JP2009296061A - Information processor, communication method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an information processor capable of extending a communication distance between a reader-writer and the information processor; a communication method; and a program. <P>SOLUTION: The information processor includes: a communication antenna for receiving the carrier signals of a prescribed frequency transmitted from an external device, in non-contact manner; a reception detection part for detecting the reception of the carrier signals in the communication antenna; a demodulation part for demodulating the carrier signals received by the communication antenna; a data processing part for data-processing the carrier signals demodulated by the demodulation part on the basis of the detected result of the reception detection part and outputting a first control signal for controlling load modulation relating to a response to the external device and a second control signal for controlling the change of an impedance in the view from the external device corresponding to a processing result; a load modulation part for selectively performing the load modulation on the basis of the first control signal; and an impedance adjusting part for selectively switching the state of the connection between the communication antenna and the data processing part and changing an impedance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information processing apparatus, a communication method, and a program.

  In recent years, readers / writers (or communication devices / information processing with reader / writer functions) such as non-contact IC (Integrated Circuit) cards, RFID (Radio Frequency Identification) tags, mobile phones equipped with non-contact IC chips, etc. Information processing devices that can communicate in a non-contact manner with devices have become widespread.

  A reader / writer and an information processing apparatus such as an IC card or a mobile phone use a magnetic field (carrier wave) having a specific frequency such as 13.56 MHz for communication. Specifically, the reader / writer transmits a carrier wave carrying a carrier wave signal, and an information processing device such as an IC card that has received the carrier wave by an antenna returns a response signal to the carrier wave signal received by load modulation, whereby the reader / writer / The writer and the information processing apparatus can communicate with each other.

  In addition, an information processing apparatus capable of communicating in a contactless manner with the reader / writer as described above includes a tamper-resistant IC chip, so that, for example, transmission / reception of data such as electronic money where data tampering is a problem Updates can be done safely. Accordingly, the provision of various services using an information processing apparatus equipped with an IC chip capable of non-contact communication with the reader / writer as described above is spreading socially. With the spread of service provision, information processing apparatuses equipped with non-contact IC chips such as IC cards and mobile phones are becoming more widespread.

  Under such circumstances, a technique for further extending a communication distance capable of normal communication between the reader / writer and the information processing apparatus has been developed. As a technique for increasing the resonance frequency of an antenna by providing an intermediate tap on a coil serving as an antenna, for example, Patent Document 1 can be cited. Further, as a technique for performing modulation using power supplied from an internal power supply, for example, Patent Document 2 can be cited.

JP 2007-58381 A JP 2003-30611 A

  However, the conventional information processing apparatus using the technology for increasing the resonance frequency of the antenna by providing an intermediate tap on the coil serving as the antenna merely increases the resonance frequency. For this reason, a conventional information processing apparatus using a technique for increasing the resonance frequency of an antenna cannot always maintain an optimal resonance frequency in communication with a reader / writer. Therefore, even if a technique for increasing the resonance frequency of the antenna is used, there is no way to increase the communication distance that allows normal communication between the reader / writer and the information processing apparatus.

  In addition, a conventional information processing apparatus using a technique for performing modulation using power supplied from an internal power supply requires a power supply for communication with a reader / writer. Therefore, a technique for performing modulation using the power supplied from the internal power supply cannot be applied to a device that does not generally have an internal power supply, such as an IC card. Further, even when a technique for performing modulation using power supplied from an internal power supply is applied to a device having an internal power supply, such as a mobile phone, for example, for communication with a reader / writer. It is necessary to always consume power (more precisely, for modulation). Here, there is a limit to the total amount of power that can be supplied by the internal power supply of a mobile phone or the like. For this reason, when a technology for performing modulation using power supplied from an internal power source is applied to a portable device such as a mobile phone, power limited to each communication with the reader / writer is used. In order to consume, the time which can make the other function which the said apparatus has work correspondingly will be deleted. Therefore, even if a technique for performing modulation using power supplied from the internal power supply is applied to a device having an internal power supply, for example, adverse effects such as shortening the drive time of the device are unavoidable.

  Therefore, even if the conventional technology for further extending the communication distance that allows normal communication between the reader / writer and the information processing apparatus is applied, the communication distance between the reader / writer and the information processing apparatus is increased. It is not always possible.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a novel communication distance that can extend the communication distance between the reader / writer and the information processing apparatus. Another object of the present invention is to provide an improved information processing apparatus, communication method, and program.

  To achieve the above object, according to a first aspect of the present invention, a communication antenna that receives a carrier signal of a predetermined frequency transmitted from an external device in a contactless manner, and reception of the carrier signal at the communication antenna. A reception detecting unit for detecting the carrier signal, a demodulating unit for demodulating the carrier signal received by the communication antenna, and data processing on the carrier signal demodulated by the demodulating unit based on a detection result of the reception detecting unit. In response, a data processing unit that outputs a first control signal that controls load modulation related to a response to the external device and a second control signal that controls a change in impedance viewed from the external device, and the first control A load modulation unit that selectively performs the load modulation based on a signal, and a connection state between the communication antenna and the data processing unit based on the second control signal. For example, the information processing apparatus comprising an impedance adjusting portion for changing the impedance is provided.

  With this configuration, it is possible to extend a communication distance that allows normal communication between the reader / writer and the information processing apparatus.

  A power source that supplies a driving voltage used by the data processing unit to perform data processing; and a switching unit that selectively supplies the driving voltage to the data processing unit based on a detection result in the reception detection unit; May be further provided.

  The data processor outputs a first first control signal for connecting the communication antenna and the data processor when the reception detector detects reception of the carrier signal. When the data processing is completed, the second first control signal for releasing the connection state between the communication antenna and the data processing unit is output, and the second first control signal is output. The second control signal may be output in synchronization with the output.

  In addition, when the data processing is completed, the data processing unit outputs a second first control signal for releasing the connection state between the communication antenna and the data processing unit, and the second processing unit The second control signal is output in synchronization with the output of the first control signal, and when the output of the second control signal is completed, the communication antenna and the data processing unit are connected to each other. The first first control signal may be output.

  The information processing apparatus may be a portable communication apparatus.

  The information processing apparatus may be an IC card.

  In order to achieve the above object, according to a second aspect of the present invention, a carrier wave signal of a predetermined frequency transmitted from an external device is received in a contactless manner, and the carrier wave signal in the receiving step Detecting the reception of the carrier signal, demodulating the carrier signal received in the receiving step, and data processing the carrier signal demodulated in the demodulating step based on the detection result in the detecting step, Outputting a first control signal for controlling load modulation related to a response to the external device and a second control signal for controlling a change in impedance viewed from the external device according to a processing result; A step of selectively performing the load modulation based on the control signal, and the external device based on the second control signal. Communication method and a step of selectively varying the impedance is provided.

  By using such a method, it is possible to extend the communication distance that allows normal communication between the reader / writer and the information processing apparatus.

  To achieve the above object, according to a third aspect of the present invention, a step of receiving a carrier signal of a predetermined frequency transmitted from an external device in a non-contact manner, and receiving the carrier signal in the step of receiving. Detecting the carrier signal received in the receiving step, demodulating the carrier signal demodulated in the demodulating step based on the detection result in the detecting step, and processing according to the processing result Outputting a first control signal for controlling load modulation related to a response to the external device and a second control signal for controlling a change in impedance viewed from the external device, based on the first control signal A step of selectively performing load modulation, based on the second control signal, an impedance viewed from the external device; Program for executing the step of changing the 択的 the computer is provided.

  By using such a program, it is possible to extend the communication distance that allows normal communication between the reader / writer and the information processing apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the communication distance which can communicate normally between a reader / writer and information processing apparatus can be extended.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(Outline of communication system according to an embodiment of the present invention)
First, an outline of a communication system (hereinafter referred to as “communication system 1000”) according to an embodiment of the present invention will be described. FIG. 1 is an explanatory diagram for explaining an outline of a communication system 1000 according to an embodiment of the present invention. Here, FIG. 1 shows an example of a communication system 1000 including a reader / writer 100 (external device) and an information processing device 150, and an IC card is shown as an example of the information processing device 150.

