JPH09298485A - Contactless data transmission reception method and its equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain transmission of digital data accurately from an interrogator to a responder and a drive power supply for the responder with a comparatively simple configuration by providing a control section, a modulation section and a transmission means to the interrogator and providing a demodulation section to the responder. SOLUTION: An interrogator 1 uses a transmission section 6, that is, a series resonance circuit having an antenna function to send a high frequency signal to a responder 2 in existence in a communication area 3. The series resonance circuit being a component of the transmission section 6 of the interrogator 1 is a circuit to send power efficiently to the responder 2. The high frequency signal is obtained by using a modulator 5 to modulate a signal from an oscillator 4 based on a digital command transmitted from a control part 9 for the responder 2. For example, as commands, specific ID codes stored in a memory 14 in the responder 2 and various data are read and returned or data are written in the memory 14 contactless.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production line, a distribution line of a factory, an entrance / exit management of an office, etc., in which an ID card is attached to a tool or a luggage, or a person is provided with a non-contact data responder for non-contact. It relates to a method and device for communicating and managing data with, and registers a unique ID code, product number, manufacturing data, etc. in the responder, and identifies the responder by communicating the data in a contactless manner. And a device therefor.

[0002]

2. Description of the Related Art FIG. 9 shows a contactless data communication device.
Schematic diagram showing the general usage of the interrogator and transponder, Fig. 1
0 is a block diagram showing a configuration of a conventional non-contact data communication device, and FIG. 11 is a waveform diagram showing an interrogator of the conventional non-contact data communication device and a communication waveform in a transmitting / receiving state of the interrogator. In FIG. 9, 1 is an interrogator, and 2 is a responder that communicates with the interrogator 1 in the communication area 3. See also FIG.
At 0, the interrogator 1 is composed of an oscillator 4, a modulator 5, a transmitter 6, a receiver 7, a demodulator 8 and a controller 9. Further, 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. Cb is a capacitor connected to the power supply circuit and is used as the power supply of the responder 2.

Next, the operation of the conventional non-contact data transmitting / receiving apparatus will be described. Generally, in this type of non-contact identification system, a usage state as shown in FIG. 9 is adopted. That is, when the responder 2 is in the communication area 3, the interrogator 1 communicates with the responder 2. At this time, the interrogator 1 and the responder 2 in the conventional non-contact data transmitter / receiver have the configuration shown in FIG. 10, and the interrogator 1 reads the data in the memory built in the responder 2 with respect to the responder 2. , Or write command and write data are ASK-modulated and transmitted. At this time, on the interrogator 1 side, the transponder 2 discriminates between the digital values “0” and “1” as shown in FIG.
According to the digital data shown in FIG.
As shown in (b), the pulse number modulation (PNM: Pulse Number Module) that changes the number of carrier waves is performed.
transmission). This figure shows that assuming that the time for transmitting 20 carrier waves is 1 bit transmission time, 6 waves (30%) are used for "0" and 14 waves (70%) are used for "1" within that time. In this example, the transmission stop periods Ga and Gb for stopping the transmission are provided after the carrier wave to notify the end of the 1-bit data. In general, the transponder 2 has a resonance circuit with a high Q value mounted in the receiving section in order to receive electric power as well as data.
The carrier wave from the interrogator 1 is received by this resonant circuit. The transponder 2 receives the internal LS from the carrier transmitted from the interrogator 1.
In addition to obtaining the drive power of I, the command and data and the clock for operating the internal LSI are extracted by the envelope detection.

However, when the carrier wave from the interrogator 1 is received by the resonant circuit having a high Q value mounted on the transponder 2,
The received waveform is as shown in FIG. The interrogator 1 created the transmission stop periods Ga and Gb shown in FIG. 11 in order to notify the end of the 1-bit data, but vibration energy remains in the resonance circuit of the transponder 2 and is slowly attenuated. Since the transponder 2 determines the digital data transmitted from the interrogator 1 based on the wave number received during the transmission stop period Ga to Gb, the digital data “0” having a small wave number is retained due to the residual vibration energy. There is a possibility that "" may be erroneously determined as "1" having a large number of waves. Also, the envelope detection output is compared with the threshold voltage Vref in the comparator, and the period when the output of the comparator is “L” is determined to be the transmission stop period Ga or Gb. When it is "1", the envelope detection output does not become Vref or less and the transmission stop period Ga cannot be detected, so that there is a problem that demodulation becomes impossible. In order to solve this problem, the interrogator 1 needs to lengthen the transmission stop periods Ga and Gb. However, if the transmission stop periods Ga and Gb are set long, the communication speed of the digital data to be transmitted is reduced, and high-speed communication becomes impossible. On the other hand, if the Q value of the resonance circuit is lowered, the residual vibration will converge quickly, but
Since the SI drive power is generated from the data signal from the interrogator 1, the energy received is weakened by lowering the Q value, the drive power cannot be taken in efficiently, and the communication distance is shortened. There was a problem.

