivable to set the PNM so that it can be received.

In this method, each responder grasps the reception state when the Q value of the resonant circuit is high based on the wave number received by the STX transmitted by the interrogator 1, and lowers the Q value of the resonant circuit in the subsequent communication. Since the timing is corrected by itself, it is possible to eliminate the problem that the reception state in the resonance circuit differs due to the difference in communication distance and the timing for setting the command reception state differs depending on each responder. .

[0025]

The command or data transmitted by the interrogator is received by the responder existing in the communication area, and the data stored in the memory is read according to the command,
Or, in the transponder system that writes data and sends the data in the memory to the interrogator, the interrogator alternately transmits the carrier wave for power transmission and the carrier wave for data transmission such as command, and at the time of data transmission. Is set higher than the frequency for power transmission, on the other hand, the transponder sets the Q value of the resonance circuit high when receiving the carrier wave for power transmission, and sets the Q value of the resonance circuit when receiving data. Since the setting is made low, high-speed communication is possible and the communication time can be shortened. In addition, each responder grasps the reception state when the Q value of the resonance circuit is high by the start text transmitted from the interrogator, and sets the timing for lowering the Q value of the resonance circuit to receive data. Therefore, it is possible to correct the difference in the rising of the received waveform of the resonance circuit due to the difference in the communication distance between the interrogator and each responder, and each responder can create a good communication state at the same timing.

According to the first aspect of the invention, the carrier for power supply and the carrier for command data are alternately transmitted from the interrogator, and the carrier for power supply has a constant frequency. For each bit, the power supply voltage on the responder side can be generated from the carrier for power supply from the interrogator, and the responder receives the carrier for power supply by raising the Q value of the resonant circuit of the responder. With this configuration, even if the power supply voltage of the transponder drops during communication, it is possible to keep the charging voltage of the charging capacitor at or above the power supply voltage value at which the transponder can operate. It is not necessary to incorporate electric parts such as, and it is possible to transmit a large amount of data. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Since it is set to be low, it is not affected by the vibration energy remaining in the resonance circuit, and it is possible to accurately receive the wave number of the transmitted wave transmitted by the interrogator even at a high bit rate, and to communicate. This has the effect of shortening the time.

According to the second aspect of the present invention, in the first aspect, the value of the command data is displayed according to the wave number of the carrier wave for the command data. Therefore, the identification of the signal on the responder side is extremely easy. As in claim 1, the power supply voltage on the responder side can be generated by the carrier wave for power supply from the interrogator for each command data, and the responder can resonate the carrier wave for power supply. Since the Q value of the circuit is raised for reception, even if the power supply voltage of the transponder drops during communication, the charging voltage of the charging capacitor must be kept above the power supply voltage value at which the transponder can operate. This makes it possible to transmit a large amount of data without the need for a built-in electric component such as a battery on the side of the responder. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Since it is set to be low, it is not affected by the vibration energy remaining in the resonance circuit, and it is possible to accurately receive the wave number of the transmitted wave transmitted by the interrogator even at a high bit rate, and to communicate. This has the effect of shortening the time.

According to the third aspect of the present invention, in the second aspect, one bit is displayed by a set of a carrier wave for power supply and a carrier wave for command data. Therefore, when receiving command data, The power on the responder side can be secured, and similarly to claim 1, the power supply voltage on the responder side can be generated by the carrier wave for power supply from the interrogator for each command data, and the responder carrier wave for power supply. Is received by raising the Q value of the resonance circuit of the transponder. Therefore, even if the power supply voltage of the transponder drops during communication, the charging voltage of the charging capacitor is the operating power supply of the transponder. It is possible to maintain the voltage value or more, and it is not necessary to incorporate electric parts such as a battery into the responder side, and a large amount of data can be transmitted. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Is set so that
It is possible to accurately receive the wave number of the transmission wave transmitted by the interrogator even at a high bit rate without being affected by the vibration energy remaining in the resonance circuit, and to shorten the communication time.