  In the communication system 1000, the reader / writer 100 transmits a magnetic field having a specific frequency such as 13.56 MHz (hereinafter referred to as “carrier wave”), and the information processing apparatus 150 that has received the carrier wave performs load modulation. Communication is performed between the reader / writer 100 and the information processing apparatus 150. Hereinafter, how the communication between the reader / writer 100 and the information processing apparatus 150 is performed will be described.

  FIG. 2 is a first explanatory diagram for explaining an outline of communication in the communication system 1000 according to the embodiment of the present invention. Here, FIG. 2 schematically shows configurations of the reader / writer 100 and the information processing apparatus 150, respectively.

[Outline of Reader / Writer 100]
Referring to FIG. 2, the reader / writer 100 includes a carrier wave signal generation unit 102 and a carrier wave transmission unit 104.

  The carrier signal generation unit 102 receives a carrier signal generation command from a control unit (not shown), and generates a carrier signal according to the carrier signal generation command. Here, in FIG. 2, an AC power supply is shown as the carrier signal generation unit 102, but the carrier signal generation unit 102 according to the embodiment of the present invention is not limited to the above, for example, ASK modulation (Amplitude Shift Keying) And a modulation circuit (not shown) for amplifying the output of the modulation circuit. Note that the carrier wave signal generated by the carrier wave signal generation unit 102 can include, for example, various processing instructions for the information processing device 150 and data to be processed, but is not limited thereto.

  The carrier wave transmission unit 104 includes, for example, a coil (inductor) having a predetermined inductance, and transmits a carrier wave corresponding to the carrier wave signal generated by the carrier wave signal generation unit 102. The carrier wave transmission unit 104 can also receive a response signal from the information processing apparatus 150. That is, the carrier wave transmission unit 104 can serve as a communication antenna for the reader / writer 100. Here, FIG. 2 shows an example in which the carrier wave transmission unit 104 is configured by a resonance circuit including a coil and a capacitor.

  The reader / writer 100 can transmit a carrier wave according to the carrier wave signal with the above configuration.

[Outline of Information Processing Device 150]
The information processing apparatus 150 includes a communication antenna 152 and a load Z. Here, the load Z is equivalent to an IC chip related to communication with the reader / writer 100 provided in the information processing apparatus 150.

  The communication antenna 152 includes a resonance circuit including a coil (inductor) having a predetermined inductance and a capacitor having a predetermined capacitance, and generates an induced voltage by electromagnetic induction in response to reception of a carrier wave. Then, the communication antenna 152 outputs a reception voltage obtained by resonating the induced voltage at a predetermined resonance frequency. Here, the resonance frequency in the communication antenna 152 can be set according to the frequency of the carrier wave such as 13.56 MHz, for example. With the above configuration, the communication antenna 152 can receive a carrier wave and generate a demagnetizing field with respect to the carrier wave by load modulation to respond to the reader / writer 100.

  Here, the load modulation is a modulation method in which the information processing apparatus 150 responds to the reader / writer 100 by selectively changing the impedance (load impedance). The reader / writer 100 detects a change in impedance of the information processing apparatus 150 as viewed from the reader / writer 100 caused by load modulation as a response signal from the information processing apparatus 150. More specifically, the information processing apparatus 150 generates a demagnetizing field with respect to the carrier wave by load modulation according to the response signal to be transmitted. The response signal is demodulated by detecting a change in the voltage generated in the signal.

  FIG. 3 is a second explanatory diagram for explaining the outline of communication in the communication system 1000 according to the embodiment of the present invention. Here, FIG. 3 shows that the distance between the reader / writer 100 and the information processing apparatus 150 is kept at a certain distance, and the impedance of the IC chip included in the information processing apparatus 150 is changed between 0.1Ω and 1MΩ. This shows an example of a change in voltage at the antenna end P of the reader / writer 100 in the case of the above.

  As shown in FIG. 3, it can be seen that the voltage at the antenna end of the reader / writer 100 changes according to the change in impedance of the information processing apparatus 150. Therefore, the reader / writer 100 can demodulate the response signal transmitted from the information processing device 150 by detecting the difference “ΔV” of the voltage at the antenna end before and after the impedance change in the information processing device 150. . Here, the demodulation of the response signal using the voltage difference “ΔV” at the antenna end corresponds to demodulating the response signal using the change in the amplitude of the voltage at the antenna end.

  In the communication system 1000, as described above, the reader / writer 100 transmits a carrier wave and the information processing apparatus 150 performs load modulation, so that the reader / writer 100 and the information processing apparatus 150 communicate in a non-contact manner. Is done.

(Approach for extending the communication distance according to the embodiment of the present invention)
As described above, in the communication system 1000, a response signal is transmitted from the information processing device 150 to the reader / writer 100 when the information processing device 150 changes the impedance and the reader / writer 100 detects the change in the impedance. Is done. Here, as shown in FIG. 3, the greater the change in impedance in the information processing apparatus 150, the greater the voltage difference “ΔV” at the antenna end of the reader / writer 100. Further, as the distance between the reader / writer 100 and the information processing apparatus 150 increases, the coupling between the communication antenna (carrier transmission unit 104) of the reader / writer 100 and the communication antenna 152 of the information processing apparatus 150 becomes weaker. Therefore, the voltage difference “ΔV” at the antenna end of the reader / writer 100 becomes smaller. That is, if the information processing device 150 further increases the impedance change, the reader / writer 100 responds with a voltage difference “ΔV” even if the distance between the reader / writer 100 and the information processing device 150 increases. The possibility of being detected as a signal can be further increased.

  Therefore, in the communication system 1000, the information processing apparatus 150 increases the change in impedance when the response signal is transmitted, thereby extending the communication distance between the reader / writer 100 and the information processing apparatus 150.

(Reason why the conventional communication system cannot use the approach according to the embodiment of the present invention)
Prior to describing the configuration of the communication system 1000 that can extend the communication distance using the approach according to the embodiment of the present invention, the conventional communication system cannot use the approach according to the embodiment of the present invention. The reason will be explained.

[Configuration of conventional communication system]
FIG. 4 is an explanatory diagram showing an example of a configuration of a conventional communication system. Referring to FIG. 4, the conventional communication system includes a reader / writer 10 and an information processing apparatus 50.

[Reader / Writer 10]
The reader / writer 10 includes a carrier wave signal generation unit 12, a carrier wave transmission unit 14, a demodulation unit 16, and a control unit 18. The reader / writer 10 is connected to, for example, the host computer 20 and can transmit a carrier wave signal in response to a transmission command from the host computer 20.

  The carrier signal generation unit 12 receives a carrier signal generation command from the control unit 18 and generates a carrier signal according to the carrier signal generation command.

  The carrier wave transmission unit 14 includes, for example, a coil (inductor) having a predetermined inductance, and transmits a carrier wave corresponding to the carrier wave signal generated by the carrier wave signal generation unit 12. The carrier wave transmission unit 14 can also receive a response signal from the information processing apparatus 50. That is, the carrier wave transmission unit 14 serves as a communication antenna for the reader / writer 10.

  The demodulation unit 16 demodulates the response signal from the information processing device 50 by, for example, detecting the change in the amplitude of the voltage at the antenna end of the carrier wave transmission unit 14 by envelope detection and binarizing the detected signal.

  The control unit 18 is configured by, for example, an MPU (Micro Processing Unit) or the like, and transmits data demodulated by the demodulation unit 16 to the host computer 20 or issues a carrier signal generation command based on the data demodulated by the demodulation unit 16. Various processes such as generation are performed.

