JP4805494B2 - Interference prevention method for reader / writer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an interference prevention method for a reader / writer, and more particularly to an interference prevention method between a reader / writer for a non-contact type IC card and a reader / writer of a different type.
[0002]
[Prior art]
In recent years, new information recording media called IC cards are widely available on the market. The IC card is a generic name for cards having a card-like or sheet-like shape such as a credit card, a bank card, a point card, etc., and an IC (Integrated Circuit) incorporated in the card. Among them, a non-contact type IC card is being considered to be used instead of the current magnetic card system as a commuter pass used when getting on and off a railway. In addition, in light of resource conservation and environmental issues, government agencies are strongly promoting IT (Information Technology) as a means of promoting paperlessness and as part of realizing labor savings, especially in the areas of welfare and public facilities. The use of IC cards is emerging as a card that can be used efficiently for a wide range of administrative services in national and local governments, such as use and issuance of various certificates.
In particular, the above-mentioned contactless IC card exchanges data by radio wave, so there is no need to take out a commuter pass each time when passing through the ticket gate, and information can be exchanged even from inside a regular slot or bag. It is expected that the performance will be greatly improved, and is attracting attention as an alternative to conventional recording media. However, as a transitional stage, a conventional card reader / writer called a one-time ticket is used in close proximity to the non-contact IC card reader / writer.
[0003]
FIG. 7 is an operation flowchart when a conventional card reader / writer called the one-time ticket is used in close proximity to the non-contact IC card reader / writer. For example, here, a reader / writer for a non-contact IC card is a reader / writer A, and a reader / writer for a one-time ticket card is a reader / writer B. First, the host device (not shown) and the reader / writers A and B perform an authentication operation (step S60). Next, the reader / writer A emits radio waves (step S61). Subsequently, the reader / writer B emits radio waves (step S62). Next, it is checked whether the reader / writer A has a response (step S63). If YES, the card A is communicated (step S64), and the communication completion is determined (step S65). If NO, the process returns to step S63, and if YES, the process returns to step S61. If NO in step S63, it is checked whether there is a response in reader / writer B (step S66). If YES, communication of card B is performed (step S67), and communication completion is determined (step S68). If NO, the process returns to step S66, and if YES, the process returns to step S62. If NO in step S66, the process returns to step S61.
[0004]
[Problems to be solved by the invention]
As described above, the non-contact IC card exchanges data with radio waves, so it is highly convenient but highly reliable. That is, misrecognition of data due to external noise and deterioration of operability due to different types of IC cards must be suppressed as much as possible. However, in the case of a ticket checker in which a card reader of a one-time ticket and a non-contact type IC card are installed close to each other as shown in FIG. 7, radio waves are always emitted from both reader / writers. Malfunction due to interference or other noise becomes a problem.
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly reliable and inexpensive reader / writer by a method that does not interfere with each other even when reader / writers of different systems are installed close to each other.
[0007]
[Means for Solving the Problems]
To solve the present invention such problems, a first aspect of the invention, via the loop antenna of the IC card, a plurality of non-performing in a non-contact transmission and reception of transmission data of the transport power based on a predetermined modem scheme In a contact IC card reader / writer and a method for preventing interference between reader / writers of a different type from the reader / writer, after completion of an authentication operation with a host device of each reader / writer, any one of the plurality of reader / writers When the reader / writer emits radio waves and there is no response from the non-contact IC card to the reader / writer, or when communication with the non-contact IC card is completed, a series of operations to stop the radio waves of the reader / writer are performed, and The reader / writer other than the reader / writer that has completed the series of operations is controlled to repeat the series of operations, and all the reader / writers complete the series of operations. It repeats until it ends .
When one of the reader / writers emits radio waves alternately, confirms whether or not there is a response each time and selects one of them, the other reader that is not selected until the communication of the selected reader / writer is completed or terminated. Stop the writer. According to this invention, since radio waves are alternately emitted from both reader / writers, it is possible to avoid the influence of noise and to realize highly reliable communication.
