RF tag reading apparatus

Abstract

To provide an RF tag reading apparatus having an opening at the top of a storage part 100 and acquiring information from a passive RF tag inside the storage part 100 with the opening open, which prevents acquisition of information from an RF tag outside the storage part 100 due to diffraction of radio waves at the periphery of the opening.SOLUTION: A left side surface part 122, a rear surface part 123, and a right side surface part 124 include radio wave absorbing layers 142, 143, and 144, respectively, and are higher than a front surface part 121. The interior of a storage part 100 is divided into a first attenuation space between the front surface part 121 and a front surface storage limit part 151, in which no items are stored, and a storage space between the front surface storage limit part 151 and the rear surface part 123, in which items with RF tags attached can be stored. A bottom surface antenna 160 is installed on the upper surface of a bottom surface part, at a position to radiate radio waves with high intensity toward the storage space, and to radiate radio waves with lower intensity than the radio waves radiated toward the storage space toward the first attenuation space.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an RF tag reader that reads information from a passive RF (Radio Frequency) tag. [Background technology]

[0002] Patent Document 1 describes a stationary reader that reads information from an RF tag attached to an article. The reader includes an antenna and a shield. The antenna is housed inside the shield and emits radio waves for communicating with the RF tag. The shield surrounds the article. The shield has an opening facing upward that is wider than the article. The reader reads information from the RF tag with the shield open and facing upward.

[0003] FIG. 3 of Patent Document 1 shows an example of a reading device. In this example, the reading device is formed by four wall panels and a bottom panel, and has a rectangular housing that opens upward. Four wall panels are joined to each edge of the bottom panel, which are vertically erected relative to the bottom panel. Two horizontal panels are provided on the top and bottom of the housing. The upper horizontal panel is detachably supported by a shelf bracket. The lower horizontal panel is bonded to the inner wall surface of each wall panel. An antenna of a reader / writer is disposed on this lower horizontal panel.

[0004] In each wall panel, a radio wave reflecting sheet is attached to the inner wall surface that extends above the lower horizontal panel. The radio wave reflecting sheet functions as a radio wave reflecting layer that reflects radio waves on its surface. A radio wave absorbing sheet is attached to the entire inner surface of the radio wave reflecting sheet. The radio wave absorbing sheet functions as a radio wave absorbing layer that absorbs radio waves inside. Similarly, a radio wave reflecting sheet is attached to the upper surface of the lower horizontal panel, and a radio wave absorbing sheet is attached on top of the radio wave reflecting sheet.

[0005] In this way, in the reading device in Fig. 3 of Patent Document 1, a shield section with an upward opening is formed by radio wave reflection sheets and radio wave absorption sheets provided on each wall panel and the lower horizontal panel, and an antenna is installed on the bottom surface of the shield section. The shield section and the upper horizontal panel function as a storage section for storing a shopping basket.

[0006] In this reader, the radio waves emitted from the antenna are emitted only upwards outside the reader. Patent Document 1 states that in the reader shown in Fig. 3, the communication area with the RF tag is limited to the storage unit and the area above it, and there is no problem of erroneous reading of tag information on the RF tags of products around the reader.

[0007] Patent Document 2 describes a communication improvement device for improving the communication environment of a communication device equipped with a reader (reader antenna) and a transponder (IC tag). When each IC tag is present within the communication range of the reader antenna, it responds to a request signal from the reader antenna and transmits a response signal representing information about the item. In general, UHF band RFID tag systems are designed for long-distance communication, with a longer communication range and a wider communication range.

[0008] The article information handling equipment described in Patent Document 2 includes a transport device for transporting each article, a communication device having a reader antenna capable of wireless communication between a plurality of IC tags attached to each article and the IC tags, and a communication improvement device for improving the communication environment of the communication device. The reader antenna is provided at a fixed position, for example, above the transport device, facing the transport device, and supported by a support device. The reader antenna transmits and receives a request signal to and from the transport device.

[0009] The communication improvement device is supported by a support device and is provided between the IC tag placement area of ​​the transport device and the reader antenna. This communication improvement device combines frequency selective surface (FSS) technology with a radio wave absorber or radio wave shield. This is intended to operate the radio wave transmission area as a slot antenna and communicate with the IC tag using the radio waves re-radiated from the antenna part. For example, this can be achieved by making a cut in the conductor layer used in the radio wave absorber according to the frequency. However, even if the cut part is not strictly an antenna, it is possible to communicate by using the radio waves leaking from the gap. A radio wave absorber is an absorber that absorbs radio waves, but also has the function of shielding radio waves.

[0010] The communication improvement device is, for example, a radio wave absorber having a transparent area in the center that allows the radio waves to pass through. The transparent area is realized by forming a through hole, which serves as the transparent area. The reader antenna and each IC tag are arranged so as to communicate wirelessly through the transparent area. When the radio wave absorber is provided, the reader antenna can communicate only with each IC tag that is arranged in a position facing the transparent area. Patent Document 2 also states that if the transmission area is narrowed too much to increase the directivity of the radio waves from the reader antenna, diffracted waves will be generated after passing through the transmission area, resulting in cases where the directivity cannot be controlled. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent Application No. 2017-93449 [Patent Document 2] Patent Application No. 2007-240235 Summary of the Invention [Problem to be solved by the invention]

[0012] As described above, Patent Document 1 describes that in the reading device of Figure 3, the communication area with the RF tag is limited to the storage section and the area above it, and there is no problem of misreading the tag information of the RF tags of products located around the reading device.

[0013] However, in Japan's mobile phone system, the frequency band from 700 MHz to 900 MHz is called the golden band or platinum band. Radio waves in this frequency band are known to bend around obstacles due to diffraction. RFID systems are used, for example, in inventory management of products in factories (inspection and stocktaking), product inspection and stocktaking in intermediate logistics, and self-checkouts in stores. The radio waves used in these RFID systems are generally in the UHF band of 860 to 960 MHz. Radio waves in the UHF band of 860 to 960 MHz are also thought to be easily able to bend around obstacles due to diffraction.

