JP2008011198A - Radio communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication apparatus which can acquire good communication characteristics with respect to any radio communication medium. <P>SOLUTION: When a contactless IC card enters a communication available area, information inherent to the contactless IC card (ID information) is acquired from the IC card. Subject to the occurrence of a communication unavailable state, the type of the contactless IC card is determined based on the inherent information of the contactless IC card. Based on the decision results, the characteristics (resonant frequency and Q value of a resonant circuit) of communication with the contactless IC card are optimized. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is applied to, for example, a contactless IC card (wireless communication medium) driven by electric power induced by electromagnetic inductive coupling and a contactless IC card reader / writer that transmits and receives data without contact (wireless communication). It is related with a suitable radio communication apparatus.

Generally, this type of non-contact IC card reader / writer is connected to a host device, and this host device sends a command related to data transmission / reception to the non-contact IC card reader / writer, and from the non-contact IC card reader / writer. A result of communication with a non-contact IC card is received.
The non-contact IC card reader / writer sends an ASK (amplitude shift) modulation signal of a predetermined frequency from the loop antenna to communicate with the non-contact IC card, and the non-contact IC card can communicate with the non-contact IC card reader / writer. When entering the area, operation power is supplied to the non-contact IC card by electromagnetic induction coupling generated between the loop antenna of the non-contact IC card reader / writer and the loop antenna of the non-contact IC card. The non-contact IC card responds to the received data by load modulation, and the non-contact IC card reader / writer detects the load modulation data by envelope detection and demodulates it by the demodulation circuit, and the demodulated data is sent to the host device. It is transferred (for example, see Patent Document 1).
JP-A-10-187916

  Currently, printing companies and electrical manufacturers manufacture and sell non-contact IC cards, but each has different communication characteristics, so it has optimal communication characteristics for all non-contact IC cards. Thus, it is impossible to adjust the communication characteristics of the non-contact IC card reader / writer in advance. For this reason, in order to adjust the communication characteristics to be optimal for a specific non-contact IC card, there is a problem that communication performance with other non-contact IC cards must be sacrificed to some extent.

  Accordingly, an object of the present invention is to provide a wireless communication apparatus that can obtain good communication characteristics for any wireless communication medium.

  The wireless communication device of the present invention has an antenna for performing wireless communication using an electromagnetic wave with a wireless communication medium, and performs data communication with the wireless communication medium via this antenna. In a wireless communication apparatus that performs transmission and reception, when a wireless communication medium enters a communicable area, unique information is acquired from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna. After obtaining the unique information by the information obtaining means, the unique information obtaining means, the communication state monitoring means for monitoring the communication state with the wireless communication medium, and the communication state monitoring means does not communicate with the wireless communication medium. When it is detected that the wireless communication medium is enabled, the type of the wireless communication medium is determined based on the unique information acquired by the unique information acquisition unit. Hazuki and a communication characteristic adjusting means for adjusting the communication characteristics between the wireless communication medium to an optimum value.

  The wireless communication device of the present invention has an antenna for performing wireless communication using electromagnetic waves with a wireless communication medium, and performs wireless communication with the wireless communication medium via this antenna. In a wireless communication apparatus that transmits and receives data, when a wireless communication medium enters a communicable area, unique information is acquired from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna. Specific information acquisition means, a communication status monitoring means for monitoring the communication status with the wireless communication medium after acquiring the specific information by the specific information acquisition means, and communication with the wireless communication medium by the communication status monitoring means. When it is detected that the wireless communication medium becomes impossible, the type of the wireless communication medium is determined based on the specific information acquired by the specific information acquisition means. And comprising an antenna output adjusting means for adjusting to an optimum value the output level of the antenna based on the results.

  According to the present invention, when the wireless communication medium enters the communicable region, the unique information is acquired from the wireless communication medium, and the wireless communication medium is acquired based on the unique information of the wireless communication medium on condition that an incommunicable state occurs. A wireless communication apparatus capable of obtaining good communication characteristics for any wireless communication medium by determining the type of communication medium and optimizing the communication characteristics with the wireless communication medium based on the determination result Can be provided.

