JP2011199395A - Electric field communication device for installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce erroneous recognition of a passing person when passing through a gate.SOLUTION: A carrier wave reproducing section 14 reproduces a carrier wave from a signal received by a first installed electrode 11a, a first synchronization detecting section 16a synchronously detects the reproduced carrier wave and a signal received by the first installed electrode 11a to reproduce the signals into information to be received, and a second synchronization detecting section 16b synchronously detects the reproduced carrier wave and the signal received by the second installed electrode 11b to reproduce the signals into information to be received. Then, a polarity inversion detecting section 18 collates each of the reproduced information to be received to detect whether the polarity is inverted, and if so, outputs a polarity inversion detecting signal. After that, a transceiver control section 19 processes the information to be received when receiving the polarity inversion detecting signal, as effective information.

Description

  The present invention relates to a technique for performing electric field communication by inducing an electric field from an electrode into an electric field transmission medium.

  2. Description of the Related Art Conventionally, there has been proposed an electric field communication apparatus that induces an electric field based on information to be transmitted to an electric field transmission medium and detects an electric field induced in the electric field transmission medium to perform communication (see Patent Document 1). reference).

  Here, a conventional electric field communication apparatus for installation using such a conventional electric field communication apparatus for an entrance / exit (hereinafter referred to as a gate) of a ticket gate or a store will be described. FIG. 12 is a top view showing a state where identification information and the like of a passing person passing through the gate are acquired. The electric field communication apparatus 1 for installation is installed inside or outside the gate 3, and is electrically connected to the installation electrode 11 installed in one side area of the gate 3 on the side through which the passer A passes and transmits. It is communicably connected to an information processing apparatus (not shown) such as a personal computer that processes the received information as a higher system. In addition, since the process of inducing electric field in the electric field transmission medium and transmitting / receiving information in the installation electric field communication device 1 is the same as that described in Patent Document 1, description thereof is omitted.

  On the other hand, as shown in FIG. 13, the portable electric field communication device 7 possessed by the passer-by A includes the first electrode 72a and the second electrode 72b that induce an electric field in the electric field transmission medium. It is possible to perform electric field communication by inducing an electric field based on information to be transmitted to the electric field transmission medium by the transceiver 71 stored in the opposite surface of the casing forming the outer shape of the ing.

  Here, when the passing person A carrying the portable electric field communication device 7 passes close to the side surface of the gate 3, the floating that acts as an electric field transmission path between the passing person A and the installation electrode 11. A capacitor C is formed (see FIG. 12). Since the identification information of the passing person A is intermittently or continuously output as signals having different polarities (positive polarity signal and negative polarity signal) from the first electrode 72a and the second electrode 72b that are arranged opposite to each other, The electric field communication device 1 for a positive signal transmitted from the first electrode 72a via the transmission path (dotted arrow in FIG. 12) based on the passer A and the stray capacitance C acting as an electric field transmission medium and / or The negative polarity signal transmitted from the second electrode 72b is received by the installation electrode 11, demodulated into information to be received (such as identification information of the passer A), and then transmitted to the information processing apparatus at the subsequent stage.

  The latter information processing apparatus authenticates by using the transmitted identification information of the passer A, and determines whether or not to permit permission to pass through the gate (when authentication is successful, it is determined to be permitted, and when authentication is unsuccessful) In the case of non-permission, a rejection signal for rejecting the passage is output to prevent the passage person A from passing through the gate 3.

Japanese Patent Application Laid-Open No. 2004-274452 JP 2006-81111 A JP 2009-94961 A

  However, in many cases, a plurality of people pass through the gate 3 provided as a passage entrance to the inside and outside of the premises, and the passer-by B who passes next to the passer-A who is currently passing approaches the passer-by A. In such a case, as shown in FIG. 14, a stray capacitance C ′ is formed between the portable electric field communication device 7b possessed by the passer-by B and the passer-by A, and the portable electric field communication possessed by the passer-by A. In addition to the transmission path W1 formed with the device 7a, a transmission path W2 based on the stray capacitance C ′, the passer A and the stray capacitance C is also formed between the portable electric field communication device 7b of the passer B. As a result, the electric field radiated from the portable electric field communication device 7b is transmitted to the installation electrode 11 through the passer A, and there is a problem that erroneous communication is performed.