[0014] Furthermore, as mentioned above, Patent Document 2 describes that when the transmission area is narrowed to increase the directivity of the radio waves from the reader antenna, if the area is narrowed too much, diffracted waves will be generated after passing through the transmission area, which may result in the directivity being uncontrollable.

[0015] For the above reasons, in reality, in the reading device of Figure 3 described in Patent Document 1, when the antenna and RF tag communicate using radio waves in the UHF band of, for example, 860 to 960 MHz, radio waves diffracted around the edge of the opening may cause RF tags outside the shield to operate, which may result in erroneous reading of tag information on the RF tags of products around the reading device.

[0016] In addition, the strength of the radio waves received by the RF tag weakens depending on the orientation of the RF tag relative to the antenna. Furthermore, it is known that when multiple RF tags are present inside a shield, the strength of the radio waves received by the RF tags weakens depending on their relative positions. For this reason, in the reader shown in Fig. 3 of Patent Document 1, if the radio waves emitted from the antenna are weakened to reduce the strength of the radio waves diffracted at the periphery of the opening, there is a risk that information from the RF tag inside the shield will not be read.

[0017] Therefore, when the frequency of the radio waves used in the reader described in Patent Document 1 is 860 to 960 MHz or lower, if the radio waves radiated from the antenna are strong, there is a high possibility that the tag information of the RF tag located around the reader will be misread. On the other hand, if the radio waves radiated from the antenna are weakened, the possibility of misreading the tag information of the RF tag located around the reader will decrease, but the possibility of failing to read information from the RF tag inside the shield will increase. For this reason, there is a limit to how much the radio waves radiated from the antenna can be weakened.

[0018] The object of the present invention is to provide an RF tag reading device that has an opening at the top of a storage section and acquires information from a passive RF tag located inside the storage section when the opening is open, and that can prevent erroneous acquisition of information from an RF tag located outside the storage section due to diffraction of radio waves at the periphery of the opening. [Means for solving the problem]

[0019] In order to achieve the above object, the RF tag reader of the present invention comprises: An RF tag reader that has a storage unit with an opening at the top through which an article having a passive RF tag attached can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom portion and a front portion on which an antenna for communicating with the RF tag is not installed; a first side portion having one end fixed to one end of the front portion, the first side portion not having an antenna for communicating with the RF tag; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion, one end and the other end of which are fixed to the other end of the back portion and the other end of the front portion, respectively, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being installed, and the upper end of the second side portion being higher than the upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves with a high intensity toward the accommodation space and radiates radio waves with an intensity lower than that of the radio waves radiated toward the accommodation space toward the first attenuation space; Equipped with.

[0020] Preferably, the RF tag reader of the present invention comprises: the first side portion includes an electromagnetic wave absorbing layer; The upper end of the first side surface portion is higher than the upper end of the front surface portion, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and because the upper end of the first side portion, the upper end of the back portion, and the upper end of the second side portion are higher than the upper end of the front portion and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the first side portion, the upper end of the back portion, and the upper end of the second side portion, the strength of the radio waves radiated from the bottom antenna and leaking outside the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0021] Preferably, the RF tag reader of the present invention comprises: a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; the bottom antenna is installed at a position where it radiates toward the second attenuation space a radio wave having a lower intensity than the radio wave radiated toward the accommodation space, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space and the second attenuation space, and because the upper end of the rear portion and the upper end of the second side portion are higher than the upper end of the front portion and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the bottom antenna and leaking outside the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0022] Preferably, the RF tag reader of the present invention comprises: The third storage limiting section is located above the bottom portion, and divides the inside of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not contained and through which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space.

[0023] In addition, the RF tag reader of the present invention comprises: An RF tag reader that has a storage unit with an opening at the top through which an article having a passive RF tag attached can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom surface portion including an electromagnetic wave absorbing layer and / or an electromagnetic wave reflecting layer; a front portion on which an antenna for communicating with the RF tag is not installed; a first side portion having one end fixed to one end of the front portion; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion, one end of which is fixed to the other end of the back portion, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being installed, and the upper end of the second side portion being higher than the upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves with a high intensity toward the accommodation space and radiates radio waves with an intensity lower than that of the radio waves radiated toward the accommodation space toward the first attenuation space; a side antenna disposed on an inner surface of the first side portion at a position that radiates a radio wave having a high intensity toward the accommodation space and radiates a radio wave having a lower intensity than the radio wave radiated toward the accommodation space toward the first attenuation space; Equipped with.

[0024] Preferably, the RF tag reader of the present invention comprises: the first side portion is composed of a lower portion, a middle portion and an upper portion, the lower portion standing upright from an edge of the bottom portion, the side antenna is installed in the lower portion, the lower portion and the middle portion include a radio wave absorbing layer and / or a radio wave reflecting layer, the upper portion stands upright from an upper end of the second accommodation limiting portion, the upper portion includes a radio wave absorbing layer, and the upper end of the upper portion is higher than the upper end of the front portion, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and because the top end of the upper part, the top end of the back part, and the top end of the second side part are higher than the top end of the front part and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the upper part, the top end of the back part, and the top end of the second side part, the strength of the radio waves radiated from the bottom antenna and leaking outside the storage section through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0025] Preferably, the RF tag reader of the present invention comprises: the first side portion has at least a lower portion, the lower portion stands upright from an edge of the bottom portion, the side antenna is installed on the lower portion, and there is a predetermined gap between an end portion of the first side portion on the side of the second accommodation limiting portion and the second accommodation limiting portion; the bottom antenna is installed at a position where it radiates toward the second attenuation space a radio wave having a lower intensity than the radio wave radiated toward the accommodation space, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the space between the end and the second accommodation limiting portion contained in the first attenuation space and the second attenuation space, and because the upper end of the rear portion and the upper end of the second side portion are higher than the upper end of the front portion and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the bottom antenna and leaking outside the accommodation portion through the opening is reduced, making it possible to obtain information from the RF tag inside the accommodation space.

