JPH09139692A - Responder for vehicular identification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power and to hold the life in a battery to be long by generating a start signal starting circuits in a responder body based on a generated burst signal. SOLUTION: A start signal generation part 12 generates the start signal starting the respective circuits (supplying power) in the body of a responder 2 based on the burst signal generated from an SAW fixed code matched filter part 11 and gives it to a power control part 4. Namely, a PN code generation part 13 generates a PN code to which the target responder applies, a composite modulation part 14 executes BPSK modulation and a micro wave is generated toward the responder 2 when communication with the specified responder 2 is desired in an interrogator 1. The pertinent responder 2 receives the BPSK modulation wave and generates the burst signal in the SAW fixed code matched filter part 11. Then, the burst signal is generated based on the start signal and the communication operation of the responder 2 is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives a radio wave emitted from an interrogator having a data transmitting / receiving function, modulates it according to unique information and reflects it to the interrogator to transmit information, or transmits from an interrogator. The present invention relates to a transponder for a mobile body identification device having a function of receiving a radio wave modulated according to the information of (1) and demodulating to obtain information, and particularly for power saving, improvement of security, and improvement of mass productivity. The present invention relates to a transponder for a moving body identifying device.

[0002]

2. Description of the Related Art Conventionally, a moving body identifying apparatus for identifying a moving body has been widely known. And, especially under the Radio Law, radio waves (microwave) are used for communication between the interrogator and the responder.
There are also provisions regarding what is used.

This type of moving body identifying apparatus is generally composed of an interrogator installed in a fixed station and a responder provided in the moving body. That is, for example, a vehicle, an article to be transported, a person, or the like is provided with a transponder, a predetermined microwave emitted from the interrogator is received by the transponder, and specified by the information stored in the transponder. The received microwave is modulated by the information signal subjected to the process (1), and then the modulated microwave is reflected and returned to the interrogator, thereby transmitting information in a contactless manner. Is possible.

It is also possible to write information in the responder by modulating and transmitting the information on the interrogator side to the microwave emitted from the interrogator. By the way, the moving body identifying apparatus as described above is a wireless card such as a toll collection system for toll motorways, a ticket automatic ticketing system for passenger railways, etc., in addition to a physical distribution management system in which a responder is attached to an article for management. Has been proposed for use.

Therefore, a long-life type transponder is desired, and for this purpose, it is necessary to reduce the consumption of the battery inside the transponder. Therefore, the transponder has a function of detecting a general communicable area (distance) by itself.

That is, only when the interrogator and the responder are communicating, the control unit composed of the CPU and all other circuits operate, and at the time other than the communication, only the communicable area (distance) detecting unit is operated. It is designed to operate with low power consumption. Further, such a function reduces the consumption of the battery inside the transponder.

On the other hand, as a method for detecting the communicable area (distance), the microwave emitted from the interrogator is detected and the level is monitored and controlled. In addition, in order to prevent malfunction due to external noise and further improve accuracy, the microwave emitted from the interrogator is subjected to modulation processing with a specific modulation signal, the responder detects this microwave, and the modulation signal is further filtered with a filter. There is also a method of controlling by extracting only the component and monitoring the level of this modulation signal component.

By the way, in the moving body identifying apparatus, the responder receives a predetermined microwave emitted from the interrogator, modulates the microwave with the information signal in the responder, and reflects the microwave to inform the interrogator. Since it is a mechanism for transmitting, the interrogator and the responder are instantaneously a one-to-one communication system.

Therefore, when there is only one responder in the communicable area of the interrogator, there is no problem, but when there are a plurality of responders, all the responses are possible only by this communicable area detecting function. The vessel responds and data cannot be read.

Therefore, a moving body identifying apparatus has been proposed which has a function of selecting a responder in addition to the function of detecting a communicable area (distance). That is, as one of the methods, an individual identification code, address information, etc. are given to the transponder in advance. Then, the microwave from the interrogator is modulated with an information signal to which command information and further identification information and address information are added,
Fire at the transponder. On the other hand, in the transponder, this information is reproduced, and the control unit composed of the internal CPU determines whether the interrogator is the identification code or address of the desired transponder, and only the corresponding transponder becomes the interrogator. A response signal is issued to the device. The other transponders are in the power saving mode again.

On the other hand, in addition to the above-described method in which individual identification codes, address information, etc. are given to the transponder in advance, a data pattern generator for periodically generating specific data or data pattern is provided inside the transponder. A method has also been proposed in which communication is started when it coincides with the communication start request signal from the interrogator.

The following is a description of the moving body identifying apparatus described above.
A more specific description will be given with reference to the drawings. FIG. 7 is a block diagram showing a schematic configuration example of a conventional mobile body identification device.

That is, as shown in FIG. 7, the moving body identifying apparatus comprises an interrogator 1 and a responder 2. The responder 2 receives and detects a predetermined microwave emitted from the interrogator 1, and activates the responder 2 itself. When transmitting the individual information inside the transponder 2 to the interrogator 1, the transponder receives the unmodulated microwave emitted from the interrogator 1, and the received radio wave is stored in the transponder 2. Information is transmitted by modulating it according to individual information and reflecting it again to the interrogator 1.

When transmitting information from the interrogator 1 to the responder 2, the microwave emitted from the interrogator 1 is
The information is modulated according to the information and emitted as a modulated wave.
Then, the transponder 2 which receives this demodulates, reproduces and stores the information.

As described above, the transponder 2 does not have a microwave oscillator which serves as a carrier for information transmission, and therefore is very power-saving. On the other hand, a communication area (distance) detection function including the microwave detection unit 3 and the power supply control unit 4 is provided in order to further enhance the power saving property of the transponder, which is a feature of the mobile body identification device.

That is, during communication standby, only the microwave detection unit 3 and the power supply control unit 4 operate with low power consumption, and when the transponder 2 enters the communicable area of the interrogator 1, the interrogator 1 The microwave detection unit 3 detects the level of the microwave from and when it reaches a certain level, it sends a signal to the power supply control unit 4.