  The reader / writer 10 can demodulate a response signal transmitted from the information processing apparatus 50 by transmitting a carrier wave with the above-described configuration, for example.

[Information processing apparatus 50]
The information processing apparatus 50 includes a communication antenna 52 that can receive a carrier wave, and an IC chip 54 that can demodulate and process a carrier wave signal based on the received carrier wave and transmit a response signal by load modulation.

  The communication antenna 52 includes a resonance circuit including a coil (inductor) L10 having a predetermined inductance and a capacitor C10 having a predetermined capacitance, and generates an induced voltage by electromagnetic induction in response to reception of a carrier wave. Then, the communication antenna 52 outputs a reception voltage obtained by resonating the induced voltage at a predetermined resonance frequency. Here, the resonance frequency in the communication antenna 52 is set according to the frequency of the carrier wave such as 13.56 MHz, for example. With the above configuration, the communication antenna 52 receives a carrier wave and transmits a response signal by load modulation performed in the load modulation unit 66 included in the IC chip 54.

<Configuration of IC chip 54>
The IC chip 54 includes a carrier detection unit 56, a detection unit 58, a regulator (Regulator) 60, a demodulation unit 62, a data processing unit 64, and a load modulation unit 66. Further, the IC chip 54 includes a ROM 68 in which control data such as a program used by the data processing unit 64 and calculation parameters are recorded, and a RAM 70 that primarily stores a program executed by the data processing unit 64, calculation results, an execution state, and the like. And a recording medium 72 capable of storing data to be processed by the data processing unit 64. The data processing unit 64, the ROM 68, the RAM 70, and the recording medium 72 are connected by, for example, a bus 74 as a data transmission path.

  The carrier detection unit 56 generates, for example, a rectangular detection signal based on the reception voltage transmitted from the communication antenna 52, and transmits the detection signal to the data processing unit 64. The data processing unit 64 uses the transmitted detection signal as a processing clock for data processing, for example. Here, since the detection signal is based on the reception voltage transmitted from the communication antenna 52, it is synchronized with the frequency of the carrier wave transmitted from the reader / writer 10. Therefore, the information processing apparatus 50 includes the carrier detection unit 56 and can perform processing with the reader / writer 10 in synchronization with the reader / writer 10.

  The detector 58 rectifies the received voltage output from the communication antenna 52. Here, the detection unit 58 includes, for example, a diode D10 and a capacitor C11.

  The regulator 60 smoothes and constants the received voltage and outputs a drive voltage to the data processing unit 64. Here, the regulator 60 uses the direct current component of the received voltage as the drive voltage.

  The demodulator 62 demodulates the carrier wave signal based on the received voltage, and outputs data corresponding to the carrier wave signal included in the carrier wave (for example, a binarized data signal of high level and low level). Here, the demodulator 62 outputs the AC component of the received voltage as data.

  The data processing unit 64 is driven by using the drive voltage output from the regulator 60 as a power source, and processes the data demodulated by the demodulation unit 62. Here, the data processing unit 64 is configured by an MPU, for example. Further, the data processing unit 64 transmits a control signal for selectively controlling load modulation to the load modulation unit 66 according to the processing result.

  The load modulation unit 66 includes, for example, a load Z and a switch SW10, and performs load modulation by selectively connecting the load Z according to a control signal transmitted from the data processing unit 64. Here, the switch SW10 is configured by, for example, a p-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an n-channel MOSFET.

  By performing load modulation in the load modulator 66, the impedance of the information processing apparatus 50 as viewed from the reader / writer 10 changes. The reader / writer 10 detects the change in the impedance by using, for example, the change in the amplitude of the voltage at the antenna end of the carrier wave transmission unit 14, thereby receiving the response signal transmitted from the information processing apparatus 50 to the reader / writer 10. Receive.

  The information processing apparatus 50 receives, for example, the carrier wave transmitted from the reader / writer 10 according to the above configuration, processes the carrier wave signal, and transmits a response signal corresponding to the processing result to the reader / writer 10. can do.

[Problems in conventional communication systems]
As shown in FIG. 4, in the conventional communication system, the information processing device 50 selectively responds to the reader / writer 10 by changing the impedance by selectively connecting the load Z and performing load modulation. Here, as means for applying the approach according to the embodiment of the present invention to the conventional communication system, for example, a resistor having a larger resistance value is used as the load Z.

  However, when the information processing apparatus 50 configures the load Z of the load modulation unit 66 with a resistor having a larger resistance value, the power consumed in the load Z is larger. Here, the power that the information processing apparatus 50 can obtain from the received carrier wave is limited. Therefore, in the above case, the drive voltage output from the regulator 60 becomes small, and the data processing unit 64 may not be able to drive using the drive voltage. In particular, when the information processing apparatus 50 is an apparatus that does not have a separate power source, such as an IC card, for example, the data processing unit 64 cannot be driven using a drive voltage. 10 and the information processing apparatus 50 are not established. Moreover, even if the information processing apparatus 50 has a configuration having an internal power supply, in the above case, for example, adverse effects such as shortening the drive time of the information processing apparatus 50 are unavoidable.

  Therefore, even if the approach according to the embodiment of the present invention is applied to the conventional communication system as shown in FIG. 4, the communication distance between the reader / writer 10 and the information processing apparatus 50 cannot always be extended. Absent.

  As described above, even if the approach according to the embodiment of the present invention is applied to the conventional communication system, the effect of stably extending the communication distance between the reader / writer and the information processing apparatus cannot be expected. Then, next, the structure of the communication system 1000 which concerns on embodiment of this invention which can implement | achieve extension of the communication distance by the approach which concerns on embodiment of this invention is demonstrated.

(Communication system according to the first embodiment)
FIG. 5 is an explanatory diagram showing the communication system according to the first embodiment of the present invention. Referring to FIG. 5, the communication system according to the first embodiment (hereinafter sometimes referred to as “communication system 1100”) includes a reader / writer 100 (external device) and an information processing device 150.

[Reader / Writer 100]
The reader / writer 100 includes a carrier wave signal generation unit 102, a carrier wave transmission unit 104, a demodulation unit 106, and a control unit 108. The reader / writer 100 is connected to, for example, the host computer 120 and can transmit a carrier wave signal in response to a transmission command from the host computer 120.

  The reader / writer 100 also stores a ROM (Read Only Memory; not shown) in which control data such as a program used by the control unit 108 and calculation parameters are recorded, a program executed by the control unit 108, and the like. RAM (Random Access Memory; not shown), a register (register; not shown) for holding the calculation result and execution state in the control unit 108, an encryption circuit (not shown) for encrypting communication, a reader / A storage unit (not shown) capable of storing applications, data, and the like used in the writer 100, an interface (not shown) for connecting to the host computer 120 and other circuits, and the like may be provided. The reader / writer 100 can connect each component by a bus as a data transmission path, for example. Here, examples of the storage unit (not shown) include a magnetic recording medium such as a hard disk and a non-volatile memory such as a flash memory. I can't. Examples of the interface include a UART (Universal Asynchronous Receiver Transmitter) and a network terminal, but are not limited to the above.

  The carrier signal generation unit 102 receives a carrier signal generation command from the control unit 108 and generates a carrier signal according to the carrier signal generation command. Here, in FIG. 5, an AC power supply is shown as the carrier signal generation unit 102, but the carrier signal generation unit 102 according to the embodiment of the present invention is not limited to the above. For example, the carrier wave signal generation unit 102 according to the embodiment of the present invention can be configured by a modulation circuit (not shown) that performs ASK modulation and an amplification circuit (not shown) that amplifies the output of the modulation circuit. Note that the carrier wave signal generated by the carrier wave signal generation unit 102 can include, for example, various processing instructions for the information processing device 150 and data to be processed, but is not limited thereto. For example, the carrier wave signal according to the embodiment of the present invention may be a signal for causing the carrier wave transmission unit 104 to generate a carrier wave that supplies power to the information processing apparatus 150.

