JP2006245656A - Wireless communication apparatus, wireless communication method, and non-contact ic card reader/writer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus capable of preventing degradation of its communication performance. <P>SOLUTION: The wireless communication apparatus capable of making communication with a plurality of kinds of wireless communication media whose resonance frequencies differ from each other includes: a transmission means employing a first resonance frequency tuned to and resonated with the resonance frequencies of the wireless communication media and for transmitting a signal to the wireless communication media; and a reception means employing a second resonance frequency not resonated with the resonance frequencies of the wireless communication media in the resonance state of the transmission means and for receiving the signal from the wireless communication media. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication apparatus, a wireless communication method, and a non-contact IC for transmitting information to and receiving information from a wireless communication medium such as a non-contact IC card and a mobile phone. The present invention relates to a card reader / writer device.

  In recent years, non-contact IC cards that can be used in a non-contact manner have been spreading from the viewpoint of information safety and portability, and various proposals for non-contact information transmission / reception using such non-contact IC cards. (See Patent Document 1).

  For example, a reader / writer provided with one loop antenna common to transmission and reception is known. The resonance frequency of such a transmission / reception common loop antenna is uniquely determined by the capacitance (circuit constant) of a capacitor connected to the transmission / reception common loop antenna.

  Also known is a reader / writer equipped with two independent loop antennas for transmission and reception. The resonance frequency of such a transmission loop antenna is determined by the capacitance of the capacitor connected to the transmission loop antenna, and the resonance frequency of the reception loop antenna is determined by the capacitance of the capacitor connected to the reception loop antenna. Determined by capacity.

  For the purpose of ensuring stable communication characteristics with IC cards and a wide range of communication areas (good communication characteristics within an assumed predetermined communication range) by adjusting the antenna resonance frequency for both of the above two reader / writers. Yes.

It is possible to respond to fixed IC resonance frequency for specific IC card such as transportation system for station service or electronic money system or IC card which has different resonance frequency on the IC card side (several tens of kHz). Thus, it was possible to obtain good communication characteristics.
Japanese Patent No. 3579899 (Japanese Patent Laid-Open No. 8-194785)

  For specific IC cards or IC cards that have different resonance frequencies in the small range (about several tens of kHz), it is possible to deal with fixed antenna resonance frequencies and obtain good communication characteristics. there were. However, for IC cards with greatly different antenna resonance frequencies (several hundred kHz to several MHz), the antenna resonance frequency on the reader / writer side is fixed, and the characteristics are better than the IC card a having the resonance frequency fa. Even if the antenna circuit constant, resonance frequency, etc. of the reader / writer are adjusted, performance (good communication characteristics) cannot be obtained for an IC card b having a different resonance frequency fb. On the other hand, when the reader / writer side is adjusted, it is difficult to set such that both cards obtain good characteristics, such as the communication characteristics of the IC card a being deteriorated.

  The cause is that both the transmitting and receiving loop antennas are resonant antennas and have a resonance frequency, so that a card antenna having another resonance frequency causes mutual induction with the loop antenna of the reader / writer and causes strong coupling. This is because there is a region where the received signal from the card is suppressed by the carrier and becomes a voltage level that cannot be demodulated. As a result, an incommunicable area is generated within a predetermined communication range, and communication performance is degraded.

  An object of the present invention is to solve the above-described problems, and provides a wireless communication device, a wireless communication method, and a non-contact type IC card reader / writer device that can prevent a decrease in communication performance. There is.

  The wireless communication apparatus and wireless communication method of the present invention are configured as follows.

  (1) The present invention is a wireless communication apparatus that enables communication with a plurality of types of wireless communication media having different resonance frequencies, and the resonance frequency of the wireless communication medium is set within a predetermined communication range with the wireless communication medium. A transmission means for transmitting a signal to the wireless communication medium having a first resonance frequency that tunes and resonates with the wireless communication medium, and a predetermined communication range between the wireless communication medium and the resonance frequency of the wireless communication medium; And a receiving means for receiving a signal from the wireless communication medium. The wireless communication apparatus has a second resonance frequency that is non-resonant.

