JP2008206696A - Shelf board and showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shelf board and a showcase suitable for displaying merchandise to which an RFID tag is stuck. <P>SOLUTION: A through hole 3 for intercepting a flow passage of an eddy current by electromagnetic waves from an antenna 200 generated when a current is applied to the antenna 200 for communicating with the RFID tag placed on the top is formed in a merchandise shelf board 2 formed of metal-made plate-like member. Thus, the generation of an eddy current is reduced, thereby preventing reduction in communication range due to the generation of an eddy current. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a merchandise display shelf such as a showcase and a shelf board thereof, and more particularly, to a merchandise display shelf and a shelf board suitable for reading an RFID tag attached to a merchandise.

In recent years, a system has been proposed in which an RFID tag is attached to a product to manage the stock, distribution route, etc. of the product. For example, the device described in Patent Document 1 has an RFID tag attached to a rental video stored in a bookcase-like storage case. A shelf antenna for communication with the RFID tag is arranged on each shelf of the storage case. Each shelf antenna is connected to a controller corresponding to a reader / writer for the RFID tag. Furthermore, the controller is connected to the host computer. In such a system, rental video stock is managed by a host computer for each shelf of each storage case.
JP 2001-118037 A

  However, in the system as described above, there is a problem that reading accuracy of the RFID tag is lowered when a metal material is used as a shelf. The reason is as follows. When the magnetic flux formed by the shelf antenna passes through the shelf plate, an eddy current is generated in the shelf plate. This eddy current generates a magnetic flux in the opposite direction to the magnetic flux formed by the shelf antenna. Thereby, the magnetic flux formed by the shelf antenna is weakened, and as a result, the communication range of the shelf antenna is narrowed.

  Therefore, when a metal material is used for the shelf, there is a problem that complicated adjustment work such as increasing the output power of the controller or adjusting the impedance is necessary and the power consumption increases. Further, depending on the controller, there is a case where sufficient reading accuracy cannot be ensured even if the adjustment process is performed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shelf board and a showcase suitable for displaying products to which an RFID tag is attached.

  In order to achieve the above object, in the present application, a shelf plate made of a metal plate-like member used for a merchandise display shelf such as a showcase, which is energized to an antenna for communication with an RFID tag placed on the upper surface. A through hole is formed that cuts off the flow path of eddy current due to electromagnetic waves generated from the antenna.

  According to the present invention, the path of eddy current generated when the electromagnetic wave radiated from the antenna passes through the shelf is blocked by the through-hole formed in the shelf. Therefore, since the generation of eddy current is reduced, it is possible to prevent the communication range from being reduced due to the generation of eddy current. Therefore, the shelf board according to the present invention is suitable for displaying products with RFID tags attached.

  As an example of a preferred aspect of the present invention, in the present application, the through hole is formed at least directly below or in the vicinity of the antenna element when an antenna including a loop antenna is placed on the upper surface. Suggest a thing.

  According to the present invention, since the through hole is formed immediately below or in the vicinity of the antenna element that is estimated to have high eddy current strength, the generation of eddy current can be efficiently reduced. As a specific aspect of the present invention, the through hole includes a long hole formed in a direction orthogonal to the antenna element.

  As an example of a preferred aspect of the present invention, in the present application, the through hole is formed radially from the center position of the magnetic flux when the antenna including the loop antenna is placed on the top surface of the shelf board. Suggest features.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the eddy current which generate | occur | produces just under the center of the magnetic flux of a loop antenna and its vicinity can be reduced efficiently.

  As described above, according to the present invention, the path of eddy current generated when the electromagnetic wave radiated from the antenna passes through the shelf is blocked by the through hole formed in the shelf. Therefore, since the generation of eddy current is reduced, it is possible to prevent the communication range from being reduced due to the generation of eddy current. Therefore, the shelf board according to the present invention is suitable for displaying products with RFID tags attached.

(First embodiment)
A showcase according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an inventory management system including a showcase, and FIG. 2 is a perspective view of a product shelf.

  The inventory management system according to the present embodiment reads the unique number of the RFID tag 11 from the RFID tag 11 attached to the product 10 displayed in the showcase 1, and manages the unique number with the computer 50. Inventory management. In this embodiment, it is assumed that the RFID tag 11 of the HF band (13.56 MHz band) is used.

  As shown in FIG. 1, the showcase 1 includes a multi-stage product shelf 2 for displaying the product 10 and a cooling mechanism (not shown) for cooling the product 10. Since the cooling mechanism is the same as that conventionally known, the description thereof is omitted here. An antenna unit 200 for communicating with the RFID tag 11 of the displayed product 10 is provided on the upper surface of each product shelf 2. For example, two antenna units 200 are arranged in parallel on the left and right sides of the top surface of each product shelf 2. The showcase 1 also includes a control unit 100 connected to each antenna unit 200 on a one-to-one basis, and a central control device 300 that performs central control of each control unit 100. The control unit 100 reads a unique number preset in the tag from the RFID tag 11 using each antenna unit 200 to be connected. The centralized control device 300 totals the unique numbers of the RFID tags 11 read by the control units 100 and transmits the totaled data to the computer 50 installed in the store.

  As shown in FIG. 2, the antenna unit 200 includes a coil antenna 202 inside a thin box-shaped housing 201. In this embodiment, the coil antenna 202 is made of a printed wiring board. That is, the antenna element of the coil antenna 202 is composed of a pattern conductor formed on the printed wiring board. In the present embodiment, the coil antenna 202 is a rectangular one-turn coil. The dimensions of the coil antenna 202 were 207 mm long and 120 mm wide, the width of the antenna element was 1 mm, and the thickness was 0.035 mm. The antenna unit 200 is placed on the top surface of the product shelf 2 as shown in FIGS. 1 and 2.

