WO2019065061A1

WO2019065061A1 - Chipless rfid tag, tag reader, and rfid system

Info

Publication number: WO2019065061A1
Application number: PCT/JP2018/032041
Authority: WO
Inventors: 平岡　三郎; 勝一浦谷
Original assignee: コニカミノルタ株式会社
Priority date: 2017-09-29
Filing date: 2018-08-30
Publication date: 2019-04-04

Abstract

This chipless RFID tag (1) makes it possible for a tag reader (2) to use reflected waves from radiated electromagnetic waves to read identification information and is provided with: a substrate (10) that is transparent with respect to the electromagnetic waves; an identification information formation section (11) that forms the pattern of an area within a predetermined surface of the substrate (10) in which the reflection characteristics with respect to the electromagnetic waves differ from those of the substrate (10) and in which the identification information is formed by the pattern; and a calibration information formation section (12) forming an area within the predetermined surface of the substrate (10) in which the reflected waves that are generated have different forms when the electromagnetic waves are radiated from the front surface side of the substrate (10) and when the electromagnetic waves are radiated from the rear surface side of the substrate (10).

Description

Chipless RFID tag, tag reader, and RFID system

The present disclosure relates to chipless RFID tags, tag readers, and RFID systems.

Conventionally, a barcode is known as an example of a tag that links information and the like related to an item. Since barcodes are inexpensive, they are currently printed on various articles, and are widely used as a means for digitizing information on the articles. On the other hand, in the case of a barcode tag, in order to read the printed content correctly, it is necessary to bring the barcode reader close to the barcode to about several centimeters, and this reading operation is felt by the operator to be complicated. In addition, there is also a problem that when the printed portion of the bar code is dirty, the printed content can not be read. In addition, since the barcode is printed at a visible position on the surface of the article, there is also a problem that the barcode can be easily rewritten to something malicious.

On the other hand, conventionally, an IC chip built-in type electronic tag and the like are also known. However, such an electronic tag has a problem in cost because it is necessary to provide an IC chip. Further, the transmission wave transmitted from the IC chip to the RFID reader is easily scraped off by the metal parts or the like disposed close to each other, and it becomes difficult to secure high readability.

In recent years, a tag called a "chipless RFID tag" has been attracting attention as a technology to replace a barcode and an IC chip built-in type electronic tag (see, for example, Patent Document 1).

The chipless RFID tag changes the reflection characteristics (for example, the resonance frequency and the intensity pattern of the reflected wave) when irradiated with the electromagnetic wave by the pattern formed on the base material, thereby identifying the information Configure. Then, the tag reader reads the identification information attached to the chipless RFID tag by detecting the reflection characteristic when the chipless RFID tag is irradiated with the electromagnetic wave.

Japanese Patent Publication No. 2009-529724

By the way, in recent years, in an RFID system using a chipless RFID tag (hereinafter, abbreviated as “tag”), it is considered to use a high frequency electromagnetic wave such as a millimeter wave of several tens of GHz at the time of reading. Such high frequency electromagnetic waves (hereinafter referred to as "electromagnetic waves") have the property of transmitting general packaging materials (for example, paper materials etc.), and therefore, may be applied to an aspect different from conventional barcodes etc. It is possible.

The inventors of the present application use the characteristics of such high frequency electromagnetic waves to align the front and back of the tag, for example, as in the case of matching in a state where the tag is housed inside the packing material. We thought of application to RFID system that enables verification without.

However, when considering application to such an application, in addition to the configuration that enables the pattern formed on the tag to be read from either the front or back, a configuration for determining the front or back of the pattern formed on the tag is required. There is a fear. That is, if the tag reader erroneously discriminates the front and back of the tag, the pattern formed on the tag is erroneously recognized.

The present disclosure has been made in view of the above problems, and it is an object of the present disclosure to provide a chipless RFID tag, a tag reader, and an RFID system that can read identification information from either front or back.

The main present disclosure to solve the above-mentioned problems is
A chipless RFID tag that causes a tag reader to read identification information by a reflected wave to an emitted electromagnetic wave,
A substrate having permeability to the electromagnetic wave;
An identification information forming unit that forms a pattern of an area in which the reflection characteristic to the electromagnetic wave is different from that of the base material in a predetermined plane of the base material, and the identification information is configured by the pattern;
In the predetermined plane of the substrate, a region that generates the reflected wave in a different aspect in the case where the electromagnetic wave is irradiated from the front side of the substrate and the case where the electromagnetic wave is irradiated from the back side of the substrate A calibration information formation unit to be formed;
A chipless RFID tag.

And in other aspects,
A tag reader applied to the above chipless RFID tag,
A tag reader which discriminates the identification information of the identification information formation unit by discriminating the front and back of the pattern of the identification information formation unit based on the mode of the reflected wave when the electromagnetic wave is irradiated to the calibration information formation unit It is.

And in other aspects,
It is an RFID system provided with the above-mentioned chipless RFID tag.

According to the chipless RFID tag according to the present disclosure, identification information can be read from either front or back.

