JPH09214366A - Data communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the communication range and to conduct accurate data communication at a high speed in the communication system where data commu nication is conducted between equipments while one equipment supplies power to the other equipment. SOLUTION: A data reader 10 sends a carrier SC0 with a low frequency f0 at all times and a tag 30 being carried in the vicinity of the reader 10 uses a rectifier circuit 32 to rectify the carrier SC0 so as to allow the reader 10 to generates an operating power for itself. Furthermore, the data reader 10 uses a synchronizing circuit 18 to synchronize transmission data DX with the carrier SC0 and a modulation circuit 20 applies amplitude modulation to the data by a carrier SCI whose frequency is a high frequency f1 (f1>f0) and the modulated signal is sent as a transmission for data communication. When the tag 30 receives the signal, a clock generating circuit 34 demodulates the data based on a reference clock CK generated from the received carrier SC0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication apparatus used in a communication system in which one communication apparatus supplies power to the other communication apparatus while performing non-contact data communication between the respective apparatuses.

[0002]

2. Description of the Related Art Conventionally, an ID code for identification is assigned to a person entering or leaving a facility such as a parking lot or a game hall, or a predetermined individual such as an article flowing through a transportation line at a production factory or a distribution center. A memory card having a stored communication function (personal I
A D card, a tag for goods, etc.) is provided, and a communication device capable of data communication with a memory card is provided on the passage route (entrance / exit gate, near the transportation line, etc.) of an individual, and a memory is provided via this communication device. Writing data to the card
By reading out, the individual passing through the passage is identified, and predetermined management operations such as entry / exit restrictions and switching of the destination of goods are automatically performed.
Management communication systems are known.

Further, in this type of communication system, if a power supply device such as a battery is provided on the memory card side, the weight of the memory card increases and the usability deteriorates. The communication device for reading has a function of supplying power to the memory card, so that the communication device supplies power to the memory card while performing data communication between the communication device and the card. That is, in this type of communication system, a transmission signal obtained by modulating a carrier wave with transmission data (amplitude modulation, frequency modulation, phase modulation, etc.) is transmitted from the communication device side,
On the memory card side, the received signal is rectified to generate its own operating power, so that the memory card is made battery-less.

However, in this type of communication system, it is necessary to increase the frequency of the carrier wave in order to perform high speed communication, and conversely, in order to secure the power supplied to the memory card, the frequency of the carrier wave is lowered. Since it is necessary, if the data transmission from the communication device to the memory card is performed by one carrier wave, there is a problem that it is not possible to achieve both power supply to the memory card and high speed communication.

In other words, in order to realize such a communication system as a communication facility that does not require legal approval, it is necessary to satisfy the specified value under the Radio Law. In the case of inductive communication equipment, the specified value is λ / 2π according to the current law.
The electric field strength at the point of (λ: wavelength, π: pi) is 15μ
It should be V / m or less. Therefore, in order to increase the communication distance between the communication device and the memory card and secure the power supply to the memory card, it is necessary to lower the frequency of the carrier wave. However, since the communication speed is proportional to the frequency of the carrier wave, the frequency of the carrier wave must be increased in order to speed up the communication. As a result, if data and power are transmitted from the communication device side to the memory card in one carrier wave, it becomes impossible to achieve both power supply to the memory card and high-speed communication. .

[0006]

On the other hand, such a problem is different from the carrier wave for data transmission in the power supply to the memory card, as disclosed in JP-A-62-212589, for example. This can be solved by using a carrier wave. That is, as disclosed in the above publication, power supply and data transmission are performed using carrier waves having mutually different frequencies, and further, in order to supply power to the memory card, in order to increase the power supply possible distance. A low frequency carrier wave is used for data communication, and a high frequency carrier wave that can realize high speed communication is used for data communication.

However, with such a configuration, although the data transmission itself from the communication device side to the memory card can be performed at high speed, the memory card side receiving the transmission signal can favorably demodulate the data. I can't
There is a problem that the accuracy of data transmission decreases.

