JP4548661B2 - RFID tag reading system - Google Patents

Description

  The present invention relates to an antenna for an article management shelf, and in particular, is configured by arranging antenna lines in a loop shape on the shelf board surface of an article management shelf in which articles attached with RFID tags are aligned and placed on the shelf board. The present invention relates to an antenna for an article management shelf.

  An article management shelf using an RFID tag is conventionally known (see, for example, Patent Documents 1 and 2). 8 is a perspective view showing the structure of a conventional example of an article management shelf, FIG. 9 is a diagram for explaining magnetism generated by the reader / writer shown in FIG. 8, and FIG. 10 is a loop by the reader / writer shown in FIG. FIG. 11 is a diagram for explaining the connection relationship for driving the antenna, FIG. 11 is a diagram for explaining the attachment state of the IC card (RFIC tag) and the resonance card to the book, and FIG. FIG. 13 is a diagram for explaining the relationship between the direction of magnetism generated by the antenna line of the loop antenna and the attachment direction of the IC card and the resonance card. FIG. 14 is a diagram for explaining reading of the IC card. 15 is a diagram showing a conventional example of an antenna switch.

  The article management shelf 500 of FIG. 8 has three shelf boards 51, 52, 53 inside the outer casing 50. Loop antennas 61, 62, 63 are arranged on the surfaces (upper surface or lower surface) of the shelf boards 51, 52, 53. Further, a reader / writer 70 and an antenna switch 79 are arranged on the upper surface of the outer casing 50. The reader / writer 70 is sequentially connected to the loop antennas 61, 62, 63 via the antenna switch 79. FIG. 15 shows a conventional example of the antenna switch 79. In this case, one of the switches 16a, 16b,... Is selected by a control signal from the reader / writer 70, and the selected switch is selected. A drive signal is output through the corresponding loop antenna.

  For example, when reading RFID information of articles on the shelf boards 51, 52, 53, the reader / writer 70 is connected to the loop antenna 61 via the antenna switch 79, and drives the loop antenna 61 to operate the shelf board. The RFID information of the article placed on 51 is read. After the reading by the loop antenna 61 is completed, the reader / writer 70 is switched to the loop antenna 62 via the antenna switch 79 and drives the loop antenna 62 to read the RFID information of the article placed on the shelf plate 52. . After the reading is completed, the reader / writer 70 is switched to the loop antenna 63 via the antenna switch 79, drives the loop antenna 62, reads the RFID information of the article placed on the shelf 53, and responds to the request. Repeat these operations.

  In the above example, the loop antennas 61 and 63 are one-loop, but the loop antenna 62 has a two-loop twisted 180 degrees near the center. In this case, as shown in FIG. 9A, when a current is passed only through the loop antenna 62, the magnetic φ1 or φ2 is generated in each loop. Since the generated magnets φ1 and φ2 cancel each other when passing through the loop antenna 63, the magnetism passing through the loop antenna 63 becomes zero, and the loop antenna 63 is not affected.

  The above is the same when a current is passed only through the loop antenna 63 as shown in FIG. 9B, and the magnetic φ0 generated by the loop antenna 63 passes through the loop antenna 62. The magnets φ1 and φ2 are generated in each loop of the loop antenna 62. However, since these magnets φ1 and φ2 cancel each other, the influence of magnetism passing through the loop antenna 62 becomes zero, and the loop antenna 62 is not affected at all. This relationship is the same for the loop antenna 61, and when the reader / writer 70 drives by switching one of the loop antennas 61, 62, and 63 sequentially via the antenna switch 79, the drive affects the others. Can be run independently without giving

  The relationship in which the loop antenna 61 and the reader / writer 70 are connected is shown in the circuit diagram of FIG. The loop antenna 61 is connected to the reader / writer 70 via a tuning circuit 71, a coaxial cable 72, and a connector 73. The tuning circuit 71 is composed of a transformer 71a and a capacitor 71b disposed on the circuit board, and resonates with the loop antenna 61. In this case, as another connection method, up to the tuning circuit 71 is integrated with the reader / writer 70 and is configured to be separated from the loop antenna 61, both ends of the loop antenna 61 being separated, and tuning It is also preferable to provide connection terminals at both ends of the circuit 71 so as to be detachable.