FIG. 1A and FIG. 1B are diagrams showing an example of the configuration of the RFID system according to the first embodiment. FIGS. 2A and 2B are diagrams showing an example of an image pattern of a tag detected by the tag reader. FIG. 3 is a diagram showing an example of the configuration of the tag according to the first embodiment. FIG. 4A and FIG. 4B are views showing an example of an image pattern of a tag detected by a tag reader and a calibration pattern in the first embodiment. 5A and 5B are diagrams showing another aspect of the calibration pattern. FIG. 6 is a diagram showing an example of the configuration of a tag reader according to the second embodiment. FIG. 7 is a flowchart showing an example of the operation of the tag reader according to the second embodiment. 8A, 8B, and 8C are diagrams showing the configuration of a calibration information forming unit according to a modification of the first embodiment. FIG. 9A, FIG. 9B, FIG. 9C, FIG. 9D is a figure which shows another example of the image pattern of the tag detected by the tag reader. FIG. 10A and FIG. 10B are diagrams showing an example of the configuration of a second calibration information forming unit according to the second embodiment. FIG. 11 is a flowchart showing an example of the operation of the tag reader according to the second embodiment. 12A and 12B are diagrams showing the configuration of a tag according to Modification 1 of the second embodiment. FIG. 13A and FIG. 13B are diagrams showing the configuration of a tag according to a modification 2 of the second embodiment. FIG. 14A, FIG. 14B, and FIG. 14C are diagrams showing the configuration of the tag according to the third modification of the second embodiment.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functions will be assigned the same reference numerals and redundant description will be omitted.

First Embodiment
[RFID system configuration]
First, an example of the RFID system according to the first embodiment will be described with reference to FIG.

FIG. 1 is a diagram showing an example of the configuration of the RFID system U according to the first embodiment.

The RFID system U according to the present embodiment is configured to include the tag 1 and the tag reader 2.

The tag 1 according to the present embodiment is the above-described chipless RFID tag. The tag 1 is formed with a pattern of a region in which the reflection characteristic when irradiated with an electromagnetic wave is different from that of the base material of the tag 1.

In FIG. 1, as an example of the configuration of the tag 1, a member (for example, the metal member 11 a) and the electromagnetic wave having a high electromagnetic wave reflectivity (represents the ratio of the energy of the reflected wave from the tag to the energy of the transmitted electromagnetic wave). The aspect which comprises identification information with the pattern (Hereafter, it is also called an "image pattern") of the member (for example, electromagnetic wave absorption material 11b) with a low reflectance is shown (refer FIG. 1B).

The tag reader 2 outputs an electromagnetic wave of high frequency (for example, a millimeter wave band of 10 GHz to 3 THz) to irradiate the tag 1. Then, the tag reader 2 receives the reflected wave reflected from the tag 1 and recognizes, for example, an area in which the reflected wave is strong as “1” and an area in which the reflected wave is weak as “0”. Then, the tag reader 2 reads the image pattern formed on the tag 1 and the identification information corresponding to the image pattern based on the strength and weakness pattern of the reflected wave.

In addition, since the tag reader 2 uses a high frequency electromagnetic wave, it transmits and receives the electromagnetic wave by transmitting the packing material P even when the tag 1 is disposed inside the packing material P (for example, a cardboard). be able to. In addition, even when the tag 1 is embedded in the living body, the tag reader 2 can transmit and receive electromagnetic waves by transmitting the living body in the same manner.

In FIG. 1A, the tag 1 represents the state accommodated in the packaging material P with articles | goods (for example, articles | goods, such as clothes, foodstuffs, etc.). Here, in the packaging material P, the tag 1 is attached to the article in a state of being vertically erected so that the image pattern faces the front side of the packaging material P.

FIG. 2 is a view showing an example of the image pattern of the tag 1 detected by the tag reader 2.

FIG. 2A shows an image pattern detected when the tag reader 2 irradiates an electromagnetic wave from the surface side of the tag 1. On the other hand, FIG. 2B shows an image pattern detected when the tag reader 2 irradiates an electromagnetic wave from the back side of the tag 1.

As can be seen from FIGS. 2A and 2B, the tag reader 2 detects an inverted image pattern when detecting an image pattern from the front side of the tag 1 and when detecting an image pattern from the back side of the tag 1. Do. Then, if it is attempted to read the identification information of the tag 1 based on the inverted image pattern, the tag reader 2 will be misrecognized.

The tag 1 according to the present embodiment, in view of the problem, in addition to the image pattern (corresponding to the “identification information forming unit” of the present invention), a correction pattern (see FIG. 2) Not shown, which corresponds to the “correction information forming unit” of the present invention (described later with reference to FIG. 3).

In FIG. 2A and FIG. 2B, the tag 1 forms an image pattern by eight unit sections, with the area surrounded by a square as a unit section (hereinafter also referred to as a “pixel area”). In FIGS. 2A and 2B, address codes (“a” to “h”) are given to each pixel area, and pixel areas having the same address code correspond to the same position in the tag 1. (The same applies to FIG. 4, FIG. 5, FIG. 9, FIG. 10, FIG. 12, FIG. The black pixel area and the white pixel area are areas having different reflection characteristics (for example, the strength of the reflected wave). For example, the black pixel area is “1”, and the white pixel area is It is recognized by the tag reader 2 as “0”.

[Tag configuration]
FIG. 3 is a view showing an example of the configuration of the tag 1 according to the present embodiment.

The tag 1 according to the present embodiment includes a base 10, an identification information forming unit 11 that forms an image pattern in the base 10, and a calibration information forming unit 12 that forms an index of front / back discrimination in the base 10. And including.

