JP2011087287A - Article management device and article management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for securely detecting an article disposed in an article arrangement space taken out of the article arrangement space by reading an RF tag using a radio wave. <P>SOLUTION: An article management device includes an antenna including at least one array antenna constituted by arraying a plurality of antenna elements in one body which can radiate a radio wave having an intensity distribution capable of providing radio communication with an RF (Radio Frequency) tag disposed in a predetermined detection object range substantially matching an article arrangement space where an article is arranged on the whole when the array antenna is arranged at a corresponding position; an electric power supply unit configured to supply electric power to the plurality of antenna elements constituting the array antenna in one body in array antenna units; and a communication unit configured to transmit and receive signals to and from the RF tag attached to the article arranged in the article arrangement space. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an RF (Radio Frequency) tag reading technique, and more particularly, to a technique for detecting the loading and unloading of an article with respect to a predetermined area.

  In the past, efforts have been made to collect and analyze information that the products placed on the product display shelves have been picked up by customers, and use them for store management and product planning to generate sales. For this purpose, for example, an RF tag is attached to a product and displayed on a product display shelf, and it is detected that the product is taken out from the product display shelf by an antenna of a reader (reader / writer) that reads the tag. Yes. Thereby, when it is detected that the product is taken out from the shelf, it is possible to collect information that the customer has taken out the product from the product display shelf and picked it up.

  As a method for detecting that a product placed on a product display shelf has been taken out from the product shelf, for example, methods disclosed in Patent Documents 1 to 3 are known.

  In Patent Document 1, a rectangular antenna is embedded in the front end of each shelf of the product display shelf, and the product is taken out from the shelf without reading the RF tag attached to the product when the product is stored in the shelf. A method of detecting that a customer has picked up a product by reading an RF tag attached to the product is sometimes described.

  Further, in Patent Document 2, a reader antenna is arranged on each shelf board of a product display shelf, an RF tag attached to a product placed on the shelf is read, and when the product is picked up, the communication range is reached. A method for detecting that a product has been picked up by using the fact that reading of the RF tag is not performed due to disconnection is described.

  In addition, transparent glass shelves are often used as merchandise display shelves for displaying clothing, decorations, and the like in order to make the merchandise bright and beautiful. In Patent Document 3, the product is managed using an antenna that is almost transparent as a reader antenna that reads an RF tag attached to the product so as not to impair the appearance of the transparent glass display shelf. How to do is described.

  The communication between the RF tag and the reader (or reader / writer) antenna as described above is widespread of RF tags using radio waves in the UHF band because the communication distance is relatively long and the price can be suppressed. Is progressing. In the case of an RF tag that uses 13.56 MHz radio waves that are not in the UHF band, the reader antenna must be brought close to the RF tag in order to perform communication by electromagnetic induction. In the case of an RF tag that uses UHF band radio waves, Since communication is performed by radio waves radiated into space, there is an advantage that reading is possible even at a distance of 2 to 3 m.

  However, when UHF band radio waves are used for communication between the RF tag and the antenna, the methods described in Patent Documents 1 to 3 described above have the following problems.

  First, in the method shown in Patent Document 1, the reach of radio waves is 20 cm to 40 cm. However, when radio waves in the UHF band are used, it is difficult to limit the reach of radio waves to the above range. Is difficult to realize using radio waves in the UHF band.

  In the method shown in Patent Document 2, it is assumed that the 13.56 MHz band is used as the frequency of the radio wave used for communication, and when the UHF band radio wave is used instead, the RF tag is close to the reader antenna. It is difficult to make reading possible only with this. It is also difficult to limit the radiation range of radio waves. Therefore, with this method, it is difficult to use UHF band radio waves.

  In addition, the methods disclosed in Patent Documents 1 and 2 also have a problem that the aesthetic appearance of the shelf is impaired by the installed antenna.

  In the method shown in Patent Document 3, since it is a transparent antenna, the appearance of the shelf can be maintained to some extent. However, the configuration of the antenna that can use the UHF band radio wave is not shown, and even if it can be used, it is difficult to limit the radiation range, so this method also uses the UHF band radio wave. It is difficult.

  The present invention has been made to solve the above-described problems, and reliably detects that an article placed in the article placement space has been taken out of the article placement space by reading an RF tag using radio waves. The purpose is to provide technology.

  In order to solve the above problems, an embodiment of the present invention is an antenna including at least one array antenna configured by integrally arranging a plurality of antenna elements, and the array antenna is disposed at a corresponding position. In the case where the antenna is a radio wave having an intensity distribution that enables wireless communication with an RF (Radio Frequency) tag arranged within a predetermined detection target range that substantially coincides with the article arrangement space in which the article is arranged, as a whole An antenna that can radiate the antenna, a power supply unit that supplies power to each of a plurality of antenna elements that integrally form the array antenna, and the antenna is disposed in the article placement space via the antenna. The present invention relates to an article management apparatus including a communication unit that transmits and receives signals to and from an RF tag attached to an article to be processed.

  One embodiment of the present invention is an antenna including an article arrangement shelf having an article arrangement space in which articles can be arranged, and at least one array antenna configured by integrally arranging a plurality of antennas, When the array antenna is arranged at a corresponding position, the antenna as a whole can wirelessly communicate with an RF tag arranged in a predetermined detection target range that substantially matches the article arrangement space in which the article is arranged. An antenna capable of radiating radio waves having an intensity distribution, a power supply unit for supplying power to each of a plurality of antenna elements integrally constituting the array antenna, and the article via the antenna The present invention relates to an article management system including a communication unit that transmits and receives signals to and from an RF tag attached to an article arranged in an arrangement space.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which detects reliably that the articles | goods arrange | positioned in the article | item arrangement | positioning space were taken out from the article | item arrangement | positioning space by reading the RF tag using an electromagnetic wave can be provided.

It is the schematic for demonstrating the structure of the goods management apparatus which is an example of the article | item management apparatus by 1st Embodiment. It is the schematic diagram which looked at the display shelf by which the antenna by 1st Embodiment was arrange | positioned in the predetermined position from upper direction. It is a block diagram for demonstrating the power supply method with respect to the array antenna which comprises the antenna by 1st Embodiment. It is a perspective view explaining the structure of the antenna element which comprises the antenna by 1st Embodiment. It is a figure which shows the arrangement | sequence of an antenna element. It is a figure which shows the radiation pattern at the time of supplying electric power simultaneously to the antenna element of the array antenna shown in FIG. 5, and radiating | emitting a radio wave. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of the radiation pattern shown in FIG. It is the schematic diagram which looked at the display shelf by which the array antenna by 2nd Embodiment was arrange | positioned by the predetermined arrangement | sequence at the predetermined position from the upper direction. It is the schematic diagram which looked at the display shelf by which the array antenna by 3rd Embodiment was arrange | positioned by the predetermined arrangement | sequence at the predetermined position from the upper direction. It is a figure which shows the arrangement | sequence of an antenna element. It is a figure which shows the radiation pattern at the time of supplying electric power simultaneously to the antenna element of the array antenna shown in FIG. 11, and radiating | emitting a radio wave. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of the radiation pattern shown in FIG. It is the schematic diagram which looked at the display shelf by which the array antenna by 4th Embodiment was arrange | positioned by the predetermined arrangement | sequence at the predetermined position from the upper direction. It is a figure which shows the arrangement | sequence of an antenna element. It is a figure which shows the radiation pattern at the time of supplying electric power simultaneously to the antenna element of the array antenna shown in FIG. 16, and radiating | emitting a radio wave. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern at the time of supplying electric power equally to each antenna element of an array antenna. It is the schematic diagram which piled up and showed the radiation pattern shown in FIG. 20 on the display shelf. It is the schematic diagram which looked at the display shelf with which the array antenna was arrange | positioned in the predetermined position from upper direction. It is a block diagram for demonstrating the supply method of the electric power with respect to the antenna element which comprises an array antenna. It is a schematic diagram which shows the arrangement | sequence of an array antenna. It is a figure which shows the radiation pattern at the time of supplying electric power to the antenna element of the array antenna shown in FIG. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of the radiation pattern shown in FIG. It is the figure which looked at the display shelf which shows the relationship between a display shelf, the radiation pattern of an electromagnetic wave, and the taking-out position of goods from the transversal direction. It is a figure which shows the radiation pattern at the time of supplying electric power with another predetermined power ratio to the antenna element of the array antenna shown in FIG. 23, and radiating | emitting a radio wave. It is a figure which shows the radiation pattern at the time of supplying electric power with another predetermined power ratio to the antenna element of the array antenna shown in FIG. 23, and radiating | emitting a radio wave. It is a figure which shows the radiation pattern at the time of supplying electric power with another predetermined power ratio to the antenna element of the array antenna shown in FIG. 23, and radiating | emitting a radio wave. It is the schematic diagram which looked at the display shelf with which the array antenna was arrange | positioned in the predetermined position from upper direction. It is a block diagram for demonstrating the supply method of the electric power with respect to the antenna element which comprises an array antenna. It is a figure which shows a radiation pattern at the time of supplying electric power to the antenna element of the array antenna shown in FIG. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a schematic diagram which shows the arrangement | sequence of an array antenna. It is a figure which shows the radiation pattern at the time of supplying electric power to the antenna element of the array antenna shown in FIG. It is a figure which shows the radiation pattern in yz plane of the radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of the radiation pattern shown in FIG. It is the schematic diagram which looked at the display shelf with which the array antenna was arrange | positioned in the predetermined position from upper direction. It is a schematic diagram which shows the arrangement | sequence of an array antenna. It is the schematic diagram which looked at the display shelf with which the array antenna was arrange | positioned in the predetermined position from upper direction.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram for explaining the configuration of a product management apparatus 1 which is an example of an article management apparatus according to the present embodiment.