On the other hand, the interrogator 1 is FSK (Frequent).
cy Shift Keying and PSK (Phas)
The signal is transmitted by another modulation method such as e Shift Keying, and the transponder 2 uses a PLL (Phase Locke).
Although a method of demodulating using d Loop) or the like can be considered, there is a problem that the demodulation circuit becomes complicated. Further, in the demodulation method of comparing phases using a multiplier or the like, it is necessary to mount a precise internal standard clock on the transponder 2. IC
An oscillator such as a ring oscillator is conceivable as the one that creates the clock inside, but the oscillation frequency varies greatly depending on each responder 2 due to variations in power supply voltage, ambient temperature, and manufacturing, and when demodulating using this oscillator There is a problem that all the transponders 2 cannot normally demodulate the data.

[0006]

As described above, the problem to be solved by the present invention is that even if the interrogator makes a transmission stop period to signal the end of the data, the vibration energy causes the interrogator to leave the transmission stop period. The transmitted digital data cannot be demodulated accurately, and conversely, the transmission stop period is long and high-speed communication becomes impossible. Further, if the Q value of the resonance circuit is lowered, it is difficult to secure the driving power source and the communication distance becomes short. In a method of communicating with another modulation method, a demodulation circuit becomes complicated, and in a demodulation method of comparing phases using a multiplier or the like, it is necessary to mount a precise internal standard clock in a responder. Even if an oscillator such as a ring oscillator is used to generate a clock in an IC, not all transponders can normally demodulate data.

The present invention has been made in order to solve the above problems, and has a relatively simple structure and accurately transmits digital data from an interrogator to a responder and secures a driving power supply in the responder. The purpose is.

[0008]

According to a first aspect of the present invention, there is provided a contactless data transmission / reception method, wherein an interrogator sends a response device a phase of a carrier wave every time digital data constituting command data or the like changes. The responder responds to the interrogator by abrupt change in amplitude, which occurs when the carrier wave received from the interrogator received by the resonant circuit is inverted in phase and the vibration energy remaining in the resonant circuit overlaps. It detects that the digital value of the command data from is changed.

In the non-contact data transmission / reception method according to the second aspect of the present invention, the interrogator inverts the phase of the carrier wave by 180 ° for each bit of the digital data forming the command data and the phase of the carrier wave. After inversion, the wave number of the carrier until the next phase inversion is transmitted by changing it according to digital data, and the responder remains in the carrier and the phase-inverted carrier from the interrogator received by the resonant circuit. Detects the start or end of one bit of the digital value by the sharp change in amplitude that occurs due to the overlap of vibration energy, and asks from the wave number of the carrier wave from the change in amplitude to the occurrence of the next change in amplitude. The digital data transmitted by the container is determined.

A contactless data transmission / reception method according to a third aspect of the present invention is the method according to the first or second aspect, wherein the transponder uses the carrier wave extracted from one end of the resonant circuit to perform amplitude detection by envelope detection. Of the carrier wave from the interrogator is detected.

A contactless data transmission / reception method according to a fourth aspect of the present invention is the method according to the first or second aspect, wherein the responder inputs the carrier wave extracted from one end of the resonance circuit to the first inverter, and The carrier extracted from the other end of the resonance circuit is input to the second inverter, the outputs of the first and second inverters are ORed, and the output is filtered to obtain the carrier from the interrogator. It detects a change in phase.

A contactless data transmission / reception method according to a fifth aspect of the present invention is the method according to the first or second aspect, wherein the transponder inputs the carrier wave extracted from one end of the resonance circuit to the first inverter, and The carrier extracted from the same end of the resonance circuit is input to the second inverter, and the output and the input of the second inverter are fed back by a resistor to obtain the exclusive OR of the outputs of the first and second inverters. Then, the change in the phase of the carrier wave from the interrogator is detected from the signal whose output is filtered.