The base 10 is, for example, a plate-like member on which an image pattern or the like is formed. The base material 10 is made of a material (for example, a resin material) at least a part of which can transmit electromagnetic waves of high frequency so that the matching operation can be performed from either the front surface side or the back surface side of the tag 1. However, as long as the base material 10 has a certain degree of electromagnetic wave transmittance, its shape, material, etc. are arbitrary.

In addition, the base material 10 which concerns on this embodiment uses a material about the middle of the electromagnetic wave reflectance of the metal member 11a and the electromagnetic wave reflectance of the electromagnetic wave absorption material 11b from a viewpoint of contrast with the metal member 11a and the electromagnetic wave absorption material 11b. It is done.

The identification information forming unit 11 is, for example, the above-mentioned image pattern, and in a predetermined plane of the substrate 10, forms a pattern of a region having a reflection characteristic to electromagnetic waves different from that of the substrate 10, and configures identification information by the pattern Do.

The identification information formation part 11 which concerns on this embodiment is the metal member 11a and electromagnetic wave absorption which were formed in the pixel area (eight pixel areas in FIG. 3) which divided the inside of the predetermined plane of the base material 10 into a plurality of pixels. It is comprised by the material 11b. The identification information forming unit 11 forms the image pattern 11 with, for example, the pixel area in which the metal member 11a is formed as an identification code of “0” and the pixel area in which the electromagnetic wave absorbing material 11b is formed as an identification code of “1”. doing.

The metal member 11a is, for example, an aluminum material, a copper material, or the like. The metal member 11a has a high electromagnetic wave reflectivity (for example, 80% or more), and generates a reflected wave to the extent that the tag reader 2 can easily acquire the radiated electromagnetic wave.

The metal members 11 a are pattern-formed separately for each pixel area in pixel areas (here, pixel areas of addresses “b”, “g”, “h”) on the base material 10. The metal member 11a is formed by, for example, an inkjet using an ink containing metal nanoparticles.

The electromagnetic wave absorbing material 11 b has a property of absorbing the energy of the electromagnetic wave transmitted by the tag reader 2 and attenuating the energy of the electromagnetic wave. Examples of the electromagnetic wave absorbing material 11 b include materials such as a magnetic body, a conductive material, carbon, inorganic fine particles, metal fine wires, or an electromagnetic wave absorbing resin. In addition, as the electromagnetic wave absorbing material 11b, one that converts energy of an electromagnetic wave into thermal energy, one that has a property of canceling energy by using the phase of the electromagnetic wave (for example, λ / 4 type radio wave absorbing material), or Energy may be dissipated by scattering electromagnetic waves.

The electromagnetic wave absorbing material 11 b is divided into pixel areas on the substrate 10 (here, pixel areas of addresses “a”, “c”, “d”, “e”, “f”) for each pixel area. , Patterned. The electromagnetic wave absorbing material 11 b is formed by, for example, an inkjet using an ink containing a magnetic material.

The identification information forming unit 11 according to the present embodiment increases the contrast of the reflected wave of each pixel region by thus forming the image pattern 11 using the combination of the electromagnetic wave absorbing material 11 b and the metal member 11 a, The tag reader 2 can easily detect the image pattern.

However, the material of the identification information forming unit 11 is not limited to this, and the base material 10 itself may be formed with a pattern having different reflection characteristics from other regions.

The proofreading information formation unit 12 is an index for making the tag reader 2 discriminate the front and back of the tag 1. The calibration information forming unit 12 differs in the aspect of the reflected wave in the case where the electromagnetic wave is irradiated from the surface side of the substrate 10 and the case where the electromagnetic wave is irradiated from the back surface side of the substrate 10 within a predetermined plane of the substrate 10 An area is formed, which constitutes an index of the front / back discrimination.

The calibration information forming unit 12 according to the present embodiment is formed of a pattern of a metal member covering the surface of the base material 10. The calibration information forming unit 12 according to the present embodiment uses, for example, the same material (here, the metal member 11 a) as the identification information forming unit 11 from the viewpoint of simplification of the manufacturing process.

The pattern of the calibration information forming unit 12 (hereinafter also referred to as “calibration pattern 12”) is a tag in the case where the electromagnetic wave is irradiated from the front side of the substrate 10 and the case where the electromagnetic wave is irradiated from the back side of the substrate 10 A shape to be detected as an inverted pattern in the reader 2 is selected. The calibration pattern 12 is, for example, a pattern that exhibits an asymmetrical shape at least in the left-right direction with reference to the vertical direction (representing the height direction; the same applies to the following) of the surface of the substrate 10 and the left-right direction. In FIG. 3, as an example of the calibration pattern 12, an isosceles triangle whose apex angle is directed to the right is shown.

The calibration information forming unit 12 is formed at a position around the image pattern 11 so as to be detected together with the image pattern 11 when the tag reader 2 scans the image pattern 11.

FIG. 4 is a view showing an example of an image pattern 11 and a calibration pattern 12 of the tag 1 detected by the tag reader 2 according to the present embodiment.

FIG. 4A corresponds to the image pattern 11 and the calibration pattern 12 detected when the tag reader 2 irradiates an electromagnetic wave from the front side of the tag 1, and FIG. 4B shows the electromagnetic wave from the back side of the tag 1 to the tag reader 2. Corresponds to the image pattern 11 and the calibration pattern 12 detected when the light is irradiated (the same applies to FIGS. 5A and 5B described later).

