JP2000252855A - Accessing method for transponder, and transponder reader and trasnponder system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an access method for a transponder by which a plurality of transponder that can be manufactured at a low cost and use a plurality of electromagnetic waves can be accessed nearly at the same time, to provide a transponder reader and a transponder system. SOLUTION: In this transponder access method, a system using a plurality of transponder TP-1 to TP-n using a frequency of a 135 kHz band, and using a transponder reader is configured. Furthermore, times (t1-tn) until the transmission of a response signal is started after a 30ms questionnaire signal is received by each of the plurality of the transponders TP-1 to TP-n are set at random within 35ms-295ms. After the transponder reader TRD transmits a questionnaire signal once, the transponder reader TRD maintains a reception state for at least 300ms to receive a response signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transponder reader and a transponder system capable of accessing a plurality of transponders using a frequency lower than a medium wave band substantially simultaneously.

[0002]

2. Description of the Related Art In recent years, a method has been used in which individual information of a tire is stored in a storage means of the transponder, for example, by embedding a transponder in a tire, and the tire is managed using this information. Have been.

[0003] By managing tires and the like using the transponder in this way, a large amount of information to be managed can be processed in a short time and with high accuracy, so that management work can be saved and errors can be generated. Can be prevented.

As a transponder transmission / reception frequency used in this case, a frequency in the 2.45 GHz band is generally used at present in consideration of a communication speed, that is, an information transmission amount.

[0005]

However, since the transmitting / receiving circuit of the ultrahigh frequency such as the 2.45 GHz band is very susceptible to the surrounding environment, it is necessary to pay close attention to the circuit design and manufacture of the transponder. Therefore, it was difficult to reduce the manufacturing cost.

[0006] For this reason, a tire in which the above-mentioned transponder is embedded becomes more expensive than a normal tire.
Popularization is lagging.

[0007] In addition, the transponder can be used in the product management and the like currently performed using barcodes and the like, similarly to the above-described tire management. However, at present, the transponder having the frequency of 2.45 GHz band is used. Since it is the mainstream, the cost is high, so it is hardly practically used at present.

Further, transponders using electromagnetic waves having a low frequency in the middle-wave band or lower, for example, transponders using electromagnetic waves of 135 KHz, are relatively low in cost because they are relatively easy to design and manufacture. But,
Since the frequency is low, the communication speed is lower than that using ultrahigh frequency waves, so that it is difficult to access a plurality of transponders almost simultaneously, and it is used only for single access.

If it becomes possible to access a plurality of transponders using electromagnetic waves having a low frequency in the middle wave band or lower which can be manufactured at a low cost almost simultaneously, tires and other merchandise management using the transponders will be widely spread. Therefore, there is a long-awaited need for a device and a system that can realize this.

In view of the above problems, it is an object of the present invention to provide a transponder access method, a transponder reader, and a transponder system that can access a plurality of transponders using electromagnetic waves having a low frequency in the middle-wave band or lower that can be manufactured at low cost. Is to provide.

[0011]

In order to achieve the above object, according to the present invention, an electromagnetic wave of a predetermined frequency equal to or lower than a medium wave band is used, and a response signal is generated when an electromagnetic wave serving as an interrogation signal is received. For a plurality of transponders to transmit, a transponder access method for transmitting an interrogation signal from a transponder reader and receiving a response signal from the plurality of transponders, wherein each of the plurality of transponders receives an interrogation signal , The time from when the transmission of the response signal is started is set at random within a predetermined dispersion time, and the transponder reader transmits at least the dispersion time and one response signal transmission after transmitting the interrogation signal once. Proposes a transponder access method that receives the response signal while maintaining the reception state during the time that the time is added That.

According to the transponder access method, the time from when the interrogator receives the interrogation signal to when the transponder starts transmitting the response signal is randomly set within a predetermined dispersion time. The transmission timing of the response signal from each transponder becomes random, and the response signals from a plurality of transponders can be separated and received.

According to a second aspect of the present invention, in the transponder access method according to the first aspect, the transponder reader is provided with two or more transmitting / receiving antennas arranged at different positions from each other, and switching the transmitting / receiving antennas in order. A transponder access method for transmitting the interrogation signal and receiving the response signal is proposed.

According to the transponder access method, since two or more transmitting and receiving antennas are provided, the positional relationship between these transmitting and receiving antennas and each of the plurality of transponders, the distance, the shields existing between them, etc. Is different for each transmitting and receiving antenna. For this reason, if the transmitting and receiving antennas to which the electromagnetic waves of the interrogation signal are transmitted are different, the timing at which each transponder receives the electromagnetic waves of the interrogation signal changes, so that the transmission timing of the response signal from the transponder also differs. Accordingly, even when the time from when the interrogation signal is received by two or more transponders to when the transmission of the response signal is started coincides,
Response signals from these transponders can be separated and received.

According to a third aspect of the present invention, in the transponder access method according to the first aspect, the time from when the transponder receives the interrogation signal to when transmission of the response signal is started is set to a different value for each transponder. We propose an access method of the transponder to be executed.

According to the transponder access method, the time from when the transponder receives the interrogation signal to when transmission of the response signal is started is set to a different value for each transponder, so that two or more transponders can access the transponder. , The probability that the transmission timings of the response signals coincide with each other can be reduced.

According to a fourth aspect of the present invention, in the transponder access method according to the third aspect, at least one of the plurality of transponders is configured to set at least a time period from when the interrogation signal is received to when the transmission of the response signal is started to at least the response signal. We propose a transponder access method that is set to have a difference of a natural number times the transmission time.

According to the transponder access method, when a transponder reader receives a response signal, the probability that some or all of two or more response signals overlap can be reduced.

According to a fifth aspect of the present invention, in the transponder access method according to the first aspect, the number of transponders to be accessed is set in the transponder reader, and the transponder reader responds from all the transponders to be accessed. A transponder access method that repeats transmission of an interrogation signal at the transmission timing until a signal can be received is proposed.

According to the transponder access method, the transmission of the interrogation signal is repeated until the number of response signals received from different transponders reaches the number of transponders to be accessed. A response signal from the transponder can be obtained without omission.

