JP2006073034A - Ic card reader-writer, identification method, program and its recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC card reader-writer, an identification method, a program and its recording medium capable of quickly completing the identification processing of each non-contact IC card. <P>SOLUTION: This invention provides the reader/writer, the identification method, the program and its recording medium, and the reader-writer comprises a storage means for storing the number of normally recognized IC cards, a calculation means for calculating the number of time slots to be included in a first request for identifying each IC card on the basis of the number of the IC cards stored in the storage means, and a slot number resetting means for setting the number of the time slots calculated in the calculation means as the number of slots at the time of the first request. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an IC card reader / writer, an identification method, and a program thereof, and more particularly, to an IC card reader / writer, an identification method, a program, and a recording medium thereof for identifying an IC card using a time slot.

  Conventionally, a time slot system has been adopted for communication between a non-contact IC card that transmits and receives data using an electromagnetic induction system and the like and a reader / writer that identifies the non-contact IC card. This is because when a plurality of non-contact IC cards are simultaneously present in the communicable area of the reader / writer and a plurality of non-contact IC cards respond simultaneously to polling from the reader / writer, each response signal used for the response This is because no contactless IC card can normally communicate with the reader / writer due to the collision.

  The time slot communication method will be described below.

  (1) First, an IC card reader / writer (hereinafter referred to as a reader / writer) transmits an initial response request command as a request to the non-contact IC card in order to confirm the presence of the non-contact IC card. The initial response request command includes a “slot number” or a value necessary for calculating the “slot number” necessary for controlling the timing of the initial response performed by the non-contact IC card.

  (2) After receiving the initial response request command, the non-contact IC card returns the initial response (response) using a time slot provided from a specific time. The time slot used for the response, that is, the timing, is determined by the contactless IC card itself with a random number.

  (3) When the reader / writer detects a collision of responses that occurs when a plurality of contactless IC cards select the same time slot, the reader / writer transmits the initial response request again.

  (4) The reader / writer recognizes all contactless IC cards by receiving responses from all contactless IC cards without collision, and completes the sequence for identifying the cards.

  The above processing will be described in more detail with reference to FIGS. The following is processing of a non-contact IC card when adapted to the international standard ISO / IEC (International Organization for Standardization / International Electrotechnical Commission) 14443 of a proximity type non-contact IC card.

  ISO / IEC14443 can be applied to, for example, a non-contact telephone card. More specifically, as shown in FIG. 16, when three non-contact IC cards 1601, 1602, and 1603 having a function as a telephone card are simultaneously inserted (closed) into a reader / writer 1600 that functions as a public telephone. Is assumed.

  In the ISO / IEC14443 contactless IC card identification system, the contactless IC card is identified by the following procedure.

  First, the reader / writer 1600, which is a public telephone, transmits an initial response request (request). The initial response request has a format shown in FIG. 18, and among the 8 bits in the PARAM 1802 constituting the initial response request 1801, the number of time slots (N) is set to each contactless IC using 3 bits 1803 of bit 1 to bit 3. Notify the card. APf 1804 is a header indicating an initial request command, and AFI 1805 indicates an adaptation class of a non-contact IC card. A CRC (Cyclic Redundancy Check) 1806 is a CRC from APf to PARAM.

  The non-contact IC card responds with N slots from 1 to N. In this explanation, the number of time slots (N) is assumed to be 4. That is, the non-contact IC cards 1601 to 1603 select one of the time slots 1 to 4 and respond to the initial response request.

  In the first card identification processing 1701 shown in FIG. 17, the reader / writer 1600 first transmits an initial response request R1 [REQB] (1702). Assume that the contactless IC cards 1601 and 1602 generate “1” as random numbers and the contactless IC card 1603 generates “2” as random numbers in response to the initial response request R1 (1702). In this case, the non-contact IC cards 1601 and 1602 respond with responses [ATQB] A21 and A31 shown in the time slot 1 (1703), respectively. The non-contact IC card 1603 responds with the response A41 shown in the time slot 2 (1704). In the above case, since the non-contact IC cards 1601 and 1602 respond at the same timing, the reader / writer 1600 detects a non-contact IC card response collision in the time slot 1 (1703). Accordingly, since the non-contact IC cards 1601 and 1602 cannot be identified, the identification process is resumed.

  Subsequently, in the second identification processing 1705, the reader / writer 1600 transmits an initial response request R2 (1706). Here, it is assumed that the non-contact IC card 1601 and the non-contact IC card 1603 generate “1” as a random number and the non-contact IC card 1602 generates “3” as a random number in response to the initial response request. The IC cards 1601 and 1603 respond using the packets A22 and A42 in the time slot 1 (1707), respectively. The non-contact IC card 1602 responds using the packet A32 in the time slot 3 (1708). In this case, the reader / writer 1600 detects a collision of responses of the non-contact IC cards 1601 and 1603 in the time slot 1 (1707). Accordingly, since the reader / writer 1600 cannot identify the non-contact IC cards 1601 and 1603, it restarts the identification process again.