As can be seen from FIGS. 4A and 4B, since the calibration pattern 12 has an asymmetrical shape in the left-right direction, it is reversed between when the electromagnetic wave is irradiated from the front side and when the electromagnetic wave is irradiated from the back side. It is detected as a shape. That is, the tag reader 2 can determine the front and back of the tag 1 by identifying the direction of the calibration pattern 12.

When the tag reader 2 determines the front and back of the tag 1, the tag reader 2 detects the calibration pattern 12 from the intensity pattern of the reflected wave or the like (for example, using a known template matching or the like). Determine the direction of the pattern of. For example, as shown in FIG. 4A, when the tag reader 2 detects the calibration pattern 12 (isosceles triangle) whose apex angle is directed to the right, the tag reader 2 determines that the tag 1 is facing the surface. When the tag reader 2 detects the calibration pattern 12 (isosceles triangle) whose apex angle is leftward as shown in FIG. 4B, the tag reader 2 determines that the tag 1 is facing the back.

However, the calibration pattern 12 is optional as long as it is asymmetric in the left-right direction.

FIG. 5 is a view showing another aspect of the calibration pattern 12.

The calibration pattern 12 of FIG. 5 is configured by an array of two or more separate shapes. More specifically, the calibration pattern 12 of FIG. 5 has two line shapes extending vertically, which are arranged along the left-right direction. The calibration pattern 12 has an asymmetrical shape in the left-right direction because the lengths of the two linear shapes in the vertical direction are different. In addition, in FIG. 5, the base material 10 is shown in the permeation | transmission state for the facilities of description.

In FIGS. 4 and 5, the reason why the calibration pattern 12 has an asymmetrical shape in the left-right direction is that the main aspect requiring the front / back discrimination of the tag 1 is the surface of the tag 1 as shown in FIG. 11) is a case in which the packaging material P is directed to the front side or the rear side.

[Tag reader configuration]
Next, the configuration of the tag reader 2 will be described with reference to FIGS. 6 and 7.

FIG. 6 is a diagram showing an example of the configuration of the tag reader 2 according to the present embodiment.

The tag reader 2 has a function as a discrimination device for discriminating identification information based on the intensity pattern of the electromagnetic wave reflected by the tag 1, and as shown in FIG. 6, the electromagnetic wave transmission unit 21, the electromagnetic wave reception unit 22 and the operation An input unit 24, a display unit 23, a storage unit 25, a control unit 20, and the like are provided.

The electromagnetic wave transmission unit 21 includes an electronic circuit for generating a wireless signal, an antenna for transmission, and the like, and transmits an electromagnetic wave of a predetermined frequency in the range of 10 GHz to 3 THz (centimeter wave to millimeter wave to far infrared) described above. It functions as an electromagnetic wave transmitter.

In the present embodiment, the electromagnetic wave transmission unit 21 transmits an electromagnetic wave of a specific frequency, but may be configured to sweep a predetermined frequency band.

The electromagnetic wave receiving unit 22 includes an antenna for reception, an electronic circuit, and the like, and functions as an electromagnetic wave reflected wave receiver that receives a signal of a reflected wave of the electromagnetic wave transmitted by the electromagnetic wave transmitting unit 21. The electromagnetic wave receiving unit 22 is provided at a position corresponding to the reflection angle of the electromagnetic wave on the surface of the tag 1. The electromagnetic wave receiving unit 22 supplies the received signal of the reflected wave to the control unit 20. The peak point of the reception sensitivity in the electromagnetic wave reception unit 22 is set to the same frequency as the transmission frequency in the electromagnetic wave transmission unit 21.

The display unit 23 is configured of, for example, a liquid crystal display (LCD). The display unit 23 displays various operation screens and identification information configured in the tag 1 in accordance with a display control signal input from the control unit 20.

The operation input unit 24 includes various switches such as a power switch for turning on and off the main power supply and an irradiation switch for irradiating an electromagnetic wave, receives various input operations by the user, and outputs an operation signal to the control unit 20 Do.

The storage unit 25 is configured by a non-volatile semiconductor memory or a hard disk drive, and stores control programs and various data.

The control unit 20 includes a central processing unit (CPU) 20S, a read only memory (ROM) 20T, a random access memory (RAM) 20U, and the like. The CPU 20S reads out a program corresponding to the processing content from the ROM 20T, expands it in the RAM 20U, and controls the operation of each block of the tag reader 2 in cooperation with the expanded program. At this time, various data stored in the storage unit 25 are referred to.

The control unit 20 analyzes the signal of the reflected wave input from the electromagnetic wave receiving unit 22 to obtain image data of the tag 1 as a target of reading (reflection characteristics of the entire area of the base 10 including the image pattern 11). The same applies to the following, and the process of decoding and displaying the identification information configured in the tag 1 from the image data is executed.

The control unit 20 includes an electromagnetic wave reflection information reading unit 20a, an image information conversion unit 20b, a tag front / back discrimination unit 20c, and an identification information reading unit 20d.

The electromagnetic wave reflection information reading unit 20 a causes the electromagnetic wave transmission unit 21 to output an electromagnetic wave, and causes the electromagnetic wave reception unit 22 to detect the intensity or the like of the reflected wave. Then, the electromagnetic wave reflection information reading unit 20a reads the reflection characteristic (also referred to as electromagnetic wave reflection information) of each position of the tag 1 by executing such control so as to scan in a two-dimensional plane.