In the non-contact data transmitting / receiving apparatus according to the sixth aspect of the present invention, the phase of the carrier wave is 180 ° whenever the digital data forming the command data or the like changes in the interrogator.
A control unit that generates an inverted code, a modulation unit that performs modulation according to the code generated by the control unit, a transmission unit that transmits the carrier wave modulated by the modulation unit, and an interrogator for the responder. The digital value of the command data changes due to the sharp change in amplitude that occurs when the carrier wave whose phase is inverted from the interrogator received by the resonance circuit that receives the digital signal transmitted from A demodulation unit for detecting the change is provided.

In the non-contact data transmitter / receiver according to the seventh aspect of the present invention, the interrogator causes the interrogator to set the phase of the carrier wave to 180 ° for each bit of the digital data constituting the command data or the like.
After reversing and reversing the phase of the carrier wave, the control unit that generates a code that makes the wave number of the carrier wave until the next phase is reversed depends on the digital value, and the code generated by this control unit. Therefore, a modulator for performing modulation and a transmitter for transmitting the carrier modulated by the modulator are provided, and the responder has a receiver for receiving the inverted carrier from the interrogator and a receiver for receiving the inverted carrier. Waveform shaping circuit for waveform shaping a carrier wave and a phase inversion detection circuit for detecting the start or end of one bit of digital data due to a sharp change in amplitude caused by the overlapping of vibration energy remaining in the carrier wave and the resonance circuit. And a clock generation circuit that generates a clock from the outputs of the phase inversion detection circuit and the waveform shaping circuit, and the clock generation circuit and the phase inversion detection circuit. A counter that counts the number of waves of a digital value from the output of the circuit, a data determination unit that determines the digital value from the output of this counter, and a control unit that controls the access to the memory by the output of the data determination unit are provided. It is a thing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1. FIG. 1 is a block diagram showing a configuration of an interrogator 1 and 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. FIG. 2 shows an interrogator and a responder. It is a figure which shows a transmission / reception waveform. In the configuration shown in FIG. 1, description of the same or similar portions as those in the block diagram shown in FIG. 10 will be omitted. FIG.
10, a more detailed point is that the receiving unit and the transmitting unit of the transponder 2 shown in FIG.
In the interrogator 1, the transmitting unit 6 of FIG. 10 is composed of a capacitor C6 and a resistor R.
6 and the coil L6 in series, and the receiving section is represented by a parallel resonant circuit of the coil L7 and the capacitor C7, and the rectifying circuit 17 is provided between the transmitting / receiving section 10 and the power supply section 11. .

Next, the operation in FIG. 1 will be described.
That is, in FIG. 1, the interrogator 1 emits a high-frequency signal to the transponder 2 existing in the communication area 3 by the transmitting unit 6, that is, the series resonance circuit having an antenna function. The series resonance circuit that constitutes the transmitter 6 of the interrogator 1 is the responder 2
This is for efficiently transmitting power to the device. The high frequency signal is obtained by modulating the signal from the oscillator 4 by the modulator 5 in response to a digital value command transmitted from the controller 9 to the responder 2. The command is, for example, a command for reading and returning a unique ID code or various data stored in the memory 14 in the transponder 2, a command for writing data in the memory 14 in a non-contact manner, or the like. Here, the interrogator 1 causes the modulator 5 to generate a PSK transmission signal as shown in FIG. PSK uses a method of changing the phase according to the digital value from the control unit 9. In FIG. 2, the digital value is "0" to "1" or "1" to "0".
The phase is inverted by 180 ° when changing to.

On the other hand, the responder 2 receives the signal from the interrogator 1 by the parallel resonance circuit including the coil L10 and the capacitor C10. The high frequency signal from the interrogator 1 is transmitted to the rectification circuit 17 and the demodulation unit 12 connected to the resonance circuit, rectified in the rectification circuit 17, and charged in the external charging capacitor Cb through the power supply unit 11. The power source charged by the external charging capacitor Cb is used by the power source unit 11 as a power source for the internal circuit (LSI) of the responder 2. Transponder 2
In order to obtain a sufficient power supply, the resonance circuit of the transponder 2 has a high Q value so that a high frequency signal can be efficiently received. As the rectifier circuit 17, a full-wave rectifier circuit, a half-wave rectifier circuit, or the like is used. The resonance circuit is also connected to the demodulation unit 12 to demodulate the modulated carrier wave from the interrogator 1.
The digital data demodulated by the demodulation unit 12 is transmitted to the control unit 13. In accordance with the command transmitted from the interrogator 1, the control unit 13 performs processing such as reading data from the memory 14 or writing data transmitted following the command. Since the transponder 2 receives the internal power supply from the carrier wave from the interrogator 1, the memory 14 uses a non-volatile memory such as an EEPROM.