[0026] Preferably, the RF tag reader of the present invention comprises: the other end of the second side surface portion is fixed to the other end of the front surface portion, Because the radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, and because the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0027] Preferably, the RF tag reader of the present invention comprises: The other end of the second side surface portion protrudes toward the front side by a predetermined length from the front surface portion, and the other end of the front surface portion is fixed between the other end and one end of the second side surface portion, Because the radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, the other end of the second side portion protrudes a predetermined distance toward the front side beyond the front portion, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0028] Preferably, the RF tag reader of the present invention comprises: The third storage limiting section is located above the bottom portion, and divides the inside of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not contained and through which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space.

[0029] In addition, the RF tag reader of the present invention comprises: An RF tag reader that has a storage unit with an opening at the top through which an article having a passive RF tag attached can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom surface portion including an electromagnetic wave absorbing layer and / or an electromagnetic wave reflecting layer; The front part and a first side portion having one end fixed to one end of the front portion; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion, one end of which is fixed to the other end of the back portion, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being installed, and the upper end of the second side portion being higher than the upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves with a high intensity toward the accommodation space and radiates radio waves with an intensity lower than that of the radio waves radiated toward the accommodation space toward the first attenuation space; a side antenna disposed on an inner surface of the first side portion at a position that radiates a radio wave having a high intensity toward the accommodation space and radiates a radio wave having a lower intensity than the radio wave radiated toward the accommodation space toward the first attenuation space; a front antenna disposed on an inner surface of the front portion; Equipped with.

[0030] Preferably, the RF tag reader of the present invention comprises: the first side portion is composed of a lower portion, a middle portion and an upper portion, the lower portion standing upright from an edge of the bottom portion, the side antenna is installed in the lower portion, the lower portion and the middle portion include a radio wave absorbing layer and / or a radio wave reflecting layer, the upper portion stands upright from an upper end of the second accommodation limiting portion, the upper portion includes a radio wave absorbing layer, and the upper end of the upper portion is higher than the upper end of the front portion, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and because the top end of the upper part, the top end of the back part, and the top end of the second side part are higher than the top end of the front part, and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the upper part, the top end of the back part, and the top end of the second side part, the strength of the radio waves radiated from the bottom antenna and leaking out of the storage space through the opening is reduced, making it possible to obtain information from an RF tag inside the storage space, The top end of the upper portion, the top end of the back portion, and the top end of the second side portion are higher than the upper edge of the front antenna, and the radio waves radiated from the front antenna are attenuated when they reach the top end of the upper portion, the top end of the back portion, and the top end of the second side portion. As a result, the strength of the radio waves radiated from the front antenna and leaking out of the storage section through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0031] Preferably, the RF tag reader of the present invention comprises: the first side portion has at least a lower portion, the lower portion stands upright from an edge of the bottom portion, the side antenna is installed on the lower portion, and there is a predetermined gap between an end portion of the first side portion on the side of the second accommodation limiting portion and the second accommodation limiting portion; the bottom antenna is installed at a position where it radiates toward the second attenuation space a radio wave having a lower intensity than the radio wave radiated toward the accommodation space, The radio waves radiated from the bottom antenna are attenuated while propagating through the space between the end and the second accommodation limiting portion, which are included in the first attenuation space and the second attenuation space, and the top end of the rear portion and the top end of the second side portion are higher than the top end of the front portion, and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the rear portion and the top end of the second side portion. This reduces the strength of the radio waves radiated from the bottom antenna and leaking outside the accommodation portion through the opening, making it possible to obtain information from an RF tag inside the accommodation space, The front antenna is installed at a position where it radiates radio waves with a high intensity toward the accommodation space and radiates radio waves with an intensity lower than that of the radio waves radiated toward the accommodation space toward the second attenuation space, Because the radio waves radiated from the front antenna are attenuated while propagating through the space between the end portion included in the second attenuation space and the second accommodation limiting portion, and because the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the front antenna and the radio waves radiated from the front antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the front antenna and leaking out of the accommodation portion through the opening is reduced, making it possible to obtain information from the RF tag inside the accommodation space.

[0032] Preferably, the RF tag reader of the present invention comprises: the other end of the second side surface portion is fixed to the other end of the front surface portion, Because the radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, and because the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0033] Preferably, the RF tag reader of the present invention comprises: The other end of the second side surface portion protrudes toward the front side by a predetermined length from the front surface portion, and the other end of the front surface portion is fixed between the other end and one end of the second side surface portion, Because the radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, the other end of the second side portion protrudes a predetermined distance toward the front side beyond the front portion, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion, the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening is reduced, making it possible to obtain information from the RF tag inside the storage space.

[0034] Preferably, the RF tag reader of the present invention comprises: The third storage limiting section is located above the bottom portion, and divides the inside of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not contained and through which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space. Effect of the Invention

[0035] According to the present invention, in an RF tag reading device that has an opening at the top of a storage section and acquires information from a passive RF tag located inside the storage section when the opening is open, it is possible to prevent erroneous acquisition of information from an RF tag located outside the storage section due to diffraction of radio waves at the periphery of the opening. [Brief description of the drawings]

