JPH10302031A - Identification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive identification(ID) system capable of resisting dirt or the like. SOLUTION: Plural resonation tags 1 are arranged on each target 7 to be identified. Two LC resonance circuits are loaded on one resonance tag 1 and fourty-two kinds of resonance tags can be prepared by the combination of response frequency bands of the two LC resonance circuits. Thereby each inherent ID code can be applied to each of plural targets 7 to be identified by combining plural resonance tags 1. Scanning waves are outputted from transmitting antennas 9 to resonate the tags 1 and their echo waves are received by a receiving antenna 10 consisting of matrix-like antenna elements 10e. These received signals are analyzed by an analyzer 8 to identify the ID code of the target 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for identifying a large number of objects and using the objects in various fields. The present invention relates to a system for identifying pallets, packing cases, and the like.

[0002]

2. Description of the Related Art A known identification system using a bar code or an IC tag is known. However, the bar code cannot be read if the bar code is dirty. Further, the IC tag may be damaged by impact or the like.

[0003] Therefore, there arises a technical problem to be solved in order to provide such an identification system which is hardly affected by external influences, and an object of the present invention is to solve the problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and one or a plurality of LC resonance circuit patterns each having a specific resonance frequency are provided on one substrate. Thereby, a resonance tag having one or a plurality of resonance frequencies per one is formed, a plurality of the resonance tags are arranged per one identification object, and the resonance tags are arranged at intervals from each other. A transmitting antenna that outputs a scan wave whose frequency increases or decreases toward the transmitting antenna, an antenna element that receives an echo wave from the resonance tag, a receiving antenna that is arranged in a matrix, and a receiving signal for each of the antenna elements. An object of the present invention is to provide an identification system provided with an analysis device for identifying the identification target by specifying a resonance tag arranged on the identification target.

Further, in such an identification system, a resonance tag having the same resonance frequency is arranged at a specific position for all the objects to be identified, so that the analysis device uses the resonance tag as a reference. Another object of the present invention is to provide an identification system configured to identify the identification target object while specifying the arrangement position of another resonance tag.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
4 to FIG. FIG. 1 shows an example of the resonance tag 1, and a substrate 2 of the resonance tag 1 is formed of an insulating hard synthetic resin into a thin disk shape having a diameter of about 35 mm. The circuit patterns 3a, 3b are formed on the front and back surfaces of the substrate 2 by etching a conductive foil or screen printing a conductive paste.
b, 3c and 3d are formed.

The circuit patterns 3a, 3b, 3c, and 3d are divided into left and right halves on one side of the substrate 2, respectively, and circulate in a semicircular spiral shape.
That is, the circuit pattern 3a and the circuit pattern 3c and the circuit pattern 3b and the circuit pattern 3d are formed so that most of the orbits overlap with the other orbits via the substrate 2 respectively. The inner and outer ends of these circuit patterns 3a, 3b, 3c, 3d are provided at the same position on the substrate 2 for those facing the front and back, and
Through holes 4a, 4b, 4c, 4d are formed at the end positions. The through holes 4a, 4b, 4c, 4
A conductive coating is applied to the inner peripheral surface of d.

Therefore, the through holes 4a, 4b, 4
c and 4d, the circuit patterns 3a, 3
c and 3b and 3d are continuous with each other to form a closed circuit. Specifically, the circuit pattern 3a and the circuit pattern 3c are continuous via the through holes 4a and 4b at both inner and outer ends to form a closed circuit, and the circuit pattern 3b and the circuit pattern 3d are formed at both inner and outer ends. Through holes 4c, 4
A closed circuit is formed by continuing through d. Each of these closed circuits functions as a coil having a predetermined inductance.

