JP3370825B2 - Non-contact transponder recognition method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention attaches an ID card to tools and luggage in a production line or distribution line of a factory, entrance / exit management of an office, etc. The present invention relates to a contactless responder recognition method and device for communication and management, in which a unique ID code, product number, manufacturing data, etc. are registered in the contactless responder, and the data is communicated in a contactless manner. Is used to identify the transponder.

[0002]

2. Description of the Related Art FIG. 9 is a schematic diagram showing a usage state of a conventional interrogator, FIG. 10 is an explanatory diagram showing a temporal relation of communication in a transmission / reception state of the interrogator shown in FIG. 9, and FIG. 11 is a communication area. Explanatory drawing when there are a plurality of responders communicating with the interrogator. FIG. 12 is a timing chart for explaining the time relation of communication in FIG. Generally, in this type of interrogator, the usage state as shown in FIG. 9 is adopted. In the conventional non-contact transponder system, the interrogator 1 first sends a high frequency signal for reading to the transponders existing in the communication area. This read signal is a command for the responder, etc.
It is SK-modulated or FSK-modulated. When the transponder receives this read signal, the transponder also generates power for operating all the circuits of the transponder at the same time, and enters the operable state from the so-called sleep mode.
Then, according to the content of the command from the interrogator 1, the ID code and data are read from the memory in the responder, the high frequency signal is modulated and returned.

However, in the conventional non-contact transponder system, it is premised that the interrogator 1 and the transponder communicate in a one-to-one relationship as shown in FIG. The timing chart at this time is as shown in FIG. In this relationship, when the read command is transmitted from the interrogator 1, the responder 2 receives the read command and returns the data. The interrogator 1 receives the data from the responder 2. However, as shown in FIG. 11, the interrogator 1 has a plurality of responders, for example, two responders 2a, 2
When b exists, when the read signals of the interrogator 1 reach a plurality of responders at the same time, interference occurs because the responders try to reply at the same time, as shown in FIG. In the entry / exit management, interference occurs as described above, and the interrogator 1
If it is not possible for the side to discriminate, it is considered an error and the entry / exit is rejected. For that reason, it is unavoidable that the traffic range of the person having the transponder 2 is narrowed to enter the communication area one by one. In addition, a timer is built in the transponder 2, and the timer is started when a read signal is received.
Some responders 2 shift the return time of the reply signal by using the fact that the responder 2 is allowed to transmit when a preset time has elapsed. However, in this method, it is necessary to set the timer of each responder so that the response times do not overlap, so it is difficult to make different settings for all responders when the number of responders increases. is there. Moreover, an accurate timer is required so that the response times of the transponders never overlap.

[0004]

As described above, the problem to be solved by the present invention is that when the read signals of the interrogator arrive at a plurality of responders at the same time, each responder responds at the same time, causing interference. Occurs, and the interrogator side cannot determine.

According to the first aspect of the present invention, when a plurality of responders exist for one interrogator in the same communication area, the responder is surely set without setting the return time for each responder in advance. The purpose of the present invention is to recognize the transponder without interference so that the transponder can be recognized and no special timer setting is required to prevent duplication of the return time from the transponder.

According to a second aspect of the present invention, similarly to the first aspect, when a plurality of responders exist for one interrogator in the same communication area, a return time is set in advance for each responder. The purpose of this is to ensure that the transponder can be recognized without needing to do so, and that no special timer setting is required to prevent duplication of the return time from the transponder, and to recognize the transponder without interference. .

According to a third aspect of the present invention, similarly to the first aspect, when a plurality of responders exist for one interrogator in the same communication area, a return time is set in advance for each responder. The purpose of this is to ensure that the transponder can be recognized without needing to do so, and that no special timer setting is required to prevent duplication of the return time from the transponder, and to recognize the transponder without interference. .

According to a fourth aspect of the present invention, similarly to the first aspect, when a plurality of responders exist for one interrogator in the same communication area, a return time is set for each responder in advance. The purpose of this is to ensure that the transponder can be recognized without needing to do so, and that no special timer setting is required to prevent duplication of the return time from the transponder, and to recognize the transponder without interference. .

[0009]

According to the invention of claim 1, a random bit is transmitted from the interrogator to the responder, and at the responder side, the unique ID code previously held by the responder is set as the random bit. This is a method of sequentially comparing and transmitting response data from the responder to the interrogator when both codes match.

The invention of claim 2 is a method of transmitting a confirmation signal indicating that the interrogator has received the response data to the transponder while the interrogator receives the response data from the transponder.

A third aspect of the present invention is a method in which the data length of the data of the responder to be compared with the random bit generated on the interrogator side is different for each responder.