Subsequently, in the third identification processing 1709, the reader / writer 1600 transmits an initial response request R3 (1710). Here, it is assumed that the contactless IC card 1601 generates “1” as a random number, the contactless IC card 1602 generates “3”, and the contactless IC card 1603 generates “4” as a random number in response to the initial response request. . In this case, contactless IC card 1601 is packet A23 in time slot 1 (1711), contactless IC card 1602 is packet A33 in time slot 3 (1712), and contactless IC card 1603 is in time slot 4 (1713). Each packet A43 is responded. Accordingly, since the reader / writer 1600 does not detect a collision, all the non-contact IC cards can be identified, and the identification process is completed. The above is the card identification processing of the non-contact IC card in accordance with ISO / IEC14443.
Here, from when power is turned on to the non-contact IC card (after entering a communicable distance with the reader / writer), each non-contact IC card is positioned as an idle period + ready period until it is identified by the reader / writer. be able to.

  On the other hand, when all the non-contact IC cards are identified, the reader / writer transmits an “ATTRIB” command to each non-contact IC card. This indicates a transition from the idle period + ready period to the active period. When each non-contact IC card receives an “ATTRIB” command or the like and shifts to the active period, various communications with the reader / writer become possible. Each contactless IC card that has shifted to the active period does not respond to the initial response request command. If, for example, a “HALT” command is received instead of the “ATTRIB” command, the non-contact IC card shifts to a halt period and does not communicate with the reader / writer. In this case, when the reader / writer transmits a “WAKE-UP” command, the non-contact IC card shifts to the active period and communication becomes possible.

  In ISO / IEC14443, the time when the contactless IC card responds in time slot 1 after receiving the initial response request command is defined as 302 μsec, and the period (time) of one time slot is 2266 μsec. That is, the timing (μsec) from when the initial response request is received from the reader / writer 1600 until the response is transmitted is given by the following calculation formula (formula 1).

Timing (μsec) = 302 μsec + 2266 μsec × (number of slots (N) −1): (Formula 1)
As a method similar to the time slot method, there is a slot marker method. The slot marker method is a method in which after the reader / writer transmits an initial response request in the time slot method, the reader / writer further transmits a slot marker command indicating the start of the slot at each slot start timing. Therefore, this is essentially the same as the time slot method in that each IC card recognizes each IC card by responding using the time slot designated by the reader / writer.

  Further, Japanese Patent Laid-Open No. 2000-298712 discloses a technique for avoiding a delay in identification processing of a non-contact IC card due to the response collision.

In the technique described in the above Japanese Patent Laid-Open No. 2000-298712, the time slot in which the collision occurred is counted by confirming the collision of the response in each time slot, and the time is determined based on the number of time slots in which the collision occurs. Increase or decrease the number of slots.
JP 2000-298712 A

In a non-contact IC card (such as a non-contact IC card conforming to the international standard ISO / IEC14443) using the time slot method described above, when the non-contact IC card responds to the reader / writer, the non-contact IC card itself Selects a time slot using a random number. For this reason, for example, when the random numbers generated by a plurality of non-contact IC cards are the same, the selected time slots are the same, and the responses always collide. In this case, the reader / writer needs to transmit the response request command again to perform identification processing of the non-contact IC card, and as a result, identification of the non-contact IC card is delayed.

  In the technique described in the above Japanese Patent Laid-Open No. 2000-298712, the non-contact IC card has the same time by increasing the number of time slots designated by the reader / writer based on the number of time slots in which a collision occurs. The probability of selecting a slot is lowered. However, in the above technique, it is necessary to determine whether or not there is a response collision in each time slot and to count and store the number of collisions each time, which complicates the configuration of the reader / writer. Also, the identification process is started by changing (increasing) the number of time slots. If the number of collisions decreases even though the number of non-contact IC cards is not changed, the number of time slots will be decreased next time for identification. Since the process is performed, there is a problem that the frequency of collisions increases again, and the identification processing time becomes long.

  The problem of delaying the identification processing time commonly seen above is particularly noticeable in systems such as train ticket gates where the user needs to identify the contactless IC card to the reader / writer without stopping. appear. That is, the identification of the non-contact IC card is delayed, so that the user needs to stop, resulting in a failure in the use of the system.

  In the future, it can be expected that various systems utilizing the convenience of the non-contact IC card will appear in various fields. In other words, it can be easily predicted that the number of contactless IC cards owned by one user (for example, in a wallet) will increase with time. Under such circumstances, the identification processing time becomes longer, and the problem due to delay becomes more serious. Therefore, it is necessary to prepare for the above situation in advance in terms of extending the useful life of each system.

  On the other hand, if the contactless IC card can be identified at a high speed, it can be applied to a higher-speed moving body. Further speeding up of processing is desired.

  An object of the present invention is to provide an IC card reader / writer, an identification method, a program, and a recording medium for completing the identification processing of each contactless IC card at high speed.

  The present invention employs the following means in order to achieve the above object. That is, the present invention is premised on an IC card reader / writer that communicates with a plurality of IC cards using one or more time slots. Here, the storage means stores the number of IC cards when the plurality of IC cards are normally recognized, and the calculation means stores each IC card based on the number of IC cards stored in the storage means. The number of time slots (initial value) included in the first request for identification is calculated, and the slot number resetting means sets the number of time slots calculated by the calculating means as the slot number at the time of the first request.