  This invention is made | formed in view of the said subject, and makes it a subject to reduce the misidentification of the passing person at the time of gate passage.

  The present invention according to claim 1 is used for a gate through which a mobile body having a portable electric field communication device that modulates signals having different polarities based on information to be transmitted and outputs the signals from different electrodes by an electric field. In the installation electric field communication device, the first installation electrode and the second installation electrode installed in the gate so as to receive the signal output from the portable electric field communication device through the mobile body by an electric field, Carrier wave reproducing means for reproducing a carrier wave from a signal received by the first installation electrode, and firstly reproducing the reproduced carrier wave and the signal received by the first installation electrode to information to be received by synchronous detection. Synchronous detection means, second synchronous detection means for synchronously detecting the reproduced carrier wave and the signal received by the second installation electrode, and reproducing the information to be received, and the first synchronous detector And collating each information to be received reproduced by the second synchronous detection means, detecting whether or not the polarity is inverted, and outputting the polarity inversion detection signal if the polarity is inverted And detecting means, and control means for processing the information to be received as valid information when the polarity reversal detection signal is received.

  According to the present invention, the first installation electrode and the second installation electrode installed on the gate so as to receive the signal output from the portable electric field communication device through the mobile body by the electric field, and the first installation electrode Carrier reproduction means for reproducing a carrier wave from the received signal, first synchronous detection means for synchronously detecting the reproduced carrier wave reproduced and the signal received by the first installation electrode, and reproducing the information to be received, reproduction The second synchronous detection means for synchronously detecting the carrier wave and the signal received by the second installation electrode to reproduce the information to be received, and each of the signals reproduced by the first synchronous detection means and the second synchronous detection means Check the information to be received, detect whether the polarity is reversed, and if it is reversed, the polarity reversal detection means that outputs the polarity reversal detection signal and the polarity reversal detection signal are received Information that should be received is valid information Since a control unit for processing as is possible to reduce the passage's false card when passing through the gate.

  According to a second aspect of the present invention, the first installation electrode and the second installation electrode have different polarities output from the portable electric field communication device when the passer passes the gate. It is arrange | positioned at the side surface of the said gate so that a signal may be received, respectively.

  According to a third aspect of the present invention, the gate has two side surfaces facing each other across the passage, the first installation electrode is disposed on one side surface, and the second installation electrode is the other side surface. It is arranged on the side surface so as not to face the first installation electrode.

  According to a fourth aspect of the present invention, the second synchronous detection means is arranged in the gate on the side where the second installation electrode is arranged, and a noise component of a signal received by the second installation electrode And amplifying / filtering means for amplifying the signal component in the preceding stage of the second synchronous detection means.

  According to a fifth aspect of the present invention, the gate has two side surfaces facing each other across a passage, and the first installation electrode and the second installation electrode are arranged on the two side surfaces. It is characterized by being.

  ADVANTAGE OF THE INVENTION According to this invention, the misidentification of the passing person at the time of passage through a gate can be reduced.

It is a figure which shows the functional block structure of the electric field communication apparatus for installation based on one Example. It is a figure which shows the signal cover area received by each installation electrode. It is a figure which shows the state at the time of normal when one passing person passes a gate. It is a figure which shows the state at the time of abnormality when a several passing person passes a gate. It is a figure which shows the example of installation which uses a ground electrode. It is a figure which shows the example of installation which uses a ground electrode. It is a figure which shows the example of installation of the 1st installation electrode and the 2nd installation electrode. It is a figure which shows the modified example at the time of function separation. It is a figure which shows the functional block structure of the electric field communication apparatus for installation after function separation. It is a figure which shows the functional block structure of a remote signal processing part. It is a figure which shows the example of installation of the 1st installation electrode and the 2nd installation electrode. It is a figure which shows the conventional electric field communication apparatus for installation. It is a figure which shows the structure of a portable electric field communication apparatus. It is a figure which shows the conventional electric field communication apparatus for installation.

  Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a functional block configuration of an installation electric field communication apparatus according to an embodiment. The installation electric field communication device 1 is provided inside or outside a gate 3 installed at an entrance of a ticket gate or a store, and includes a first installation electrode 11a, a second installation electrode 11b, 1 transmission / reception selector switch 12a, second transmission / reception selector switch 12b, first amplification / filter unit 13a, second amplification / filter unit 13b, carrier recovery unit 14, carrier detection unit 15, 1 synchronous detection part 16a, 2nd synchronous detection part 16b, waveform shaping part 17, polarity inversion detection part 18, transceiver control part 19, modulation part 20, and output part 21 are comprised. . Hereinafter, configurations and functions of these functional units will be described.

  The first installation electrode 11a is arranged in one region of the side surface of the gate 3 on the passing side where the passing person A passes through the gate 3, and between the passing person A when the passing person A passes close to the side surface of the gate 3. The signal transmitted from the portable electric field communication device 7 possessed by the passing person A is received by the electric field through the stray capacitance formed in the terminal and the passing person A acting as an electric field transmission medium.

  The second installation electrode 11b is disposed adjacent to the first installation electrode 11a along the traveling direction so that it appears next to the first installation electrode 11a when the passer A passes through the gate 3. Similar to the above function of the installation electrode 11a, the passing person A passes through the stray capacitance formed between the passing person A and the passing person A acting as an electric field transmission medium when passing through the side surface of the gate 3. Thus, it has a function of receiving a signal transmitted from the portable electric field communication device 7 possessed by the passer A by an electric field.

  The first transmission / reception selector switch 12a is connected to the electrode terminal a1 connected to the first installation electrode 11a, the reception terminal b1 connected to the first amplification / filter unit 13a, and the output unit 21. The connection terminal of the electrode terminal a1 is switched to the reception terminal b1 or the transmission terminal c1 according to the contents of the control signal S from the transceiver control unit 19 (the contents will be described later). It has a function.

  The second transmission / reception selector switch 12b is connected to the electrode terminal a2 connected to the second installation electrode 11b, the reception terminal b2 connected to the second amplification / filter unit 13b, and the output unit 21. In the same manner as the above-described function of the first transmission / reception change-over switch 12a, the connection destination of the electrode terminal a2 is determined as the reception terminal in accordance with the content of the control signal S from the transceiver control unit 19. b2 or the function of switching to the transmission terminal c2.

  The first amplification / filter unit 13a is connected to the reception terminal b1 of the first transmission / reception change-over switch 12a, and amplifies the signal received by the first installation electrode 11a via the first transmission / reception change-over switch 12a. After removing unnecessary frequency components such as noise, it has a function of outputting to the first synchronous detector 16a, the carrier recovery unit 14, and the carrier detector 15.

  The second amplification / filter unit 13b is connected to the reception terminal b1 of the second transmission / reception selector switch 12b, and the second transmission / reception selector switch 12b is similar to the function of the first amplification / filter unit 13a. The signal received by the second installation electrode 11b via the signal is amplified, and unnecessary frequency components such as noise are removed, and then output to the second synchronous detector 16b.

  The carrier recovery unit 14 has a function of reproducing a carrier from the output signal of the first amplification / filter unit 13a and outputting the reproduced carrier to the first synchronous detection unit 16a and the second synchronous detection unit 16b. ing.

  The carrier wave detection unit 15 has a function of detecting a carrier wave from the output signal of the first amplification / filter unit 13 a and outputting the detected carrier wave detection signal to the waveform shaping unit 17.

  The first synchronous detection unit 16a has a function of synchronously detecting the recovered carrier wave output from the carrier wave recovery unit 14 and the output signal of the first amplification / filter unit 13a and reproducing the information to be received. Yes.

  The second synchronous detection unit 16b performs synchronous detection on the reproduced carrier wave output from the carrier wave reproduction unit 14 and the output signal of the second amplification / filter unit 13b in the same manner as the above-described function of the first synchronous detection unit 16a. Thus, it has a function of reproducing information to be received.

  In some cases, the waveform shaping unit 17 may invert the phase of the signal received by the first installation electrode 11a and the reproduced carrier wave reproduced by the carrier wave reproducing unit 14, and in this case, the first synchronous detection unit 16a. Since the polarity of the information to be received that has been received is inverted, it has a function of correcting the polarity inversion using the carrier detection signal detected by the carrier detection unit 15 and outputting it to the transceiver control unit 19 ing. As a method for correcting the polarity reversal, for example, methods disclosed in Patent Documents 2 and 3 can be used. Further, as shown in FIG. 15 of Patent Document 3, it is possible to correct the polarity inversion without using the carrier wave detection signal.