  (2) The present invention is a wireless communication method that enables communication with a plurality of types of wireless communication media having different resonance frequencies, and the predetermined wireless communication medium has a predetermined communication range with the wireless communication medium. And a predetermined resonance frequency that resonates by tuning a resonance frequency of a transmission / reception antenna that transmits a signal to and receives a signal from the predetermined wireless communication medium with respect to each resonance frequency of each of the plurality of types of wireless communication media. Average resonance frequency), discriminate the predetermined radio communication medium based on a signal received from the predetermined radio communication medium by the transmission / reception antenna, and control the resonance frequency of the transmission / reception antenna based on the discrimination result A wireless communication method characterized by the above.

  (3) The present invention is a non-contact type IC card reader / writer device that performs data transmission and reception with an IC card by wireless communication and performs predetermined data processing, and the IC is in a predetermined communication range with the IC card. The first resonance frequency that resonates in synchronization with the resonance frequency of the card, and the transmission means for transmitting a signal to the IC card, and the resonance frequency of the IC card within a predetermined communication range with the IC card A receiving means for receiving a signal from the IC card, and a control for transmitting and receiving data to and from the IC card via the transmitting means and the receiving means to perform predetermined data processing. A non-contact type IC card reader / writer device.

  According to the present invention, it is possible to provide a wireless communication device, a wireless communication method, and a non-contact type IC card reader / writer device that can prevent a decrease in communication performance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of a reader / writer according to an example of a non-contact IC card reader / writer device and a wireless communication device of the present invention. As shown in FIG. 1, the reader / writer 1 performs wireless communication with the IC card 2, and includes a control unit 11, a wireless circuit 12, and an antenna unit 13. Further, the radio circuit 12 includes a modulation circuit 121 and a demodulation circuit 122.

  FIG. 2 is a diagram showing a first example of the configuration of the radio circuit 12 and the antenna unit 13 of the reader / writer shown in FIG. As shown in FIG. 2, the antenna unit 13 includes a transmission antenna 131 constituted by a loop coil having a resonance frequency f1 and a reception antenna 132 constituted by a loop coil having a resonance frequency f2 (resonance frequency f1 << Resonance frequency f2). Further, the radio circuit 12 includes a capacitor C connected to the antenna end of the transmission antenna 131. The resonance frequency f1 of the loop coil of the transmission antenna 131 is set by the value of the capacitor C. Capacitor C may be a variable capacity capacitor or a fixed capacity capacitor. Note that a capacitor is not connected to the antenna end of the receiving antenna 132. Thereby, the resonance frequency f2 of the loop coil of the receiving antenna 132 (a very large value with respect to the resonance frequency f1, for example, a value of 10 times or more with respect to the resonance frequency f1) is set.

  The reader / writer 1 receives various commands from the host device 3. The control unit 11 of the reader / writer 1 generates an IC card command (transmission data) based on the received command. The modulation circuit 121 of the reader / writer 1 modulates an IC card command (transmission data) according to a predetermined modulation method. The transmission antenna 131 generates a magnetic field by a loop coil having a resonance frequency f1. At this time, when a condition for causing mutual induction between the loop coil of the resonance frequency f1 of the transmission antenna 131 and the loop coil of the antenna 22 of the IC card (wireless communication medium) 2 is satisfied (the IC card 2 is in a predetermined communication range of the reader / writer 1). The signal transmitted from the transmission antenna 131 is received by the antenna 22 of the wireless card 2 (within the range in which communication effectiveness is assumed by design).

  The control unit 21 of the IC card 2 outputs a response to the reception of the command from the reader / writer 1. That is, a response is output from the antenna 22 of the IC card 2. The receiving antenna 132 of the reader / writer 1 receives this response by the loop coil having the resonance frequency f2. The demodulation circuit 122 demodulates the received signal in accordance with a predetermined demodulation method, and transmits the demodulated reception data to the control unit 11. The control unit 11 makes various determinations based on the received data, and transmits the determination results to the higher-level device 3.

