JPH02226086A - Non-contact discriminating apparatus - Google Patents

Abstract

PURPOSE:To make a responder compact and inexpensive by a method wherein part of electromagnetic waves from an interrogator is modulated by a modulator directly driven by a pulse signal generator and reflected, and the reflected waves from the responder are detected and amplified by the interrogator so that modulated frequency components are detected by a frequency detector to detect and discriminate the responder. CONSTITUTION:An interrogator 1a catches reflected waves from a responder 2a with an antenna 103, detects and amplifies waves to detect frequency with a frequency detector 106. When the frequency contained in a preset frequency bandwidth is detected, an external device control circuit 107 operates to drive a lamp, a buzzer, etc. to inform that the responder 2a having specific frequency as a discriminating sign has entered a detection region. Therefore a person having the responder 2a or an object provided with the responder 2a can be detected and discriminated as one group. This can simplify circuitry realizing a compact and inexpensive responder 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an identification device that uses electromagnetic waves to detect and identify people, objects, etc. in a non-contact manner.

[Conventional technology]

FIG. 4 is a schematic diagram showing the configuration of an example of a conventional non-contact identification device of this type.

In the figure, 1 is an interrogator, 101 is an oscillator, 102 is a circulator, 103 is an antenna, 104 is a detector, 10
5 is an amplifier, 2 is a responder, 201 and 202 are antennas,
203 is a detector, 204 is an amplifier, 205 is a switch equipped with a voltage comparator, 206 is a battery, 207 is a nofrus signal generator, 208 is a storage element, and 209 is a modulator.

This type of identification device usually uses electromagnetic waves in the microwave band or quasi-microwave band.

The electromagnetic waves generated by the oscillator 101 are transmitted to the circulator 10.
2 and then sent out into space through the antenna 103. The electromagnetic waves sent out into space form a detection area determined by the directional characteristics of the antenna 103 and the sent out power.

When a person carrying the transponder 2 or an object to which the transponder 2 is attached enters this detection area, the antenna 201 of the transponder 2 captures a portion of the electromagnetic waves sent out from the antenna 103.

Antenna 201, detector 203, amplifier 20 of transponder 2
4. The switch 205 is a power-saving circuit that is controlled to operate only when the transponder 2 enters the detection area of the electromagnetic waves transmitted by the interrogator 1.

When the antenna 201 captures the transmitted electromagnetic wave and the switch 205 is turned on, the All Soot signal generator 207 and the memory element 2
08 is activated, and the data registered in the memory element 208 is
modulator 209 as a voltage signal proportional to the logical values of l and O.
The electromagnetic waves applied to the antenna 202 and reflected by the antenna 202 are modulated.

The interrogator 1 captures the reflected wave from the transponder 2 with the antenna 103, detects and amplifies it, demodulates the modulated data, and detects and identifies the modulated data with a signal processing circuit (not shown).

By registering different data in the memory elements 208 of the transponder 2, the interrogator 1 can individually record the transponder 2, that is, the person carrying the transponder 2 or the object to which the transponder 2 is attached. can be identified.

[Problem to be solved by the invention]

The conventional non-contact identification device configured as described above has the advantage of being able to identify each transponder individually, but the purpose of the identification device is to
It is not necessarily necessary to identify each person individually; there are cases where it is only necessary to determine whether or not a transponder is in possession, or it is sufficient to determine by group.

For the above-mentioned applications, the conventional non-contact identification device has the problem that the transponder 2 is expensive due to the memory element 208, and it is difficult to miniaturize the transponder 2.

The present invention was made to solve the above problems.
The purpose is to provide a transponder that can be made small and inexpensive.

[Means to solve the problem]

In the non-contact identification device of the present invention, the transponder is configured to modulate and reflect a part of the electromagnetic waves from the interrogator using a modulator directly driven by a pulse signal generator, and the interrogator is configured to modulate and reflect a part of the electromagnetic waves from the interrogator. One is configured to detect, amplify, and detect the modulated frequency component with a frequency detector to detect and identify the transponder, and the other is a transponder with two pulse signal generators with different frequencies.
The interrogator is configured to modulate and reflect a part of the electromagnetic waves from the interrogator using an exclusive-OR circuit or a driving modulator that uses the pulse signal as an input signal, and the interrogator detects and amplifies the reflected wave from the responder. Toggle flip 70 with direct signal input
Toggle and signal input via inverter circuit
The frequencies of the pulse signals of the two Noculus signal generators of the responder are detected by frequency detectors connected to these toggle flip-flops via flip-flops, and
By selecting the frequency of the pulse signal of one pulse signal generator from n frequencies, the transponders divided into nC2 groups are detected and identified by group.

[Effect]

Since the memory element, which consumes a large amount of power and is expensive, is omitted, the power-saving circuit part can also be omitted, and the circuit configuration is simplified, the number of parts is reduced, and a transponder that can be easily miniaturized and is inexpensive can be obtained.

When detecting and identifying by group, the structure shown in claim 1 may be divided into groups according to the frequency of the pulse signal generator of the transponder, but if it is divided into many groups, a problem may occur. However, with the structure shown in claim 2, it becomes possible to detect and identify many groups.