That is, in order to demodulate data from a received signal, it is necessary to detect changes in the amplitude, frequency, phase, etc. of the received signal, and in order to perform the detection accurately, the received signal (in other words, data It is desirable to use a reference clock that is synchronized with the above), but in the device disclosed in Japanese Patent Laid-Open No. 62-212589, such a reference clock cannot be supplied from the communication device side to the memory card, and therefore the memory card side itself. The data must be demodulated using the internal clock generated by the. Therefore, the higher the frequency of the carrier wave used for data transmission from the communication device side, the lower the accuracy of data demodulation on the memory card side.

Therefore, even if the technique disclosed in Japanese Patent Laid-Open No. 62-212589 is used to perform power supply to the memory card and data communication using carrier waves of different frequencies, accurate data communication is possible. In order to realize the above, it is necessary to perform data transmission using a carrier wave of a relatively low frequency that can accurately demodulate data on the memory card side, and the communication speed is increased by increasing the distance at which power can be supplied to the memory card. It cannot be improved.

The present invention has been made in view of these problems, and in a communication system for realizing data communication between each of these devices by supplying power from one communication device to the other, An object of the present invention is to make it possible to increase the communication distance over which power can be supplied from one communication device to the other communication device, and also to perform accurate data communication at high speed.

[0011]

According to another aspect of the present invention, there is provided a data communication apparatus as set forth in claim 1, wherein the first carrier wave generating means supplies power and a reference clock to an external device which is a communication partner. A first carrier having a predetermined frequency to be supplied is generated, and the first transmitting means transmits the first carrier to the external device via the antenna. Further, the second carrier wave generating means generates a second carrier wave having a frequency higher than that of the first carrier wave, the modulating means modulates the second carrier wave with transmission data to be transmitted to an external device, and the synchronizing means transmits. The transmission signal modulated by the data or the modulation means is synchronized with the first carrier wave. Then, the second transmission means transmits the transmission signal modulated by the modulation means and synchronized with the first carrier wave by the synchronization means to the external device via the antenna.

That is, in the data communication apparatus according to the first aspect, the operating power is supplied to the external apparatus while transmitting the first carrier having a low frequency from the first transmitting means while satisfying the above-mentioned regulation by the Radio Law. By increasing the possible communication distance and transmitting a transmission signal in which the second carrier having a high frequency is modulated with the transmission data from the second transmitting means, the data can be transmitted at high speed to the external device. . Then, as described above, if the second carrier wave for data transmission is simply made to have a high frequency, the accuracy of demodulating data on the external device side is reduced, and eventually the communication speed cannot be increased. Alternatively, the modulated transmission signal is synchronized with the first carrier wave, and when the transmission signal is demodulated on the side of the external device, the reference clock for demodulation synchronized with the first carrier wave is generated so that the data is accurately transmitted. Enable demodulation.

Therefore, according to the data communication apparatus of the present invention (Claim 1), the external apparatus can be operated even if the distance to the external apparatus becomes long, and the data communication with the external apparatus can be performed. It becomes possible to perform communication at high speed while ensuring communication accuracy. It should be noted that the frequency of the first carrier wave for power supply should be set in the range of approximately 100 kHz to 550 kHz in consideration of the current law and the usage status of radio waves by other systems (specifically, the broadcasting band of AM radio, etc.). Good.

Since the data is transmitted in synchronization with this first carrier wave, if the frequency of the first carrier wave is f0, the communication speed is f0 / n (n: positive integer 1,
2, 3, ...) and a communication speed of 100 kbps or higher can be realized, so that the communication speed can be made extremely higher than the communication speed (several kbps) realized by data transmission between computers in the related art. .

As the second carrier wave for data transmission, a frequency having a cycle number of about 10 cycles or more per 1 bit of data is preferable, and the higher the frequency, the more the communication accuracy can be improved. ,
When the first carrier is set as above, it is approximately 1M.
It is preferable to set the frequency to Hz or higher.

Next, in the data communication device according to the second aspect, the second carrier wave generating means is composed of an oscillator, and the first carrier wave generating means is composed of a frequency divider for dividing a signal from the oscillator. . Therefore, it is not necessary to use two oscillators to generate the first carrier wave and the second carrier wave, and the device configuration can be simplified.

