JP2007336436A - Antenna for reader and article placing shelf with antenna and article placing table with antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna 15 for a reader which is capable of communicating with an electronic tag, substantially regardless of a direction of the electronic tag, using a comparatively small number of antennas and a comparatively simple antenna pattern 31. <P>SOLUTION: Each of a plurality of approximately loop-shaped antenna patterns 31a-31c that first and second antennas A, B comprise respectively and which are sequentially disposed approximately along with a first direction (x), is approximately configured rectangular. Each of the plurality of antenna patterns 31a-31c is linked to the adjacent other antenna pattern 31a-31c by a twist link pattern part such as a short cross pattern part 60a, 60b. The antenna patterns 31a-31c of the second antenna B are deviated in the first direction with respect to the antenna patterns 31a-31c of the first antenna A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes first and second antennas respectively provided on antenna forming target members such as a shelf plate of an article placement shelf and a base plate of an article placement table in a state of being insulated from each other and being superimposed on each other. The present invention relates to a reader antenna. The present invention also relates to an article mounting shelf with an antenna and an article mounting table with an antenna provided with a shelf board and a base board on which such an antenna for a reader is provided.

Conventionally, substantially rectangular parallelepiped articles such as documents, optical disks such as CD and DVD, other optical recording media, magnetic tapes such as video tape and audio tape, other magnetic recording media, and substantially cylindrical shapes such as bottles Various goods such as containers, irregularly shaped clothing, and various items such as various collections are displayed on the shelves, display shelves, product shelves, book shelves, document management shelves, library reception counters, etc. Are placed on an article placement table such as a counter table, a table or a desk for display, storage, management and the like. Then, the electronic tag is attached to the various articles as described above, and the various articles as described above are managed using an RFID (Radio Frequency Identification) system including a reader / writer antenna that communicates with the electronic tag. Is expected to be. Such an electronic tag is also called a wireless tag or an IC tag, and includes an IC chip in which a memory in which information is recorded is incorporated and a communication circuit including a small antenna. As described above, the reader / writer antenna that communicates with the electronic tag is a shelf plate surface on which an article is placed, or a back plate surface that is arranged on the back side of the article placement shelf for the purpose of preventing the article from dropping off. In many cases, the antenna is arranged along a loop antenna, and as illustrated in Patent Document 1, it is usually configured as a loop antenna.
JP 2004-140513 A

  On the other hand, an article with an electronic tag placed on a shelf is generally indefinite, and an electronic tag is often attached to the article itself or suspended from the article. The position and orientation of the tag are not constant. In the case of an article with a relatively constant shape, such as a book, a document binding file, or a book such as an optical or magnetic recording medium, attaching an electronic tag to a fixed position when viewed from the article is a comparison. Easy. However, even such an article is not always placed on the shelf board in a fixed position or fixed direction. Furthermore, the shelf board usually has an area where a large number of articles can be placed. Therefore, in order for the reader / writer antenna to reliably communicate with the electronic tag whose distance from the shelf surface and the orientation with respect to the shelf surface are not always constant over such a shelf plate, the reader / writer antenna is used. It is necessary to devise the antenna configuration. For example, if one reader / writer antenna is used to communicate with the electronic tag on the article side, the reader / writer antenna can be in any positional relationship so as to be perpendicular to the laying surface of the reader / writer antenna. In particular, an incommunicable area is likely to occur for a certain electronic tag.

  Thus, it is conceivable to use a plurality of reader / writer antennas. However, when a plurality of reader / writer antennas are driven by a single reader / writer, the value of the current flowing per reader / writer antenna is reduced, so that the reader / writer antenna communicates with the electronic tag. May not be able to obtain the magnetic field required. If the output of the reader / writer for driving the reader / writer antenna is increased in order to correct such drawbacks, a large driving power is required.

Conventionally, the following antenna system has been devised as an antenna system for solving the above problems. For example, in Patent Document 2, a plurality of simple loop antennas are provided as reader / writer antennas along the back plate surface (or shelf plate surface) of an article placement shelf, and at this time, the plurality of loop antennas are shared. A reader / writer antenna system is disclosed in which the plurality of loop antennas are sequentially switched and operated while being shifted by half a pitch on the back plate surface (or shelf plate surface). Further, in Patent Document 3, a plurality of loop antennas, each of which has a saw-shaped bent portion, are arranged as a reader / writer antenna so as not to completely overlap each other on a common shelf surface. In addition, a reader / writer antenna system including power supply control means for supplying power to the plurality of loop antennas so as not to overlap in time is disclosed.
JP 2003-72919 A JP 2003-168914 A

However, the conventional reader / writer antenna systems disclosed in Patent Documents 2 and 3 have problems as described in the following items (A) to (C). The reason why these problems occur is as described in the items (a) to (c), which are sequentially described after the descriptions of the items (A) to (C).
(A) When a plurality of loop antennas are arranged on a horizontally long shelf board having a certain area, even when the plurality of loop antennas are shifted from each other, a large number of loop antennas and a plurality of antennas are arranged. Switching means is required.
(A) In the case of providing a substantially rectangular loop antenna (which may be substantially circular or substantially linear) on a horizontally long substantially rectangular shelf plate that is generally used, the incommunicable area is eliminated. For this reason, it is necessary to provide a plurality of antenna groups configured by at least three loop antennas or a plurality of antenna groups configured by at least two loop antennas (in other words, four or more loop antennas). Further, in order to switch the plurality of loop antennas, the same number of antenna switching means are required.
(B) When three or more loop antennas are arranged on a common shelf surface, the position of the antenna switching means is limited because the installation position of the antenna switching means affects the performance of the reader / writer antenna system. Arise.
(B) If the length of the connecting line connecting the antenna switching means and each of the plurality of loop antennas arranged on the common shelf surface is different for each of the plurality of loop antennas, Since the communication performance changes for each loop antenna, there is a difference in communication performance among a plurality of loop antennas arranged on a common shelf surface. In particular, when a large number of loop antennas are provided on a horizontally long shelf surface, the length of the connection line between the loop antenna near the left end of the shelf and the loop antenna near the right end of the shelf. In order to make the lengths of the connecting lines substantially the same without extremely different from each other, it is necessary to provide a switching means at an intermediate position in the front direction of the back plate arranged on the back side of the article placement shelf. There is.
(C) Even if two loop antennas each having a saw-like concavo-convex shape are arranged so that each loop antenna intersects with the electronic tag so as to partially overlap each other, the antenna pattern shape and their overlapping form Depending on the situation, there is an area where the reader / writer antenna cannot communicate with the electronic tag. Such a problem cannot be solved even when a power supply switching system that supplies power to the two loop antennas so as not to overlap in time is provided.
(C) The incommunicable region occurs in a region where the magnetic field passing through the antenna of the electronic tag is weakened. Examples of the region in which the magnetic field is weakened include a case where the electronic tag is positioned in parallel with the direction of the magnetic field, and a case where a magnetic field having the same or almost the same magnitude in the reverse direction is applied from both sides of the electronic tag.
JP 2003-72919 A JP 2003-168914 A

  The present invention was invented to solve the above-described problems, and can communicate with an electronic tag substantially independently of the orientation of the electronic tag provided on the article. It is an object of the present invention to provide a reader antenna, an article mounting shelf with an antenna, and an article mounting table with an antenna, each of which includes a shelf plate and a base plate provided with such a reader antenna.

  The present invention relates to a reader antenna including first and second antennas that are formed on an antenna formation target member in a state where they are insulated from each other and overlapped with each other. Each of the first and second antennas has a plurality of substantially loops that are sequentially arranged substantially along a first direction (for example, a length direction that is a frontage direction of a shelf board, a base plate, etc.). Each of the plurality of substantially loop-shaped antenna patterns has a second direction (for example, a shelf board, a base plate, etc.) orthogonal to the first direction of the antenna forming target member. A first pattern portion provided on the first side in the width direction that is the depth direction), a second pattern portion provided on the first side in the first direction of the antenna forming target member; A third pattern portion provided on a second side of the antenna forming target member opposite to the first side in the second direction; and the antenna forming target member in the first direction. First It is configured roughly rectangular shape and a fourth pattern portion provided on the second side of the side opposite to the side. Each of the plurality of substantially loop-shaped antenna patterns is coupled to another substantially loop-shaped antenna pattern adjacent thereto by a twist coupling pattern portion. Further, the second pattern portion or the fourth pattern portion of the first antenna includes a second pattern portion corresponding to the second antenna portion and a fourth pattern portion corresponding to the second pattern portion. It is arranged between.

  In the present invention, the length of the antenna formation target member in the first direction is greater than or substantially the same as the length of the antenna formation target member in the second direction. Is preferred. Further, in the present invention, the entire antenna pattern composed of the plurality of substantially loop-shaped antenna patterns of the second antenna is the whole composed of the plurality of substantially loop-shaped antenna patterns of the first antenna. It is preferable that the antenna pattern has substantially the same or similar antenna pattern shape. Furthermore, in the present invention, each of the plurality of substantially loop-shaped antenna patterns of the first and second antennas has substantially the same and / or similar antenna pattern shape. preferable. Furthermore, in the main text, “approximately extending... Extends” even if it extends with an inclination angle within 15%, preferably within 10%, more preferably within 5%. Means good. Further, in the text, “substantially” preferably means “almost”.

  In the present invention, the twist connecting pattern portion may be one type or a plurality of types selected from a twist intersecting portion and a twist overlapping portion. In the present invention, the twist coupling pattern portion may be one or more types selected from a short cross pattern portion, a short overlapping portion, and a long cross pattern portion. Further, in the present invention, the twist coupling pattern portion is composed of a short cross pattern portion, and each of the plurality of substantially loop-shaped antenna patterns has the short cross pattern at an intermediate portion in the second direction. It may be connected to another substantially loop-shaped antenna pattern adjacent thereto by a portion. Further, in the present invention, the torsional connection pattern portion may be configured such that either one of the first and third pattern portions extending substantially along the first direction is adjacent to the other one. Each of the plurality of substantially loop-shaped antenna patterns consists of another substantially loop-shaped adjacent to each other by the short overlap portion. It may be connected to the antenna pattern. Further, in the present invention, the torsional coupling pattern portion includes the second and fourth pattern portions extending approximately along the second direction of each of the plurality of substantially loop-shaped antenna patterns. And the other of the second and fourth pattern portions extending approximately along the second direction of each of the other substantially loop-shaped antenna patterns adjacent thereto. Each of the plurality of substantially loop-shaped antenna patterns may be connected to another substantially loop-shaped antenna pattern adjacent thereto by the long cross-pattern portion.

  In the present invention, the second antenna has an average length of 0.15 to 0.35 (more preferably 0.2 to 0.3) per one first pattern portion. It is preferable that the first antenna is displaced in the first direction by the range of. In this case, the second antenna has an average length of 0.08 to 0.75 (preferably 0.1 to 0.7, more preferably, per one of the first pattern portions. The range of 0.15 to 0.6) may be shifted in the second direction with respect to the first antenna.

  Further, the present invention can be configured to supply power to only one of the first and second antennas. In another embodiment of the present invention, the first and second antennas may be alternately fed. Further, in the present invention, it is preferable that the reader antenna is configured as a reader / writer antenna.

  Further, in the present invention, the antenna formation target member is a shelf plate of an article placement shelf or a base plate of an article placement table, and a main component of the shelf plate or the base plate is a transparent non-conductor. Can be. In the present invention, at least the antenna patterns (preferably the antenna pattern and the pair of terminal portions) of the first and second antennas are each composed of a wire conductor having a cross-sectional diameter of 0.5 mm or less. it can. In the present invention, the first and second antennas may be provided between a pair of glass plates stacked on each other with an insulating layer interposed therebetween. Furthermore, in the present invention, each of the terminal portion of the first antenna and the terminal portion of the second antenna has a length direction (for example, a shelf plate or a base plate) of the antenna forming target member (for example, a shelf plate or a base plate). It may be provided on any one edge selected from one and the other edges in the frontage direction) and a back-side edge in the width direction (for example, the depth direction).

  The present invention also relates to an article mounting shelf with an antenna provided with a shelf plate on which the above-described reader antenna according to the present invention is formed as the antenna formation target member. The present invention also relates to an article mounting table with an antenna provided with the base plate on which the above-described reader antenna according to the present invention is formed as the antenna formation target member.