  Further, according to the present invention, when the wireless communication medium enters the communicable area, the unique information is acquired from the wireless communication medium, and based on the unique information of the wireless communication medium on condition that the communication impossible state occurs. By determining the type of the wireless communication medium and optimizing the antenna output level based on the determination result, it is possible to provide a wireless communication apparatus that can obtain good communication characteristics for any wireless communication medium.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 schematically shows the configuration of a non-contact IC card reader / writer as a wireless communication apparatus according to the first embodiment. This non-contact IC card reader / writer is an example in which wireless communication using electromagnetic waves is performed with the non-contact IC card by placing a non-contact IC card as a wireless communication medium on the antenna unit. Show.

  In FIG. 1, a non-contact IC card reader / writer 1 is connected to a host device 2 that performs command transmission and response processing, and the non-contact IC card 3 is inserted into the antenna unit, so that the non-contact IC card 3 Are configured to perform data transmission / reception such as data reading and writing.

  The non-contact IC card reader / writer 1 includes an antenna (for example, a loop antenna) 11 for performing radio communication using electromagnetic waves with the non-contact IC card 3, a resonance circuit 12 including the antenna 11, and a resonance circuit 12. A transmission / reception circuit 13 for transmitting / receiving to / from the non-contact IC card 3, a CPU (central processing unit) 14 as a control means for performing overall control, and transmission / reception using externally supplied power as an operation power source The power supply circuit 15 is supplied to the circuit 13 and the CPU 14.

  The resonance circuit 12 is controlled to switch the circuit constants (resonance frequency, quality factor (Q value)) by the resonance circuit constant control signals b0, b1, b2, and b3 supplied from the CPU 14, so that the non-contact IC card 3 and The communication characteristics are adjusted to the optimum location, which will be described in detail later.

  The CPU 14 is provided with a memory 16 such as a ROM or an EEPROM. For example, data in the format shown in FIG. 2 is stored in the memory 16 in advance, and resonance circuit constant control signals b0, b1, b2, b3 from the determined type of the non-contact IC card 3 to the resonance circuit 12 are stored. The bit pattern is determined.

  That is, in the memory 16, as shown in FIG. 2, the resonance circuit constant control signals b0 and b1 for each type of the non-contact IC card 3 processed by the non-contact IC card reader / writer 1 (for example, cards A to D). , B2 and b3 are previously stored.

  For example, as shown in FIG. 3, the resonance circuit 12 includes an antenna 11, a plurality (two in this example) of capacitors C <b> 1 to C <b> 2 and resistors R <b> 1 to R <b> 2 connected in parallel to the antenna 11, and the plurality of capacitors C <b> 1 to C <b> 1. A plurality of (four in this example) transistors T1 to T4 as switch means connected in series to C2 and resistors R1 to R2 are provided, and the plurality of transistors T1 to T4 are connected to a resonance circuit constant from the CPU 14. The control signals b0 to b3 are selectively turned on and off.

  The plurality of capacitors C1 to C2 are for switching and setting the resonance frequency of the resonance circuit 12 to a desired value. Each of the capacitors C1 and C2 has a different predetermined value (capacitance), for example, a value at which the resonance frequency changes at equal intervals. And a desired capacitor (resonance frequency) is selected by selectively turning on and off the plurality of transistors T1 to T2 by the resonance circuit constant control signals b0 to b1.

  The plurality of resistors R1 to R2 are for switching and setting the Q value of the resonance circuit 12 to a desired value, and different predetermined values (resistance values), for example, Q values change at equal intervals. The desired resistance (Q value) is selected by selectively turning on and off the plurality of transistors T3 to T4 by the resonance circuit constant control signals b2 to b3. .

  The number of resonant circuit constant control signals and the number of capacitors and resistors are not limited to the above example, and may be larger. As the number increases, finer and more accurate constant control becomes possible.