In FIG. 1, it is conceivable to integrate the components other than the resonance circuit and the charging capacitor into one chip with an LSI to reduce the size of the transponder 2 and reduce the cost. The controller 13 transmits the data read from the memory 14 to the modulator 15,
The modulator 15 modulates according to the data, and the resonant circuit, that is, the transmitter / receiver 10 returns the data. In FIG. 1, one resonance circuit performs reception and transmission, but a resonance circuit for reception and a resonance circuit for transmission, or an antenna may be mounted separately.

Next, the case where the interrogator 1 changes the digital value from the control unit 13 and inverts the phase by 180 ° in PSK will be described. In FIG. 2, the resonance circuit of the transponder 2 vibrates at a constant phase at X before the phase is switched. When the phase of the carrier wave from the interrogator 1 is inverted by 180 ° due to the change in the digital value, the resonant circuit of the transponder 2 tries to excite the vibration energy of the phase Y opposite to that at the time of X. To do. Therefore, in Z between X and Y, the residual of the vibration energy of X and the excitation of the vibration energy of the new antiphase of Y are overlapped and vibrate with the sum of the vibration energy of each other. Phase is 180 between X and Y
Since they are different from each other, they cancel each other out in the Z section, the vibration of the resonance circuit is attenuated, and the amplitude is reduced. At this time, as compared with the case where only the vibration energy remains as in ASK, the attenuation of the amplitude is steep because the vibration energy of the inverted phase is canceled. The transponder 2 transmits this signal to the demodulation unit 12. The demodulation unit 12 performs envelope detection of the signal from the resonance circuit using the envelope detection circuit as shown in FIG. 3, for example.

FIG. 3 is a circuit diagram showing an envelope detection circuit. The envelope detection circuit shown in FIG. 3 outputs the output from the resonance circuit to resistors R11 and R12 and capacitors C11 and C12.
The inverting circuit 2 configured to be connected to the comparison terminal of the comparator 19 via the smoothing circuit composed of and to be compared with the threshold voltage Vref supplied to the reference voltage terminal of the comparator 19.
Although it is supplied to the code determination logic 21 through 0, the envelope detection circuit 18 thereof is well known, and the detailed description thereof will be omitted.

Next, the operation of the demodulation section using the envelope detection circuit shown in FIG. 3 will be described. Envelope detection circuit 1
The output of 8 is compared with the threshold voltage Vref by the comparator 19, and the sign determination logic 21 detects that the voltage has become equal to or lower than Vref and transmits it to the control unit 13. Control unit 1
In No. 3, if it is determined that the phase has not changed for a certain period of time, it is determined that it is the same as the previous digital value, and if the output of the demodulation unit 12 has changed, it is determined that the previous digital value is inverted. The fixed period is the time during which the interrogator 1 transmits 1 bit of digital data, and the transponder 2 may judge from the wave number of the carrier wave. Also, an oscillator is mounted inside the transponder 2 to measure the fixed period. Good. The interrogator 1 first transmits a start signal of certain digital data in order to notify the responder 2 of the start of communication, and the responder 2 judges the same data or inverted data with reference to the signal and makes an inquiry. It is determined whether the digital value such as the command transmitted from the device 1 or the write data to the memory 14 is "0" or "1".

On the other hand, as another configuration example of the demodulation section 12, FIG.
A circuit like is also conceivable. 4 is a circuit diagram showing another configuration example of the demodulation section, and FIG. 5 is a waveform diagram showing the waveform of each section in FIG. is there. In FIG. 4, C13 and C14 are capacitors, 22 is a first inverter, 23 is a second inverter, 24 is a disjunction circuit,
R13 is a resistor, C15 is a capacitor, and 25 and 26 are inverting circuits.

The operation of FIG. 4 will be described with reference to FIG. That is, both ends of the resonance circuit are input to the inverters 22 and 23 via the capacitors C13 and C14, respectively. The inverters 22 and 23 have a hysteresis to prevent malfunction due to disturbance transmitted from the resonance circuit. In this case, the inverters 22 and 23 are
When the received amplitude voltage is less than the threshold voltage of,
The output of each inverter remains "L", and the phases of both ends of the resonant circuit are different by 180 °, so that the outputs of the respective inverters are as shown in b and c of FIG. Therefore, the logical disjunction circuit 24 takes the logical disjunction d of these two outputs. Since a short pulse appears at this output d, this output is passed through a filter composed of a resistor R13 and a capacitor C15, and the amplitude is changed. The output e only when attenuated is extracted. It is determined from the waveform-shaped output f that the phase is inverted.

