JP2017033101A - Information medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information medium using a chip-less RFID which is large in information amount and size enough to substitute for a bar code.SOLUTION: The present invention relates to an information medium 1 comprising a plurality of dipole antennas 2 having different resonance frequencies in a frequency domain of the UHF band or higher. Further, the information medium is an information medium having dipole antennas in strip-like shapes. Further, the dipole antennas of the information medium are in the strip-like shapes differing in length and having the same width, lengthwise center positions of the strip-like shapes are arranged at equal intervals on one straight line orthogonal to the length direction of the strip-like shapes, and void parts are provided symmetrically about the center of the length direction of the strip-like shape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an information medium comprising a chipless RFID.

  A barcode or RFID is used as an information medium that carries attribute information of an article by being attached to the article.

  For example, in a supermarket or the like, a barcode is attached to a product, and a purchaser of the product takes an article to be purchased to a cash register in the supermarket. At the cash register, the person in charge reads the bar code attached to the item one by one with an optical reader to obtain information such as the item name and amount of the item purchased by the purchaser, and calculates the total amount and prints it. The system is out.

  On the other hand, RFIDs such as non-contact IC tags are used for entrance / exit management, railway and bus boarding cards, etc., and are attached to, for example, articles flowing through production lines in plants or storage boxes containing articles. As an information medium in which the reading / writing device at the measurement point in the process reads or writes information about the RFID, so that it can be known in real time where and in the process, Used in process management systems.

  An RFID such as a non-contact IC tag uses a semiconductor chip as an information medium, and thus it is difficult to reduce the cost. However, the amount of information that can be recorded is large, and information can be written. On the other hand, barcodes are very low cost and have already been put to practical use as information media even in supermarkets. However, the amount of information that barcodes can carry is relatively small, and there are disadvantageous features such as inability to write information. is there. Further, since the bar code is optical, it is necessary to read each one, so that it is impossible to read the goods at once.

  In order to realize the collective reading of products for improving the efficiency of cash registers in supermarkets and the like, it is essential to reduce the cost of information media using radio waves such as non-contact IC tags.

  As a technique for solving this problem, Patent Document 1 discloses an information medium that uses radio waves at low cost without using an IC chip. This technology uses a low-cost printing method such as gravure printing, and a plurality of portions are formed in the antenna with a conductive ink printed in a coil shape, and the divided portions are formed using digital printing technology such as inkjet printing. This is a technique for changing the resonance frequency of the antenna and carrying information by short-circuiting.

  Although this technique has a simple antenna configuration, a plurality of divided portions are formed over a wide range, so that the setting range of the resonance frequency is also wide. Therefore, the antenna on the reading device side needs to cover a wide range of frequencies, and there is a problem that the device becomes large. This technology assumes the HF band (3 MHz to 30 MHz), and an example is shown in which a dipole antenna having a resonance frequency of 9 MHz and an antenna length of 33 m is formed in an area of 4 cm × 4 cm. It is difficult to attach a plurality of information media of a large size to a small product.

Japanese Patent No. 5501601

  In view of the above circumstances, an object of the present invention is to provide an information medium using a chipless RFID having an information amount and a size that can replace a barcode.

  As means for solving the above-mentioned problems, the invention according to claim 1 of the present invention is characterized by comprising a chipless RFID including a plurality of dipole antennas having different resonance frequencies in a frequency region above the UHF band. Information medium.

  The invention according to claim 2 is the information medium according to claim 1, wherein the dipole antenna has a strip shape.

According to a third aspect of the present invention, the dipole antenna has a strip shape with different lengths and the same width, and the center position in the longitudinal direction of the strip shape is straight in a direction perpendicular to the longitudinal direction of the strip shape. On the line and at equal intervals,
The information medium according to claim 2, further comprising a hollow portion symmetrically from the longitudinal center of the strip shape.

  The invention according to claim 4 is the information medium according to claim 1, wherein the dipole antenna has an arc shape.

  According to a fifth aspect of the present invention, the dipole antenna is concentrically arranged at equal intervals, has an arc shape with notches in the same direction at the same plane angle, 5. The information medium according to claim 4, further comprising a hollow portion symmetrically along the arc from the position to be divided.

  According to the chipless RFID of the present invention, by providing a plurality of dipole antennas having different resonance frequencies in the frequency region above the UHF band, the chipless RFID having an information amount and a size that can replace a barcode is used. It is possible to provide an information medium.