  The merchandise management apparatus 1 of the present embodiment detects that the merchandise 14 has been taken out from the display shelf 12 by detecting an RF (Radio Frequency) tag 10 attached to the merchandise 14 by radio waves radiated from the antenna 2. It is a possible device. Such a merchandise management apparatus 1 can be used in, for example, a clothing store, and develops merchandise based on information that the merchandise has been picked up by the customer or not picked up by the customer. And store operations.

  The product management apparatus 1 of this embodiment includes an antenna 2 that is an array antenna, a power supply device 4 that supplies power to a plurality of antenna elements that constitute the array antenna at the same time, and reading processing of an RF tag 10 attached to the product. And a communication device 6 for controlling. The communication device 6 is connected to a computer 8 that manages information acquired by the communication device 6.

  It should be noted that the display shelf 12 that is a target for detecting the insertion and removal of products by the product management device 1 of the present embodiment has a rectangular placement surface in which one side of the surface on which the product is placed is longer than the other side. Are provided in a plurality of stages. Therefore, the space in which the products on the display shelf 12 are arranged has a rectangular parallelepiped shape excluding a cube.

  Hereinafter, each apparatus which comprises the merchandise management apparatus 1 is demonstrated based on FIGS. FIG. 2 is a schematic view of the display shelf 2 in which the antenna 2 is disposed at a predetermined position as viewed from above. FIG. 3 is a block diagram for explaining a method of supplying power to the array antenna constituting the antenna 2. FIG. 4 is a perspective view illustrating the configuration of the antenna element 20 included in the antenna 2.

  First, the antenna 2 of the commodity management apparatus 1 is, for example, an array antenna in which four antenna elements 20 shown in FIG. 4 are integrally arranged in one row. And the antenna element 20 which comprises the antenna 2 can use the antenna element comprised by arrange | positioning the radiation element 20a on the upper surface of the board | substrate 20b, and arrange | positioning the ground board 20c on the back side of the board | substrate 20b, for example. A feed point 20d is formed at a position shifted from the center position of the radiating element 20a for impedance matching of the antenna. The antenna 2 of this embodiment is supplied with power to the feeding point 20d and outputs a radio wave having a frequency of UHF band radio waves (for example, 953 MHz). As the substrate 20b, for example, an FR-4 substrate which is a glass epoxy substrate can be used. The ground plate 20 can be formed of, for example, a conductor, but the same function can be realized even if the back surface side of the substrate 20b is a full conductor. Moreover, the antenna element 20 can also be comprised with a sheet metal, without using the board | substrate 20b.

  As shown in FIGS. 1 and 2, the antenna 2 according to the present embodiment is on the floor surface below the display shelf 12 and in the longitudinal direction at the center position in the longitudinal direction of the mounting surface of the display shelf 12. The four antenna elements 20 described above are arranged in a row in a short direction perpendicular to the line. In such a state where the antenna 2 is arranged, if power is supplied simultaneously from the power supply device 4 to each of the radiating elements 20a as shown in FIG. 3, the combined action of the radio waves output from the radiating elements 20a The synthetic radio wave that spreads in the longitudinal direction of the mounting surface of the display shelf 12 is radiated from the antenna 2 toward the display shelf 12. A space in which the information stored in the RF tag 10 can be read and information can be written is shown as a readable area 30 in FIG.

  Here, based on FIGS. 6 to 8, as shown in FIG. 5, the radiation pattern of radio waves when radio waves are radiated from an array antenna configured by integrally arranging four antenna elements 20 in one row. Will be described. 6 to 8 are diagrams showing radiation patterns when power is simultaneously supplied to the antenna elements 20 of the array antenna shown in FIG. 5 to radiate radio waves. In this array antenna, antenna elements 20 are linearly arranged so that the distance between the centers thereof is 150 mm. When radio waves are radiated from this antenna, as shown in FIGS. 6 to 8, an ellipsoidal radiation pattern having a long directivity in the x-axis direction and a strong directivity in the z-axis direction is formed. In the present embodiment, this ellipsoidal range corresponds to the readable area 30. In the readable area 30 shown in FIG. 2 described above, the small radiation patterns formed on both sides of the large radiation pattern extending in the z-axis direction in FIGS. 6 and 7 are omitted.

  Thus, when radio waves are radiated from the antenna 2 which is an array antenna in which four antenna elements 20 are integrally arranged in a row, a readable area 30 having a longitudinal direction in a direction perpendicular to the longitudinal direction of the antenna 2 is formed. Is done. Accordingly, as shown in FIGS. 1 and 2, the antenna 2 is positioned in the longitudinal direction of the display shelf 12 at the center position in the longitudinal direction of the mounting surface of the display shelf 12 with respect to the display shelf 12. Are arranged on the floor surface so as to coincide with each other and radiate radio waves from the antenna 2, thereby forming a readable area 30 that substantially coincides with the arrangement space of the goods on the display shelf 12. Therefore, the radio wave radiated from the antenna 2 establishes wireless communication with the antenna 2 for any of the RF tags 10 attached to the products 14 placed on the display shelf 12, and the product management device 1 is surely connected. In addition, the RF tag 10 can be detected.

  Next, the power supply device 4 of the merchandise management device 1 is a device that distributes power to the antenna elements 20 constituting the antenna 2 at the same time as described above. Specifically, the power supply device 4 converts the power supplied from the communication device 6 to power having substantially the same phase and substantially the same amplitude for each of the antenna elements arranged in the same direction constituting the antenna 2. Distribute and supply. (However, for example, when there is an antenna element arranged in the opposite direction, power of opposite phase is supplied to the element.) Power that is out of phase or different in amplitude from each antenna element 20. This is because the synthesizing action of the radio waves radiated from the antenna elements 20 changes, and the ellipsoidal radiation pattern as shown in FIG. 6 is not formed. As the power supply device 4, for example, a power distributor can be used. In the present embodiment, the power supply device 4 as a power distributor is separated from the antenna 2, but is not limited to this, and may be integrally provided on the array antenna side.

  Next, the communication device 6 of the product management device 1 is a device called a reader / writer in so-called RFID technology, and in this embodiment, is a device having a function excluding the antenna function. Specifically, the communication device 6 controls processing such as reading information stored in the RF tag 10 and writing information to the RF tag 10.