  Accordingly, the number of time slots can be dynamically changed based on the past history of recognizing the IC card, and the identification processing time of each card can be shortened with a high probability. At the same time, it is possible to extend the useful life of the system using the reader / writer.

  The reader / writer can be embodied using a computer.

  In the reader / writer according to the present invention, it is possible to shorten the identification processing time of each card with high probability by dynamically changing the number of time slots based on the past history of recognizing the non-contact IC card. become. At the same time, it is possible to extend the useful life of the system using the reader / writer.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: It is not the thing of the character which limits the technical scope of this invention.

(Embodiment 1)
First, the reader / writer according to the first embodiment of the present invention will be described. FIG. 1 is a functional block diagram of the reader / writer 101 according to the first embodiment. FIG. 2 is a hardware configuration diagram of the reader / writer 101.
The reader / writer 101 includes an antenna 203, a transmission / reception circuit 202, a CPU 201, a ROM (Read Only Memory) 104 storing a program for controlling the reader / writer, and a RAM (Random) used as a work area when the program is executed. Access Memory) 205.

  Note that a non-contact IC card that communicates with the reader / writer 101 operates with power induced by electromagnetic waves from the reader / writer when entering the communicable area of the reader / writer 101.

  When the reader / writer 101 is represented by function, the reader / writer 101 includes antenna means 107, transmission / reception means 106, control means 105, response detection means 102, and response invalidation means 103 as shown in FIG. However, details of the processing of each means will be described as appropriate.

  For example, the response detection unit 102 and the response invalidation unit 103 are stored as programs in the ROM 104 and read out and executed by the CPU 201 as necessary.

  Next, the processing of the reader / writer according to the first embodiment will be described with reference to FIG. 1, FIG. 3, FIG. 4, and FIG. FIG. 3 is a flowchart of processing executed by the reader / writer 101. For the sake of understanding, it is assumed in the first embodiment that three non-contact IC cards 410, 420, and 430 communicate with the reader / writer 101 as shown in FIG.

  First, the control means 105 constituting the reader / writer 101 transmits an initial response request 450 to the non-contact IC card at a predetermined time interval (FIG. 3: S301). The initial response request is transmitted at intervals of several tens of milliseconds, for example. Here, when the non-contact IC cards 410, 420, and 430 receive the initial response request transmitted by the reader / writer 101, each non-contact IC card acquires the number of time slots included in the initial response request. Note that the number of time slots is specified by 3 bits 1803 of Bit 1 to Bit 3 of PARAM shown in FIG. 18, and a multiplier of 2 of the value specified in these bits is the number of time slots.

  Next, each of the contactless cards 410 to 430 determines a time slot to be used for a response by selecting one of the number of time slots given from the reader / writer 101.

  Subsequently, the non-contact IC card waits until a time slot (timing) for transmitting a response to the reader / writer, and transmits a response to the initial response request at the selected time slot (timing).

  The response transmitted from the non-contact IC card is received by the control means 105 via the antenna means 107 and the transmission / reception means 106 constituting the reader / writer 101. Here, the non-contact IC card 410 selects time slot 2 (451), the non-contact IC card 420 selects time slot 3 (452), and the non-contact IC card 430 selects time slot 2 (451). Assuming that

  Under the above assumption, the control means 105 transmits a response to the response detection means 102 because no response is received in time slot 1 (457). Next, the control means 105 receives the responses 453 and 455 of the contactless IC cards 410 and 430 transmitted in the time slot 2 (451), and transmits the received responses to the response detection means 102. . Further, the control means 105 receives the response 454 of the non-contact IC card 420 transmitted in the time slot 3 (452), and transmits the received response to the response detection means 102. Further, since the control means 105 does not receive a response in time slot 4 (458), it sends a message to that effect to the response detection means 102 (FIG. 3: S301).

  The response detection means 102 having received the response corresponding to each time slot, as described above, once stores the response corresponding to each time slot in the predetermined storage means corresponding to each time slot, Detect (determine) whether the response is “normal response” or “collision”.

  Note that the response determination process described in step S301 in FIG. 3 is performed from the transmission of the initial response request described above to the determination of “collision”.

  Here, responses corresponding to the time slot 1 (457) and the time slot 4 (458) are not detected, but in the time slot 2 (451), the contactless IC card 410, the contactless IC card 430, Is detected as a “collision”. In the time slot 3 (452), only the response by the non-contact IC card 420 is detected, so that “normal response” is detected.

  Subsequently, when a “collision” is detected by the response detection means 102, the response invalidation means 103 constituting the reader / writer 101 is set to, for example, “1” in a counter provided in the response invalidation means 103. Is set (FIG. 3: S302 YES → S303).

  If no "collision" is detected by the response detection means 102, there is no non-contact IC card capable of communication within the communication range of the reader / writer 101, or a response from each non-contact IC card has been received without any problem. The processing of the response detection unit 102 ends (FIG. 3: S302 NO → end). If a response is received, the control unit 105 performs subsequent communication processing.

  When the response invalidating means 103 sets “1” in the counter, the predetermined storage means corresponding to the time slot N (N is the counter value) indicated by the counter is referred to, and the “normal response” "Is stored.