  The polarity inversion detection unit 18 receives the information to be received reproduced by the first synchronous detection unit 16a and the second synchronous detection unit 16b, and collates the two received information to be received (data comparison). Thus, it has a function of detecting whether or not the polarity is reversed, and outputting the polarity reversal detection signal to the transceiver control unit 19 when the polarity is reversed.

  When the polarity inversion detection signal is input, the transceiver control unit 19 transmits the corrected information to be received output from the waveform shaping unit 17 to the information processing apparatus as valid, and the polarity inversion signal is received. If it is not input, it has a function of discarding the information to be received or treating it as invalid.

  The modulation unit 20 has a function of modulating information transmitted from the information processing apparatus through the transceiver control unit 19 and outputting the modulated signal to the output unit 21.

  The output unit 21 is connected to the transmission terminal c1 of the first transmission / reception changeover switch 12a and the transmission terminal c2 of the second transmission / reception changeover switch 12b, and is modulated by the modulation unit 20 (transmitted from the information processing apparatus). A signal obtained by modulating information) from the first installation electrode 11a and the second installation electrode 11b. Specifically, the modulated signal is inverted and non-inverted, and the non-inverted signal is output as the positive polarity signal from the first installation electrode 11a and inverted in the same manner as the portable electric field communication device 7 described later. The signal is output from the second installation electrode 11b as a negative signal.

  In the installation electric field communication apparatus 1, the process of inducing an electric field from the first installation electrode 11a and the second installation electrode 11b to the electric field transmission medium to transmit and receive information is the same as that described in Patent Document 1. Therefore, the description is omitted.

  Next, the processing operation of the installation electric field communication apparatus 1 in the present embodiment will be described. Note that the portable electric field communication device 7 possessed by the passer-by A, as described with reference to FIG. 13, generates an electric field based on information to be transmitted (for example, identification information of the passer-A), etc. A transceiver 71 that induces electric field communication and modulates information to be transmitted at a predetermined frequency, and outputs a signal of one polarity (hereinafter referred to as a positive polarity signal) from the first electrode 72a. It is assumed that a signal of the other polarity (hereinafter referred to as a negative polarity signal) is output from the second electrode 72b arranged to face the first electrode 72a. In addition, the passer-by A faces such a portable electric field communication device 7 with the first electrode 72a facing inward (the side with the body) and the second electrode 72b facing outward (the side without the body). Assume that you have it in a state.

  Here, when the passer-by A passes through the gate 3, as shown in FIG. 2, the electric field communication area in which electric field communication is performed with the positive signal output from the first electrode 72 a of the portable electric field communication device 7 is the first. An electric field communication area that covers one installation electrode 11a and performs electric field communication with a negative signal output from the second electrode 72b covers the second installation electrode 11b.

  Thereby, the first installation electrode 11a receives the positive polarity signal via the transmission path W1a based on the stray capacitance C1 formed between the passing person A and the passing person A as the electric field transmission medium, The second installation electrode 11b receives the negative polarity signal via the transmission path W1b based on the stray capacitance C2 formed between the second installation electrode 11b and the second electrode 72b.

  Here, a normal state in which only the passing person A passes through the gate 3 is shown in FIG. 3, and an abnormal state in which the passing person B trying to pass after the passing person A passes close to the passing person A Is shown in FIG.

  In the normal state shown in FIG. 3, the positive polarity signal output from the first electrode 72a is received by the first installation electrode 11a via the passer A and the stray capacitance C1, and from the second electrode 72b. The output negative polarity signal is received by the second installation electrode 11b via the stray capacitance C2.

  Then, the positive signal received by the first installation electrode 11a is amplified by the first amplification / filter unit 13a and regenerated to information to be received by the first synchronous detection unit 16a. On the other hand, the negative polarity signal received by the second installation electrode 11b is amplified by the second amplification / filter unit 13b and regenerated to information to be received by the second synchronous detection unit 16b.