  The carrier wave transmission unit 104 includes, for example, a coil (inductor) having a predetermined inductance, and transmits a carrier wave corresponding to the carrier wave signal generated by the carrier wave signal generation unit 102. The carrier wave transmission unit 104 can also receive a response signal from the information processing apparatus 150. That is, the carrier wave transmission unit 104 can serve as a communication antenna for the reader / writer 100. Here, FIG. 5 illustrates an example in which the carrier transmission unit 104 is configured by a coil, but the carrier transmission unit 104 according to the embodiment of the present invention is not limited to the above, and further includes, for example, a capacitor. A resonance circuit may be configured by the above.

  For example, the demodulation unit 106 demodulates the response signal from the information processing device 150 by performing envelope detection on the amplitude change of the voltage at the antenna end of the carrier wave transmission unit 104 and binarizing the detected signal. Note that the means for demodulating the response signal in the demodulation unit 106 is not limited to the above, and for example, the response signal can be demodulated using the phase change of the voltage at the antenna end of the carrier wave transmission unit 104.

  The control unit 108 includes, for example, an MPU and transmits various data demodulated by the demodulation unit 106 to the host computer 120, or generates a carrier signal generation command based on the data demodulated by the demodulation unit 106. Can be processed.

  For example, the reader / writer 100 can demodulate a response signal transmitted from the information processing apparatus 150 by transmitting a carrier wave with the above-described configuration.

[Information processing apparatus 150]
The information processing apparatus 150 includes a communication antenna 152 that can receive a carrier wave, and an IC chip 154 that demodulates and processes a carrier wave signal based on the received carrier wave and transmits a response signal by load modulation.

  For example, the communication antenna 152 includes a resonance circuit including a coil (inductor) L1 having a predetermined inductance and a capacitor C1 having a predetermined capacitance, and generates an induced voltage by electromagnetic induction in response to reception of a carrier wave. Let Then, the communication antenna 152 outputs a reception voltage obtained by resonating the induced voltage at a predetermined resonance frequency. Here, the resonance frequency in the communication antenna 152 is set according to the frequency of the carrier wave such as 13.56 MHz, for example. The communication antenna 152 receives a carrier wave with the above-described configuration, and transmits a response signal by load modulation performed in the load modulation unit 166 included in the IC chip 154.

[Configuration of IC chip 154]
The IC chip 154 includes a carrier detection unit 156 (reception detection unit), a detection unit 158, a regulator 160, a demodulation unit 162, a data processing unit 164, a load modulation unit 166, and an impedance adjustment unit 168. Although not shown in FIG. 5, the IC chip 154 can further include, for example, a protection circuit (not shown) for preventing an overvoltage or overcurrent from being applied to the data processing unit 164. Here, examples of the protection circuit (not shown) include a clamp circuit composed of a diode or the like, but are not limited thereto.

  Further, the IC chip 154 includes a ROM 170 in which control data such as a program used by the data processing unit 164 and calculation parameters are recorded, and a RAM 172 that primarily stores programs executed by the data processing unit 164, calculation results, execution states, and the like. And a recording medium 174 capable of storing data to be processed by the data processing unit 164. The data processing unit 164, the ROM 170, the RAM 172, and the recording medium 174 are connected by, for example, a bus 176 as a data transmission path. Here, as the recording medium 174, for example, EEPROM (Electrically Erasable and Programmable Read Only Memory), flash memory, MRAM (Magnetoresistive Random Access Memory), FeRAM (Ferroelectric Random Access Memory), PRAM (Phase change Random Access Memory), etc. However, the present invention is not limited to the above.

  The carrier detection unit 156 generates, for example, a rectangular detection signal based on the reception voltage transmitted from the communication antenna 152 and transmits the detection signal to the data processing unit 164. In addition, the data processing unit 164 uses the transmitted detection signal as a processing clock for data processing, for example. Here, since the detection signal is based on the reception voltage transmitted from the communication antenna 152, it is synchronized with the frequency of the carrier wave transmitted from the reader / writer 100. Therefore, the information processing apparatus 150 includes the carrier detection unit 156, and can perform processing with the reader / writer 100 in synchronization with the reader / writer 100.

  The detector 158 rectifies the reception voltage output from the communication antenna 152. Here, the detection unit 158 can be configured by the diode D1 and the capacitor C2, but is not limited thereto.

  The regulator 160 smoothes and constants the received voltage and outputs a drive voltage to the data processing unit 164. Here, the regulator 160 can use the DC component of the received voltage as the drive voltage.

  The demodulator 162 demodulates the carrier wave signal based on the received voltage, and outputs data corresponding to the carrier wave signal included in the carrier wave (for example, a binarized data signal of high level and low level). Here, the demodulator 162 can output the AC component of the received voltage as data.

  The data processing unit 164 is driven by using the drive voltage output from the regulator 160 as a power source, and processes the data demodulated by the demodulation unit 162. Here, the data processing unit 164 can be configured by, for example, an MPU, but is not limited thereto.

  The data processing unit 164 also controls the first control signal for controlling the load modulation related to the response to the reader / writer 100 (external device) and the impedance as viewed from the reader / writer 100 (external device) according to the processing result. A second control signal for controlling the change is selectively generated. Then, the data processing unit 164 selectively outputs the first control signal to the load modulation unit 166 and selectively outputs the second control signal to the impedance adjustment unit 168. A selective output example of the first control signal and the second control signal in the data processing unit 164 will be described later.

  The load modulation unit 166 includes, for example, a load Z and a switch SW1, and performs load modulation by selectively connecting (enabling) the load Z according to the first control signal transmitted from the data processing unit 164. Do. Here, the load Z is constituted by a resistor having a predetermined resistance value, for example, but is not limited thereto. Further, the switch SW1 is constituted by, for example, a p-channel type MOSFET or an n-channel type MOSFET, but is not limited thereto.

  When load modulation is performed in the load modulation unit 166, the impedance of the information processing apparatus 150 viewed from the reader / writer 100 changes.

  The impedance adjustment unit 168 includes, for example, a switch SW2 and selectively switches the connection state between the communication antenna 152 and the data processing unit 164 according to the second control signal transmitted from the data processing unit 164. Here, when the switch SW2 is OFF, the impedance viewed from the reader / writer 100 is increased corresponding to the demodulator 162 and the data processor 164. Further, when the load modulation unit 166 performs load modulation with the switch SW2 turned off as described above, the change in impedance seen from the reader / writer 100 caused by load modulation is the state in which the switch SW2 is turned on. Be bigger than when. Therefore, the impedance adjustment unit 168 serves to adjust the impedance viewed from the reader / writer 100 in the information processing apparatus 150.

  Further, the switch SW2 can be constituted by, for example, a p-channel type MOSFET or an n-channel type MOSFET, but is not limited thereto. For example, the switch SW2 can be realized by an arbitrary element that can be turned on / off according to the second control signal.

  Here, the resistance value of the load Z included in the load modulation unit 166 does not depend on the impedance adjustment in the impedance adjustment unit 168. That is, the information processing apparatus 150 includes the impedance adjustment unit 168, so that the impedance change viewed from the reader / writer 100 can be increased without increasing the power consumed in the load modulation.

  With the above-described configuration, the IC chip 154 can process the carrier wave signal received by the communication antenna 152 and transmit a response signal from the communication antenna 152 by load modulation. Further, the IC chip 154 includes the impedance adjustment unit 168, so that the impedance change seen from the reader / writer 100 caused by load modulation can be made larger. 5 illustrates a configuration in which the information processing apparatus 150 includes the IC chip 154. However, the configuration is not limited to the above, and the configuration of the IC chip 154 may not be realized as an IC chip.

  Therefore, the information processing apparatus 150 can further extend the communication distance that allows normal communication between the reader / writer 100 and the information processing apparatus 150 with the above configuration.