  Here, since no response is recorded in the storage means corresponding to the time slot 1 (457), it is confirmed whether the number of time slots transmitted in the initial response request and the counter value match. (FIG. 3: S304 NO → S306).

  Next, when the number of the transmitted time slots and the value of the counter do not match, the counter is incremented by 1, and the storage means corresponding to the time slot 2 (451) indicated by the next counter again reads “normal”. It is determined whether “response” is stored (FIG. 3: S304 → S306 NO → S307 → S304).

  When the above processing is repeated, a normal response is stored in the storage means corresponding to time slot 3 (452) under the above assumption. In this case, the response invalidation means 103 performs response invalidation processing (FIG. 3: S304 YES (N = 3) → S305).

  The response invalidation process is performed as follows. That is, the response invalidation means 103 reads the content of the response from the storage means corresponding to the time slot 3 (452), thereby acquiring information unique to the non-contact IC card 420. Subsequently, the response invalidation means 103 transmits a response invalidation command 446 including the unique information to the non-contact IC card 420 via the control means 105, the transmission / reception means 106, and the antenna means 107.

  Here, the response invalidation command is a command indicating that it does not respond to an initial response request (command) transmitted from the reader / writer 101 until a command indicating the end of communication with the reader / writer 101 is received thereafter. It is. Specifically, for example, an “ATTRIB” command or “HALT” command defined in ISO / IEC14443 corresponds to this, but a command newly defined in the design of the reader / writer and the non-contact IC card may be used.

  The contactless IC card 420 that has received the response invalidation command does not respond to the initial response request until a command indicating the end of communication with the reader / writer 101 is received, but communication other than the initial response request. I.e., shift to the active period. However, when the “HALT” command is received, the halt period starts and normal communication is not performed until the “WAKE-UP” command is received.

Now, in step (S306) of FIG. 3, all the responses have been determined because the number of time slots transmitted by the control means 105 matches the counter, and the response determination processing is repeated again (FIG. 3: S306 YES) → S301)
Subsequently, the reader / writer 101 that invalidates the non-contact IC card 420 performs the second identification process 442. The second identification process 442 performs almost the same process as the first identification process 441, but the non-contact IC card 420 has already been invalidated, so the second identification process 442 performs the non-contact IC card 410. And the non-contact IC card 430 may be identified.

  That is, the reader / writer 101 transmits an initial response request 460. The initial response request is received by the non-contact IC cards 410 to 430, but the non-contact IC card 420 is invalidated and thus does not respond.

  Here, it is assumed that the contactless IC card 410 selects time slot 2 (461) and the contactless IC card 430 selects time slot 1 (462) in response to the initial response request.

  Under the above assumption, the control unit 105 receives the response 463 of the non-contact IC card 430 transmitted in the time slot 1 (462), and transmits the received response to the response detection unit 102. The control unit 105 receives the response 464 of the non-contact IC card 410 transmitted in the time slot 2 (461) and transmits the received response to the response detection unit 102. Since the control means 105 does not receive a response in the time slot 3 (465) and the time slot 4 (466), the control means 105 transmits that fact to the response detection means 102.

  That is, under the above assumption, the response detection unit 102 does not detect “collision”, so that the reader / writer 101 can identify the non-contact IC cards 410 and 430 as in the conventional case. Thereafter, the non-contact IC cards 410, 420, and 430 identified by the reader / writer 101 can communicate with the reader / writer 101.

  As described above, when a normal response is received, a response invalidation command is transmitted to the IC card that has transmitted the normal response even if the collision is detected. Only the IC card that sent the response that caused the collision is targeted. In other words, in the subsequent identification process, the probability of collision of responses decreases, that is, the identification process can be completed at high speed.

  Note that the present invention may be applied to a reader / writer using a contact IC card instead of the non-contact IC card. Further, the present invention may be applied to a reader / writer using a slot marker method instead of the time slot method, or may be applied to a reader / writer using another slot method.

  The invalidation command may simultaneously invalidate a plurality of non-contact IC cards that have made a normal response with one invalidation command by including a plurality of pieces of information unique to the non-contact IC card.

(Embodiment 2)
Next, the reader / writer 601 according to Embodiment 2 of the present invention will be described with reference to FIGS. 6, 7, and 8. FIG.

  The reader / writer 601 in FIG. 6 has the same configuration as the reader / writer 101 in the first embodiment, but instead of the response detection unit 102 and the response invalidation unit 103, a collision detection unit 602 and a slot number increase unit 603 are used. Is provided. Details of each means will be described later. FIG. 7 is a flowchart of processing executed by the reader / writer 601 according to the second embodiment.

  First, for the sake of understanding, the situation shown in FIG. 5 is taken as an example. That is, here, the reader / writer 601 performs identification processing for identifying three different non-contact IC cards 410, 420, and 430.

  First, the control means 105 constituting the reader / writer 601 transmits an initial response request, and sets “1” as the number of time slots in the initial response request (FIG. 7: S701).