  According to the first to seventh aspects of the present invention, the incommunicable region extending along the second direction of each of the first and second antennas has a relatively small number of antennas (that is, two antennas). In addition, the antenna patterns can be complemented by a relatively simple antenna pattern shape. For this reason, it is possible to provide a reader antenna that is capable of good communication with the electronic tag regardless of the direction of the electronic tag.

  According to the invention of claim 7, the induced current generated in the antenna portion extending in the first direction of the other antenna by the loop current flowing through one of the first or second antennas is The other antenna can be made to flow in one direction as much as possible.

  According to the invention according to claim 8, by supplying power only to one of the first and second antennas, an induced current is generated in the other antenna by the magnetic field generated by the one antenna. To do. For this reason, since this induced current generates a magnetic field so as to supplement the magnetic field generated from the one antenna, there is no need for an antenna switching means for alternately supplying power to the first and second antennas. Communication speed can be shortened.

  Further, as in the invention according to claim 8, when one of the first and second antennas is fed, the magnetic field generated by the induced current generated in the other antenna is the one antenna. Is slightly smaller than the magnetic field generated by. However, according to the invention according to claim 9, by alternately feeding power to the first and second antennas, the overall magnetic field strength generated from both antennas can be made uniform. A stable communication state between the electronic tag and the reader antenna can be ensured only by providing the antenna switching means.

  According to the invention of claim 10, since it is possible to perform both writing to the electronic tag and reading from the electronic tag with a common antenna, the configuration of the entire reader / writer can be simplified. .

  Moreover, according to the invention which concerns on Claim 11, when the said shelf board of the article mounting shelf provided with the multistage shelf board is used as an antenna formation object member, another one is passed through one or more shelf boards. Since it is easy to see the articles on the shelf board, it is easy to handle the articles on this other shelf board, and the lighting equipment for the article storage shelf is omitted or reduced in scale. Can do.

  According to the invention of claim 12, since the first and second antennas are provided between a pair of glass plates each having excellent weather resistance and chemical resistance, the reader antenna is used in various environments. Even if it protects effectively. For this reason, since the weather resistance and chemical resistance of the reader antenna are improved, there is no risk of damage even if the reader antenna is provided on a chemical shelf or the like.

  According to the invention of claim 13, since it is easy to collect the terminal portions for feeding the first and second antennas in one place, restrictions on the installation position of the antenna switching means are reduced. be able to.

  Furthermore, according to the invention which concerns on Claim 14 and 15, it is substantially in the direction of the electronic tag provided in the articles | goods mounted on the shelf board of an article mounting shelf, and the base plate of an article mounting base. Irrespective of the above, it is possible to provide an article placement shelf and an article placement table provided with a reader antenna capable of communicating with the electronic tag.

  Next, the first and second embodiments, in which the present invention is applied to the article placement shelf, are divided into "1, first embodiment" and "2, second embodiment", respectively. Will be described with reference to FIG.

1. First Example Firstly, according to a first example of the present invention, “(1) Overall configuration of article placement shelf”, “(2) Basic unit pattern shape of reader / writer antenna”, “ The description will be divided into “(3) Specific pattern shape of reader / writer antenna” and “(4) Feeding method to reader / writer antenna” with reference to FIGS.

(1) Overall Configuration of Article Placement Shelf As shown in FIG. 1, the article placement shelf 1 according to the first embodiment of the present invention faces the left side plate 2, the right side plate 3, and the back plate. 4. It has a substantially box-lid shape (in other words, a substantially rectangular parallelepiped shape) composed of the top plate 5 and the bottom plate 6. The pair of left and right side plates 2, 3, the back plate 4, the top plate 5 and the bottom plate 6 can be made of appropriate materials such as glass, synthetic resin, wood, etc., and the bottom plate 6 is the bottom shelf plate. Is also used. The article mounting shelf 1 may further include a front plate (not shown) that is preferably made of glass, synthetic resin, or the like so as to be substantially transparent. It may be a sliding door structure. One or more or all of the pair of left and right side plates 2, 3, back plate 4, top plate 5, bottom plate 6 and front plate may be metal, and when a reader / writer antenna is formed on the surface thereof. May be formed after covering the surface with an insulating layer. In the illustrated embodiment, the pair of left and right side plates 2 and 3 are configured to slightly protrude downward from the bottom plate 6, and a pair of left and right support legs 7 and 8 are formed by the pair of left and right projections, respectively. ing.

  In the illustrated embodiment, the article mounting shelf 1 shown in FIG. 1 is made of an appropriate non-metallic material (in other words, a transparent or opaque non-conductor) such as glass, synthetic resin, or wood. 5, the uppermost shelf 11, the second shelf 12, the third shelf 13, the fourth shelf 14, and the lower shelf 6, respectively. It has a stage configuration. These shelves 6, 11-14 are a pair of left and right side plates 2, 3, and back plate 4 by means of appropriate support means (not shown) on the pair of left and right side edges and / or the side edge on the back plate side. Can be supported.

  Reader / writer antennas 15 shown in FIGS. 5 to 10 are installed on the shelf boards 6 and 11 to 14 of the article placement shelf 1 shown in FIG. 1 so as to be substantially parallel to the respective shelf board surfaces. Has been. The first and second antennas A and B of the reader / writer antenna 15 are connected to the antenna switch 16 by a coaxial cable (not shown) after passing through a matching adjuster (not shown). ing. The antenna switch 16 is connected to a reader / writer body (not shown) and a control computer (not shown) by a coaxial cable 17. This reader / writer main body is for exchanging information such as electrical signals with the reader / writer antenna 15. The antenna switch 16 can be disposed on the article management shelf 1 and is disposed on the top plate 5 in the illustrated embodiment. The reader / writer main body can be similarly arranged on the article mounting shelf 1 as necessary. In the present invention, the shelf boards 6 and 11 to 14 can be made of a suitable metallic material such as steel or aluminum alloy. In this case, a magnetic material sheet such as a ferrite sheet is provided between the metallic material and the reader / writer antenna 15 so that the magnetic flux canceling phenomenon due to the metallic material constituting the shelf plates 6 and 11 to 14 does not occur. (Not shown) is preferably interposed.

  Various forms of articles 18 are mixedly mounted on the respective shelf boards 6 and 11 to 14 of the article placement shelf 1 shown in FIG. 1, and these articles 18 may have an electronic tag 19 that may be in the form of a sheet. Are provided. The electronic tag 19 may be attached to the back cover, the front cover, or the back cover when the article 18 is a book 18a. In the case of an article 18b such as a box or a container other than the books, It may be attached to the side, upper surface, lower surface, or the like. In any of these cases, the electronic tag 19 does not need to be in a specific position or a specific direction with respect to the surfaces of the shelf boards 6 and 11 to 14. As shown in FIG. 2, such an electronic tag 19 has a single-turn or multiple-turn small loop-shaped antenna 21 whose center substantially coincides with the center of the electronic tag 19, and information is recorded. And a communication circuit including an IC chip 22 in which a memory (not shown) to be incorporated is incorporated and arranged in the central opening of the small loop-shaped antenna 21 may be provided.

Each shelf board 6 and 11 to 14 of the article management shelf 1 shown in FIGS. 1 and 5 to 10 has a length L ₁ in the frontage direction (see FIG. 5C) of about 900 mm and a length L ₂ in the depth direction, for example. (See FIG. 5C) may be approximately 350 mm horizontally long and approximately rectangular. As shown in FIG. 5C, a reader / writer antenna 15 including first and second antennas A and B is installed on each of the shelf boards 6 and 11-14. FIG. 5A is a plan view of, for example, the uppermost shelf 11, in which the second antenna B is omitted and only the first antenna A is projected. FIG. 5B is a plan view of, for example, the uppermost shelf 11, in which the first antenna A is omitted and only the second antenna B is projected. FIG. 5C is a plan view of, for example, the uppermost shelf 11 that projects and shows both the first and second antennas A and B. FIG. The shelf boards 6 and 12 to 14 other than the shelf board 11 may be provided with reader / writer antennas 15 having substantially the same shape as the shelf board 11 shown in FIGS. A reader / writer antenna 15 in which one or both of the second antennas A and B are different from the case of the shelf board 11 may be installed. In FIG. 5C and all similar drawings (including the case of the second embodiment described later), the first antenna A is indicated by a solid line and the second antenna B is indicated for convenience of illustration. It is indicated by a broken line. In addition, the width of each pattern portion of the antenna patterns 31 of the first and second antennas A and B is also shown to be thicker than actual for convenience of illustration. Furthermore, although the actual widths of the pattern portions of the antenna patterns 31 of the first and second antennas A and B may be substantially the same as each other, for convenience of illustration, the antenna pattern of the second antenna B The width of each pattern portion 31 is thicker than the width of each pattern portion of the antenna pattern 31 of the first antenna A.

The first and second antennas A and B of the reader / writer antenna 15 (specifically, both the substantially loop-shaped antenna pattern 31 and the pair of terminal portions 32a and 32b shown in FIGS. 5 to 10) As shown in FIG. 3, conductive wire paint (for example, silver paste) is applied to the upper and lower plates 23 and 24 made of a suitable non-metallic material such as glass, synthetic resin, and wood, for example, with a width of about 20 mm. Each may be printed and fired. The first and second antennas A and B may be made of copper wire having a substantially circular cross section and a cross sectional diameter of 0.1 mm. In this case, the copper wire may be mounted and arranged by being bent into a predetermined pattern shape and then partially or entirely bonded to the plates 23 and 24 with an appropriate adhesive. Furthermore, as described above, the pair of terminal portions 32a and 32b of the first and second antennas A and B are composed of a conductive pattern formed by printing and baking a conductive paint, and substantially As described above, the loop-shaped antenna pattern 31 may be made of a copper wire. In this case, both end portions of the antenna pattern 31 may be electrically connected to the pair of terminal portions 32a and 32b by bonding or soldering with an appropriate conductive adhesive. Next, these plates 23 and 24 are bonded using an intermediate film 25 made of a non-conductive film such as PVB resin, so that the first and second antennas A and B are two upper and lower plates 23 and 24. It is sandwiched between. These plates 23 and 24 may be glass plates having a thickness of about 5 mm, for example, and the thickness L ₃ of the intermediate film 25 may be about 300 μm, for example. The material constituting the first and second antennas A and B is not necessarily a conductive paint, and a conductive film, a conductive metal foil, a metal wire such as a copper wire as described above, and other wire conductors. It may be.

  As shown in FIG. 3, the first and second antennas A and B of the reader / writer antenna 15 configured as described above are electrically insulated from each other and are connected to the surfaces of the shelf boards 6 and 11 to 14. They are sandwiched between two glass plates 23 and 24 in a substantially parallel state (in other words, antennas A and B are substantially parallel to each other). Accordingly, the first and second antennas A and B are prevented from being scratched by contact with the article 18 disposed on the shelf boards 6 and 11 to 14. Moreover, since the glass plate which comprises the upper and lower surfaces of the shelf boards 6 and 11-14 is excellent in water resistance, weather resistance, chemical resistance, etc., the article management shelf 1 shown in FIG. 1 is used for various uses. Can be done. And when the main component of the shelf boards 6 and 11-14 is a transparent glass material, the reader / writer antenna 15 is also constituted by the thin wire conductor as described above in which the intersecting portion and the overlapping portion are insulated. You can also

In the present invention, the distance L ₃ (see FIG. 3) between the two antennas A and B that are substantially parallel to each other in the thickness direction is generally 0.1 to 70 mm from the viewpoint of practicality. It is preferable that it is the range of these. However, this spacing L ₃ is smaller than 0.1 mm, 2 pieces of antennas A, may be any possible electrical isolation between the B. Further, if the distance _{L 3} is greater than 70 mm, 2 pieces of antennas A, none of B is satisfactorily communicate with the electronic tag 19 provided in the article 18 being placed on the shelf plate 6,11～14 There is a risk of difficulty.

  In the illustrated embodiment, the first and second antennas A and B of the reader / writer antenna 15 are embedded in the shelves 6 and 11 to 14 as shown in FIG. However, at least one of the first and second antennas A and B may be similarly formed on the upper surfaces of the shelf boards 6 and 11 to 14. Moreover, the at least one antenna can be formed on the lower surface of each shelf board 6, 11 to 14 by turning the shelf boards 6, 11 to 14 upside down. Further, one of the first and second antennas A and B can be formed on the upper surface of each shelf plate 6, 11 to 14, and the other can be formed on the lower surface of each shelf plate 6, 11 to 14. . In any of these cases, the intermediate film 25 is omitted when the plates 23 and 24 which are the main components of the shelf boards 6 and 11 to 14 are interposed between the first and second antennas A and B. Can do. Moreover, when these antennas A and B are formed on the upper surface and / or the lower surface of each shelf plate 6, 11 to 14, the chance of contacting the article 18 disposed on each shelf plate 6, 11 to 14 is reduced. Therefore, the upper surface and / or the lower surface of each shelf plate 6, 11-14 including the at least one antenna can be coated with a coating film made of a suitable insulating material.