Then, the power supply control unit 4 supplies power from the power supply unit 5 to the control unit 6 including the CPU, the memory unit 7, the detection / amplification / demodulation unit 10, and the modulation unit 17 by this signal. Then, the transponder 2 is brought into a communication-enabled state and starts communication with the interrogator 1. CP at the end of communication
The control unit 6 composed of U sends a signal of communication completion to the power supply control unit 4, and the entire responder 2 again shifts to the power saving mode.

However, with such a function alone, when a plurality of transponders 2 enter the communicable area of the interrogator 1, all the transponders react and the normal communication operation is not performed. .

Therefore, in general, for each responder 2, the responder 2 is provided in the ROM area of the control unit 6 or the memory unit 7.
Store different individual codes, addresses, etc. for each
The inquiry signal from the interrogator 1 is transmitted by including the individual code or address of the responder to be communicated. And
Each responder 2 receiving this signal reproduces the information of the interrogator 1 by the detection / amplification / demodulation unit 10 and sends it to the control unit 6,
Due to the function of the control unit 6, only the responder 2 that matches its own individual code, address, etc. returns a response signal to the interrogator 1. The other transponders 2 that do not match immediately shift to the power saving mode. In this way, communication is performed between the interrogator 1 and the specific responder 2, which is due to the software control of the controller 6 of the responder 2.

In some cases, the same function as that described above may be implemented by hardware as shown in the block diagram of FIG. That is, as shown in FIG. 8, the data pattern generator 8 generates an individual code unique to each responder 2,
Similar to the above-mentioned method, the inquiry signal from the interrogator 1 is transmitted by including the individual code.
When the condition determination unit 9 matches its own individual code pattern with the code pattern from the interrogator 1, a signal is generated and sent to the control unit 6. Then, the control unit 6 sends back a response signal to the interrogator 1 based on this signal to start communication, but if there is no signal sent from the condition judging unit 9, the entire responder 2 is omitted. Control to enter power mode.

However, the interrogator 1 is used in these mobile body identification devices having the function of detecting the communicable area (distance) of the transponder 2 and the function of selecting a specific transponder 2 from the plurality of transponders 2. After detecting the level of the microwave emitted from the control unit 6, the control unit 6 and the data pattern generation unit 8, the condition determination unit 9, the detection / amplification / The operation of the demodulation unit 10 and the like is necessary. Therefore, the transponder 2 not requested to communicate consumes unnecessary power during this determination period.

In addition, as a method of giving individual identification codes, address information and the like to the responder 2 in advance, a method of writing in the memory section 7 of the responder 2 after the responder 2 is manufactured is easy to be forged, especially in the financial system. Application lacks security.

Further, as a method of giving individual identification codes, address information and the like to the transponder 2 in advance, a method of writing it in the ROM area of the control unit 6 composed of a CPU in advance at the time of manufacturing the transponder 2 has a high security. In consideration of the above, since it is necessary to manufacture the ROM area of the control unit 6 or the hardware configuration while changing the data to be written in each responder 2, mass productivity may be reduced and cost may be increased.

[0024]

As described above, the transponder of the conventional moving body identifying apparatus has a problem in terms of power saving, security, and mass productivity. A first object of the present invention is that even if a plurality of transponders exist within the communicable area of an interrogator, information can be surely communicated with only a specific transponder without interference, and wasteful. Another object of the present invention is to provide a transponder for a moving object identifying device, which can save power consumption by saving unnecessary power consumption and can keep the internal battery life longer.

A second object of the present invention is to reliably communicate information with only a specific responder without causing interference even if a plurality of responders exist within the communicable area of the interrogator. Another object of the present invention is to provide a transponder for a mobile body identification device, which is capable of improving security. Further, a third object of the present invention is to provide a transponder for a moving object identifying device, which can be mass-produced and can be manufactured more generally.

[0026]

First, in order to achieve the first object, the invention according to claim 1 is provided in a moving body such as a vehicle or an article to be conveyed, and is installed in a fixed station. Pseudo noise from the interrogator in the transponder for mobile identification device that receives the radio wave emitted from the interrogator that has the data transmission / reception function, adds the individual information to the radio wave, and transmits it to the interrogator again SAW fixed code matched filter means for receiving a radio wave binary-phase-modulated by a (PN) code and generating a burst signal when the radio wave is matched with a specific code recorded in advance on a surface acoustic wave element (SAW element). , A start signal generating means for generating a start signal for starting a circuit inside the transponder body based on the burst signal generated from the SAW fixed code matched filter means. Made.

In order to achieve the second object,
In the invention corresponding to claim 2, a radio wave emitted from an interrogator provided in a moving body such as a vehicle or an article to be transported and having a data transmission / reception function installed in a fixed station is received, and the radio wave receives individual information. In the transponder for a mobile body identification device, which is added with and transmitted again to the interrogator, a radio wave binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received, and this is transmitted in advance by the surface acoustic wave element. (SAW element)
The SAW fixed code matched filter means for generating a burst signal when it matches the specific code recorded in the above, and the presence / absence of the burst signal generated from the SAW fixed code matched filter means are detected, and the burst signal may be present. When it is detected, it is provided with an information judging means for giving information to the control unit composed of the CPU inside the transponder main body to continue the execution of the processing.

Further, in order to achieve the above first and second objects, in the invention corresponding to claim 3, data transmission / reception installed in a fixed station, which is provided in a moving body such as a vehicle or an article to be transported. Pseudo noise (PN) from an interrogator in a transponder for a mobile body identification device, which receives an electric wave emitted from an interrogator having a function, adds individual information to the electric wave, and transmits again to the interrogator SAW fixed code matched filter means for receiving a radio wave binary-phase-modulated by a code and generating a burst signal when the received radio wave coincides with a specific code recorded in advance on a surface acoustic wave element (SAW element), and SAW fixed Based on the burst signal generated from the code matched filter means, a start signal generating means for generating a start signal for activating a circuit inside the responder body, and a SAW fixed Code to detect the presence or absence of the generated burst signal from the matched filter means, the internal response body when the said burst signal is present is detected C
An information judging means for giving information to the effect that the processing execution is continued to the control unit composed of PU.