[0036] [Figure 1] 1 is a perspective view of an example of an RF tag reader according to a first embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3]FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] 2 is a plan view of an example of a storage unit in the RF tag reader of FIG. 1. [Diagram 5] 4 is a diagram showing an example of radio waves radiated from a bottom antenna in the RF tag reader of FIG. 1 when the front portion includes a radio wave shielding layer. [Figure 6] 4 is a diagram showing an example of radio waves radiated from a bottom antenna in the RF tag reader of FIG. 1 when the front part does not include a radio wave shielding layer. [Figure 7] 2 is a diagram showing an RF tag reader that is a comparative example of the RF tag reader of FIG. 1, the rear surface of which includes a radio wave reflective layer. [Figure 8] 8 is a vertical cross-sectional view of an example of an RF tag reader according to a second embodiment of the present invention, which corresponds to a cross-sectional view taken along line AA in FIG. [Figure 9] FIG. 11 is a perspective view of an example of an RF tag reader according to a third embodiment of the present invention. [Figure 10] 10 is a cross-sectional view taken along line CC in FIG. 9. [Figure 11] 10 is a cross-sectional view taken along line DD in FIG. 9. [Figure 12] 10 is a plan view of an example of a storage unit in the RF tag reader of FIG. 9. [Figure 13] FIG. 13 is a perspective view of an example of an RF tag reader according to a fifth embodiment of the present invention. [Figure 14] 14 is a cross-sectional view taken along line EE in FIG. 13. [Figure 15] 14 is a cross-sectional view taken along the line FF in FIG. 13. [Figure 16] 14 is a plan view of an example of a storage section in the RF tag reader of FIG. 13. [Figure 17] 14 is a rear view of the RF tag reader of FIG. 13. FIG. [Figure 18] 14 is a diagram showing an example of radio waves radiated from a side antenna in the RF tag reader of FIG. 13. FIG. [Figure 19] 14 is a diagram showing an example of radio waves radiated from a side antenna and reaching a right side portion of the RF tag reader of FIG. 13, as viewed from the right side of the RF tag reader. [Figure 20] 20 is a vertical sectional view of an example of an RF tag reader according to a sixth embodiment of the present invention, which corresponds to a sectional view taken along line EE in FIG. [Figure 21] FIG. 13 is a perspective view of an example of an RF tag reader according to a seventh embodiment of the present invention. [Figure 22] 22 is a cross-sectional view taken along line GG in FIG. 21. [Figure 23] 22 is a cross-sectional view taken along line HH in FIG. 21. [Figure 24] 22 is a plan view of an example of a storage section in the RF tag reader of FIG. 21. FIG. [Diagram 25] 22 is a view of the RF tag reader in FIG. 21 as seen from the right side. [Figure 26] 22 is a diagram showing an example of radio waves radiated from a bottom antenna in the RF tag reader of FIG. 21. FIG. [Figure 27] 22 is a diagram showing an example of radio waves radiated from a side antenna in the RF tag reader of FIG. 21. FIG. [Figure 28] FIG. 13 is a perspective view of an example of an RF tag reader according to a ninth embodiment of the present invention. [Figure 29] 29 is a cross-sectional view taken along line II in FIG. 28. [Diagram 30] 29 is a cross-sectional view taken along line JJ in FIG. 28. [Diagram 31] 29 is a plan view of an example of a storage section in the RF tag reader of FIG. 28. [Diagram 32] FIG. 13 is a diagram for explaining an example of an effect provided by the RF tag reading device according to the ninth embodiment. [Diagram 33] 33 is a vertical sectional view of an example of an RF tag reader according to a tenth embodiment of the present invention, which corresponds to the cross-sectional view taken along line JJ in FIG. [Diagram 34] FIG. 23 is a perspective view of an example of an RF tag reader according to an eleventh embodiment of the present invention. [Diagram 35] 35 is a cross-sectional view taken along line KK in FIG. 34. [Diagram 36] 35 is a cross-sectional view taken along line LL in FIG. 34. [Figure 37]35 is a plan view of an example of a storage section in the RF tag reader of FIG. 34. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, an RF tag reader according to an embodiment of the present invention will be described in detail with reference to the drawings. In all the drawings explaining the embodiment, the same components are given the same reference numerals, and the repeated description will be omitted.

[0038] (First embodiment) Fig. 1 is a perspective view of an example of an RF tag reader 1 according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB in Fig. 1. Fig. 4 is a plan view of an example of a storage section 100 in the RF tag reader 1 of Fig. 1. The RF tag reader 1 has a storage unit 100 and a control unit 200. The storage unit 100 has an opening 110 at its top.

[0039] An opening 110 of the storage unit 100 of the RF tag reader 1 allows an article 300 with an RF tag 301 attached to be put in and taken out. The storage space inside the storage unit 100 is capable of storing the article 300. The storage space will be described later.

[0040] The opening 110 allows the insertion and removal of a shopping basket 400 containing the article 300 therein. The storage space inside the storage unit 100 is capable of storing a part or the whole of the shopping basket 400. For example, when the RF tag reader 1 is incorporated into a self-checkout register and used in a store, items 300 with RF tags 301 attached are displayed on shelves or tables in the store. A customer selects an item 300 that he or she likes and places it in a shopping basket 400. The customer then places a part or all of the shopping basket 400 into the storage space through the opening 110.

[0041] The article 300 is, for example, a book, an article of clothing, a food product, or the like. The article may be packed in a box. The article 300 is preferably an object that easily transmits radio waves. For example, the article 300 is preferably an object that does not contain metal or moisture. The RF tag 301 is used, for example, for centralized management of multiple items 300 throughout the entire supply chain including production, intermediate logistics, and sales. The RF tag 301 is used, for example, for inventory management (inspection and inventory) of products in factories, inspection and inventory of products in intermediate logistics, self-checkouts in stores, etc.

[0042] The RF tag 301 stores, for example, a unique tag ID (IDentifier) ​​that is determined so as to uniquely identify the article 300. When the article 300 to which the RF tag 301 is attached is stored inside the storage unit 100, the RF tag reader 1 reads information including the tag ID from the RF tag 301. The RF tag 301 is a well-known passive RF tag. The RF tag reader 1 communicates with the RF tag 301 using, for example, radio waves in the UHF band with a frequency of 860 to 960 MHz.