(2) Basic unit pattern shape of reader / writer antenna As shown in FIG. 5C, the reader antenna 15 for communicating with the electronic tag 19 provided on the article 18 by wireless communication is the first antenna A. It consists of a second antenna B. As shown in FIGS. 5A and 5B, each of the first and second antennas A and B is a pair of antenna pattern 31 and a pair of antenna patterns 31 that are connected to both ends of the antenna pattern 31 and are close to each other. Terminal portions 32a and 32b. Since the gap 33 is provided between the pair of terminal portions 32 a and 32 b, the gap 33 similarly exists between both end portions of the antenna pattern 31. The pair of terminal portions 32a and 32b may be connected to the matching adjuster (not shown) by the twist cable (not shown).

  A basic unit pattern shape C of the first and second antennas A and B constituting the reader / writer antenna 15 shown in FIG. 5C is shown in FIG. 4A. This basic unit pattern shape C is the first antenna shown in FIGS. 5A and 5C, except that the pattern shapes of FIGS. 5A and 5C are partially omitted for clarity of illustration. It is substantially the same as the pattern shape of A. As shown in FIG. 4A, the basic unit pattern shape C antenna pattern 31 includes a first substantially loop-shaped antenna pattern 31a, a second substantially loop-shaped antenna pattern 31b, and a third substantially loop-shaped antenna pattern. Antenna pattern 31c and a fourth substantially loop-shaped antenna pattern 31d. And each of these 1st-4th antenna patterns 31a-31d is comprised by the substantially rectangular shape, and is arrange | positioned sequentially from the left side to the right side along the opening direction x of the shelf board 11. FIG. Therefore, the basic unit pattern shape C is also formed in a substantially rectangular shape as a whole.

  As shown in FIG. 4A, the leftmost antenna pattern 31a is connected to the rightmost antenna pattern 31b by a short cross pattern portion 61a in the middle portion in the depth direction y. The rightmost antenna pattern 31d is connected to the antenna pattern 31c on the right side by a short cross pattern portion 61c at an intermediate portion in the depth direction y. The antenna patterns 31b and 31c existing between the leftmost antenna pattern 31a and the rightmost antenna pattern 31d are shorter than the leftmost antenna patterns 31a and 31b in the middle portion in the depth direction y. While being connected by the cross pattern portions 61a and 61b, respectively, the antenna patterns 31c and 31d on the right side thereof are respectively connected by short cross pattern portions 61b and 61c in the middle portion in the depth direction y. It should be noted that the cross pattern portions 61a to 61c naturally have intersection portions 60a to 60c, respectively. A pair of terminal portions 32a and 32b are connected to both end portions on the terminal side of the fourth antenna pattern 31d. In the text, the above-mentioned “intersection” and “overlap” described later are electrically connected intersections and do not overlap, but in a projection view of the antenna forming target member such as the shelf board 11 (in other words, This means that they intersect and overlap each other (in plan view). Therefore, it can be said that the antenna pattern 31 shown in FIG. 4A is a substantially loop-shaped antenna pattern having a plurality of intersecting portions 60a to 60c as a whole.

As shown in FIG. 4A, the antenna pattern 31 of the basic unit pattern shape C configured as described above includes pattern portions described in the following items (A) to (F).
(A) The first to first portions are intermittently extended so that an intermittent portion 42a is generated between them in a state of being close to and substantially parallel to the rear edge portion 34 of the shelf board 11. A plurality of first pattern portions (in other words, baseline portions) 43a for the fourth antenna patterns 31a to 31d;
(A) A state in which the shelf 11 is close to the left edge 36 and substantially parallel to the left edge 36 (in other words, a state substantially parallel to the depth direction y of the shelf 11, In this embodiment, the second pattern portion 37 extending substantially linearly),
(C) The first to the second plates are intermittently extended so that the intermittent portion 42b is formed between them in a state of being close to the front edge portion 38 of the shelf board 11 and substantially parallel to the front edge portion 38. A plurality of third pattern portions (in other words, baseline portions) 43b for the fourth antenna patterns 31a to 31d;
(D) The first and the first rising substantially along the depth direction y from the end portions of these baseline portions 43a and 43b to the cross pattern portions 60a to 60c (in other words, near the shelf centerline 45). Second rising portions 46, 47,
(E) One or plural (preferably plural) short cross pattern portions 60a to 60c as connecting pattern portions, and (f) the right side edge portion 40 in the vicinity of the shelf board 11 and this left side. A fourth extending in a state substantially parallel to the edge 36 (in other words, substantially parallel to the depth direction y of the shelf board 11 and substantially straight in the illustrated embodiment). Pattern portion 41.

  The plurality of baseline portions 43a constitute the first pattern portion 35 of the antenna pattern 31. Further, the third pattern portion 39 of the antenna pattern 31 is configured by the plurality of baseline portions 43b. Further, as shown in FIG. 4A, the antenna pattern 31 of the basic unit pattern shape C has one or more (in other words, intermittent portions 42a) between one or a plurality of baseline portions 43a (in other words, intermittent portions 42a). Preferably, one or a plurality of (preferably a plurality of) bent portions exist between a plurality of bent portions 44a and a plurality of baseline portions 43b (in other words, intermittent portion 42B). 44b. The bent portion 44a is bent in a substantially rectangular shape so as to protrude from the rear edge portion 34 side to the front edge portion 38 side of the shelf board 11, and the first and second rising portions 46, 47 are bent. And a half portion of the cross pattern portions 61a to 61c on the rear edge portion 34 side (that is, a substantially mountain shape or a substantially square shape portion having the intersection portions 60a to 60c as apexes). The bent portion 44b is bent in a substantially rectangular shape so as to protrude from the front edge portion 38 side to the rear edge portion 34 side of the shelf board 11, and the first and second rising portions 46, 47 are bent. And the other half of the cross pattern portions 61a to 61c on the front edge portion 38 side (that is, a substantially mountain shape or a substantially square shape portion having the intersection portions 60a to 60c as vertices).

  In the basic unit pattern shape C shown in FIG. 4A, the intersecting portions 60 a to 60 c of the cross pattern portions 61 a to 61 c are substantially on the shelf centerline 45. Further, the distance between the plurality of baseline portions 43a and the shelf center line 45 in the depth direction y is substantially the same as the distance between the plurality of baseline portions 43b and the shelf center line 45 in the depth direction y. is there. Therefore, the shelf center line 45 also serves as a virtual center line extending in the frontage direction x of the basic unit pattern shape C. The antenna patterns 31a, 31b are formed by the first rising portion 46 on the rear edge portion 34 side of the substantially loop-shaped antenna patterns 31a, 31b, 31c and the first rising portion 46 on the front edge portion 38 side. , 31c, fourth pattern portions 41a, 41b, and 41c are formed. The antenna patterns 31b, 31c are formed by the second rising portion 47 on the rear edge portion 34 side of the substantially loop-shaped antenna patterns 31b, 31c, 31d and the second rising portion 47 on the front edge portion 38 side. , 31d second pattern portions 37b, 37c, 37d are respectively configured. And these 4th and 2nd pattern parts 41a-41c, 37b-37d are interrupted in short cross pattern part 60a, 60b, 60c, and have the discontinuous part 59. FIG. Therefore, the first rising portion 46 is a component of the fourth pattern portions 41a to 41c of the antenna patterns 31a to 31c. The second rising portion 47 is a component of the second pattern portions 37b to 37d of the antenna patterns 31b to 31d. The second pattern portion 37 of the antenna pattern 31 also serves as the second pattern portion of the substantially loop-shaped antenna pattern 31a. The fourth pattern portion 41 of the antenna pattern 31 also serves as the fourth pattern portion of the substantially loop-shaped antenna pattern 31d.

  From a different viewpoint, the antenna pattern 31 of the basic unit pattern shape C shown in FIG. 4A has a large loop antenna pattern (not shown) that has neither intersection nor overlap for forming the antenna pattern 31. ) At one or more suitable locations, one or more twisted intersections (i.e., short cross-pattern portions, in other words, twisted connecting portions) 60a-60c are connected to the large loop. It can be said that the antenna pattern is formed. In this case, specifically, the third substantially loop-shaped antenna pattern 31c includes one baseline portion (that is, the first pattern portion) 43a and the other baseline portion (that is, the third pattern portion). It can be said that the second and fourth substantially loop-shaped antenna patterns 31b and 31d are respectively half-twisted (that is, twisted by 180 °) so that 43b is interchanged. Further, the first substantially loop-shaped antenna pattern 31a is configured such that one baseline portion (ie, the first pattern portion) 43a and the other baseline portion (ie, the third pattern portion) 43b are interchanged with each other. Furthermore, it can be said that the portion on the right edge 40 side in the frontage direction x is half twisted with respect to the second substantially loop-shaped antenna pattern 31b. The above replacement can be achieved by twisting 1.5 times, twisting 2.5 times, and the like. In the text, “twisted connection pattern portion” or “twisted connection portion” means connection pattern portions 60a to 60c or a connection portion generated by the above-described replacement by twisting. Accordingly, the short cross pattern portions 60a to 60c constitute a twist connection pattern portion and a twist connection portion, respectively.

One feature of the basic unit pattern shape C shown in FIG. 4A is the direction of current flowing in each longitudinal pattern portion of the antenna pattern 31 when a loop current is passed through the basic unit pattern shape C. For example, when a loop current flows through the basic unit pattern shape C from the terminal portion 32a of the pair of terminal portions 32a and 32b toward the terminal portion 32b as shown by the solid line arrows in FIG. As is apparent when referring to the solid-line arrows in FIG. 7B, the currents in the directions described in the following items (a) and (b) flow in each longitudinal pattern portion of the pattern 31.
(A) A current flows alternately in the opposite direction in the longitudinal pattern portion (that is, the four baseline portions 43a and the four baseline portions 44b) extending substantially in the frontage direction x (in other words, On the right edge 40 side, the baseline portions 43a of the first and third substantially loop-shaped antenna patterns 31a and 31c and the baseline portions 43b of the second and fourth substantially-loop shaped antenna patterns 31b and 31d Current flows from the left side edge 36 toward the left side edge 36, and the base line portion 43a of the second and fourth substantially loop-shaped antenna patterns 31b and 31d and the first and third substantially loop-shaped antenna patterns 31a and 31c. In the baseline portion 43b, a current flows from the left edge portion 36 side toward the right edge portion 40 side), and (b) depth. Longitudinal pattern portions extending substantially in the direction y (ie, the second and fourth pattern portions 37, 41 and the first and second rising portions 46 of the three bent portions 44a and the three bent portions 44b, 47) that current flows alternately in the opposite direction (in other words, the second and fourth pattern portions 37 and 41, the second substantially loop-shaped antenna pattern 31b, and the third substantially loop-shaped antenna). In the first and second rising portions 46 and 47 of the bent portions 44a and 44b between the pattern 31c, current flows from the rear edge portion 34 side to the front edge portion 38 side, and the first substantially loop shape Between the second antenna pattern 31a and the second substantially loop-shaped antenna pattern 31b, and the third substantially loop-shaped antenna pattern 31c and the fourth substantially loop-shaped antenna pattern. The bent portion 44a between 1d, the first and second rising portions 46 and 47 of 44b, a current flows through the trailing edge 34 side from the front edge portion 38 side).

Another feature of the basic unit pattern shape C shown in FIG. 4A is that the magnetic field component in the frontage direction x parallel to the surface of the shelf 11 changes substantially periodically according to the position along the frontage direction x. 4B, there is a tendency to become weak in the hatched region 49. In FIG. This is because the magnetic field components in the frontage direction x generated by the antenna portions extending in the depth direction y (that is, the second and fourth pattern portions 37 and 41 and the first and second rising portions 46 and 47) are This is because it becomes smaller at an intermediate position between adjacent antenna portions. Therefore, in the basic unit pattern shape C shown in FIG. 4A alone, the hatched region 49 is in a state where the electronic tag 19 (see FIG. 2) is parallel to the yz plane (z is a direction perpendicular to the surface of the shelf 11). In other words, the reader / writer antenna 15 (in other words, the basic unit pattern shape C shown in FIG. 4A) may not be able to communicate with the electronic tag 19. The electronic tag 19 shown in FIG. 2 may have, for example, a horizontal length L ₆ of 85.6 mm and a vertical length L ₇ of 54 mm.