According to a sixth aspect of the present invention, in the transponder access method according to the first aspect, a transponder access method using a 135 KHz band as the frequency of the electromagnetic wave is proposed.

According to the transponder access method, communication using a 135 kHz band electromagnetic wave is performed between the transponder and the transponder reader.

According to a seventh aspect of the present invention, an interrogation signal is transmitted to a plurality of transponders which transmit a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band. In a transponder reader for receiving a response signal, two or more transmitting / receiving antennas arranged at different positions from each other, and transmitting an electromagnetic wave of an interrogation signal via the transmitting / receiving antenna for a predetermined transmission time when receiving a transmission command. A transmitting / receiving unit that maintains a receiving state and outputs a received response signal as an electric signal except when transmitting an interrogation signal, and connects the transmitting / receiving unit to the plurality of transmitting / receiving antennas in order at predetermined time intervals. Antenna switching means for switching, transmission / reception control means for transmitting the transmission command to the transmission / reception section at every predetermined time interval, An information extraction unit that inputs a plurality of response signals output from the transmission / reception unit and extracts predetermined information included in each of the plurality of response signals, and a display unit that displays the information extracted by the information extraction unit. Propose a transponder reader equipped.

According to the transponder reader, the connection of the transmitting / receiving unit is switched to the plurality of transmitting / receiving antennas by the antenna switching unit, and when the transmitting / receiving unit sequentially outputs the transmitting command to the transmitting / receiving unit, the transmitting / receiving command is received. The transmitting / receiving section enters the receiving state after transmitting the electromagnetic wave of the interrogation signal for a predetermined transmission time.

The transponder having received the electromagnetic wave of the interrogation signal transmits a response signal. The response signal is received by the transmission / reception unit in a receiving state, predetermined information included in the response signal is extracted by the information extracting unit, and the extracted information is displayed by the display unit.

Further, since two or more transmitting / receiving antennas are provided, the positional relationship between the transmitting / receiving antenna and each of the plurality of transponders, the distance, and the shields existing between the transmitting / receiving antennas are different for each transmitting / receiving antenna. Become. For this reason, if the transmitting and receiving antennas to which the electromagnetic waves of the interrogation signal are transmitted are different, the timing at which each transponder receives the electromagnetic waves of the interrogation signal changes, so that the transmission timing of the response signal from the transponder also differs. Thereby, the response signals from the plurality of transponders can be separated and received.

According to the present invention, an interrogation signal is transmitted to a plurality of transponders which transmit a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band. In a transponder reader for receiving a response signal, two or more transmission / reception antennas arranged at different positions from each other, and provided for each of the transmission / reception antennas, to transmit an electromagnetic wave of an interrogation signal for a predetermined transmission time when receiving a transmission command. Transmit via the transmitting and receiving antenna, a plurality of transmitting and receiving units that output the received response signal as an electrical signal while maintaining the receiving state except when transmitting the interrogation signal, in order to the plurality of transmitting and receiving units Transmission / reception control means for transmitting the transmission command at predetermined time intervals, and a plurality of response signals output from the plurality of transmission / reception units, We propose an information extracting means for extracting a predetermined information contained in each of the answer signal, the transponder reader and display means for displaying the information extracted by the information extraction means.

According to the transponder reader, when transmission / reception commands are sequentially output to each transmission / reception unit by the transmission / reception control means, the transmission / reception unit receiving the transmission / reception command transmits the electromagnetic wave of the interrogation signal only for a predetermined transmission time. It will be in a receiving state later.

The transponder which has received the electromagnetic wave of the interrogation signal transmits a response signal. The response signal is received by the transmitting / receiving section in the receiving state, the predetermined information included in the response signal is extracted by the information extracting means, and the extracted information is displayed by the display means.

Further, since two or more transmitting / receiving antennas and two or more transmitting / receiving units are provided, the positional relationship between the transmitting / receiving antenna and each of the plurality of transponders, the distance, and the obstacles between them are different for each transmitting / receiving antenna. Will be different. For this reason, if the transmitting and receiving antennas to which the electromagnetic waves of the interrogation signal are transmitted are different, the timing at which each transponder receives the electromagnetic waves of the interrogation signal changes, so that the transmission timing of the response signal from the transponder also differs. Thereby, the response signals from the plurality of transponders can be separated and received.

According to a ninth aspect of the present invention, in the transponder reader according to the seventh or eighth aspect, access target number setting means for setting the number of transponders to be accessed almost simultaneously, and identification information unique to each transponder from the response signal. And a transmission repetition means provided with transmission repetition means for repeating transmission to the transmission / reception control means until the number of the extracted different pieces of identification information reaches the number set by the access target number setting means. suggest.

According to the transponder reader, the transmission of the interrogation signal by the transmission / reception control unit is repeated until the number of different identification information extracted from the response signal reaches the number set by the access target number setting unit. Therefore, it is possible to acquire response signals from all transponders to be accessed without omission.

According to a tenth aspect of the present invention, there is provided the transponder reader according to the seventh or eighth aspect, further comprising an information output unit that outputs information extracted by the information extraction unit to an external device.

According to the transponder reader, the information extracted by the information extracting means can be output to the external device by the information output means, so that the extracted information can be effectively used in the external device.

An eleventh aspect of the present invention proposes the transponder reader according to the seventh or eighth aspect, further comprising an information storage means for storing the information extracted by the information extracting means.

According to the transponder reader, since the information extracted by the information extracting means is accumulated and stored by the information storing means, the accumulated information can be displayed and used.

According to a twelfth aspect of the present invention, there is provided the transponder reader according to the eleventh aspect, further comprising a storage information output unit that outputs information stored in the information storage unit to an external device.

According to the transponder reader, the information stored in the information storage means can be output to the external device by the storage information output means.
The stored extraction information can be effectively used in the external device.

Further, in claim 13, claims 7 to 12
The transponder reader according to any one of the above, has a hand-held type housing, and the transmitting / receiving antenna proposes a transponder reader mounted on the housing.