The image information conversion unit 20 b converts the electromagnetic wave reflection information of each position of the read tag 1 into an image pattern 11. At this time, the image information conversion unit 20 b converts the electromagnetic wave reflection information into the image pattern 11 also for the position of the calibration pattern 12 in addition to the position of the image pattern 11. Note that, for example, image data in which the coordinates of the image pattern 11 and the intensity of the reflected wave at the coordinates are associated with each other is generated by the process of the image information conversion unit 20 b.

Similar to the image information conversion unit 20b, the tag front / back discrimination unit 20c identifies a calibration pattern from electromagnetic wave reflection information. Then, based on the reflected wave acquired from the calibration information forming unit 12 of the tag 1, the tag front / back discrimination unit 20c discriminates whether the electromagnetic wave is applied to the tag 1 from the front side or the back side. Do.

The identification information reading unit 20d recognizes the identification information from the image information (also referred to as coding) after setting the reading direction of the image pattern 11 based on the judgment result of the front / back judgment of the tag front / back judging unit 20c.

FIG. 7 is a flowchart showing an example of the operation of the tag reader 2 according to the present embodiment. The flowchart in FIG. 7 is, for example, processing executed by the control unit 20 in response to the operation of the operation input unit 24 of the tag reader 2.

In step S10, the control unit 20 causes the electromagnetic wave transmission unit 21 to transmit an electromagnetic wave and irradiates the tag 1 with the electromagnetic wave reception unit 22 sequentially (for example, the reflected wave from the tag 1). To detect the intensity). Then, the control unit 20 switches the transmission direction of the electromagnetic wave transmission unit 21 and the reception direction of the electromagnetic wave reception unit 22, and scans over a predetermined area where the image pattern 11 of the tag 1 is considered to be formed. Thereby, the control unit 20 generates the reflected wave information (here, the intensity information of the reflected wave) for each position of the area where the image pattern 11 of the tag 1 and the calibration pattern 12 are formed.

In this step S10, first, the pattern of the reference point (not shown) of the tag 1 is searched for and the intensity of the electromagnetic wave to be transmitted by calibration is checked before the process of detecting the reflected wave information is executed. Adjustments of may be performed.

In step S20, the control unit 20 generates image data of the tag 1 based on the reflected wave information. Here, for example, the control unit 20 converts “1” when the intensity of the reflected wave is large, and converts “0” when the intensity of the reflected wave is small. When the intensity of the reflected wave is intermediate, the control unit 20 recognizes it as a region of the base 10 as a region not to be converted.

In step S30, the control unit 20 extracts the calibration pattern 12 from the image data of the tag 1 by, for example, known template matching. Then, based on the orientation of the calibration pattern 12 (the orientation of the apex angle of the isosceles triangle), the control unit 20 applies an electromagnetic wave to the tag 1 from the front side or from the back side to the tag 1. It is determined whether or not an electromagnetic wave has been emitted.

In step S40, the control unit 20 sets the reading direction of the image data 11 based on the judgment result of the front / back judgment of the tag front / back judgment unit 20c, and decodes the identification information from the image pattern.

[effect]
As described above, according to the tag 1 according to the present embodiment, the base 10 having permeability to electromagnetic waves is used, and the calibration information forming unit 12 determines the front and back of the tag reader 2 with respect to the tag reader 2. It can be done. As a result, even when the tag reader 2 or the like irradiates the tag 1 with an electromagnetic wave from either the front side or the back side, the identification information of the tag 1 can be read accurately.

(Modification of the first embodiment)
FIG. 8 is a diagram showing a configuration of the calibration information forming unit 12 according to a modification of the first embodiment.

8A and 8B respectively show the identification information forming unit 11 and the calibration information forming unit 12 as viewed from the front side of the tag 1, and the identification information forming unit 11 and the calibration information forming unit 12 as viewed from the back side of the tag 1. ing. In addition, the base material 10 is shown in the permeation | transmission state here for the facilities of description.

The calibration information forming unit 12 according to the present modification includes the electromagnetic wave reflectivity when the tag 1 is irradiated with the electromagnetic wave from the front side and the electromagnetic wave from the back side to the tag 1 in the partial region of the base material 10. The calibration information forming unit 12 according to the first embodiment is different from the calibration information forming unit 12 according to the first embodiment in that an index for discriminating front and back is configured by making the electromagnetic wave reflectance different from that when irradiated.

8C shows the reflection intensity (solid line) of the electromagnetic wave in the calibration information forming unit 12 (electromagnetic wave absorbing material 11b) when the electromagnetic wave is irradiated to the tag 1 from the front side, and the electromagnetic wave is irradiated to the tag 1 from the back side. The reflected intensity (dotted line) of the electromagnetic wave in the calibration information formation part 12 (electromagnetic wave absorption material 11b) at the time of having performed is each shown.

That is, the calibration information formation unit 12 according to the present modification is not limited to the image pattern 11 (in FIGS. 8A and 8B, the pixel areas of the addresses “a”, “c”, “d”, “e” and “f”). It is comprised by the electromagnetic wave absorption material 11b to form. In other words, the electromagnetic wave absorbing material 11b has different electromagnetic wave transmittances (however, it is larger than 0% and smaller than 100%) in the case where the electromagnetic wave is irradiated from the front side and the case where the electromagnetic wave is irradiated from the rear side. Is configured as.

The means for realizing this aspect is optional, but for example, the material forming the electromagnetic wave absorbing material 11b has directivity of the electromagnetic wave absorptivity, or an electromagnetic wave reflector is provided on the front or back surface of the electromagnetic wave absorbing material 11b. It is possible to use a method of forming asperities on the surface or the back surface of the electromagnetic wave absorbing material 11b.