As described above, the reader / writer antenna 15 shown in FIG. 5C communicates with the electronic tag 19 placed parallel to the yz plane. The component in the direction x has an influence. Therefore, the antenna portion extending substantially the depth direction y of the antenna 15 is preferably extends substantially perpendicular to the frontage direction x, somewhat may have a tilt angle theta _1. In the present invention, this inclination angle θ ₁ is generally preferably in the range of 0 ° to 15 °, more preferably in the range of 0 ° to 10 °, from the viewpoint of practicality. The range of 0 ° to 5 ° is more preferable. Therefore, it can be said that each of the second and fourth pattern portions 37 and 41 and the first and second rising portions 46 and 47 extends substantially along the depth direction y. Of the antenna portions extending in the depth direction y (that is, the second and fourth pattern portions 37 and 41 and the first and second rising portions 46 and 47), the adjacent antenna portions are y−. The width of the front end direction x of the basic unit pattern shape C with respect to the electronic tag 19 placed parallel to the z-plane is substantially parallel to each other so that the width in the frontage direction x is as constant as possible along the depth direction y. Is preferred.

4B shows a region 49 where the magnetic field component in the frontage direction x parallel to the surface of the shelf 11 for the basic unit pattern shape C shown in FIG. 4A is weakened, whereas FIG. A region 50 in which the magnetic field component in the depth direction y parallel to the surface of the shelf 11 for the basic unit pattern shape C shown is weakened. And the magnetic field component of the depth direction y parallel to the surface of the shelf board 11 also tends to become weak in the hatched area 50 in FIG. 4C for the same reason as in the case of the frontage direction x described above. Therefore, the antenna portions (that is, the first and second baseline portions 43a and 43b) extending in the frontage direction x in the basic unit pattern shape C correspond to the electronic tag 19 placed parallel to the xz plane. It is preferable that the width in the depth direction y of the incommunicable region of the basic unit pattern shape C is substantially parallel to each other so as to be as constant as possible along the frontage direction x. However, the antenna portion 43a, 43b is not necessarily required to be substantially parallel to each other, they may be inclined to each other to the same extent as if the inclination angle theta _1.

(3) Specific Pattern Shape of Reader / Writer Antenna The reader / writer antenna 15 shown in FIG. 5C has an antenna pattern shape 31 and / or substantially the same as the basic unit pattern shape C described in the above section (2). The first and second antennas A and B each having a similar antenna pattern shape 31 are combined and arranged. Then, the first and second antennas are arranged so that the respective chain line regions 49 in which the magnetic field components in the frontage direction x of the first and second antennas A and B are weakly arranged without overlapping each other. A and B are arranged, respectively.

  In the reader / writer antenna 15 shown in FIG. 5C, one of the first to fourth antenna patterns 31a to 31d is omitted for the sake of clarity in comparison with the basic unit pattern shape C shown in FIG. 4A. The first antenna A shown in FIG. 5A is combined with the second antenna B shown in FIG. 5B similar to the first antenna A shown in FIG. 5A. Note that the first and second antennas A and B have one of the first to fourth antenna patterns 31a to 31d made clearer than the basic unit pattern shape C shown in FIG. 4A. Each has a pattern shape omitted. Therefore, as shown in FIGS. 5A and 5B, the first antenna A has hatched areas similar to the hatched areas 49 and 50 of the basic unit pattern shape C shown in FIGS. 4B and 4C. Further, the second antenna B has a substantially loop-shaped antenna pattern 31 that is substantially the same as that of the first antenna A, and only the positions of the pair of terminal portions 32a and 32b of the shelf board 11 are present. It differs from the first antenna A shown in FIG. 5A only in that it is changed from the rear edge portion 34 side to the front edge portion 38 side. For this reason, as shown in FIG. 5B, the second antenna B also has a hatched area 49b that is substantially the same as the hatched area 49a of the first antenna A shown in FIG. 5A. Therefore, the first antenna A and the second antenna B have substantially the same pattern shape (that is, the antenna pattern 31).

The reader / writer antenna 15 is configured by arranging the first and second antennas A and B in combination with each other as shown in FIG. 5C. In this combination, as shown in FIG. 5C, the second antenna B is approximately 2/3 of the distance L ₄ (see FIG. 5A) in the frontage direction x with respect to the first antenna A (ie, approximately 0. a 67L _4, in the illustrated embodiment, while being arranged with a shift to the left by about 100 mm), are arranged in a state that does not deviate in the depth direction y. Accordingly, the above description of the basic unit pattern shape C applies not only to the first antenna A, but also to the second antenna B, except for changes caused by the difference between the two. The same applies except for changes that occur when the positions of the pair of terminal portions 32a and 32b are different. And the 1st antenna A and the 2nd antenna B have the longitudinal overlapping part 62-71 which mutually overlaps in the up-down direction z, as shown to FIG. 5C. Further, when the second antenna B is shifted in the frontage direction x with respect to the first antenna A, the reader / writer antenna 15 is substantially equivalent in performance regardless of whether it is shifted leftward or rightward.

In the case of the reader / writer antenna 15 shown in FIG. 5C, the hatched area 49a in the frontage direction x for the first antenna A and the hatched area 49b in the frontage direction x for the second antenna B are shown in FIG. As shown, they are staggered at approximately equal intervals (in other words, approximately 0.5 L ₄ intervals). FIG. 6B shows a first modification of the reader / writer antenna 15 shown in FIG. 5C. In the reader / writer antenna 15 shown in FIG. 6B, the distance at which the second antenna B is shifted to the left with respect to the first antenna A is approximately 0.25 L ₄ (in the illustrated embodiment, about 37.5 mm). The configuration is substantially the same as that of the reader / writer antenna 15 shown in FIG. 6A. In this case, the hatched area 49a and the hatched area 49b are staggered as shown in FIG. 6B, but the distance between them is almost equal.

  In the case of the reader / writer antenna 15 shown in FIGS. 6A and 6B, the diagonally shaded region 49a or 49b having a weak magnetic field component in the frontage direction x by one of the first and second antennas A and B is Supplemented by the antenna. Therefore, there is substantially no region where the reader / writer antenna 15 cannot communicate with the electronic tag 19 parallel to the yz plane. In the case of the reader / writer antenna 15 shown in FIG. 6C as Reference Example 1 of the reader / writer antenna 15 shown in FIG. 5C, the antenna pattern 31 of the first antenna A and the antenna pattern 31 of the second antenna B are shown. And almost completely overlap each other. Therefore, in the case of the reader / writer antenna 15 shown in FIG. 6C, the incommunicable areas 49a and 49b similar to the case of the first antenna A and the second antenna B shown in FIGS. 5A and 5B are provided. Exist.

  In one aspect of the present invention, a magnetic field generated when power is supplied to one of the first and second antennas A and B, and the value of the induced current generated in the other antenna is increased. Is preferred. For this reason, the direction of the induced current of the entire first antenna A or the entire second antenna B is such that most of the longitudinal overlapping portions 62 to 71 of the first and second antennas A and B (see FIG. 5C). It is preferable to arrange the first and second antennas A and B so as to coincide with the direction of the induced current generated in most parts of the part and / or the closest longitudinal proximity part.

  For example, in the case of the reader / writer antenna 15 shown in FIG. 5C, when the first antenna A is fed in the direction of the solid arrow in FIG. 7A (or the opposite direction), the first and second antennas are supplied. The induced current generated in the second antenna B in the longitudinal overlapping portions 62 to 71 of A and B is the direction of the broken arrow that is opposite to the direction of the solid arrow in FIG. 7A (or the opposite direction). (Or vice versa). However, in this case, the second and fourth pattern portions 37 and 41 of the second antenna B and the first and second rising portions 46 and 47 are respectively connected to the second and fourth patterns of the first antenna A. Since the pattern portions 37 and 41 and the corresponding portions of the first and second rising portions 46 and 47 are not particularly overlapped and / or not close to each other, the second antenna B is guided at these corresponding portions. Is hard to get up. The direction of the induced current in the longitudinal overlapping portions 63, 65, 68, 70 of the second antenna B is the direction of the induced current in the longitudinal overlapping portions 62, 64, 67, 69 of the second antenna B. Is the opposite. Therefore, it can be said that the direction in which the induced current flows in the second antenna B is indefinite.

  On the other hand, in the case of the reader / writer antenna 15 shown in FIG. 6B, the antenna portions extending in the depth direction y of the second antenna B (that is, the second and fourth pattern portions 37 and 41 and the first antenna portion 1). The direction of the induced current generated in the second rising portions 46, 47) is such that the antenna portion of the first antenna A is close to and substantially parallel to the antenna portions 37, 41, 46, 47 of the second antenna B. In response to guidance from (that is, the second and fourth pattern portions 37 and 41 and the first and second rising portions 46 and 47), the directions are indicated by broken arrows in FIG. 7B. The direction indicated by the dashed arrow in FIG. 7B is different from the direction indicated by the dashed arrow of the induced current in the longitudinal overlapping portions 62 to 71 shown in FIG. It matches the direction of the current. 7C shows a modified example of the reader / writer antenna 15 shown in FIG. 5C, in which the way of shifting the first and second antennas A and B in the frontage direction x is opposite to that in FIG. 7B. It is shown as 2. Also in the case shown in FIG. 7C, the direction indicated by the dashed arrow of the induced current is substantially the same as in FIG. 7B. Therefore, in the cases of FIGS. 7B and 7C, the direction of the induced current of the second antenna B as a whole can be constant and can be intensified, so that the induced current is preferable to that of FIG. 7A.

Further, the reader / writer antenna 15 shown in FIG. 8 is a modification 3 of the reader / writer antenna 15 shown in FIG. 5C. In the reader / writer antenna 15 shown in FIG. On the other hand, the second antenna B is shifted in the depth direction y by approximately 1/6 of the distance L ₅ (that is, approximately 0.17L ₆ and approximately 30 mm in the illustrated embodiment). Yes. In this case, since the longitudinal overlapping portions 62 to 71 in FIG. 5C are changed to the longitudinal proximity portions 62 to 71 as shown in FIG. 8, As shown in FIG. 9A, the hatched regions 49a and 49b having weak magnetic field components can be prevented from overlapping each other, and the magnetic field components in the depth direction y for the first and second antennas A and B are weak. The hatched areas 50 can be prevented from overlapping each other. Therefore, the diagonally shaded area 50 having a weak magnetic field component in the depth direction y for one of the first and second antennas A and B is supplemented by the other antenna. However, in this case, since the direction of the induced current in the longitudinal proximity portions 62 to 71 is as shown by the dashed arrow as shown in FIG. 10A, the direction of the induced current of the second antenna B as a whole is As in the case of FIG. 7A, it is indefinite. 9B and 10B show a fourth modification of the reader / writer antenna 15 shown in FIG. 5C. The reader / writer antenna 15 shown in FIG. 9B and FIG. 10B is an interval for shifting the second antenna B to the left side in the frontage direction x with respect to the first antenna A in the reader / writer antenna 15 shown in FIG. is almost to 0.25L ₄ a. In the case of the reader / writer antenna 15 shown in FIG. 9B as well, not only the hatched areas 49a and 49b can be prevented from overlapping each other, but also the hatched areas 50 can be prevented from overlapping each other. The directions of the induced currents at the overlapping portions and the longitudinal adjacent portions can be made to substantially coincide with each other as shown by the dashed arrows in FIG. 10B.

  FIG. 9C shows Reference Example 2 of the reader / writer antenna 15 shown in FIG. 5C. The reader / writer antenna 15 shown in FIG. 9C is the same as the reader / writer antenna 15 shown in FIG. 8 except that all antenna portions extending in the depth direction y of the first antenna A (that is, the second and second antennas). 4 pattern portions 37, 41 and all of the first and second rising portions 46, 47) extend in the depth direction y of the second antenna B, and all the antenna portions 37, 41, 46, 47. Are overlapped with each other in the vertical direction z. Therefore, in the case of the reader / writer antenna 15 shown in FIG. 9C, most of the hatched regions 49a and 49b having weak magnetic field components in the front-facing direction x of the first and second antennas A and B overlap each other. . Further, as a modification example 5 of the reader / writer antenna 15 shown in FIG. 5C, a reader / writer antenna 15 shown in FIG. 10C is the same as the reader / writer antenna 15 shown in FIG. 10B, except for the first antenna A and the second antenna B. The arrangement relationship in the frontage direction x and the depth direction y is reversed from each other. In this case as well, as in the case of FIG. 10B, the directions of the induced currents in the longitudinal overlapping portion and / or the longitudinal proximity portion can be made to substantially coincide with each other as indicated by the dashed arrows. Therefore, in the case of FIGS. 10B and 10C, the direction of the induced current of the second antenna B as a whole can be constant and can be strengthened as in the case of FIGS. 7B and 7C. In terms of the point, it is preferable to the case of FIG. 10A.