On the other hand, in order to achieve the above-mentioned second and third objects, in the invention corresponding to claim 4, the above-mentioned claim 1 is adopted.
In the transponder for a moving body identifying device according to any one of claims 1 to 3, the input electrode and the output electrode provided on the surface acoustic wave element of the SAW fixed code matched filter means are heated by a laser beam or the like. The beam is removed (trimmed) so that a specific code is recorded and weighted as individual information of the transponder body.

In order to achieve the above second object,
According to a fifth aspect of the present invention, in the transponder for a mobile body identification device according to any one of the first to fourth aspects of the invention, the surface acoustic wave element of the SAW fixed code matched filter means is a transponder. Buried near the surface of the main body,
And, on the surface of the surface acoustic wave element, a separation layer having a window forming a void, a concealing layer for concealing recorded information recorded in the surface acoustic wave element and transmitting infrared rays, and transparent The protective layers are sequentially laminated.

Therefore, first, in the moving body identification device responder of the invention according to claim 1, the radio wave which is binary phase modulated by the pseudo noise (PN) code from the interrogator is received, and the elastic surface is preliminarily set. A burst signal generated when a specific code recorded in the wave element (SAW element) is activated to activate the internal circuit of the transponder body, and thus multiple transponders exist within the communicable area of the interrogator. In this case, the information can be surely communicated only with the responder of the communication contrast, and regarding the other responders, whether or not the responder requires the communication as in the conventional method described above. There is no need for a judgment operation, and there is no power consumption of the control unit and the communication circuit unit during this period, so that useless power consumption is eliminated and power saving can be achieved. This allows
The battery life inside the transponder can be maintained longer.

Further, in the transponder for a moving body identifying apparatus of the invention according to claim 2, pseudo noise (P
N) Receiving a burst signal generated when a radio wave that has been binary-phase-modulated by a code is received and it matches with a specific code recorded in advance on a surface acoustic wave element (SAW element) By giving information to the effect that the processing execution is continued to the control unit composed of the CPU inside the main body of the device, it is possible to correspond to the system such as the above-mentioned conventional system, and further, the respective conventional responses described above. Since the responder can be selected by the PN code in addition to the information such as the individual code and address of the device, the security can be improved as compared with the conventional device. Also,
Differentiating and ranking transponders broadens applications.

Further, in the transponder for a mobile body identification device of the invention according to claim 3, the radio wave which is binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received,
A burst signal generated when a specific code recorded in advance on the surface acoustic wave element (SAW element) matches the activation of the internal circuit of the transponder body, thus enabling multiple responses within the communicable area of the interrogator. Even if a responder is present, information can be reliably communicated only with the responder to which communication is to be performed. The operation of determining whether or not there is no need, and since the control unit and the communication circuit unit have no power consumption during this period, there is no unnecessary power consumption, and power saving can be achieved. As a result, the battery life inside the transponder can be kept longer.

Also, it occurs when a radio wave binary-phase-modulated by a pseudo noise (PN) code is received from an interrogator and coincides with a specific code recorded in advance on a surface acoustic wave element (SAW element). When the presence of the burst signal is detected, the control unit composed of the CPU inside the transponder body is provided with the information indicating that the processing execution is continued, thereby supporting the conventional system described above. In addition, the responder can be selected by the PN code in addition to the information such as the individual code and address of each responder of the related art described above, so that the security can be improved as compared with the conventional device. .

On the other hand, in the transponder for a moving body identifying apparatus of the invention according to claim 4, the input electrode and the output electrode provided on the surface acoustic wave element of the SAW fixed code matched filter means are provided with an external laser beam. It is impossible to rewrite by removing (trimming) with a heat beam such as etc. Even if it is rewritten, the transponder itself cannot be used, and it is possible to reliably prevent fraud and further improve security. Can be improved.

Further, unlike the method of writing the identification code in the ROM area as in the above-mentioned conventional method, mass productivity is improved, and more versatile manufacturing is possible. Furthermore, by recording a specific code and weighting it as individual information of the transponder body, transponders can be differentiated and ranked, so that applications can be expanded.

Further, in the transponder for a moving body identifying apparatus according to the present invention, the separation layer is formed on the surface of the surface acoustic wave element of the SAW fixed code matched filter means embedded near the surface of the transponder body. Further, since the specific code pattern in the SAW fixed code matched filter means cannot be visually recognized by printing the hiding layer by sequentially laminating the hiding layer and the hiding layer, the security is further improved. It is possible to improve the property.

[0038]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a schematic block diagram showing a configuration example of a moving body identifying apparatus to which a transponder according to the present embodiment is applied, and the same elements as those in FIGS. 7 and 8 are designated by the same reference numerals. Is shown.

In FIG. 1, the mobile unit identification device comprises an interrogator 1 installed in a fixed station and a transponder 2 attached to or carried by the mobile unit. The wave Fc is received by the transponder 2, and the received microwave Fc is modulated by the information signal that has been subjected to specific processing by the individual information stored in the transponder 2,
After that, a reflected wave Fr is returned from the responder 2 to the interrogator 1.

Further, the interrogator 1 has a pseudo noise (hereinafter, PN
(Hereinafter referred to as a code generator) 13, a composite modulator 14, a microwave oscillator 15, a controller 16, and a reception detector 18.
And a demodulation unit 19.

Further, the responder 2 is similar to the responder 2 in FIG. 7 except that the SAW fixed code matched filter unit 11,
And a start signal generator 12 is added. Here, the PN code generator 13 is for generating a PN code.