Further, when the article placed on the shelf board of the article management shelf 500 in FIG. 8 is the book 80, normally, from the front to the rear so that the spine 81 of the book 80 comes to the front as shown in FIG. It shall be put in (towards the depth direction). In this case, as shown in FIG. 11, there are many examples in which an IC card 82 is attached to the back cover 81 and a resonance card 83 is attached to the cover. As shown in FIG. 12, the IC card 82 includes an IC chip 82a and a card antenna 82b. Under these circumstances, when a book with an IC card 82 attached to the spine is aligned on the shelf as shown in FIG. 13, the magnetic field generated by the loop antenna is generated in the circumferential direction of the antenna line. To do. Therefore, the magnetic field intersects at right angles to the plane of the IC card 82, that is, the card antenna 82b extending parallel to the plane, which is advantageous for reading and writing by the reader / writer 70.
JP 2004-140513 A JP 2001-34811 A

  However, the article to which the IC card (RFID tag) is attached becomes thin, and the IC card to be attached to it must be attached not to the back cover but to the cover (the surface to which the resonance card is attached in FIG. 13). In this case, there is a problem that the magnetic field from the loop antenna does not easily pass through the card antenna, and reading / writing of the reader / writer cannot be performed satisfactorily. The relationship between the antenna line and the IC card will be briefly described with reference to FIG. 14 viewed from above. Normally, the direction of the antenna line and the IC card plane is the same, but when the antenna line is perpendicular to the IC card as shown in FIG. 14A, the magnetic field generated by the antenna line passes through the IC card. It becomes difficult to do. However, if the magnetic field passes smoothly through the IC card as shown in FIG. 14B, the reader / writer can read and write well.

    The present invention has been made to solve the above-described problems. An article to which an IC card (RFID tag) is attached becomes a thin object, and the IC card attached to the IC card (RFID tag) is attached to the cover (not shown in FIG. 13). Provided is an article management shelf antenna that allows a magnetic field from a loop antenna to pass through a card antenna even if it has to be attached to a surface on which a resonance card is attached, and that allows a reader / writer to read and write well. For the purpose.

  In order to solve the above-described problems, the antenna for an article management shelf according to the present invention has a looped antenna line on the shelf board surface of an article management shelf in which articles attached with RFID tags are aligned and placed on the shelf board. The antenna line is arranged so that the magnetic field generated from at least a part of the antenna line passes through the RFID tag obliquely.

  According to such a configuration, when a thin article with an RFID tag attached is aligned and placed on a shelf board of an article management shelf, even if the RFID tag is parallel to the depth direction, the antenna line Since the magnetic field passes obliquely through the RFID tag, reading and writing of the reader / writer can be performed satisfactorily. Even in the case of a normal article, since the magnetic field of the antenna line passes through the RFID tag obliquely, there is no problem in reading and writing by the reader / writer. As one simple method, when the articles are aligned on the shelf board of the article management shelf, it is conceivable that the antenna lines passing through the positions where the RFID tags are arranged are inclined so as to pass diagonally.

  The present invention also relates to an antenna for an article management shelf configured by arranging antenna lines in a loop shape on the surface of an article management shelf on which articles attached with RFID tags are arranged and placed on the shelf board. The antenna line has a first side and a second side facing each other, a third side and a fourth side facing each other, a third side at one end of the first side, and the other side of the first side. A fourth side is provided at the end, a third side is provided at one end of the second side, a fourth side is provided at the second other end, and the length of the first side is the first side. It is characterized by being shorter than the length of 2 sides.

  Furthermore, the present invention is characterized in that a plurality of the loop antennas are independently provided on the shelf plate, a part of the independent antennas is driven, and an antenna adjacent to the driven antenna is not driven.