As described above, according to the tag 1 according to the present modification, the area for forming the calibration information forming unit 12 can be omitted, which contributes to the miniaturization of the tag 1.

As a matter of course, the material of the base 10 and the metal member 11a may be provided with directivity of the electromagnetic wave transmittance and the electromagnetic wave reflectivity instead of the aspect of the above-described modification.

Second Embodiment
Next, a tag 1 according to a second embodiment will be described with reference to FIGS. 9 to 11.

The tag 1 according to the present embodiment is added to the calibration information forming unit 12 (hereinafter referred to as “first calibration information forming unit 12” or “first calibration pattern 12”) which is an index for discriminating front and back. In that the calibration information forming unit 13 (hereinafter referred to as the “second calibration information forming unit 13” or the “second calibration pattern 13”) serving as an index for determining the upper and lower This is different from the embodiment of FIG. Description of the configuration common to the first embodiment will be omitted.

In the tag 1 according to the first embodiment, the first calibration information forming unit 12 configures an index for discriminating front and back. However, depending on the attachment position of the tag 1, as a result of the tag 1 rotating 180 degrees and the upper and lower sides of the image pattern 11 being reversed, the image pattern 11 may not be identified accurately only by the index of the front / back discrimination.

FIG. 9 is a view showing another example of the image pattern 11 of the tag 1 detected by the tag reader 2 (in FIG. 9, the first calibration information forming unit 12 and the second calibration information forming unit 13 Not shown).

FIG. 9A shows an image pattern 11 (a tag reader 2 detects a tag 1 when an electromagnetic wave is applied to the tag 1 in the normal position (the tag 1 is not rotated; the same applies to the following)). Fig. 2 shows the same as Fig. 2A). FIG. 9B shows an image pattern 11 (similar to FIG. 2B) detected by the tag reader 2 when an electromagnetic wave is applied to the tag 1 in the normal position from the back side. FIG. 9C shows an image pattern 11 detected by the tag reader 2 when an electromagnetic wave is irradiated from the front side to the tag 1 in a state of being rotated 180 degrees. FIG. 9D shows an image pattern 11 detected by the tag reader 2 when an electromagnetic wave is irradiated from the back side to the tag 1 rotated 180 degrees.

As can be seen from FIGS. 9A to 9D, the image pattern 11 of the tag 1 may be recognized as four different patterns by rotating the tag 1 by 180 degrees.

The state in which the tag 1 is rotated by 90 degrees can be determined from the aspect ratio of the image pattern 11 and the base material 10, so that only the state rotated by 180 degrees is a problem here.

From this point of view, the tag 1 according to the present embodiment is provided with a second calibration information forming unit 13 constituting an index for upper and lower discrimination, in addition to the first calibration information forming unit 12 for discriminating front and back. There is.

FIG. 10 is a diagram showing an example of the configuration of the second calibration information forming unit 13. As shown in FIG. 10A shows the tag 1 in the normal position, and FIG. 10B shows the tag 1 rotated 180 degrees.

The second calibration information forming unit 13 is configured of, for example, a pattern of the metal members 11 a having an asymmetrical shape in the vertical direction with reference to the vertical direction and the horizontal direction of the surface of the tag 1.

In FIG. 10, as an example of the pattern of the second calibration information forming unit 13, an isosceles triangle in which the apex angle is directed upward is shown. That is, as can be seen from FIGS. 10A and 10B, since the second calibration information forming unit 13 has an asymmetrical shape in the vertical direction, the electromagnetic wave is rotated 180 degrees when it is irradiated at the normal position. When irradiated in the state, it is detected as an inverted shape. The tag reader 2 identifies the orientation of the second calibration information forming unit 13 (whether it is an isosceles triangle with the apex angle directed upward or an isosceles triangle with the apex angle directed downward). , The top and bottom of the tag 1 can be determined.

Note that, as described in the first embodiment, the first calibration information forming unit 12 is configured by, for example, a pattern having an asymmetrical shape in the left-right direction in order to configure an index for discriminating front and back.

That is, by combining the first proofreading information formation unit 12 and the second proofreading information formation unit 13, the tag reader 2 determines which state of the four image patterns 11 shown in FIGS. 9A to 9D. It becomes possible to distinguish.

FIG. 11 is a flowchart showing an example of the operation of the tag reader 2 according to the present embodiment. In addition, in FIG. 11, only the details of the process of the front / back discrimination of step S30 of FIG. 7 are shown.

In step S31, the control unit 20 extracts the first calibration pattern 12 and the second calibration pattern 13 from the image data of the tag 1 by, for example, known template matching.

In step S32, the control unit 20 irradiates the tag 1 with an electromagnetic wave from the front side based on the direction of the first calibration pattern 12 (the direction of the apex angle of the isosceles triangle) or the tag 1 It is determined whether the electromagnetic wave has been irradiated from the back side. Then, when the control unit 20 determines that the electromagnetic wave is irradiated to the tag 1 from the front side (step S32: Yes), the process proceeds to step S33. On the other hand, when the control unit 20 determines that the electromagnetic wave is not irradiated to the tag 1 from the front side, that is, the electromagnetic wave is irradiated from the back side (step S32: No), the process proceeds to step S36.