For the reader / writer antenna 15 of the first embodiment, the length direction of the shelf plate 11 of the antenna pattern 31 of the second antenna B with respect to the antenna pattern 31 of the first antenna A (specifically, the frontage direction x) In consideration of the amount of deviation in, there are four types described in the following items (a) to (d).
(A) Amount of displacement of the second antenna B with respect to the first antenna A = 0 (in the case of FIGS. 6C and 9C),
(B) Amount of displacement of the second antenna B with respect to the first antenna A <0.5L ₄ (in the case of FIGS. 6B, 7C, 9B, 10B, and 10C),
(C) Amount of deviation of the second antenna B with respect to the first antenna A = 0.5L ₄ (not illustrated), and (d) Amount of deviation of the second antenna B with respect to the first antenna A> 0.5L ₄ (in the case of FIGS. 5C and 8).

  When the first antenna A and the second antenna B are combined with each other (in other words, overlapped with each other), the shelf plates 6 and 11 to 14 for the first and second antennas A and B are arranged. Each of the chain line regions 49a, 49b in which the magnetic field components in the length direction (specifically, the frontage direction x) and in some cases the width direction (specifically, the depth direction y) of the antenna formation target member such as The first antenna A and the second antenna B are arranged such that 50 are arranged alternately as shown in FIGS. 6A, 6B, 9A and 9B without overlapping each other as shown in FIGS. 6C and 9C. Are preferably arranged respectively. In addition, when the length direction and the width direction are approximately equal, any one of these two directions can be selected as the length direction x. In order to cause the induced current shown in FIGS. 7B, 7C, 10B, and 10C to flow in one direction in the first antenna A or the second antenna B, the first and second antennas A, In the antenna pattern 31 of B, it is preferable that the portions of the antenna portions (particularly, the base line portions 43a and 43b) extending in the length direction x overlap each other or be close to each other as long as possible.

In order to arrange the chain line regions 49a and 49b in which the magnetic field components in the longitudinal direction x of the first and second antennas A and B are weakened so as not to overlap each other, the above (a) the amount of displacement described in section ~ (d) _section is preferably in the range of 0.15L ₄ ~0.75L _4, and even more preferably in the range of 0.25L ₄ ~0.55L 4. Note that when the deviation amount is out of the above range, a region having a weak magnetic field component in the length direction x extending along the width direction y of the reader / writer antenna 15 becomes more prominent. Further, not only in order to make the respective chain line regions 49a and 49b in which the magnetic field components in the longitudinal direction x of the first and second antennas A and B weaken be arranged alternately without overlapping each other, induction In order to allow the current to flow in one direction in the first or second antenna A or B, the deviation amounts described in the above items (a) to (d) are 0.15 L _{4 to} 0.35 L _4. it is preferably in the range _of, and even more preferably in the range of 0.2L ₄ ~0.3L 4. The items described in the above items (a) to (d) to the items described so far (including these four types of numerical ranges) are not limited to the first example, but are described later. The same applies to the various arrangements of the two embodiments.

(4) Feeding method to reader / writer antenna When power is fed to one of the first and second antennas A and B of the reader / writer antenna 15 shown in FIG. When the first and second antennas A and B are arranged in combination so that the induced current flows in only approximately one direction (in other words, approximately the common current direction), only one antenna is The reader / writer antenna 15 can be satisfactorily communicated with the electronic tag 19 simply by supplying power. However, in all reader / writer antennas 15 in the first embodiment such as FIG. 7A and FIG. 7B, the first and second antennas A and B are alternately fed, so that the reader / writer antenna 15 is In addition, it is possible to communicate well in a stable state.

2. Second Embodiment In the present invention, the shape and the like of the antenna patterns 31 of the first and second antennas A and B constituting the reader / writer antenna 15 provided on the shelf boards 6 and 11 to 14 are as follows. The present invention is not limited to the first embodiment shown in FIGS. 1 to 10, and various changes and modifications can be made as exemplified by the second embodiment shown in FIGS. . Therefore, in the following, the second embodiment of the present invention will be described as “(1) Basic unit pattern shape of reader / writer antenna”, “(2) Specific pattern shape of reader / writer antenna” and “(3). The method will be described with reference to FIG. 11 to FIG. The shelf board 11 in the second embodiment shown in FIGS. 11 to 18 has substantially the same configuration as the shelf board 11 in the above-described first embodiment except for the points described below. Good. Therefore, in FIGS. 11-18, the same code | symbol is attached | subjected to FIG. 1-10 and a common part, and the description is abbreviate | omitted as needed. Moreover, in the following description, although only the shelf board 11 is demonstrated, the remaining shelf boards 6 and 12-14 may be the substantially same structure as the shelf board 11, and are not the same structure. May be.

(1) Basic Pattern Shape of Reader / Writer Antenna The basic unit pattern shape C of the first and second antennas A and B constituting the reader / writer antenna 15 shown in FIG. 13C is shown in FIG. 11A. Has been. This basic unit pattern shape C is similar to that of the first antenna A except that the pattern shape of the first antenna A shown in FIG. 13A is partially omitted for clarity of illustration. It is substantially the same as the pattern shape. The basic unit pattern shape C antenna pattern 31 includes a first substantially loop-shaped antenna pattern 31a, a second substantially loop-shaped antenna pattern 31b, a third substantially loop-shaped antenna pattern 31c, And four substantially loop-shaped antenna patterns 31d. And each of these 1st-4th antenna patterns 31a-31d is comprised by the substantially rectangular shape, and is arrange | positioned sequentially from the left side to the right side along the frontage direction x. Therefore, the basic unit pattern shape C is also formed in a substantially rectangular shape as a whole.

  As shown in FIG. 11A, the leftmost antenna pattern 31a is connected to the rightmost antenna pattern 31b by a short overlapping portion 81a at the end of the shelf board 11 on the front edge portion 38 side. The rightmost antenna pattern 31d is connected to the antenna pattern 31c on the right side by a short overlapping portion 81c at the end on the front edge portion 38 side. Further, the antenna patterns 31b and 31c existing between the leftmost antenna pattern 31a and the rightmost antenna pattern 31d are different from the antenna patterns 31a and 31b on the left side of the antenna pattern 31b. Alternatively, they are connected by short overlapping portions 81a and 81b at the end portion on the rear edge portion 34 side, respectively, and the antenna patterns 31c and 31d on the right side thereof are at the end portion on the rear edge portion 34 side or the front edge portion 38 side. The short overlapping portions 81b and 81c are connected to each other. A pair of terminal portions 32a and 32b are connected to both end portions on the terminal side of the fourth antenna pattern 31d. Therefore, the antenna pattern 31 shown in FIG. 11A is a substantially loop-shaped antenna pattern having a plurality of short overlapping portions (in other words, short crossing portions) 81a to 81c as the connecting pattern portion as a whole. be able to.

  The antenna pattern 31 of the basic unit pattern shape C configured as described above is close to the rear edge 34 of the shelf board 11 and substantially parallel to the rear edge 34 as shown in FIG. 11A. A plurality of base line portions 43a that are intermittently extended so that a short intermittent portion 42a or a short overlapping portion 81b is generated between them, a second pattern portion 37, and a front edge portion 38 of the shelf board 11. A plurality of baseline portions 43b extending intermittently so that short overlapping portions 81a, 81c or short intermittent portions 42b are generated between them in a state of being close to each other and substantially parallel to the front edge portion 38. And the first and second rising portions 46, 4 rising from the end portions of the baseline portions 43a, 43b to the opposite baseline portions 43b, 43a substantially along the depth direction y, respectively. If, one or more (preferably several) and short overlapping sites 81a~81c of, it consists fourth pattern portion 41.. Further, the antenna pattern 31 of the basic unit pattern shape C includes one or a plurality (preferably a plurality of) bent portions 44a present in the intermittent portion 42a between the plurality of baseline portions 43a. And one or a plurality of (preferably a plurality of) bent portions 44b existing in the intermittent portion 42b between the plurality of baseline portions 43b.

  The bent portion 44a of the antenna pattern 31 shown in FIG. 11A is bent in a substantially rectangular shape so as to be elongated from the rear edge portion 34 side to the front edge portion 38 side of the shelf board 11, and the first and second Rising portions 46 and 47, and short overlapping portions 81a and 81c. The bent portion 44b is bent in a substantially rectangular shape so as to protrude from the front edge portion 38 side to the rear edge portion 34 side of the shelf board 11, and the first and second rising portions 46, 47 are bent. And a short overlapping portion 81b. The distance between the plurality of baseline parts 43a and the shelf center line 45 in the depth direction y is substantially the same as the distance between the plurality of baseline parts 43b and the shelf center line 45 in the depth direction y. It is. Therefore, the shelf center line 45 also serves as a virtual center line extending in the frontage direction x of the basic unit pattern shape C. Note that the fourth pattern portions of the antenna patterns 31a, 31b, and 31c are configured by the first rising portions 46 of the substantially loop-shaped antenna patterns 31a, 31b, and 31c, respectively. In addition, the second pattern portions of the antenna patterns 31b, 31c, and 31d are respectively configured by the second rising portions 47 of the substantially loop-shaped antenna patterns 31b, 31c, and 31d. Therefore, the first rising portion 46 is a component of the fourth pattern portion. The second rising portion 47 is a component of the second pattern portion.

  On the other hand, in the case of the antenna pattern 31 shown in FIG. 12A described later, as in the case of the antenna pattern 31 shown in FIG. 4A described above, the first rising portions 46 on the rear edge portion 34 side and the front edge portion 38 side are The fourth pattern portions 41a, 41b, and 41c are constituent elements, and the second rising portions 47 on the rear edge portion 34 side and the front edge portion 38 side are constituent elements of the second pattern portions 37b, 37c, and 37d. It has become. And in these 4th and 2nd pattern parts 41a-41c, 37b-37d, although the cross | intersection parts 83a-83c exist, the discontinuous part 59 (refer FIG. 4A) does not exist. Accordingly, the long cross pattern portions 82a to 82c also serve as the connection pattern portion and the constituent elements of the second and fourth pattern portions 41a to 41c and 37b to 37d, respectively.

FIG. 12A shows a modification of the basic unit pattern shape C shown in FIG. 11A. The basic unit pattern shape C shown in FIG. 12A is different from the basic unit pattern shape C shown in FIG. 11A in that the short overlapping portions 81a to 81c in the basic unit pattern shape C shown in FIG. The basic unit pattern shape C shown in FIG. 12A is that it is changed to long cross pattern portions 82a to 82c that are elongated along the depth direction y. It should be noted that the long cross pattern portions 82a to 82c as the connecting pattern portions have crossing portions 83a to 83c, as a matter of course. Therefore, it can be said that the basic unit pattern shape C shown in FIG. 12A is a modification of the basic unit pattern shape C shown in FIG. 4A. Then, the two elongate unit pattern portion constituting these long cross pattern portion 82a~82c respectively is not parallel to the depth direction y is inclined by a predetermined inclination angle theta _2. The inclination angle θ ₂ is about 6.5 ° in the illustrated embodiment. However, in the present invention, the inclination angle θ ₂ is generally preferably in the range of 0 ° to 15 °, more preferably in the range of 0 ° to 10 °, from the viewpoint of practicality. preferable. Therefore, it can be said that each of these two longitudinal unit pattern portions extends substantially along the depth direction y.