  The product shelf 2 of the showcase 1 is made of a metal plate member. A plurality of through holes 3 are formed in the product shelf 2. As shown in FIG. 2, the through hole 3 is formed immediately below or near the antenna element of the coil antenna 202 when the antenna unit 200 is placed on the upper surface. In FIG. 2, the alternate long and short dash line drawn on the product shelf 2 indicates the position of the antenna element. In the present embodiment, the through hole 3 is formed in a square long hole shape having a length of 45 mm and a width of 10 mm. Each through-hole 3 is formed side by side in the width direction at a predetermined interval (1 mm in the present embodiment). Each through hole 3 is formed in a direction orthogonal to the direction in which the antenna element extends.

  With respect to the product shelf 2 of such a showcase 1, when the eddy current generation state was measured by computer simulation, the strength of the eddy current generated immediately below and in the vicinity of the antenna element is that the through hole 3 is not formed. It was confirmed that the amount was significantly reduced. This is because the eddy current path is blocked by the through hole 3. Therefore, according to the product shelf 2 of the showcase 1 according to the present embodiment, since a large number of through holes 3 are formed at the position closest to the antenna element of the coil antenna 202, an eddy current generated immediately below the antenna element. The strength of can be reduced. Thereby, the reduction of the communication range due to the generation of eddy current can be prevented.

  FIG. 3 shows a modification of the product shelf 2 according to the present embodiment. In FIG. 3, the alternate long and short dash line indicates the position of the antenna element. In the product shelf 2, a large number of round hole-shaped through holes 4 are formed immediately below and in the vicinity of the antenna element. The same effect as described above can be obtained by such a product shelf 2.

  FIG. 4 shows a modification of the product shelf 2 according to the present embodiment. In FIG. 4, the alternate long and short dash line indicates the position of the antenna element. In the commodity shelf board 2, a large number of through-holes 5 having a round hole shape are formed immediately below and in the vicinity of the antenna element and inside the coil antenna 202. The same effect as described above can be obtained by such a product shelf 2. In addition, as a modified example that can obtain the same effect, a through hole may be formed in the entire region of the product shelf 2.

(Second Embodiment)
A showcase according to a second embodiment of the present invention will be described with reference to the drawings. The difference between the showcase according to the present embodiment and the first embodiment is the position and shape of the through holes formed in the product shelf 2. Only the differences will be described below.

  FIG. 5 shows a top view of the product shelf 2 according to the present embodiment. In FIG. 5, the alternate long and short dash line indicates the position of the antenna element. In the product shelf 2, slit-like through holes 6 are formed radially with the center position of the magnetic flux of the coil antenna 202 as the center. As shown in FIG. 5, the length of the through-hole 6 may be formed so as not to exceed the position immediately below the antenna element, or may be formed so as to exceed it.

  According to the product shelf 2 of the showcase 1 according to the present embodiment, the eddy current path generated around the center position of the coil antenna 202 is blocked by the through-hole 6, thereby reducing the strength of the eddy current. it can. Thereby, the reduction of the communication range due to the generation of eddy current can be prevented.

  Although the first and second embodiments of the present invention have been described in detail above, the present invention is not limited to this. For example, as shown in FIGS. 6 and 7, both the through hole 3 or the through hole 4 according to the first embodiment and the through hole 6 according to the second embodiment are formed on the commodity shelf 2. You may make it do.

  In the first embodiment, a rectangular hole or a round hole is exemplified as the shape of the through hole. In the second embodiment, the radially formed through hole is exemplified, but other shapes may be used. Good. That is, the shape of the through hole is not limited as long as the eddy current path is interrupted.

  Moreover, in the said embodiment, although nothing is filled in each through-hole, you may make it fill a member from a viewpoint of improving the intensity | strength of a goods shelf board. In this case, a non-conductive member is used as the filling member in order to block the eddy current path.

  Moreover, in the said embodiment, although the loop antenna was illustrated as an antenna for communication with RFID tag 11, this invention is applicable even if it is another antenna.

  Moreover, in the said embodiment, although the showcase which has a cooling mechanism was illustrated as an example of the goods display shelf which displays the goods 10 to which the RFID tag 11 was affixed, it is a general shelf which does not have a cooling mechanism. The present invention can also be applied.

Configuration diagram of inventory management system using RFID tags The perspective view of the goods shelf board concerning a 1st embodiment Top view of a product shelf according to another example of the first embodiment Top view of a product shelf according to another example of the first embodiment Top view of a product shelf according to another example of the first embodiment Top view of product shelf board according to the second embodiment Top view of a product shelf according to another example of the second embodiment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Showcase, 2 ... Product shelf board, 3, 4, 5, 6 ... Through-hole.

Claims (5)

A shelf plate made of a metal plate-like member used for a product display shelf such as a showcase,
A shelf plate, wherein a through-hole is formed to block a flow path of eddy current due to electromagnetic waves from the antenna generated when the antenna for communication with the RFID tag placed on the upper surface is energized. The shelf plate according to claim 1, wherein the through hole is formed at least directly below or in the vicinity of the antenna element when an antenna including a loop antenna is placed on the upper surface. The shelf plate according to claim 2, wherein the through hole includes a long hole formed in a direction orthogonal to the antenna element. The shelf plate according to claim 1, wherein the through hole is formed radially from the center position of the magnetic flux when an antenna including a loop antenna is placed on the top surface of the shelf plate. In a showcase provided with a shelf board having a metal plate member,
The shelf plate is formed with a through hole that blocks a flow path of eddy current due to electromagnetic waves from the antenna generated when the antenna for communication with the RFID tag placed on the upper surface is energized. Showcase.

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