  As described above, by configuring the transmission antenna 131 and the reception antenna 132 independently, in a state where the transmission antenna 131 tunes and resonates with respect to the resonance frequency of the IC card 2 as the IC card 2 approaches ( When the IC card 2 is in the communicable range of the reader / writer 1), the receiving antenna 132 becomes non-resonant with respect to the resonance frequency of the IC card 2 (does not cause strong coupling). As a result, it is possible to sufficiently avoid that the impedance increases due to strong coupling and the received signal voltage level is suppressed by the carrier and cannot be demodulated. Note that a capacitor is actually connected to the receiving antenna 132 for matching. For example, if the resonance frequency f1 is about 13.56 MHz, the resonance frequency f2 is several hundred MHz or more.

  FIG. 3 is a diagram showing the relationship between the resonance frequency f1 of the transmission antenna 131 and the resonance frequency f2 of the reception antenna 132 of the reader / writer 1, and the resonance frequency fa of the target IC card a and the resonance frequency fb of the IC card b. is there. As described above, the resonance frequency f2 is set to several hundred MHz or more with respect to the resonance frequency f1 of about 13.56 MHz. As a result, assuming that the resonance frequency fa of the target IC card a is about 16 MHz to 17.5 MHz and the resonance frequency fb of the IC card b is about 18 MHz to 19 MHz, the receiving antenna 132 is connected to the IC cards a and b. Non-resonant.

  Next, an arrangement example of the transmission antenna 131 and the reception antenna 132 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the loop coil of the reception antenna 132 is disposed inside (inner circumference) of the loop coil of the transmission antenna 131. In other words, the resonance capacitors C are connected to both ends of the loop coil of the transmission antenna 131 disposed outside (outer circumference) of the loop coil of the reception antenna 132. Alternatively, as shown in FIG. 5, the loop coil of the reception antenna 132 is arranged outside (outer circumference) of the loop coil of the transmission antenna 131. That is, a resonance capacitor C is connected to both ends of the loop coil of the transmission antenna 131 arranged on the inner side (inner circumference) of the loop coil of the reception antenna 132.

  FIG. 6 is a diagram illustrating a second example of the configuration of the wireless circuit 12 and the antenna unit 13 of the reader / writer illustrated in FIG. As shown in FIG. 6, the antenna unit 13 includes a transmission / reception shared antenna 133 configured by a loop coil. The radio circuit 12 includes a capacitor C and a switching circuit SW. A capacitor C is connected to one end of the transmission / reception shared antenna 133, and a switching circuit SW is connected to the other end of the transmission / reception shared antenna 133. Capacitor C may be a variable capacity capacitor or a fixed capacity capacitor.

  The switching circuit SW switches between opening and closing of the circuit based on the SW control signal from the control unit 11. Thereby, the capacitor C is connected to the antenna end of the transmission / reception shared antenna 133, or the capacitor C is disconnected from the antenna end of the transmission / reception shared antenna 133. When the capacitor C is connected to the antenna end of the transmission / reception shared antenna 133 by the switching circuit SW, it is constituted by the resonance frequency f1 of the loop coil of the shared transmission / reception antenna 133. Further, when the capacitor C is disconnected from the antenna end of the transmission / reception shared antenna 133 by the switching circuit SW, the shared transmission / reception antenna 133 is constituted by a loop coil having a resonance frequency f2 (resonance frequency f1 << resonance frequency f2).

  As described above, even when the transmission / reception shared antenna 133 in which the transmission antenna and the reception antenna are shared is adopted, by connecting the capacitor C to the antenna end of the transmission / reception shared antenna 133 during the data transmission period, the transmission / reception shared antenna 133 The loop coil 133 has a resonance frequency f1 that resonates in synchronization with the resonance frequency of the IC card 2 as the IC card 2 approaches. Further, by separating the capacitor C from the antenna end of the transmission / reception shared antenna 133 during the data reception period, the loop coil of the shared transmission / reception antenna 133 becomes non-resonant with respect to the resonance frequency of the IC card 2 (does not cause strong coupling). ) It has a resonance frequency f2.

  Next, control of the switching circuit SW by the SW control signal will be described with reference to FIG.