  Therefore, the antenna pattern 31 of the basic unit pattern shape C shown in FIG. 12A is one or more (preferably, between the plurality of baseline portions 43a (in other words, the intermittent portion 42a). A plurality of bent portions 44a and one or a plurality of (preferably a plurality of) bent portions 44b existing between the plurality of baseline portions 43b (in other words, the intermittent portion 42b). I have. The bent portion 44a is bent in a substantially triangular shape (in the illustrated embodiment, an isosceles triangle shape) so as to protrude from the rear end portion 34 side of the shelf board 11 toward the front edge portion 38 side. In addition, the first and second rising portions formed by one half of the long cross pattern portions 82a to 82c on the rear edge portion 38 side (that is, a sharp mountain-shaped portion having the intersection portions 83a to 83c as vertices) It consists of 46 and 47. Further, the bent portion 44b is bent in a substantially triangular shape (in the illustrated embodiment, an isosceles triangle shape) so as to protrude from the front edge portion 38 side to the rear edge portion 34 side of the shelf board 11. The first and second rising edges formed by the other half portion of the long cross pattern portions 82a to 82c on the front edge portion 34 side (that is, the sharp mountain-shaped portions having the intersection portions 83a to 83c as vertices) It consists of parts 46 and 47.

  In the basic unit pattern shape C shown in FIG. 12A, the intersecting portions 83a to 83c of the cross pattern portions 82a to 82c exist substantially on the shelf centerline 45. Further, the distance between the plurality of baseline portions 43a and the shelf center line 45 in the depth direction y is substantially the same as the distance between the plurality of baseline portions 43b and the shelf center line 45 in the depth direction y. is there. Therefore, the shelf center line 45 also serves as a virtual center line extending in the frontage direction x of the basic unit pattern shape C.

  From a different viewpoint, the antenna pattern 31 of the basic unit pattern shape C shown in FIG. 11A is a large loop antenna pattern (not shown) that has neither intersection nor overlap for forming the antenna pattern 31. ) Is twisted at one or more suitable locations to form one or a plurality of twist overlapping portions (that is, short overlapping portions, in other words, twist connecting portions) 81a to 81c in the above-mentioned large loop shape. It can be said that the antenna pattern is formed. In this case, specifically, the third substantially loop-shaped antenna pattern 31c includes one baseline portion (that is, the first pattern portion) 43a and the other baseline portion (that is, the third pattern portion). It can be said that the second and fourth substantially loop-shaped antenna patterns 31b and 31d are respectively half-twisted (that is, twisted by 180 °) so that 43b is interchanged. Further, the first substantially loop-shaped antenna pattern 31a is configured such that one baseline portion (ie, the first pattern portion) 43a and the other baseline portion (ie, the third pattern portion) 43b are interchanged with each other. Furthermore, it can be said that the portion on the right edge 40 side in the frontage direction x is half twisted with respect to the second substantially loop-shaped antenna pattern 31b. The above replacement can be achieved by twisting 1.5 times, twisting 2.5 times, and the like. In the text, “twisted connection pattern portion” or “twisted connection portion” also means connection pattern portions 81a to 81c or a connection portion generated by the above-described replacement by twisting. Accordingly, the short overlapping portions 81a to 81c constitute a twist connecting pattern portion and a twist connecting portion, respectively.

  In addition, the antenna pattern 31 of the basic unit pattern shape C shown in FIG. 12A is, from a different viewpoint, a large loop antenna pattern (FIG. 12) that has neither intersection nor overlap for forming the antenna pattern 31. (Not shown) by twisting at one or more appropriate locations, one or more twisted intersections (i.e., long cross-pattern portions, in other words, twisted coupling portions) 82a-82c are described above. It can be said that it is formed in a large loop antenna pattern. In this case, specifically, the third substantially loop-shaped antenna pattern 31c includes one baseline portion (that is, the first pattern portion) 43a and the other baseline portion (that is, the third pattern portion). It can be said that the second and fourth substantially loop-shaped antenna patterns 31b and 31d are respectively half-twisted (that is, twisted by 180 °) so that 43b is interchanged. Further, the first substantially loop-shaped antenna pattern 31a is configured such that one baseline portion (ie, the first pattern portion) 43a and the other baseline portion (ie, the third pattern portion) 43b are interchanged with each other. Furthermore, it can be said that the portion on the right edge 40 side in the frontage direction x is half twisted with respect to the second substantially loop-shaped antenna pattern 31b. The above replacement can be achieved by twisting 1.5 times, twisting 2.5 times, and the like. In the text, “twisted connection pattern portion” or “twisted connection portion” also means connection pattern portions 82a to 82c or a connection portion generated by the above-described replacement by twisting. Accordingly, the long cross pattern portions 82a to 82c constitute a twist connection pattern portion and a twist connection portion, respectively.

One feature of the basic unit pattern shape C shown in FIG. 11A is the direction of the current flowing in each longitudinal pattern portion of the antenna pattern 31 when a loop current is passed through the basic unit pattern shape C. For example, when a loop current is passed through the basic unit pattern shape C from the terminal portion 32a of the pair of terminal portions 32a and 32b toward the terminal portion 32b, as shown by the solid line arrows in FIG. As is apparent with reference to the solid-line arrows in FIG. 15B, the currents in the directions described in the following items (a) and (b) flow in each longitudinal pattern portion of the pattern 31.
(A) A current flows alternately in the opposite direction in the longitudinal pattern portion (that is, the four baseline portions 43a and the four baseline portions 44b) extending substantially in the frontage direction x (in other words, On the right edge 40 side, the baseline portions 43a of the first and third substantially loop-shaped antenna patterns 31a and 31c and the baseline portions 43b of the second and fourth substantially-loop shaped antenna patterns 31b and 31d Current flows from the left side edge 36 toward the left side edge 36, and the base line portion 43a of the second and fourth substantially loop-shaped antenna patterns 31b and 31d and the first and third substantially loop-shaped antenna patterns 31a and 31c. In the baseline portion 43b, a current flows from the left edge portion 36 side toward the right edge portion 40 side), and (b) depth. Longitudinal pattern portions extending substantially in the direction y (ie, the second and fourth pattern portions 37, 41 and the first and second rising portions 46 of the two bent portions 44a and one bent portion 44b, 47) that current flows alternately in the opposite direction (in other words, the second and fourth pattern portions 37 and 41, the second substantially loop-shaped antenna pattern 31b, and the third substantially loop-shaped antenna). The first and second rising portions 46 and 47 of the bent portion 44a between the pattern 31c and the current flow from the rear edge portion 34 side toward the front edge portion 38 side, and the first substantially loop-shaped antenna Between the pattern 31a and the second substantially loop-shaped antenna pattern 31b, and between the third substantially loop-shaped antenna pattern 31c and the fourth substantially loop-shaped antenna pattern 31d, The first and second rising portions 46, 47 of the two bent portions 44a between, a current flows through the trailing edge 34 side from the front edge portion 38 side).

Further, one characteristic of the basic unit pattern shape C shown in FIG. 12A is the direction of the current flowing in each longitudinal pattern portion of the antenna pattern 31 when a loop current is passed through the basic unit pattern shape C. For example, when a loop current is passed through the basic unit pattern shape C from the terminal portion 32a of the pair of terminal portions 32a and 32b toward the terminal portion 32b, each longitudinal pattern portion of the antenna pattern 31 is shown in FIG. As apparent from the solid line arrow of 7B, the currents in the directions described in the following items (c) and (d) flow.
(C) A current flows alternately in the opposite direction in the longitudinal pattern portion (that is, the four baseline portions 43a and the four baseline portions 44b) extending substantially in the frontage direction x (in other words, On the right edge 40 side, the baseline portions 43a of the first and third substantially loop-shaped antenna patterns 31a and 31c and the baseline portions 43b of the second and fourth substantially-loop shaped antenna patterns 31b and 31d Current flows from the left side edge 36 toward the left side edge 36, and the base line portion 43a of the second and fourth substantially loop-shaped antenna patterns 31b and 31d and the first and third substantially loop-shaped antenna patterns 31a and 31c. In the baseline portion 43b, a current flows from the left edge portion 36 side to the right edge portion 40 side), and (d) depth. Longitudinal pattern portions extending approximately in the direction y (ie, the first and second rising portions 46 of the second and fourth pattern portions 37, 41 and the two bent portions 44a and one bent portion 44b). 47) that current flows alternately in the opposite direction (in other words, the second and fourth pattern portions 37 and 41, the second substantially loop-shaped antenna pattern 31b, and the third substantially loop-shaped antenna). In the first and second rising portions 46 and 47 of the bent portions 44a and 44b between the antenna pattern 31c, current flows from the rear edge portion 34 side to the front edge portion 38 side, and the first substantially loop Between the antenna pattern 31a having the shape and the second substantially loop-shaped antenna pattern 31b, and between the third substantially loop-shaped antenna pattern 31c and the fourth substantially loop-shaped antenna pattern. The bent portion 44a between the 31d, the first and second rising portions 46 and 47 of 44b, a current flows through the trailing edge 34 side from the front edge portion 38 side).

  Another feature of the basic unit pattern shape C shown in FIG. 11A and FIG. 12A is that the magnetic field component in the frontage direction x parallel to the surface of the shelf board 11 is approximately periodic according to its position along the frontage direction x. 11B and FIG. 12B tend to be weakened in the hatched region 49. This is largely due to the antenna portions extending in the depth direction y (ie, the second and fourth pattern portions 37 and 41, the first and second rising portions 46 and 47, and the long cross pattern portions 82a to 82c). This is because the generated magnetic field component in the frontage direction x becomes small at a position intermediate between these adjacent antenna portions. Therefore, in the basic unit pattern shape C shown in FIGS. 11A and 12A alone, when the electronic tag 19 (see FIG. 2) is placed in the hatched area 49 so as to be parallel to the yz plane, it is for the reader / writer. There is a possibility that the antenna 15 (in other words, the basic unit pattern shape C shown in FIGS. 11A and 12A) cannot communicate with the electronic tag 19.

In order to communicate with the electronic tag 19 placed so that the reader / writer antenna 15 is parallel to the yz plane, as described above, the front direction of the magnetic field generated from each antenna portion of the reader / writer antenna 15 is used. The x component has an effect. Therefore, it is preferable that the antenna portion of the antenna 15 extending in the approximately depth direction y extends substantially perpendicular to the frontage direction x as shown in FIG. 11A. However, as the inclination angle theta ₂ shown in FIG. 12A, it may be slightly an inclined angle. Of the antenna portions (ie, the second and fourth pattern portions 37 and 41, the first and second rising portions 46 and 47, and the long cross pattern portions 82a to 82c) extending in the depth direction y. In the antenna portions adjacent to each other, the width in the front-end direction x of the incommunicable region of the basic unit pattern shape C with respect to the electronic tag 19 placed parallel to the yz plane is made as constant as possible along the depth direction y. Thus, it is preferable that they are substantially parallel to each other.

11B and 12B show a region 49 where the magnetic field component in the frontage direction x parallel to the surface of the shelf 11 for the basic unit pattern shape C shown in FIGS. 11A and 12A is weakened. 11C and FIG. 12C show a region 50 in which the magnetic field component in the depth direction y parallel to the surface of the shelf plate 11 for the basic unit pattern shape C shown in FIGS. 11A and 12A is weakened. And the magnetic field component of the depth direction y parallel to the surface of the shelf board 11 also tends to become weak in the hatched area 50 in FIGS. 11C and 12C for the same reason as in the case of the frontage direction x described above. Therefore, the antenna portions (that is, the first and second baseline portions 43a and 43b) extending in the frontage direction x in the basic unit pattern shape C correspond to the electronic tag 19 placed parallel to the xz plane. It is preferable that the width in the depth direction y of the incommunicable region of the basic unit pattern shape C is substantially parallel to each other so as to be as constant as possible along the frontage direction x. However, the antenna portion 43a, 43b need not necessarily substantially parallel to one another, to the same extent as if the inclination angle theta _2, may be inclined to each other.

(2) Specific Pattern Shape of Reader / Writer Antenna The reader / writer antenna 15 has substantially the same antenna pattern shape 31 and / or similar antenna pattern as the basic unit pattern shape C described in the above section (1). The first and second antennas A and B each having the shape 31 are combined and arranged. The first and second antennas are arranged such that the chain line regions 49 in which the magnetic field components in the frontage direction x of the first and second antennas A and B are weakly arranged without overlapping each other. A and B are arranged, respectively.