According to the transponder reader, since the transponder reader has a hand-held type casing, the transponder reader can be carried and used by an operator.

According to a fourteenth aspect, a plurality of transponders for transmitting a response signal when an electromagnetic wave serving as an interrogation signal is received using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band,
In a transponder system including a transponder reader that transmits an interrogation signal to these transponders and receives a response signal, the transponder reader includes a transmitting / receiving antenna and an electromagnetic wave of the interrogation signal when receiving a transmission command. A transmission / reception unit that transmits through the transmission / reception antenna for a predetermined transmission time, maintains a reception state except when transmitting an interrogation signal, and outputs a received response signal as an electric signal; Transmission / reception control means for transmitting an instruction, access target number setting means for setting the number of transponders to be accessed almost simultaneously, and identification information unique to each transponder extracted from the response signal; The number reaches the number set by the access target number setting means. Transmission repetition means for repeating transmission to the transmission / reception control means, and information extraction means for inputting a plurality of response signals output from the transmission / reception unit and extracting predetermined information included in each of the plurality of response signals And display means for displaying the information extracted by the information extraction means, wherein the transponder is a response delay means for starting transmission of a response signal after a predetermined delay time has elapsed after receiving the electromagnetic wave of the interrogation signal. And a transponder system in which the delay time of the response delay means of each transponder is set to a random value within a predetermined time.

According to the transponder system, when transmission / reception commands are sequentially output to the respective transmission / reception units by the transmission / reception control means, the transmission / reception unit receiving the transmission / reception command transmits the electromagnetic wave of the interrogation signal only for a predetermined transmission time. It will be in a receiving state later.

The transponder having received the electromagnetic wave of the interrogation signal transmits a response signal. The response signal is received by the transmitting / receiving section in the receiving state, the predetermined information included in the response signal is extracted by the information extracting means, and the extracted information is displayed by the display means.

The transmission timing of the response signal by each transponder is a random timing by the response delay means in each transponder. Thereby, the response signals from the plurality of transponders can be separated and received.

Further, the transmission of the interrogation signal by the transmission / reception control means is repeated until the number of different identification information extracted from the response signal reaches the number set by the number-of-access-objects setting means. Even when response signals from a plurality of transponders temporarily overlap depending on the state or the like, this can be avoided by repeating the transmission of the interrogation signal, and the response signals from all the transponders to be accessed can be obtained without omission. .

According to a fifteenth aspect, a plurality of transponders that transmit a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band,
A transponder system including a transponder reader that transmits an interrogation signal to these transponders and receives a response signal, wherein the transponder reader according to any one of claims 1 to 5 is used as the transponder reader, The transponder has response delay means for starting transmission of a response signal after a predetermined delay time has elapsed after receiving the electromagnetic wave of the interrogation signal, and the delay time of the response delay means of each transponder is random within a predetermined time. We propose a transponder system that is set to a value.

According to the transponder system, when transmission / reception commands are sequentially output to the transmission / reception units by the transmission / reception control means of the transponder reader, the transmission / reception unit receiving the transmission / reception commands transmits the electromagnetic wave of the interrogation signal for a predetermined transmission time. Is transmitted, and then enters the receiving state.

The transponder that has received the electromagnetic wave of the interrogation signal transmits a response signal. The response signal is received by the transmitting / receiving section in the receiving state, the predetermined information included in the response signal is extracted by the information extracting means, and the extracted information is displayed by the display means.

Further, since two or more transmitting / receiving antennas and two or more transmitting / receiving units are provided, the positional relationship between the transmitting / receiving antenna and each of the plurality of transponders, the distance, and any obstacles between them are different for each transmitting / receiving antenna. Will be different. For this reason, if the transmitting and receiving antennas to which the electromagnetic waves of the interrogation signal are transmitted are different, the timing at which each transponder receives the electromagnetic waves of the interrogation signal changes, so that the transmission timing of the response signal from the transponder also differs. Thereby, the response signals from the plurality of transponders can be separated and received.

The transmission timing of the response signal by each transponder is a random timing by the response delay means in each transponder. Thereby, the response signals from the plurality of transponders can be separated and received.

Further, the transmission of the interrogation signal by the transmission / reception control unit is repeated until the number of different identification information extracted from the response signal reaches the number set by the access target number setting unit. Even when response signals from a plurality of transponders temporarily overlap depending on the state or the like, this can be avoided by repetition, and response signals from all transponders to be accessed can be obtained without omission.

According to claim 16, claim 14 or 1
5. The transponder system according to claim 5, wherein a delay time of the response delay unit is set to a different value for each transponder.

According to the transponder system, since the delay time is set to a different value for each transponder, the rate at which response signals from the transponders are received overlapping can be reduced.

According to claim 17, claim 14 or 1
5. The transponder system according to claim 5, wherein the response delay unit transmits the response signal when the electric energy stored by the electric storage unit reaches a predetermined value, wherein the response delay unit stores the electromagnetic wave energy of the interrogation signal with a predetermined time constant. The present invention proposes a transponder system including a response transmission unit, wherein the delay time is set by the time constant.

According to the transponder system, the transmission timing of the response signal in each transponder can be changed very easily by changing the time constant of power storage in the power storage means of the transponder.

According to claim 18, claim 14 or 1
5. The transponder system according to claim 5, wherein a delay time of each transponder is set to have a difference of at least a natural number times a response signal transmission time.

According to the transponder system, the response signals transmitted from the transponders do not theoretically overlap each other, and the probability that the response signals from the transponders are received overlapping can be greatly reduced.

In claim 19, claim 14 or 1
5. The transponder system according to claim 5, wherein the interrogation signal and the response signal have a frequency of about 135 KHz.

According to the transponder system, communication using a 135 kHz band electromagnetic wave is performed between the transponder and the transponder reader.

[0060]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a transponder system according to a first embodiment of the present invention, FIG. 2 is a block diagram showing an electric circuit of the transponder, and FIG. 3 is a block diagram showing an electric circuit of a transponder reader. It is.