Further, in the data communication apparatus according to the third aspect, at least the first transmitting means transmits the first carrier wave via the resonance antenna formed of the resonance circuit of the coil and the capacitor. This is because, for the second carrier wave as the transmission signal, if a microwave with an extremely short wavelength is used, a small antenna can be used for the transmission antenna, but the first carrier wave for power supply has a communication distance. This is because a low frequency with a long wavelength must be used in order to lengthen the wavelength, and if a commonly used antenna (for example, a half-wavelength antenna) is used, the device becomes extremely large. That is, in the present invention, by using a resonant antenna composed of a capacitor and a coil for at least the antenna that transmits the first carrier wave, this antenna and thus the entire apparatus can be downsized.

Of course, the transmission signal (second
Even if the frequency of the second carrier wave is relatively low, the device can be downsized by using the resonance antenna including the capacitor and the coil as the antenna for transmitting the carrier wave). Further, next, in the data communication apparatus according to the fourth aspect, the first transmitting unit and the second transmitting unit share the coil antenna including the coil and transmit the first carrier wave and the transmission signal, respectively. That is, in order to miniaturize the antenna that transmits the first carrier wave and the transmission signal (second carrier wave) and to realize the transmission antenna with one antenna, the frequencies of the first carrier wave and the second carrier wave are Due to the difference, it is not possible to use the resonant antenna of the device according to claim 3. Therefore, in the present invention, a coil antenna that can transmit signals of different frequencies at the same time is used as the transmission antenna for transmitting the first carrier wave and the transmission signal (second carrier wave), although the transmission gain is inferior to the resonance antenna. By doing so, this transmitting antenna can be realized by one antenna. Therefore, according to the present invention, the device can be made smaller than that of the third aspect.

On the other hand, the data communication device according to claim 5 receives data from the data communication device according to any one of claims 1 to 4, and performs data communication with the device. A communication device (corresponding to a memory card such as an ID card and a tag described in the section of the related art).

And, in the device of the present invention (claim 5),
The first carrier receiving means receives the first carrier from the first transmitting means, the rectifying means rectifies the received first carrier to generate electric power for operation, and the clock generating means, A reference clock is generated from the received first carrier. Also, in this device, the receiving / demodulating means is
The transmission signal from the second transmitting means is received via the antenna, and the data is demodulated by the received signal and the reference clock generated by the clock generating means.

As a result, according to the data communication apparatus of the present invention (Claim 5), the transmission data from the data communication apparatus according to any one of Claims 1 to 4 is converted into the first carrier wave (and thus the received signal). It is possible to accurately demodulate using a reference clock synchronized with, and by combining with the device according to any one of claims 1 to 4, while supplying power from one communication device to another communication device, It is possible to construct a communication system capable of performing data communication between devices at high speed and with high accuracy.

The data communication apparatus according to the present invention (Claim 5) is used as a memory card such as an ID card and a tag, and is required to be miniaturized. As described above, it is desirable that the receiving means for receiving the first carrier wave is configured to receive the first carrier wave via the resonance antenna formed of the resonance circuit of the coil capacitor.

Further, as described above, when constructing a communication system for performing data communication between a memory card such as an ID card and a tag and a management device for managing the movement of an individual to which the memory card is attached, The communication device on the management device side (that is, having a power supply function to another communication device).
7. The data communication device according to claim 5) not only transmits data, but also receives data from the memory card (that is, the data communication device according to claim 5, which operates by receiving power supply from another communication device). It is desirable to be able to send. That is, it is desirable that not only the data can be written to the memory card from the management device side, but also the data can be read from the memory card.

To this end, the data communication device according to any one of claims 1 to 4 further comprises a transmission signal from an external device via an antenna as described in claim 7. External data receiving / demodulating means for receiving and demodulating transmission data from an external device is provided, and the data communication device according to claim 5 or 6 further includes demodulation as described in claim 8. Transmission data generation means for generating predetermined transmission data according to the reception data demodulated by the means, and a predetermined carrier wave is modulated by the transmission data generated by the transmission data generation means, and the modulated transmission is performed. Data modulation / transmission means for transmitting a signal via the antenna may be provided.