According to a fourth aspect of the present invention, random bit generating means for supplying random bits to the interrogator is provided, and
The transponder receives the output of the above control means and writes it in the memory.
A shift register that stores the stored unique ID data
And the random bit demodulated by the receiving means of the transponder.
Output signal of the shift register and the predetermined output of the shift register,
When matching, shift the data in the above shift register
And a transmitting means of the responder,
All bits of the unique ID data are randomized by the comparison means.
If it matches with the
It is a thing.

[0013]

According to the invention of claim 1, from the interrogator to the responder,
Random bits are transmitted. On the other hand, on the responder side, the unique ID code held in advance is sequentially compared with the random bits, and when both codes match, the responder sends response data to the interrogator. It

According to the second aspect of the invention, when the interrogator receives the response data from the responder, the confirmation signal indicating that the response data is received is transmitted to the responder.

According to the invention of claim 3, the transmission time of the response data of the responder is automatically changed depending on the data length of the responder which is compared with the random bit generated on the interrogator side.

The invention of claim 4 is the same as that of claim 1,
A random bit is transmitted from the interrogator to the responder,
On the other hand, on the responder side, the unique ID data held in advance is sequentially compared with the random bits to unique ID.
When all the bits of the data match the random bits , the responder transmits the response data to the interrogator.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a state in which the transponder recognition method according to the present invention is embodied as an apparatus. That is, in FIG. 1, reference numeral 1 is an interrogator, and 2 is a transponder that communicates with the interrogator 1 in the communication area 3. The interrogator 1 includes a transmitter 4, a receiver 5, and a signal controller 6.
Composed of. The transmitting means 4 has an oscillating unit 7, a modulating unit 8 and a transmitting unit 9. The output end of the oscillator 7 is connected to the input end of the modulator 8, and the output end of the modulator 8 is connected to the transmitter 9. The receiving means 5 has a receiving unit 10 and a demodulating unit 11 connected to this receiving unit. The signal control means 6 is composed of a CPU and the like. The signal control means 6 is connected to the modulator 8 and the demodulator 11. Reference numeral 12 is a random bit generating means for generating a random bit.

The transponder 2 comprises a receiving means 13, a transmitting means 14,
The control unit 15, the memory 16, the shift register 17, and the comparison unit 18 are included. The receiving means 13 is a receiving unit 19,
It has a power supply unit 20 and a demodulation unit 21. The receiving unit 19 is connected to the power supply unit 20 and the demodulation unit 21. The power supply unit 20 rectifies the high-frequency signal from the interrogator 1 received by the receiving unit 19 into a direct current, stores it in a capacitor or the like (not shown), and uses it as all the power supplies of the responder 2. Is. The power supply unit 20 may have a battery or a solar battery mounted on each responder. The transmitting means 14 includes a modulator 22 and a transmitter 23 connected to the modulator 22.
Have and. Further, the control means 15 includes a demodulator 21 and a modulator 2.
2, memory 16, comparing means 18, and shift register 1
7 are connected respectively. The comparison means 18 includes a demodulation unit 21,
It is connected to the shift register 17 and the control means 15, respectively.

Next, the operation of the above configuration will be described. First, the interrogator 1 uses the modulator 8 to modulate the signal from the oscillator 7 with a command to the responder generated by the signal controller 6. The modulated wave is transmitted to the transmitter 9, and the interrogator 1 sends the signal to the responder 2. On the other hand, the responder 2 stores a unique ID code in the memory 16. When the interrogator 1 sends out a high-frequency signal for starting reading, the receiving unit 19 receives the signal, and a part of the signal is supplied to the power supply unit 20 so that each responder 2 existing in the communication area 3 The operation stop state, so-called sleep state, is changed to the operable state. As a result, the control means 15 resets the shift register 17. Each responder 2 demodulates the read command signal by the demodulator 21, and the control means 15 reads the ID code unique to each responder from the memory 16 and stores it in the shift register 17.

FIG. 2 shows a timing chart in the communication state between the interrogator and the plurality of responders in the configuration of FIG. In FIG. 2, the interrogator 1 sends a read start signal and then sends to the communication area 3 a random bit signal obtained by modulating the high frequency signal from the oscillator 7 with binary random bits. Random bits are generated by the random bit generating means 12 which randomly outputs "0" or "1". The transponder 2 receives the random bit signal in the receiving unit 19, and further demodulates it in the demodulating unit 21 to reproduce the random bit. The output of the demodulation unit 21 is input to the comparison unit 18, and the output of the shift register 17, that is, the exclusive OR (Exc) with the least significant bit or the most significant bit of the ID code.
The positive OR) is taken and compared. When the output of the shift register 17 and the random bit emitted by the interrogator 1 match, the data in the shift register 17 is shifted.

