JP2013218493A - Reader-writer and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reader-writer having both a reader-writer function and a non-contact IC medium function.SOLUTION: A reader-writer includes: a carrier wave transmission unit 12 for transmitting carrier waves; a carrier wave reception unit for receiving external carrier waves; a first inspection unit 20 for inspecting (detecting) approach of a non-contact IC medium on the basis of an output level of the carrier wave reception unit; and a second inspection unit 21 for inspecting (detecting) approach of an external reader-writer on the basis of an output level of the carrier wave reception unit. When the first inspection unit 20 detects a non-contact IC medium, the reader-writer communicates with the non-contact IC medium. When the second inspection unit 21 detects an external reader-writer, the reader-writer communicates with the external reader-writer.

Description

  The present invention relates to a reader / writer capable of transmitting / receiving information to / from a medium such as a non-contact IC card (non-contact IC medium) and a program for operating the reader / writer.

  Non-contact IC media are widely used as electronic tickets, prepaid cards, personal authentication cards and the like used in transportation. Contactless IC media communicates with a reader / writer via a carrier wave emitted from a reader / writer installed in a ticket gate, commercial facility, store, etc., and executes processing such as settlement (For example, refer to Patent Document 1). There are various forms of non-contact IC media such as an IC card, a mobile phone, and a smartphone.

JP 2007-241538 A

  Such a reader / writer is used as a dedicated device for communicating with a non-contact IC medium, and functions as a reader / writer (a function for communicating with a non-contact IC medium) and a function as a non-contact IC medium (a reader). A reader / writer having a function of communicating with a writer) has not been known.

  Under the above circumstances, the present invention has been made to achieve one or more of the following objects.

  One object of the present invention is to provide a reader / writer having both a function as a reader / writer and a function as a non-contact IC medium.

  Another object of the present invention is to provide a reader / writer that has both a function as a reader / writer and a function as a non-contact IC medium and can reduce power consumption.

  Still another object of the present invention is to provide both a reader / writer function and a non-contact IC medium function as well as a reader / writer capable of detecting the proximity of the reader / writer and / or the non-contact IC medium with high accuracy. Is to provide.

In order to achieve the above object, a reader / writer according to the first aspect of the present invention provides:
A reader / writer capable of performing a reader / writer operation that communicates with a non-contact IC medium and a non-contact IC medium operation that communicates with an external reader / writer,
Carrier transmission means for transmitting a carrier;
Carrier wave receiving means for receiving a carrier wave and outputting a signal having a signal level corresponding to the reception level;
First detection means for detecting the proximity of the non-contact IC medium based on the signal level of the output signal of the carrier wave reception means;
Second detection means for detecting the proximity of the external reader / writer based on the signal level of the output signal of the carrier wave reception means;
Operating means for performing the reader / writer operation when the first detecting means detects the non-contact IC medium, and for performing the non-contact IC medium operation when the second detecting means detects the external reader / writer;
It is characterized by providing.

  An attenuation unit disposed before the first and second detection units, for attenuating the output of the carrier wave reception unit, and an attenuation control unit for controlling the validity / invalidity of the attenuation unit, the attenuation control unit, It is preferable that the attenuating unit is disabled when the first detecting unit detects the proximity of the non-contact IC medium.

  The first detection means detects the proximity of the non-contact IC medium in a state where the transmission of the carrier from the carrier transmission means is turned on, and the second detection means sends out the carrier from the carrier transmission means. It is preferable to detect the proximity of the external reader / writer in the off state.

  Carrier level control means for controlling the output level of the carrier wave sent from the carrier wave sending means is further provided, and the carrier wave level control means outputs the carrier wave sent from the carrier wave sending means during the reader / writer operation. The level is controlled to the first level, and when the proximity of the non-contact IC medium is detected by the first detection unit, the output level of the carrier wave transmitted from the carrier wave transmission unit is set to be higher than the first level. It is preferable to control to a low second level.