  This is because, for example, a reader / writer that communicates with a plurality of non-contact IC cards does not know the number of non-contact IC cards in the first non-contact IC card identification process, so there is only one non-contact IC card that can communicate. It is assumed that “1” is set. In this way, when communicating with a plurality of non-contact IC cards, there is always a response collision in the first identification process, but since there is only one time slot, the first initial response Processing related to the request is completed in a short time. For this reason, a reader / writer that often communicates with only one contactless IC card can complete the identification process in a short time by setting the number of time slots to “1” in the first identification process. Become.

  The control means 105 sets the number of time slots to “1”, and then performs non-contact IC card identification processing (FIG. 7: S702). That is, as shown in FIG. 8, the reader / writer 601 transmits an initial response request 803 in the first identification processing 801. Since the number of time slots set in the initial response request is “1”, the contactless IC cards 410, 420, and 430 can select only the time slot 1 (802) as a response. That is, the response 804 of the non-contact IC card 410, the response 805 of the non-contact IC card 420, and the response 806 of the non-contact IC card 430 are transmitted to the time slot 1 (802).

  The responses 804 to 806 are received by the control means 105 via the antenna means 107 and the transmission / reception means 106 constituting the reader / writer 601. Next, the control unit 105 transmits responses 804 to 806 corresponding to the time slot 1 to the collision detection unit 602. The collision unit 602 determines whether or not “collision” is included in the response corresponding to the time slot 1 from the content of the response corresponding to the time slot 1.

  Here, the response corresponding to the time slot 1 is detected as “collision” because the responses 804 to 806 are included (FIG. 7: S703 YES).

  When the collision detection unit 602 detects a “collision”, the fact is notified to the slot number increasing unit 603, and the slot number increasing unit 603 increases the time slot number for the next initial response request. The number is set to a value larger than “1”, that is, the number of time slots is increased (FIG. 7: S704). Here, it is assumed that “4” is set as the number of time slots.

  When the slot number increasing means 603 sets “4” to the number of time slots, the control means 105 transmits the initial response request 811 again in the second identification process 807 (FIG. 7: S702).

  Here, for example, the contactless IC card 410 transmits time slot 2 (809) for transmission of the response 812, the contactless IC card 420 transmits time slot 4 (810) for transmission of the response 813, and the contactless IC card 430. Suppose that time slot 1 (808) is selected for transmission of response 814.

  The responses 812 to 814 are received by the control unit 105 in the order corresponding to the time slots 1 to 4, that is, the order of the response 814, the response 812, and the response 813, and then transmitted to the collision detection unit 602.

  Here, since no collision is detected in the collision detection means 602, the time slot is not increased (FIG. 7: S703 NO → END). Naturally, since each of the responses 812 to 814 is identified as a normal response by the reader / writer, the non-contact IC cards 410 to 430 and the reader / writer 601 can communicate thereafter.

  As described above, only the presence or absence of a response collision from the IC card is detected, and the time slot is increased based only on the presence or absence of the collision, so that the number of IC cards can be increased without adding a complicated configuration to the reader / writer. Accordingly, identification can be performed efficiently.

  Note that the present invention may be applied to a reader / writer using a contact IC card instead of the non-contact IC card. Further, the present invention may be applied to a reader / writer using a slot marker method instead of the time slot method, or may be applied to a reader / writer using another slot method.

  The increase in the number of time slots may be a fixed value or a variable value.

  Furthermore, in a reader / writer that is expected to communicate with a plurality of IC cards from the beginning, it is not always necessary to set “1” to the number of time slots of the first initial response request, and the number of time slots corresponding to the reader / writer is set. It may be set.

(Embodiment 3)
Next, a reader / writer 901 according to Embodiment 3 of the present invention will be described with reference to FIG. 9, FIG. 10, FIG. 11, and FIG.

  FIG. 9 has the same configuration as the reader / writer 101 in the first embodiment and the reader / writer 601 in the second embodiment, and the response detecting means 102 has the function of the collision detecting unit 602 in the second embodiment. ing. That is, the reader / writer 901 includes a response detection unit 102, a response invalidation unit 103, and a slot number increase unit 603. FIG. 10 is a flowchart of processing executed by the reader / writer 901 according to the third embodiment. In each process, the same processes as those in the first and second embodiments are denoted by the same numbers.

  In the third embodiment, it is assumed that a non-contact IC card 440 is further added in addition to the situation shown in FIG. First, when the reader / writer 901 communicates with the non-contact IC cards 410, 420, 430, and 440, the control means 105 sets “1” to the number of time slots of the initial response request 1103 used for the first identification processing 1101. Setting is performed (FIG. 10: S701).

  Subsequently, when the control means 105 transmits an initial response request 1103, each non-contact IC card 410-440 responds to the initial response request (FIG. 10: S702). Here, since the number of time slots is set to “1”, the responses 1104 to 1107 of the non-contact IC cards 410 to 440 are transmitted at the timing of the time slot 1 (1102). For this reason, the response detection means 102 constituting the reader / writer 901 detects that the response corresponding to the time slot 1 (1102) stored in the predetermined storage means is “collision” (FIG. 10: S302 YES).

  If no "collision" is detected by the response detection means 102, there is no non-contact IC card capable of communication within the communication range of the reader / writer 901, or a response from each non-contact IC card has been received without any problem. And the processing of the response detection unit 102 ends (FIG. 10: S302 NO → end). If a response is received, the control unit 105 performs subsequent communication processing.