  The non-contact IC card 3 has a card manufacturing ID stored in advance in the built-in memory as information unique to the card, and transmits the card manufacturing ID as a response to the polling command from the non-contact IC card reader / writer 1. And The card manufacturing ID includes information such as a manufacturer code, a manufacturing device code, a manufacturing date, and a manufacturing serial number.

Next, the operation of the non-contact IC card reader / writer 1 according to the first embodiment in such a configuration will be described with reference to the flowchart shown in FIG. 4 and the conceptual diagram of the operation shown in FIG.
The CPU 14 of the non-contact IC card reader / writer 1 periodically transmits a polling command and waits for the non-contact IC card 3 to approach (step S1). Here, when the non-contact IC card 3 enters the communicable area E1, the response including the card manufacturing ID and the manufacturing parameters transmitted from the non-contact IC card 3 that has received the polling command is sent to the non-contact IC card reader / writer 1. CPU 14 receives (step S2).

  Thereafter, the CPU 14 of the non-contact IC card reader / writer 1 performs mutual authentication and data reading / writing with the non-contact IC card 3 (step S3). Here, the communication of the non-contact IC card reader / writer 1 is performed. When the characteristics are not optimized for the non-contact IC card 3, a non-communication area (null area) E2 is generated in the communicable area E1 as shown in FIG.

  When the non-contact IC card 3 approaches the antenna 11 of the non-contact IC card reader / writer 1 and enters the null area E2, a command response timeout occurs in mutual authentication and data reading or writing.

  Therefore, the CPU 14 of the non-contact IC card reader / writer 1 first checks whether or not a response timeout has occurred during communication for mutual authentication (step S4). The type of the non-contact IC card 3 is determined from a certain card manufacturing ID, and the resonance frequency and Q value of the resonance circuit 12 are adjusted to optimum values based on the determination result (step S5).

  That is, data in the format as shown in FIG. 2 is stored in the memory 16 in the CPU 14 in advance, and by referring to this data, from the determined type of the non-contact IC card 3 to the resonance circuit 12 is stored. The bit pattern of the resonance circuit constant control signals b2 to b3 is determined. Here, for example, when the card A approaches, the resonance circuit constant control signal is b0 = 0, b1-b3 = 1 from the data of FIG. 2, and b0 = 0, b1-b3 = 1 in the example of FIG. By turning off the transistor T1 and turning on the transistors T2 to T4, the circuit constants are switched to adjust the resonance frequency and Q value of the resonance circuit 12 to optimum values for the card A.

  Thereafter, the CPU 14 returns to step S3, retransmits the command that has caused a response timeout to the non-contact IC card 3, and performs communication again. Here, the CPU 14 checks again whether or not a response timeout has occurred (step S4). If a response timeout has occurred, the CPU 14 repeats the same processing again (step S5).

  If no response time-out has occurred in step S4, the CPU 14 next reads or writes data (step S6), but checks whether or not a response time-out has occurred during this communication (step S7). ) If a response timeout occurs, the same processing as in step S5 is performed (step S8).

Thereafter, the CPU 14 returns to step S6, retransmits the command that has caused a response timeout to the non-contact IC card 3, and performs communication again. Here, the CPU 14 checks whether or not a response timeout has occurred again (step S7). If a response timeout has occurred, the CPU 14 repeats the same process again (step S8).
If no response timeout has occurred in step S <b> 7, the CPU 14 ends the data transmission / reception process with the non-contact IC card 3.

  As described above, according to the first embodiment, the type of the non-contact IC card 3 approaching from the card manufacturing ID that is the card specific information acquired as a response to the polling command is determined, and the non-contact IC card 3 By optimizing the resonance frequency and Q value of the resonance circuit 12 for each card at the time of entering the null region E2, the communication characteristics of the non-contact IC card reader / writer 1 are optimized for each non-contact IC card 3, Good communication characteristics can be obtained for any card.

Next, a second embodiment will be described.
Since the configuration of the non-contact IC card reader / writer according to the second embodiment is the same as that of the first embodiment described above, the description thereof is omitted.