  In the reader / writer antenna 15 shown in FIG. 13C, one of the first to fourth antenna patterns 31a to 31d is omitted for the sake of clarity in comparison with the basic unit pattern shape C shown in FIG. 11A. The first antenna A shown in FIG. 13A and the second antenna B shown in FIG. 13B similar to the first antenna A shown in FIG. 13A are arranged in combination. The first and second antennas A and B have a pattern shape in which one of the first to fourth antenna patterns 31a to 31d is omitted compared to the basic unit pattern shape C shown in FIG. 11A. Each has. Therefore, as shown in FIGS. 13A and 13B, the first antenna A has hatched areas similar to the hatched areas 49 and 50 of the basic unit pattern shape C shown in FIGS. 11B and 11C. Further, the second antenna B has a substantially loop-shaped antenna pattern 31 that is substantially the same as that of the first antenna A, and only the positions of the pair of terminal portions 32a and 32b are located behind the shelf board 11. It differs from the first antenna A shown in FIG. 13A only in that it is changed from the edge 34 side to the front edge 38 side. For this reason, as shown in FIG. 13B, the second antenna B also has a hatched area 49b that is substantially the same as the hatched area 49a of the first antenna A shown in FIG. 13A. Therefore, the first antenna A and the second antenna B have substantially the same pattern shape (that is, the antenna pattern 31).

The reader / writer antenna 15 is configured by arranging the first and second antennas A and B in combination with each other as shown in FIG. 13C. In this combination, as shown in FIG. 13C, the second antenna B is approximately ½ of the distance L ₄ (see FIG. 13A) in the frontage direction x with respect to the first antenna A (ie, approximately 0. a 5L _4, in the illustrated embodiment, while being arranged with a shift to the left by about 100 mm), are arranged in a state that does not deviate in the depth direction y. Therefore, the above description of the basic unit pattern shape C applies not only to the first antenna A, but also to the second antenna B, except for the change caused by the difference between the two. The same applies except for changes that occur when the positions of the pair of terminal portions 32a and 32b are different. And the 1st antenna A and the 2nd antenna B have the longitudinal overlapping parts 91-100 which mutually overlap in the up-down direction z, as shown to FIG. 13C. Further, when the second antenna B is shifted in the frontage direction x with respect to the first antenna A, the performance of the reader / writer antenna 15 is substantially equivalent regardless of whether the second antenna B is shifted leftward or rightward.

In the case of the reader / writer antenna 15 shown in FIG. 13C, the hatched area 49a in the frontage direction x for the first antenna A and the hatched area 49b in the frontage direction x for the second antenna B are shown in FIG. 14A. As shown, they are staggered at approximately equal intervals (in other words, approximately 0.5 L ₄ intervals). FIG. 14B shows a first modification of the reader / writer antenna 15 shown in FIG. 13C. In the reader / writer antenna 15 shown in FIG. 14B, the distance at which the second antenna B is shifted to the left side with respect to the first antenna A is approximately 0.5 L ₄ (in the illustrated embodiment, about 37.5 mm). The configuration is substantially the same as that of the reader / writer antenna 15 shown in FIG. 14A. In this case, the hatched area 49a and the hatched area 49b are staggered as shown in FIG. 14B, but the distance between them is not evenly spaced.

  In the case of the reader / writer antenna 15 shown in FIGS. 14A and 14B, the diagonally shaded region 49a or 49b having a weak magnetic field component in the frontage direction x by one of the first and second antennas A and B is Supplemented by the antenna. Therefore, there is substantially no region where the reader / writer antenna 15 cannot communicate with the electronic tag 19 parallel to the yz plane. In the case of the reader / writer antenna 15 shown in FIG. 14C as Reference Example 1 of the reader / writer antenna 15 shown in FIG. 13C, the antenna pattern 31 of the first antenna A and the antenna pattern 31 of the second antenna B are shown. Are substantially completely overlapped with each other in the vertical direction z. Therefore, in the case of the reader / writer antenna 15 shown in FIG. 14C, the communication impossible areas 49a and 49b similar to those in the case of the first antenna A alone and the second antenna B shown in FIGS. 13A and 13B, respectively. Exist.

  In one aspect of the present invention, a magnetic field generated when power is supplied to one of the first and second antennas A and B, and the value of the induced current generated in the other antenna is increased. Is preferred. Therefore, the direction of the induced current of the entire first antenna A or the entire second antenna B is such that most of the longitudinal overlapping portions 91 to 100 of the first and second antennas A and B and / or the most. It is preferable to arrange the first and second antennas A and B so as to coincide with the direction of the induced current generated in the most part of the adjacent longitudinal proximity portions.

  For example, in the case of the reader / writer antenna 15 shown in FIG. 13C, when the first antenna A is fed in the direction of the solid arrow in FIG. 15A (or the opposite direction), the first and second antennas are supplied. The induced current generated in the second antenna B in the longitudinal overlapping portions 91 to 100 of A and B is the direction of the broken arrow that is opposite to the direction of the solid arrow in FIG. 15A (or the opposite direction). (Or vice versa). However, in this case, the second and fourth pattern portions 37 and 41 of the second antenna B and the first and second rising portions 46 and 47 are respectively connected to the second and fourth patterns of the first antenna A. Since the pattern portions 37 and 41 and the corresponding portions of the first and second rising portions 46 and 47 are not particularly overlapped and / or not close to each other, the second antenna B is guided at these corresponding portions. Is hard to get up. The direction of the induced current in the longitudinal overlapping portions 92, 94, 97, and 99 of the second antenna B is the same as the direction of the induced current in the longitudinal overlapping portions 91, 93, 96, and 98 of the second antenna B. Is the opposite. Therefore, it can be said that the direction in which the induced current flows in the second antenna B is indefinite.

    On the other hand, in the case of the reader / writer antenna 15 shown in FIG. 14B, the antenna portions (that is, the second and fourth pattern portions 37, 41 and the first and second patterns B) extending in the depth direction y of the second antenna B. The direction of the induced current generated in the second rising portions 46, 47) is such that the antenna portion of the first antenna A is close to and substantially parallel to the antenna portions 37, 41, 46, 47 of the second antenna B. In response to guidance from (that is, the second and fourth pattern portions 37 and 41 and the first and second rising portions 46 and 47), the direction is indicated by the dashed arrows in FIG. 15B. The direction indicated by the dashed arrow in FIG. 15B is different from the direction indicated by the broken arrow of the longitudinal overlapping portions 91 to 100 and the longitudinal adjacent portion shown in FIG. 15A. This corresponds to the direction of the induced current of the entire antenna B. Note that FIG. 15C shows a modification of the reader / writer antenna 15 shown in FIG. 13C, in which the way of shifting the first and second antennas A and B in the frontage direction x is opposite to that in FIG. 15B. It is shown as 2. Also in the case shown in FIG. 15C, the direction indicated by the dashed arrow of the induced current is substantially the same as in the case of FIG. 15B. Therefore, in the cases of FIGS. 15B and 15C, the direction of the induced current of the second antenna B as a whole can be constant and can be intensified with each other. Therefore, in terms of the induced current, it is preferable to the case of FIG. 15A.

Further, the reader / writer antenna 15 shown in FIG. 16 is a modification 3 of the reader / writer antenna 15 shown in FIG. 13C. Then, the reader writer antenna 15 shown in FIG. 16, the reader writer antenna 15 shown in FIG. 13C, a substantially spacing L ₅ second antenna B in the depth direction y with respect to the first antenna A 1 / 6 (that is, approximately 0.17L ₅ and approximately 40 mm in the illustrated embodiment) is shifted to the front. In this case, since the longitudinal overlapping portions 91 to 100 in FIG. 13C are changed to the longitudinal proximity portions 91 to 100 as shown in FIG. 16, the first and second antennas A as shown in FIG. 17A. , B can not prevent the hatched areas 49a, 49b having weak magnetic field components in the frontage direction x from overlapping each other, and the magnetic field components in the depth direction y for the first and second antennas A, B are weak. The hatched areas 50 can be prevented from overlapping each other. Therefore, the diagonally shaded area 50 having a weak magnetic field component in the depth direction y for one of the first and second antennas A and B is supplemented by the other antenna. However, in this case, since the direction of the induced current in the longitudinal proximity portions 91 to 100 is as shown by the dashed arrow as shown in FIG. 18A, the direction of the induced current of the entire second antenna B is As in the case of FIG. 15A, it is indefinite. FIGS. 17B and 18B show Modification 4 of the reader / writer antenna 15 shown in FIG. 13C. The reader / writer antenna 15 shown in FIG. 17B and FIG. 18B is an interval for shifting the second antenna B to the left side in the frontage direction x with respect to the first antenna A in the reader / writer antenna 15 shown in FIG. and it is obtained by approximately 0.25 L _4. Also in the case of the reader / writer antenna 15 shown in FIG. 18B, as shown in FIG. 17B, not only can the hatched areas 49a and 49b not overlap each other, but also the hatched areas 50 do not overlap each other. In addition, the directions of the induced currents at the longitudinal overlap portion and the longitudinal proximity portion can be substantially matched to each other as shown by the dashed arrows in FIG. 18B.

  FIG. 17C shows Reference Example 2 of the reader / writer antenna 15 shown in FIG. 13C. The reader / writer antenna 15 shown in FIG. 17C is the same as the reader / writer antenna 15 shown in FIG. 16 except that all antenna portions extending in the depth direction y of the first antenna A (that is, the second and second antennas). 4 pattern portions 37, 41 and all of the first and second rising portions 46, 47) extend in the depth direction y of the second antenna B, and all the antenna portions 37, 41, 46, 47. Are overlapped with each other in the vertical direction z. Therefore, in the case of the reader / writer antenna 15 shown in FIG. 17C, most of the hatched regions 49a and 49b having weak magnetic field components in the front-facing direction x of the first and second antennas A and B overlap each other. . Further, as a fifth modification of the reader / writer antenna 15 shown in FIG. 13C, the reader / writer antenna 15 shown in FIG. 18C is the same as the first antenna A and the second antenna B in the reader / writer antenna 15 shown in FIG. 18B. The arrangement relationship in the frontage direction x and the depth direction y is reversed from each other. Also in this case, as in the case of FIG. 18B, the directions of the induced currents in the longitudinal proximity portions can be made to coincide with each other as indicated by the dashed arrows.

(3) Feeding method to reader / writer antenna When power is fed to one of the first and second antennas A and B of the reader / writer antenna 15 shown in FIG. When the first and second antennas A and B are arranged in combination so that the induced current flows in only approximately one direction (in other words, approximately the common current direction), only one antenna is The reader / writer antenna 15 can be satisfactorily communicated with the electronic tag 19 simply by supplying power. However, in all the reader / writer antennas 15 in the second embodiment such as FIG. 15A and FIG. 15B, the first and second antennas A and B are alternately fed so that the reader / writer antenna 15 is changed. In addition, it is possible to communicate well in a stable state.

  Although the first and second embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments and is based on the gist of the invention described in the claims. Various changes and modifications are possible.

  For example, in the first and second embodiments described above, the upper and lower five-stage shelf boards 6 and 11 to 14 are provided on the article management shelf 1, but the shelf boards are not necessarily provided in the upper and lower five stages. 2 or 4 or 6 or more stages may be provided one above the other. In some cases, only one stage may be provided.

  In the first and second embodiments described above, the present invention is applied to the article placement shelf 1. However, the present invention can be applied to a table on which various articles are placed such as a counter table such as a reception counter table in a library, a table, a desk, etc., and as a distribution reading antenna in a production line. Can also be used. Therefore, the reader antenna according to the present invention is not limited to a rectangular substrate such as a shelf board of an article placement shelf, but is also applicable to a substrate having a square, a parallelogram, other trapezoids, an oval, and other various shapes. Can be incorporated.

  In the first and second embodiments described above, the antenna patterns 31 of the first and second antennas A and B of the reader / writer antenna 15 are wound once, but are spirally wound. It may be a multi-turn winding that is wound a plurality of times.

  In the first and second embodiments described above, the antenna pattern elements 35, 37, 39, 41, 43, 46, 47 of the first and second antennas A, B of the reader / writer antenna 15 are used. Most of the connecting parts between each other have a sharp shape such as a right angle. However, a round shape may be sufficient as one place or several places or all the places of these connection parts.

  In the first and second embodiments described above, the number of bent portions 44a and 44b of the first and second antennas A and B of the reader / writer antenna 15 is set to 6 in the first embodiment. 3 or 6 in the second embodiment. However, the number of the bent portions 44a and 44b is not necessarily limited to these numbers, and may be an arbitrary multiple number larger or smaller than that.