In FIG. 1, TP (TP-1 to TP-n (n
Is a natural number)) is a transponder using an electromagnetic wave having a frequency equal to or lower than the medium wave band, and TRD is a transponder reader.

In the present embodiment, for example, the transponder reader TRD is used without opening a package in which a plurality of products equipped with the transponders TP-1 to TP-n on which product information is recorded are packed together. A transponder system capable of reading product information stored in individual transponders TP-1 to TP-n in a package almost simultaneously will be described.

Each of the transponders TP-1 to TP-n performs transmission / reception at a predetermined same frequency in, for example, a 135 kHz band, and receives an electromagnetic wave serving as an interrogation signal continuously transmitted for 30 ms from the transponder reader TRD. Then, after a predetermined time (delay time), a response signal is transmitted for 3 ms. The delay time is set randomly between 35 ms and 295 ms.

In this embodiment, the transponders TP-1 to TP-1
The configuration shown in FIG. 2 was adopted as one configuration example of TP-n. That is, in FIG. 2, reference numeral 10 denotes a transponder, which is an antenna line 11, a rectifier circuit 12, a central processing unit 13, a storage unit 14,
It comprises a transmitting section 15 and a changeover switch 16.

The rectifier circuit 12 includes a diode 121 and a resistor 1
22 and a capacitor 123 to form a well-known half-wave rectifier circuit. An antenna line 11 is connected to the input side of the rectifier circuit 12 via a changeover switch 16, rectifies a high-frequency current induced in the antenna line 11, converts the high-frequency current into a DC current, and outputs the signal to a central processing unit 13, a storage unit 14, and a transmitting unit. It is output as a drive power supply for the unit 15.

The central processing unit 13 comprises a well-known CPU 131 and a digital / analog (hereinafter referred to as D / A) conversion circuit 132. The CPU 131 makes the voltage Vc output from the rectification circuit 12 reach a predetermined reference value. Start operation when done. When the supply voltage Vc reaches the reference value, the CPU 131
It operates based on a program stored in a storage unit 14 composed of a semiconductor memory such as an EEPROM, and first sets a changeover switch to a transmission state, connects the antenna line 11 to the transmission unit 15, and then sets a predetermined response signal. Is output to the transmission unit 15 via the D / A conversion circuit 132.

Here, information stored in advance in the storage unit 14 is transmitted as a response signal. In this embodiment,
Identification information unique to each of the transponders TP-1 to TP-n, information on the above-described product manufacturing factory, manufacturing date, product code, and the like are stored in the storage unit 14 in advance. Sent as

The transmitting section 15 includes an oscillation circuit 151 and a modulation circuit 152.
And a high-frequency amplifier circuit 153.
Based on the response signal input from the controller, the 135 kHz carrier wave oscillated by the oscillation circuit 151 is modulated via the modulation circuit 152, and supplied to the antenna line 11 via the high frequency amplification circuit 153.

The changeover switch 16 is connected to the CPU 13
When 1 is in a non-operation state, the antenna line 11 and the rectifier circuit 12 are connected, and the antenna line 11 and the transmitting unit 15 are connected only while the switching signal is output from the CPU 131.

Further, in this embodiment, the time constant (= R × C) when the resistance value of the resistor 122 in the rectifier circuit 12 is R and the capacitance of the capacitor 123 is C is randomly set within a predetermined range. By setting, the time from the irradiation of the electromagnetic wave of the interrogation signal to the antenna line 11 until the output voltage of the rectifier circuit 12 (the charging voltage of the capacitor 123) reaches the reference value is set at random between 35 ms and 295 ms. ing. The tolerance of the normally used resistor 122 and capacitor 123 as a product is about 3%. Even when a plurality of transponders use the same value of resistor 122 and capacitor 123, this error is sufficient for the above condition. Will be satisfied.

Next, the configuration shown in FIG. 3 was adopted as the transponder reader TRD in the present embodiment.
That is, in FIG. 3, reference numeral 20 denotes a transponder reader, which includes a transmitting / receiving antenna 21, a transmitting / receiving unit 22, and a central processing unit 2.
3, storage unit 24, display unit 25, operation unit 26, power supply unit 27
It is composed of

The transmission / reception unit 22 outputs a carrier of 135 KHz to the transmission / reception antenna 21 for only 30 ms when receiving a transmission command from the central processing unit 23, and otherwise maintains the reception state to keep the transponders TP-1 to TP- It receives the response signal from n and outputs the received response signal to the central processing unit 23 as digital data.

The central processing unit 23 comprises a well-known CPU, and comprises a storage unit 2 comprising a semiconductor memory such as an EEPROM.
4 operates on the basis of the program stored in the control unit 4, outputs a transmission command to the transmission / reception unit 22 when the trigger switch 262 of the operation unit 26 is turned on, and stores the response signal input from the transmission / reception unit 22 in the storage unit. 24, and extracts predetermined information from the response signal and displays it on the display unit 25.

The operation unit 26 includes a keyboard 261 for inputting commands and the like to the central processing unit 23 and a trigger switch 262 composed of a momentary switch.

The transponder reader 20 is incorporated in a pistol-shaped, hand-held casing 1 as shown in FIG. 4, for example. The transmitting / receiving antenna 21 is arranged at the tip of the housing 1, the keyboard 261 and the display unit 25 are arranged on the upper surface, and the trigger switch 262 is arranged at the trigger position in front of the grip 1a.

Next, the operation of the transponder system having the above configuration will be described.

Before using this system, the number of transponders TP to be accessed almost simultaneously is set in the transponder reader TRD. Here, "access almost simultaneously" means that the transmission and reception of the interrogation signal and the response signal with all of the plurality of transponders TP are completed within about one second or shorter.

For example, when ten products are contained in one package, and the transponder TP is attached to each of these ten products, the stored information of the ten transponders in one package is almost completely stored. The transponder reader TRD is set to read simultaneously. Thus, the storage information of the ten transponders in the package is displayed on the display unit 25 only by turning on the trigger switch 262 once with the tip of the transponder reader TRD facing the target package.