[Flow of Processing in Communication System 1100]
Next, a flow of processing related to communication in the communication system 1100 including the reader / writer 100 and the information processing apparatus 150 described above is shown.

[First example]
FIG. 6 is an explanatory diagram illustrating a first example of a process flow related to communication in the communication system 1100 according to the first embodiment of the present invention. In FIG. 6, for convenience of explanation, the response (load modulation) from the information processing apparatus 150 to the reader / writer 100 is shown only once, but it is not limited to the above. For example, in the communication system 1100, the processing from step S102 to S112 shown in FIG. 6 can be repeated a plurality of times until the processing related to the service provided in the communication system 1100 is completed.

  The information processing apparatus 150 detects reception of a carrier wave transmitted periodically / non-periodically or continuously from the reader / writer 100 (S100). Here, in the information processing apparatus 150, for example, the carrier detection unit 156 transmits the detection signal based on the induced voltage generated by electromagnetic induction in the communication antenna 152 to the data processing unit 164 to perform the process of step S <b> 100. Can do.

  The information processing apparatus 150 that has detected the reception of the carrier wave in step S100 switches the switch SW2 of the impedance adjustment unit 168 to the on state (S102). Here, in the information processing apparatus 150, the first first control for the data processing unit 164 to connect the communication antenna 152 and the data processing unit 164 based on the detection signal transmitted from the carrier detection unit 156. By outputting the signal, the process of step S102 can be performed. In addition, the signal level of the first first control signal is set to a high level or a low level according to, for example, the conductivity type of the switch SW2 of the impedance adjustment unit 168.

  The communication antenna 152 and the data processing unit 164 are connected by the processing in step S102. Therefore, the information processing apparatus 150 is ready for processing the carrier wave signal transmitted from the reader / writer 100 by the process of step S102.

  The reader / writer 100 transmits a carrier wave carrying a carrier signal indicating various commands (S104). Here, as the various commands, for example, a communication request related to polling for capturing the information processing apparatus 150, and a command for reading / writing data stored in the recording medium 174 of the IC chip 154 Data for recording on the recording medium 174 can be mentioned, but is not limited thereto.

  The information processing apparatus 150 that has received the carrier wave transmitted in step S104 demodulates the carrier wave signal, and performs data processing according to the various commands based on the demodulated carrier wave signal (S106).

  When the information processing apparatus 150 makes a response to the reader / writer 100 as a result of the data processing in step S106, the information processing apparatus 150 switches the switch SW2 of the impedance adjustment unit 168 to an off state (S108). Here, in the information processing apparatus 150, the data processing unit 164 outputs the second first control signal for releasing the connection state between the communication antenna 152 and the data processing unit 164, thereby performing the process of step S108. It can be carried out. In addition, the signal level of the second first control signal is set to a high level or a low level according to, for example, the conductivity type of the switch SW2 of the impedance adjustment unit 168.

  Further, when the information processing apparatus 150 makes a response to the reader / writer 100 as a result of the processing in step S106, it performs load modulation and transmits a response signal (S110). Here, the information processing apparatus 150 can perform the process of step S110 by the data processing unit 164 selectively outputting the second control information to the load modulation unit 166 according to the content of the response.

  6 shows an example in which the process of step S110 is performed after the process of step S108, the present invention is not limited to the above. For example, the information processing apparatus 150 can perform the process of step S108 and the process of step S110 in synchronization. If a series of processing with the reader / writer 100 has not been completed, the information processing apparatus 150 repeats the processing from step S102 after the processing of step S110, for example.

  For example, the reader / writer 100 demodulates the response signal transmitted in step S110 based on a change in the voltage at the antenna end of the carrier wave transmission unit 104, and performs data processing related to the response signal (S112). In addition, when the series of processing with the information processing apparatus 150 has not been completed, the reader / writer 100 repeats the processing from step S104.

  In the processing according to the first example in the communication system 1100, as shown in FIG. 6, before the information processing apparatus 150 makes a response by load modulation or in synchronization with the start of load modulation, the impedance adjustment unit 168 Switch SW2 is turned off. Therefore, the information processing apparatus 150 can make the change in impedance viewed from the reader / writer 100 caused by load modulation larger, so that the communication distance between the reader / writer 100 and the information processing apparatus 150 can be further increased. Can be stretched.

[Second example]
FIG. 7 is an explanatory diagram illustrating a second example of a processing flow related to communication in the communication system 1100 according to the first embodiment of the present invention. In FIG. 7, for convenience of explanation, the response (load modulation) from the information processing apparatus 150 to the reader / writer 100 is shown only once, but the present invention is not limited to the above. For example, in the communication system 1100, the process from step S202 to S210 shown in FIG. 7 can be repeated a plurality of times until the process related to the service is completed.

  The information processing apparatus 150 detects reception of a carrier wave transmitted periodically / non-periodically or continuously from the reader / writer 100 as in step S100 shown in FIG. 6 (S200).

  The reader / writer 100 transmits a carrier wave carrying a carrier signal indicating various commands, similarly to step S104 shown in FIG. 6 (S202).

  The information processing apparatus 150 that has received the carrier wave transmitted in step S202 demodulates the carrier wave signal and performs data processing according to the various commands based on the demodulated carrier wave signal, as in step S106 shown in FIG. (S204).

  When the information processing apparatus 150 makes a response to the reader / writer 100 as a result of the data processing in step S204, the switch SW2 of the impedance adjustment unit 168 is turned off as in step S108 shown in FIG. (S206).

  When the information processing apparatus 150 makes a response to the reader / writer 100 as a result of the process in step S204, the information processing apparatus 150 performs load modulation and transmits a response signal as in step S110 shown in FIG. 6 (S208). ).

  FIG. 7 illustrates an example in which the process of step S208 is performed after the process of step S206, but is not limited thereto. For example, the information processing apparatus 150 can perform the process of step S206 and the process of step S208 in synchronization. When a series of processing with the reader / writer 100 is not completed, the information processing apparatus 150 responds to various commands transmitted from the reader / writer 100 after the processing of step S208, for example. The processing from step S204 is repeated.

  As in step S112 shown in FIG. 6, the reader / writer 100 demodulates the response signal transmitted in step S208 and performs data processing related to the response signal (S210). Further, when the series of processing with the information processing apparatus 150 is not completed, the reader / writer 100 repeats the processing from step S202.

  When a series of processing with the reader / writer 100 is completed, the information processing apparatus 150 switches the switch SW2 of the impedance adjustment unit 168 to the ON state (S212), similarly to step S102 shown in FIG. Here, the information processing apparatus 150 can determine whether or not a series of processing with the reader / writer 100 is completed based on reception of a processing completion notification transmitted from the reader / writer 100, for example. Yes, but not limited to the above.

  In the processing according to the second example in the communication system 1100, as shown in FIG. 7, before the information processing apparatus 150 responds by load modulation or in synchronization with the start of load modulation, the impedance adjustment unit 168 Switch SW2 is turned off. Therefore, the information processing apparatus 150 can make the change in impedance viewed from the reader / writer 100 caused by load modulation larger, so that the communication distance between the reader / writer 100 and the information processing apparatus 150 can be further increased. Can be stretched.

  As described above, in the communication system 1100 according to the first embodiment, the communication distance can be extended by making the change in impedance viewed from the reader / writer 100 caused by the load modulation by the information processing apparatus 150 larger. Plan. Here, since the information processing apparatus 150 includes the impedance adjustment unit 168 and adjusts the impedance viewed from the reader / writer 100, the power consumption required for load modulation does not depend on the adjustment of the impedance. Therefore, the information processing apparatus 150 can stably extend the communication distance between the reader / writer 100 and the information processing apparatus 150.

  Further, even when the information processing device 150 includes the smaller communication antenna 152, the information processing device 150 can adjust the impedance, so that the effect of shortening the communication distance depending on the size of the communication antenna 152 is suppressed. be able to. Therefore, the information processing apparatus 150 can achieve both reduction in size of the communication antenna 152 and maintenance of a certain communication distance.