A strip-shaped dipole antenna having the same width and different length used in the chipless RFID which is the information medium of the present invention is arranged in parallel, and a dipole antenna having a symmetrical hollow portion from the center in the length direction is used. It is a schematic plan view showing the case, (a) is arranged on each side of the longest dipole antenna (length L1) three dipole antennas of length L2, L3, L4 and L5, L6, L7, respectively. 7 configurations in total, (b) shows a configuration in which the dipole antenna of length L2 is missing from the configuration in (a), and (c) shows a configuration in which the dipole antenna of length L6 is missing from the configuration in (a). ing. The information of the configuration (a) in which all dipole antennas are aligned is assumed to be “0” when each dipole antenna is arranged, and “1” when the dipole antenna is not arranged. [0000000], (b) represents [0100000], and (c) represents [0000010]. These are examples of 3 numbers out of 7 bits = 128 numbers, indicating that they can be identified in this way. FIG. 6 is a schematic plan view showing an example in which six arc-shaped dipole antennas having the same width and different arc lengths used in the chipless RFID of the present invention are arranged concentrically, and symmetrically cut from the center of the arc. This is an example in which a dipole antenna having a portion is used. In this example, the concentric circular arcs have a constant plane angle from the center of the concentric circle, the arc notch has a constant plane angle, and each arc is L1 from the center of the concentric circle. , L2, L3, L4, L5, and L6. In the arc-shaped dipole antenna shown in FIG. 2, (a) is a configuration in which six dipole antennas are arranged, and (b) is the second (radius: L5) and fourth (radius: L3) dipole antenna from the inside. (C) is a configuration in which the first (radius: L6), third (radius: L4), and fifth (radius: L2) dipole antennas from the inside are not arranged, and each dipole If the antenna is arranged as “0” and the antenna is not arranged as “1”, the configuration of (a) is [000000], the configuration of (b) is [010100], and the configuration of (c). Represents [101010], respectively. 6 bits = an example of three numbers out of 64 numbers, indicating that they can be identified in this way.

An information medium using a dipole antenna according to the present invention will be described.
The information medium of the present invention includes a plurality of dipole antennas having different resonance frequencies in a frequency region above the UHF band.
For example, a dipole antenna having a resonance frequency in the UHF band can detect 1 bit information of “0” or “1” by detecting the presence or absence of the dipole antenna using the resonance frequency of the dipole antenna. It is possible to carry. When the antenna length of the dipole antenna is changed, the resonance frequency changes according to the equation (1). Therefore, by forming a plurality of dipole antennas having different resonance frequencies, it is possible to obtain an information medium having information of several bits or more corresponding to the number to be formed.

Since the antenna length L (m) of the dipole antenna is given by the equation (1), for example, assuming that the resonance frequency f ₀ is 10 GHz in the SHF band and the effective relative dielectric constant E _eff is 1, C is the speed of light Therefore, L≈1 cm from Expression (1). At 3 GHz which is the upper limit of the UHF band, it is about 3 cm. This is a case where the dipole antenna is a straight line. However, when the dipole antenna is rounded into an arc shape, the diameter is about 1 cm with a diameter of 1 / π (π: pi).

Next, two embodiments having different dipole antenna shapes will be described.
<First embodiment>
A first embodiment of an information medium using the dipole antenna of the present invention will be described.
As shown in FIG. 1, the first embodiment of the present invention is an embodiment in which the dipole antenna 2 constituting the information medium 1 has a strip shape. Further, the strips have different lengths and the same width, and the center positions of the strips in the longitudinal direction are arranged in a straight line, at equal intervals, and in parallel in the direction perpendicular to the longitudinal direction of the strips. Yes. In addition, a strip-shaped hollow portion is provided symmetrically from the longitudinal center of the strip shape.

  FIG. 1A shows a total of seven dipole antennas 2 centered on the longest dipole antenna, and each dipole antenna is sequentially directed outward on both sides in a direction perpendicular to the longitudinal direction of the dipole antenna 2. A configuration in which the centers of 2 are arranged on a straight line and three long to short ones are arranged is illustrated. The seven dipole antennas 2 having different resonance frequencies can carry 7-bit information. In the case of FIG. 1A, the state in which all the dipole antennas 2 are aligned can be displayed as [0000000]. The opposite of [1111111] may be used. The state where the dipole antenna 2 is present and the state where the dipole antenna 2 is not present may be determined to be ‘0’ or ‘1’.

  FIG. 1B can be expressed as [0100000] from the state of FIG. 1A because the dipole antenna 2 having a length of L3 is not present.

In addition, FIG. 1C can be expressed as [0000010] because the dipole antenna 2 having the length of L6 is not provided.

Thus, 7 dipole antennas 2 can carry 2 ⁷ = 128 numbers, but 128 pieces of information can be identified so that three pieces of information can be identified in this way. It is. With 10 bits, it is possible to carry 1024 numbers. With 16 bits, over 65,000 numbers can be carried. In the case of 16 bits, since 16 dipole antennas 2 are required, miniaturization of the dipole antenna 2 is an important issue in order to make the bar code the same size as conventionally used barcodes. .

  In addition, in the supermarket, in the case of a label to be attached to the displayed product, the product name, price, date of display start, displayed quantity, quantity in stock, etc. By storing the information in a computer and linking it to the number carried by the label attached to the product, it is possible not only to read the product in the basket at the cash register, but also to be sold Inventory management such as quantity and quantity in stock, number of days kept in warehouse, etc. is also possible. Similar methods of use are possible in other coatings.