The microwave oscillating section 15 oscillates microwaves. Furthermore, the composite modulator 14
Applies ASK modulation when transmitting information, and when selecting a specific transponder 2, the PN code from the PN code generating section 13 causes the microwave from the microwave oscillating section 15 to have a binary phase (BPSK). (Bi-Phase Shift Keying
)) Modulation is applied.

On the other hand, the reception detection section 18 receives and detects the response information returned from the transponder 2. Further, the demodulation unit 19 demodulates the detection signal from the reception detection unit 18 and gives it to the control unit 16.

Further, the control section 16 is connected to an external interface and controls the PN code generation section 13, the composite modulation section 14, and the reception detection section 18.
On the other hand, the SAW fixed code matched filter unit 11 uses the PN code from the interrogator 1 to generate a binary phase (hereinafter, BPSK).
A modulated radio wave (called Bi-Phase Shift Keying) is received, and this is a surface acoustic wave (hereinafter SAW).
A burst signal is generated when a specific code recorded in the element is matched.

The activation signal generator 12 activates each circuit inside the transponder 2 based on the burst signal generated from the SAW fixed code matched filter unit 11 (in other words, supplies power). Generate a start signal,
It is provided to the power supply control unit 4.

The SAW fixed code matched filter unit 11 in the transponder 2 is buried relatively near the surface of the transponder 2 main body, and the input electrode and the output electrode provided in the SAW element are connected to the external laser beam or the like. By removing (trimming) with the heat beam, a specific code is recorded and weighted as individual information of the transponder 2 main body.

The SAW matched filter section 11, the activation signal generating section 12, the microwave detecting section 3 and the power supply controlling section 4 in the transponder 2 are configured to operate with low power consumption.

As described above, the mobile unit identifying apparatus to which the responder 2 of the present embodiment is applied, when the interrogator 1 wants to communicate with a specific responder 2, the PN code generator 13 is first.
Then, the target transponder generates a corresponding PN code, the composite modulator 14 performs BPSK modulation, and the microwave is emitted toward the transponder 2. The corresponding transponder 2 is this B
The PSK modulated wave is received and the SAW fixed code matched filter unit 11 generates a burst signal. And
Generate a start signal based on this burst signal, and
The communication operation of is started.

Next, the operation of the moving body identifying apparatus to which the transponder 2 of the present embodiment configured as described above is applied will be described. In FIG. 1, the microwave oscillating unit 15 of the interrogator 1 oscillates a microwave of a predetermined wavelength to transmit information of the interrogator 1, and an ASK modulation system, and when a specific transponder 2 is selected, a BPSK modulation system. Are sent to the composite type modulation unit 14 capable of performing both modulations.

First, when it is desired to communicate with a specific transponder 2, the control unit 16 in the interrogator 1 communicates with the transponder 2 to communicate.
A signal is sent to the PN code generation unit 13 so as to generate the same PN code as the specific code of the SAW fixed code matched filter unit 11. Then, in the PN code generator 13,
The PN code as instructed is generated and sent to the composite modulation unit 14, and the responder 2 is used as the microwave Fc of the BPSK modulated wave.
Fire towards.

On the other hand, in the responder 2, this microwave Fc
Is received by the transmission / reception antenna 24, and the microwave detection unit 3 detects that the microwave has a predetermined level,
A signal is given to the power supply controller 4.

Further, in the SAW fixed code matched filter unit 11, a burst signal is generated at the moment when the microwave Fc, which is a BPSK modulated wave, and the specific code match. Therefore, based on this, the activation signal generation unit 12 activates the burst signal. A signal is generated and sent to the power supply control unit 4.

Then, the power supply control section 4 operates so as to supply power to other circuits when receiving both signals from the microwave detection section 3 and the activation signal generation section 12.
Then, the responder 2 starts communication with the interrogator 1.

That is, the control unit 6 in the responder 2 is
When the power is turned on and the power is turned on, first, the response information is returned to the interrogator 1, and the response information is transmitted to the modulator 1.
7, the unmodulated microwave Fc from the interrogator 1 is modulated and returned to the interrogator 1 as a reflected wave Fr.

On the other hand, the interrogator 1 receives the reflected wave Fr and obtains a detection signal by the reception detection section 18 which homodyne-detects a part of the energy of the microwave oscillation section 15 of the interrogator 1.
The demodulation unit 19 reproduces response information from the transponder 2 side from the detected signal. Then, the control unit 16 makes a determination, and the communication is further continued.

Next, when the information is sent from the interrogator 1 to the responder 2, the transmission information from the controller 16 is changed to the composite modulator 1.
4, and the composite modulator 14 performs ASK modulation, and emits it as a microwave Fc of the ASK modulated wave toward the reactor 2.

On the other hand, in the responder 2, this microwave Fc
Is received by the transmission / reception antenna 24, and the detection / amplification / demodulation unit 10 reproduces the transmission information from the interrogator 1 and sends it to the control unit 6. Then, after the judgment is made by the control unit 6, it is stored in the memory unit 7.

In the above operation, the microwave detector 3 in the transponder 2, the power supply controller 4, and the SAW.
Fixed code matched filter unit 11, start signal generation unit 1
2 is formed with a circuit configuration of extremely low power consumption, and is in an extremely power saving mode while the transponder 2 is on standby for communication.
Then, only when the specific code of the SAW fixed code matched filter unit 11 matches, the power supply to the other circuits is turned on and unnecessary power consumption is eliminated.

Next, the SAW fixed code matched filter unit 11 will be described in detail. First, the general principle of a SAW matched filter using a SAW element will be described.

The SAW device including the SAW element utilizes a surface acoustic wave transmitted along the surface of an elastic body, and is used as a delay line, a filter, a resonator, an oscillator, or the like.

The propagation velocity of the surface acoustic wave propagating through this SAW device is generally extremely slow, about 1 / 100,000 of the electromagnetic wave, and since the surface acoustic wave propagates on the surface of the SAW element at a depth of about 1 wavelength, The SAW device can be driven and detected at any position, and the SAW element can be reduced in size and weight, and the surface acoustic wave frequency is 10
It can be used in the range of MHz to several GHz.