  The control unit 11 outputs (ON) the SW control signal before the transmission data transmission starts (immediately before), and stops (OFF) the SW control signal after the transmission data transmission (after completion). Thereby, during transmission of transmission data, the capacitor C is connected to the antenna end of the transmission / reception shared antenna 133 by the switching circuit SW, and the loop coil of the transmission / reception shared antenna 133 has the resonance frequency f1. That is, when the IC card 2 enters the communicable area of the reader / writer 1, the loop coil of the transmission / reception shared antenna 133 resonates with the loop coil of the antenna 22 of the IC card 2.

  After transmission of transmission data is completed, reception data reception wait state is entered. The control unit 11 continues to stop (OFF) the SW control signal until reception of the received data is completed. As a result, during the reception waiting state of reception data and reception of reception data, the capacitor C is disconnected from the antenna end of the transmission / reception shared antenna 133 by the switching circuit SW, and the loop coil of the transmission / reception shared antenna 133 has the resonance frequency f2. That is, even if the IC card 2 enters the communicable area of the reader / writer 1, the loop coil of the transmission / reception shared antenna 133 is in a non-resonant state with respect to the loop coil of the antenna 22 of the IC card 2.

  When the control unit 11 detects the completion of reception of the received data and determines that transmission of the next transmission data is necessary, the control unit 11 outputs (ON) the SW control signal before starting transmission of the next transmission data (immediately before). After the transmission of (after completion), the SW control signal is stopped (OFF). If the control unit 11 cannot detect completion of reception of received data, the control unit 11 continues to wait for reception of received data until it is determined that transmission of transmission data is necessary. That is, the SW control signal is continuously stopped (OFF).

  By repeating the above control, it is possible to switch resonance / non-resonance for transmission / reception with respect to the IC card 2 by the transmission / reception shared antenna 133 shared for transmission and reception.

  FIG. 8 is a diagram showing a third example of the configuration of the radio circuit 12 and the antenna unit 13 of the reader / writer shown in FIG. As illustrated in FIG. 8, the antenna unit 13 includes a transmission / reception shared antenna 133 configured by a loop coil. The wireless circuit 12 includes n capacitors C1, C2,..., Cn, and n switching circuits SW1, SW2,. Capacitors C1, C2,..., Cn may be capacitors with variable capacitance, or capacitors with fixed capacitance.

  A capacitor C1 is connected to one end of the transmission / reception shared antenna 133, and a switching circuit SW1 is connected to the other end of the transmission / reception shared antenna 133. The switching circuit SW1 switches between opening and closing of the circuit based on the SW1 control signal from the control unit 11. Thereby, the capacitor C1 is connected to the antenna end of the transmission / reception shared antenna 133, or the capacitor C1 is disconnected from the antenna end of the transmission / reception shared antenna 133.

  The capacitor C2 is connected to one end of the transmission / reception shared antenna 133, and the switching circuit SW2 is connected to the other end of the transmission / reception shared antenna 133. The switching circuit SW2 switches between opening and closing of the circuit based on the SW2 control signal from the control unit 11. Thereby, the capacitor C2 is connected to the antenna end of the transmission / reception shared antenna 133, or the capacitor C2 is disconnected from the antenna end of the transmission / reception shared antenna 133.

  Similarly, a capacitor Cn is connected to one end of the transmission / reception shared antenna 133, and a switching circuit SWn is connected to the other end of the transmission / reception shared antenna 133. The switching circuit SWn switches between opening and closing of the circuit based on the SWn control signal from the control unit 11. Thereby, the capacitor Cn is connected to the antenna end of the transmission / reception shared antenna 133, or the capacitor Cn is disconnected from the antenna end of the transmission / reception shared antenna 133.

  As an example, both the SW1 control signal and the SWn control signal are output (ON), and the SW2 control signal is stopped (OFF). Thereby, the capacitors C1 and Cn are connected to the antenna end of the transmission / reception shared antenna 133, and the resonance frequency of the loop coil of the shared transmission / reception antenna 133 is determined by the capacitors C1 and Cn.