Next, details of the above operation will be described with reference to the transponder reader operation flowchart of FIG. 5 and the transmission / reception operation timing chart of FIG.

In the transponder reader TRD, when the operation is started, the central processing unit 23 initializes the number of access targets, that is, the number N of transponders TP to be accessed almost simultaneously to "1" (SA1). Thereafter, when the operator changes the setting of the number of access targets N via the keyboard 261, the central processing unit 23 changes the number of access targets N (SA2).

Next, the central processing unit 23 determines whether or not the trigger switch 262 has been turned on (SA3).
2 and the transmitting / receiving unit 22 transmits the electromagnetic wave of the interrogation signal via the transmitting / receiving antenna 21 for 30 ms (SA4).
Thereafter, the central processing unit 23 performs a response signal receiving process (SA5).

The electromagnetic wave of the interrogation signal transmitted from the transponder reader TRD is input to the antenna line 11 of the transponder TP, and a high-frequency current is induced in the antenna line 11. The high-frequency current induced in the antenna wire 11 is rectified by the rectifier circuit 12 and has the above-described time constant (= R × C).
Stores the capacitor 123. When the terminal voltage Vc of the capacitor 123 reaches the reference value, the CPU 131 starts operating.

Since the time constants of the transponders TP-1 to TP-n are set at random as described above, the response signal is transmitted after the electromagnetic wave of the interrogation signal is transmitted as shown in FIG. Time (delay time) t1 to tn
Is different in each of the transponders TP-1 to TP-n.

The CPU 131 that has started the operation is
It operates based on the program stored in the antenna line, and first sets the changeover switch to the transmission state to set the antenna line 1
After connecting 1 to the transmitting unit 15, a response signal is output to the transmitting unit 15 via the D / A conversion circuit 132. As a result, response signals are transmitted at different timings from each of the transponders TP-1 to TP-n.

This response signal is received by the transmitting / receiving section 22 of the transponder reader TRD in the receiving state.
After being converted into digital data, it is output to the central processing unit 23.

The central processing unit 23 waits until the elapsed time from the transmission of the electromagnetic wave of the interrogation signal reaches the maximum reception time (S
A6) The information included in the response signal is extracted and sequentially stored in the storage unit 24. In the present embodiment, the maximum reception time is set to 300 ms.

When the maximum reception time has elapsed, the central processing unit 2
No. 3 counts the number of different response signals that can be received (SA7) and determines whether or not this is equal to the number N of access targets (SA8).

If the result of this determination is that the number of response signal reception completions does not reach the number of access targets N, the process proceeds to SA4 and repeats the transmission of the inquiry signal and the reception of the response signal again. When all the response signals of the number N of access targets are received, the central processing unit 23 extracts information such as identification information, a manufacturing factory, a manufacturing date, a product code, and the like from the received response signals and displays the extracted information. (SA9).

If all of the response signals cannot be received even after repeating the transmission of the interrogation signal two or three times, the position of the transponder reader TRD is slightly changed so that the transmitting / receiving antenna 21 and the plurality of transponders TP-1 to TP-TP are changed.
Since the positional relationship between each of the transponders TP-1 to TP-n changes because the positional relationship between each of the transponders TP-1 to TP-n changes, the transponder TP- The transmission timings of the response signals from 1 to TP-n are also different, and all the response signals from the plurality of transponders TP-1 to TP-n can be received.

In this embodiment, each transponder T
Although the time constants (= R × C) of P-1 to TP-n were set completely at random as described above, if all were set to different values,
The probability that a plurality of response signals overlap can be reduced, and the time required until all the response signals are received can be reduced.
Furthermore, by setting the delay time based on the time constant in each of the transponders TP-1 to TP-n such that the time interval required for transmitting the response signal is increased, the probability that a plurality of response signals overlap can be further reduced. The time required until all the response signals are received can be further reduced.

As described above, according to the present embodiment, a plurality of transponders TP using electromagnetic waves having a frequency lower than the middle wave band, which is less attenuated than electromagnetic waves having a frequency higher than the short wave band, are used.
-1 to TP-n can be accessed almost simultaneously to obtain response signals from the transponders TP-1 to TP-n.

Further, at least at present, a transponder using an electromagnetic wave having a frequency equal to or lower than the medium wave band has a lower manufacturing cost than a transponder using an electromagnetic wave having a frequency equal to or higher than the short wave band. Can be.

In the transponder reader TRD, if the number of response signals that can be received is less than the number of access targets within about two or three seconds after transmitting the interrogation signal, an error display or the like is performed. You may do it.

Next, a second embodiment of the present invention will be described.

In the second embodiment, a transponder system similar to the first embodiment will be described as an example.

FIG. 7 is a block diagram showing an electric circuit of a transponder reader according to the second embodiment, and FIG. 8 is an external view showing a transponder reader according to the second embodiment. In these figures, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

The difference between the first embodiment and the second embodiment is that in the second embodiment, the configuration of the transponder reader TRD has two transmitting / receiving antennas 21a and 21b.
And an antenna switch 28, and an external output interface unit 29 for outputting the information of the received response signal to an external device.

That is, in FIG.
The switching operation is performed by a control signal from the central processing unit 23, and one of the two transmitting / receiving antennas 21a and 21b is connected to the transmitting / receiving unit 22. These transmitting / receiving antennas 21
As shown in FIG. 8, a and 21b are arranged at a predetermined distance from the front end of the housing 1A.

Further, the external output interface unit 29
As shown in FIG. 8, it has a connector 29a arranged at the bottom of the grip 1a, operates under the control of the central processing unit 23, and outputs data to an external device by, for example, RS232c.

Next, the operation of the transponder system using the transponder reader having the above configuration will be described.

Before using this system, the transponder T which accesses at almost the same time as in the first embodiment is used.
Set the number of P in the transponder reader TRD.

Thereafter, when the trigger switch 262 is turned on once with the tip of the transponder reader TRD facing the target package, the transmitting and receiving antennas 21a and 21b are alternately switched until the number of response signals that can be received reaches the number of access targets. Thus, the transmission of the interrogation signal and the reception of the response signal are performed.