  As described above, the reader / writer 100 has been described as a constituent element of the communication system 1100 according to the first embodiment of the present invention, but the embodiment of the present invention is not limited to such a form. Embodiments of the present invention include, for example, a portable communication device such as a mobile phone having a reader / writer function (that is, a function of mainly transmitting a carrier wave), and a computer such as a PC (Personal Computer) having a reader / writer function. It can be applied to various devices.

  Further, although the information processing apparatus 150 has been described as a constituent element of the communication system 1100 according to the first embodiment of the present invention, the embodiment of the present invention is not limited to such a form. The embodiment of the present invention can be applied to various devices that can be driven using power obtained from a carrier wave transmitted from the reader / writer 100, such as an RFID tag and an IC card.

(Program according to communication system 1100 of the first embodiment)
With the program for causing the computer to function as the information processing apparatus 150 according to the first embodiment of the present invention, it is possible to extend the communication distance that allows normal communication between the reader / writer and the information processing apparatus.

(Communication method according to the communication system 1100 of the first embodiment)
Next, a communication method according to the communication system 1100 according to the first embodiment of this invention will be described. FIG. 8 is a flowchart illustrating an example of a communication method according to the communication system 1100 according to the first embodiment of this invention. Here, FIG. 8 shows an example of a communication method applicable to the information processing apparatus 150.

  The information processing apparatus 150 receives the carrier wave transmitted from the reader / writer 100 (S300), and demodulates the carrier wave signal based on the received carrier wave (S302). Here, for example, the information processing apparatus 150 can demodulate the carrier wave signal from the AC component of the induced voltage generated in the communication antenna 152 by electromagnetic induction in response to reception of the carrier wave.

  When the carrier wave signal is demodulated in step S302, the information processing apparatus 150 performs data processing based on the demodulated carrier wave signal (S304). When data processing is performed in step S304, the information processing apparatus 150 determines whether or not to respond to the reader / writer 100 (S306). Here, the information processing apparatus 150 can determine that a response is made when all of the processes performed in step S304 are completed, but is not limited thereto. For example, the information processing apparatus 150 can determine that a response is to be made when the process in step S304 is completed in stages. Here, FIG. 8 illustrates a case where a response is made when all the processes performed in step S304 are completed.

  If it is not determined in step S306 to respond to the reader / writer 100, the information processing apparatus 150 repeats the processing from step S304.

  If it is determined in step S306 that a response to the reader / writer 100 is made, the information processing apparatus 150 adjusts the amount of change in impedance viewed from the reader / writer 100 caused by load modulation (S308). Here, the information processing apparatus 150 can perform the process of step S308 by switching the switch SW2 of the impedance adjustment unit 168 to the off state.

  When the amount of change in impedance is adjusted in step S308, the information processing apparatus 150 performs load modulation and transmits a response signal to the reader / writer 100 (S310).

  By using the communication method illustrated in FIG. 8, the information processing apparatus 150 can extend a communication distance in which communication between the reader / writer 100 and the information processing apparatus 150 can be normally performed.

(Communication system according to the second embodiment)
The communication system 1100 including the information processing apparatus 150 that can be driven using the power obtained from the carrier wave transmitted from the reader / writer 100 has been described as the communication system 1000 according to the embodiment of the present invention. However, the communication system 1000 according to the embodiment of the present invention is not limited to the configuration having the information processing apparatus 150 that can be driven using the power obtained from the carrier wave transmitted from the reader / writer 100. Then, next, the structure which has an information processing apparatus provided with an internal power supply is demonstrated as a communication system (Hereinafter, it may be called "the communication system 1200.") concerning the 2nd Embodiment of this invention.

  FIG. 9 is an explanatory diagram showing a communication system 1200 according to the second embodiment of the present invention. Referring to FIG. 9, the communication system 1200 includes a reader / writer 100 (external device) and an information processing device 200. Here, the reader / writer 100 shown in FIG. 9 can have the same configuration as the reader / writer 100 according to the first embodiment shown in FIG. Therefore, in the following, description of the reader / writer 100 is omitted, and the information processing apparatus 200 is described.

[Information processing apparatus 200]
The information processing apparatus 200 includes a communication antenna 152, an IC chip 202, a power source 204, an MPU 206, a ROM 208, a RAM 210, a recording medium 212, an input / output interface 214, an operation input device 216, and a display device 218. And a communication interface 220. In addition, the information processing apparatus 200 connects each component with a bus 222 as a data transmission path, for example.

  The communication antenna 152 can have a configuration similar to that of the communication antenna 152 illustrated in FIG. Therefore, the communication antenna 152 can receive a carrier wave and generate a demagnetizing field with respect to the carrier wave by load modulation to respond to the reader / writer 100.

  The IC chip 202 demodulates and processes the carrier signal based on the carrier wave received by the communication antenna 152, and transmits a response signal by load modulation. Hereinafter, the configuration of the IC chip 202 will be described.

[Configuration of IC chip 202]
The IC chip 202 includes a carrier detection unit 230 (reception detection unit), a power supply switching unit 232 (switching unit), a detection unit 158, a regulator 160, a demodulation unit 162, a data processing unit 164, and a load modulation unit. 166 and an impedance adjustment unit 168. Although not shown in FIG. 9, the IC chip 202 indicates that, for example, an overvoltage or overcurrent is applied to the data processing unit 164 in the same manner as the IC chip 154 according to the first embodiment shown in FIG. A protection circuit (not shown) may be further provided to prevent this.

  The IC chip 202 includes a ROM 170, a RAM 172, a recording medium 174, a UART 234, and the like. The data processing unit 164, the ROM 170, the RAM 172, the recording medium 174, and the UART 234 are connected by, for example, a bus 176 as a data transmission path. The IC chip 202 is connected to a bus 222 outside the IC chip 202 via a UART 234 that serves as an interface with components outside the IC chip 202. Here, the ROM 170, the RAM 172, and the recording medium 174 can have the same configurations and functions as the ROM 170, the RAM 172, and the recording medium 174 according to the first embodiment shown in FIG.

  Similarly to the carrier detection unit 156 according to the first embodiment illustrated in FIG. 5, the carrier detection unit 230 is based on the reception voltage transmitted from the communication antenna 152, for example, a rectangular detection signal (first detection signal). ) And transmits the detection signal to the data processing unit 164. The carrier detection unit 230 transmits the second detection signal to the power supply switching unit 232 while the reception voltage is transmitted from the communication antenna 152. Here, the second detection signal corresponds to a detection result indicating that a carrier wave (carrier wave signal) has been received. Further, the carrier detection unit 230 can use, for example, the reception voltage itself transmitted from the communication antenna 152 as the second detection signal, but is not limited thereto. For example, the carrier detection unit 230 can also use a signal obtained by dividing the reception voltage as the second detection signal.

  The power supply switching unit 232 includes a switch SW3, and selectively supplies the power VDD supplied from the power source 204 to the data processing unit based on the second detection signal transmitted from the carrier detection unit 230. Here, the switch SW3 is configured by, for example, a p-channel MOSFET or an n-channel MOSFET, but is not limited thereto.

  The detection unit 158 rectifies the reception voltage output from the communication antenna 152 in the same manner as the detection unit 158 according to the first embodiment shown in FIG. Further, similarly to the regulator 160 according to the first embodiment shown in FIG. 5, the regulator 160 smoothes and constants the received voltage and outputs a drive voltage to the data processing unit 164.

  Similarly to the demodulator 162 according to the first embodiment shown in FIG. 5, the demodulator 162 demodulates the carrier signal based on the received voltage, and data corresponding to the carrier signal included in the carrier (for example, high level and (Binary data signal with low level) is output.