  Subsequently, when the response detection unit 102 detects “collision”, the response invalidation unit 103 included in the reader / writer 901 sets, for example, “1” in a counter provided in the response invalidation unit 103. (FIG. 10: S302 YES → S303).

  Next, when the response invalidation means 103 sets “1” in the counter, the predetermined storage means corresponding to the time slot N (N is the counter value) indicated by the counter is referred to, and “normal” It is determined whether “response” is stored.

  Here, since a normal response is not recorded in the storage means corresponding to the time slot 1 (1102), the number of time slots subsequently transmitted in the initial response request matches the value of the counter. Is confirmed (FIG. 10: S304 NO → S306).

  Here, since the number of time slots is “1”, the slot number increasing means 603 increases the value of the number of time slots set in the initial response request 1102 transmitted in the second identification processing 1108 (FIG. 10: S306YES-> S704). Here, it is assumed that “4” is set as the number of time slots.

  Subsequently, when the initial response request 1112 is transmitted, each contactless IC card 410 to 440 selects one from the set four time slots. Here, for example, contactless IC cards 410 and 430 select time slot 2 (1110), contactless IC card 420 selects time slot 1 (1109), and contactless IC card 440 selects time slot 3 ( 1111) is selected.

  In this case, the response detection means 102 makes contact with the response 1114 of the non-contact IC card 420 in response to the time slot 1 (1109), and makes contact with the response 1113 of the non-contact IC card 410 in response to the time slot 2 (1110). The “collision” with the response 1115 of the IC card 430 is detected, and the response 1116 of the non-contact IC card 440 is detected based on the response of the time slot 3 (1111).

  Since the response detection unit 102 detects the “collision”, the response invalidation unit 103 repeats the processes S303 to S366 in FIG. A response invalidation command 1118 is transmitted to the non-contact IC card 440.

  Thereby, the non-contact IC card 420 and the non-contact IC card 440 shift to the active period, that is, do not perform a response to the subsequent initial response request.

  Subsequently, the counter N is compared with the number of time slots, and when processing for all four time slots is completed, the slot number increasing means 603 performs time slot number increasing processing in the third identification processing 1201 (FIG. 10). : S306 YES → S704).

  Here, the slot number increasing means 603 may increase the number of time slots, but here, the slot number increasing means 603 receives that the response invalidation processing has been performed from the invalidating means 103. Thus, the slot number increasing means 603 does not increase the number of time slots.

  As described above, by determining the increase in the number of time slots based on whether or not the response invalidation process is executed, there is no need to increase the number of unnecessary time slots, that is, the delay of the identification process due to the increase in the number of time slots. Can be prevented.

  Subsequently, the control means 105 transmits an initial response request 1205 for the third identification process 1201 (FIG. 10: S301). Note that the number of time slots in the initial response request 1205 is “4”.

  In the third identification processing 1201, the contactless IC card 410 selects time slot 2 (1203), and the contactless IC card 430 selects time slot 4 (1204). Since the non-contact IC cards 420 and 440 have already shifted to the active period due to the response invalidation processing, as described above, the non-contact IC cards 420 and 440 do not respond to the initial response request.

  In the third identification processing 1201, the response detection means 102 does not detect “collision” and detects “normal response”, so the non-contact IC cards 410 and 430 are normal (conventional). By the above process, the reader / writer 901 discriminates (FIG. 10: S302 → end).

  Thereafter, the non-contact IC cards 410 to 440 perform predetermined communication with the reader / writer 901, and the communication is terminated by, for example, a “HALT” command.

  In the subsequent (next) identification processing 1208, since the identification processing is repeated again from step S701, the number of time slots set in the initial response request 1210 is “1”.

  In addition, the non-contact IC cards 420 and 440 whose response has been invalidated can also respond to the initial response request (the active period ends) by the “HALT” command at the end of communication or the like.

  As described above, an IC card corresponding to a response that has not caused a collision performs a response invalidation process each time, thereby performing identification processing only for the IC card that has caused the collision, and appropriately setting the number of time slots. By increasing the number, even in a system that requires identification of a large number of IC cards, identification according to the number of IC cards can be performed flexibly and efficiently.

  As in the first and second embodiments, the present invention may be applied to a reader / writer using a contact IC card instead of the non-contact IC card. Further, the present invention may be applied to a reader / writer using a slot marker method instead of the time slot method, or may be applied to a reader / writer using another slot method.

  The increase in the number of time slots may be a fixed value or a variable value.

  Furthermore, in a reader / writer that is expected to communicate with a plurality of IC cards from the beginning, it is not always necessary to set “1” as the number of time slots in the first initial response request. It may be set.

(Embodiment 4)
Next, a reader / writer 1301 according to Embodiment 4 of the present invention will be described with reference to FIGS.

  The reader / writer 1301 in FIG. 13 has the same configuration as the reader / writer 101 in the first embodiment, but instead of the response detection unit 102 and the response invalidation unit 103, a storage unit 1302, a calculation unit 1303, and a slot number re-save. Setting means 1303 is provided. Details of each means will be described later. FIG. 14 is an image diagram of data stored in the storage unit 1302, and FIG. 15 is a flowchart of processing executed by the reader / writer 1301 according to the fourth embodiment.