That is, in this way, the data communication device (communication device B) which receives power supply in response to a data request from the data communication device (communication device A) side which supplies power to the communication partner by transmitting the first carrier wave. ) Side to transmit its own data, the communication device A side can receive and demodulate the transmitted data. Based on the demodulated data in the management device or the like connected to the communication device A, It becomes possible to recognize the communication device B and execute a predetermined processing operation for the communication device B.

In this case, the communication device B side can generate transmission data with the reference clock supplied from the communication device A, and the communication device A side can demodulate the data with the reference clock. Data communication from B to the communication device A can also be accurately executed.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration of a pair of data communication devices used in a communication system for managing articles flowing on a transportation line in a production factory, a distribution center, or the like.

As shown in FIG. 1, the communication system according to the present embodiment is provided with a data reading device 10 connected to a management device 2 for managing products, and a product identification code which is attached to each product flowing through a conveyance line. The tag 30 is stored in advance. Then, the data reader 10 and the tag 3
0 has a communication function of transmitting and receiving data in a contactless manner, and the data reading device 10 has a power supply function of supplying an operating power to the tag 30 in a contactless manner.

That is, the data reading device 10 corresponds to the data communication device according to any one of claims 1 to 4 and 7 capable of supplying power to the communication partner, and has a predetermined frequency f0.
(About 100 kHz to 550 kHz: 15 in this embodiment)
Oscillator 12 as a first carrier wave generating means for generating a sine wave signal Sc0 of 3.6 kHz, and a predetermined frequency f1 having a frequency higher than that of the sine wave signal Sc0 generated by the oscillator 12.
Oscillator 14 as second carrier generation means for generating a sine wave signal SC0 of 1 MHz or higher (8 MHz in this embodiment).
And a transmitter 16 as first transmitting means for transmitting the output signal (first carrier wave) SC0 from the oscillator 12 to the tag 30 via the transmitting antenna A1, and the transmission data DX generated by the management device 2. , This transmission data DX is generated by the oscillator 12
The synchronizing circuit 18 as a synchronizing means for synchronizing with the output signal SC0 from the oscillator, and the output signal (second carrier wave) SC1 from the oscillator 14 with the transmission data DX synchronized with the output signal SC0 from the oscillator 12 by the synchronizing circuit 18. A modulation circuit 20 as a modulation means for performing amplitude modulation, and a signal SX1 amplitude-modulated by the modulation circuit 20 is transmitted through a transmission antenna A2 to a tag 3
And a transmitter 22 as second transmitting means for transmitting to 0.

The data reading device 10 also includes a tag 30.
And a demodulation circuit for demodulating the reception signal SR2 from the receiver 24 using the reference clock synchronized with the output (first carrier wave) SC0 of the oscillator 12. 26, and the transmission data from the tag 30 demodulated by the demodulation circuit 26,
That is, the received data DR is input to the management device 2.

The receiver 24 and the demodulation circuit 26 correspond to the external data receiving / demodulating means of the present invention (claim 7). The transmitting antennas A1 and A2 and the receiving antenna A3 are each composed of a resonant antenna that transmits or receives a radio wave by utilizing resonance of a capacitor and a coil.

On the other hand, the tag 30 generates operating power by a transmission signal transmitted from the data reading device 10 via the transmission antenna A1, and performs data communication with the data reading device 10. It corresponds to the data communication device according to claims 6 and 8. The tag 30 has a transmission antenna A1 of the data reading device 10.
Receiving antenna B1 as a first carrier receiving means for receiving a transmitting signal from the data reading device 10 and a transmitting signal (first carrier) received by the receiving antenna B1 from the data reader 10.
A rectifying circuit 32 as a rectifying means for rectifying the electric power (voltage Vo) for operation and a transmission signal from the data reading device 10 which is also received by the receiving antenna B1 and receives, for example, a zero cross point of this signal. By receiving the transmission signal from the transmission antenna A2 of the data reading device 10 via the reception antenna B2, and a clock generation circuit 34 as a clock generation unit that generates a reference clock CK synchronized with the transmission signal. The received signal SRT1 is used as a reference clock CK generated by the clock generation circuit 34.
Demodulating circuit 3 as receiving / demodulating means for demodulating using
6 are provided.