  The communication device 6 includes a conversion unit that performs processing for converting information to be transmitted into an electrical signal, processing for converting a received signal into information that can be processed by the computer 8, a CPU that controls transmission and reception of information, and a CPU. A member (not shown) such as a memory for storing various programs to be executed is provided. In addition, the function as a control part which controls various processes, such as reading of the RF tag 10, is implement | achieved by executing various programs memorize | stored in memory with CPU.

  A specific process executed by the communication device 6 of the present embodiment first transmits a signal for obtaining ID information unique to an RF tag for identifying an RF tag 10 to be described later via the antenna 2. When the communication device 6 acquires a signal including ID information as a reflected radio wave from the RF tag 10 existing in the readable area 30, the signal indicating that the RF tag 10 is detected in the readable area 30 to the computer 8. (Hereinafter also referred to as a detection signal).

  On the other hand, when the RF tag 10 is moved out of the readable area 30 by taking out the product from the entrance / exit of the display shelf 12 (the wide side surface that appears on the front and back sides in FIG. 1), the product communicates with the RF tag 10. Wireless communication is no longer established with the device 6. Then, the communication device 6 stops transmitting the detection signal of the RF tag 10 to the computer 8. Then, the fact that the acquisition of the detection signal is stopped is recorded in the computer 8 so that it can be known when the RF tag 10 is taken out from the readable area 30.

  Note that the communication device 6 can also transmit information identifying the communication device 6 that acquired the ID information to the computer 8 in association with the acquired ID information of the RF tag. This is because the computer 8 stores the ID information and the information specifying the communication device 6 in association with each other so that the detected ID can be used even when a plurality of sets of the product management devices 1 are used. This is because it is possible to specify which communication device 6 has detected the information. The communication device 6 can also transmit information such as the time when the RF tag 10 is detected to the computer 8 in association with the ID information.

  A computer 8 connected to the communication device 6 is a terminal that collects and manages information acquired by the communication device 6. Specifically, the computer 8 is associated with ID information for identifying the RF tag 10 and information for identifying the product 14 such as a product management number (hereinafter also referred to as “product management number”), not shown. The database is stored. For example, when the RF tag 10 is attached to the product 14, the ID information of the RF tag in the database is associated with the product management number by storing the ID information in association with the product management number in the database. .

  When the computer 8 acquires the above-described detection signal from the communication device 6, the computer 8 refers to the database and specifies the corresponding product management number from the ID information of the RF tag included in the detection signal. Information indicating that the RF tag is present in the readable area 30 can be registered in association with the product management number.

  On the other hand, when the detection signal from the communication device 6 stops, the computer 8 can register information indicating that the RF tag 10 is no longer detected in the readable area 30 in association with the product management number.

  When information is registered in the database, the time when the presence of the RF tag is detected (or the time when the RF tag is detected) or the time when the RF tag is not detected (that is, the RF tag 10 is taken out from the display shelf 12). And the information of the communication device 6 that detected the removal are stored in association with the product management number. Thereby, the manager of the merchandise management system 1 refers to the database of the computer 8, and when the merchandise placed on which display shelf is picked up by the customer (or not picked up). Can know.

  Next, the RF tag 10 to be detected in the present embodiment will be described. As described above, the RF tag 10 receives a radio wave transmitted from the antenna 2 and returns a signal responding to the received radio wave to perform wireless communication with the antenna 2 and is called a so-called passive tag. It is a tag of type. The communication method is a radio wave method in which radio waves are transmitted and received between the antenna 2 and the RF tag 10. The RF tag 10 of the present embodiment is a tag capable of transmitting and receiving UHF band radio waves, and can communicate at a distance of about 3 m to 5 m from the antenna 2. When the antenna 2 is arranged on the floor below the display shelf 12, the distance between the antenna 2 and the RF tag 10 (product 14) of the display shelf 12 is normally considered to be within 3 m. The antenna 2 and the RF tag 10 can sufficiently communicate with each other. The RF tag 10 includes an IC chip in which ID information unique to each RF tag is stored. When receiving a radio wave requesting a reply of ID information from an antenna, a process of transmitting a radio wave including ID information It can be performed.

  According to the product management apparatus 1 having the above-described configuration, the antenna 2 that is an array antenna having a predetermined arrangement is disposed in the predetermined positional relationship with respect to the display shelf 12, so that the product arrangement space of the display shelf 12 can be obtained. The readable area 30 in which the RF tag 10 can be read can be formed in a space having an ellipsoidal shape that substantially coincides with. Therefore, in the product management device 1 of the present embodiment, when a product is taken out from the display shelf 12, the RF tag moves from the readable area 30 to the outside of the readable area, and the RF tag 10 is moved by the antenna 2 and the communication device 6. By not being detected, it can be detected that the RF tag 10 has gone out of the display shelf, that is, that the product has been taken out of the display shelf 12 by the customer.

  Next, a flow of processing for detecting that a product is taken out from the display shelf 12 by the product management apparatus 1 according to the present embodiment will be described.

  First, the communication device 6 outputs a signal for requesting the RF tag 10 to transmit ID information via the antenna 2. The antenna 2 transmits a radio wave of a predetermined frequency in the UHF band based on this signal, and forms a reading area 30 in a space that substantially coincides with the space in which the commodity on the display shelf 12 is arranged.

  In the state where the reading area 30 is formed, when the product 14 to which the RF tag 10 is attached is placed inside the display shelf 12, all the RF attached to the product by the antenna 2 and the communication device 6 are used. A tag is detected. Specifically, the RF tag 10 receives a radio wave radiated from the antenna 2, and the IC chip of the RF tag 10 performs a predetermined process using the radio wave, and is assigned to at least each RF tag 10. Reflects radio waves containing ID information. The antenna 2 receives the reflected radio wave from each RF tag 10, and the communication device 6 acquires the response signal of the RF tag 10 from the electrical signal by the radio wave.

  And the communication apparatus 6 will transmit the detection signal of the RF tag 10 mentioned above to the computer 8, if the response signal from an RF tag is acquired. The computer 8 searches the database based on the ID information of the RF tag 10 included in the acquired detection signal, and specifies the product management number corresponding to the ID information. Then, the computer 8 registers information indicating that the RF tag 10 is present on the display shelf 12 in association with the corresponding product management number.

  When any product 14 is taken out from the display shelf 12 from this state, the RF tag 10 attached to the product moves from the readable area 30 to the outside thereof. As a result, wireless communication established between the antenna 2 and the communication device 6 and the RF tag 10 is not performed, and the presence of the RF tag 10 is not detected.

  Then, transmission of the detection signal of the extracted RF tag 10 from the communication device 6 to the computer 8 is stopped. When the detection signal is no longer acquired, the computer 8 registers information indicating that the RF tag 10 is no longer detected in the readable area 30 in association with the corresponding product management number in the database.

  According to the product management apparatus 1 of the present embodiment described above, the readable area 30 in which the RF tag can be detected can be formed in a space that substantially matches the space in which the products on the display shelf 12 are arranged. For this reason, when a product with an RF tag placed on the display shelf 12 is taken out of the display shelf 12, the RF tag 10 is attached using the fact that the RF tag is not detected in the readable area 30. It is possible to reliably detect the removal of the merchandise.

  In addition, since the reading area 30 that substantially matches the space in which the products on the display shelf 12 are arranged can be formed, the entry / exit of only the RF tag existing in the space in which the products on the display shelf 12 are arranged is detected. It is also possible to obtain an effect that an RF tag attached to a product placed in a place other than the display shelf 12 is not erroneously detected.

  In the present embodiment, it has been described that the readable area 30 is formed in the entire space in which the products on the display shelf 12 are placed. However, the present invention is not limited to this. Of the display shelves 12, for example, the readable area 30 may be formed only in a part of the product arrangement space, such as forming the readable area 30 only in the product arrangement space corresponding to the bottom shelf. . In this case, for example, the shape of the reading area 30 may be changed by changing the output of the radio wave.