Due to these characteristics, a highly accurate transversal filter is possible, and a typical practical example of a SAW device is a TV SAWIF filter.
This SAW matched filter has a comb-shaped metal electrode formed on a piezoelectric substrate made of crystal, lithium niobate, lithium tantalate, or the like by photolithography, vapor deposition, sputtering, or the like. For SA
A SAW matched filter can be considered as an extension of the WIF filter.

The SAW matched filter is a special example of the transversal filter, and its principle diagram can be constructed by an equivalent circuit as shown in FIG. That is,
In FIG. 2, D _n-1 (n = 1, 2, ..., N) represents a delay circuit, and W _n (n = 1, 2, ..., N) represents a weighting circuit.

Further, as one example thereof is shown in the perspective view of FIG. 3, the SAW element 21 includes a dielectric substrate for propagating a surface acoustic wave, and a transducer (transducer) for converting energy between an electric signal and an elastic wave. Composed of.

The transducer is composed of an input electrode 22 and an output electrode 23 formed in a comb pattern. The input electrode 22 operates as a transducer for converting an electric signal into a surface acoustic wave, and the output electrode 23 propagates. It operates as a transducer that converts surface acoustic waves into electric signals.

In this case, the input electrode 22 operates as a converter for converting a wide band electric signal into a surface acoustic wave, and when a high frequency signal is input to the input electrode 22, an elastic wave is generated in the left and right directions of the surface of the piezoelectric body. .

Then, in the present embodiment, as shown in FIG. 3, the input electrode 22 is formed into a comb-shaped electrode composed of two segments, the output electrode 23 is formed into a comb-shaped electrode composed of four segments, and the output electrode 23 is formed. 2 corresponds to the delay circuit D _n-1 shown in FIG. 2, and the crossing width of the adjacent comb-shaped electrodes is the weighting circuit W _n shown in FIG.
Corresponding to

FIG. 3 is an equivalent circuit diagram showing an example of a SAW matched filter for signal detection of a PN code modulated wave that has been BPSK modulated. In FIG. 3, 22 is an input electrode, 2
Reference numeral 3 denotes an output electrode, input electrode 22 is a wide band transducer that faithfully SAW converts an input signal, and output electrode 23 is an output transducer in which an electrode pattern is formed so as to correspond to a phase pattern of a target signal. .

In the transponder 2 provided with such a SAW element 21, the target PN transmitted from the interrogator 1 is transmitted.
When the microwave Fc BPSK-modulated by the code is received by the transmission / reception antenna 24, it is input to the input electrode 22 as an electric signal and converted into a surface acoustic wave by the input electrode 22.

This surface acoustic wave propagates on the delay circuit formed by the series of comb-shaped electrode pairs of the output electrode 23, and the input surface acoustic wave signal pattern and the weighting pattern of the output electrode 23 are output to the output electrode 23. When match
Peak output is obtained.

That is, the activation signal generator 12 in the responder 2 detects the peak output signal to confirm the agreement with the target PN code transmitted from the interrogator 1, and the power controller 4 and An activation signal can be given to the control unit 6.

Next, the principle of laser irradiation recording, which is a method of writing a weighting pattern, which is a specific code, in the transponder 2 having the SAW element 21 by laser irradiation will be briefly described.

The oscillation wavelength of the laser used for recording is 800 nm. FIG. 4 is a vertical cross-sectional view showing an example of a process of forming a specific code pattern on the output electrode 23 of the SAW element 21 with a laser beam.

That is, as shown in FIG. 4, the SAW element 21 is embedded near the surface of the transponder 2. Then, on the surface of the SAW element 21, a separation layer 28 having a window portion that forms a void portion, and for the purpose of hiding recorded information recorded in the SAW element 21, printing that further transmits infrared rays is possible. Concealing layer 29 and transparent protective layer 30
Are sequentially laminated.

The metal base material 25, the dielectric layer 26, and the metal thin film layer 27 are also used as a base material for a transmission line with other circuit parts, and a strip line (transmission line) is formed on the metal thin film layer 27. It is realized by drawing.

Now, when recording a specific code by laser irradiation, first, an unnecessary portion of the output side comb-shaped electrode 23 of the SAW element 21 provided in the transponder 2, that is, a cross mark in the plan view of FIG. As shown in FIG. 4, the trimming portion 31, which is one end of the comb shape, is irradiated with the focused laser beam 32 through the window 28a, and the irradiation heat thereof melts the trimming portion 31 of the comb-shaped metal electrode. , The metal thin film layer 27 is perforated.

In this case, the molten metal becomes a state in which small metal particles called ball-up are aggregated due to the surface tension. In the output electrode 23, as shown in FIG. 5, the unnecessary comb-shaped trimming portion 31 is melted and cut by the laser beam 32 based on each weighting pattern, so that the responder 2 can be identified as shown in FIG. A weighting pattern corresponding to the code is formed. Thereby, SA
It is recorded as data of the W fixed code matched filter unit 11.

Then, in such a transponder 2,
The microwave Fc BPSK-modulated by the target PN code transmitted from the interrogator 1 is received by the transmission / reception antenna 24, and the received signal is used as an electric signal for SAW.
The electric signal transmitted to the input electrode 22 of the element 21 is converted into a surface acoustic wave by the piezoelectric effect of the SAW element 21 and propagated to the output electrode 23.
Surface acoustic wave signal pattern input by and output electrode 2
The peak output is obtained when the weighting pattern of 3 matches. With this peak output signal, it is possible to confirm the agreement with the target PN code transmitted from the interrogator 1 and to give a signal to the power supply control unit 4 or the control unit 6.

In the above, when recording a specific code on the output electrode 23 of the SAW element 21, the output electrode 2
Since all matching codes are written in the phase of the electrode array by trimming of 3, additional writing is impossible,
Even if added, the transponder 2 itself cannot be used.