In step S33, the control unit 20 determines whether the tag 1 is not rotated with respect to the normal position based on the orientation of the second calibration pattern 13 (the orientation of the apex angle of the isosceles triangle). Do. When the control unit 20 determines that the tag 1 is not in the rotation state with respect to the normal position (step S33: Yes), it recognizes the identification information from the image pattern 11 (see FIG. 9A) as it is (step S34). On the other hand, when the control unit 20 determines that the tag 1 is rotated with respect to the normal position (step S33: No), an image pattern (see FIG. 9C) is rotated 180 degrees (see FIG. After conversion to 9 A), the identification information is recognized (step S35).

In step S36, the control unit 20 similarly causes the tag 1 to rotate with respect to the normal position based on the orientation of the second calibration pattern 13 (the orientation of the apex angle of the isosceles triangle). Determine if it is When the control unit 20 determines that the tag 1 is not in the rotation state with respect to the normal position (step S36: Yes), the image pattern 11 (see FIG. 9B) is axisymmetric pattern (see FIG. 9A) And then identify the identification information (step S37). On the other hand, when the control unit 20 determines that the tag 1 is in the rotational state with respect to the normal position (step S36: No), a pattern obtained by rotating the image pattern 11 (see FIG. 9D) by 180 degrees After conversion to FIG. 9A), the identification information is recognized (step S38).

[effect]
As described above, according to the tag 1 according to the present embodiment, the first calibration information forming unit 12 and the second calibration information forming unit 13 are provided. As a result, both the front / back discrimination and the upper / lower discrimination (rotational state discrimination) of the tag 1 can be made, so that the tag reader 2 can be made to recognize more accurate identification information.

(Modification 1 of the second embodiment)
FIG. 12 is a diagram showing the configuration of the tag 1 according to the first modification of the second embodiment. The tag 1 according to the present modification is different from the second embodiment in the pattern shape of the second calibration information forming unit 13.

12A shows an image pattern 11 detected when the tag 1 is in the normal position as in FIG. 10A (same as in FIG. 13A and FIG. 14A described later), and FIG. 12B is similar to FIG. 10B. The image pattern 11 detected when the tag 1 is rotated 180 degrees is shown (the same applies to FIGS. 13B and 14B described later).

The pattern shape of the second proofreading information formation unit 13 according to the present modification is configured by an array of two or more separated shapes. More specifically, in the pattern of the second calibration information forming unit 13, two line shapes extending in the left and right direction are arranged along the vertical direction. The pattern of the second calibration information forming unit 13 has a shape that is asymmetric in the vertical direction because the lengths in the left-right direction of the two linear shapes are different.

Even when the second calibration information forming unit 13 has such a pattern shape, the same effect as that of the above embodiment can be obtained.

(Modification 2 of the second embodiment)
FIG. 13 is a view showing the configuration of a tag 1 according to a second modification of the second embodiment. The tag 1 according to the present modification is different from the second embodiment in the pattern shape of the second calibration information forming unit 13.

In the tag 1 according to this modification, the first calibration information forming unit 12 and the second calibration information forming unit 13 are integrally configured.

More specifically, the first calibration information forming unit 12 and the second calibration information forming unit 13 according to the present modification are asymmetric in the left-right direction and in the vertical direction. More specifically, the first calibration information forming unit 12 and the second calibration information forming unit 13 have a pattern in which two line shapes extending vertically are arranged in the left-right direction, and the two lines Due to the difference in the length of the shape in the vertical direction, the shape is asymmetric in the horizontal direction. The calibration information forming unit 12 and the second calibration information forming unit 13 form a shape which is asymmetric in the vertical direction by forming a linear shape extending in the left and right directions on the upper part of the two linear shapes.

(Modification 3 of the second embodiment)
FIG. 14 is a view showing the configuration of the tag 1 according to the third modification of the second embodiment. The tag 1 according to the present modification is different from the second embodiment in that the second calibration information forming unit 13 is formed on the base material 10 itself.

More specifically, the base material 10 according to the present modification is formed so that the reflection intensity of the electromagnetic wave decreases stepwise from the upper end side to the lower end side of the base material 10, whereby the second calibration information is formed. The section 13 is configured (see T2-T2 'in FIG. 14C).

That is, in the present modification, when the tag 1 is in the normal position, the tag reader 2 detects the reflection intensity of the electromagnetic wave of the base 10 so as to gradually decrease from the upper end to the lower end. When the tag 1 is rotated 180 degrees, the reflection intensity of the electromagnetic wave of the base material 10 is detected so as to gradually decrease from the lower end side toward the upper end side.

As described above, by configuring the second calibration information forming unit 13 on the base material 10 itself, it is not necessary to separately provide a region of the calibration pattern, which contributes to the miniaturization of the tag 1.

(Other embodiments)
The present invention is not limited to the above embodiment, and various modifications can be considered.

In the said embodiment, an example of a structure of the tag 1 was variously shown. However, as a matter of course, various combinations of the modes shown in each embodiment may be used.

Moreover, in the said embodiment, the aspect comprised with the pattern of the member from which the electromagnetic wave reflectance differs formed in the predetermined plane of the base material 10 as an example of the identification information formation part 11 was shown. However, the identification information formation part 11 should just be a pattern in which the reflective characteristic with respect to electromagnetic waves differs from the base material 10, and can be changed into various aspects.