  The apparatus further comprises third detection means for detecting the proximity of the external reader / writer by comparing the signal level of the output signal of the carrier wave reception means with a reference voltage, and the second detection means is an output level of the carrier wave reception means. It is preferable that the proximity of the external reader / writer is detected based on the change of.

  Preferably, the first detection unit detects the proximity of the non-contact IC medium when the second detection unit does not detect the proximity of the external reader / writer.

  The operation means controls a CPU (Central Processing Unit) and switching between a power saving state and an operation state of the CPU, and causes the CPU in the power saving state to intermittently shift to the operation state. And the first and / or second detection means is configured to detect the external reader / writer and / or the non-contact IC medium when the power saving state control means shifts the CPU to the operation state. Proximity is detected, and the power saving state control means causes the CPU to save the power saving when the first and / or second detection means does not detect the external reader / writer and / or the non-contact IC medium. It is preferable to shift to a state.

In order to achieve the above object, a program according to the second aspect of the present invention provides:
A computer capable of performing a reader / writer operation that communicates with a non-contact IC medium and a non-contact IC medium operation that communicates with an external reader / writer,
Carrier transmission means for transmitting a carrier;
Carrier wave receiving means for receiving a carrier wave and outputting a signal having a signal level corresponding to the reception level;
First detecting means for detecting the proximity of the non-contact IC medium based on the signal level of the output signal of the carrier wave receiving means;
Second detecting means for detecting the proximity of the external reader / writer based on the signal level of the output signal of the carrier wave receiving means;
An operating means for performing the reader / writer operation when the first detecting means detects the non-contact IC medium, and for performing the non-contact IC medium operation when the second detecting means detects the external reader / writer;
It is made to function as.

It is explanatory drawing which shows the usage condition of the reader / writer which concerns on one Embodiment of this invention. It is explanatory drawing which shows roughly the internal structure of the reader / writer which concerns on one Embodiment of this invention. It is explanatory drawing which shows the example circuit structure of a reader / writer. It is a flowchart which shows the example operation | movement aspect of a reader / writer. 6 is a flowchart illustrating an exemplary contactless IC medium operation. 6 is a flowchart illustrating an exemplary reader / writer operation.

  Hereinafter, a reader / writer according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing a usage mode of a reader / writer 1 according to an embodiment of the present invention.
As shown in the figure, the reader / writer 1 of the present embodiment reads information from the non-contact IC medium 2 and performs non-contact by communicating with the non-contact IC medium 2 when the non-contact IC medium 2 is close to the reader / writer 1. It functions as a reader / writer that writes information into the IC medium 2 and the like. As the non-contact IC medium 2, a non-contact IC card such as an RFID tag, a mobile phone equipped with a non-contact IC chip, a smartphone, or the like can be used.
In addition, when the external reader / writer 3 comes close, the reader / writer 1 communicates with the external reader / writer 3 to transmit the information recorded in the reader / writer 1 to the external reader / writer 3 or to rewrite the information. Functions as a contactless IC medium to perform.

  FIG. 2 is an explanatory diagram schematically showing the internal configuration of the reader / writer 1. FIG. 3 is an explanatory diagram showing an exemplary circuit configuration of the reader / writer 1. Elements corresponding to those in FIG. 2 are denoted by the same reference numerals.

  The reader / writer 1 of this example includes a control unit 11 that controls the operation of the reader / writer 1. The control unit 11 may include a CPU (Central Processing Unit) and a storage device. In addition to executing the following processing, the CPU controls the overall operation of the reader / writer 1. The storage device can be configured by a known storage device such as a ROM, a RAM, a hard disk, or a flash memory, alone or in combination. The control unit 11 may further include a timer having a time measuring function. The timer can be composed of a clock circuit or the like.

  The carrier sending unit 12 sends a carrier for communicating with the non-contact IC medium 2 and the external reader / writer 3. The frequency of the carrier wave can be set to 13.56 MHz, for example.