The operation of the non-contact IC card reader / writer 1 according to the second embodiment will be described below with reference to the flowchart shown in FIG. 6 and the conceptual diagram of the operation shown in FIG.
As in the first embodiment, the CPU 14 of the non-contact IC card reader / writer 1 periodically transmits a polling command and waits for the non-contact IC card 3 to approach (step S11). Here, when the non-contact IC card 3 enters the communicable area E1, the response including the card manufacturing ID and the manufacturing parameters transmitted from the non-contact IC card 3 that has received the polling command is sent to the non-contact IC card reader / writer 1. The CPU 14 receives (step S12).

Next, as in the first embodiment, the CPU 14 of the non-contact IC card reader / writer 1 discriminates the type of the non-contact IC card 3 from the previously obtained card manufacturing ID, and based on the discrimination result, the resonance circuit. 12 resonance frequencies and Q values are adjusted to optimum values (step S13).
Next, the CPU 14 of the non-contact IC card reader / writer 1 performs mutual authentication and data reading or writing with the non-contact IC card 3 (step S14).

  As described above, according to the second embodiment, the non-contact IC is optimized by optimizing the resonance frequency and the Q value of the resonance circuit 12 for each card at the time when the card manufacturing ID which is the card specific information is received. Even when the communication characteristics of the non-contact IC card reader / writer 1 are not optimized for the card 3, the communication characteristics can be optimized before the non-contact IC card 3 enters the null area E2.

Next, a third embodiment will be described.
FIG. 8 schematically shows a configuration of a non-contact IC card reader / writer as a wireless communication apparatus according to the third embodiment. The third embodiment is different from the first embodiment in that there is no means for controlling the circuit constants of the resonance circuit 12. Instead, the power supply circuit 15 is controlled by a power supply circuit control signal supplied from the CPU 14. The power supply voltage supplied to the transmission / reception circuit 13 is controlled. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

In the third embodiment, the memory 16 stores, for example, data in a format as shown in FIG. 9 in advance, and the power supply voltage to the transmission / reception circuit 13 is determined from the determined type of the non-contact IC card 3. It comes to decide.
That is, in the memory 16, as shown in FIG. 9, the power supply voltage supplied to the transmission / reception circuit 13 for each type of the non-contact IC card 3 processed by the non-contact IC card reader / writer 1 (for example, cards A to D). Is stored in advance.

Next, the operation of the non-contact IC card reader / writer 1 according to the third embodiment in such a configuration will be described with reference to the flowchart shown in FIG.
The CPU 14 of the non-contact IC card reader / writer 1 periodically transmits a polling command and waits for the non-contact IC card 3 to approach (step S21). Here, when the non-contact IC card 3 enters the communicable area E1, the response including the card manufacturing ID and the manufacturing parameters transmitted from the non-contact IC card 3 that has received the polling command is sent to the non-contact IC card reader / writer 1. The CPU 14 receives (step S22).

  Thereafter, the CPU 14 of the non-contact IC card reader / writer 1 performs mutual authentication and reading / writing of data with the non-contact IC card 3 (step S23). When the output level is not optimized for the non-contact IC card 3, a non-communication area (null area) E2 occurs in the communicable area E1.

  When the non-contact IC card 3 approaches the antenna 11 of the non-contact IC card reader / writer 1 and enters the null area E2, a command response timeout occurs in mutual authentication and data reading or writing.

  Therefore, the CPU 14 of the non-contact IC card reader / writer 1 first checks whether or not a response timeout has occurred during communication for mutual authentication (step S24). The type of the non-contact IC card 3 is determined from a certain card manufacturing ID, and the power supply voltage to the transmission / reception circuit 13 is determined based on the determination result, thereby adjusting the output level of the antenna 11 to the optimum value (step S25). ).

  That is, data in a format as shown in FIG. 9 is stored in advance in the memory 16 in the CPU 14, and by referring to this data, the optimum type for each card is determined based on the type of the non-contact IC card 3 determined. The power supply voltage to the transmission / reception circuit 13 is determined. Here, for example, when the card A approaches, the supply power supply voltage from the data in FIG. 9 to the transmission / reception circuit 13 becomes 5 volts (V), and the output level of the antenna 11 is adjusted to an optimum value with respect to the card A. .