The invention of claim 2 is also an effective means of the present invention that the emission time of the radio waves alternately emitted from the two reader / writers is a time necessary and sufficient for establishing communication. The longer the radio wave emission duration, the higher the probability of capturing it. However, if it is too long, the access time is affected and the convenience of the user is deteriorated. Therefore, it is preferable that the time satisfying both is determined. According to such technical means, since the emission time of the alternately emitted radio waves is a time necessary and sufficient for establishing communication, communication can be performed without impairing access time and convenience.
The invention of claim 3 is also an effective means of the present invention that the reader / writer of the different system is a reader / writer that recognizes that the reader / writer has been selected by inserting a card.
A reader / writer installed in the vicinity of a reader / writer for a non-contact IC card is a reader / writer in which a sensor works when a card is inserted and the subsequent operation proceeds. Therefore, even if the main power supply is stopped or the radio wave is stopped until the card is inserted, the operation is not affected. According to this technical means, since it is recognized that the reader / writer has been selected by inserting the card, it is possible to stand by with the radio wave and the main power supply stopped.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a block diagram showing a configuration of an IC card reader / writer according to an embodiment of the present invention. The configuration of this IC card reader / writer 100 is an external computer 50 that controls the entire system by sending / receiving data to / from the reader / writer 100, and a transmission / reception device 1 that controls the data communication protocol between the external computer 50. A control device 2 that controls the operation of the reader / writer 100 as a whole, firmware that records a procedure for operating the control device 2, a memory device 3 that stores a plurality of double modulation schemes, and data from the control device 2 as a carrier wave Modulator 4 that carries and modulates, input device 5 that inputs an operation command, display device 6 that displays information from control device 2, power supply signal that is an AC signal from control device 2, and modulator 4 A power amplifier 7 for amplifying the write command from the signal, and detection for converting the carrier wave received from the loop antenna 9 into binary data A modulator 8, the loop antenna 9 to the transfer of power carriers and data with the IC card (not shown), has a random number table, and a random number generator 10 for generating a random number from the random number table.
Next, before describing the operation of the reader / writer 100 according to this configuration, the configuration of the paired IC cards will be described first. FIG. 2 is a block diagram showing the configuration of the non-contact type IC card according to the embodiment of the present invention. The configuration of the contactless IC card 200 according to the embodiment includes a loop antenna 20 that transmits and receives data using a power carrier wave from the reader / writer 100, a transmission / reception circuit 21 that generates a write command read command, and a loop antenna 20. A power generation circuit 22 that receives a power carrier wave, rectifies it and converts it to DC power, a memory device 23 that manages temporary storage of control firmware and data, and a carrier wave on a transmission command from the control circuit 26 to modulate And a modulator 25 for converting the carrier wave data from the transmission / reception circuit 21 into binarized data, and a control circuit 26 for controlling the entire operation of the IC card 200.
[0009]
Next, each operation will be described with reference to FIGS. 1 and 2 together. When a power supply (not shown) is turned on, the reader / writer 100 starts an operation according to a program stored in the memory device 3 after the initial operation of the control device 2. First, initialization with the host device 50 is performed by the sequence shown in FIG. 3A (details will be described later). Next, the control device 2 alternately transmits a power supply signal supplied to the IC card 200 and a polling signal from the power amplifier 7. The signal is radiated to the outside from the loop antenna 9 as an electromagnetic wave. For example, in ISO 14443 type B, the center carrier frequency is 13.56 MHz ± 7 KHz, the AM modulation degree is 10%, the modulation method ASK (Amplitude Shift Keying), the encoding method is NRZ-L, and the communication speed is 106 kb / s. Next, when the IC card 200 comes close to the reader / writer 100, the loop antenna 20 receives the power supply signal, rectifies the carrier wave by the power generation circuit 22 and converts it to DC power, and all the circuits in the card To supply. When power is supplied and the control circuit 26 is driven, control is started in accordance with a program stored in the memory device 23. If the IC card 200 conforms to the same standard as described above, the communication method is the load variation method, and the communication relationship with the reader / writer is returned only after recognizing the unique call code from the reader / writer 100. Further, the subcarrier is 847.5 kHz which is 1/16 of the center carrier, the modulation method is ASK of the subcarrier, the encoding method is the NRZ-L method, and the communication speed is 106 kb / s.