The circuit pattern 3 on the front side of the substrate 2
Capacitors 5a and 5b each having a predetermined capacitance are interposed in the vicinity of the inner ends of a and 3b. Thus, these closed circuits constitute LC resonance circuits 6a and 6b each having a predetermined resonance frequency. That is, one resonance tag 1 has two resonance frequencies by the two LC resonance circuits 6a and 6b. Then, a resist (not shown) is coated on both the front and back surfaces of the resonance tag 1 to protect it.

The resonance tag according to the present invention is not limited to the one shown in FIG. 1, and for example, only a circuit pattern without mounting a capacitor chip such as the capacitors 5a and 5b. An LC resonance circuit may be formed. That is, as a substrate material, for example, a rigid or film-like polymer dielectric having a predetermined dielectric constant is used, and a conductor circuit pattern having both a coil pattern and an electrode pattern of a capacitor is attached to both front and rear surfaces thereof. . In this case, it is possible to variously change not only the inductance but also the capacitance simply by changing the size and shape of the conductor circuit pattern, thereby simplifying the manufacturing process and improving the mass productivity because no capacitor chip is mounted. And the strength of the resonance tag can be sufficiently ensured.

When the resonance frequencies of the LC resonance circuits 6a and 6b are considered as a kind of symbol, an identification code can be created by a combination thereof, and the resonance tag 1
Has a two-digit identification code based on a combination of two types of symbols. In addition, the circuit patterns 3a,
If the shape of 3b, 3c, 3d or the capacitance of capacitors 5a, 5b is changed, the resonance frequency will be different.
There are theoretically infinite types of symbols, and an identification code, which is a combination of two digits, can also be infinite. Therefore, the resonance tag 1 classified by the difference of the identification code
Can be made infinitely in theory.

However, in practice, there is a limit to the Q value of resonance, and there is also a limit to the resolution on the side of analyzing the Q value. Furthermore,
Due to manufacturing variations and the like, if the resonance frequencies between the resonance circuits are too close, they will interfere with each other and analysis will not be possible. According to an experiment by the inventor, in this type of LC resonance circuit, it is necessary that the mutual center resonance frequencies are separated from the other frequency by ± 5 to 10% or more on average.

Therefore, if resonance is performed using a frequency band from 3 MHz to 50 MHz, for example, the type of a practically usable resonance circuit (the number of resonance frequencies that can be allocated)
Means around 10. Since two of the ten or so are selected and incorporated into the resonance tag, the type of the resonance tag as the identification code is about ₁₀ C ₂ = 45 by simple calculation. Of these, about three combinations are used as options. Hereinafter, it is assumed that there are 42 types of resonance tags 1 as identification codes in the embodiment of the present invention.

Incidentally, if the LC resonance circuit is formed in a fan shape so that the resonance tag is divided into three at 120-degree intervals, and three LC resonance circuits are mounted on one resonance tag, the type of the resonance tag becomes By simple calculation, the number increases to about ₁₀ C ₃ = 120.

FIG. 2 is a block diagram of a system for analyzing the identification code composed of the resonance tag 1, and FIG.
A plurality of resonance tags 1, 1... Are attached to each identification target 7, and the identification code of the identification target 7 is determined by the combination and arrangement (permutation) of the resonance tags 1, 1,. In other words, even if there are only 42 types of individual resonance tags 1, a plurality of them are combined to form an entire identification code, or if the same combination is processed in a different arrangement, the identification code is different. Can be increased additively. Thereby, the identification object 7,
No matter how large the number of 7 is, a unique identification code can be assigned to each of them.

Here, as specific examples of the identification object 7, various objects conventionally identified by a bar code, an IC tag, and the like, such as a container, a pallet, and a packing case in a physical distribution field, can be considered. Then, the identification object 7 includes the transmitting antenna 9 and the receiving antenna 1 extended from the analyzing device 8.
0, and the resonance tags 1, 1 ...
Is applied to the transmitting antenna 9 and the receiving antenna 10. As described later, if the arrangement surface of the resonance tags 1, 1... Is applied to the transmitting antenna 9 and the receiving antenna 10, the identification object 7 is placed at any position of the transmitting antenna 9 and the receiving antenna 10. It does not matter whether they are arranged at an appropriate angle (relative positional relationship).