FIG. 6 is a modification of FIG. In FIG. 4, a feedback resistor is connected to one inverter 22 in FIG. 4, and an exclusive OR circuit 27 is used in place of the logical OR circuit 24.
Is connected.

The operation of FIG. 6 will be described. That is, the signal taken out from one end of the resonance circuit is compared with the output of one of the inverters 22 which is fed back by the resistor and the output of which is not fed back by the exclusive OR circuit 25, and the output is filtered. A detection output like f can be obtained. Further, since it can be seen that the phase is inverted by the detection output f, the transponder 2 understands that the digital value of the command from the interrogator 1 has changed. The control section demodulates the digital data by the above-mentioned operation.

The clock used by the transponder 2 for data determination or the like may be an internal oscillator or a carrier wave from the interrogator 1. When a carrier wave is used as a clock, the threshold voltage at the time of waveform shaping for clock extraction may be lowered so that the clock can be extracted even when the amplitude is attenuated (Z in FIG. 2). The signal that can be extracted from the circuit is unstable because the waveform is distorted by the sum of X and Y in FIG. 2, and this must be taken into consideration.
Therefore, when the amplitude is attenuated, that is, when the phase inversion is confirmed in the reception waveform Z, the clock extraction from the carrier wave is stopped,
It is possible to use a method of extracting a clock only when there is no phase inversion.

Embodiment 2. FIG. 7 shows the amplitude attenuation of FIG.
That is, when the phase inversion is confirmed in the reception waveform Z, the circuit configuration showing an example in which the clock extraction from the carrier wave is stopped and the clock is extracted only when there is no phase inversion, FIG. 8 is the signal output waveform according to FIG. It is a waveform diagram showing. That is, in FIG. 7, 28 is a phase inversion detection circuit connected to the transmitting / receiving circuit 10 of the responder 2, that is, the output terminal of the parallel resonant circuit, and 29 is similarly connected to the parallel resonant circuit of the responder 2, that is, the output terminal of the transmitting / receiving circuit 10. The waveform shaping unit 30 is a clock generation unit which receives the outputs of the phase inversion detection circuit 28 and the waveform shaping unit 29, and 31 is the clock generation unit 30.
And a counter which receives the output of the phase inversion detection circuit 28, and 32, the counter 31 and the phase inversion detection circuit 2.
A data latch 33 connected to the output end of 8 and a data determination unit 33 connected to the output ends of the data latch 32 and the counter 31. The output terminal of the data determination unit 33 is connected to the control unit 13.

Next, the operation in FIG. 7 will be described.
Here, the interrogator 1 transmits with binary PSK having a phase of 0 ° and 180 °, but further, the PNM (Pulse Number) that makes the wave number of the carrier wave different according to the digital value.
r Modulation) is added. This does not only indicate that the sign is inverted on the transponder 2 side, but
This is because the digital value can be determined from the time until the wave number or the phase of the carrier wave is inverted, and the reliability of communication is improved. In FIG. 8, when the transmission wave is “1”, 20 waves, “0”
In this case, the waveform is composed of 10 waves, and the phase is inverted for each bit. When the transponder 2 receives this carrier wave, the phase inversion detection circuit 28 obtains a signal for judging the phase switching as shown in FIG. 8j. As the phase inversion detection circuit 28, a circuit as shown in FIG. 3, FIG. 4, or FIG. 6 can be considered. On the other hand, the signal k, which is extracted from one end of the resonance circuit and waveform-shaped, is input to the clock generation unit 30. The clock generation unit 30 generates a signal 1 that outputs “L” when the signal j is “H” and outputs a signal k when the signal j is “L”. The output signal 1 is output to the counter 31. Is entered. The counter 31 counts the number of pulses of the signal l from when the inversion detection signal j becomes “H” to the next “H”, and holds the count number m in the data latch 32. After that, the count value of the counter 29 is set to 0 and the input standby state of the signal 1 is set. On the other hand, when the counter 31 reaches a certain value, the data determination unit 33 determines the digital value “0” or “1” from the wave number held in the data latch 30. In FIG. 8, when the counter value becomes 3, the data determination timing signal o becomes “H”, and at the rising edge thereof, the digital value p is determined from the count number held in the data latch. In the data determination unit 33, the threshold value of the count number for determining the digital value has a certain width. In the example of FIG. 8, when the count number is 5 to 10, “0”, 1
It is set to "1" in 5 to 20. Further, the signal q generated when the counter 31 reaches the count value 5 is
Then, it is used as a clock for processing data.