The tag 30 receives the transmission data from the data reading device 10 demodulated by the demodulation circuit 36, that is, the reception data DRT, and performs a preset processing operation corresponding to the reception data DRT. A control circuit 40 including a computer is provided. The control circuit 40 is designed to operate with the reference clock CK generated by the clock generation circuit 34, and receive data D
According to RT, reading and writing of data from the memory 42, control of tag operation, etc. are performed, and if necessary, predetermined transmission data DXT such as the ID code unique to the tag 30 read from the memory 42 is used as the reference clock CK. And output sequentially in synchronization with.

The tag 30 is provided with the control circuit 40.
The transmission data DXT outputted from the modulator modulates a carrier wave of a predetermined frequency f2, which is generated by an oscillator (not shown) and has a frequency higher than at least the reference clock CK, and the modulated signal is used as a response signal to the data reading device 10 to transmit the signal. Send to the data reading device 10 via B3,
A modulation circuit 38 as a data modulation / transmission means is provided.

The transmitting antenna B3 and the receiving antennas B1 and B2 provided on the tag 30 utilize the resonance between the capacitor and the coil, similarly to the transmitting antennas A1 and A2 and the receiving antenna A3 on the data reading device 10 side. It is composed of a resonant antenna that transmits or receives radio waves.

In the article management communication system of the present embodiment configured as described above, as shown in FIG.
The data reading device 10 receives the tag 3 from the transmission antenna A1.
The carrier wave Sc0 having the frequency f0 for supplying electric power to 0 is constantly transmitted, and the tag 30 is transmitted from the transmission antenna A2.
A transmission signal SX1 for reading ID data and the like is periodically transmitted. This transmission signal SX1 is transmitted by the modulation circuit 20 from the transmission data DX from the management device 2 to the frequency f1 (f1
> F0), which is an amplitude-modulated signal with the carrier wave SC1.
The transmission data DX is a carrier wave S transmitted from the transmission antenna A1 by the synchronization circuit 18 before being input to the modulation circuit 20.
Since it is synchronized with C0, the transmission signal SX1 is always synchronized with the carrier wave SC0.

The tag 30 is used as the data reading device 10.
When entering the nearby communication area where power can be supplied, the receiving antenna B1 receives the carrier wave SCO transmitted from the data reading device 10, and the rectifying circuit 32 in the tag 30 rectifies the received carrier wave SCO. As a result, it generates its own operating power (power supply voltage Vo) and activates the internal circuit of the tag 30. Then, the clock generation circuit 34 generates a reference clock (tag clock shown in the figure) CK for operation in synchronization with the received carrier wave SCO. On the tag 30 side, the reception antenna B2 receives the transmission signal SX1 from the data reading device 10, and the demodulation circuit 36 uses the reception signal SRT1 with the reference clock CK (in the figure, the fall of the reference clock CK). By demodulating (at the timing), transmission data (tag / reception data) DRT from the data reading device 10 is generated.

Therefore, according to the communication system of this embodiment, when the article to which the tag 30 is attached enters the communication area near the data reading device 10, the tag 30 transmits the data from the data reading device 10. The signal SX1 can be demodulated by the reference clock CK synchronized with the data before the modulation of the signal, and the demodulation accuracy of the data can be improved even if the communication speed is high. In addition, a carrier SC0 having a relatively low frequency (frequency f0) is used to supply power from the data reader 10 to the tag 30, and the electric field strength at the point of λ / 2π is 15 μV /
The data reading device 10 and the tag 30 while satisfying the regulations under the current law for inductive communication equipment such as m or less.
The communication distance to the tag 30 can be increased (in other words, the communication area in which the tag 30 can operate by receiving the power supply from the data reading device 10 is widened), and moreover, the data from the data reading device 10 to the tag 30 can be increased. For transmission, the carrier wave S of higher frequency (frequency f1) than the carrier wave SC0 for power supply is used.
Since C1 is used, the transmission data DX synchronized with the carrier wave SC0 for power supply can be favorably modulated as a transmission signal for data transmission, which also improves the demodulation accuracy of data on the tag 30 side. can do.