For example, when the identification information forming unit 11 constructs one piece of identification information, it replaces the strength (amplitude) of the electromagnetic wave reflectance of each member (for example, the metal member 11a or the electromagnetic wave absorber 11b) from the members. A phase shift of the reflected wave may be used. The phase shift of the reflected wave can be given, for example, by adjusting the film thickness of the metal.

The identification information forming unit 11 may use the frequency characteristics of each member (for example, the metal member 11a or the electromagnetic wave absorber 11b) when configuring one piece of identification information. The frequency characteristic of the member for the electromagnetic wave to be irradiated can be, for example, a resonant frequency given by the pattern shape of the metal member 11a or a frequency to be absorbed by changing the composition ratio of the electromagnetic wave absorber 11b as a specific frequency It is.

Further, the identification information forming unit 11 may use a combination of reflection characteristics of a plurality of sections (for example, a shape formed by an arrangement pattern) when configuring one piece of identification information.

Although the specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above.

The disclosures of the specification, drawings and abstract included in the Japanese application of Japanese Patent Application No. 2017-190579 filed on Sep. 29, 2017 are all incorporated herein by reference.

U RFID system 1 tag 10 base material 11 identification information formation unit (image pattern)
11a metal member 11b electromagnetic wave absorbing material 12 calibration information forming unit (pattern for calibration)
13 Second calibration information formation unit (second calibration pattern)
2 tag reader 20 control unit 21 electromagnetic wave transmission unit 22 electromagnetic wave reception unit 23 display unit 24 operation input unit 25 storage unit

Claims

A chipless RFID tag that causes a tag reader to read identification information by a reflected wave to an emitted electromagnetic wave,
A substrate having permeability to the electromagnetic wave;
An identification information forming unit that forms a pattern of an area in which the reflection characteristic to the electromagnetic wave is different from that of the base material in a predetermined plane of the base material, and the identification information is configured by the pattern;
In the predetermined plane of the substrate, a region that generates the reflected wave in a different aspect in the case where the electromagnetic wave is irradiated from the front side of the substrate and the case where the electromagnetic wave is irradiated from the back side of the substrate A calibration information formation unit to be formed;
, Chipless RFID tag.
The calibration information forming unit is a pattern of a region in which the reflection characteristic to the electromagnetic wave is different from that of the base material, and the pattern is at least in the left-right direction with reference to the vertical direction and the left-right direction of the predetermined surface of the base material. It has an asymmetric shape,
The chipless RFID tag according to claim 1.
The asymmetrical shape is configured by two or more shapes arranged along the left-right direction.
The chipless RFID tag according to claim 2.
The calibration information forming unit is configured to generate the reflected wave in the case where the electromagnetic wave is irradiated from the front side of the base and the case where the electromagnetic wave is irradiated from the rear side of the base in the predetermined plane of the base. It is an area where reflection intensity is different,
The chipless RFID tag according to claim 1.
The electromagnetic wave transmittance of the calibration information forming unit is larger than 0% and smaller than 100%.
The chipless RFID tag according to claim 4.
The case where the electromagnetic wave is irradiated when the predetermined surface of the substrate is in the normal position, and the case where the electromagnetic wave is irradiated when the predetermined surface of the substrate is rotated 180 degrees from the normal position , And a second calibration information forming unit that generates the reflected waves in different modes,
The chipless RFID tag according to any one of claims 1 to 5.
The second calibration information forming unit is a pattern of a region in which the reflection characteristic to the electromagnetic wave is different from that of the substrate, and the pattern is based on the vertical direction and the lateral direction of the predetermined surface of the substrate. It has an asymmetrical shape at least in the vertical direction,
The chipless RFID tag according to claim 6.
The pattern of the second calibration information forming unit is configured in two or more shapes arranged along the vertical direction.
The chipless RFID tag according to claim 7.
The second calibration information forming unit is a region in which the reflection intensity of the reflected wave with respect to the electromagnetic wave is different between the upper side and the lower side in the predetermined plane of the base material.
The chipless RFID tag according to claim 6.
The electromagnetic wave transmittance of the second calibration information forming unit is larger than 0% and smaller than 100%.
The chipless RFID tag according to claim 9.
The calibration information forming unit and the second calibration information forming unit are configured with an asymmetrical shape in any of the vertical direction and the horizontal direction based on the vertical direction and the horizontal direction of the predetermined surface of the base material. The chipless RFID tag according to any one of claims 6 to 8.
The calibration information forming unit and the second calibration information forming unit are configured by an array of three or more separated shapes.
The chipless RFID tag according to claim 11.
The identification information forming unit includes a pattern of a metal member formed in the predetermined surface of the base, and a pattern of an electromagnetic wave absorbing material formed in the predetermined surface of the base.
The chipless RFID tag according to any one of claims 1 to 12.
The pattern of the identification information forming unit has a shape in which the inside of the predetermined plane of the base material is divided into a plurality of pixels.
The chipless RFID tag according to any one of claims 1 to 13.
The electromagnetic wave is an electromagnetic wave of any frequency in a frequency band of 10 GHz to 3 THz,
The chipless RFID tag according to any one of claims 1 to 14.
A tag reader applied to the chipless RFID tag according to any one of claims 1 to 15, comprising:
A tag reader which discriminates the identification information of the identification information formation unit by discriminating the front and back of the pattern of the identification information formation unit based on the mode of the reflected wave when the electromagnetic wave is irradiated to the calibration information formation unit .
An RFID system comprising the chipless RFID tag according to any one of claims 1 to 15.