  The antenna matching unit 13 can be an impedance control circuit for allowing a high frequency such as 13.56 MHz to flow through the antenna 14. The antenna 14 may be a spiral pattern antenna.

  The carrier wave level control unit 15 controls the output level of a carrier wave of 13.56 MHz, for example, sent from the carrier wave sending unit 12. Although the output level may be continuously controlled, the carrier wave level control unit 15 according to the present embodiment controls the output level in two stages: a first level and a second level lower than the first level. .

  The carrier amplitude modulator 16 modulates the amplitude of the carrier. During the reader / writer operation (step S110) described later, the amplitude of the carrier wave transmitted from the carrier wave transmission unit 12 is modulated according to the signal to be transmitted (baseband signal) (ASK (Amplitude Shift Keying) modulation), In the non-contact IC medium operation (step S105) described later, the amplitude of the carrier wave received from the outside is modulated.

  The carrier wave detection / smoothing unit 17 detects and smoothes, for example, a 13.56 MHz carrier wave received by the antenna 14, and constitutes a carrier wave reception unit that outputs a signal having a signal level (voltage) corresponding to the intensity of the received carrier wave. . The carrier wave receiving means may further include an antenna 14 and / or an attenuator 18. By configuring the carrier wave detection / smoothing unit 17 with a diode and a capacitor connected to the ground in the subsequent stage, it is possible to perform envelope detection in an operation close to a positive voltage peak hold. The carrier wave detection / smoothing unit 17 of the present embodiment is shared by the first to third inspection units 20 to 22 and the reception signal amplification unit 23.

  The attenuator 18 attenuates the output of the carrier wave detection / smoothing unit 17 using resistance voltage division or the like. The attenuator 18 can be switched between valid / invalid under the control of the attenuation controller 19. When the invalidity is set, the attenuator 18 outputs the output of the carrier wave detection / smoothing unit 17 as it is without being attenuated. When the validity is set, the attenuator 18 attenuates the output of the carrier wave detection / smoothing unit 17 with a predetermined attenuation rate and outputs the attenuated output. The attenuator 18 of this embodiment also serves as a discharge resistance for envelope detection.

  The first inspection unit (first detection unit) 20 detects the proximity of the non-contact IC medium 2 based on the output level of the carrier wave detection / smoothing unit 17. Although the detection method here is arbitrary, in the present embodiment, the first inspection unit 20 performs A / D conversion on the output of the carrier wave detection / smoothing unit 17, so that the carrier wave transmitted from the carrier wave transmission unit 12 is output. The level is monitored, and the proximity of the non-contact IC medium 2 is determined based on a change in the carrier level, for example, that the carrier level has changed more than a certain level within a predetermined period, or that the change has continued for more than a certain time. . Since the output level of the carrier wave detection / smoothing unit 17 reacts to a metal body such as a resonance circuit of a non-contact IC card, a mobile phone, or a smartphone, any of these can be detected.

  The second inspection unit (second detection unit) 21 detects the proximity of the external reader / writer 3 based on the output level of the carrier wave detection / smoothing unit 17. Although the detection method here is arbitrary, in the present embodiment, the second inspection unit 21 performs A / D conversion on the output of the carrier wave detection / smoothing unit 17, and thereby the level of the external carrier wave from the external reader / writer 3. And the proximity of the external reader / writer 3 is determined by the change of the external carrier level.

  The 1st, 2nd test | inspection parts 20 and 21 can have an A / D conversion means for performing said A / D conversion. In this case, the first and second inspection units 20 and 21 may share a single A / D conversion unit or may include individual A / D conversion units.

  Although the first and second inspection units 20 and 21 of the present embodiment require a program operation by the CPU, since the determination is based on multiple values, it is possible to detect a non-contact IC medium and an external reader / writer with high accuracy. Is possible.