The response signal information stored in the storage unit 24 can be output to an external device by the keyboard operation 261 of the operation unit 26.

Next, details of the above operation will be described with reference to the transponder reader operation flowchart of FIG.

In the transponder reader TRD, when the operation is started, the central processing unit 23 initializes the number of access targets, that is, the number N of transponders TP to be accessed almost simultaneously to "1" (SB1). Thereafter, when the setting change of the number N of access targets by the operator via the keyboard 261 is performed, the central processing unit 23 changes the number N of access targets (SB2).

Next, the central processing unit 23 determines whether or not the trigger switch 262 has been turned on (SB3). If the trigger switch 262 has not been turned on, whether or not a recording information output command has been input via the keyboard 261 Is determined (SB4).

If the result of this determination is that an output command has not been input, the flow shifts to the process of SB2, and if an output command has been input, all information of the response signal stored in the storage unit 24 is transferred to the interface unit. The data is output to the external device via the communication device 29 (SB5). Thereafter, the process proceeds to the process of SB2.

As a result of the determination in SB3, the trigger switch
When the switch 262 is turned on, a transmission command is output to the transmission / reception unit 22, and the transmission / reception unit 22 transmits the electromagnetic wave of the interrogation signal via the transmission / reception antenna 21 for 30 ms (SB6). After this,
The central processing unit 23 performs reception processing of the response signal (SB
7).

Along with this, the central processing unit 23 monitors whether the elapsed time from the transmission of the electromagnetic wave of the interrogation signal has reached the maximum reception time (SB8), and the elapsed time has reached the maximum reception time. Then, the number of different response signals that can be received is counted (SB9).

Next, the central processing unit 23 determines whether or not this count number is equal to the access target number N (SB)
10).

If the result of this determination is that the number of response signal reception completions does not reach the number of access targets N, the central processing unit 23
Outputs a switching control signal to the antenna switching unit 28, connects the transmitting / receiving antennas 21a and 21b different from those before to the transmitting / receiving unit 22 (SB11), and shifts to the process of SB2. Thereby, different transmitting / receiving antennas 21a,
The electromagnetic wave of the interrogation signal is transmitted again from 21b.

When the number of response signal reception completions reaches the number of access targets N, the central processing unit 23 transmits information such as identification information, a manufacturing factory, a manufacturing date and a product code from the received response signal. Extracted and displayed on the display unit 25 (SB1
2).

As described above, the transmission / reception antennas 21a and 21b are switched by the antenna switching unit 28,
By transmitting the electromagnetic wave of the interrogation signal by the method 2, the probability that response signals from a plurality of transponders overlap can be reduced.

That is, the transmitting and receiving antennas 21a and 21b are
In this case, the positional relationship between these transmitting / receiving antennas 21a and 21b and each of the plurality of transponders TP-1 to TP-n, the distance, the intervening shield, and the like differ for each transmitting / receiving antenna. For this reason, if the transmitting and receiving antennas from which the electromagnetic waves of the interrogation signal are transmitted are different, the timing at which the transponders TP-1 to TP-n receive the electromagnetic waves of the interrogation signal changes.
The transmission timing of the response signal from TP-n also differs. Thereby, the plurality of transponders TP-1 to TP
The response signal from -n can be separated and received.

As described above, the same effects as those of the first embodiment can be obtained by the second embodiment.

Although the transponder reader TRD has two transmitting / receiving antennas 21a and 21b in the second embodiment, three or more transmitting / receiving antennas may be used. For example, as shown in FIG. 10, a transponder reader TRD that includes four transmission / reception antennas 21a to 21d and switches these to perform transmission / reception may be configured. In this case, the antenna switch 28 is deleted as shown in FIG.
You may make it provide the transmission / reception parts 22a-22d in 1a-21d, respectively. Thus, the timing of radiating the electromagnetic wave of the interrogation signal from each of the transmission / reception antennas 21a to 21d can be changed in various ways, and the reception of the response signal can be completed in a shorter time.

Further, in the first and second embodiments, the transponder system for reading a plurality of pieces of product information packed in a package from the outside is configured. However, the present invention is not limited to these, and the present invention is not limited to this. It goes without saying that the present invention can be easily applied to information management of mounted tires.

In the first and second embodiments, 13
Transponder T using electromagnetic wave of frequency in 5 kHz band
Although a transponder system composed of P-1 to TP-n and a transponder reader TRD is configured,
It is not limited to the 35 KHz band.

Further, the configurations of the first and second embodiments are merely specific examples of the present invention, and the present invention is not limited to only these configurations.

[0121]

As described above, according to the transponder access method according to the first to sixth aspects of the present invention, a plurality of transponders using electromagnetic waves having a frequency equal to or lower than the middle-wave band are accessed almost simultaneously, and each transponder accesses the transponder. Can be obtained. As a result, a transponder using an electromagnetic wave having a frequency equal to or lower than the medium wave band, which is less attenuated than an electromagnetic wave having a frequency equal to or higher than the short wave band, can be used in various fields. Further, at least at present, transponders using electromagnetic waves of frequencies lower than the mid-wave band have lower manufacturing costs than transponders using electromagnetic waves of frequencies higher than the short-wave band. It greatly contributes to.

According to the transponder access method of the present invention, in addition to the above effects, the time from when the interrogation signal is received by two or more transponders to when the transmission of the response signal is started is obtained. Can also be separated and received as response signals from these transponders.

Further, according to the transponder access method of the third aspect, in addition to the above effects, the probability that the transmission timings of the response signals from two or more transponders coincide can be reduced. The time required to acquire response signals from all transponders to be accessed can be reduced.

According to the transponder access method of the fourth aspect, in addition to the above effects, when the transponder reader receives a response signal, part or all of two or more response signals are transmitted. Since the overlap probability can be reduced, the time required to acquire response signals from all transponders to be accessed almost simultaneously can be reduced.

Further, according to the transponder access method of the fifth aspect, in addition to the above-described effects, the number of response signals received from different transponders can be changed until the number of transponders to be accessed becomes the number of transponders. Since the transmission of the interrogation signal is repeated, response signals from all transponders to be accessed can be obtained without omission without performing a troublesome operation.