Also, since it is difficult to restore the electrodes, as a result, it is possible to reliably prevent additional writing and falsification of the specific code. Further, between the metal thin film layer 27 of the transponder 2 and the transparent protective layer 30, a concealing layer 29 and a printing layer which are transparent to infrared rays and ultraviolet rays are provided,
Further, by printing the visual recognition information on the surface of the protective layer 30, it is possible to make the pattern of the specific code recorded on the metal thin film layer 27 unreadable by visible light, and as a result, it is possible to visually recognize it. Therefore, it is possible to make reading of the recorded pattern almost impossible.

As described above, in the present embodiment, the microwave emitted from the interrogator 1 provided in the moving body such as the vehicle or the article to be transported and having the data transmitting / receiving function installed in the fixed station is received. And, in the responder 2 for the mobile body identification device, which adds the individual information to this microwave and transmits again to the interrogator 1, receives the microwave BPSK-modulated by the PN code from the interrogator 1, A SAW fixed code matched filter unit 11 that generates a burst signal when this matches a specific code previously recorded in the SAW element 21, and a responder based on the burst signal generated from the SAW fixed code matched filter unit 11. 2 is provided with a start signal generator 12 that generates a start signal for starting a circuit inside the main body.

Therefore, even when a plurality of transponders 2 exist within the communicable area of the interrogator 1, information can be surely communicated only with the transponder 2 to be communicated without causing interference, and The responder 2 of No. 1 does not require the operation of determining whether or not the responder 2 is required to communicate as in the conventional method described above, and the control unit 6 and other communication system circuit units in this period are not required. Since the power consumption is completely eliminated, it is possible to eliminate wasteful power consumption, save power, and maintain the battery life inside the transponder 2 for a longer time.

The SAW fixed code matched filter section 11 is located relatively near the surface of the transponder 2, and the input and output electrodes provided on the surface acoustic wave element are removed by an external heat beam such as a laser beam. Processing (trimming)
Since the specific code is recorded, the rewriting is impossible, and even if it is rewritten, the transponder 2 itself cannot be used. Therefore, it is possible to surely prevent fraud and improve security. It will be possible.

Further, unlike the conventional method described above, in which the identification code is written in the ROM area, mass productivity is improved, and more versatile manufacturing is possible.
Further, since the specific code is recorded and weighted as the individual information of the body of the responder 2, the responder 2 can be differentiated and ranked, so that the application can be expanded.

Further, on the surface of the SAW element 21 of the SAW fixed code matched filter portion 11 buried near the surface of the body of the transponder 2, the separation layer 28, the concealing layer 29, and the protective layer 3 are formed.
Since 0s are sequentially laminated, it is impossible to visually recognize the specific code pattern in the SAW fixed code matched filter unit 11 by printing the concealing layer 29, which further enhances security. It is possible to improve.

(Second Embodiment) FIG. 6 is a schematic block diagram showing an example of the configuration of a moving body identifying apparatus to which the transponder according to the present embodiment is applied. The same elements as those in FIG. 1 are designated by the same reference numerals. The description thereof will be omitted and only different parts will be described here.

That is, as shown in FIG. 6, the moving body identifying apparatus according to the present embodiment has the activation signal generator 1 in FIG.
2 is omitted, and instead of this, an information determination unit 20 is provided.

Here, the information judging section 20 detects the presence / absence of a burst signal generated from the SAW fixed code matched filter section 11, and when it is detected that this burst signal is present, the inside of the transponder 2 main body is detected. A determination signal is generated for the control unit 6 including the CPU, that is, an information signal indicating that the process execution of the control unit 6 is continued is given.

Next, the operation of the moving body identifying apparatus to which the transponder 2 of the present embodiment configured as described above is applied will be described. In FIG. 6, the responder 2 receives the microwave Fc emitted from the interrogator 1, the microwave detector 3 detects that the microwave has a predetermined level, and gives a signal to the power supply controller 4. Then, the power supply control unit 4 operates so as to supply power to each circuit.

Next, in the inquiry information from the interrogator 1,
The microwave Fc modulated by including the specific code or address of the transponder 2 to be communicated is received, reproduced by the detection / amplification / demodulation unit 10, and sent to the control unit 6.

Then, the control section 6 compares it with its own individual code or address stored in the ROM area or the memory section 7. As a result, if the two match, the response information is returned to the interrogator 1 side via the modulator 17, and the communication is continued.

If they do not match, a signal is given to the power supply control unit 4 to operate so as to immediately shift to the power saving mode. The above operation is the same as in the case of the first embodiment, but the apparatus of the present embodiment can further improve security, and an example thereof will be briefly described below.

By the above-mentioned operation, the transponder 2 that matches the individual code and address in the transponder 2 enters the communication state with the interrogator 1 and returns the response information to the interrogator 1. Next, the interrogator 1 emits a microwave Fc BPSK-modulated with a specific PN code to the responder 2.

On the other hand, in the responder 2, this microwave Fc
Is received and the SAW fixed code matched filter unit 11 matches the code, a burst signal is generated, and the information determination unit 20 sends the determination signal to the control unit 6 based on this. Then, the control unit 6 operates to determine the determination signal and continue communication with the interrogator 1.

However, when the SAW fixed code matched filter unit 11 does not match the code, the information judging unit 20
Therefore, the control unit 6 gives a signal to the power supply control unit 4 to immediately stop the communication state.

In this way, the interrogator 1 has each responder 2
Since the responder 2 can be selected by the PN code in addition to the information such as the individual code and the address, the security is further enhanced as compared with the conventional device.

The SAW fixed code matched filter section 11 of the transponder 2 is relatively near the surface of the transponder 2,
The input electrode and the output electrode provided on the surface acoustic wave element are removed (trimmed) by a heat beam such as a laser beam from the outside, a specific code is recorded, and weighted as individual information of the responder 2. Therefore, it is possible to write only once, and it is impossible to rewrite by fraudulent acts. Therefore, fraudulent acts are surely prevented and security is further enhanced.