[0043] As shown in Figures 1 to 4, the storage section 100 has a bottom section 120, a front section 121, a left side section 122, a rear section 123, a right side section 124, a mounting plate 150, a front storage limit plate 151, a front guide section 153, and a bottom antenna 160. The bottom surface portion 120 constitutes the bottom of the housing portion 100. The bottom surface portion 120 is, for example, a rectangular flat plate. The bottom surface portion 120 includes a flat plate 130 and a radio wave shielding layer 140. The radio wave shielding layer 140 covers, for example, the upper surface of the flat plate 130. The bottom surface portion 120 does not necessarily need to include the radio wave shielding layer 140, but it is desirable for the bottom surface portion 120 to include the radio wave shielding layer 140 in order to suppress radio waves from penetrating into the inside of the housing portion 100 from the outside, for example. The radio wave shielding layer is a radio wave absorbing layer or a radio wave reflecting layer. The radio wave shielding layer may include both a radio wave absorbing layer and a radio wave reflecting layer. The radio wave absorbing layer absorbs radio waves. The radio wave absorbing layer is made of, for example, a radio wave absorbing sheet. The radio wave absorbing sheet is a sheet made of a material in which magnetic metal powder is mixed into a rubber material. The radio wave reflecting layer reflects radio waves. The radio wave reflecting layer is made of, for example, a metal. In the present invention, a structure in which a radio wave absorbing layer is layered on the inner surface (or upper surface) of the container 100 and a radio wave reflecting layer is layered on the outer surface (or lower surface) is also considered to be a type of radio wave absorbing layer.

[0044] The sides of the storage section 100 are made up of a front section 121, a left side section 122, a rear section 123, and a right side section . The front part 121 is, for example, rectangular. The front part 121 stands perpendicularly to the bottom part 120 from the edge of the front side of the bottom part 120. The front part 121 includes a flat plate 131 and a radio wave shielding layer 141. The radio wave shielding layer 141 covers, for example, the inner surface of the flat plate 131. The front part 121 does not necessarily have to include the radio wave shielding layer 141, but it is desirable for the front part 121 to include the radio wave shielding layer 141 in order to suppress radio waves from entering the inside of the housing part 100 from the outside. The upper end of the front part 121 is lower than the upper end of the left side part 122, the upper end of the back part 123, and the upper end of the right side part 124.

[0045] One end and the other end of the left side portion 122 are fixed to one end of the front portion 121 and one end of the back portion 123, respectively. The left side portion 122 is, for example, rectangular. The left side portion 122 includes a flat plate 132 and an electromagnetic wave absorbing layer 142. The electromagnetic wave absorbing layer 142 covers, for example, the inner surface of the flat plate 132. The left side portion 122 stands perpendicular to the left edge of the bottom portion 120. The upper end of the left side portion 122 is higher than the upper end of the front portion 121.

[0046] The rear portion 123 faces the front portion 121. One end and the other end of the rear portion 123 are fixed to the other end of the left side portion 122 and one end of the right side portion 124, respectively. The rear portion 123 is, for example, rectangular. The rear portion 123 includes a flat plate 133 and an electromagnetic wave absorbing layer 143. The electromagnetic wave absorbing layer 143 covers, for example, the inner surface of the flat plate 133. The rear portion 123 stands perpendicular to the bottom portion 120 from the edge on the rear side of the bottom portion 120. The upper end of the rear portion 123 is higher than the upper end of the front portion 121.

[0047] The right side portion 124 faces the left side portion 122. One end and the other end of the right side portion 124 are fixed to the other end of the rear portion 123 and the other end of the front portion 121, respectively. The right side portion 124 is, for example, rectangular. The right side portion 124 includes a flat plate 134 and an electromagnetic wave absorbing layer 144. The electromagnetic wave absorbing layer 144 covers, for example, the inner surface of the flat plate 134. The right side portion 124 stands perpendicular to the bottom portion 120 from the right edge of the bottom portion 120. The upper end of the right side portion 124 is higher than the upper end of the front portion 121.

[0048] The lower end of the front portion 121 , the lower end of the left side portion 122 , the lower end of the back portion 123 , and the lower end of the right side portion 124 are fixed to the respective edges of the bottom portion 120 . The storage section 100, which opens upward, is formed by the bottom section 120, the front section 121, the left side section 122, the back section 123, and the right side section 124. This opening is the opening 110 described above.

[0049] The radio wave shielding layer 141 included in the front portion 121 may cover the outer surface of the flat plate 131 instead of covering the inner surface of the flat plate 131, or may be sandwiched between two flat plates. The radio wave absorbing layer 142 included in the left side surface portion 122 may cover the outer surface of the flat plate 134 instead of covering the inner surface of the flat plate 132, or may be sandwiched between two flat plates. In this case, however, the flat plate on the inner surface side of the radio wave absorbing layer 142 must be made of a material that transmits radio waves. The rear surface portion 123 and the right side surface portion 124 are similar to the left side surface portion 122. Similarly, the radio wave shielding layer 140 included in the bottom surface portion 120 may cover the lower surface of the flat plate 130 instead of covering the upper surface of the flat plate 130, or may be sandwiched between two flat plates. The left side surface portion 122 is an example of a first side surface portion of the present invention, and the right side surface portion 124 is an example of a second side surface portion of the present invention.

[0050] The bottom antenna 160 is an antenna installed on the upper surface of the bottom part 120. The bottom antenna 160 radiates radio waves upward for communicating with the RF tag 301 and receives response radio waves transmitted from the RF tag 301. The bottom antenna 160 is, for example, a planar antenna or a sheet antenna. The bottom antenna 160 radiates, for example, circularly polarized radio waves, or radiates radio waves while switching between horizontal polarization and vertical polarization. The response radio wave is a radio wave carrying information and transmitted by the RF tag 301 when the RF tag 301 receives the radio wave from the bottom antenna 160. The same applies to the side antenna 161 and the front antenna 162 described later. It should be noted that no antennas for emitting radio waves for communicating with the RF tag 301 are provided on the front portion 121, the left side portion 122, the back portion 123, and the right side portion .