  As described in detail above, according to the present invention, when a thin article attached with an RFID tag is aligned and placed on a shelf board of an article management shelf, the RFID tag is parallel to the depth direction (for example, FIG. 14 (a)), since the magnetic field of the antenna line passes through the RFID tag obliquely, reading and writing of the reader / writer can be performed satisfactorily. Even in the case of a normal article, since the magnetic field of the antenna line passes through the RFID tag obliquely, there is no problem in reading and writing by the reader / writer.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of an article management shelf antenna according to the present invention. FIG. 2A is a perspective view showing a second embodiment of the article management shelf antenna according to the present invention. FIG. 2B is a plan view of FIG. 3 to 7 are plan views showing Embodiments 3 to 7 of the article management shelf antenna according to the present invention.

  In the first embodiment shown in FIG. 1, a one-loop antenna 21 is arranged on the shelf board 11. Of the four antenna lines constituting the loop antenna 21, the antenna line extending along the upper edge of the shelf 11 shown in FIG. 1 is referred to as a rear antenna line 21b. The reason for such a designation is that when the shelf board 11 shown in FIG. Because. For the sake of clarity, the article is placed from the front part of the shelf board 11 to the rear part (in the depth direction) after the above-described shelf board 11 is assembled to the article management shelf. In this case, the RFID tag (or IC card) attached to the article is assumed to be positioned in front of the shelf board 11 so as to be on the antenna line 21a.

  The above-mentioned naming method is also applied to the antenna lines extending along the lower edge, the left edge, and the right edge of the shelf board 11 shown in FIG. 1, and each antenna line includes a front antenna line 21a and a left antenna. These are referred to as a line 21c and a right antenna line 21d. These rear antenna line 21b, left antenna line 21c, and right antenna line 21d are arranged so as to be parallel to the outer edge of the shelf board 11 in the same manner as the conventional one, but the front antenna line 21a is It is arranged so as to be inclined with respect to the front edge of the shelf board 11 in accordance with the position of the RFID tag of the article to be placed.

  That is, in other words, the structure of only the loop antenna 21 is composed of four linear antenna lines 21a, 21b, 21c, and 21d arranged in a quadrilateral shape on a plane. In this case, a left antenna line 21c and a right antenna line 21d extend at right angles from both ends of the rear antenna line 21b. However, the left antenna line 21c is shorter than the right antenna line 21d. Further, the front antenna line 21a extends so as to connect the front ends of the left antenna line 21c and the right antenna line 21d, and is inclined with respect to the rear antenna line 21b.

  As described above, the front antenna line 21a is arranged so as to be oblique to the front edge of the shelf board 11, so that the direction of magnetism generated by the front antenna line 21a is changed to the depth direction (of the shelf board 11). It is not parallel to the direction from the front part to the rear part, and has a constant inclination angle with respect to the depth direction. Therefore, when the article is placed on the article management shelf, even if the RFID tag attached to the article is aligned along the front edge in parallel with the depth direction of the article management shelf, the front antenna line 21a The generated magnet intersects the antenna development surface of the RFID tag and passes through the antenna of the RFID tag, so that the reader / writer can exchange signals with the RFID tag through the loop antenna 21.

  In this example, the antenna line arrangement has been described in relation to the outer edge of the shelf so that the explanation can be easily understood. However, the arrangement of the antenna line is not necessarily related to the outer edge, and is not limited to a straight line. By placing the magnet line generated by the antenna line related to reading when the article is placed on the shelf so as to intersect the antenna deployment surface of the RFID tag attached to the article at a predetermined angle It is important to provide the above-mentioned magnetic characteristics.

  In Embodiment 2 of FIG. 2, three loop antennas 25, 26, and 27 form a loop in the vertical direction on the shelf board 12, and are arranged so as to be oblique to the depth direction and parallel to each other. Has been. In this case, since the loop antennas 25, 26, and 27 are independent from each other, the reader / writer determines which of the loop antennas 25, 26, and 27 is driven by an antenna switch (the same as the conventional example). You can select freely via