As described in the first to third embodiments, the control unit 105 recognizes the plurality of non-contact IC cards by transmitting an initial response request to the plurality of non-contact IC cards, for example. Is the same.
Here, when the recognition is completed normally, the storage means 1302 stores the number of non-contact IC cards recognized normally. For example, as a storage method, as shown in FIG. 14A, ten storage areas are provided here, and the recognized number is sequentially stored in the storage areas 1401 to 1410 from the newest one. In this way, it is possible to store 10 recently recognized contactless IC cards.

  Next, when the storage in the storage unit 1302 is completed, the calculation unit 1303 determines the number of time slots to be included in the initial response request to be transmitted next time based on the stored number of the ten contactless IC cards. It is calculated. Here, any method of calculating the number of slots may be used. For example, the average value of the number of the past 10 times may be used. In this case, for example, the fraction may be rounded up or rounded down. Specifically, in the example illustrated in FIG. 14A, the average of the numerical values (numbers) stored in the storage areas 1401 to 1410 is “1.2”, and the number of time slots included in the initial response request is “1”. (Turn down). In contrast, for example, FIG. 14B shows an example in which non-contact IC cards are widespread and non-contact IC cards in a wallet or the like increase. In this case, the number of sheets recognized at a time is increasing, and the average of the numerical values (numbers) stored in the storage areas 1411 to 1420 shown in FIG. 14B is “5.1”, which is the time included in the initial response request. The number of slots is “5” (adopting truncation).

  The number of time slots calculated by the calculation unit 1303 is notified to the slot number resetting unit 1304, and the slot number resetting unit 1304 notifies the numerical value notified to the number of time slots included in the subsequent initial response request. Is set.

  Thereafter, the control means 105 transmits an initial response request using the numerical value reset by the slot number resetting means 1304 (“5” in the case of FIG. 14B). When recalculating the number of time slots using the numerical value included in the initial response request on the non-contact IC card side, the numerical value calculated on the non-contact IC card side is “5” or more. In addition, “3” is stored in the initial response request.

  As described above, it is possible to shorten the identification processing time of each card with a high probability by dynamically changing the number of time slots based on the past history of recognizing the non-contact IC card. Further, even when the number of non-contact IC cards owned by one user increases (changes) over time, the system using the reader / writer automatically changes the initial value of the time slot. As a result, the useful life of the system can be extended.

  Next, a calculation method in which the number of time slots by the calculation unit 1303 is different will be described with reference to FIG.

  In the method described below, the calculation unit 1303 changes the initial value by paying attention to the continuity of the recognized number of sheets.

  First, it is assumed that the control means 105 completes the identification process with the initial value (number of time slots) included in the initial response request as N (FIG. 15: S1501). Then, the storage means 1302 stores the recognized number n1 in the storage area 1421 and copies the number recognized in the previous process stored in the storage area 1421 to the storage area 1422 to obtain the number n2. To do.

  Next, the calculation means 1303 obtains the numbers n1 and n2 from the storage means 1302 and compares whether or not the two numbers are the same (FIG. 15: S1502 → S1503).

  If n1 and n2 are not the same, the continuous counter nc is set to “0” (FIG. 15: S1503 NO → S1504). Here, the continuous counter nc is a value indicating how many times the same number of cards are recognized.

  The calculation means 1303 adds “1” to the card search count Ns, and further adds the n1 to the history count Nsum (FIG. 15: S1505 → S1506). Here, the card search number Ns indicates the number of times the reader / writer has successfully completed the identification processing of the non-contact IC card so far, and the history number Nsum indicates the non-contact IC recognized by the reader / writer so far. Indicates the number of cards.

  Subsequently, the calculation unit 1303 substitutes a numerical value calculated by “Nsum ÷ Ns × 1.5” (rounded up after the decimal point) for the initial value N (FIG. 15: S1507). Here, “Nsum ÷ Ns” indicates an average value of the number of cards recognized in the identification processing per time until now. Note that an initial value larger than the number of cards is calculated by multiplying “Nsum ÷ Ns” by “1.5”, but “1.5” may be another value.

  The initial value N calculated by the calculation means 1303 is notified to the slot number resetting means 1304, and the slot number resetting means 1304 sets the notified value as the initial value N. The initial value N is used in a subsequent initial response request (identification process) by the control means 105.

  In the comparison process: when n1 and n2 are the same in S1503, the continuous counter nc is incremented by “1” and the threshold Nx is compared with the continuous counter Nc (FIG. 15: S1503 YES → S1508 → S1509).

  If the continuous counter nc <= Nx, the initial value N is determined in steps S1505 to S1507 (FIG. 15: S1509 NO → S1505... S1507) as described above.

  On the other hand, when the continuous counter nc> Nx, the card search count Ns is initialized to “0”, and the history count Nsum is also initialized to “0” (FIG. 15: S1509 YES → S1510 → S1511). Subsequently, the calculation unit 1303 determines whether n1 is “1” (FIG. 15: S1512).

  Here, when n1 is “1”, the initial value N is set to “1”, and the initial value N is used in the subsequent initial response request (identification process) by the control means 105 (FIG. 15: S1512 YES). → S1513).