  Thereafter, the CPU 14 returns to step S23, retransmits the command that has caused a response timeout to the non-contact IC card 3, and performs communication again. Here, the CPU 14 checks whether or not a response timeout has occurred again (step S24). If a response timeout has occurred, the CPU 14 repeats the same process again (step S25).

  If no response time-out has occurred in step S24, the CPU 14 next reads or writes data (step S26), but checks whether or not a response time-out has occurred during this communication (step S27). ) If a response timeout occurs, the same processing as in step S25 is performed (step S28).

Thereafter, the CPU 14 returns to step S26, retransmits the command that has caused a response timeout to the non-contact IC card 3, and performs communication again. Here, the CPU 14 checks whether or not a response timeout has occurred again (step S27). If a response timeout has occurred, the CPU 14 repeats the same process again (step S28).
If no response timeout has occurred in step S <b> 27, the CPU 14 ends the data transmission / reception process with the non-contact IC card 3.

  As described above, according to the third embodiment, when the contactless IC card 3 enters the null area E2, the output level of the antenna 11 is optimized for each card based on the card manufacturing ID. By optimizing the communication characteristics of the non-contact IC card reader / writer 1 for each non-contact IC card 3, good communication characteristics can be obtained for any card.

Next, a fourth embodiment will be described.
Since the configuration of the non-contact IC card reader / writer according to the fourth embodiment is the same as that of the third embodiment described above, description thereof is omitted.

The operation of the non-contact IC card reader / writer 1 according to the fourth embodiment will be described below with reference to the flowchart shown in FIG.
As in the third embodiment, the CPU 14 of the non-contact IC card reader / writer 1 periodically transmits a polling command and waits for the non-contact IC card 3 to approach (step S31). Here, when the non-contact IC card 3 enters the communicable area E1, the response including the card manufacturing ID and the manufacturing parameters transmitted from the non-contact IC card 3 that has received the polling command is sent to the non-contact IC card reader / writer 1. CPU 14 receives (step S32).

Next, as in the third embodiment, the CPU 14 of the non-contact IC card reader / writer 1 discriminates the type of the non-contact IC card 3 from the previously obtained card manufacturing ID, and based on the discrimination result, a transmission / reception circuit. By determining the supply power supply voltage to 13, the output level of the antenna 11 is adjusted to the optimum value (step S33).
Next, the CPU 14 of the non-contact IC card reader / writer 1 performs mutual authentication and data reading or writing with the non-contact IC card 3 (step S34).

  As described above, according to the fourth embodiment, by optimizing the output level of the antenna 11 for each card at the time of obtaining the card manufacturing ID that is card specific information, Even when the communication characteristics of the non-contact IC card reader / writer 1 are not optimized, the communication characteristics can be optimized before the non-contact IC card 3 enters the null area E2.

  In the first and second embodiments, the case where the communication characteristics are optimized by controlling the resonance frequency and the Q value of the resonance circuit 12 has been described. However, the present invention is not limited to this. Instead, the communication characteristics may be optimized by controlling at least one of the resonance frequency and the Q value.