According to the invention described in claim 4, in claim 2, since the carrier wave for power supply is transmitted and then the carrier wave for command data is transmitted by a plurality of bits, the responder side Receiving command data is extremely efficient and reduces communication time. Similarly to the first aspect, the power supply voltage on the responder side can be generated for each command data by the carrier wave for power supply from the interrogator, and the responder can generate the carrier wave for power supply by the Q of the resonance circuit of the responder. Since the value is raised and received, even if the power supply voltage of the transponder drops during communication, it becomes possible to keep the charging voltage of the charging capacitor above the power supply voltage value at which the transponder can operate. , It is not necessary to incorporate an electric component such as a battery in the response device side, and a large amount of data can be transmitted. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Since it is set to be low, it is not affected by the vibration energy remaining in the resonance circuit, and it is possible to accurately receive the wave number of the transmitted wave transmitted by the interrogator even at a high bit rate, and to communicate. This has the effect of shortening the time.

According to the invention described in claim 5, at the start of communication, the interrogator transmits a start text having a predetermined wave number, stops transmission for a predetermined time, and then transmits a carrier wave for power supply. , And then transmits the carrier wave for command data, while the responder receives the start text from the interrogator, compares the wave number of the received start text with the wave number of the start text transmitted by the interrogator, and The distance from the interrogator is grasped from the difference, and the wave number of the carrier wave for electric power transmission to be received is corrected according to the difference in the wave number. Regardless of whether it is early or late, all responders can reduce the Q value of the resonance circuit at the same timing to form a command data reception form. In addition, the interrogator alternately transmits a carrier wave for power supply and a carrier wave for command data, and the carrier wave for power supply has a constant frequency and is composed of a predetermined wave number, and the carrier wave for command data is The transponder has a frequency of a predetermined ratio to the carrier wave for power supply, the transponder receives the carrier wave for power supply by increasing the Q value of the resonance circuit of the transponder, and receives the carrier wave for command data of the transponder. Since the Q value of the resonance circuit is lowered and received, the power supply voltage on the responder side can be generated by the carrier wave for power supply from the interrogator for each command data, and the responder responds with the carrier wave for power supply. Since the Q value of the resonance circuit of the device is raised and received,
Even if the power supply voltage of the transponder drops during communication, it is possible to keep the charging voltage of the charging capacitor at or above the power supply voltage value at which the transponder can operate. A large amount of data can be transmitted without the need to incorporate it. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Since it is set to be low, it is not affected by the vibration energy remaining in the resonance circuit, and it is possible to accurately receive the wave number of the transmitted wave transmitted by the interrogator even at a high bit rate, and to communicate. This has the effect of shortening the time.

According to the sixth aspect of the invention, the interrogator comprises:
Transmitting means for alternately transmitting a carrier wave for power supply having a constant frequency and a predetermined wave number, and a carrier wave in which command data having a frequency of a predetermined multiplication factor with respect to the carrier wave for power supply is modulated by ASK And a transponder for transmitting and receiving a signal to and from the interrogator, and a carrier wave for power supply from the interrogator, which is configured by a parallel resonance circuit of a coil and a capacitor, is converted into direct current, and The internal power supply means that uses the DC power as the internal power supply of the responder, the carrier demodulator for power that counts the wave number of the carrier wave for power supply, and the envelope of the carrier wave for command data are detected. The resonance frequency of the parallel resonance circuit is reduced by the output of the command data demodulator that demodulates the command data and the power carrier demodulator and command data demodulator. Since a series circuit consisting of a resistor and a switch is provided, the power supply voltage on the responder side can be generated by the carrier wave of the transmission frequency from the interrogator for each command data, and the responder uses the carrier wave for power supply. Since the Q value of the resonance circuit of the transponder is raised and received, even if the power supply voltage of the transponder drops during communication, the charging voltage of the charging capacitor is the power supply voltage value at which the transponder can operate. It becomes possible to keep the above, and it is not necessary to incorporate electric parts such as a battery into the responder side, and a large amount of data can be transmitted. Also, the digital data transmitted to the responder can be obtained by analyzing the wave number created by the carrier having a frequency higher than the transmission frequency from the interrogator. Furthermore, the Q value of the resonance circuit at the time of data reception in the responder. Is set so that
It is possible to accurately receive the wave number of the transmission wave transmitted by the interrogator even at a high bit rate without being affected by the vibration energy remaining in the resonance circuit, and to shorten the communication time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transponder of a non-contact data transmitting / receiving apparatus which realizes a non-contact data transmitting / receiving method according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing communication waveforms of an interrogator and a responder in the non-contact data transmission / reception method and device according to the present invention.