FIG. 3 is an explanatory diagram showing the relationship between the random bit of the interrogator and the ID code held by each responder. In FIG. 3, it is assumed that each transponder 2a, 2b, 2c has an 8-bit ID code within the frame. In this state, the interrogator 1 sequentially sends out random bits within the frame. The responder 2 sequentially compares each ID code with the random bit sent by the interrogator 1. The numbers on the boxes indicate in which bits the interrogator 1 generated random bits with which the outputs of the shift registers matched. Each transponder compares the output of the shift register storing the ID code with the random bit sent by the interrogator 1, and shifts the value of the shift register only when they match. On the other hand, the control means 15
Then, a counter function for counting the number of bits of the ID code of the responder 2 is provided, and counting is performed when a signal indicating that the shift register output and the random bit match is received from the comparison circuit. For example, when the ID code of the responder 2 is 8 bits, the output from the comparison circuit is 8
It is recognized that all the bits of the ID code of the transponder 2 match the random bits at the time of the occurrence. If all 8 bits match, the transponder 2 is ready to send,
Sends data that should be sent. When the data transmission is completed, the responder 2 enters the power-off state, that is, the sleep state again. In FIG. 1, the interrogator 1 and the responder 2
Although both the transmitters 9 and 23 and the receivers 10 and 19 are separated, it is possible to combine these into one. The modulation method is ASK (Amplitude Shift K).
eyeing) modulation and FSK (Frequency Sh)
if keying) modulation, PSK (Phase S)
It is possible to use shift keying modulation or the like.

In FIGS. 2 and 3, the interrogator 1 is 11
At the time of sending the bit, the responder 2a matches all the 8 bits, so that the modulator 22 modulates its own ID code and in-memory data, and transmits it to the interrogator 1 through the transmitter 23. The interrogator 1 does not send the 12th random bit until it receives the reply signal from the responder 2 and recognizes the response data from the responder 2a. When all the response data of the transponder 2 is received and recognized, the interrogator 1 sends out the 12th random bit. ID for all responders 2a, 2b, 2c in communication area 3
The interrogator 1 sends out random bits until the code matches the random bits. When the response from the responder 2 is lost for a certain period of time, it is determined that all the responders 2a, 2b, 2c have returned, and the transmission of the random bit is stopped,
Terminate communication. The value to be compared with the random bit may be a value set in advance in the memory 16 instead of the ID code. The transponder 2 transmits I
Not only the D code but the data held by each responder 2 may be added.

FIG. 4 is a timing chart showing a case where a plurality of transponders are ready to transmit with the same random bit. In FIG. 4, when the random bit radiated by the interrogator 1 is the 11th bit, all the bits of the ID code of the responder 2a and the responder 2b match, and both responders 2a and 2b transmit the response data. However, at the same time, both transponders 2a and 2b radiate a high-frequency signal, so that the interrogator 1 cannot determine the transmission data of both transponders, which is regarded as an interference state. Therefore, the interrogator 1 sends a reset command signal to all responders in the communication area. Upon receipt of the reset command signal, the responders 2a and 2b are controlled by the control means 15
Then, the shift register 17 is reset, and then the control means 15 is used to read the ID code again from the memory 16. On the other hand, the responder 2c determines that the reset command signal is not the signal for itself because the responder 2c is not transmitting data, and maintains the comparison state as it is.

The interrogator 1 sends a random bit signal again, and each responder makes a comparison. In FIG. 4, the responder 2c
, The data is transmitted because all the ID codes match at the 12th bit, and the interrogator 1 can determine the data of the responder 2c because there is no other responder outputting the data. Since there is no reset command signal after the data is transmitted, the responder 2c determines that communication can be performed without interference, and the transponder 2c enters the sleep state, that is, the sleep mode again. Hereinafter, by repeating this operation, the interrogator 1 can normally receive the data of all the responders without overlapping. When the shift register 17 is reset, it is possible to shorten the re-comparison time by inputting a divided ID code instead of inputting all the ID codes again.