  For example, several control signals among the SW1 control signal, SW2 control signal,..., SWn control signal are output (ON) from the start of transmission of transmission data to the completion of transmission. In addition, during the period from reception waiting for reception data to completion of reception of reception data, all outputs of the SW1 control signal, SW2 control signal,..., SWn control signal are stopped (OFF). This makes it possible to switch to a resonant antenna that resonates with the IC card 2 during transmission and to a non-resonant antenna that does not resonate with the IC card 2 during reception. It is also possible to use a resonance antenna during reception by combining the output (ON) and stop (OFF) of the SW1 control signal, SW2 control signal,..., SWn control signal.

  FIG. 9 is a flowchart for explaining an example of switching control of a plurality of switching circuits of the reader / writer shown in FIG.

  The reader / writer 1 (control unit 11) sets the output of each control signal of the SW1 control signal, SW2 control signal,..., SWn control signal to an initial value (ST1). Accordingly, the resonance frequency of the transmission / reception shared antenna 133 is an average resonance frequency (not necessarily a strict average value) that resonates in synchronization with each resonance frequency of a plurality of types of IC cards targeted by the reader / writer 1. The frequency may be a frequency that is tuned to the resonance frequency of the IC card having the highest utilization rate, and is essentially the initial predetermined value. Subsequently, the reader / writer 1 transmits a polling command to the IC card in order to acquire the unique number of the IC card (ST2).

  When the reader / writer 1 receives a response from the IC card in response to the polling command (ST3, YES), the IC card unique number included in the received data is detected (ST5), and the IC card is based on the IC card unique number. And the like are discriminated (ST6). When the reader / writer 1 does not receive a response from the IC card to the polling command (ST3, NO) and times out (ST4, YES), it again transmits the polling command to the IC card (ST2).

  The reader / writer 1 (or the host device 3) stores data of optimum resonance frequency for each type of IC card in advance. That is, the reader / writer 1 can read out the optimum resonance frequency for the IC card based on the determination result of the type of the IC card. The reader / writer 1 controls the output of the SW1 control signal to the SWn control signal (controls ON / OFF) (can be ON of a single SW or a combination of a plurality of SWs). The resonance frequency of the loop coil is set to the optimum resonance frequency for the IC card (ST7).

  The setting of the resonance frequency may be the same for transmission and reception, or may be different. When the resonance frequency is set to be the same for transmission and reception, once it is set, it is not necessary to reset it until communication with the IC card is completed. When the resonance frequency is set differently for transmission and reception, it is reset every transmission period and reception period until communication with the IC card is completed.

  The reader / writer 1 sets the resonance frequency of the loop coil of the transmission / reception shared antenna 133 to the optimum resonance frequency for transmission for the IC card (ST7), and then transmits a command to the IC card (ST8). When the transmission of the command to the IC card is completed, the reader / writer 1 sets the resonance frequency of the loop coil of the transmission / reception shared antenna 133 to the reception resonance frequency optimum for the IC card (ST9). When the reader / writer 1 receives a signal from the IC card (ST10, YES), it processes the received signal (ST12). The reader / writer 1 repeats the above setting until the communication with the IC card is completed. When the communication is completed (ST13, YES), the reader / writer 1 prepares for the processing of the next card (ST14). That is, the reader / writer 1 (control unit 11) sets the output of each control signal of the SW1 control signal, SW2 control signal,..., SWn control signal to an initial value (ST1).

  Next, with reference to FIG. 10 to FIG. 13, the problem of the generation of the communication incompetent area due to the strong coupling and the exclusion of the incommunicable area which is the effect of the present invention will be described. 10 and 11 are diagrams illustrating a schematic configuration of a reader / writer that may cause an incommunicable region due to strong coupling. FIG. 12 is a diagram illustrating an incommunicable region that occurs due to strong coupling. FIG. 13 is a diagram for explaining exclusion of an incommunicable area, which is an effect of the present invention.

  As shown in FIG. 10, a reader / writer equipped with one loop antenna common to transmission and reception is assumed. The resonance frequency of such a transmission / reception common loop antenna is uniquely determined by the capacitance of the capacitor connected to the transmission / reception common loop antenna.