  The third inspection unit (third detection unit) 22 detects the proximity of the external reader / writer 3 by comparing the output of the carrier wave detection / smoothing unit 17 with a relatively high reference voltage. Since the third inspection unit 22 does not require a program operation, the external reader / writer 3 can be detected even when the CPU is in a power saving state. However, since the determination is based on binary values, the sensitivity is higher than that of the second inspection unit 21. Low.

  The reception signal amplification unit 23 reads information contained in the carrier wave by amplifying the output of the carrier wave detection / smoothing unit 17. When receiving a carrier wave, it is possible to perform efficient envelope detection by enabling the attenuator 18 and reducing the discharge resistance of the carrier wave detection / smoothing unit 17.

  The external carrier clock recovery unit 24 generates a clock by shaping the waveform of the external carrier by the external reader / writer 3. The generated clock is used as a synchronous clock when communicating with the external reader / writer.

  The power controller 25 dynamically controls on / off of the power of the received signal amplifier 23, the external carrier clock recovery unit 24, and the like.

  The functions of the carrier level control unit 15, the carrier amplitude modulation unit 16, the attenuation control unit 19, the first and second inspection units 20 and 21, etc. can be incorporated into the control unit 11.

  FIG. 4 is a flowchart showing an exemplary operation mode of the reader / writer 1 according to the present embodiment. Here, it is assumed that the CPU is in the power saving state in the initial state (step S101).

  In step S101, the CPU is in a power saving state, the output of the carrier wave sending unit 12 is turned off, and the attenuator 18 is effectively switched.

  In steps S102 and 103, processing for periodically shifting the CPU to the operating state is executed. That is, in step S102, it is determined whether or not a predetermined time has elapsed. When the predetermined time has elapsed, the process proceeds to step S103, and the CPU shifts to an operating state.

  In subsequent step S104, the second inspection unit 21 monitors the level of the carrier wave received by the carrier wave detection / smoothing unit 17, and inspects (detects) the proximity of the external reader / writer 3 based on a change in the external carrier wave level. At this time, the output of the carrier wave transmission unit 12 is turned off, and the attenuator 18 is effectively maintained.

  If the external reader / writer 3 is detected in step S104 (Yes), the process proceeds to step S105, and a non-contact IC medium operation for communicating with the external reader / writer 3 is executed. The third inspection unit 22 can detect the proximity of the external reader / writer 3 even when the CPU is in the power saving state (step S101). In step S101, the third inspection unit 22 detects the proximity of the external reader / writer 3. Also when it detects, a process transfers to step S105.

  If the external reader / writer 3 is not detected in step S104 (No), the attenuator 18 is switched to invalid by the attenuation controller 19 in step S106, and in step S107, the carrier is transmitted from the carrier transmitter 12. Is switched on. At this time, the carrier wave level control unit 15 controls the output level of the carrier wave to a relatively low second level.

  In subsequent step S108, the first inspection unit 20 monitors the level of the carrier wave received by the carrier wave detection / smoothing unit 17, and inspects (detects) the proximity of the non-contact IC medium 2 by a change in the carrier wave level.

  As described above, in the inspection (detection) in step S108, a relatively low second level carrier wave is used, so that it is possible to reduce power consumption related to detection of the non-contact IC medium 2. Further, the lower the carrier level, the narrower the dynamic range of the input signal to the first inspection unit, but the input signal dynamic range is improved by disabling the attenuator 18 (step S106).

  When the non-contact IC medium 2 is detected in step S108 (Yes), the process proceeds to step S110 after the attenuator 18 is effectively switched in step S109, and the reader communicates with the non-contact IC medium 2 The writer operation is executed.

  If the non-contact IC medium 2 is not detected in step S108 (No), after the attenuator 18 is effectively switched in step S111, the process proceeds to step S101, and the CPU enters a power saving state.

  FIG. 5 is a flowchart showing an exemplary non-contact IC medium operation (step S105) executed in the reader / writer 1.