Therefore, according to the present embodiment, the communication distance over which power can be supplied from the data reading device 10 to the tag 30 is increased, and data communication between these devices is performed at high speed while ensuring communication accuracy. You can Next, when the tag 30 receives power from the data reading device 10 and demodulates the transmission data from the data reading device 10 as described above, the demodulated reception data DRT is input to the control circuit 40. . Then, in the control circuit 40, as described above, the data (ID code or the like) to be transmitted to the data reading device 10 according to the received data DRT.
Is read from the memory 42, and the read transmission data DXT is output in synchronization with the reference clock CK.

Then, as shown in FIG. 2B, the tag 30
In the inside, the modulation circuit 38 modulates a carrier wave of frequency f2 (f2> f0) according to the transmission data DXT and transmits it from the transmission antenna B3. On the data reading device 10 side, the transmission signal SXT2 is transmitted via the reception antenna A3. To receive. Then, in the data reading device 10, the receiving antenna A
The reception signal SR2 from the signal No. 3 is demodulated by the demodulation circuit 26, and the demodulated reception data DR is transferred to the management device 2.

Therefore, according to the communication system of this embodiment, the data unique to the tag 30 (and hence the article to which the tag 30 is attached) can be read on the side of the data reading device 10 and the data flow on the carrying line. It is possible to automatically manage the number of articles and the destination of the articles. In the case of data transmission from the tag to the data reading device 10 as well, since the data is generated by the reference clock CK synchronized with the carrier wave SC0 transmitted from the data reading device 10 side, the data reading device 10 On the side, by demodulating the reception signal SR2 in synchronization with the carrier wave SC0, the transmission data from the tag 30 can be demodulated with high accuracy, and the data communication from the tag 30 to the data reading device 10 is also performed. It can be performed at high speed and with high accuracy.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can take various modes. Therefore, next, another configuration example of the data reading device 10 is shown in FIGS. 3 to 7 and another configuration example of the tag 30 is shown in FIG. 8, respectively, and the differences from those shown in FIG. 1 will be described respectively.

First, FIG. 3 shows a second configuration example of the data reading device 10. As shown in FIG. 3, in the data reading device 10-2, in the data reading device 10 shown in FIG. 1, the synchronizing circuit 18 is provided in the preceding stage of the modulating circuit 20, while the synchronizing circuit 18 is provided in the modulating circuit 20. The synchronization circuit 18 is provided in the subsequent stage, and the transmission signal modulated by the modulation circuit 20 is synchronized with the carrier wave SC0 for power supply and input to the transmitter 22. Even if the data reading device 10 is configured in this way, the amplitude change of the transmission signal can be synchronized with the carrier wave SC0 for power supply, so that the tag 30 side can read the data reading device 10-2.
1 can accurately demodulate the transmission signal SX1 from FIG.
It is possible to obtain the same effect as the embodiment shown in FIG.

Next, FIG. 4 shows a third configuration example of the data reading device 10. As shown in FIG. 4, in the data reading device 10-3 shown in FIG. 1, in the data reading device 10 shown in FIG. 1, a carrier wave SCO for power supply and a carrier wave SC1 for data transmission are respectively supplied to dedicated oscillators 12, The oscillator for carrier wave generation is
Carrier wave SC1 (frequency f1) for high frequency data transmission
By using only the oscillator 14 for generating, and dividing the carrier wave SC1 from this oscillator 14 by the frequency divider 28,
It is configured to generate a carrier wave SC0 (frequency f0) for power supply. In the case of such a configuration, it is not necessary to use two oscillators to generate the two types of carriers SC0 and SC1, and it is possible to realize with one oscillator and a frequency divider. The cost can be reduced compared to the data reading device 10.