In the present embodiment, the antenna 2 is described as being disposed on the floor surface below the display shelf 12, but the present invention is not limited to this. For example, equipped respect display shelf 12 from the lower mounting surface of the lowermost goods display shelves 12, and on the uppermost shelf of shelf 12, or disposed above the shelf 12, the ceiling surface It can also be arranged.

  In the present embodiment, the merchandise management apparatus 1 has been described only for the case where the RF tag 10 is taken out from the display shelf 12. However, the present invention is not limited to this, and is outside the display shelf 12, that is, a readable area. Needless to say, it can be detected that the user has entered the readable area 30 from outside the area 30. By detecting that the product has entered the readable area 30, it is possible to detect that the product 14 once taken out from the display shelf 12 has been returned to the display shelf 12.

  In this case, the communication device 6 receives a response signal from the RF tag 10 that has entered the readable area 30 via the antenna 2, and transmits ID information included in the signal to the computer 8. Accordingly, the computer 8 can search the database based on the ID information and register information indicating that the RF tag 10 has entered the readable area 30 in the data of the corresponding product management number. The user of the product management apparatus 1 can know from the information registered in this database that the product has been returned to the display shelf 12.

  Therefore, according to the merchandise management apparatus 1 of the present embodiment, it is possible to acquire both information that the merchandise has been taken out from the display shelf 12 and that the merchandise has been placed on the display shelf 12 by detecting the RF tag 10. it can. Therefore, for example, based on the information of putting in and out of the product, for example, the proportion of a product that was taken out of the shelf and purchased was high, or the frequency of removal from the shelf was high but the purchase was not made. Various information about the product can be obtained.

  In the present embodiment, the communication device 6 transmits a detection signal to the computer 8 while the RF tag 10 is detected, and stops outputting the detection signal when the RF tag is no longer detected. However, the present invention is not limited to this. For example, a detection signal is transmitted to the computer 8 once when the RF tag 10 is first detected in the readable area 30, and then the RF tag 10 is moved and detected. If the RF tag 10 is no longer detected, a signal indicating that the RF tag 10 is no longer detected can be transmitted to the computer 8 together with the ID information of the RF tag. Also in this case, it is possible to know when the RF tag is taken out from the display shelf 12 in the database of the computer 8.

  In the present embodiment, each array antenna has been described as being configured by arranging antenna elements 20 having the same size. However, the present invention is not limited to this, and is radiated from the antenna elements 20 that are integrally arranged. The size of the antenna element can be changed within a range in which a readable area that is spread in a predetermined direction is formed by combining the radio waves.

(Second Embodiment)
Next, a second embodiment will be described based on FIG. FIG. 9 is a schematic view of the display shelf 12 in which the array antennas 2a and 2b of this embodiment are arranged in a predetermined arrangement and at a predetermined position, as viewed from above. As shown in FIG. 9, the merchandise management apparatus 1A of the present embodiment is different from the first embodiment in that the antenna 2 is composed of two array antennas 2a and 2b. Hereinafter, although the present embodiment will be described, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  As described above, the commodity management apparatus 1A of the present embodiment includes the antenna 2 configured by the two array antennas 2a and 2b, the power supply apparatus 4 that supplies power to the antenna 2, and the communication apparatus 6. Further, the point that the communication device 6 of the merchandise management device 1A is connected to the computer 8 that manages the acquired information and the like is the same as in the first embodiment.

  First, the antenna 2 includes two array antennas 2a and 2b in which antenna elements 20 are integrally arranged in 4 rows and 2 columns. As shown in FIG. 9, the two array antennas 2 a and 2 b are arranged so that the longitudinal direction of the array antennas 2 a and 2 b coincides with the short direction of the display shelf 12, and the products of the display shelf 12 Are arranged at equidistant positions from the center position in the longitudinal direction of the mounting surface.

  When radio waves are radiated from each of the array antennas 2a and 2b of the antenna 2, as shown in FIG. 9, readable areas 30a and 30b extending in a direction orthogonal to the longitudinal direction of the array antennas 2a and 2b are formed.

  However, since the antenna 2 of the present embodiment is an array antenna in which four antenna elements 20 arranged in a straight line are integrally arranged in two rows, the shape of the readable area 30 to be formed is the first implementation. Different from the case of form. First, regarding the spread of the readable area in the longitudinal direction of the array antenna, the array antennas 2a and 2b of the present embodiment are the same as the antenna 2 of the first embodiment. On the other hand, the spread of the readable area in the short direction of the array antenna is smaller than that of the antenna 2 in the first embodiment.

  Therefore, the antenna 2 of the present embodiment is more capable of detecting the RF tag 10 when the length of the display shelf 12 in the longitudinal direction is shorter than the display shelf targeted for detection in the first embodiment. Is suitable.

  However, if radio waves are simultaneously radiated from both of the array antennas 2a and 2b, the radio waves radiated from the array antennas 2a and 2b interfere with each other and are combined if the radio wave radiation ranges overlap. Then, the readable areas 30a and 30b as shown in FIG. 9 are not maintained, and a readable area that substantially matches the product arrangement space of the display shelf 12 cannot be formed.

  Therefore, the power supply device 4 and the communication device 6 of the present embodiment alternately supply power to the array antennas 2a and 2b so that radio waves are alternately emitted from the array antennas 2a and 2b. It is to be noted that the power of substantially the same phase and the same amplitude is supplied to each antenna element 20 constituting each of the array antennas 2a and 2b as in the case of the first embodiment. In the present embodiment, the power supply device 4 and the communication device 6 realize the function of the power supply unit in the claims.

  As for the power supply device 4, a function for distributing power to the antenna elements of the array antenna is provided as a distributor on the array antenna side, and the communication device 6 has a function for switching the power supply to each array antenna. It is good also as a separate apparatus structure.

  Since the communication device 6 and the computer 8 are the same as those in the first embodiment, description thereof is omitted.

  Next, processing for detecting removal of the RF tag 10 by the product management apparatus 1A of the present embodiment will be described.

  In the present embodiment, radio waves are radiated alternately from the two array antennas 2a and 2b. Therefore, in response to the timing at which radio waves are radiated from the antennas, response radio waves are radiated from the RF tags 10 existing in the readable areas 30a and 30b, and one of the array antennas 2a and 2b receives the radio waves. Will do. For example, response radio waves are radiated from the RF tag 10 in the readable area 30a in accordance with the timing at which radio waves are radiated from the array antenna 2a. In addition, a response radio wave is radiated from the RF tag 10 existing in an area where the readable areas 30a and 30b overlap each other with respect to the radio wave from any antenna.

  When either of the array antennas 2a and 2b receives the radio wave from the RF tag 10, the communication device 6 acquires the signal, and the communication device 6 sends the detection signal described in the first embodiment to the computer 8. Send. Based on the ID information included in the detection signal, the computer 8 registers information indicating that the RF tag 10 exists in the readable area in the database of the computer 8. The process of registering information in the database is the same as in the first embodiment.

  When the RF tag 10 is taken out from the readable area, the reflected wave from the RF tag 10 from which the antenna 2 is taken out is not received, and the communication device 6 sends the detection signal of the RF tag that is no longer detected to the computer 8. Stop sending.

  When the detection signal is no longer acquired, the computer 8 registers information indicating that the RF tag is no longer detected in the readable area 30 in association with the corresponding product management number in the database.

  According to the merchandise management apparatus 1A of the present embodiment as described above, even when the RF tag 10 is detected in the display shelf 12 that is shorter in the longitudinal direction than in the case of the first embodiment, the RF management is reliably performed. The tag 10 can be detected, and at the same time, there is an effect that there is little emission of radio waves to the outside of the shelf, and there is less chance of erroneously reading the RF tag outside the shelf. Note that by arranging a plurality of array antennas side by side, it is possible to deal with a long shelf in the longitudinal direction.

  In the present embodiment, it has been described that the RF tag 10 is used to detect that the product 14 with the RF tag 10 has been taken out from the display shelf 12, but in the case of the first embodiment. Similarly, it can be detected that the RF tag 10 enters the readable area 30a or 30b. Specific processing is as described in the first embodiment.