  As shown in FIG. 11, a reader / writer having two independent loop antennas for transmission and reception is assumed. The resonance frequency of such a transmission loop antenna is determined by the capacitance of the capacitor connected to the transmission loop antenna, and the resonance frequency of the reception loop antenna is determined by the capacitance of the capacitor connected to the reception loop antenna. Determined by capacity.

  The reader / writer shown in FIG. 10 and FIG. 11 can cope with a specific IC card or an IC card that is different in a range where the resonance frequency on the IC card side is small (about several tens of kHz) with a fixed antenna resonance frequency. It is possible to obtain good communication characteristics to some extent. However, since the antenna resonance frequency on the reader / writer side is fixed for an IC card having greatly different antenna resonance frequencies (several hundred kHz to several MHz), the characteristics are better than the IC card a having the resonance frequency fa. Even if the antenna circuit constant of the reader / writer, the resonance frequency, etc. are adjusted, the performance cannot be obtained for the IC card b having another resonance frequency fb. When adjusted, it is difficult to make settings so that both cards obtain good characteristics, such as the communication characteristics of the IC card a falling.

  The cause is that both the transmitting and receiving loop antennas are resonant antennas and have a resonance frequency, so that a card antenna having another resonance frequency causes mutual induction with the loop antenna of the reader / writer and causes strong coupling. This is because there is a region where the received signal from the card is suppressed by the carrier and becomes a voltage level that cannot be demodulated. As a result, an incommunicable area (see FIG. 12) occurs in the communication range, and the communication performance deteriorates.

  By setting the value of the resonance frequency f2 of the loop coil of the reception antenna 132 to 10 times or more than the value of the resonance frequency f1 of the loop coil of the transmission antenna 131 of the reader / writer 2 of the present invention, The value of the resonance frequency f1 of the loop coil during the signal transmission period by the transmission / reception shared antenna 133 of the reader / writer 2 is set to 10 times or more the value of the resonance frequency f2 of the loop coil during the signal reception period by the shared transmission / reception antenna 133. As a result, as shown in FIG. 13, it is possible to exclude (push out) the incommunicable area from the communicable area.

  The effects of the reader / writer according to the present invention will be summarized below.

  Coupling occurs when coils that resonate with each other approach each other, and when the coupling becomes stronger, the impedance increases, the reception voltage level of the received signal from the IC card approaches 0 V, and the IC card is in the communicable area on the reader / writer antenna. Nevertheless, an incommunicable area where demodulation cannot be performed or reception accuracy is reduced occurs (see FIG. 12).

  Therefore, by separating the loop antenna used for transmission and the loop antenna used for reception separately from each other, strong coupling does not occur between the reception loop antenna having no resonance frequency and the IC card antenna. Like that.

  As a result, the situation where the impedance when the strong coupling occurs becomes difficult to occur, and it can be avoided that the received signal from the IC card is at a level where it cannot be demodulated. It is difficult to generate a null phenomenon), and it is possible to realize good communication characteristics without generating an incommunicable region that cannot be demodulated.

  Also, when there are several types of IC cards with greatly different antenna resonance frequencies, it is difficult to ensure good communication characteristics for all the cards at the set resonance frequency when using a resonance antenna for reception by the reader / writer. become. It is conceivable that strong coupling is generated with the remaining several types of IC cards even though strong coupling is not generated with some types of IC cards.

  Therefore, by using a non-resonant antenna as the receiving antenna on the reader / writer side, an antenna configuration that does not cause strong coupling with any IC card is obtained.

  As a result, it is possible to realize communication characteristics that do not cause a signal that cannot be demodulated as described above, and a communication incapable area does not occur, and that have good communication characteristics for a plurality of IC cards having greatly different antenna resonance frequencies. Can be obtained.

  As opposed to the above, when switching between transmission and reception using a common antenna, a switching element is used and switching between transmission and reception makes it a resonant antenna at the time of transmission and a non-resonant antenna at the time of reception. Can be switched. By providing one common antenna, the same effect as described above can be obtained.

  Further, as shown in FIG. 8, by using a plurality of switching elements, in addition to switching transmission to resonance and reception to non-resonance as described above, both transmission and reception are switched to an antenna having a plurality of resonance frequencies. This also makes it possible to use an antenna set to an optimum resonance frequency for a specific IC card.