Next, FIG. 5 shows a fourth configuration example of the data reading device 10. As shown in FIG. 5, the data reading device 10-4 directly supplies the signal (the operation clock of the management device 2) from the oscillator 2b that generates the operation clock of the CPU 2a that generates the transmission data DX in the management device 2 as it is. The data reading device 10 shown in FIG. 1 is configured by transmitting the carrier wave SC0 for supply to the tag 30.
From which the oscillator 12 and the synchronizing circuit 18 are excluded. That is, in the management device 2, the CPU 2a generates the transmission data DX with the operation clock generated by the oscillator 2b, so that the operation clock is used as the carrier wave S for power supply.
If it is transmitted to the tag 30 as C0, the management device 2
The transmission data DX output from is always synchronized with the carrier wave SC0, and the present invention can be realized without separately providing the synchronizing circuit 18 in the data reading device 10-4. In this case, the oscillator 2b in the management device 2 functions as the first carrier wave generating means,
The CPU 2a in the management device 2 will function as a synchronization unit.

FIG. 6 shows a fifth configuration example of the data reading device 10. As shown in FIG. 6, this data reading device 10-5 is the same as the data reading device 10 shown in FIG.
6 and 22 are configured to transmit the carrier wave SC0 or the transmission signal SX1 by using the dedicated transmission antennas A1 and A2, respectively, while the outputs of the transmitters 16 and 22 are coil antennas. By connecting to one transmitting antenna A12, each transmitter 16 and 22 is connected to this transmitting antenna A12.
12 is shared to transmit the carrier wave SC0 and the transmission signal SX1. Therefore, according to the data reading device 10-5, the number of antennas can be two, the device configuration can be simplified, the device can be reduced in size and weight, and the device can be realized at low cost. . A coil antenna is used as the transmission antenna A12 because the carrier SC0 and the transmission signal SX1 (in other words, the carrier SC
This is because the frequency is different from that of 1) and it is not possible to use the resonant antenna that utilizes the resonance between the capacitor and the coil as in the above-described embodiment.

Next, FIG. 7 shows a sixth configuration example of the data reading device 10. As shown in FIG. 7, in the data reading device 10-6, in the data reading device 10 shown in FIG. 1, the receiving antenna A3 that receives the transmission signal from the tag 30 is separated from the transmitting antennas A1 and A2. In contrast to the above configuration, the output of the transmitter 22 for data transmission and the input of the receiver 24 for data reception from the tag 30 are transmitted and received by utilizing the resonance between the capacitor and the coil. One transmitting / receiving antenna A consisting of possible resonant antennas
By connecting to the tag 23, data transmission / reception with the tag 30 can be performed by sharing the transmission / reception antenna A23. Therefore, also in the data reading device 10-6, two antennas can be provided, the device configuration can be simplified, the device can be reduced in size and weight, and the device can be realized at low cost. In addition, in this way, one transmitting / receiving antenna A
When 23 is used, it is necessary to use the carrier having the same frequency f1 as the carrier SC1 for the data transmission from the tag 30.

On the other hand, FIG. 8 shows a second configuration example of the tag 30. As shown in FIG. 8, in the tag 30-2 shown in FIG. 1, in the tag 30 shown in FIG. 1, a reception antenna B2 for receiving the transmission signal SX1 from the data reading device 10 and a transmission antenna B3 for transmitting the data DXT are provided. In contrast to the separate structure, the data receiving demodulation circuit 36 and the data transmitting modulation circuit 38 are connected to one transmission / reception antenna B23, which is a resonant antenna, so that This transmission / reception antenna B
23 is configured to be shared and executed.
Therefore, in this tag 30, two antennas can be provided, the device configuration can be simplified, the device can be made smaller and lighter, and it can be realized at low cost. When one transmission / reception antenna B23 is used for data transmission / reception in this way, the carrier wave used for data modulation in the modulation circuit 38 has the same frequency f1 as the carrier wave SC1 used for data modulation in the data reader 10 side. Need to

As described above, the present invention provides the data reader 1.
In configuring a communication system including 0 and a tag 30, the data reading device 10 can be realized in various configurations as illustrated in FIGS. 1 and 3 to 7, and the tag 30 Can be realized by various configurations as illustrated in FIGS. 1 and 8. Then, each of these devices can take more modes by combining the characteristic parts described in the above drawings with each other.
Further, the combination of the data reading device 10 and the tag 30 can be variously changed.