Note that the clock and data determination timing of the control unit 13 may use count values other than those shown in the examples, or a plurality of timings may be created. Also, here the digital value is judged by the number of waves,
The time until the phase is inverted may be measured by a high-speed clock with an internal oscillator. Here, by modulating the digital data with the PNM, the transponder 2 can judge the digital data from the time until the wave number or the phase is inverted, and can also generate a code such as a start signal. For example, the interrogator 1 transmits a carrier wave having a wave number that can be determined as a start signal at the beginning of communication, and by counting the wave number, it transmits certain fixed digital data such as “0101” to notify the start of communication as a responder. Two
Eliminates the need to teach.

In this embodiment, the interrogator 2 transmits a carrier wave whose phase is inverted by 180 ° for each 1-bit data,
Moreover, since the PNM that changes the number of carriers until the phase is changed according to the digital data is used, the transponder 2 judges the phase switching by the sharp amplitude change of the resonance circuit, and the demodulation of the digital data changes the amplitude. It is possible to judge by the wave number of the carrier wave or the time until the phase is inverted. In addition, the amplitude change is steeper than ASK, so it is not necessary to consider the residual vibration energy, and high-speed communication with a reduced number of 1-bit carriers is possible. Can be shortened.

[0031]

According to the first aspect of the invention, the interrogator modulates the phase of the carrier wave to be transmitted by PSK which inverts by 180 ° for each change of the digital value of the command data, while the responder is the resonant circuit. Since the demodulation circuit is configured to detect the steep attenuation of the received waveform generated by the sum of the excited vibrational energy, the inversion of the digital data transmitted by the interrogator or the start and end of 1 bit of the digital data can be performed. It is possible to make a judgment, and it is possible to shorten the 1-bit period compared to ASK, which requires a sufficient period during which the interrogator does not transmit the carrier wave in consideration of the residual vibration energy. This has the effect of shortening the communication time of the transponder.

According to the second aspect of the present invention, the interrogator inverts the phase of the carrier by 180 ° for each bit of the digital data forming the command data and the interrogator inverts the phase of the carrier. , The wave number of the carrier until the next phase inversion is transmitted by changing it according to the digital data, and the responder receives the phase-inverted carrier from the interrogator received by the resonant circuit and the vibration energy remaining in the resonant circuit. The abrupt change in the amplitude causes the detection of the start or end of 1 bit of the digital value, and the interrogator transmitted from the wave number of the carrier wave from the change in the amplitude to the occurrence of the next change in the amplitude. Since the digital data is configured to be determined, the inversion of the digital data transmitted by the interrogator or the opening of one bit of the digital data is performed as in the case of claim 1. , 1 compared to ASK that must take you to determine the end, also a period in which the interrogator in consideration does not send the carrier a residual vibration energy enough
The bit period can be shortened, and the communication time between the interrogator and the responder can be shortened.

According to a third aspect of the present invention, in the first or second aspect, the transponder detects a change in amplitude by envelope detection using the carrier wave extracted from one end of the resonance circuit, Since it is configured to detect the change in the phase of the carrier wave from the interrogator, the inversion of the digital data transmitted by the interrogator or the start or end of one bit of the digital data is performed as in the case of claim 1 or 2. Can judge,
In addition, it is possible to shorten the 1-bit period compared to ASK, which requires a sufficient period in which the interrogator does not transmit the carrier wave in consideration of residual vibration energy, and the communication time between the interrogator and the responder can be shortened. There is an effect that can be shortened.

According to a fourth aspect of the present invention, in the first or second aspect, the transponder inputs the carrier wave extracted from one end of the resonance circuit to the first inverter, and the other end of the resonance circuit from the other end. The extracted carrier wave is input to the second inverter, the logical sum of the outputs of the first and second inverters is taken, and the change in the phase of the carrier wave from the interrogator is detected from the signal obtained by filtering the output. Since it was configured to
Similar to claim 1 or claim 2, it is possible to determine the inversion of the digital data transmitted by the interrogator, or the start and end of one bit of the digital data. It is possible to shorten the 1-bit period as compared with ASK, which requires a sufficient period in which no carrier wave is transmitted, and it is effective in shortening the communication time between the interrogator and the responder.