On the other hand, the CPU 11 of the analyzer 8 outputs a high-frequency current from the transmission amplifier 14 to the distributor 15 by operating the frequency control circuit 12 and the timing control circuit 13. The frequency of this high-frequency current increases and decreases between 3 MHz and 50 MHz in a very small cycle. The transmitting antenna 9 is composed of a plurality of antenna elements 9e, 9e.
Each of the antenna elements 9e is connected to the distributor 15. In this way, a scan wave that increases or decreases in a very small cycle from 3 MHz to 50 MHz is output from each antenna element 9 e, 9 e.

When the instantaneous frequency of the scan wave matches the resonance frequency of each of the LC resonance circuits 6a, 6b of the resonance tags 1, 1, the LC resonance circuit 6a or 6b resonates and reflects an echo wave. This echo wave is received by the nearest one of the antenna elements 10e, 10e,... Constituting the receiving antenna 10, and the antenna elements 10e, 10e,. That is, the receiving antenna 10 also includes a plurality of antenna elements 10e, 10e... Like the transmitting antenna 9, and specifically, as shown in FIG. 3, a structure in which the antenna elements 10e, 10e. It has become.

The transmitting antenna 9 and the receiving antenna 10 are constituted by a microstrip line antenna having a predetermined pattern printed on a dielectric plate, a simple loop antenna made of a dielectric material, or the like. Also, in FIGS. 3A and 3B, the antenna elements 10e of the receiving antenna 10 are formed in a square shape, and they are combined in a lattice to form a matrix. Further, in FIG.
The transmitting antenna 9 for each antenna element 10e.
Are surrounded by each antenna element 9e,
The antenna element 9e of the transmitting antenna 9 and the antenna element 10e of the receiving antenna 10 correspond one-to-one. On the other hand, in FIG. 2B, the antenna elements 10e, 10e,
Every 10e ... is surrounded by each antenna element 9e of the transmitting antenna 9.

On the other hand, the receiving antenna 10 shown in FIG.
Has a matrix structure in which the antenna elements 10e, 10e... Are formed in a regular hexagonal shape and are combined in a honeycomb shape. .. Are surrounded by each antenna element 9e of the transmitting antenna 9 for each of the horizontal rows of antenna elements 10e.

The configurations of the transmitting antenna 9 and the receiving antenna 10 are not limited to these three types.
Antenna elements 10e, 10e of receiving antenna 10
.. Must have a matrix structure arranged vertically and horizontally because it is necessary to analyze the positional relationship between the resonance tags 1, 1. The density of the matrix needs to be sufficiently denser than the arrangement density of the resonance tags 1, 1,... If the matrix density is low, one antenna element 1
This is because an echo wave is incident on 0e from a plurality of resonance tags 1, 1,... And analysis becomes impossible. In other words, when arranging the resonance tags 1, 1,... On the identification target 7, the resolution capability of the receiving antenna 10 is not exceeded while taking into account the Q characteristics of the resonance tags 1, 1,. They must be spaced sufficiently apart.

FIG. 4 shows an example of the arrangement of the resonance tags 1, 1,... With respect to the identification object 7, and six resonance tags 1, 1,. However, they are arranged in a "six" pattern on the dice. And this 6
The identification code is determined by a combination of the resonance tags 1, 1,. However, since there are 42 types of identification codes of the individual resonance tags 1, there are ₄₂ C ₆ = 5,245,786 combinations to select 6 types from among them.
Also, the number of overlapping combinations is ₄₂ H ₆ = 10,737,573. That is, 5,245,786 to 10,737,
Each of the 573 identification objects 7, 7,... Can be assigned a unique identification code.