FIG. 5 is a flow chart for explaining the operation of FIG. Here, first, it is assumed that 2a is selected first in the transponder 2. First, the responders 2a and 2b are in the sleep mode (ST0).
In this state, the interrogator 1 emits a read start signal including a command signal (ST1). The responders 2a and 2b receive the command signal and demodulate it (ST2). Next, the responders 2a and 2b read the ID code from the memory 16 and input it to the shift register 17 (ST3). The interrogator 1 transmits random bits to the responders 2a and 2b (ST4). The transponders 2a and 2b are the shift register 1
The output of 7 and the random bit are compared (ST5). Eventually, all the ID codes of the responder 2a match (ST6). Then, the responder 2a transmits the response data in the memory 16 (ST7). When the interrogator 1 receives the data from the responder 2a, it stops transmitting random bits (ST8). On the other hand, the transponder 2a that has completed the transmission enters the sleep mode (S
T9). The interrogator 1 demodulates and recognizes the data of the responder 2a (ST10). Here, the responder 2b changes from ST6 to S
Until T10, the random bit from the interrogator 1 is on standby. The interrogator 1 transmits the random bit again (ST11). This time, for example, all the ID codes of the responder 2b and the random bits from the interrogator 1 match (ST
12). Similarly, the responder 2b transmits the response data in the memory 16 (ST13). The interrogator 1 receives the data from the responder 2b and stops the transmission of random bits (ST14). On the other hand, the transponder 2b, which has completed the transmission, enters the sleep state (ST15). The interrogator 1 demodulates and recognizes the data of the responder 2b (ST16).

Here, a plurality of transponders 2 are provided in the communication area 3.
a, 2b, and 2c exist, and when data transmission is performed by the above method, as shown in FIG. 6, the responder 2a near the interrogator 1 and the responder 2b at the end of the communication area are at the same time. Data may be returned. In this case, the responder 2a located closer to the interrogator 1 than the return signal of the responder 2b
7, the interrogator 1 may demodulate and recognize only the data of the responder 2a without considering it as interference, as shown in FIG. Therefore, the interrogator 1 does not radiate the reset command signal indicating the interference to the communication area. Therefore, not only the responder 2a but also the responder 2b determines that the interrogator 1 can normally communicate. Therefore, when the interrogator 1 correctly recognizes the transmission data of one responder, it is conceivable to transmit a confirmation signal to the responding device that has returned, indicating that normal communication was successful. An example of the apparatus in that case is shown in FIG. At this time, the interrogator 1 transmits the ID code or the like of the transponder recognized as the confirmation signal so that the transponder 2 can determine that the reply signal can be recognized on the interrogator 1 side by the confirmation signal. As a result, the transponder 2b, which is located away from the interrogator 1, becomes ready to transmit data and transmits data. However, if the confirmation signal emitted from the interrogator 1 is the ID code of the transponder 2a, it is sent by itself. It is possible to understand that the data that was made was not recognized. Therefore, the data is transmitted again or the shift register 17 is reset and the ID code is stored in the memory 1
Read from 6, and compare again with the random bit.

Incidentally, among the transponders, the transponders existing in the communication area 3 and having not yet returned the data also receive the confirmation signals, so that the interrogator 1 sends the confirmation signals to those transponders by random bits. Different codes or different transmission frequencies are used so that they are not misjudged as signals. On the other hand, in the transponder which has transmitted the data, the demodulation circuit is switched from the random bit signal to the one capable of demodulating the confirmation signal so that the confirmation signal can be judged by using the switch 26 shown in FIG. It is also possible to perform demodulation by the same demodulation circuit and determine by the control means 15 as shown in FIG. 1 by setting a code for distinguishing between the random bit signal and the confirmation signal for both signals.

Further, the transponder 2 is the interrogator 1 so that the probability of returning simultaneously in a plurality of transponders is smaller.
It is conceivable to increase the data length of the data such as the ID code to be compared with the random bit transmitted by the, or to make the data length of the ID code to be compared different in each responder 2. In this case, the data length of the above data may be variably set depending on the maximum number of transponders entering the communication area 3. This reduces the probability that a plurality of transponders will simultaneously return the response data, and enables communication with all transponders within the communication area in a short time. The responder compares the random bits from the interrogator 1 with 2 bits (“0
0 "," 01 "," 10 "," 11 ") or 3 bits at a time makes it possible to produce the same effect.

[0029]

According to the invention of claim 1, the interrogator transmits a random bit to the responder, and at the responder side, the data such as a unique ID code which the responder has in advance is sequentially transmitted with the random bit. By comparing and responding data is sent from the transponder to the interrogator when all bits match, it is not necessary to set the return time for each responder in advance, and the return time is not duplicated. No need to have an accurate timer for. Therefore, when there are a plurality of transponders in the communication area, there is no interference and it is possible to communicate with all the transponders.

According to the second aspect of the present invention, the interrogator transmits the confirmation signal indicating that the response data has been received to the responder in the state where the interrogator receives the response data from the responder. In addition to having the same effect as that of claim 1, it is possible to determine whether or not the transponder that has transmitted the response data can normally communicate with the interrogator, and further high reliability can be obtained. And so on.