Next, the control circuit 26 first demodulates the command from the transmission / reception circuit 21 by the detector 25, converts it to a binary signal, and analyzes the command. As a result, when it is recognized that it is called, the response is modulated by the modulator 24 and transmitted from the loop antenna 20 via the transmission / reception circuit 21.
The reader / writer 100 receives this response with the loop antenna 9, converts it into a binary code with the detector demodulator 8, analyzes it with the control circuit 2, and recognizes that the IC card 200 is a card that conforms to the standard. Accordingly, polling is performed between the reader / writer 100 and the IC card 200 thereafter.
[0010]
【Example】
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 3 is a flowchart for explaining the operation of the first embodiment of the present invention. This will be described with reference to FIGS. In the following, the reader / writer for non-contact IC cards is referred to as reader / writer A, and the reader / writer for single ticket cards is referred to as reader / writer B. First, a host device (not shown) and reader / writers A and B perform an authentication operation (step S1) (details will be described later). Next, the reader / writer A emits radio waves (step S2). Subsequently, the radio wave of the reader / writer B is stopped (step S3). Next, whether or not there is a response in the reader / writer A (step S4), if YES, the card C is communicated (step S5), communication completion is determined (step S6), and if NO, Returning to step S4, if YES, the process returns to step S2. If NO in step S4, it is checked whether there is a response in reader / writer B (step S7). If YES, the radio wave of reader / writer A is stopped (step S8), and the radio wave of reader / writer B is emitted. (Step S9), the card B is communicated (step S10), and communication completion is determined (step S11). If “NO” here, the process returns to the step S7, and if “YES”, the process returns to the step S2. If NO in step S7, the process returns to step S2.
[0011]
FIG. 4 is a flowchart for explaining the operation of the second embodiment of the present invention. This will be described with reference to FIGS. First, a host device (not shown) and the reader / writer A perform an authentication operation (step S20) (details will be described later). Next, the radio wave of the reader / writer A is emitted (step S21). Next, whether or not there is a response in the reader / writer A (step S22), if YES, the card C is communicated (step S23), communication completion is determined (step S24), and if NO, Returning to step S22, if YES, the process returns to step S21. Subsequently, it is checked whether the reader / writer B has a response (step S25). If NO, the process returns to step S21. If YES, the radio wave of the reader / writer A is stopped (step S26). The power is turned on (step S27), and a host device (not shown) and the reader / writer B perform an authentication operation (step S28) (details will be described later). Next, the radio wave of the reader / writer B is emitted (step S29), the card B is communicated (step S30), and the communication completion is determined (step S31). If “NO” here, the process returns to the step S29, and if “YES”, the power supply of the reader / writer B is stopped (step S32), and the process returns to the step S21.
[0012]
FIG. 5 is a flowchart for explaining the operation of the third embodiment of the present invention. This will be described with reference to FIGS. First, a host device (not shown) and reader / writers A and B perform an authentication operation (step S40) (details will be described later). Next, the radio wave of the reader / writer A is emitted (step S41). Next, whether or not there is a response in the reader / writer A (step S42), if YES, the card C is communicated (step S47), communication completion is determined (step S48), and if NO, Returning to step S42, if YES, the process proceeds to step S43. Subsequently, the radio wave of the reader / writer A is stopped (step S43), the radio wave of the reader / writer B is emitted (step S44), whether the reader / writer B has a response (step S45), and if YES, Card B is communicated (step S49), and communication completion is determined (step S50). If “NO” here, the process returns to the step S45, and if “YES”, the process returns to the step S46. If “NO” in the step S45, the radio wave of the reader / writer B is stopped (step S46), and the process returns to the step S41.