  An antenna is used for both transmission and reception. In addition to the above, a plurality of changeover switches are provided, and an optimum combination of changeover switches for each IC card used in the system is determined in advance. Keep the settings optimal when you start. Thereby, it is possible to obtain optimum communication characteristics according to the IC card.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

It is a block diagram which shows schematic structure of the reader / writer which concerns on an example of the radio | wireless communication apparatus of this invention. It is a figure which shows the 1st example of a structure of the radio | wireless circuit and antenna part of the reader / writer shown in FIG. It is a figure which shows the relationship between the resonance frequency f1 and resonance frequency f2 of a reader / writer, and the resonance frequency fa and resonance frequency fb of the IC card used as a target. It is a figure which shows the 1st example of arrangement | positioning of a transmission antenna and a receiving antenna. It is a figure which shows the 2nd example of arrangement | positioning of a transmission antenna and a receiving antenna. It is a figure which shows the 2nd example of a structure of the radio | wireless circuit and antenna part of the reader / writer shown in FIG. The control of the switching circuit by the SW control signal will be described. It is a figure which shows the 3rd example of a structure of the radio | wireless circuit and antenna part of the reader / writer shown in FIG. It is a flowchart for demonstrating an example of switching control of the some switching circuit of the reader / writer shown in FIG. It is a figure which shows the 1st example of the reader / writer which may generate a communication impossible area. It is a figure which shows the 2nd example of the reader / writer which may generate a communication impossible area. It is a figure which shows the communication impossible area | region which generate | occur | produces by strong coupling. It is a figure for demonstrating exclusion of the communication impossible area | region which is an effect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reader / writer, 2 ... IC card, 3 ... High-order apparatus, 11 ... Control part, 12 ... Radio circuit, 13 ... Antenna part, 121 ... Modulation circuit, 122 ... Demodulation circuit, 131 ... Transmission antenna, 132 ... Reception antenna, 133 ... Transmitting and receiving antenna

Claims (15)