[0051] The mounting plate 150 is, for example, a rectangular flat plate. The mounting plate 150 is located above the bottom surface portion 120. The mounting plate 150 is fixed parallel to the bottom surface portion 120, at a predetermined distance from the bottom surface portion 120, for example, to the inner surfaces of the front surface portion 121, the left side surface portion 122, the rear surface portion 123, and the right side surface portion 124. The mounting plate 150 transmits radio waves. The front accommodation limiting plate 151 is, for example, a rectangular flat plate. The front accommodation limiting plate 151 is vertically erected from the upper surface of the mounting plate 150 between the front part 121 and the rear part 123, at a predetermined distance from the front part 121. The front accommodation limiting plate 151 transmits radio waves. The front guide part 153 is, for example, a flat plate. The lower end of the front guide part 153 is fixed to the upper end of the front accommodation limiting plate 151. The front guide part 153 extends diagonally upward, and its upper end is fixed to the upper end of the front part 121. One end and the other end of the front guide part 153 are fixed to the inner surface of the left side part 122 and the inner surface of the right side part 124, respectively. The front guide part 153 is transparent to radio waves. The front guide portion 153 may be parallel to the placement plate 150 instead of extending obliquely upward from the upper end of the front storage limiting plate 151. Also, the front guide portion 153 may not be provided.

[0052] The space above the placement plate 150 and surrounded by the front storage limit plate 151, the left side surface 122, the back surface 123, and the right side surface 124 is a storage space. The storage space is a space capable of storing part or all of the article 300 and / or the shopping basket 400. The article 300 and the shopping basket 400 are placed on the placement plate 150. The placement plate 150 divides the inside of the storage unit 100 into a space between the bottom surface 120 and the placement plate 150, and a space above the placement plate 150. Here, no article 300 or shopping basket 400 is stored in the space between the bottom surface 120 and the placement plate 150. This space is a space in which radio waves radiated from the bottom antenna 160 propagate while spreading. The space above the placement plate 150 is a storage space capable of storing the article 300 and the shopping basket 400. The front storage limiting plate 151 divides the inside of the storage section 100 into a space between the front portion 121 and the front storage limiting plate 151, and a space between the front storage limiting plate 151 and the rear portion 123. Here, no article 300 or shopping basket 400 is stored in the space between the front portion 121 and the front storage limiting plate 151. This space is a first attenuation space where radio waves radiated from the bottom antenna 160 propagate while being attenuated. The space between the front storage limiting plate 151 and the rear portion 123 is the storage space. The bottom antenna 160 is installed on the upper surface of the bottom portion 120 in a position to radiate radio waves of high intensity toward the storage space, and to radiate radio waves of lower intensity than the radio waves radiated toward the storage space toward the first attenuation space. The front storage limiting plate 151 is an example of a first storage limiting portion of the present invention, and the placement plate 150 is an example of a third storage limiting portion of the present invention.

[0053] The control unit 200 includes a transmission / reception unit 211, an acquisition unit 212, and an I / F (interface) 213. The transmitting / receiving unit 211 causes the bottom antenna 160 to radiate circularly polarized radio waves, or when linearly polarized waves are used, causes the bottom antenna 160 to radiate radio waves while switching between horizontally polarized waves and vertically polarized waves at high speed. Furthermore, when the bottom antenna 160 receives a response radio wave, the transmitting / receiving unit 211 obtains information including the tag ID from the response radio wave.

[0054] The RF tag 301 obtains the power necessary for operation by receiving radio waves transmitted from the bottom antenna 160. If the strength of the radio waves received by the RF tag 301 is less than a predetermined value, the RF tag 301 does not operate and does not transmit a response radio wave.

[0055] Fig. 5 shows an example of radio waves emitted from the bottom antenna 160 when the front part 121 includes the radio wave shielding layer 141. In Fig. 5, the RF tag 301 that receives radio waves within the range indicated by the diagonal dashed line slanting upward to the right operates and transmits a response radio wave. The upper end of the front part 121 in the RF tag reader 1 is low. However, the radio wave radiated from the bottom antenna 160 is attenuated while propagating through the first attenuation space between the front part 121 and the front storage limiting plate 151. The attenuated radio wave is diffracted at the upper end of the front part 121 (i.e., the periphery of the opening 110), passes over the upper end of the front part 121, and leaks from the opening 110 to the outside of the storage part 100. The transmitting / receiving part 211 causes the bottom antenna 160 to radiate toward the first attenuation space a radio wave of such intensity that the RF tag 301 outside the storage part 100 does not operate due to the radio wave diffracted at the upper end of the front part 121 and leaking from the opening 110 to the outside of the storage part 100. The diffracted wave diffracted at the upper end of the front part 121 has a low intensity, so that the RF tag 301 outside the storage part 100 does not operate.

[0056] Fig. 6 shows an example of radio waves emitted from the bottom antenna 160 when the front part 121 does not include the radio wave shielding layer 141. In Fig. 6, the RF tag 301 that receives radio waves within the range indicated by the diagonal dashed line slanting upward to the right operates and transmits a response radio wave. The radio waves emitted from the bottom antenna 160 are attenuated while propagating through the first attenuation space between the front part 121 and the front accommodation limiting plate 151. The transmitting / receiving part 211 causes the bottom antenna 160 to emit radio waves toward the first attenuation space, the intensity of which is reduced to such an extent that the RF tag 301 is not activated when the radio waves reach the front part 121. Therefore, the RF tag 301 outside the accommodation part 100 is not activated by the radio waves leaking from the front part 121 side to the outside of the accommodation part 100. In this case, the front part 121 does not need to include the radio wave shielding layer 141.

[0057] Since the strength of the radio waves radiated from the bottom antenna 160 to the storage space between the front storage limiting plate 151 and the rear part 123 is high, there is a low possibility that information will not be read from the RF tag 301 in the storage space. On the other hand, the strength of the radio waves radiated from the bottom antenna 160 to the first attenuation space between the front part 121 and the front storage limiting plate 151 is low. If the RF tag 301 is in the first attenuation space, there is a high possibility that information will not be read from the RF tag 301. However, the RF tag 301 is not placed in the first attenuation space.