〔Example〕

FIG. 1 is a block diagram showing the structure of an embodiment of the invention as set forth in claim 1.

In the figure, the same reference numerals as those in FIG. 4 indicate the same or corresponding parts, 1a is the interrogator, 2a is the responder, 106
107 is a frequency detector, and 107 is an external device control circuit.

In the responder 2a, since the output signal of the pulse signal generator 207 directly drives the modulator 209, the reflected wave reflected from the antenna 202 contains the frequency component of the pulse signal.

The interrogator 1a transmits the reflected wave from the transponder 2a to the antenna 10.
3, the frequency is detected by the frequency detector 106, and when a frequency included in a preset frequency band is detected, the external device control circuit 107 is activated and is driven to notify that the transponder 2a, whose identification code is a specific frequency, has entered the detection area.

The frequency detector 106 can be easily configured using a frequency-voltage converter (Cf-V converter), a 7A phase locked loop (PLL: phase locked loop), or the like.

When using an f-V converter, connect a voltage comparator to its output stage and set the bandwidth so that the output of the converter turns on when a specific frequency is detected. to form a wind co//layer.

On the other hand, when using a PLL, the holding range (lock range) is set so that the specific frequency to be detected is included within that range.
If set, a lock signal of the desired frequency will be output.

The external device control circuit 107 receives the output signal of the frequency detector 106 and controls the on/off of a display device connected to the outside of the interrogator 1a, and is composed of a contact opening/closing element such as a relay or a photocoupler. can do.

With the above configuration, it is possible to detect and identify a person carrying the transponder 2a or an object to which the transponder 2a is attached as one group.

Detection and identification of objects into multiple groups can be achieved by changing the pulse signal of the pulse signal generator 207 of the transponder 2a for each group.

On the other hand, the interrogator 1a has a multi-stage configuration including a frequency detector 106 and an external device control circuit 107. For example, in a frequency detector using an f-V converter, f -V cover 1
tD's next stage wind competition! Install the required number of controllers,
The frequency ranges to be detected are set to be shifted from each other, and the external device control circuit 107 is connected to each of them independently. Also,
In the frequency detector 106 using a PLL, a plurality of PLLs each having a different lock range are prepared, and an external device control circuit 107 is connected to each PLL independently.

- The pulse signal generator 207 is generally composed of an astable multivibrator using a timer IC, a CR oscillation circuit using an inverter IC, a crystal oscillation circuit also using an inverter IC, etc. Therefore, in order to change these oscillation frequencies, it is only necessary to change the circuit constants of the capacitor (C), the resistor (8), etc., or to replace the crystal resonator with a crystal resonator having a different resonance frequency.

This means that the code registration in the memory element, which was done conventionally,
Since it is not necessary to change the digital processing program in the signal processing circuit that processes the output signal of the interrogator, it greatly contributes to reducing manufacturing costs and improving user convenience.

On the other hand, in the pulse signal generator 207 using an 〇R oscillator using an inverter IC or an astable oscillator, there are large variations in the constants of C and R, which are frequency determining factors, and the threshold value of the IC.
Moreover, since it has temperature characteristics, the frequency varies widely and the temperature stability is poor. Therefore, the frequency detector 106 of the interrogator 1a detects the frequency/number f.

It must be structured to cover a fairly wide band with the center frequency as . Therefore, if the number of groups of transponders 2& is increased, the band of the amplifier 105 will be widened and the S/
The number of groups cannot be increased much because the N ratio will be poor.

In the pulse signal generator 207 using a crystal oscillation circuit, the crystal resonator is manufactured by the IJ lithography process, so different masks must be prepared to obtain resonators of different frequencies.

Note that there are methods of increasing the frequency by cutting the tuning fork of the vibrator using the same mask, or lowering the frequency by depositing metal on the tuning fork, but these methods are not suitable for mass production. Therefore, if the number of groups is increased too much, the cost will increase.

With the configuration of claim 2, the number of groups can be increased more easily than with the configuration of claim 1.

FIG. 2 is a block diagram showing the configuration of an embodiment of the invention as set forth in claim 2.

In this embodiment, the frequency of the nozzle signal generator of the responder is
．． Second. This is an example of detecting and identifying each group by selecting from the third three frequencies.

In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, 1b is an interrogator, 2b is a responder, 106
a, 106b, and 106c have the detection frequencies of 1st.
Second. third frequency frequency detector, 107a, 107
b, 107e are external device control circuits, 108 is an inverter circuit, 109m, 109b are toggle flip-flops, 110a, 110b, 110c, 110d.

110e and 110f are AND circuits, 1lla and 1llb
.

111ciJ1. The OR circuits 207m and 207b are/cell signal generators, and 210 is an exclusive OR circuit.

FIG. 3 is a timing waveform diagram showing an example of the timing of the pulse signal in the embodiment shown in FIG.

Noculus signal generators 207a, 20 of the responder 2b
The frequency of the ZEL signal of 7b is the first frequency 12, respectively.
d.

(Noculus width τ1.8 = 1/2τ,), second frequency f! The explanation will be given by taking as an example the case of (Zorth width τz, ft = 1/2τ2).