  Similarly to the data processing unit 164 according to the first embodiment shown in FIG. 5, the data processing unit 164 is driven by using the drive voltage output from the regulator 160 as a power source, and processes the data demodulated by the demodulation unit 162. Do. In addition, since the voltage VDD is supplied from the power supply 204 to the data processing unit 164 via the power supply switching unit 232, the data processing unit 164 can further perform data processing using the voltage VDD.

  As described above, when the voltage VDD is supplied from the power supply 204 to the data processing unit 164, even if the driving voltage output from the regulator 160 is less than or equal to the value necessary for driving, the data processing unit 164 Data processing can be performed. When the information processing apparatus 200 has the impedance adjusted by the impedance adjusting unit 168 (that is, the state in which SW2 is off) and the impedance is reduced by load modulation, the drive voltage output from the regulator 160 is reduced. Here, in the information processing apparatus 200, since the voltage VDD is supplied from the power supply 204 to the data processing unit 164, it is possible to more reliably prevent the occurrence of a situation where data processing cannot be performed.

  Further, the data processing unit 164 selectively generates a first control signal and a second control signal, respectively, according to the processing result, similarly to the data processing unit 164 according to the first embodiment shown in FIG. . Then, the data processing unit 164 selectively outputs the first control signal to the load modulation unit 166 and selectively outputs the second control signal to the impedance adjustment unit 168.

  The load modulation unit 166 has the same configuration as that of the load modulation unit 166 according to the first embodiment illustrated in FIG. 5, and selectively selects the load Z according to the first control signal transmitted from the data processing unit 164. Load modulation is performed by connecting.

  The impedance adjustment unit 168 has the same configuration as the impedance adjustment unit 168 according to the first embodiment shown in FIG. 5, and the communication antenna 152 and the data processing according to the second control signal transmitted from the data processing unit 164. The state of connection with the unit 164 is selectively switched. That is, the impedance adjustment unit 168 serves to adjust the impedance viewed from the reader / writer 100 in the information processing apparatus 200.

  With the above-described configuration, the IC chip 202 can process the carrier wave signal received by the communication antenna 152 and transmit a response signal from the communication antenna 152 by load modulation. Further, since the IC chip 202 includes the impedance adjustment unit 168, as with the IC chip 154 according to the first embodiment shown in FIG. 5, the impedance change seen from the reader / writer 100 caused by load modulation is larger. Can be. Furthermore, since the IC chip 202 can perform data processing using the voltage VDD supplied from the power supply 204, the data processing can be performed more reliably.

  9 illustrates a configuration in which the information processing apparatus 200 includes the IC chip 202. However, the configuration is not limited to the above, and the configuration of the IC chip 202 may not be realized as an IC chip.

  The power supply 204 is an internal power supply included in the information processing apparatus 200 and supplies a drive voltage to each unit of the information processing apparatus 200. 9 shows that the voltage VDD output from the power supply 204 is supplied to the IC chip 202 (more strictly speaking, the power supply switching unit 232) for convenience of explanation, the present invention is not limited to the above. . Here, as the power source 204, for example, a secondary battery such as a lithium-ion rechargeable battery can be cited, but the power source 204 is not limited to the above.

  The MPU 206 functions as a control unit that controls the entire information processing apparatus 200. The ROM 208 stores control data such as programs and calculation parameters used by the MPU 206, and the RAM 210 primarily stores programs executed by the MPU 206.

  The recording medium 212 functions as a storage unit in the information processing apparatus 200 and stores, for example, various applications. Here, examples of the recording medium 212 include a magnetic recording medium such as a hard disk, and a nonvolatile memory such as an EEPROM, a flash memory, an MRAM, an FeRAM, and a PRAM, but are not limited thereto.

  The input / output interface 214 connects, for example, the operation input device 216 and the display device 218. Here, examples of the input / output interface 214 include a USB (Universal Serial Bus) terminal, a DVI (Digital Visual Interface) terminal, and an HDMI (High-Definition Multimedia Interface) terminal, but are not limited thereto. The operation input device 216 is provided on the information processing apparatus 200 such as buttons, direction keys, a rotary selector such as a jog dial, or a combination thereof, and is connected to the input / output interface 214 inside the information processing apparatus 200. Connected. Further, the display device 218 is provided on the information processing apparatus 200 such as an LCD (Liquid Crystal Display) or an organic EL display (Organic Light Emitting Diode display). Provided and connected to the input / output interface 214 within the information processing apparatus 200. Needless to say, the input / output interface 214 can be connected to an operation input device (for example, a keyboard or a mouse) as an external device of the information processing apparatus 200 or a display device (for example, an external display).

  The communication interface 220 is a communication unit included in the information processing apparatus 200 and functions as a communication unit for performing wireless / wired communication with an external apparatus such as a server (Server) via a network (or directly). . Here, as the network, for example, a wired network such as a LAN or a WAN (Wide Area Network), a wireless WAN (WWAN: Wireless Wide Area Network) via a base station, a wireless MAN (WMAN: Wireless Metropolitan Area Network), etc. Examples include a wireless network or the Internet using a communication protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol), but are not limited thereto. The communication interface 220 includes, for example, a communication antenna and an RF circuit (wireless communication), an IEEE 802.15.1 port and a transmission / reception circuit (wireless communication), an IEEE 802.11b port and a transmission / reception circuit (wireless communication), or a LAN ( (Local Area Network) terminal and transmission / reception circuit (wired communication), but are not limited thereto. For example, the communication interface 220 can be configured to correspond to the network.

  The information processing apparatus 200 includes an IC chip 202 having basically the same configuration as the IC chip 154 according to the first embodiment shown in FIG. 5, and after adjusting the impedance as viewed from the reader / writer 100, Perform load modulation. Therefore, even if the information processing apparatus 200 has the above-described configuration, the information processing apparatus 200 normally operates between the reader / writer 100 and the information processing apparatus 200 as in the information processing apparatus 150 according to the first embodiment illustrated in FIG. The communicable communication distance can be further increased.

  As described above, in the communication system 1200 according to the second embodiment, as with the communication system 1100 according to the first embodiment, the change in impedance viewed from the reader / writer 100 caused by the load modulation by the information processing apparatus 200. The communication distance is extended by increasing the communication distance. Here, since the information processing apparatus 200 includes the impedance adjustment unit 168 and adjusts the impedance viewed from the reader / writer 100, the power consumption required for load modulation does not depend on the adjustment of the impedance. Therefore, the information processing apparatus 200 can stably extend the communication distance between the reader / writer 100 and the information processing apparatus 200.

  Further, even when the information processing apparatus 200 includes the smaller communication antenna 152, the information processing apparatus 200 can adjust the impedance in the same manner as the information processing apparatus 150 according to the first embodiment. The effect of shortening the communication distance due to the size of the communication antenna 152 can be suppressed. Therefore, the information processing apparatus 200 can achieve both reduction in size of the communication antenna 152 and maintenance of a certain communication distance or more.

  Further, the information processing apparatus 200 includes a power source 204 and selectively supplies the voltage VDD to the data processing unit 164 of the IC chip 202 in response to reception of a carrier wave transmitted from the reader / writer 100. Therefore, the information processing apparatus 200 can more reliably prevent a situation in which data processing cannot be performed in the data processing unit 164 of the IC chip 202.

[Modification of Information Processing Apparatus Constructing Communication System 1200 According to Second Embodiment]
In the communication system 1200 according to the second embodiment illustrated in FIG. 9, the information processing apparatus 200 including the IC chip 202 having a configuration in which the load modulation unit 166 is provided in the subsequent stage of the detection unit 158 is illustrated. However, the configuration of the information processing apparatus configuring the communication system according to the second embodiment is not limited to the configuration of FIG.