<Second Embodiment>
A second embodiment of the information medium using a dipole antenna according to the present invention will be described.
The second embodiment of the present invention is an embodiment in which the dipole antenna 2 has an arc shape as shown in FIG. Furthermore, it is concentrically arranged and has an arc shape having a notch portion with the same plane angle, and the center position along the arc of the arc-shaped dipole antenna 2 is aligned with the radial direction and at equal intervals. The information medium 1 is arranged and has a hollow portion symmetrically from the center position along the arc of the dipole antenna 2.

  This embodiment has an advantage that the footprint can be reduced even when the antenna length of the dipole antenna 2 is increased by making the dipole antenna 2 into an arc shape.

  FIG. 2 exemplifies an information medium 1 composed of an arc-shaped dipole antenna 2. As the distance corresponding to the antenna length of the dipole antenna 2, the distance from the center of the circle of the arc-shaped dipole antenna 2 arranged concentrically to each arc-shaped dipole antenna is the average of the radius to the outer and inner arcs. Value. This is the radius R of each arc-shaped dipole antenna.

By doing so, even in the case of an arc-shaped dipole antenna, the radii R1 to R6 proportional to the dipole antenna lengths L1 to L6 are used instead of the dipole antenna lengths L1 to L6. It can be handled in the same manner as the strip-shaped dipole antenna shown.
FIG. 3A illustrates an information medium 1 composed of six arc-shaped dipole antennas 2. Therefore, 6-bit information can be carried, and in this case, the configuration of FIG. 3A can be displayed as [000000] as in the first embodiment.

  Similarly, the configuration of FIG. 3B can be displayed as [010100], and the configuration of FIG. 3C can be displayed as [101010]. As in the case of the first embodiment, information obtained by reversing the relationship between ‘0’ and ‘1’ may be used.

  FIGS. 3A to 3C illustrate three out of 64 types of 6-bit information, and can be identified in this way.

<Method for Manufacturing Information Medium of the Present Invention>
In the SHF band and UHF band, since the antenna length of the dipole antenna is about 1 cm (10 GHz) to 3 cm (3 GHz), various conventional printing methods such as gravure printing, planographic printing, letterpress printing, and screen are used as manufacturing methods. In addition to printing, inkjet printing, electrophotographic methods, etc., foil stamping can also be used. As the conductor ink to be used, a conductor ink using a metal powder of a grade used for manufacturing a circuit board can be used.

In the EHF band and the THF band, which are higher frequency regions, for example, the frequencies are 100 GHz and 1 THz, and the antenna length is 1 mm and 100 μm.
In this region, it is difficult to manufacture by the conventional printing method. When the antenna length is 1 mm, for example, in the case of a strip-shaped dipole antenna, the width needs to be about 1/10 or about 100 μm. Moreover, it is because the precision of a dimension and a printing shape is also requested | required. If the dimensional accuracy deteriorates, the resonance frequency cannot be obtained as intended. Similarly, in the printed shape, poor linearity and roughness of the pattern edge adversely affect the controllability of the resonance frequency.

  Thus, in the frequency region above the EHF band, it cannot be said that the pattern accuracy is sufficient with the conventional printing method. The technology that can form a fine pattern with higher accuracy than the printing method can include, for example, a photolithography technology, but it is difficult to adopt in terms of cost, so that the same fine processing as the photolithography technology is possible, Technology that can be produced at the same manufacturing cost as the printing method is required.

  In the above, the information medium which consists of chipless RFID using the dipole antenna of this invention was demonstrated. As an example, 7-bit and 6-bit information media using strip-shaped and arc-shaped dipole antennas have been described. However, the present invention is not limited to these antenna shapes. Any shape can be used as long as it functions as a dipole antenna.

  The resonance frequency of the dipole antenna is exemplified for the UHF band (300 MHz to 3 GHz) and the SHF band (3 GHz to 30 GHz), but in the future, the EHF band (30 GHz to 300 GHz) and the THF band (300 GHz), which are higher frequency regions. The frequency is increased to 3 THz). Accordingly, since the antenna length of the dipole antenna becomes finer, it is possible to provide an information medium including a chipless RFID using the dipole antenna of the present invention by adopting a manufacturing method corresponding to the antenna length. .

1 Information medium (chipless RFID)
2 ... Dipole antenna

Claims (5)

  An information medium comprising a chipless RFID including a plurality of dipole antennas having different resonance frequencies in a frequency region above the UHF band.   The information medium according to claim 1, wherein the dipole antenna has a strip shape. The dipole antennas are strips having different lengths and the same width, and the center positions in the longitudinal direction of the dipole antennas are arranged in a straight line at equal intervals in the direction perpendicular to the longitudinal direction of the dipole antennas. And
3. The information medium according to claim 2, wherein each dipole antenna has a hollow portion symmetrically from the center in the longitudinal direction.   The information medium according to claim 1, wherein the dipole antenna has an arc shape.   The dipole antenna is concentrically arranged at equal intervals, has an arc shape with notches in the same direction at the same plane angle, and is symmetrical along the arc from a position that bisects the dipole antenna. The information medium according to claim 4, further comprising a hollow portion.

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