  The carrier recovery unit 14 recovers the carrier based on the output signal of the first amplification / filter unit 13a (a signal obtained by amplifying the positive polarity signal), and the signal polarity of each information to be received reproduced by each synchronous detection unit is Since the polarity is inverted, the polarity inversion detection unit 18 outputs a polarity inversion detection signal. In the transceiver control unit 19, when the polarity inversion detection signal is input, the information to be received reproduced by the first synchronous detection unit 16a is transmitted to the information processing apparatus.

  On the other hand, in the case of an abnormality shown in FIG. 4, a stray capacitance C ′ is further formed between the second electrode 72b of the portable electric field communication device 7 possessed by the passing person A and the passing person B. The negative polarity signal output from the second electrode 72b of the portable electric field communication device 7 possessed by the passer-by B is also first installed via the stray capacitance C ′, the passer-by A, the stray capacitance C1, and the stray capacitance C2. It is transmitted to the electrode 11a and the second installation electrode 11b.

  In this case, since the signals having the same polarity are received by the first installation electrode 11a and the second installation electrode 11b, each reception reproduced by the first synchronous detection unit 16a and the second synchronous detection unit 16b is received. The signal polarity of the power information is not reversed, and the polarity reversal detection unit 18 does not output the polarity reversal detection signal. Since the transceiver controller 19 has not received the polarity inversion detection signal, the transceiver controller 19 discards the information to be received reproduced by the first synchronous detector 16a.

  As described above, according to the present embodiment, the first installation electrode 11a and the second installation electrode 11b are arranged adjacent to each other along the traveling direction of the passer A on the side surface of the gate 3, and are opposed to each other. When a passer-by A who has a portable electric field communication device 7 that outputs a positive signal and a negative signal from the second electrode 72b and the second electrode 72b passes through the gate 3, the carrier reproducing unit 14 The carrier wave is reproduced from the signal received by the first installation electrode 11a, and the first synchronous detector 16a synchronously detects the reproduced carrier wave and the signal received by the first installation electrode 11a to reproduce the information to be received. Then, the second synchronous detector 16b synchronously detects the reproduced carrier wave and the signal received by the second installation electrode 11b and reproduces the information to be received. Then, the polarity reversal detection unit 18 collates the reproduced information to be received, detects whether the polarity is reversed, and outputs a polarity reversal detection signal if the polarity is reversed. Thereafter, the transceiver control unit 19 processes the information to be received when the polarity reversal detection signal is received as valid information, so that it is possible to reduce the false authentication of the passing person when passing through the gate.

  In the above description, the first electrode 72a has been described on the assumption that signals of different polarities are output from the first electrode 72a and the second electrode 72b of the transceiver 71 in the portable electric field communication device 7. Are connected to a circuit (not shown) for outputting a signal inside the transceiver 71 and the second electrode 72b is connected to a circuit ground (not shown) inside the transceiver 71, the first electrode 72a and the second electrode 72b It is the same that the polarities of the signals output from the electrodes 72b are different.

  The second electrode 72b connected to the circuit ground of the transceiver 71 is not connected to the circuit ground of the installation electric field communication device 1 and is not fixed at zero potential. With reference to the figure, the potential of the second electrode 72b at the time of transmission in the transceiver 71 changes with the opposite polarity to the potential of the first electrode 72a. This change is transmitted to the second installation electrode 11b and the passing person A through the stray capacitance C2 or the stray capacitance C ′.

  Therefore, even when the first electrode 72a is connected to the circuit that outputs the signal inside the transceiver 71 and the second electrode 72b is connected to the circuit ground inside the transceiver 71, the passage at the time of passing through the gate is possible due to the above-described effect. It is possible to reduce misidentification of people.

  In the embodiment shown in FIG. 1, only the first installation electrode 11 a and the second installation electrode 11 b are used. However, as shown in FIG. 5, the ground electrode 22 is further added to the installation electric field communication device 1. It can also be provided. The ground electrode 22 is disposed on the opposite side of the passage (right side in FIG. 17) so as to cover the first installation electrode 11a and the second installation electrode 11b (so as to face each installation electrode). It is connected to the circuit ground (not shown) of the electric field communication apparatus 1 for use. By using the ground electrode 22, an electric field from the opposite side is not received at the time of reception, and an electric field is not transmitted to the opposite side at the time of transmission, so that erroneous authentication can be prevented more reliably. In FIG. 5, one ground electrode is used. However, as shown in FIG. 6, two ground electrodes 22 are paired with each of the first installation electrode 11a and the second installation electrode 11b. May be used.