[0058] Furthermore, the upper end of the left side surface portion 122, the upper end of the back surface portion 123, and the upper end of the right side surface portion 124 are higher than the upper end of the front surface portion 121. The radio waves radiated from the bottom antenna 160 are attenuated when they reach the upper end of the left side surface portion 122, the upper end of the back surface portion 123, and the upper end of the right side surface portion 124. The attenuated radio waves are diffracted at these upper ends (i.e., the periphery of the opening 110), and pass over these upper ends and leak from the opening 110 to the outside of the storage portion 100. The transmitting / receiving portion 211 causes the bottom antenna 160 to radiate radio waves of such an intensity that the RF tag 301 outside the storage portion 100 will not operate due to the radio waves diffracted at these upper ends and leaking from the opening 110 to the outside of the storage portion 100.

[0059] Furthermore, radio waves emitted from bottom antenna 160 may be reflected by the ceiling and reach RF tag 301 outside storage unit 100. However, the radio waves are attenuated before reaching the ceiling, and the reflected waves are further attenuated before reaching RF tag 301 outside storage unit 100. Transmitter / receiver 211 causes bottom antenna 160 to radiate radio waves of an intensity that will not cause RF tag 301 outside storage unit 100 to operate due to radio waves reflected by the ceiling. If the RF tag 301 does not operate, it will not transmit a response radio wave, and therefore the RF tag reader 1 will not acquire information from the RF tag 301 located outside the storage unit 100. Therefore, the RF tag reader 1 can acquire only information read from the RF tag 301 located inside the storage unit 100 when the bottom antenna 160 receives a response radio wave from the RF tag 301. That is, the RF tag reader 1 can acquire information from the RF tag 301 located inside the storage space by reducing the strength of the radio waves radiated from the bottom antenna 160 and leaking to the outside of the storage unit 100 through the opening 110.

[0060] The acquisition unit 212 acquires information about the RF tag 301 contained in the response radio wave received by the bottom antenna 160 . The I / F 213 transmits information about each RF tag 301 acquired by the acquisition unit 212 to an external device (such as an accounting device) and receives operating instructions for the RF tag reading device 1 from the external device.

[0061] (Comparative Example) FIG. 7 shows an RF tag reader 2 that is a comparative example of the RF tag reader 1 of FIG. 1, in which the back surface portion 123A includes a radio wave reflective layer 143A. The RF tag reader 2 in Fig. 7 differs from the RF tag reader 1 in Fig. 1 in that the rear surface 123A includes a radio wave reflecting layer 143A instead of a radio wave absorbing layer. In other respects, the configuration of the RF tag reader 2 is the same as the configuration of the RF tag reader 1. The sides of the storage section 101 in the RF tag reader 2 are made up of a front section 121, a left side section 122, a rear section 123A, and a right side section 124. The rear section 123A includes a flat plate 133 and a radio wave reflecting layer 143A. The radio wave reflecting layer 143A covers the inner surface of the flat plate 133, for example.

[0062] In the example of FIG. 7, RF tag 301 is held by a person or the like outside near housing portion 101 on the side of front portion 121, and RF tag 301 is located slightly higher than the upper end of front portion 121. The radio wave emitted from the bottom antenna 160 is reflected by the radio wave reflecting layer 143A. The strength of this reflected wave may be large. When this reflected wave passes the upper end of the front part 121 and leaks to the outside through the opening 110, the RF tag 301 located outside near the storage part 101 on the front part 121 side may be activated by this reflected wave. In this case, the response radio wave transmitted from this external RF tag 301 is also reflected by the radio wave reflecting layer 143A and reaches the bottom antenna 160. For this reason, the acquisition part 212 may acquire information of the RF tag 301 even though the RF tag 301 is located outside the storage part 101.

[0063] On the other hand, in the RF tag reading device 1 according to this embodiment, the radio waves radiated from the bottom antenna 160 are absorbed by the radio wave absorbing layer 143. Therefore, the radio waves do not reach the RF tag 301 located in the position shown in Fig. 7. Therefore, in the RF tag reading device 1 according to this embodiment, the acquiring unit 212 does not acquire information on the RF tag 301 located outside the storage unit 100.

[0064] Therefore, in the RF tag reader 1 according to this embodiment, it is essential that the rear surface portion 123 includes the radio wave absorbing layer 143. For the same reason as for the rear surface portion 123, it is essential that the left side surface portion 122 and the right side surface portion 123 also include radio wave absorbing layers. However, the front part 121 of the RF tag reader 1 may include a radio wave reflecting layer instead of a radio wave absorbing layer. Even if the radio wave emitted from the bottom antenna 160 is reflected by the front part 121, the radio wave travels toward the rear side. This is because the radio wave does not leak out from the opening 110 beyond the upper end of the front part 121 to the outside. However, if the front part 121 includes a radio wave reflecting layer, the radio waves (direct waves) radiated by the bottom antenna 160 may be reflected by the front part 121, and the direct waves and reflected waves may cause a multipath. If a multipath occurs, the direct waves radiated from the bottom antenna 160 may interfere with the reflected waves, and an area where the strength of the radio waves is low may be generated inside the storage part. If an RF tag 301 is present in this area, the RF tag 301 may not operate, and the acquisition part 212 may not be able to acquire information from the RF tag 301. For this reason, it is desirable for the front part 121 to include a radio wave absorbing layer.

[0065] Second embodiment 8 is a vertical cross-sectional view of an example of an RF tag reader 3 according to the second embodiment of the present invention, which corresponds to a cross-sectional view taken along line AA in FIG. The RF tag reader 3 includes a storage unit 100 and a control unit 201 . The configuration of the accommodation unit 100 of the RF tag reader 3 according to the second embodiment is the same as the configuration of the accommodation unit 100 of the RF tag reader 1 according to the first embodiment. The radio wave output of the bottom antenna 160 in the RF tag reader 3 according to the second embodiment is greater than that of the RF tag reader 1 according to the first embodiment. In the RF tag reader 3 according to the second embodiment, the RF tag 301 outside the storage section 100 may be operated by radio waves leaking to the outside from the opening 110.