As described above, in the present embodiment, the microwave emitted from the interrogator 1 provided in the moving body such as the vehicle or the article to be transported and having the data transmitting / receiving function installed in the fixed station is received. And, in the responder 2 for the mobile body identification device, which adds the individual information to this microwave and transmits again to the interrogator 1, receives the microwave BPSK-modulated by the PN code from the interrogator 1, A SAW fixed code matched filter unit 11 that generates a burst signal when this matches a specific code recorded in the SAW element 21 in advance, and the presence or absence of the burst signal generated from the SAW fixed code matched filter unit 11 are detected. When it is detected that this burst signal is present,
An information determination unit 20 for providing a determination signal (an information signal for continuing the processing execution of the control unit 6) to the control unit 6 including the CPU inside the responder 2 main body is provided.

Therefore, even when a plurality of transponders 2 are present within the communicable area of the interrogator 1, it is possible to surely communicate information only with the transponder 2 to be communicated without causing interference.

Further, the present transponder 2 can be applied to a device which does not use the conventional SAW fixed code matched filter unit, and further, the present device can be used in addition to the information such as the individual code and address of each conventional transponder. Since the responder 2 can be selected by the PN code, it is possible to further improve the security as compared with the conventional device.

On the other hand, the SAW fixed code matched filter section 11 is located relatively near the surface of the transponder 2, and the input and output electrodes provided on the surface acoustic wave element are removed by a heat beam such as a laser beam from the outside. Processing (trimming)
Since the specific code is recorded, the rewriting is impossible, and even if it is rewritten, the transponder 2 itself cannot be used. Therefore, it is possible to surely prevent fraud and improve security. It will be possible.

Further, unlike the conventional method described above, in which the identification code is written in the ROM area, mass productivity is improved, and more versatile manufacturing is possible. Furthermore, since a specific code is recorded and weighted as individual information of the body of the transponder 2, the transponder 2 can be differentiated and ranked, so that the application can be expanded.

Furthermore, the SA of the SAW fixed code matched filter portion 11 embedded near the surface of the transponder 2 body is SA.
Since the separation layer 28, the concealing layer 29, and the protective layer 30 are sequentially laminated on the surface of the W element 21, if the concealing layer 29 is printed or the like, the specific code pattern in the SAW fixed code matched filter unit 11 can be obtained. Since it becomes impossible to visually recognize it, it is possible to further improve the security.

In each of the above embodiments, the case where the activation signal generation unit 12 and the information determination unit 20 are individually provided in the transponder 2 has been described, but the present invention is not limited to this. Even when the 12 and the information determining section 20 are provided in the same transponder 2 at the same time, the present invention can be similarly applied to obtain the same effect as the above case.

[0105]

As described above, according to the invention according to claim 1, the interrogator having the data transmitting / receiving function, which is provided in a moving body such as a vehicle or an article to be transported and is installed in a fixed station, is used. In a transponder for a mobile body identification device, which receives an emitted radio wave, adds individual information to the radio wave, and transmits again to the interrogator, a pseudo noise (P
N) SAW fixed code matched filter means for receiving a radio wave binary-phase-modulated by a code and generating a burst signal when the radio wave is matched with a specific code previously recorded in a surface acoustic wave element (SAW element), Since a start signal generating means for generating a start signal for activating a circuit inside the responder main body is provided based on the burst signal generated from the SAW fixed code matched filter means, it is provided within the communicable area of the interrogator. Even if there are multiple transponders, information can be reliably communicated with only a specific transponder without interference, and unnecessary power consumption is eliminated to save power and extend the internal battery life. It is possible to provide a transponder for a moving body identification device that can be held for a longer time.

Further, according to the invention corresponding to claim 2,
Receives radio waves emitted from an interrogator that is installed in a moving body such as a vehicle or transported article and has a data transmission / reception function installed in a fixed station, adds individual information to the radio wave, and sends it to the interrogator again. In the transponder for a mobile body identification device, the radio wave which is binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received, and this is recorded in advance in the surface acoustic wave element (SAW element). The SAW fixed code matched filter means for generating a burst signal when it matches the code of No. 1 and the presence or absence of the burst signal generated by the SAW fixed code matched filter means are detected, and when it is detected that the burst signal is present, Since the control unit including the CPU inside the transponder body is provided with the information judging means for giving the information for continuing the processing execution, Even if there are multiple transponders in the communicable area of the interrogator, information can be reliably communicated only with a specific transponder without interference, and security can be improved. A transponder for a mobile body identification device can be provided.

Further, according to the invention corresponding to claim 3, the radio wave emitted from the interrogator provided in the moving body such as the vehicle or the article to be transported and having the data transmitting / receiving function installed in the fixed station is received. In addition, in the transponder for the mobile body identification device, which adds the individual information to the radio wave and transmits it to the interrogator again, the radio wave that is binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received. , Based on the burst signal generated from the SAW fixed code matched filter means and the SAW fixed code matched filter means for generating a burst signal when this coincides with a specific code recorded in advance on the surface acoustic wave element (SAW element). Generated by the SAW fixed code matched filter means and the start signal generating means for generating the start signal for activating the circuit inside the transponder body. The presence or absence of the burst signal, and when the presence of the burst signal is detected, the information judging means for giving information to the control unit consisting of the CPU inside the responder main body to continue the processing execution. Since it is equipped, even if there are multiple transponders in the communication area of the interrogator, it is possible to reliably communicate information with only a specific transponder without interference, and waste power consumption. It is possible to provide a transponder for a moving object identifying device, which can save power consumption by maintaining the internal battery life for a long time, and can improve security.

On the other hand, according to the invention corresponding to claim 4,
In the transponder for a moving body identifying device according to any one of claims 1 to 3, the input electrode and the output electrode provided on the surface acoustic wave element of the SAW fixed code matched filter means are replaced by a laser. By removing (trimming) with a heat beam such as a beam, a specific code is recorded and weighted as individual information of the transponder body, further improving security and mass production. It is possible to provide a transponder for a moving body identifying device, which can be manufactured more versatilely with an improved property.