  Next, a method for installing the first installation electrode 11a and the second installation electrode 11b will be described. In the above embodiment, the gate 3 is installed only on one side of the passageway through which the passer passes, and the first installation electrode 11a and the second installation electrode 11b are arranged adjacent to the side surface of the one gate 3, Of the pair of installation electrodes, one may be arranged so as not to face the left front of the passage and the other to the right rear. Specifically, as shown in FIG. 7, the gates 3 a and 3 b are installed so as to face each other across the passage, and the first installed electrode 11 a is set to one polarity output from the portable electric field communication device 7. The second installation electrode 11b is arranged in front of the side surface of the gate 3b so as to receive the signal of the other polarity.

  In FIG. 7, the second installation electrode 11 b is directly connected to the installation electric field communication device 1. However, as shown in FIG. 8, a part of the function of the installation electric field communication device 1 is used as the remote signal processing unit 23. The remote signal processing unit 18 is separated from the installation electric field communication device 1 and connected between the second installation electrode 11b and the installation electric field communication device 1 ′ after the function separation, and the remote signal processing unit 18 is gated. You may install in 3b. A configuration example in this case is shown in FIGS.

  FIG. 9 is a diagram illustrating a functional block configuration of the electric field communication device for installation after the function separation. The installation electric field communication apparatus 1 ′ after the function separation is different from the installation electric field communication apparatus 1 shown in FIG. 1 in that the second transmission / reception changeover switch 12b, the second amplification / filter unit 13b, and the second synchronous detection unit 16b. And are separated.

  FIG. 10 is a diagram illustrating a functional block configuration of the remote signal processing unit. The remote signal processing unit 23 includes a second transmission / reception selector switch 12b, a second amplification / filter unit 13b, a second synchronous detection unit 16b, and a second transmission / reception switch 12b separated from the installation electric field communication device 1 shown in FIG. And an output unit 21b that is connected to the transmission terminal c2 of the transmission / reception selector switch 12b and outputs the signal modulated by the modulation unit 20 from the second installation electrode 11b.

  At the time of reception, in the installation electric field communication device 1 ′, the electrode terminal a1 and the reception terminal b1 of the first transmission / reception selector switch 12a are connected, and the noise component of the signal from the first installation electrode 11a is the first. The signal is removed by the amplification / filter unit 13a and only the signal component is amplified. Then, a carrier wave recovery unit 14 generates a recovered carrier wave from the output signal of the first amplification / filter unit 13a, and outputs it to the first synchronous detection unit 16a and the second synchronous detection unit 16b of the remote signal processing unit 23. Is done. The first synchronous detection unit 16 a synchronously detects the output signal of the first amplification / filter unit 13 a and the regenerated carrier wave from the carrier wave reproduction unit 14 and outputs it to the polarity inversion detection unit 18.

  In the remote signal processing unit 23, at the time of reception, the electrode terminal a2 and the reception terminal b2 of the second transmission / reception selector switch 12b are connected, and the noise component of the signal from the second installation electrode 11b is second amplified and amplified. The signal is removed by the filter unit 13b and only the signal component is amplified. The second synchronous detector 16b synchronously detects the output signal of the second amplification / filter unit 13b and the regenerated carrier wave from the installation electric field communication device 1 ′, and detects the polarity reversal of the installation electric field communication device 1 ′. To the unit 18.

  The polarity inversion detection unit 18 receives the output signal of the first synchronous detection unit 16a and the output signal of the second synchronous detection unit 16b, and reverses the polarity when it is detected that the polarities of both signals are inverted. A detection signal is output. Thereafter, the transceiver control unit 19 transmits the received data to the upper information processing apparatus only when the polarity inversion detection signal is input. When the polarities of the signals received by the first installation electrode 11a and the second installation electrode 11b are reversed, the signals detected by the first synchronous detection unit 16a and the second synchronous detection unit 16b The polarities are also reversed. Further, when the polarities of the signals received by the first installation electrode 11a and the second installation electrode 11b are the same, the polarities of the signals synchronously detected by the first synchronous detection unit 16a and the second synchronous detection unit 16b Is the same.