According to the invention of claim 3, the data length of the peculiar data of the responder to be compared with the random bit generated on the interrogator side is different for each responder, so that the same effect as that of claim 1 is obtained. In addition, it is possible to reduce the probability that the response time of the response data for each responder collides, and it becomes possible to communicate with all the responders existing in the communication area in a short time without interference. effective.

According to the invention of claim 4, the interrogator is the interrogator described above.
Random bits to supply random bits to the transmission means of
Generating means are provided, while the responder is provided with the control means.
When the output is received, the unique ID data stored in the memory is stored.
It is restored by the shift register to be stored and the receiving means of the responder.
Adjusted random bit signal and shift register
The output of the shift register
The above-mentioned response is provided with a comparison means for shifting the data
The transmitting means of the container is the ID data unique to the comparing means.
Can be sent when all bits match the above random bits
Since it is configured to be in the Noh state, as in claim 1,
It is not necessary to set the return time for each transponder in advance,
Also, it is not necessary to set an accurate timer to prevent the return time from overlapping. Therefore, when there are a plurality of transponders in the communication area, there is no interference and it is possible to communicate with all the transponders.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a method for recognizing a contactless transponder and an apparatus therefor according to the present invention.

FIG. 2 is a timing chart in a communication state between an interrogator and a plurality of responders in the configuration of FIG.

FIG. 3 is an explanatory diagram showing a relationship between random bits of an interrogator and an ID code held by each responder in the configuration of FIG. 1.

FIG. 4 is a timing chart showing a case where a plurality of transponders are ready to transmit with the same random bit in the configuration of FIG.

FIG. 5 is a flowchart for explaining the operation of FIG.

FIG. 6 is an explanatory diagram showing an example of use of confirmation signals in a positional relationship of a plurality of responders with respect to an interrogator.

FIG. 7 is a timing chart showing the response states of a plurality of responders in response to the interrogator read command in FIG. 6;

FIG. 8 is a block diagram showing another embodiment of the method for recognizing a contactless transponder and the apparatus therefor according to the present invention.

FIG. 9 is a schematic diagram showing a usage state of a conventional interrogator.

10 is a timing chart showing a communication state between an interrogator and a responder in the responder recognition device shown in FIG.

FIG. 11 is an explanatory diagram showing a relationship between an interrogator and a transponder when a plurality of transponders exist in one communication area.

FIG. 12 is a timing chart illustrating a temporal relationship of communication in FIG.

[Explanation of symbols]

1 Interrogator 2 responder 4,14 Transmission means 5,13 Receiving means 6 Signal control means 12 Random bit generation means 15 Control means 16 memory 17 shift register 18 Comparison means

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B42D 15/10 501 G06K 17/00 G06K 19/07

Claims (4)

(57) [Claims] 1. In a device for transmitting command data from an interrogator to a responder and transmitting response data from the responder to the interrogator in response to the command data, a unique response of the responder In the arrangement direction of the bits of the data, first, the first bit of the unique data is used as a reference to sequentially compare with the random bit sent from the interrogator, and the random bit is compared with the first bit of the bits of the unique data. When there is a match, the first bit of the data of the responder is shifted, and then, in the arrangement direction of the unique data, the bit next to the first bit adjacent to the first bit of the responder is used as a reference and The random bit from the interrogator is compared, and when this random bit matches the next bit of the unique data, the next bit of the unique data is In the same manner, each bit of the unique data is compared with the random bit, and when they match, the data bits of the responder are all shifted to the last bit. A method for recognizing a non-contact transponder in which a transponder that has completed this shift transmits data for response to the interrogator when the data can be returned. 2. The contactless response according to claim 1, wherein the interrogator receives a response data from the responder and transmits a confirmation signal indicating that the response data is received to the responder. Recognition method. 3. The method for recognizing a non-contact transponder according to claim 1, wherein the data length of the unique data of the transponder to be compared with the random bit is different for each transponder. 4. A signal control means, the interrogator having transmission means and receiving means, receiving means for receiving a signal from the interrogator, and control means for controlling signals from the receiving means, the response Means for transmitting data for use, and unique ID
A device comprising a transponder having a memory for storing data including data, wherein the interrogator is provided with random bit generating means for supplying random bits to the transmitting means of the interrogator, while the responder is provided with , store the unique ID data stored in the memory in response to an output of the upper Symbol control means
Demodulation by the shift register and the receiving means of the transponder
The random bit signal and the specified shift register
The output of the above shift register
And a responding means for shifting the date of
The means for transmitting the
Can be sent when the bit matches the random bit above
A non-contact responder recognition device characterized by being in a state .