In the above embodiment, the communication system for inter-article use consisting of the data reading device 10 and the tag 30 for managing the articles moving on the conveying line etc. has been described as an example. A non-contact type that performs data communication between devices while supplying power from one communication device to the other, such as an entrance / exit management system that manages people entering and leaving the facility. It goes without saying that any communication system of a communication system can be applied to any communication system.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a data reading device and a tag used in a communication system of an embodiment.

FIG. 2 is a time chart illustrating a communication operation performed between a data reading device and a tag.

FIG. 3 is a configuration diagram illustrating a second configuration example of a data reading device.

FIG. 4 is a configuration diagram illustrating a third configuration example of a data reading device.

FIG. 5 is a configuration diagram illustrating a fourth configuration example of a data reading device.

FIG. 6 is a configuration diagram illustrating a fifth configuration example of a data reading device.

FIG. 7 is a configuration diagram illustrating a sixth configuration example of a data reading device.

FIG. 8 is a configuration diagram illustrating a second configuration example of a tag.

[Explanation of symbols]

2 ... Management device 2a ... CPU 2b ... Oscillator 10 ... Data reading device 12, 14 ... Oscillator 1
6, 22 ... Transmitter 18 ... Synchronous circuit 20 ... Modulation circuit 24 ... Receiver
26 ... Demodulation circuit 28 ... Frequency divider 30 ... Tag 32 ... Rectifier circuit 3
4 ... Clock generation circuit 36 ... Demodulation circuit 38 ... Modulation circuit 40 ... Control circuit 42 ... Memory A1, A2, A12, B3 ... Transmission antenna A3, B1, B2 ... Reception antenna A23, B23 ...
Transmit / receive antenna

Claims (8)

[Claims] 1. A data communication device for supplying power to an external device having a communication function and performing data communication with the device, wherein the data communication device supplies power and a reference clock to the external device. First carrier generating means for generating a first carrier of a predetermined frequency, first transmitting means for transmitting the first carrier generated by the first carrier generating means to the external device via an antenna, and the first carrier A second carrier wave generating means for generating a second carrier wave having a high frequency; a modulating means for modulating the second carrier wave with transmission data to be transmitted to the external device; Synchronization means for synchronizing the transmission signal with the first carrier wave; and the synchronization means for modulating the first signal by the synchronization means.
And a second transmitting means for transmitting a transmission signal synchronized with a carrier wave to the external device via an antenna, the data communication device. 2. The second carrier generation means comprises an oscillator, and the first carrier generation means comprises a frequency divider that divides a signal from the oscillator. Data communication device. 3. The data according to claim 1, wherein at least the first transmission means transmits the first carrier wave via a resonance antenna formed of a resonance circuit of a coil capacitor. Communication device. 4. The first transmitting means and the second transmitting means share a coil antenna composed of a coil to transmit the first carrier wave and the transmission signal, respectively. Item 2. The data communication device according to item 2. 5. A data communication device which receives power from the data communication device according to any one of claims 1 to 4 and performs data communication with the device, the data communication device transmitting from the first transmitting means. First carrier receiving means for receiving the first carrier thus generated, rectifying means for rectifying the first carrier received by the first carrier receiving means to generate electric power for operation, and the first carrier receiving means. And a clock generation means for generating a reference clock from the first carrier wave received by the second transmission means, the transmission signal from the second transmission means being received via an antenna, and the received reception signal and the clock generation means being generated. And a receiving / demodulating means for demodulating data according to the reference clock. 6. The data communication apparatus according to claim 5, wherein the first carrier wave receiving means receives the first carrier wave via a resonance antenna formed of a resonance circuit of a coil capacitor. 7. The data communication device according to claim 1, further comprising external data for receiving a transmission signal from the external device via an antenna and demodulating the transmission data from the external device. A data communication device comprising a receiving / demodulating means. 8. A data communication device which receives power from the data communication device according to claim 7 and performs data communication with the device, wherein the data according to claim 5 or 6. For communication devices,
Further, a transmission data generation unit that generates predetermined transmission data according to the reception data demodulated by the demodulation unit, and a predetermined carrier wave that is modulated by the transmission data generated by the transmission data generation unit, A data communication device, comprising: a data modulation / transmission means for transmitting a modulated transmission signal via an antenna.