(Third embodiment)
Next, a third embodiment will be described based on FIG. FIG. 10 is a schematic view of the display shelf 12 in which the array antennas 2c, 2d, and 2e of the present embodiment are arranged in a predetermined arrangement and in a predetermined positional relationship, as viewed from above. As shown in FIG. 10, the merchandise management apparatus 1B of the present embodiment is different from the first and second embodiments in that the antenna 2 includes three array antennas 2c, 2d, and 2e. . Hereinafter, although this embodiment is described, about the same composition as a 1st embodiment and a 2nd embodiment, the same numerals are attached and explanation is omitted.

  The antenna 2 according to the present embodiment includes a total of three array antennas: an array antenna 2c arranged in 4 rows and 2 columns and an array antenna 2d and 2e arranged in 4 rows and 4 columns.

  The array antenna 2c is an antenna having the same arrangement as the array antennas 2a and 2b described in the second embodiment. Therefore, as in the case of the second embodiment, a reading area 30c extending in a direction orthogonal to the longitudinal direction of the array antenna 2c is formed from the array antenna 2c.

  On the other hand, the array antennas 2d and 2e are square array antennas arranged in 4 rows and 4 columns, and as shown in FIG. 10, substantially circular readable areas 30d and 30e are formed in a plan view.

  In the antenna 2 of this embodiment, the array antennas 2c to 2e are arranged in such a positional relationship that the readable areas 30d and 30e of the array antennas 2d and 2e are formed on both sides of the readable area 30c of the array antenna 2c. . That is, the square array antennas 2d and 2e are arranged on both sides of the array antenna 2c in the short direction.

  Accordingly, the readable area 30 (30c to 30e) formed by the radio wave radiated from the antenna 2 is formed in an elliptical shape having a longitudinal direction as a whole. Therefore, by arranging both of the longitudinal direction of the reading area 30 and the longitudinal direction of the display shelf 12 and arranging them, a readable area can be formed in a space that substantially coincides with the product placement space of the display shelf 12. . Therefore, it is possible to reliably detect that the RF tag 10 has been taken out from the product placement space of the display shelf 12 also by the product management apparatus 1B of the present embodiment.

  Furthermore, the entire readable area 30 formed by the antenna 2 of the present embodiment is formed with circular readable areas 30d and 30e in plan view at both ends thereof, so that the outer side from the product arrangement space of the display shelf 12 It doesn't stick out. Therefore, the RF tag 10 can be detected only for the product placed on the display shelf 12. For example, as shown in FIG. 10, even if another shelf or a hanger rack is arranged in an area adjacent to the display shelf 12 and there is a product with the RF tag 10, the RF tag that exists in that area is present. 10 is never detected.

  Here, based on FIGS. 12 to 14, the radiation pattern of the radio waves of the array antenna in which the antenna elements 20 are arranged in 4 rows and 4 columns as shown in FIG. 11 will be described. 12 shows a radiation pattern when radio waves are radiated from the array antenna shown in FIG. 11, FIG. 13 shows a radiation pattern on the yz plane of the radiation pattern shown in FIG. 12, and FIG. 14 shows a radiation pattern shown in FIG. It is a figure which shows the radiation pattern in xz plane of a pattern. As shown in FIGS. 12 to 14, in the case of a 4 × 4 array antenna, a radio wave having a radiation range having a circular cross section of the xy plane and a hemispherical tip is radiated from the antenna surface to the front thereof. . In this embodiment, this portion of the radiation pattern corresponds to the readable areas 30d and 30e.

  As in the case of the second embodiment, the power supply device 4 and the communication device 6 of the product management device 1B of the present embodiment are configured so that such three readable areas are formed independently. Electric power is alternately supplied to the array antennas 2c to 2e so that radio waves are alternately emitted from the respective antennas. As a result, as described in the second embodiment, the radio waves output from the array antennas are output without being synthesized. It is to be noted that, similarly to the second embodiment, the antenna elements 20 constituting each of the array antennas 2c to 2e are supplied with electric power having substantially the same phase and substantially the same amplitude.

  Other configurations and functions of the merchandise management apparatus 1B according to the present embodiment are the same as those in the first and second embodiments, and thus description thereof is omitted.

  According to the product management apparatus 1B of the present embodiment described above, the readable area can be formed in a space that is more consistent with the product placement space, and the RF tag can be read reliably. Furthermore, as an array antenna forming a readable area, an array antenna of 4 rows and 4 columns is arranged on both sides of the array antenna of 4 rows and 2 columns so that it does not protrude from both sides in the longitudinal direction of the product arrangement space. A readable area can be formed, and it is possible to reliably prevent the RF tag 2 existing in a place other than the display shelf 12 to be detected from being erroneously detected.

  In the present embodiment, the array antenna having a 4 × 4 array is arranged on both sides of the array antenna 2c forming the ellipsoidal readable area. However, the present invention is not limited to this. An array antenna in which antenna elements are arranged in a square shape can be used similarly. That is, if the antenna elements 20 are arranged in n rows and n columns (n is an integer of 2 or more), a circular readable area can be formed as viewed from the front of the antenna surface of the array antenna. In addition, the effect of not protruding from both sides of the product arrangement space can be obtained.

  Further, the array antenna arranged between the n-row and n-column array antennas does not have to be an array antenna of a 4-row / 2-column arrangement, and an ellipsoidal readable area having a longitudinal direction is formed. Any array antenna with an appropriate arrangement may be used. Specifically, if the array antenna has an array of n rows and m columns (m ≦ n and m is a natural number), an ellipsoidal readable area having a longitudinal direction in the direction orthogonal to the longitudinal direction of the array antenna is formed. Is done. Therefore, by using in combination with a square array antenna of n rows and n columns, a readable area having a shape along a rectangular product arrangement space can be efficiently formed with a small number of antenna elements. In this specification, “natural number” means a positive integer such as “1, 2, 3,...”, And “0” is not included.

  It is possible to form a readable area that substantially matches the product arrangement space by arranging a plurality of square array antennas of n rows and n columns, but the product placement surface is a rectangular shape having a longitudinal direction. Since the readable area formed by one array antenna is small, it is necessary to increase the number of array antennas as compared with a combination with an array antenna capable of forming an ellipsoidal readable area. In addition, a large number of antenna elements 20 constituting one array antenna are required. Therefore, it is preferable that the square array antenna is disposed on both ends in the longitudinal direction in the horizontal plane of the product layout space, and an array antenna capable of forming an elliptical readable area is disposed between the square array antennas.

  Even in this case, the square array antenna does not necessarily have to be disposed at positions corresponding to both sides of the mounting surface in the longitudinal direction, and may be disposed only on one end side. Even in such a case, it is possible to form a readable area that does not protrude from the product arrangement space.

(Fourth embodiment)
Next, a fourth embodiment will be described based on FIG. FIG. 15 is a schematic view of the display shelf 12 in which the array antennas 2f, 2g, and 2h constituting the antenna 2 of the present embodiment are arranged in a predetermined arrangement and in a predetermined positional relationship, as viewed from above. As shown in FIG. 15, the product management apparatus 1C of the present embodiment has the first to first differences in that the antenna 2 is composed of three array antennas 2f, 2g, and 2h, and the array method of the antenna elements of the array antenna is different. This is different from the third embodiment. Hereinafter, although this embodiment is described, about the same composition as the 1st-3rd embodiment, the same numerals are attached and explanation is omitted.

  The antenna 2 of the present embodiment is configured by three array antennas 2f to 2h, and in each array antenna, antenna elements 20 are arranged in 2 rows and 2 columns. And in the state arrange | positioned in the position corresponding to the floor surface under the display shelf 12, as shown in FIG. 15, rather than the distance between the antenna elements 20 in the longitudinal direction of the display shelf 12, it is a direction orthogonal to a longitudinal direction. They are arranged so that the distance between the antenna elements 20 in the (short direction of the display shelf 12) becomes long.