  If n1 is not “1”, a numerical value calculated by “n1 × 1.5” (rounded up after the decimal point) is substituted for the initial value N, and the initial value N is calculated by the control means 105 thereafter. In the initial response request (identification process) (FIG. 15: S1512 NO → S1514). Here, the numerical value “1.5” is a value for calculating an initial value larger than the number of cards, as described above, but “1.5” may be another numerical value.

  As described above, the threshold value (Nx) may be used to determine the continuous number of recognized cards, and the initial value may be calculated based on the continuous number. In the above process, when the recognized number is “1”, the process of rounding up by “1.5” is not performed. This is because when the number of cards is one, the identification process can be completed most quickly by setting the initial value to “1”.

  The storage means, calculation means, and slot number resetting means in the fourth embodiment can be implemented in addition to the first to third embodiments. By carrying out simultaneously, it becomes possible to further shorten the identification processing time.

  As described above, when a normal response is received, a response invalidation command is transmitted to the IC card that has transmitted the normal response even if the collision is detected. Only the IC card that sent the response that caused the collision is targeted. In other words, in the subsequent identification process, the probability of collision of responses decreases, that is, the identification process can be completed at high speed.

  In addition, only the presence / absence of a response collision from the IC card is detected, and the time slot is increased based only on the presence / absence of the collision. Therefore, the reader / writer is identified according to the number of IC cards without adding a complicated configuration. Can be performed efficiently.

  Furthermore, the IC card corresponding to the response that does not cause a collision is subjected to a response invalidation process each time, so that only the IC card that has caused the collision is subjected to an identification process, and the number of time slots is appropriately increased. Therefore, even in a system that requires identification of a large number of IC cards, identification can be performed flexibly and efficiently according to the number of IC cards.

  Further, by dynamically changing the number of time slots based on the past recognition history of the non-contact IC card, it becomes possible to shorten the identification processing time of each card with a high probability. At the same time, it is possible to extend the useful life of the system using the reader / writer.

2 is a functional block diagram of a reader / writer in Embodiment 1. FIG. 2 is a hardware configuration diagram of a reader / writer according to Embodiment 1. FIG. 5 is a flowchart of processing executed by the reader / writer according to the first embodiment. 3 is an image diagram of identification processing in Embodiment 1. FIG. The communication image figure of a reader / writer and a non-contact IC card. FIG. 6 is a functional block diagram of a reader / writer in Embodiment 2. 10 is a flowchart of processing executed by the reader / writer according to the second embodiment. FIG. 10 is an image diagram of identification processing in the second embodiment. FIG. 11 is a functional block diagram of a reader / writer according to Embodiment 3. 10 is a flowchart of processing executed by the reader / writer according to the third embodiment. FIG. 10 is a first image diagram of identification processing in the third embodiment. FIG. 10 is a second image diagram of identification processing in the third embodiment. FIG. 10 is a functional block diagram of a reader / writer in Embodiment 4; The image figure of the data which a memory | storage means memorize | stores. 10 is a flowchart of processing executed by the reader / writer according to the fourth embodiment. The communication image figure of the conventional reader / writer and a non-contact IC card. The image figure of the conventional identification process. The figure which shows the format of an initial response request packet.

Explanation of symbols

101 Reader / Writer 102 Response Detection Unit 103 Response Invalidation Unit 104 ROM
105 Control means 106 Transmission / reception means 107 Antenna means

Claims (5)

In an IC card reader / writer that communicates with a plurality of IC cards using one or more time slots,
Storage means for storing the number of normally recognized IC cards;
Calculation means for calculating the number of time slots to be included in the initial request for identifying each IC card based on the number of IC cards stored in the storage means;
A reader / writer comprising: a slot number resetting means for setting the number of time slots calculated by the calculating means as the slot number at the time of the first request.   The reader / writer according to claim 1, wherein the storage unit stores the number of IC cards for a predetermined number of times. In an identification method for identifying a plurality of IC cards in a communicable manner,
A storage step of storing the number of the IC cards when each of the plurality of IC cards is normally recognized;
A calculation step for calculating the number of time slots to be included in the initial request for identifying each IC card based on the number of IC cards stored in the storage step;
An identification method, comprising: a slot number resetting step for setting the number of time slots calculated in the calculation step as a slot number at the time of the first request. To a computer that identifies a plurality of IC cards in a communicable manner,
A storage step of storing the number of the IC cards when each of the plurality of IC cards is normally recognized;
A calculation step for calculating the number of time slots to be included in the initial request for identifying each IC card based on the number of IC cards stored in the storage step;
A program for executing a slot number resetting step for setting the number of time slots calculated in the calculation step as the slot number at the time of the first request. To a computer that identifies a plurality of IC cards in a communicable manner,
A storage step of storing the number of the IC cards when each of the plurality of IC cards is normally recognized;
A calculation step for calculating the number of time slots to be included in the initial request for identifying each IC card based on the number of IC cards stored in the storage step;
A computer-readable recording medium recording a program for executing a slot number resetting step for setting the number of time slots calculated in the calculating step as the slot number at the time of the first request.

Images