  As shown in FIG. 3, when the passer-by A who has the portable electric field communication device 7 and should be authenticated passes through the gate, the first installation electrode 11a and the second installation electrode 11b have polarities. Since different signals are input, the received data is transmitted to a higher-level information processing apparatus and can be authenticated. On the other hand, when receiving a signal that is erroneously induced from another passer-by B as shown in FIG. 4, signals having the same polarity are received by the first installation electrode 11a and the second installation electrode 11b. Since the data is input, the received data is not transmitted to the upper information processing apparatus. That is, even if it is a case where it is a structure shown in FIGS. 8-10, the misidentification of the passing person at the time of gate passage can be reduced.

  Moreover, as shown in FIG. 11, it is also possible to use two pairs of electrodes, and arrange one pair on the left side of the passage and the other pair on the right side of the passage. Since a pair of installation electrodes are arranged on the left and right sides of the passage, even if one pair of installation electrodes fails to receive a signal, the other pair of installation electrodes receives the signal. The certainty can be improved. In addition, it is possible to suppress a variation in the communication distance from the portable electric field communication device 7 to each installation electrode and improve the recognition rate.

DESCRIPTION OF SYMBOLS 1 ... Installation electric field communication apparatus 3, 3a, 3b ... Gate 7, 7a, 7b ... Portable electric field communication apparatus 11 ... Installation electrode 11a ... 1st installation electrode 11b ... 2nd installation electrode 12a ... 1st transmission / reception switching Switch 12b... Second transmission / reception changeover switch 13a... First amplification / filter section 13b... Second amplification / filter section 14.
15: Carrier detection unit 16a: First synchronous detection unit (first synchronous detection means)
16b ... 2nd synchronous detection part (2nd synchronous detection means)
17 ... Waveform shaping unit 18 ... Polarity inversion detection unit (polarity inversion detection means)
19 ... Transceiver control section (control means)
DESCRIPTION OF SYMBOLS 20 ... Modulation part 21 ... Output part 22 ... Ground electrode 23 ... Remote processing communication part 71 ... Transceiver 72a ... 1st electrode 72b ... 2nd electrode A, B ... Passer C, C ', C1, C2 ... Floating capacitance W1, W1a, W1b, W2 ... Transmission path S ... Control signal

Claims (5)

In an electric field communication apparatus for installation used for a gate through which a mobile body carrying a portable electric field communication apparatus that modulates signals of different polarities based on information to be transmitted and outputs the electric fields from different electrodes, respectively,
A first installation electrode and a second installation electrode installed on the gate so as to receive a signal output from the portable electric field communication device through the mobile body by an electric field;
Carrier wave reproducing means for reproducing a carrier wave from a signal received by the first installation electrode;
First synchronous detection means for synchronously detecting the reproduced carrier wave reproduced and the signal received by the first installation electrode to reproduce the information to be received;
Second synchronous detection means for synchronously detecting the reproduced carrier wave and the signal received by the second installation electrode and reproducing the information to be received;
Each received information reproduced by the first synchronous detection means and the second synchronous detection means is collated, and it is detected whether or not the polarity is inverted. Polarity inversion detection means for outputting a detection signal;
Control means for processing the information to be received as valid information when the polarity reversal detection signal is received;
An electric field communication device for installation characterized by comprising: The first installation electrode and the second installation electrode are:
2. The device according to claim 1, wherein when the passer passes the gate, the signal is arranged on a side surface of the gate so as to receive the signals having different polarities output from the portable electric field communication device. The electric field communication apparatus for installation as described. The gate has two side surfaces facing each other across the passage,
The first installation electrode is disposed on one side surface, and the second installation electrode is disposed on the other side so as not to face the first installation electrode. Electric field communication device for installation. The second synchronous detection means is disposed in the gate on the side where the second installation electrode is disposed,
4. The installation according to claim 3, further comprising amplification / filter means for removing a noise component of a signal received by the second installation electrode and amplifying the signal component in front of the second synchronous detection means. Electric field communication device. The gate has two side surfaces facing each other across the passage,
The first installation electrode and the second installation electrode are:
The installation electric field communication device according to claim 2, wherein the electric field communication device is installed on the two side surfaces.

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