  As described above, when the distance between the antenna elements arranged in 2 rows and 2 columns is changed, a readable area having a longitudinal direction in the direction orthogonal to the direction in which the distance between the antenna elements is large is formed. Therefore, as shown in FIG. 15, the array antennas 2f to 2h are arranged so that the longitudinal directions of the readable areas 30f to 30h coincide with each other, thereby reading the ellipsoid spreading in the longitudinal direction of the entire antenna. A possible area 30 can be formed.

  Here, based on FIGS. 17-19, the radiation pattern of the radio wave of the array antenna in which the antenna elements 20 are arranged in 2 rows and 2 columns as shown in FIG. 16 will be described. 17 shows a radiation pattern when radio waves are radiated from the array antenna shown in FIG. 16, FIG. 18 shows a radiation pattern in the yz plane, and FIG. 19 shows a radiation pattern in the xz plane. . The array antenna whose radiation pattern is measured is arranged so that the distance between the centers of the antenna elements 20 in the y-axis direction shown in FIG. 16 is 250 mm, and the distance between the centers of the antenna elements 20 in the x-axis direction is 150 mm. It is arranged as follows. As the radiation pattern of the radio wave radiated from the array antenna, a radiation pattern having an elliptical cross section in the xy plane is obtained as shown in FIGS. In the present embodiment, this portion corresponds to the readable areas 30f to 30h formed by each array antenna.

  Since the other configuration of the product management device 1C of the present embodiment is the same as that of the first to third embodiments, the description thereof is omitted.

  According to the product management apparatus 1C of the present embodiment as described above, similarly to the other embodiments, a readable area that substantially coincides with the product placement space having the longitudinal direction on the product placement surface can be formed. The RF tag moving from the display shelf 12 can be reliably detected.

  In the present embodiment, the array antenna having an array of 2 rows and 2 columns has been described. However, the present invention is not limited to this, and the present invention is applied to other array antennas of n rows and n columns (n is an integer of 2 or more). be able to. In other words, if the array antenna has the same number of rows and columns, the above-mentioned ellipsoidal reading can be performed by setting the interval between the antenna elements in one direction larger than the interval in the other direction orthogonal to that direction. Possible areas can be formed.

  In each of the above-described embodiments, the display shelf on which the RF tag is detected is a shelf having a rectangular placement surface in which one side of the surface on which the product is placed is longer than the other side. However, the present invention is not limited to this, and it is needless to say that the RF tag can be detected in the same manner even in a product arrangement space having a substantially square mounting surface. In this case, as the antenna, for example, an array antenna having a square array of n rows and n columns as in the array antenna of 4 rows and 4 columns described in the third embodiment is suitable. An array antenna of n rows and n columns can form a readable area that substantially matches the product placement space formed by the square placement surface, and ensures that only the RF tag placed in the product placement space is provided. Can be detected. Further, a 2 × 4 array antenna having a small readable area in the longitudinal direction can also be used.

(Fifth embodiment)
Next, a fifth embodiment will be described.

  When power is evenly supplied to each antenna element constituting the array antenna, a radiation pattern (side lobe) with smaller radio waves appears in addition to a radiation pattern (main lobe) with large radio waves output from the array antenna. For example, if four antenna elements are arranged in a row and the same amount of power is supplied, side lobes appear on both sides of the main lobe as shown in FIG. 20, and the direction about 30 degrees above the horizontal plane (in FIG. 20, 60 A radio wave having a certain intensity is emitted at a position of degrees. In the example of FIG. 20, the gain of the main lobe is 11.5 dBi, and the gain of the side lobe is −1.4 dBi, which is 12.9 dB lower than the main lobe, but may be a magnitude that cannot be ignored depending on the application. The gain indicated by dBi represents an antenna gain with reference to an isotropic antenna (a virtual antenna that radiates radio waves equally in all directions).

  An object of the present invention is to provide a technique for reliably detecting that an article placed in the article placement space is taken out of the article placement space by reading an RF tag. There is a possibility that a malfunction occurs when it is detected that the product is taken out from the article placement space.

  FIG. 21 is a cross-sectional view of the display shelf as viewed from the short side, showing the state of radio waves radiated from the antenna placed under the shelf and the products 1 and 2 placed on the shelf. If product 1 is removed from the shelf and moved to position (a), it will be out of the radio wave radiated from the antenna, so the RF tag attached to the product will not be detected, and the product will be removed from the display shelf. It is possible to detect this. On the other hand, when the product 2 is taken out, the RF tag is detected by the side lobe because the product is in the side lobe when the product comes out of the display shelf due to the influence of the side lobe of the radio wave radiated from the antenna. Therefore, it is impossible to detect that the product has been taken out from the display shelf. After that, since the RF tag of the product 2 is not detected until the product 2 is pulled out to the position (a) where the influence of the side lobe is eliminated, the product 2 moves to the position (a), and the product is not moved from the display shelf for the first time. It is possible to detect the removal. Therefore, since the product 2 cannot be detected immediately after being taken out from the display shelf, it is difficult to accurately detect that the product has been taken out. Therefore, in the present embodiment, an apparatus that hardly generates side lobes is provided, and in the example of FIG. 21, a method of reliably detecting that the product 2 has been removed from the shelf is provided. Hereinafter, the commodity management apparatus according to the present embodiment will be described in detail by way of examples.

(First embodiment)
Hereinafter, based on FIG. 22 to FIG. 31, each device constituting the product management apparatus according to the first embodiment will be described. FIG. 22 is a schematic view of the display shelf in which the array antenna is arranged at a predetermined position as viewed from above. FIG. 23 is a block diagram for explaining a method of supplying power to the antenna elements constituting the array antenna.

  The antenna of the merchandise management apparatus is, for example, an array antenna in which three antenna elements 20 shown in FIG. 4 are integrally arranged in one row. Electric power is supplied to each antenna element constituting the array antenna through a power supply device connected to the communication device. Here, the power supply device supplies the central antenna element B with larger power than the end antenna elements A and C. For example, the power ratio supplied to each of the antenna elements A, B, and C is adjusted to be 1: 2: 1.

  FIGS. 25 to 27 show a power ratio of 1: 2: 1 to each of the antenna elements A, B, and C of the array antenna that is integrally arranged in three rows in one row shown in FIGS. It is a figure which shows the radiation pattern at the time of supplying radio waves and radiating | emitting an electromagnetic wave. In this array antenna, antenna elements are linearly arranged so that the distance between the centers thereof is 175 mm. When power is supplied from the array antenna at the above power ratio and radio waves are radiated, as shown in FIGS. 25 to 27, strong directivity is exhibited in the z-axis direction and strong radiation characteristics are also exhibited in the x-axis direction. A radiation pattern is formed.

  Here, as compared with the case where power is evenly supplied to each antenna element of the array antenna, the side lobe shown in FIG. 20 can be ignored as shown in the radiation pattern on the yz plane shown in FIG. It can be confirmed that the main lobe is almost only. In this way, the side lobe is reduced because the power ratio supplied to each of the antenna elements A, B, and C constituting the array antenna is set to 1: 2: 1 rather than equally. It is an effect.

  FIG. 28 is a cross-sectional view of the display shelf as viewed from the short side, and shows the state of radio waves radiated from the antenna placed under the shelf and the products 1 and 2 placed on the shelf. Each antenna element of the array antenna is arranged in a state where three antenna elements are arranged in a row in the short direction of the display shelf. Therefore, FIG. 28 shows the same radiation pattern as the radiation pattern in the yz plane of the array antenna shown in FIG. Here, the difference from FIG. 21 is that the antennas placed under the shelves are array antennas that are integrally arranged in a row, and the ratio of the antenna elements A, B, and C is 1: 2: 1. This is the point of supplying power. Since the radio wave radiated from the antenna is only the main lobe without the side lobe, the side lobe does not adversely affect the detection of the removal of the product placed on the display shelf. That is, if the product 1 placed on the display shelf is taken to the position (a) and the product 2 is taken to the position (b), the RF tag attached to the product is not detected and the product is taken out from the display shelf. It can be detected. In this way, since the side lobe radiated from the antenna is not affected, even when the product is placed on the lower shelf of the display shelf, the detection is detected when the product is removed from the shelf. There is a possible effect.