According to the fifth aspect of the present invention, in the first or second aspect, the transponder inputs the carrier wave extracted from one end of the resonance circuit to the first inverter, while the responder inputs the carrier wave from the same end of the resonance circuit. The extracted carrier wave is input to the second inverter, and the output and the input of the second inverter are fed back by a resistor, the exclusive OR of the outputs of the first and second inverters is taken, and the output is used as a filter. Since the change of the phase of the carrier wave from the interrogator is detected from the passed signal, the inversion of the digital value transmitted by the interrogator or the digital value of 1 is performed as in the case of claim 1 or claim 2.
It is possible to determine the start and end of a bit, and it is possible to shorten the 1-bit period compared to ASK, which requires a sufficient period during which the interrogator does not transmit the carrier in consideration of residual vibration energy. Therefore, there is an effect that the communication time between the interrogator and the responder can be shortened.

According to the invention of claim 6, in the interrogator,
A control unit that generates a code by inverting the phase of a carrier wave by 180 ° each time digital data that forms command data or the like changes, a modulation unit that performs modulation according to the code generated by this control unit, and the modulation unit. The transmitting means for transmitting the carrier wave modulated by the interrogator, and the responder for receiving the digital signal transmitted from the interrogator are the resonance circuit that receives the digital signal transmitted from the interrogator Since the demodulation unit for detecting the change in the digital value of the command data due to the sharp change in the amplitude caused by the overlap of energy is provided, the digital data transmitted by the interrogator as in claim 1 is provided. It is possible to determine the inversion of, or the start and end of 1 bit of digital data. Period not to transmit a wave as compared to ASK required to be taken sufficiently it is possible to shorten the period of one bit, which reduces the communication time interrogator and.

According to the invention of claim 7, in the interrogator,
If the phase of the carrier wave is inverted by 180 ° for each bit of the digital data forming the command data, and if the phase of the carrier wave is inverted and the wave number of the carrier wave until the next phase is changed depends on the digital value. A control unit that generates such a code, a modulation unit that performs modulation according to the code generated by this control unit, and a transmission unit that transmits the carrier wave modulated by the modulation unit are provided. The receiving means for receiving the inverted carrier wave from the interrogator, the waveform shaping circuit for shaping the carrier wave received by the receiving means, and the steep amplitude generated by the vibration energy remaining on the carrier wave and the resonance circuit Phase inversion detection circuit that detects the start or end of 1 bit of digital data, and this phase inversion detection circuit and waveform shaping A clock generation circuit that generates a clock from the output of the path, a counter that counts the wave number of digital data from the outputs of the clock generation circuit and the phase inversion detection circuit, and a data determination unit that determines the digital value from the output of this counter, Further, since the control section for controlling access to the memory and the like is provided by the output of the data judging section, it is possible to judge the start and end of 1 bit of the digital value, as in the second aspect. It is possible to shorten the 1-bit period compared to ASK, which requires a sufficient period during which the interrogator does not transmit the carrier wave in consideration of residual vibration energy, and shortens the communication time between the interrogator and the responder. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a responder of a contactless data transmitter / receiver for realizing a contactless data transmission / reception method according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing transmission / reception 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 circuit diagram of an envelope detection circuit in the non-contact data transmission / reception method and device according to the present invention.

FIG. 4 is a circuit diagram showing another example of the configuration of the demodulation section, showing the second mode of the non-contact data transmitting / receiving method and the apparatus thereof according to the present invention.

5 is a waveform diagram showing waveforms of respective portions in FIG.

FIG. 6 is a circuit diagram showing a second embodiment of the non-contact data transmitting / receiving method and the apparatus thereof according to the present invention, and is a circuit diagram showing another configuration example of the demodulation section as a modification of FIG.

FIG. 7 is a circuit diagram showing an example in which when phase inversion is confirmed when the amplitude of the digital data shown in FIG. 2 is attenuated, clock extraction from the carrier wave is stopped and the clock is extracted only when there is no phase inversion. .

8 is a waveform diagram showing a signal output waveform according to FIG.

FIG. 9 is a schematic diagram showing a general usage state of an interrogator and a responder in a non-contact data communication device.

FIG. 10 is a block diagram showing a configuration of a conventional non-contact data communication device.

FIG. 11 is a waveform diagram showing communication waveforms in an interrogator of a conventional non-contact data communication device and a transmission / reception state of the interrogator.