A wireless communication device that enables communication with a plurality of types of wireless communication media having different resonance frequencies,
Transmitting means for transmitting a signal to the wireless communication medium having a first resonance frequency that resonates in resonance with the resonance frequency of the wireless communication medium within a predetermined communication range with the wireless communication medium;
Receiving means for receiving a signal from the wireless communication medium having a second resonance frequency that is non-resonant with the resonance frequency of the wireless communication medium within a predetermined communication range with the wireless communication medium;
A wireless communication apparatus comprising:   The wireless communication apparatus according to claim 1, wherein the second resonance frequency is a frequency that is ten times or more of the first resonance frequency. The transmission means includes
A modulation circuit for modulating transmission data;
A transmission antenna configured by a loop coil that transmits a signal modulated by the modulation circuit to a wireless communication medium;
A capacitor for obtaining tuning with each resonance frequency of each wireless communication medium;
With
The receiving means includes
A receiving antenna constituted by a loop coil for receiving a signal from a wireless communication medium;
A demodulation circuit for demodulating a signal received by the receiving antenna;
The wireless communication apparatus according to claim 1, further comprising:   The radio communication apparatus according to claim 3, wherein a loop coil of the reception antenna is arranged on an inner periphery of the loop coil of the transmission antenna.   The radio communication apparatus according to claim 3, wherein a loop coil of the reception antenna is disposed on an outer periphery of the loop coil of the transmission antenna. A wireless communication device that enables communication with a plurality of types of wireless communication media having different resonance frequencies,
A transmission / reception means for transmitting a signal to the wireless communication medium and receiving a signal from the wireless communication medium in a predetermined communication range with the wireless communication medium;
In a period in which a signal is transmitted to the wireless communication medium by the transmission / reception means, the resonance frequency of the transmission / reception means is controlled to a first resonance frequency that resonates in synchronization with the resonance frequency of the wireless communication medium, Control means for controlling the resonance frequency of the transmitting / receiving means to a second resonance frequency that is non-resonant with respect to the resonance frequency of the wireless communication medium during a period of receiving a signal from the wireless communication medium by
A wireless communication apparatus comprising:   The wireless communication apparatus according to claim 6, wherein the second resonance frequency is a frequency that is 10 times or more of the first resonance frequency. The transmitting / receiving means includes
A modulation circuit for modulating transmission data;
A transmission / reception antenna configured by a loop coil for transmitting a signal modulated by the modulation circuit to a wireless communication medium and receiving a signal from the wireless communication medium;
A demodulation circuit for demodulating a signal received by the transmission / reception antenna;
With
The control means includes
A capacitor to obtain tuning with each resonance frequency of each wireless communication medium;
A switching circuit for connecting a capacitor to the transmission / reception antenna in a transmission period of the signal by the transmission / reception antenna, and disconnecting the capacitor from the transmission / reception antenna in a reception period of the signal by the transmission / reception antenna;
The wireless communication apparatus according to claim 6, further comprising:   9. The wireless communication apparatus according to claim 8, wherein a plurality of capacitors are connected to the transmission / reception antenna, and a plurality of switching circuits are provided for each of the plurality of capacitors. A wireless communication device that enables communication with a plurality of types of wireless communication media having different resonance frequencies,
Transmitting and receiving means for transmitting a signal to a predetermined wireless communication medium and receiving a signal from the predetermined wireless communication medium;
The resonance frequency of the transmission / reception means is controlled to a predetermined resonance frequency that resonates in synchronization with each resonance frequency of the plurality of types of wireless communication media, and the signal received from the predetermined wireless communication medium by the transmission / reception means Control means for determining the predetermined wireless communication medium based on the determination result, and controlling the resonance frequency of the transmission and reception means based on the determination result;
A wireless communication apparatus comprising:   The control means is configured to transmit the transmission / reception means based on a determination result in a period in which the transmission / reception means transmits a signal to the predetermined wireless communication medium and a period in which the transmission / reception means receives a signal from the predetermined wireless communication medium. The wireless communication apparatus according to claim 10, wherein the resonance frequency is controlled to be switched. The transmitting / receiving means includes
A modulation circuit for modulating transmission data;
A transmission / reception antenna configured by a loop coil that transmits a signal modulated by the modulation circuit to the predetermined wireless communication medium and receives a signal from the predetermined wireless communication medium;
A demodulation circuit for demodulating a signal received by the transmission / reception antenna;
With
The control means includes
A plurality of capacitors for obtaining tuning with each resonance frequency of each of the plurality of types of wireless communication media;
A switching circuit for connecting or disconnecting the transmission / reception antenna and each capacitor;
The wireless communication apparatus according to claim 10, further comprising: A wireless communication method enabling communication with a plurality of types of wireless communication media having different resonance frequencies,
Each of the plurality of types of wireless communication has a resonance frequency of a transmission / reception antenna that transmits a signal to the predetermined wireless communication medium and receives a signal from the predetermined wireless communication medium within a predetermined communication range with the wireless communication medium. Control to a predetermined resonance frequency that resonates in synchronization with each resonance frequency of the medium,
Determining the predetermined wireless communication medium based on a signal received from the predetermined wireless communication medium by the transmission / reception antenna;
Controlling the resonant frequency of the transmitting / receiving antenna based on the determination result;
A wireless communication method.   The resonance frequency of the transmission / reception antenna is switched based on a determination result in a period in which a signal is transmitted to the predetermined wireless communication medium by the transmission / reception antenna and a period in which a signal is received from the predetermined wireless communication medium by the transmission / reception antenna. The wireless communication method according to claim 13, wherein control is performed. A non-contact type IC card reader / writer device that performs transmission and reception of data with an IC card by wireless communication and performs predetermined data processing,
Transmitting means for transmitting a signal to the IC card, having a first resonance frequency that resonates and resonates with the resonance frequency of the IC card within a predetermined communication range with the IC card;
Receiving means for receiving a signal from the IC card having a second resonance frequency that is non-resonant with the resonance frequency of the IC card in a predetermined communication range with the IC card;
Control means for transmitting and receiving data to and from the IC card via the transmitting means and receiving means and performing predetermined data processing;
A non-contact type IC card reader / writer device comprising:

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