If the identification object 7 shown in FIG. 4 is described as the identification object 7 in FIG. 2 described above, the closest antenna element 10e in the receiving antenna 10 and the antenna around the antenna element 10e will be described. Element 10e, 10
are input from the antenna elements 10e, 10e to the analyzer 8. Then, the antenna elements 10e, 10e
Are amplified by the receiving amplifiers 16 connected in a one-to-one relationship to the phase comparators 18 via the selector 17 for each of the received signals from the antenna elements 10e.
And sent to the sample amplifier 19. The phase comparator 18 reads the phase difference between the received signal and the output signal from the transmitting amplifier 14, and the sample amplifier 19 samples the received signal. And the result is A / D
The digital signal is converted by the converter 20 and the CPU 11
Is input to

The CPU 11 identifies the type of the resonance tag 1 placed on the identification object 7 by analyzing which frequency of the scan wave reflects the echo wave based on the input information. When the types of all six resonance tags 1 are specified in this manner, an identification code obtained by combining the six types is specified, and thus the specific identification with the identification code is given. The object 7 is identified. By performing this operation for each of the identification objects 7, 7,..., 5,245,786 to 10,737,573 identification objects 7, 7,. If the number of resonance tags 1 arranged for one identification target 7 is increased, the number of identification targets 7, 7,... That can be identified further increases.

Further, of the six-eye arrangement of the dice in FIG. 4, a specific position deviated in any direction in the entire arrangement pattern, such as the position of the upper left corner in the figure. In
The identification code can be determined by arranging the same type of resonance tag 1A for all the identification objects 7, 7,. In this case, the CPU 11 performs analysis in consideration of not only the resonance frequency of each resonance tag 1A, 1, 1,... But also which antenna element 10e has received the echo wave. In this analysis process, techniques such as filtering, pattern matching, and correlation function processing individual identification similar to image processing are used.

Then, for all the echo waves reflected from the six resonance tags 1, 1..., The six antenna elements 10e, 10e. It is checked whether an echo wave from the resonance tag 1A has been received. When the position of the resonance tag 1A is determined in this way, the other five tags can be used with reference to the resonance tag 1A regardless of the relative positional relationship between the identification object 7 and the reception antenna 10. Are located at the respective positions of the object to be identified 7. For example, it turns out that the resonance duct 1 at a diagonal position with respect to the resonance tag 1A is arranged at the lower right corner of the identification target 7 in FIG. Thus, the identification code can be determined not only by the six combinations of the resonance tags 1, 1,... But also by their permutation and overlapping permutation.

That is, even in the case of the same combination of six resonance tags 1, 1... (One of them is fixed, substantially the combination of five resonance tags 1, 1,. Are different from each other, the identification code can be determined to be different. If so, the identifiable identification object 7,
The number of 7 is ₄₁ P ₅ = 89,927,7 in the case of the permutation arrangement.
In the case of 60 pieces and overlapping permutation arrangement, 41 ⁵ = 115,856,
It becomes 201. This is far more than the combinations and overlapping combinations described above, and is a sufficient number of identification codes.

The identification object 7 shown in FIG. 5 is configured such that the orientation of the identification object 7 can be recognized by the arrangement pattern of the six resonance ducts 1, 1,. In this case, the CP
U11 identifies the respective resonance tags 1, 1... From the resonance frequency, and also recognizes the arrangement pattern by an analysis method similar to the image processing described above. Thus, the orientation of the identification object 7 with respect to the receiving antenna 10 is determined. For example, in the arrangement pattern shown in FIG. 4, it is indistinguishable from the state rotated by 180 degrees unless there is a reference resonance tag such as the resonance tag 1A, but in the arrangement pattern shown in FIG. The direction will be specified.

Therefore, the identification object 7 and the receiving antenna 10
., Regardless of the relative positional relationship between them, it is determined which of the six resonance tags 1, 1... Therefore, the identification codes can be determined by the permutation arrangement or the overlapping permutation arrangement for all the six resonance tags 1, 1..., And the number of identification codes in that case is ₄₂ P ₆ = 3,776,96 in the permutation arrangement.
5,920, 42 ⁶ = 5,48 when overlapping permutation
9,031,744. That is, in the arrangement pattern shown in FIG. 4, the number of identification objects 7, 7,.
Can be identified.