According to the access method of the transponder according to the sixth aspect, in addition to the above-mentioned effects, at least the frequency 135K currently commercialized is provided.
Since the transponder using the electromagnetic wave of Hz can be used, the use of the transponder can be widely spread.

Further, according to the transponder reader according to the seventh to thirteenth aspects, it is possible to access a plurality of transponders using electromagnetic waves having a frequency equal to or lower than the medium wave band almost simultaneously, and obtain a response signal from each transponder. As a result, a transponder using an electromagnetic wave having a frequency equal to or lower than the medium wave band, which is less attenuated than an electromagnetic wave having a frequency equal to or higher than the short wave band, can be used in various fields. Furthermore, at least at present, transponders using electromagnetic waves of frequencies below the medium waveband have lower manufacturing costs than transponders using electromagnetic waves of frequencies above the shortwave band. It greatly contributes to.

According to the transponder reader of the ninth aspect, in addition to the above effects, the transmission of the interrogation signal by the transmission / reception control unit is repeated until the number set by the access target number setting unit is reached. Accordingly, response signals from all transponders to be accessed can be obtained without omission. For this reason, for example, even when a transponder attached to each of a plurality of products packed in a package is accessed almost simultaneously from outside the package and information is obtained from all the transponders in the package, the Leakage can be prevented.

According to the transponder reader of the tenth aspect, in addition to the above effects, the information extracted by the information extracting means can be output to the external device by the information output means. Information extracted when used for product management in a package or the like can be effectively used in an external device.

According to the transponder reader of the present invention, in addition to the above effects, the information extracted by the information extracting means is accumulated and stored by the information storing means, so that the accumulated information is displayed. You can use it.

According to the transponder reader according to the twelfth aspect, in addition to the effects described above, the information stored in the information storage means can be output to the external device by the storage information output means. In addition, the stored extraction information can be effectively used in the external device.

According to the transponder reader according to the thirteenth aspect, in addition to the above-mentioned effects, since the transponder reader has a hand-held type casing, it can be carried and used by an operator, and the range of use can be expanded. Can be planned.

According to the transponder system of the present invention, a plurality of transponders using an electromagnetic wave of a frequency lower than a medium wave band which is less attenuated than an electromagnetic wave of a frequency higher than a short wave band are accessed almost simultaneously, and each transponder , A transponder using an electromagnetic wave having a frequency equal to or lower than the middle wave band can be used in various fields. Furthermore, at least at present, transponders using electromagnetic waves of frequencies below the medium waveband have lower manufacturing costs than transponders using electromagnetic waves of frequencies above the shortwave band. It greatly contributes to.

Further, according to the transponder system of the present invention, a plurality of transponders using electromagnetic waves having a frequency lower than a medium wave band, which is less attenuated than electromagnetic waves having a frequency higher than a short wave band, are accessed almost simultaneously, and each transponder , A transponder using an electromagnetic wave having a frequency equal to or lower than the middle wave band can be used in various fields. Furthermore, at least at present, transponders using electromagnetic waves of frequencies below the medium waveband have lower manufacturing costs than transponders using electromagnetic waves of frequencies above the shortwave band. It greatly contributes to.

According to the transponder system of the sixteenth aspect, in addition to the above-described effects, the delay time of each transponder to be accessed almost simultaneously is set to a different value for each transponder. Can be reduced, so that it is possible to reduce the time required to acquire response signals from all transponders to be accessed almost simultaneously.

According to the transponder system of the seventeenth aspect, in addition to the above effects, the transmission timing of the response signal in each transponder can be very easily changed by changing the time constant of the power storage in the power storage means of the transponder. They can be different from each other.

According to the transponder system of the eighteenth aspect, in addition to the above effects, since the response signals transmitted from the transponders do not theoretically overlap each other, all of the plurality of response signals can be used. The time required for acquisition can be shortened.

According to the transponder system of the nineteenth aspect, in addition to the above-mentioned effects, it is possible to utilize at least a transponder that uses an electromagnetic wave having a frequency of 135 KHz which is currently commercialized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a transponder system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an electric circuit of the transponder according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing an electric circuit of the transponder reader according to the first embodiment of the present invention.

FIG. 4 is an external view showing a transponder reader according to the first embodiment of the present invention.

FIG. 5 is an operation flowchart of the transponder reader according to the first embodiment of the present invention.

FIG. 6 is a timing chart of a transponder reader and a transponder according to the first embodiment of the present invention;

FIG. 7 is a block diagram showing an electric circuit of a transponder reader according to a second embodiment of the present invention.

FIG. 8 is an external view showing a transponder reader according to a second embodiment of the present invention.

FIG. 9 is an operation flowchart of a transponder reader according to the second embodiment of the present invention.

FIG. 10 is an external view showing another configuration example of the transponder reader according to the present invention.

FIG. 11 is a block diagram showing another configuration example of the transponder reader according to the present invention.

[Explanation of symbols]

TP (TP-1 to TP-n): transponder, TRD: transponder reader, 10: transponder, 11:
Antenna wire, 12 rectifier circuit, 121 diode, 122 ...
Resistor, 123… Capacitor, 13… Central processing unit, 14…
Storage unit, 15: transmission unit, 16: changeover switch, 2
0,20A ... Transponder reader, 21,21a ~
21d: transmission / reception antenna, 22, 22a to 22d: transmission / reception unit, 23: central processing unit, 24: storage unit, 25: display unit, 26: operation unit, 261: keyboard, 262: trigger switch, 27: power supply unit, 28 ... Antenna switch, 29 ... External output interface unit, 29a ... Connector.