  In the above embodiment, the power ratio supplied to each of the antenna elements A, B, and C is 1: 2: 1. However, the present invention is not limited to this, and the power supplied to the central element B is If the electric power supplied to the elements A and C at both ends is somewhat larger than that, the same effect can be obtained although some side lobes are generated. Specifically, good characteristics can be obtained when the ratio is 1: 1.5: 1 to 1: 2.5: 1. 29 and 30 show the radiation characteristics in the yz plane when the power ratio is 1: 1.5: 1 and 1: 2.5: 1, respectively. For reference, Fig. 31 shows the radiation characteristics in the yz plane when the power ratio is 1: 3: 1. In this case, the radiation in the horizontal plane direction (direction of 90 degrees in the figure) is particularly large. The gain of the radio wave in the range from the horizontal plane (position of 90 degrees) to the direction 30 degrees above (the direction of 60 degrees in the figure) increases as a whole (the side lobe level in FIG. 31 is 8.7 dBi-14.4 dB = (It is -5.7dBi, which is much higher than the standard value of -10dBi), so it is impossible to ignore. Therefore, the power ratio should be suppressed to about 1: 2.5: 1.

  Moreover, although the case where it arranged linearly so that the distance between the centers of each antenna element may be set to 175 mm was described, it is not particularly limited to 175 mm, and the same effect can be obtained with other values.

(Second embodiment)
A second embodiment will be described with reference to FIGS. The antenna of the merchandise management apparatus according to the second embodiment is an array antenna in which four antenna elements 20 shown in FIG. 4 are integrally arranged in one row. FIG. 32 is a schematic view of a display shelf in which antennas are arranged at predetermined positions as viewed from above. FIG. 33 is a block diagram for explaining a method of supplying power to the antenna elements constituting the antenna. Each antenna element constituting the array antenna is supplied with power via the power supply apparatus connected to the communication apparatus. Supplied. Here, the power supply apparatus supplies two antenna elements B and C closer to the center of the array antenna to a larger power than the antenna elements A and D on the end side. For example, the power ratio supplied to each element of the antenna elements A, B, C, and D is adjusted to be 1: 2: 2: 1. 34 to 35 show the radiation characteristics of the radio waves of the array antenna when the antenna elements are linearly arranged so that the distance between the centers thereof is 150 mm and power is supplied to the array antenna at the above power ratio.

When radio waves are radiated from this antenna, as shown in FIG. 34, a radiation pattern having strong directivity in the z-axis direction and strong radiation characteristics in the x-axis direction is formed. FIG. 35 shows the radiation characteristics in the yz plane, but it can be confirmed that the side lobe is greatly reduced compared to the radiation pattern shown in FIG. 20 when power is evenly supplied to each element. .
In this way, in an array antenna consisting of 4 elements, radiation characteristics with fewer side lobes can be obtained by supplying larger power than the elements at both ends to the two elements closer to the center, and the product can be removed from the shelf. It is possible to reliably detect the removal.

  The power ratio supplied to each element is not limited to 1: 2: 2: 1. For example, the same effect can be obtained even at 1: 1.5: 1.5: 1 or 1: 2.5: 2.5: 1. can get. In addition, although the element interval has been described as 150 mm, it is not limited to this value.

(Third embodiment)
A third embodiment will be described with reference to FIGS. As shown in FIG. 36, the antenna of the merchandise management apparatus according to the third embodiment is a 3 × 2 array antenna in which three antenna elements 20 arranged in a straight line are integrally arranged in two columns. The element spacing is not particularly specified. For example, both the x and y spacings are set to 175 mm. Here, electric power larger than electric power supplied to other elements is supplied to the central elements B and E. For example, the power ratio supplied to each of the antenna elements A, B, C, D, E, and F is set to 1: 2: 1: 1: 2: 1 via a power supply device (not shown). (Ie, the antenna elements B and E are supplied with twice the power supplied to the remaining antenna elements A, C, D, and F). The radiation characteristics at this time are shown in FIGS.

  When radio waves are radiated from this antenna, a radiation pattern showing strong directivity in the z-axis direction is formed as shown in FIG. FIG. 38 shows the radiation characteristics in the yz plane, and FIG. 39 shows the radiation characteristics in the xz plane. The radiation characteristics in the yz plane are three array antennas arranged in one row as shown in FIG. The same characteristics as in, almost without side lobes can be obtained. The characteristics in the xz plane are such that the radiation in the horizontal (90 °) direction is weaker and the radiation in the upward direction is less than that in the case of the array antennas that are integrally arranged in three rows in one row shown in FIG. Become stronger. At the same time, radiation characteristics with few side lobes are obtained.

  FIG. 40 shows an example in which three sets of array antennas in which a total of six antenna elements, three in two rows, are arranged side by side are arranged below the display shelf. The readable area due to the radio waves radiated from each array antenna should be overlapped with the readable area of the adjacent array antenna, so that the insensitive area where the RF tag cannot be read on the display shelf is minimized. It is arranged with. Since the radio waves radiated from each array antenna have almost no side lobes, there is almost no malfunction when it is detected that a product placed on the display shelf has been taken out. Further, since the radiation directly above the array antenna is strong, there is little radiation in the side direction of the display shelf. For example, a product hung on a hanger is placed on the side of the display shelf (as shown in FIG. 10). Even if such a case is assumed, the rate of erroneously detecting the RF tag attached to the product can be kept low.

  In the present embodiment, the six-element array antenna in which three antenna elements 20 arranged in a straight line are integrally arranged in two rows has been described. However, the present invention is not limited to six elements. Can be applied. In the case of eight elements, as shown in FIG. 41, four antenna elements 20 arranged in a straight line are integrally arranged in two rows, but the four elements (B, C, F, G) can be supplied with larger power than the other four elements, so that unnecessary side lobes can be reduced, and malfunctions can be eliminated by detecting the removal of goods from the display shelf. For example, power is supplied to the eight antenna elements A to F at a ratio of 1: 2: 2: 1: 1: 2: 2: 1, respectively.

  Note that the power ratio supplied to each element is not limited to the above, and the same effect can be obtained even if the portion corresponding to “2” in the power ratio is, for example, about 1.5 to 2.5.

  In the example shown in FIG. 40, an example in which three sets of 6-element array antennas are arranged below the display shelf is shown. However, there is no need to configure only the same type of antennas. Of the antennas, only the central array antenna may be a three-element array antenna in which three antenna elements are integrally arranged in a row. Alternatively, only the central array antenna is a four-element array antenna in which four antenna elements are integrally arranged in one row, and array antennas arranged on both sides of the antenna elements are arranged in eight rows in which four antenna elements are integrally arranged. It may be an array antenna. Depending on the size of the display shelf, more than three sets of array antennas may be arranged, and the types of antennas to be arranged (how to arrange antenna elements, the number of array antennas, etc.) are not particularly limited.

  As a simpler configuration, as shown in FIG. 42, one set of array antennas can be arranged below the display shelf. The array antenna is not limited to six elements, and an array antenna having another number of elements may be used. In the example shown in FIG. 42, the longitudinal direction of the shelf coincides with the longitudinal direction of the array antenna.

  In the above-described example of the present embodiment, the array antenna having three or four array antennas in the longitudinal direction is shown, but the present invention is not limited to this. For example, even in the case of an array antenna having 5 or more array elements in the longitudinal direction, a power larger than the power supplied to the other outer antenna elements is supplied to the central antenna element in the longitudinal direction. By doing so, appearance of side lobes can be similarly suppressed. Specifically, array antennas are antenna elements arranged in n rows (n is a natural number) and m columns (m is a natural number satisfying m <n). Appearance of side lobes can be suppressed by supplying larger power than the antenna elements in the outer row. Here, the central row for increasing the power supply differs depending on the arrangement of the array antennas, but at least when n is an odd number, the central row (if n = 5, the third row, n = If it is 7, it is the fourth line, ie, {(n + 1) ÷ 2} line), and if n is an even number, the middle two lines (if n = 6, the third and fourth lines) , (N ÷ 2) line and (n ÷ 2 + 1) line), or any one of the two middle lines. In other words, depending on the arrangement of the antenna elements, if power supply is performed so that a power larger than the power supplied to the outer antenna element is supplied to the central antenna element so that side lobes do not appear. Good.