Since the identification system is mediated by the electromagnetic waves of the scan wave and the echo wave, even if the surface of the resonance tag 1 is somewhat dirty or embedded in the identification object 7, As long as the dirt and the material of the identification object 7 are dielectric, the scan wave and the echo wave are not blocked. Therefore, unlike a bar code identification system, it is not impossible to identify.

Further, the resonance tag 1 is hardly affected by temperature, humidity, impact, and the like because of its structure. I do not receive it. Further, the resonance tag 1 is very inexpensive because it has only a passive circuit. Thus, an identification system that is less susceptible to external influences and that is inexpensive can be realized.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0033]

As described above, since the identification system according to the present invention mediates the electromagnetic waves of the scan wave and the echo wave, even if the surface of the resonance tag that receives the scan wave and reflects the echo wave is slightly dirty. Scan and echo waves are not blocked. Therefore, it does not become indistinguishable unlike a barcode.

In addition, the resonance tag is not easily affected by temperature and humidity due to its structure, and is not easily damaged by impact or the like, unlike an IC tag. Furthermore, it can be used by being embedded inside the object to be identified, and in that case, there is no direct mechanical or chemical action from the outside. Also, since the resonance tag is only a passive circuit, it is very inexpensive. Thus, it is possible to realize an inexpensive identification system that is hardly affected by external influences and that is inexpensive.

On the other hand, the number of resonance frequencies of a resonance tag is limited, and it cannot be used at all in a field where a large number of objects to be identified are handled as in a physical distribution system. By arranging a plurality of identification objects per identification object and analyzing them with a reception antenna composed of a matrix-shaped antenna element for each individual resonance tag, the number of identifications can be increased incrementally, It has become possible to respond sufficiently to fields such as distribution systems.

Further, according to the second aspect of the present invention, the identification code may be determined not only by the identification code based on the combination or the overlapping combination but also by the permutation arrangement or the overlapping permutation arrangement of other resonance tags excluding the reference resonance tag. Therefore, the number of identifiable objects to be identifiably increases dramatically.

[Brief description of the drawings]

FIG. 1 shows an example of a resonance tag, (a) is a plan view thereof, and (b) is a bottom view thereof.

FIG. 2 is an explanatory block diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory plan view showing a pattern example of a transmitting antenna and a receiving antenna.

FIG. 4 is an explanatory plan view showing an arrangement example of a resonance tag with respect to an identification target.

FIG. 5 is an explanatory plan view showing an arrangement example of a resonance tag with respect to an identification target.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resonance tag 2 Substrate 3a, 3b, 3c, 3d Circuit pattern 5a, 5b Capacitor 6a, 6b LC resonance circuit 7 Identification object 8 Analysis device 9 Transmitting antenna 10 Receiving antenna 10e Antenna element of receiving antenna

Claims (2)

[Claims] 1. A resonance tag having one or a plurality of resonance frequencies per one is formed by arranging one or a plurality of LC resonance circuit patterns each having a specific resonance frequency on one substrate. A transmitting antenna for arranging a plurality of resonance tags per one identification target and spaced apart from each other, and outputting a scan wave whose frequency increases or decreases toward the identification target; and an echo from the resonance tag. Antenna elements for receiving waves are arranged in a matrix, and a reception antenna, and a resonance tag arranged on the identification target based on a reception signal for each of the antenna elements are specified to identify the identification target. An identification system comprising an analysis device for identification. 2. Arranging a resonance tag having the same resonance frequency at a specific position for all of the identification targets, thereby arranging another resonance tag based on the resonance tag in the analysis device. 2. The identification system according to claim 1, wherein the identification object is identified while identifying the identification object.