With respect to the above-described driving, for example, when reading RFID information of articles on the shelf board 12, the reader / writer is connected to, for example, the loop antenna 25 via the antenna switch, and drives the connected loop antenna 25. RFID information of an article placed on the shelf 12 (on the loop antenna 25) is read. After the reading by the loop antenna 25 is completed, the reader / writer is connected to the loop antenna 26 via the antenna switch, and drives the loop antenna 26 to place the RFID of the article placed on the shelf 12 (on the loop antenna 26). Read information. After the reading is completed, the reader / writer is connected to the loop antenna 27 via the antenna switch, and drives the loop antenna 27 to read the RFID information of the article placed on the shelf board 12 (on the loop antenna 27). .
Alternatively, only the loop antenna 26 may be driven without using the antenna switch, and RFID information may be read from the loop antennas 25 and 27. By driving the antenna 26, the antennas 25 and 27 resonate and the RFID on the antennas 25 and 26 can be read.

  In the third embodiment of FIG. 3, the rear antenna line 33c of the loop antenna 33 formed on the shelf board 13 extends straight along the rear edge, but the front antenna line is the apex at the center. The antenna lines 33a and 33b are inclined on both sides so as to form a mountain shape. Compared to the case of FIG. 1, the antenna lines 33a and 33b can be flexibly adapted to increase the inclination angle. In Embodiment 4 of FIG. 4, the front part of the loop antenna 34 formed on the shelf board 14 is formed to be three mountain-shaped antenna lines 34a, 34b, and 34c. In this case, the angle of inclination of the antenna line can be adjusted more flexibly than in FIG.

  In the fifth embodiment of FIG. 5, three loop antennas 35, 36, and 37 are formed on the shelf board 15 so as to form a loop in the horizontal direction and obliquely parallel to the depth direction. These loop antennas 35, 36, and 37 are obtained by horizontally arranging loop antennas 35, 36, and 37 at positions corresponding to the loop antennas 25, 26, and 27 of the second embodiment shown in FIG. Also in this case, since the loop antennas 35, 36, and 37 are independent from each other, the reader / writer can freely select which of the loop antennas 35, 36, and 37 is driven via the antenna switch. .

In connection with the driving of FIG. 5 described above, for example, when reading the RFID information of the article on the shelf board 15, the reader / writer is connected to, for example, the loop antenna 35 via the antenna switch, and connected to the loop. The antenna 35 is driven to read the RFID information of the article placed on the shelf board 15. After the reading by the loop antenna 35 is completed, the reader / writer is connected to the loop antenna 36 via the antenna switch, and drives the loop antenna 36 to read RFID information of the article placed on the shelf board 15. After the reading is completed, the reader / writer is connected to the loop antenna 37 via the antenna switch, and drives the loop antenna 37 to read the RFID information of the article placed on the shelf board 15.
Alternatively, only the loop antenna 36 may be driven without using the antenna switch, and RFID information may be read from the loop antennas 35 and 37. By driving the antenna 36, the antennas 35 and 37 resonate, and the RFID on the antennas 35 and 36 can be read.

  In Embodiment 6 of FIG. 6, two antenna lines 41 and 42 extending like a sawtooth wave parallel to the shelf plate 16 are connected at the tip to form a loop antenna 40. In this case, since any one of the antenna lines 41 and 42 works more strongly, the probability of malfunction is lowered.

  In the seventh embodiment shown in FIG. 7, a loop antenna 45 having the same shape as the loop antenna 21 shown in FIG. Is formed. Also in this case, since any one of the loop antennas 45 and 46 works more strongly, the probability of malfunction is reduced.

In the eighth embodiment shown in FIG. 8, the antenna lines 49 and 50 are crossed from the end portions of the antenna lines 47 and 48 parallel to each other to the end portions of the other antenna lines.
Thereby, since it can cross | intersect with the antenna surface of RFID diagonally, RFID information can be read.