[0013]
FIG. 6A is a diagram of a reader / writer initialization sequence, and FIG. 6B is a diagram of a C-type card processing sequence. Hereinafter, in all the embodiments, two types of methods B and C will be described. An initialization sequence of the reader / writer will be described with reference to FIG. First, an attention command (Attention Command) 1 is transmitted from the host device 50 in order to initialize the reader / writer 100. When the reader / writer 100 receives the command, it returns an attention response 2. When the signal is received, an authentication command (1) (Authentication 1) 3 indicating that the reader / writer is desired is transmitted, and a response authentication command (1) response 4 is returned. Subsequently, an authentication command (2) (Authentication1) 5 is transmitted, and a response authentication command (2) response 6 is returned. The reader / writer 100 is authenticated by this series of operations.
Next, the processing sequence of the C type card will be described with reference to FIG. First, polling 10 for type B and C is transmitted from the host device 50. When the reader / writer 100 receives the command, it transmits polling B11 and polling C12 alternately to the C type IC card 200a. The IC card 200a sequentially receives polling sent alternately, and when a polling C12 is received at a certain timing, it returns a polling C response 13 to the reader / writer 100. The reader / writer 100 receives the signal and recognizes that the IC card 200a is of the C type, and at the same time returns a polling C response 14 to the host device 50. When the host device 50 receives this response, communication between the host device 50 and the reader / writer 100 is performed with a packet configuration (not shown).
[0014]
【The invention's effect】
According to the present invention as described above, Claim 1, since the emit radio waves alternately from both writer, another to avoid the influence of noise and reliable communications.
According to the second aspect of the present invention, since the emission time of the alternately emitted radio waves is a time necessary and sufficient for establishing communication, communication can be performed without impairing access time and convenience.
The third aspect recognizes that the reader / writer has been selected by inserting the card, and can therefore stand by with the radio wave and the main power supply stopped.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an IC card reader / writer according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a non-contact type IC card according to an embodiment of the present invention.
FIG. 3 is a flowchart illustrating the operation of the first exemplary embodiment of the present invention.
FIG. 4 is a flowchart illustrating the operation of the second exemplary embodiment of the present invention.
FIG. 5 is a flowchart for explaining the operation of the third embodiment of the present invention.
6A is a reader / writer initialization sequence, and FIG. 6B is a C type card processing sequence.
FIG. 7 is a flowchart for explaining the operation of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission / reception apparatus, 2 Control apparatus, 3 Memory apparatus, 4 Modulator, 5 Input apparatus, 6 Display apparatus, 7 Power amplifier, 8 Detection demodulator, 9 Loop antenna, 10 Random number generator, 50 Computer, 100 Reader / writer.

Claims (3)

A plurality of non-contact type IC card reader / writers that perform non-contact transmission and transmission / reception of carrier power based on a predetermined modulation / demodulation method via a loop antenna of the IC card, and a reader / writer of a type different from the reader / writer In the interference prevention method,
After completion of the authentication operation with the upper device of each reader / writer, the reader / writer emits radio waves of any one of the plurality of reader / writers, and the reader / writer has no response from the non-contact IC card, or When communication with the non-contact IC card is completed, a series of operations for stopping radio waves of the reader / writer is performed, and then the series of operations are repeated for reader / writers other than the reader / writer that have completed the series of operations. The reader / writer interference prevention method is characterized in that all reader / writers are repeated until the series of operations is completed . Wherein both reader radio wave firing time emitted alternately from writer interference preventing method of the reader writer according to claim 1, wherein the communication is a sufficient time required for establishment. The different schemes interrogator interference preventing method of the reader-writer according to claim 1, wherein the insertion of the card is a writer recognize that the writer is selected.

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