FIG. 3 is a communication waveform diagram of an interrogator and a responder showing another embodiment of the non-contact data transmission / reception method and device according to the present invention.

FIG. 4 is a waveform diagram showing a second mode of the non-contact data transmitting / receiving method and the apparatus thereof in the present invention, showing a method of correcting the count number of carrier waves for power transmission.

FIG. 5 is a block diagram showing a circuit configuration of a conventional non-contact data transmission / reception device.

FIG. 6 is a timing chart showing a demodulation impossible state in the ASK method of the conventional non-contact data transmitting / receiving apparatus.

[Explanation of symbols]

 1 Interrogator 2 Responder 3 Communication Area 6 Transmitter 7 Receiver 10 Receiver 11 Power Supply 16 Receiver 12a Carrier Wave Demodulator 12b Command Data Demodulator R1 Resistor T1 Switching Element

Claims (6)

[Claims] 1. A command and data are transmitted from an interrogator to a responder in an ASK method in a communication area,
In the contactless data transmission / reception method in which the responder accesses the internal memory for this command, and transmits the response data from the responder to the interrogator,
A carrier for power supply and a carrier for command data are alternately transmitted from the interrogator, and the carrier for power supply has a constant frequency and is composed of a predetermined wave number. The carrier wave has a frequency of a predetermined multiplication factor with respect to the carrier wave for power supply, and the responder receives the carrier wave for power supply by increasing the Q value of the resonance circuit of the responder and receives the command data. The non-contact data transmission / reception method characterized in that the carrier wave is received by lowering the Q value of the resonance circuit of the transponder. 2. The non-contact data transmission / reception method according to claim 1, wherein the digital value of the command data is determined by the wave number of the carrier wave for the command data. 3. The combination according to claim 2, wherein a set of the carrier wave for power supply and the carrier wave for command data is used.
A non-contact data transmission / reception method characterized by comprising bits. 4. The non-contact data transmission / reception method according to claim 2, wherein after transmitting the power supply carrier wave, the command data carrier wave is transmitted by a plurality of bits. 5. A command or data is transmitted from an interrogator to a responder in an ASK method in a communication area,
In the contactless data transmission / reception method in which the responder accesses the internal memory for this command, and transmits the response data from the responder to the interrogator,
A carrier for power supply and a carrier for command data are alternately transmitted from the interrogator, and the carrier for power supply has a constant frequency and is composed of a predetermined wave number. The carrier wave has a frequency of a predetermined multiplication factor with respect to the power supply carrier wave, and the transponder receives the power supply carrier wave by raising the Q value of the resonance circuit of the transponder and receives the command data. The carrier wave is received by lowering the Q value of the resonance circuit of the transponder, and at the start of communication, the interrogator transmits a start text of a predetermined wave number, then stops transmission for a predetermined time, and then supplies power. For the command data, while the responder receives the start text from the interrogator and gives the wave number of the received start text. For comparison with the wave number of the start text transmitted by the interrogator set for this purpose, the distance to the interrogator is grasped from the difference in the wave number, and the carrier wave for power transmission received according to the wave number difference is received. A non-contact data transmission / reception method characterized by correcting the wave number. 6. An interrogator transmits a command or data to a responder in a communication area, and the responder accesses an internal memory for the command, and
In the non-contact data transmission / reception apparatus of the ASK system for transmitting response data from the transponder to the interrogator, the interrogator has a constant frequency and a carrier wave for power supply having a predetermined wave number, Transmitting means for alternately transmitting a carrier wave modulated by the ASK method for command data having a frequency of a predetermined magnification with respect to the carrier wave for power supply is provided, and the responder has a parallel resonance circuit of a coil and a capacitor. And an internal power source that converts the carrier wave for power supply from the interrogator into direct current and uses the direct current power as the internal power source of the responder. Means, a power carrier demodulation unit for counting the number of waves of the power supply carrier, and an envelope of the command data carrier are detected. It also comprises a command data demodulation unit for demodulating command data from the interrogator, a resistor and a switch for lowering the Q value of the parallel resonant circuit by the outputs of the power carrier demodulation unit and the command data demodulation unit. A non-contact data transmission / reception device comprising a series circuit.