  When the non-contact IC medium operation is started, reception of a command from the external reader / writer 3 is awaited for a predetermined time in step S201. If the command is not received within a predetermined time (No), the proximity of the external reader / writer 3 is inspected (detected) by the second inspection means in step S202, and the external reader / writer 3 is detected. If (Yes), step S201 is executed again and if not detected (No), the CPU enters a power saving state (step S101).

  When a command from the external reader / writer 3 is received in step S201 (Yes), processing corresponding to the command such as response transmission is executed in step S203. When the process of step S203 is completed, the CPU enters a power saving state (step S101).

  While the non-contact IC medium operation is being executed (steps S201 to S203), the attenuator 18 is maintained valid, and the output of the carrier wave sending unit 12 is turned off.

  FIG. 6 is a flowchart showing an exemplary reader / writer operation (step S110) executed in the reader / writer 1.

  When the reader / writer operation starts, when a polling command is transmitted from the carrier wave sending unit 12 for a predetermined time in step S301 and a response is received from the non-contact IC medium 2, and no response is received. In (No), the CPU enters a power saving state (step S101).

  If a response from the non-contact IC medium 2 is received in step S301 (Yes), processing such as sending a command other than polling and receiving a response from the non-contact IC medium 2 is executed in step S302. Is done. When the communication with the non-contact IC medium 2 in step S302 is completed, or when the response from the non-contact IC medium 2 has not exceeded the predetermined time, the CPU enters a power saving state (step S101).

  During the execution of the reader / writer operation (steps S301 and S302), the attenuator 18 is effectively maintained, and the level of the carrier wave sent from the carrier wave sending unit 12 is set to the first level higher than the second level. .

  As described above, in the reader / writer 1 according to the embodiment of the present invention, when the first inspection unit 20 detects the non-contact IC medium 2, the reader / writer operation is performed, and the second inspection unit 21 detects the external reader / writer 3. In this case, since the non-contact IC medium operation is performed, a reader / writer having both a function as a reader / writer and a function as a non-contact IC medium can be realized.

  Further, the reader / writer 1 according to the embodiment of the present invention includes the attenuator 18 for attenuating the output of the carrier wave detection / smoothing unit 17, so that the first inspection unit is detected by the carrier wave from the carrier wave detection / smoothing unit 17 or the external reader / writer 3. 20 and / or application of an overvoltage to the second inspection unit 21 can be prevented. The attenuator 18 is particularly useful when, for example, the first and second inspection units 20 and 21 have A / D conversion means for A / D converting the output of the carrier wave detection / smoothing unit 17.

  Further, in the reader / writer 1 according to the embodiment of the present invention, when the first inspection unit 20 inspects (detects) the proximity of the non-contact ID medium 2, the attenuation control unit 19 controls the attenuator 18 to be invalid. Therefore, the dynamic range of the input signal to the first inspection unit 20 can be improved. This is particularly useful when the output level of the carrier wave transmitted by the carrier wave transmission unit 12 is lowered in the proximity inspection (detection) of the non-contact IC medium 2 in order to save power.

  Further, in the reader / writer 1 according to the embodiment of the present invention, the first inspection unit 20 inspects (detects) the proximity of the non-contact IC medium 2 with the transmission of the carrier wave from the carrier wave transmission unit 12 turned on, The second inspection unit 21 inspects (detects) the proximity of the external reader / writer 3 with the transmission of the carrier wave from the carrier wave transmission unit 12 turned off. Therefore, since the carrier wave from the carrier wave sending unit 12 is sent only when the proximity of the non-contact IC medium 2 is inspected (detected), the power consumption can be reduced.