  According to the present embodiment, it is possible to provide a technique for reliably detecting that an article placed in the article placement space is taken out of the article placement space by reading an RF tag using radio waves. It is possible to reduce malfunctions due to side lobes radiated from the antenna when detecting removal from the article placement space.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the scope of claims, and is not restricted by the text of the specification. Further, all modifications, various improvements, alternatives and modifications belonging to the equivalent scope of the claims are all within the scope of the present invention.

  1, 1A, 1B, 1C Product management device, 2 antenna, 4 power supply device, 6 communication device, 8 computer, 10 RF tag, 12 display shelf, 14 product, 20 antenna element, 30 readable area

JP-A-9-325993

JP 2007-115152 A

JP 2007-37899 A

Claims (28)

An antenna including at least one array antenna configured by integrally arranging a plurality of antenna elements, and when the array antenna is disposed at a corresponding position, an article is disposed as the entire antenna. An antenna capable of emitting radio waves having an intensity distribution that enables wireless communication with an RF (Radio Frequency) tag arranged within a predetermined detection target range that substantially matches the article arrangement space;
A power supply unit for supplying power in units of the array antenna to each of a plurality of antenna elements that integrally form the array antenna;
A communication unit that transmits and receives signals to and from an RF tag attached to an article placed in the article placement space via the antenna;
An article management apparatus comprising: The article management apparatus according to claim 1, wherein
The antenna includes a plurality of the array antennas,
The article management apparatus, wherein the power supply unit supplies power to the plurality of array antennas at different timings. The article management apparatus according to claim 1 or 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The at least one array antenna is a single array antenna in which a plurality of antenna elements are arranged at a predetermined interval, and the size of the entire array antenna in the longitudinal direction is short in the horizontal plane of the article arrangement space. Article management device smaller than size. The article management apparatus according to claim 1 or 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The array antenna includes four antenna elements arranged in a line in a direction orthogonal to the longitudinal direction at a central position in the longitudinal direction. The article management apparatus according to claim 1 or 2,
The array antenna is an article management apparatus including 16 antenna elements arranged in 4 rows and 4 columns. The article management apparatus according to claim 1 or 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The array antenna includes four antenna elements arranged in two rows and two columns, and the distance between the antenna elements in the direction orthogonal to the longitudinal direction is larger than the distance between the antenna elements in the longitudinal direction. Management device. In the article management apparatus according to claim 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The antenna includes an antenna element including antenna elements arranged in n rows and n columns (n is an integer of 2 or more), and the array antenna arranged on at least one end side of both end portions in the longitudinal direction of the article arrangement space. Management device. The article management apparatus according to claim 7,
The antenna is
A first array antenna disposed on the one end side including the antenna elements arranged in 4 rows and 4 columns;
A second array antenna disposed on the other end side of the first array antenna, including the four antenna elements linearly arranged in a direction orthogonal to the longitudinal direction;
An article management apparatus comprising: In the article management apparatus according to claim 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The antenna is
Both ends in the longitudinal direction of the article arrangement space including the antenna elements arranged in n (n is a natural number) rows in a direction orthogonal to the longitudinal direction and m1 (m1 is an integer of 2 or more) columns in the longitudinal direction A first array antenna disposed on at least one end side of
Arranged on the other end side of the first array antenna including the antenna elements arranged in n rows in the direction orthogonal to the longitudinal direction and m2 (m2 is a natural number and m2 ≦ m1) columns in the longitudinal direction. A second array antenna,
An article management apparatus comprising: The article management apparatus according to claim 1, wherein
The article placement space is a space having a square cross section in a horizontal plane,
The antenna is an article management device including antenna elements arranged in n rows and n columns (n is an integer of 2 or more). An article placement shelf having an article placement space in which articles can be placed;
An antenna comprising at least one array antenna configured by integrally arranging a plurality of antennas, wherein the article is arranged as a whole when the array antenna is arranged at a corresponding position. An antenna capable of radiating radio waves having an intensity distribution that enables wireless communication with an RF tag arranged within a predetermined detection target range that substantially matches the arrangement space;
A power supply unit for supplying power in units of the array antenna to each of a plurality of antenna elements that integrally form the array antenna;
A communication unit that transmits and receives signals to and from an RF tag attached to an article placed in the article placement space via the antenna;
An article management system comprising: The article management system according to claim 11,
The antenna includes a plurality of the array antennas,
The article management system in which the power supply unit supplies power to the plurality of array antennas at different timings. The article management system according to claim 11 or 12,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The at least one array antenna is a single array antenna in which a plurality of antenna elements are arranged at a predetermined interval, and the size of the entire array antenna in the longitudinal direction is short in the horizontal plane of the article arrangement space. Goods management system smaller than size. The article management system according to claim 11,
The article placement space is a space having a square cross section in a horizontal plane,
The antenna is an article management system including antenna elements arranged in n rows and n columns (n is an integer of 2 or more). The article management apparatus according to any one of claims 1 to 14,
The antenna is an article management device that radiates radio waves having a frequency in the UHF band.
The article management apparatus according to claim 1 or 2,
The article arrangement space is a space having a longitudinal direction in any direction on a horizontal plane,
The said array antenna is an article | item management apparatus containing the three antenna elements arranged in a line in the direction orthogonal to the said longitudinal direction in the center position in the said longitudinal direction. The article management apparatus according to claim 16, wherein
The said power supply part is an article | item management apparatus which supplies electric power larger than the antenna element of an edge part to the antenna element of the center part which comprises the said array antenna. The article management apparatus according to claim 16, wherein
In the power supply unit, the power supplied to the central antenna element is 1.5 to 2.5 times the power supplied to the antenna elements at both ends of the three antenna elements arranged in a row. An article management apparatus that supplies electric power to be. The article management apparatus according to claim 16, wherein
The power supply unit supplies power to the three antenna elements arranged in a row so that the power supplied to the central antenna element is twice the power supplied to the antenna elements at both ends. Article management device. The article management apparatus according to claim 1 or 2,
The array antenna is an article management apparatus including six antenna elements arranged in three rows and two columns. The article management apparatus according to claim 20,
The power supply unit supplies power to each of the two antenna elements in the center for the total of six antenna elements arranged in 3 rows and 2 columns. An article management apparatus that supplies power so that the power is 1.5 to 2.5 times. The article management apparatus according to claim 20,
The power supply unit supplies power to each of the two antenna elements in the center for the total of six antenna elements arranged in 3 rows and 2 columns. An article management device that supplies electric power so as to be doubled. The article management apparatus according to claim 4.
The power supply unit is configured so that the power supplied to the two antenna elements at the center with respect to the four antenna elements arranged in a row is 1.5 to 2. An article management device that supplies electric power so as to be five times larger. The article management apparatus according to claim 4.
The power supply unit supplies power to the four antenna elements arranged in a row so that the power supplied to the two central elements is twice the power supplied to the elements at both ends. Supply article management device. The article management apparatus according to claim 1 or 2,
The array antenna is an article management apparatus including eight antenna elements arranged in four rows and two columns. The article management apparatus according to claim 25.
The power supply unit supplies power to each of the four antenna elements in the center, with respect to a total of eight antenna elements arranged in four rows and two columns. An article management apparatus that supplies power so that the power is 1.5 to 2.5 times. The article management apparatus according to claim 25.
The power supply unit supplies power to each of the four antenna elements in the center, with respect to a total of eight antenna elements arranged in four rows and two columns. An article management device that supplies electric power so as to be doubled. The article management apparatus according to claim 1 or 2,
The array antenna includes antenna elements arranged in n rows (n is a natural number) and m columns (m is a natural number satisfying m <n),
The said power supply part is an article | item management apparatus which supplies electric power larger than the electric power supplied to the antenna element of the row | line | column of the outer side to the antenna element of the center side row among n rows.