  FIG. 10 is an explanatory diagram showing a modification of the communication system according to the second embodiment of the present invention. Referring to FIG. 10, the information processing apparatus 250 according to the modification includes an IC chip 202 having a configuration in which a load modulation unit 254 is provided before the detection unit 158. Even with the above configuration, the information processing apparatus 250 can adjust the impedance according to the first adjustment signal and perform load modulation according to the second adjustment signal. Therefore, the information processing apparatus 250 according to the modification can achieve the same effects as the information processing apparatus 200 according to the second embodiment illustrated in FIG.

  Although not shown in the first embodiment, the configuration of the load modulation unit 254 shown in FIG. 10 can be applied to the information processing apparatus 150 according to the first embodiment shown in FIG.

  As described above, the information processing apparatuses 200 and 250 have been described as the constituent elements of the communication system 1200 according to the second embodiment of the present invention, but the embodiment of the present invention is not limited to such a form. The embodiment of the present invention has an internal power source such as a portable communication device such as a mobile phone equipped with an IC chip and a computer such as a PC equipped with an IC chip, and is not contacted with the reader / writer 100. The present invention can be applied to various devices that can communicate.

(Program according to communication system 1200 of the second embodiment)
A communication distance that allows the computer to function as the information processing apparatus 200 (or the information processing apparatus 250) according to the second embodiment of the present invention so that communication can be performed normally between the reader / writer and the information processing apparatus. Can be stretched.

(Communication method according to communication system 1200 of the second embodiment)
Next, a communication method according to the communication system 1200 according to the second embodiment of this invention will be described. FIG. 11 is a flowchart illustrating an example of a communication method according to the communication system 1200 according to the second embodiment of this invention. Here, FIG. 11 illustrates an example of a communication method applicable to the information processing apparatus 200 (or the information processing apparatus 250).

  The information processing apparatus 200 receives the carrier wave transmitted from the reader / writer 100, similarly to step S300 shown in FIG. 8 (S400). When the carrier wave is received in step S400, the information processing apparatus 200 detects the reception of the carrier wave and selectively supplies the power supply voltage (voltage VDD) to the IC chip 202 (S402).

  Further, the information processing apparatus 200 demodulates the carrier wave signal based on the received carrier wave as in step S302 shown in FIG. 8 (S404).

  When the carrier signal is demodulated in step S404, the information processing apparatus 200 performs data processing based on the demodulated carrier signal (S406). Here, the information processing apparatus 200 can perform the process of step S406 using the power supply voltage (voltage VDD) supplied in step S402.

  When data processing is performed in step S406, the information processing apparatus 200 determines whether or not to respond to the reader / writer 100, similarly to step S306 illustrated in FIG. 8 (S408). Here, FIG. 11 illustrates a case where a response is made when all the processes performed in step S406 are completed.

  If it is not determined in step S408 that a response to the reader / writer 100 is to be made, the information processing apparatus 200 repeats the processing from step S406.

  If it is determined in step S408 that a response to the reader / writer 100 is to be made, the information processing apparatus 200, as in step S308 shown in FIG. The amount of change is adjusted (S410).

  When the amount of change in impedance is adjusted in step S410, the information processing apparatus 200 performs load modulation and transmits a response signal to the reader / writer 100, similarly to step S310 shown in FIG. 8 (S412).

  By using the communication method illustrated in FIG. 11, the information processing apparatus 200 can extend a communication distance that allows normal communication between the reader / writer 100 and the information processing apparatus 200. Further, by using the communication method shown in FIG. 11, the information processing apparatus 200 can more reliably prevent the occurrence of a situation where data processing cannot be performed in the data processing unit 164 of the IC chip 202.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above description, it has been shown that a program (computer program) for causing a computer to function as the information processing apparatuses 150, 200, and 250 according to the embodiment of the present invention is provided. Furthermore, a storage medium storing the program can also be provided.

  The configuration described above shows an example of the embodiment of the present invention, and naturally belongs to the technical scope of the present invention.

It is explanatory drawing for demonstrating the outline of the communication system which concerns on embodiment of this invention. It is the 2nd explanatory view for explaining an outline of a communications system concerning an embodiment of the present invention. It is the 2nd explanatory view for explaining an outline of communication in a communication system concerning an embodiment of the present invention. It is explanatory drawing which shows an example of a structure of the conventional communication system. It is explanatory drawing which shows the communication system which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the 1st example of the flow of the process which concerns on the communication in the communication system which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the 2nd example of the flow of the process which concerns on the communication in the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows an example of the communication method which concerns on the communication system of the 1st Embodiment of this invention. It is explanatory drawing which shows the communication system which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the modification of the communication system which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows an example of the communication method which concerns on the communication system of the 2nd Embodiment of this invention.

Explanation of symbols

10, 100 Reader / writer 16, 62, 106, 162 Demodulator 20, 120 Host computer 50, 150, 200, 250 Information processing device 52, 152 Communication antenna 54, 154, 202 IC chip 56, 156, 230 Carrier detector 64, 164 Data processing unit 66, 166, 254 Load modulation unit 168 Impedance adjustment unit 232 Power supply switching unit

Claims (8)

A communication antenna for receiving a carrier wave signal of a predetermined frequency transmitted from an external device in a non-contact manner;
A reception detector for detecting reception of the carrier signal at the communication antenna;
A demodulator that demodulates the carrier signal received by the communication antenna;
The carrier wave signal demodulated by the demodulator based on the detection result of the reception detector is subjected to data processing, and a first control signal for controlling load modulation related to a response to the external device according to the processing result; A data processing unit for outputting a second control signal for controlling a change in impedance viewed from the device;
A load modulation unit that selectively performs the load modulation based on the first control signal;
An impedance adjusting unit that selectively switches a connection state between the communication antenna and the data processing unit and changes the impedance based on the second control signal;
An information processing apparatus comprising: A power supply for supplying a driving voltage used by the data processing unit to perform data processing;
A switching unit that selectively supplies the drive voltage to the data processing unit based on a detection result in the reception detection unit;
The information processing apparatus according to claim 1, further comprising: The data processing unit
When the reception detection unit detects reception of the carrier signal, it outputs a first first control signal for connecting the communication antenna and the data processing unit,
When the data processing is completed, a second first control signal for releasing the connection state between the communication antenna and the data processing unit is output and synchronized with the output of the second first control signal. The information processing apparatus according to claim 2, wherein the second control signal is output. The data processing unit
When the data processing is completed, a second first control signal for releasing the connection state between the communication antenna and the data processing unit is output and synchronized with the output of the second first control signal. And outputting the second control signal,
The information processing apparatus according to claim 2, wherein when the output of the second control signal is completed, a first first control signal for setting the communication antenna and the data processing unit in a connected state is output. .   The information processing apparatus according to claim 2, wherein the information processing apparatus is a portable communication apparatus.   The information processing apparatus according to claim 1, wherein the information processing apparatus is an IC card. Receiving a carrier signal of a predetermined frequency transmitted from an external device in a non-contact manner;
Detecting reception of the carrier signal in the receiving step;
Demodulating the carrier signal received in the receiving step;
A first control signal that performs data processing on the carrier signal demodulated in the demodulating step based on a detection result in the detecting step, and controls load modulation related to a response to the external device according to the processing result; Outputting a second control signal for controlling a change in impedance viewed from the external device;
Selectively performing the load modulation based on the first control signal;
Selectively changing an impedance viewed from the external device based on the second control signal;
A communication method. Receiving a carrier signal of a predetermined frequency transmitted from an external device in a contactless manner;
Detecting reception of the carrier signal in the receiving step;
Demodulating the carrier signal received in the receiving step;
A first control signal that performs data processing on the carrier signal demodulated in the demodulating step based on a detection result in the detecting step, and controls load modulation related to a response to the external device according to the processing result; Outputting a second control signal for controlling a change in impedance viewed from the external device;
Selectively performing the load modulation based on the first control signal;
Selectively changing an impedance viewed from the external device based on the second control signal;
A program that causes a computer to execute.

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