  In addition, the reader / writer 1 according to the embodiment of the present invention includes a carrier level control unit 15 that controls the output level of the carrier transmitted from the carrier transmission unit 12. The carrier level control unit 15 controls the output level of the carrier transmitted from the carrier transmission unit 12 to the first level during the reader / writer operation, and the non-contact IC medium 2 by the first inspection unit 20 is controlled. In the proximity inspection (detection), the output level of the carrier wave sent from the carrier wave sending unit 12 is controlled to a second level lower than the first level. Therefore, the output level of the carrier wave transmitted by the carrier wave sending unit 12 during the proximity inspection (detection) of the non-contact IC medium 2 is controlled to the second level lower than the first level in the reader / writer operation. As a result, the power consumption can be further reduced.

  The reader / writer 1 according to the embodiment of the present invention further includes a third inspection unit 22 that inspects (detects) the proximity of the external reader / writer 3 by comparing the output level of the carrier wave detection / smoothing unit 17 with a reference voltage. The second inspection unit 21 inspects (detects) the proximity of the external reader / writer 3 based on the change in the output level of the carrier wave detection / smoothing unit 17. Accordingly, since the second inspection unit 21 inspects (detects) the proximity of the external reader / writer 3 based on the change in the output level of the carrier wave detection / smoothing unit 17, it is possible to detect the external reader / writer 3 with high accuracy. It becomes. On the other hand, since the third inspection unit 22 compares the output of the carrier wave detection / smoothing unit 17 with a reference voltage, a program operation is not necessary. Therefore, the sensitivity is lower than that of the second inspection unit 21 that performs inspection (detection) by monitoring the change in the output level of the carrier wave detection / smoothing unit 17, but the proximity of the external reader / writer 3 is maintained even when the CPU is in a power saving state. Inspection (detection) can be performed. By using the second and third inspection units 21 and 22 in combination, the present invention can achieve further power saving and / or improved detection accuracy.

  In addition, the reader / writer 1 according to the embodiment of the present invention includes a power saving state control unit that controls switching between a power saving state and an operation state of the CPU and intermittently shifts the CPU in the power saving state to the operation state. The first and / or second inspection units 20 and 21 inspect (detect) the proximity of the external reader / writer 3 and / or the non-contact IC medium 2 when the power saving state control means shifts the CPU to the operating state. The power saving state control means shifts the CPU to the power saving state when the first and / or second inspection unit 20, 21 does not detect the external reader / writer 3 and / or the non-contact IC medium 2. Let Accordingly, since the CPU is switched to the operating state only when the proximity of the non-contact IC medium 2 and / or the external reader / writer 3 is inspected (detected), the power consumption by the CPU can be reduced.

  As mentioned above, although this invention was demonstrated by preferable embodiment, this invention is not limited to these embodiment, It can change arbitrarily in a claim. For example, arbitrary configurations in each embodiment can be omitted as appropriate, or a part or all of the configurations in one embodiment can be added to other embodiments.

  The “non-contact IC medium” in this specification means a medium that can read and write information by communicating with a reader / writer by an electromagnetic induction method. The form of the non-contact IC medium is arbitrary such as an IC card, a mobile phone, and a smartphone.

  In addition, the “reader / writer” in this specification means a device capable of reading and writing information on a non-contact IC medium by communicating with the non-contact IC medium by an electromagnetic induction method.

  In addition, the “reader / writer” of the present invention can be configured by a stationary device, or can be configured by a portable device such as a mobile phone, a smartphone, or a PDA (Personal Digital Assistant). is there.

  In addition, by applying an operation program that defines the operation of the reader / writer 1 according to the present invention to an existing personal computer, information terminal device, or the like, the personal computer or the like can also function as the reader / writer 1 according to the present invention. It is.

  Further, the distribution method of such a program is arbitrary. For example, the program can be read by a computer such as a CD-ROM (Compact Disk Read-Only Memory), a DVD (Digital Versatile Disk), an MO (Magneto Optical Disk), or a memory card. It may be distributed by storing in a recording medium, or distributed via a communication network such as the Internet.