[Explanation of symbols]

 1 Interrogator 2 Responder 3 Communication Area 6 Transmitter 10 Receiver 11 Power Supply 12 Demodulator 13 Controller 14 Memory 15 Modulator 18 Envelope Detection Circuit 22 First Inverter 23 Second Inverter 24 Non-OR Circuit 27 Exclusive OR circuit R14 Resistor

Claims (7)

[Claims] 1. The interrogator transmits a carrier wave modulated with command data or the like to the responder, and the responder receives and demodulates the carrier wave by a resonance circuit, and the interrogator follows the instruction of the command or the like. In the non-contact data transmission / reception method of transmitting response data to the transmitter, the interrogator inverts the phase of the carrier wave by 180 ° each time the digital data forming the command data or the like changes, and the responder resonates. The change in the digital value of the command data is detected by the sharp change in the amplitude that occurs when the carrier wave whose phase is inverted from the interrogator received by the circuit overlaps with the vibration energy remaining in the resonance circuit. Contactless data communication method. 2. The interrogator transmits a carrier wave modulated by command data or the like to the responder, and the responder receives and demodulates the carrier wave by a resonance circuit, and the interrogator responds to the command or the like according to the instruction. In the non-contact data transmission / reception method of transmitting response data to the interrogator, the interrogator inverts the phase of the carrier wave by 180 ° for every 1 bit of the digital value forming the command data, and the interrogator inquires the phase of the carrier wave. After reversing, the wave number of the carrier until the next phase is reversed is transmitted by changing the digital data according to the digital data, and the responder receives the carrier wave whose phase is reversed from the interrogator received by the resonance circuit and the resonance circuit. The start or end of 1 bit of the digital value is detected by the sharp change in the amplitude caused by the overlapping of the remaining vibration energy, and Non-contact data communication method characterized by determining a digital value the interrogator is sent from the change in the amplitude carrier wave of wave number to change in the next amplitude is generated or time. 3. The responder according to claim 1 or 2, wherein the carrier wave extracted from one end of the resonance circuit is used to detect a change in the amplitude by envelope detection, and the phase of the carrier wave from the interrogator is detected. A non-contact data communication method, which is characterized by detecting a change in the data. 4. The transponder according to claim 1 or 2, wherein the carrier wave extracted from one end of the resonance circuit is input to the first inverter, and the carrier wave extracted from the other end of the resonance circuit is input to the second inverter. Non-contact data communication, characterized by detecting the change in the phase of the carrier wave from the interrogator from the signal obtained by ORing the outputs of the first and second inverters Method. 5. The transponder according to claim 1 or 2, wherein the transponder inputs a carrier extracted from one end of the resonance circuit to the first inverter, while the transponder extracts the carrier extracted from the same end of the resonance circuit into the second inverter. To the output of the second inverter and a feedback of the output of the second inverter by a resistor, the exclusive OR of the outputs of the first and second inverters, and the output of the filtered signal from the interrogator. A non-contact data communication method, which is characterized by detecting a change in the phase of a carrier wave. 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 device that transmits response data from the transponder to the interrogator, the interrogator has a code obtained by inverting the phase of the carrier by 180 ° whenever the digital value forming the command data or the like changes. , A modulator for performing modulation according to the code generated by the controller, a transmitter for transmitting the carrier wave modulated by the modulator, and the interrogator from the interrogator. The digital value of the above command data changes due to a sharp change in the amplitude that occurs when the phase-inverted carrier wave received from the interrogator received by the resonance circuit that receives the transmitted digital signal overlaps with the vibration energy remaining in the resonance circuit. A non-contact data transmission / reception device, comprising a demodulation unit for detecting a change. 7. 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 a non-contact data transmitter / receiver for transmitting response data from the transponder to the interrogator, the interrogator inverts the phase of a carrier wave by 180 ° for each bit of a digital value forming command data or the like, and After inverting the phase of the carrier wave, a control unit that generates a code that makes the wave number of the carrier wave until the next phase inversion changes according to the digital value, and modulates according to the code generated by this control unit. And a receiving means for receiving the inverted carrier wave from the interrogator in the transponder, and a transmitting means for transmitting the carrier wave modulated by the modulating section. Waveform shaping circuit that shapes the received carrier wave and abrupt changes in amplitude that occur due to overlapping of the above carrier wave and vibration energy remaining in the resonance circuit , A phase inversion detection circuit for detecting the start or end of one bit of the digital value, a clock generation circuit for generating a clock from the outputs of the phase inversion detection circuit and the waveform shaping circuit, the clock generation circuit and the phase A counter that counts the wave number of the digital value from the output of the inversion detection circuit, a data determination unit that determines the digital value from the output of the counter, and a control that controls the access to the memory and the like by the output of the data determination unit A non-contact data communication device having a section.