It is a top view which shows Embodiment 1 of the antenna for article management shelves of this invention. (A) is a perspective view which shows the structure of Embodiment 2 of the antenna for article management shelves of this invention. (B) is a top view of (a). It is a top view which shows Embodiment 3 of the antenna for articles | goods management shelves of this invention. It is a top view which shows Embodiment 4 of the antenna for articles | goods management shelves of this invention. It is a top view which shows Embodiment 5 of the antenna for articles | goods management shelves of this invention. It is a top view which shows Embodiment 6 of the antenna for articles | goods management shelves of this invention. It is a top view which shows Embodiment 7 of the antenna for articles | goods management shelves of this invention. It is a top view which shows Embodiment 8 of the antenna for articles | goods management shelves of this invention. It is a block diagram which shows the prior art example of an article | item management shelf. (A), (b) is a figure for demonstrating operation | movement of the loop antenna used for the article | item management shelf of FIG. It is a circuit diagram for demonstrating the connection relation of the reader / writer of FIG. 8, and a loop antenna. FIG. 9 is a diagram for explaining how an IC card is attached when a book is placed on the article management shelf in FIG. 8. It is a figure for demonstrating the internal structure of the IC card used in FIG. (A), (b) is a figure for demonstrating the relationship between the IC card attached to the book of FIG. 11, and the magnetic field which a loop antenna produces | generates. (A) is a figure for demonstrating the relationship between the antenna line of the conventional loop antenna, the magnetic field which it generate | occur | produces, and an IC card from upper direction. (B) is a diagram for explaining the idea that, if (a) is modified and the magnetic field generated by the antenna line passes obliquely through the IC card, reading / writing by the reader / writer can be performed satisfactorily. It is a figure which shows the prior art example of an antenna switch.

Explanation of symbols

11, 12, 13, 14, 15, 16, 17 Shelf, 21, 25, 26, 27, 33, 34, 35, 36, 37, 40, 45, 46 Loop antenna, 21a, 21b, 21c, 21d, 33a, 33b, 33c, 34a, 34b, 34c, 34d, 41, 42 Antenna lines.

Claims (3)

The RFID tag that is attached to the article, using the article management shelf antenna for the loop antenna was constructed placed on the shelf plate surface of the article management shelf for placing on top of a rectangular shelf plate by aligning the article RFID tag reading system
The loop antenna is composed of four antenna lines parallel to the surface of the shelf plate, the first and second antenna lines face each other, the third and fourth antenna lines face each other, and the first antenna line A third antenna line is provided at one end, a fourth antenna line is provided at the other end of the first antenna line, and a third antenna line is provided at one end of the second antenna line. A fourth antenna line is provided at the end, the third antenna line is parallel to the first side of the shelf, and the fourth antenna line is against the second side facing the first side. Non-parallel,
The article attached with the RFID tag is located between the first antenna line and the second antenna line, the antenna surface of the RFID tag being perpendicular to the surface of the loop antenna, Aligned so as to be parallel to the direction from one side to the second side,
It said loop antenna is disposed such that the fourth antenna line or we generated magnetic field you passes antenna of the RFID tag obliquely
An RFID tag reading system characterized by the above . The RFID tag reading system according to claim 1, wherein
In addition to the loop antenna, a second loop antenna having a shape in which the left and right sides of the loop antenna are reversed when the direction of the first side of the shelf plate is the left and right direction is positioned so as to overlap the loop antenna. Prepared,
An RFID tag reading system , wherein when driving the loop antenna, the antenna to be driven is switched so as not to drive the second loop antenna . The RFID tag attached to the article is read using an article management shelf antenna configured by arranging a loop antenna on the shelf surface of the article management shelf where the articles are aligned and placed on a rectangular shelf board. An RFID tag reading system,
The loop antenna is composed of four antenna lines parallel to the surface of the shelf, the first and second antenna lines face each other, and a third antenna line is connected to one end of the first antenna line. A fourth antenna line is provided at the other end of the second antenna line, a third antenna line is provided at one end of the second antenna line, and a fourth antenna line is provided at the other end of the third antenna line, The third and fourth antenna lines are formed to cross each other,
The article attached with the RFID tag is located between the first antenna line and the second antenna line, the antenna surface of the RFID tag being perpendicular to the surface of the loop antenna, Aligned so as to be parallel to the direction from one side to the second side,
The RFID tag reading system , wherein the loop antenna is arranged so that a magnetic field generated from the third and fourth antenna lines obliquely passes through the antenna of the RFID tag .

Images