DESCRIPTION OF SYMBOLS 1 ... Reader / writer 2 ... Non-contact IC medium 3 ... External reader / writer 11 ... Control part 12 ... Carrier wave transmission part 13 ... Antenna matching part 14 ... Antenna 15 ... Carrier level control unit 16 Carrier amplitude modulation unit 17 Carrier detection smoothing unit 18 Attenuator 19 Attenuation control unit 20 First inspection unit 21 Second inspection unit 22 ... third inspection unit 23 ... received signal amplification unit 24 ... external carrier clock recovery unit 25 ... power supply control unit

Claims (8)

A reader / writer capable of performing a reader / writer operation that communicates with a non-contact IC medium and a non-contact IC medium operation that communicates with an external reader / writer,
Carrier transmission means for transmitting a carrier;
Carrier wave receiving means for receiving a carrier wave and outputting a signal having a signal level corresponding to the reception level;
First detection means for detecting the proximity of the non-contact IC medium based on the signal level of the output signal of the carrier wave reception means;
Second detection means for detecting the proximity of the external reader / writer based on the signal level of the output signal of the carrier wave reception means;
Operating means for performing the reader / writer operation when the first detecting means detects the non-contact IC medium, and for performing the non-contact IC medium operation when the second detecting means detects the external reader / writer;
A reader / writer characterized by comprising: Attenuating means disposed in a preceding stage of the first and second detecting means, for attenuating the output of the carrier wave receiving means;
Further comprising attenuation control means for controlling validity / invalidity of the attenuation means;
The attenuation control means invalidates the attenuation means when the first detection means detects the proximity of the non-contact IC medium;
The reader / writer according to claim 1. The first detection means detects the proximity of the non-contact IC medium in a state where the transmission of the carrier wave from the carrier wave sending means is turned on,
The second detection means detects the proximity of the external reader / writer in a state where the transmission of the carrier from the carrier transmission means is turned off.
The reader / writer according to claim 1, wherein the reader / writer is provided. Carrier level control means for controlling the output level of the carrier wave sent from the carrier wave sending means,
The carrier level control means includes
During the reader / writer operation, the output level of the carrier wave sent from the carrier wave sending means is controlled to the first level,
When the proximity of the non-contact IC medium is detected by the first detection means, the output level of the carrier wave sent from the carrier wave sending means is controlled to a second level lower than the first level;
The reader / writer according to claim 3. Further comprising third detection means for detecting the proximity of the external reader / writer by comparing the signal level of the output signal of the carrier wave receiving means with a reference voltage;
The second detection means detects the proximity of the external reader / writer based on a change in the output level of the carrier wave reception means;
The reader / writer according to any one of claims 1 to 4, wherein: The first detection means detects the proximity of the non-contact IC medium when the second detection means does not detect the proximity of the external reader / writer.
The reader / writer according to any one of claims 1 to 5, wherein: The operating means includes
CPU (Central Processing Unit)
A power saving state control means for controlling switching between the power saving state and the operating state of the CPU and intermittently shifting the CPU in the power saving state to the operating state;
The first and / or second detection means detects the proximity of the external reader / writer and / or the non-contact IC medium when the power saving state control means shifts the CPU to the operation state,
The power saving state control means shifts the CPU to the power saving state when the external reader / writer and / or the non-contact IC medium are not detected by the first and / or second detection means.
The reader / writer according to claim 1, wherein: A computer capable of performing a reader / writer operation that communicates with a non-contact IC medium and a non-contact IC medium operation that communicates with an external reader / writer,
Carrier transmission means for transmitting a carrier;
Carrier wave receiving means for receiving a carrier wave and outputting a signal having a signal level corresponding to the reception level;
First detecting means for detecting the proximity of the non-contact IC medium based on the signal level of the output signal of the carrier wave receiving means;
Second detecting means for detecting the proximity of the external reader / writer based on the signal level of the output signal of the carrier wave receiving means;
An operating means for performing the reader / writer operation when the first detecting means detects the non-contact IC medium, and for performing the non-contact IC medium operation when the second detecting means detects the external reader / writer;
A program characterized by functioning as

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