The pulse width τ1 shown in FIG. 3 (B). Due to the input of the cell wave of τ2, a pulse wave whose pulse width changes moment by moment appears at the output of the exclusive circuit 210, as shown in the diagram (Q).

Since the modulator 209 is driven by the pulse wave shown in Figure (C), when the interrogator 1b captures, detects and amplifies the reflected wave from the transponder 2a, the demodulated signal becomes the /lP pulse wave shown in Figure (Q). It becomes a pulse wave with the same frequency as .

The output of the amplifier 105 is divided into two, one directly to the toggle flip-flop (T-FFI) 109g, and the other to the falling edge of the toggle flip-flop (T-FF2) 109b via the inverter circuit 108.
It is connected to the clock input, and the falling edge of the demodulated signal is Sierra Zo and the rising edge is Shedge, respectively, inverting the output.

The demodulated signal appearing at the output of the amplifier 105 has a pulse width that changes over time, and there are stages in which the pulse width gradually widens and stages in which it gradually narrows.

At the stage where the pulse width is widening, a pulse wave with pulse width τ and (frequency f,) is output to the toggle flip-flop 109a, and the toggle flip-flop 7'109b
, a pulse wave with a pulse width of 41 τ, ([wave number f1) is output.

At the stage where the pulse width is narrowing, a pulse wave with a pulse width τ and (frequency ft) is output to the toggle flip-flop 109 &.
A pulse wave with a pulse width τ and a frequency f! is output at b (Figure (b)).

Therefore, Toggle Frizzo 7odde 109a.

If the outputs of 109b are observed at the same time, a pulse wave of frequency f1 is always output from one of them, and a pulse wave of frequency f2 is output from the other.

Frequency detectors 110a and 110b whose center frequencies are set to f, , f are connected in parallel to the outputs of toggle flip-flops f109h and 109b, respectively.
9b is a /e pulse wave of frequency 11 or frequency f
Whichever of the two d' pulse waves is output is detected by either the frequency detector 110a or 110b.

The outputs of frequency detectors 110a and 110b are connected to AND circuit 1.
The external device control circuit 107a is driven through 11a and 111b and the OR circuit 112a.

Pulse signal generators 207m, 207bcr) The external device control circuit 107a is driven for the transponder 2b whose pulse signal frequency is fI and ft, and the response to the transponder zb+12+ whose pulse signal frequency is fI - fs. external device control circuits 107b for the respective devices 2b;

107e is driven. f indicates the third frequency.

By increasing the number of frequencies selected, more groups of detection can be identified. For example, by selecting and combining six frequencies, it is possible to classify them into up to 6C2=15 groups.

〔Effect of the invention〕

As explained above, according to the present invention, the circuit becomes simple, the cost is reduced, the size can be easily reduced, and it is possible to easily detect and identify many groups by group. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the invention shown in claim 1, FIG. 2 is a block diagram showing the structure of an embodiment of the invention shown in claim 2, and FIG. FIG. 2 is a timing waveform diagram showing an example of the timing of the pulse signal in the embodiment shown in FIG. 4, and FIG. 4 is a block diagram showing the configuration of an example of this conventional non-contact identification device. Ia, lb... Interrogator, 101... Oscillator, 102
... Circulator, 103 ... Antenna, 104
...Detector, 105-...Amplifier, 106, 106a
, 106b. 106 c-frequency detector, 107, 107a, 107
b. 107c...External equipment control circuit, 1.08...In/output time Wr, 109m, 109b...Toggle/furisodefronog, 110a, 110b, 110c,
110d, 110e. 110 f-AND circuit, 111a, 111b, 111
e-OR circuit, 2m, 2b...responder, 202...
Antenna, 206-...Battery, 207,207g, 20
7b-knoll: x, signal generator, 209...modulator,
210... Exclusive-OR circuit. In the drawings, the same reference numerals indicate the same or contrasting parts. Patent applicant New Japan Radio Co., Ltd.

Claims (2)

[Claims] (1) The interrogator sends out electromagnetic waves into space, and when the transponder enters the detection area of the electromagnetic waves sent out by the interrogator, a part of the electromagnetic waves is modulated by a modulator directly driven by the pulse signal generator. The interrogator captures, detects and amplifies the reflected wave from the transponder, and a frequency detector detects a modulated frequency component to detect and identify the transponder. (2) An exclusive OR circuit in which the interrogator sends out electromagnetic waves into space, and when the responder enters the detection area of the electromagnetic waves sent out by the interrogator, the input signals are pulse signals from two pulse signal generators with different frequencies. A modulator driven by modulator modulates and reflects a part of the electromagnetic wave, and the interrogator captures, detects, and amplifies the reflected wave from the responder, and the signal is directly input to a toggle flip-flop and the signal is transferred to an inverter. Through a toggle flip-flop input through the circuit,
A frequency detector connected to each of these toggle flip-flops detects the frequency of the pulse signal of the two pulse signal generators of the above responder, and the frequency of the pulse signal of the above two pulse signal generators is determined from n frequencies. A non-contact identification device configured to detect and identify transponders divided into two groups by selecting them.