1 is a block diagram schematically showing a configuration of a non-contact IC card reader / writer as a wireless communication device according to first and second embodiments of the present invention. The figure which shows the example of data stored in the memory incorporated in CPU which concerns on 1st, 2nd embodiment. The schematic diagram which shows roughly the structure of the resonance circuit which concerns on 1st, 2nd embodiment. The flowchart explaining operation | movement of the non-contact IC card reader / writer which concerns on 1st Embodiment. The conceptual diagram of the operation | movement explaining operation | movement of the non-contact IC card reader / writer which concerns on 1st Embodiment. The flowchart explaining operation | movement of the non-contact IC card reader / writer based on 2nd Embodiment. The conceptual diagram of the operation | movement explaining operation | movement of the non-contact IC card reader / writer based on 2nd Embodiment. The block diagram which shows schematically the structure of the non-contact IC card reader / writer as a radio | wireless communication apparatus which concerns on the 3rd, 4th embodiment of this invention. The figure which shows the example of data stored in the memory incorporated in CPU which concerns on 3rd, 4th embodiment. The flowchart explaining operation | movement of the non-contact IC card reader / writer based on 3rd Embodiment. The flowchart explaining operation | movement of the non-contact IC card reader / writer based on 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Non-contact IC card reader / writer (wireless communication device), 2 ... Host device, 3 ... Non-contact IC card (wireless communication medium), 11 ... Antenna, 12 ... Resonance circuit, 13 ... Transmission / reception circuit, 14 ... CPU (control) Means), 15... Power supply circuit, 16... Memory (storage means), E1... Communicable area, E2.

Claims (6)

In a wireless communication apparatus having an antenna for performing wireless communication using electromagnetic waves with a wireless communication medium, and performing data transmission / reception by performing wireless communication with the wireless communication medium via the antenna,
When a wireless communication medium enters a communicable region, unique information acquisition means for acquiring unique information from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna;
A communication state monitoring unit for monitoring a communication state with the wireless communication medium after acquiring the specific information by the specific information acquisition unit;
When the communication state monitoring unit detects that communication with the wireless communication medium is impossible, the type of the wireless communication medium is determined based on the unique information acquired by the unique information acquisition unit, Communication characteristic adjusting means for adjusting the communication characteristic with the wireless communication medium to an optimum value based on the determination result;
A wireless communication apparatus comprising: In a wireless communication apparatus having an antenna for performing wireless communication using electromagnetic waves with a wireless communication medium, and performing data transmission / reception by performing wireless communication with the wireless communication medium via the antenna,
When a wireless communication medium enters a communicable region, unique information acquisition means for acquiring unique information from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna;
A communication characteristic adjusting unit that determines the type of the wireless communication medium based on the specific information acquired by the specific information acquisition unit, and that adjusts the communication characteristic with the wireless communication medium to an optimum value based on the determination result;
A wireless communication apparatus comprising: Comprising a resonant circuit including the antenna;
The communication characteristic adjusting unit adjusts the communication characteristic to an optimum value by controlling at least one of a resonance frequency and a quality factor (Q value) of the resonance circuit. 2. The wireless communication device according to 2. In a wireless communication apparatus having an antenna for performing wireless communication using electromagnetic waves with a wireless communication medium, and performing data transmission / reception by performing wireless communication with the wireless communication medium via the antenna,
When a wireless communication medium enters a communicable region, unique information acquisition means for acquiring unique information from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna;
A communication state monitoring unit for monitoring a communication state with the wireless communication medium after acquiring the specific information by the specific information acquisition unit;
When the communication state monitoring unit detects that communication with the wireless communication medium is impossible, the type of the wireless communication medium is determined based on the unique information acquired by the unique information acquisition unit, Antenna output adjusting means for adjusting the output level of the antenna to an optimum value based on the determination result;
A wireless communication apparatus comprising: In a wireless communication apparatus having an antenna for performing wireless communication using electromagnetic waves with a wireless communication medium, and performing data transmission / reception by performing wireless communication with the wireless communication medium via the antenna,
When a wireless communication medium enters a communicable region, unique information acquisition means for acquiring unique information from the wireless communication medium by performing wireless communication with the wireless communication medium via the antenna;
An antenna output adjusting means for determining the type of the wireless communication medium based on the specific information acquired by the specific information acquiring means, and adjusting the output level of the antenna to an optimum value based on the determination result;
A wireless communication apparatus comprising: Comprising transmission / reception means for performing wireless communication using electromagnetic waves with a wireless communication medium via the antenna;
6. The wireless communication apparatus according to claim 4, wherein the antenna output adjustment unit adjusts the output level of the antenna to an optimum value by controlling a power supply voltage of the transmission / reception unit.

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