Claims (19)

[Claims] An interrogation signal is transmitted from a transponder reader to a plurality of transponders that transmit a response signal when an electromagnetic wave serving as an interrogation signal is received using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band. A method of accessing a transponder that receives a response signal from a transponder, wherein the time from receiving an interrogation signal in each of the plurality of transponders to starting transmission of a response signal is randomly determined within a predetermined distributed time. After setting, the transponder reader transmits the interrogation signal once and then receives the response signal while maintaining the reception state at least during the time obtained by adding the dispersion time and the time required for one response signal transmission. A method for accessing a transponder, comprising: 2. The transponder reader further comprises two or more transmitting and receiving antennas arranged at different positions from each other, and transmitting and receiving the interrogation signal and receiving the response signal by sequentially switching the transmitting and receiving antennas. Claim 1
Access method of the described transponder. 3. The transponder access method according to claim 1, wherein a time from when the transponder receives the interrogation signal to when transmission of the response signal is started is set to a different value for each transponder. 4. The method according to claim 1, wherein the plurality of transponders are configured such that a time period from when the interrogation signal is received to when the transmission of the response signal is started is different from each other by at least a natural number times the response signal transmission time. Claim 3
Access method of the described transponder. 5. The transponder reader sets the number of transponders to be accessed, and the transponder reader repeats transmission of an interrogation signal at the transmission timing until response signals can be received from all transponders to be accessed. 2. The access method for a transponder according to claim 1, wherein: 6. The frequency of the electromagnetic wave is 135 KHz.
2. The method according to claim 1, wherein a band is used. 7. An interrogation signal is transmitted to a plurality of transponders that transmit a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band, and receive a response signal. In the transponder reader, two or more transmitting / receiving antennas arranged at different positions from each other, and transmitting an interrogation signal electromagnetic wave for a predetermined transmission time via the transmitting / receiving antenna when receiving a transmission command, and transmitting the interrogation signal A transmission / reception unit that maintains a reception state and outputs a received response signal as an electric signal when not receiving, and an antenna switching unit that sequentially switches connection of the transmission / reception unit at predetermined intervals to the plurality of transmission / reception antennas. Transmission / reception control means for transmitting the transmission command to the transmission / reception unit at every predetermined time interval; Enter a plurality of response signals,
A transponder reader comprising: information extracting means for extracting predetermined information included in each of the plurality of response signals; and display means for displaying information extracted by the information extracting means. 8. An interrogator transmits an interrogation signal and receives a response signal to a plurality of transponders that transmit a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band. In the transponder reader, two or more transmitting / receiving antennas arranged at different positions from each other, and provided for each of the transmitting / receiving antennas, and transmitting an electromagnetic wave of an interrogation signal for a predetermined transmission time when receiving a transmission command. And a plurality of transmitting and receiving units that maintain the receiving state and output the received response signal as an electric signal except when transmitting an interrogation signal, and the plurality of transmitting and receiving units are sequentially arranged at predetermined time intervals. Transmission / reception control means for transmitting the transmission command; and inputting a plurality of response signals output from the plurality of transmission / reception units, each of the plurality of response signals Transponder reader, characterized in that it includes an information extracting means for extracting predetermined information, and display means for displaying the information extracted by the information extraction means contained in the. 9. An access object number setting means for setting the number of transponders to be accessed substantially simultaneously; extracting identification information unique to each transponder from said response signal; 9. The transponder reader according to claim 7, further comprising a transmission repetition unit that repeats transmission to the transmission / reception control unit until the number reaches the number set by the target number setting unit. 10. The transponder reader according to claim 7, further comprising information output means for outputting the information extracted by said information extraction means to an external device. 11. The transponder reader according to claim 7, further comprising information storage means for accumulating and storing information extracted by said information extraction means. 12. The transponder reader according to claim 11, further comprising storage information output means for outputting information stored in said information storage means to an external device. 13. The transponder reader according to claim 7, further comprising a hand-held case, wherein the transmitting / receiving antenna is mounted on the case. 14. A plurality of transponders for transmitting a response signal when an electromagnetic wave serving as an interrogation signal is received using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band, and a response signal for transmitting an interrogation signal to these transponders. A transponder reader comprising: a transponder reader, the transponder reader transmits a transmission / reception antenna and an electromagnetic wave of an interrogation signal via the transmission / reception antenna for a predetermined transmission time when receiving a transmission command; A transmission / reception unit that maintains a reception state and outputs a received response signal as an electric signal except when transmitting an interrogation signal, a transmission / reception control unit that sends the transmission command to the transmission / reception unit, and a transponder that accesses substantially simultaneously. Means for setting the number of access targets for setting the number of Transmission repetition means for extracting identification information unique to the responder and repeating transmission to the transmission / reception control means until the number of the extracted different identification information reaches the number set by the access target number setting means. Inputting a plurality of response signals output from the transmitting and receiving unit,
Information extracting means for extracting predetermined information contained in each of the plurality of response signals, and display means for displaying the information extracted by the information extracting means, wherein the transponder receives the electromagnetic wave of the interrogation signal A response delay unit for starting transmission of a response signal after a predetermined delay time has elapsed, wherein a delay time of the response delay unit of each transponder is set to a random value within a predetermined time period. Transponder system. 15. A plurality of transponders for transmitting a response signal when an electromagnetic wave serving as an interrogation signal is received by using an electromagnetic wave having a predetermined frequency equal to or lower than a medium wave band, and a response signal for transmitting an interrogation signal to these transponders. A transponder system comprising: a transponder reader for receiving the transponder; wherein the transponder reader is the transponder reader.
And the transponder has a response delay unit that starts transmitting a response signal after a predetermined delay time has elapsed after receiving the electromagnetic wave of the interrogation signal. A transponder system, wherein a delay time of the response delay means is set to a random value within a predetermined time. 16. The transponder system according to claim 14, wherein a delay time of said response delay means is set to a different value for each transponder. 17. A power storage means for storing the electromagnetic wave energy of the interrogation signal with a predetermined time constant, and a response transmission for transmitting a response signal when the power storage energy of the power storage means reaches a predetermined value. The transponder system according to claim 14, wherein the delay time is set by the time constant. 18. The delay time of each transponder,
15. The method according to claim 14, wherein the difference is set to be at least a natural number times the response signal transmission time.
6. The transponder system according to claim 5. 19. The transponder system according to claim 14, wherein the interrogation signal and the response signal have a frequency of about 135 KHz.