According to the invention corresponding to claim 5,
In the responder for a moving body identifying device according to any one of claims 1 to 4, the surface acoustic wave element of the SAW fixed code matched filter means is embedded near the surface of the responder body, and On the surface of the surface acoustic wave element, a separation layer having a window portion that forms a void, a concealable layer that conceals the recorded information recorded in the surface acoustic wave element and that transmits infrared rays, and a transparent layer. Since the protective layers are sequentially laminated, it is possible to provide a transponder for a moving body identifying device which can further improve security.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a first embodiment of a transponder for a moving body identifying apparatus according to the present invention.

FIG. 2 is a circuit diagram showing an equivalent circuit of a SAW fixed code matched filter unit in the transponder for a moving body identifying apparatus according to the first embodiment.

FIG. 3 is a perspective view showing an example of an input electrode and an output electrode provided in the SAW element of the SAW fixed code matched filter unit in the transponder for a moving body identification device according to the first embodiment.

FIG. 4 is a diagram illustrating SAW of individual code patterns by a laser beam in the transponder for a moving body identifying apparatus of the first embodiment.
FIG. 6 is a vertical cross-sectional view for explaining a step of forming an output electrode of an element.

FIG. 5: SAW individual code patterns by a laser beam in the transponder for a moving body identifying apparatus of the first embodiment.
FIG. 6 is a plan view for explaining a step of forming an output electrode of the element.

FIG. 6 is a schematic block diagram showing a second embodiment of a transponder for a moving body identifying apparatus according to the present invention.

FIG. 7 is a schematic block diagram showing a configuration example of a conventional moving body identifying apparatus.

FIG. 8 is a schematic block diagram showing another configuration example of a conventional moving body identifying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Interrogator, 2 ... Responder, 3 ... Microwave detection part, 4 ... Power supply control part, 5 ... Power supply part, 6 ... Control part, 7 ... Memory part, 8 ... Data pattern generation part, 8 ... Condition determination part , 10 ... Detection / amplification / demodulation unit, 11 ... SAW fixed code matched filter unit, 12 ... Activation signal generation unit, 13 ... PN code generation unit, 14 ... Composite modulation unit, 15 ... Microwave oscillation unit, 16 ... Control Part (interrogator side), 17 ... Modulation part, 18 ... Reception detection part, 19 ... Demodulation part, 20 ... Information determination part, 21 ... SAW element, 22 ... Input electrode, 23 ... Output electrode, 24 ... Transmitting / receiving antenna, 25 ... metal base material, 26 ... dielectric layer, 27 ... metal thin film layer, 28 ... separation layer, 28a ... window part, 29 ... concealment layer, 30 ... protective layer, 31 ... trimming part, 32 ... laser beam, Fc ... micro Wave, Fr ... Microwave (anti Wave).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location H03H 9/25 H04B 7/26 E 9/42 H04B 7/26

Claims (5)

[Claims] 1. A radio wave emitted from an interrogator provided on a moving body such as a vehicle or an article to be transported and installed in a fixed station and having a data transmitting / receiving function, and adds individual information to the radio wave. In the transponder for mobile body identification device, which is transmitted again to the interrogator, the radio wave binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received, and this is received in advance by the surface acoustic wave element (SAW). SAW fixed code matched filter means for generating a burst signal when it matches a specific code recorded in the element, and a circuit inside the transponder body based on the burst signal generated from the SAW fixed code matched filter means. A responding device for a moving object identifying device, comprising: a starting signal generating means for generating a starting signal for starting the. 2. A radio wave emitted from an interrogator provided in a mobile body such as a vehicle or an article to be transported and having a data transmission / reception function installed in a fixed station, and adds individual information to the radio wave. In the transponder for mobile body identification device, which is transmitted again to the interrogator, the radio wave binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received, and this is received in advance by the surface acoustic wave element (SAW). SAW fixed code matched filter means for generating a burst signal when it matches a specific code recorded in the element, and the presence or absence of the burst signal generated from the SAW fixed code matched filter means is detected, When it is detected that there is an information determination hand, which gives information to the control unit composed of the CPU inside the transponder main body that the processing execution is to be continued. If, mobile identification device for responder, characterized in that it comprises an. 3. A radio wave emitted from an interrogator provided on a mobile body such as a vehicle or an article to be transported and having a data transmission / reception function installed in a fixed station, and adds individual information to the radio wave. In the transponder for mobile body identification device, which is transmitted again to the interrogator, the radio wave binary-phase-modulated by the pseudo noise (PN) code from the interrogator is received, and this is received in advance by the surface acoustic wave element (SAW). SAW fixed code matched filter means for generating a burst signal when it matches a specific code recorded in the element, and a circuit inside the transponder body based on the burst signal generated from the SAW fixed code matched filter means. And a presence of a burst signal generated from the SAW fixed code matched filter means. Of the burst signal, and when it is detected that the burst signal is present, information determining means for giving information to the control section composed of the CPU inside the transponder body to continue the execution of the processing, A transponder for a mobile body identification device, which is characterized by: 4. The transponder for a mobile body identification device according to claim 1, wherein an input electrode and an output provided on the surface acoustic wave element of the SAW fixed code matched filter means. A response for a moving body identifying device, characterized in that a specific code is recorded and weighted as individual information of the transponder body by removing (trimming) the electrode with a heat beam such as a laser beam. vessel. 5. The transponder for a mobile body identification device according to claim 1, wherein the surface acoustic wave element of the SAW fixed code matched filter means is provided near a surface of a transponder body. A separation layer that is embedded and has a window portion that forms a void on the surface of the surface acoustic wave element, that conceals the recorded information recorded in the surface acoustic wave element, and that allows printing by transmitting infrared rays. A transponder for a moving body identifying device, wherein a layer and a transparent protective layer are sequentially laminated.