  Furthermore, in the first and second embodiments described above, the plurality of substantially loop-shaped antenna patterns 31a to 32d of the first and second antennas A and B of the reader / writer antenna 15 are short. The cross pattern portions 60a to 60c, the short overlapping portions 81a to 81c, and the long cross pattern portions 82a to 82c are sequentially twisted and connected. However, the means for sequentially twisting and connecting the substantially loop-shaped antenna patterns 31a to 31d may be a mixture of a plurality of types of these three types, and is further limited to these three types. It is not a thing but various twist connection means can be employ | adopted. For example, the torsional coupling means includes one of the short cross pattern portions 60a to 60c and the long cross pattern portions 82a to 82c in which the cross portions 61a to 61c and 83a to 83c are changed to short overlap portions 81a to 81c, respectively. Types or multiple types may be included.

It is a perspective view of the goods mounting shelf in the 1st example which applied the present invention to the goods mounting shelf. Example 1 FIG. 2 is an enlarged plan view of the electronic tag in FIG. 1. Example 1 FIG. 2 is an enlarged longitudinal sectional view of a part of the uppermost shelf board in FIG. 1. Example 1 It is a top view which shows the basic unit pattern shape of the antenna for reader / writers of the uppermost shelf of FIG. Example 1 It is the top view similar to FIG. 4A which added the state of the magnetic field component of the frontage direction by the basic unit pattern shape of FIG. 4A. Example 1 It is the top view similar to FIG. 4A which added the state of the magnetic field component of the depth direction by the basic unit pattern shape of FIG. 4A. Example 1 It is a top view which shows only the 1st antenna of the two antennas which comprise the antenna for reader / writers of the uppermost shelf of FIG. Example 1 It is a top view which shows only the 2nd antenna of the two antennas which comprise the antenna for reader / writers of the shelf board of FIG. Example 1 It is a top view which shows both of the two antennas which comprise the antenna for reader / writers of the shelf of the uppermost stage of FIG. Example 1 It is the top view which added the state of the magnetic field component of the frontage direction by two antennas which comprise the antenna for reader / writers of FIG. 5C of the shelf of the uppermost stage of FIG. Example 1 It is the same top view as FIG. 6A which shows the modification 1 of the antenna for reader / writers of FIG. 5C. Example 1 It is the same top view as FIG. 6A which shows the reference example 1 of the antenna for reader / writers of FIG. 5C. Example 1 It is a top view which shows the direction of the electric power feeding current and induction current of the antenna for reader / writers of FIG. 5C of the shelf at the top of FIG. Example 1 It is the top view similar to FIG. 7A which shows the antenna for reader / writers of FIG. 6B. Example 1 It is the same top view as FIG. 7A which shows the modification 2 of the antenna for reader / writers of FIG. 5C. Example 1 It is the same top view as FIG. 5C which shows the modification 3 of the antenna for reader / writers of FIG. 5C. Example 1 FIG. 9 is a plan view of the shelf board of FIG. 1 to which the state of magnetic field components in the frontage direction by two antennas constituting the reader / writer antenna of FIG. 8 is added. Example 1 It is the same top view as FIG. 9A which shows the modification 4 of the antenna for reader / writers of FIG. 5C. Example 1 FIG. 9B is a plan view similar to FIG. 9A showing Reference Example 2 of the reader / writer antenna of FIG. 5C. Example 1 FIG. 9 is a plan view showing directions of supply current and induction current of the reader / writer antenna of FIG. 8 on the shelf board of FIG. 1. Example 1 It is a top view similar to FIG. 10A which shows the antenna for reader / writers of FIG. 9B. Example 1 It is the same top view as FIG. 10B which shows the modification 5 of the antenna for reader / writers of FIG. 5C. Example 1 It is a top view which shows the basic unit pattern shape of the antenna for reader / writers of the uppermost shelf in the 2nd Example which applied this invention to the article | item mounting shelf. (Example 2) FIG. 11B is a plan view similar to FIG. 11A to which the state of the magnetic field component in the frontage direction according to the basic unit pattern shape of FIG. 11A is added. (Example 2) FIG. 11B is a plan view similar to FIG. 11A to which the state of the magnetic field component in the depth direction according to the basic unit pattern shape of FIG. (Example 2) It is a top view which shows the modification of the basic unit pattern shape of FIG. 11A of the uppermost shelf board by 2nd Example of this invention. (Example 2) It is a top view similar to FIG. 12A to which the state of the magnetic field component in the frontage direction according to the basic unit pattern shape of FIG. 12A is added. (Example 2) It is a top view similar to FIG. 12A to which the state of the magnetic field component in the depth direction by the basic unit pattern shape of FIG. 12A is added. (Example 2) It is a top view which shows only the 1st antenna of the two antennas which comprise the antenna for reader-writers of the uppermost shelf in the 2nd Example of this invention. (Example 2) It is a top view which shows only the 2nd antenna of the two antennas which comprise the antenna for reader / writers of the uppermost shelf in the 2nd Example of this invention. (Example 2) It is a top view which shows both the two antennas which comprise the antenna for reader / writers of the shelf of the uppermost stage in the 2nd Example of this invention. (Example 2) It is the top view which added the state of the magnetic field component of the frontage direction by two antennas which comprise the antenna for reader / writers of FIG. 13C of the uppermost shelf board in 2nd Example of this invention. (Example 2) FIG. 14B is a plan view similar to FIG. 14A showing Modification Example 1 of the reader / writer antenna of FIG. 13C. (Example 2) It is a top view similar to FIG. 14A which shows the reference example 1 of the antenna for reader / writers of FIG. 13C. (Example 2) It is a top view which shows the direction of the electric power feeding current and induction current of the antenna for reader / writers of FIG. 13C of the uppermost shelf in the 2nd Example of this invention. (Example 2) It is a top view similar to FIG. 15A of the antenna for reader / writers of FIG. 14B. (Example 2) It is a top view similar to FIG. 15A of the modification 2 of the antenna for reader / writers of FIG. 13C. (Example 2) 13C is a plan view similar to FIG. 13C, showing a third modification of the reader / writer antenna of FIG. 13C. FIG. (Example 2) It is the top view which added the state of the magnetic field component of the frontage direction by two antennas which comprise the antenna for reader / writers of FIG. 16 of the shelf board in 2nd Example of this invention. (Example 2) It is the same top view as FIG. 17A which shows the modification 4 of the antenna for reader / writers of FIG. 13C. (Example 2) It is the same top view as FIG. 17A which shows the reference example 2 of the antenna for reader / writers of FIG. 13C. (Example 2) It is a top view which shows the direction of the supply current of the antenna for reader / writers of FIG. 16, and the induced current of the uppermost shelf in the 2nd Example of this invention. (Example 2) It is a top view similar to FIG. 18A which shows the antenna for reader / writers of FIG. 17B. (Example 2) FIG. 18D is a plan view similar to FIG. 18B showing Modification Example 5 of the reader / writer antenna of FIG. 13C. (Example 2)

Explanation of symbols

A First antenna B Second antenna x Frontage direction (first direction)
y Depth direction (second direction)
1 Article placement shelf 6 Bottom shelf (antenna forming target member)
11 Top shelf (antenna formation target member)
12 Second shelf board (antenna forming target member)
13 Third shelf (antenna formation target member)
14 4th stage shelf board (antenna forming target member)
15 Antenna for reader / writer (antenna for reader)
23 Upper glass plate (main components)
24 Lower glass plate (main components)
25 Intermediate film (insulating layer)
31 antenna pattern 31a first substantially loop-shaped antenna pattern 31b second substantially loop-shaped antenna pattern 31c third substantially loop-shaped antenna pattern 31d fourth substantially loop-shaped antenna pattern 32a terminal portion 32b terminal portion 34 Rear edge (back edge)
36 Left edge 37 toward second pattern portion 37b Second pattern portion 37c Second pattern portion 37d Second pattern portion 40 Right edge 41 toward fourth pattern portion 41a Fourth pattern portion 41b 4th pattern part 41c 4th pattern part 43a Baseline part (1st pattern part)
43b Baseline part (third pattern part)
44a bent portion 44b bent portion 46 first rising portion (component of fourth pattern portion)
47 Second rising portion (component of second pattern portion)
60a Short cross pattern part (pattern part for twist connection)
60b Short cross pattern part (twisted connection pattern part)
60c short cross pattern part (pattern part for twist connection)
81a Short overlapping part (pattern part for twist connection)
81b Short overlapping part (pattern part for twist connection)
81c Short overlapping part (Pattern for twist connection)
82a Long cross pattern part (twisted connection pattern part)
82b Long cross pattern part (pattern part for twist connection)
82c Long cross pattern part (twisted connection pattern part)

Claims (15)

In the reader antenna including the first and second antennas that are formed on the antenna formation target member in a state of being insulated from each other and being superimposed on each other,
Each of the first and second antennas includes a plurality of substantially loop-shaped antenna patterns that are sequentially arranged substantially along the first direction,
Each of the plurality of substantially loop-shaped antenna patterns includes a first pattern portion provided on a first side in a second direction orthogonal to the first direction of the antenna formation target member; A second pattern portion provided on the first side of the antenna forming target member in the first direction, and a second pattern portion opposite to the first side in the second direction of the antenna forming target member. And a fourth pattern portion provided on the second side opposite to the first side in the first direction of the antenna forming target member. It is composed of roughly rectangular shape,
Each of the plurality of substantially loop-shaped antenna patterns is coupled to another substantially loop-shaped antenna pattern adjacent thereto by a twist coupling pattern portion,
The second pattern portion or the fourth pattern portion of the first antenna is between the second pattern portion corresponding to the second antenna portion and the fourth pattern portion corresponding to the second antenna portion. An antenna for a reader, wherein   2. The reader antenna according to claim 1, wherein the twist connection pattern portion is one type or a plurality of types selected from a twist intersection portion and a twist overlap portion.   3. The reader antenna according to claim 1, wherein the twist coupling pattern portion is one type or a plurality of types selected from a short cross pattern portion, a short overlap portion, and a long cross pattern portion. . The twist connecting pattern portion is composed of a short cross pattern portion,
Each of the plurality of substantially loop-shaped antenna patterns is connected to another substantially loop-shaped antenna pattern adjacent thereto by the short cross pattern portion at an intermediate portion in the second direction. The reader antenna according to claim 1, 2, or 3. The torsional coupling pattern portion is formed by another substantially loop-shaped antenna pattern adjacent to one of the first and third pattern portions extending approximately along the first direction. Consisting of short overlapping sites constructed by further extending to
4. Each of the plurality of substantially loop-shaped antenna patterns is connected to another adjacent substantially loop-shaped antenna pattern by the short overlapping portion. Reader antenna. The twist coupling pattern portion includes one of the second and fourth pattern portions extending approximately along the second direction of each of the plurality of substantially loop-shaped antenna patterns, And a long cross pattern portion constituted by the other of the second and fourth pattern portions extending substantially along the second direction of each of the substantially loop-shaped antenna patterns adjacent to each other Consisting of
4. Each of the plurality of substantially loop-shaped antenna patterns is connected to another substantially loop-shaped antenna pattern adjacent thereto by the long cross pattern portion. The antenna for readers described in 1.   The second antenna is displaced in the first direction with respect to the first antenna by an average length of 0.15 to 0.35 per one first pattern portion. The reader antenna according to any one of claims 1 to 6, wherein:   The reader antenna according to claim 1, wherein the reader antenna is configured to supply power to only one of the first and second antennas.   The reader antenna according to claim 1, wherein the reader antenna is configured to alternately supply power to the first and second antennas.   The reader antenna according to claim 1, wherein the reader antenna is configured as a reader / writer antenna. The antenna formation target member is a shelf plate of an article placement shelf or a base plate of an article placement table,
The main component of the shelf board or the base plate is a transparent non-conductor,
The at least antenna pattern of each of the first and second antennas is composed of a wire conductor having a cross-sectional diameter of 0.5 mm or less. Reader antenna.   The said 1st and 2nd antenna is provided between a pair of glass plates mutually laminated | stacked by interposing an insulating layer between these, The any one of Claims 1-11 characterized by the above-mentioned. Antenna for readers as described in 1.   Each of the terminal portion of the first antenna and the terminal portion of the second antenna includes one and the other edge portions in the length direction of the antenna forming target member, and a back side edge portion in the width direction. The reader antenna according to claim 1, wherein the reader antenna is provided at any one edge selected from the inside.   An article mounting shelf with an antenna, comprising: a shelf board on which the reader antenna according to any one of claims 1 to 13 is formed as the antenna formation target member.   An article mounting table with an antenna, comprising: a base plate on which the reader antenna according to any one of claims 1 to 13 is formed as the antenna formation target member.

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