[0066] The control unit 201 includes a transmission / reception unit 214, a determination unit 215, an acquisition unit 216, and an I / F (interface) 217. If the RF tag 301 has a function of transmitting a received signal strength indicator (RSSI), the transceiver 214 acquires information including the RSSI and the tag ID from the response radio wave when the bottom antenna 160 receives the response radio wave. In this case, the RSSI indicates the strength of the radio wave radiated from the bottom antenna 160 and received by the RF tag 301. Alternatively, when the bottom antenna 160 receives a response radio wave, the transmitting / receiving unit 214 obtains information including the strength of the response radio wave and the tag ID from the response radio wave.

[0067] If the RF tag 301 has a function of transmitting RSSI, the discrimination unit 215 discriminates, based on the RSSI acquired from the response radio wave received by the bottom antenna 160, whether the RF tag from which the RSSI was acquired is inside or outside the storage unit 100. For example, if the RSSI acquired from the response radio wave received by the bottom antenna 160 is equal to or greater than a predetermined first threshold, the discrimination unit 215 discriminates that the RF tag 301 is inside the storage unit 100 (i.e., inside the storage space).

[0068] Alternatively, the discrimination unit 215 discriminates, based on the strength of the response radio wave acquired from the response radio wave received by the bottom antenna 160, whether the RF tag 301 from which the strength of the response radio wave was acquired is inside or outside the storage unit 100. For example, when the strength of the response radio wave acquired from the response radio wave received by the bottom antenna 160 is equal to or greater than a predetermined second threshold, the discrimination unit 215 discriminates that the RF tag 301 is inside the storage unit 100 (i.e., inside the storage space).

[0069] The configuration of the storage unit 100 in the RF tag reader 3 according to the second embodiment is the same as the configuration of the storage unit 100 in the RF tag reader 1 according to the first embodiment. Therefore, hereinafter, the operation of the control unit 201 will be described with reference to Figures 5 and 6. However, unlike the above description of Figures 5 and 6, the determination unit 215 determines that the RF tag 301 is inside the storage unit 100 based on the RSSI acquired from the response radio wave transmitted by the RF tag 301 that received the radio wave within the range of the diagonal dashed lines slanting upward to the right in Figures 5 and 6, or based on the strength of the response radio wave. FIG. 5 shows an example in which the front part 121 includes the radio wave shielding layer 141. As shown in FIG. 5, the upper end of the front part 121 in the RF tag reader 3 is low. However, the radio wave radiated from the bottom antenna 160 is attenuated while propagating through the first attenuation space between the front part 121 and the front accommodation limiting plate 151. The attenuated radio wave is diffracted at the upper end of the front part 121 (i.e., the periphery of the opening 110), passes over the upper end of the front part 121, and leaks from the opening 110 to the outside of the accommodation part 100. The transmitting / receiving part 211 causes the bottom antenna 160 to radiate radio waves of an intensity that can determine that the RF tag 301 is outside the accommodation part 100 based on the response radio waves radiated from the RF tag 301 that has been activated by the radio waves diffracted at the upper end of the front part 121 and leaking from the opening 110 to the outside of the accommodation part 100, toward the first attenuation space. Since the diffracted waves diffracted at the upper end of the front part 121 have a small intensity, the RSSI included in the response radio wave transmitted from the RF tag 301 that received it is small. Also, the response radio wave transmitted from the RF tag 301 that received it is diffracted at the upper end of the front part 121 and reaches the bottom antenna 160, but the intensity of the response radio wave is also small. Therefore, the discrimination unit 215 can determine that the RF tag 301 is outside the storage unit 100 based on the RSSI acquired from the response radio wave received by the bottom antenna 160 or the intensity of the response radio wave.

[0070] Fig. 6 shows an example in which the front part 121 does not include the radio wave shielding layer 141. As shown in Fig. 6, the upper end of the front part 121 in the RF tag reader 3 is low. However, the radio waves emitted from the bottom antenna 160 are attenuated while propagating through the first attenuation space between the front part 121 and the front accommodation limiting plate 151. The transmitting / receiving part 211 causes the bottom antenna 160 to emit, toward the first attenuation space, radio waves of an intensity that can determine that the RF tag 301 is outside the accommodation part 100 based on the response radio waves emitted from the RF tag 301 that has been activated by the radio waves leaking from the front part 121 side to the outside of the accommodation part 100. Since the strength of the radio waves leaking from the front part 121 side to the outside of the storage part 100 is small, the RSSI included in the response radio waves transmitted from the RF tag 301 that received them is small. In addition, the strength of the response radio waves transmitted from the RF tag 301 that received them is also small. Therefore, the discrimination part 215 can determine that the RF tag 301 is outside the storage part 100 based on the RSSI acquired from the response radio waves received by the bottom antenna 160 or the strength of the response radio waves.

[0071] In addition, the upper end of the left side surface portion 122, the upper end of the back surface portion 123, and the upper end of the right side surface portion 124 are higher than the upper end of the front surface portion 121. The radio waves emitted from the bottom antenna 160 are attenuated when they reach the upper end of the left side surface portion 122, the upper end of the back surface portion 123, and the upper end of the right side surface portion 124. The attenuated radio waves are diffracted at these upper ends (i.e., the periphery of the opening 110), and pass over these upper ends and leak from the opening 110 to the outside of the storage portion 100. In the RF tag reading device 3, even if the RF tag 301 is operated by the radio waves diffracted at these upper ends and leaking from the opening 110 to the outside of the storage portion 100, the discrimination unit 215 can determine that the RF tag 301 is outside the storage portion 100 based on the RSSI included in the response radio waves transmitted from the RF tag 301 or the strength of the response radio waves.

[0072] Furthermore, there are cases where radio waves emitted from the bottom antenna 160 are reflected by the ceiling and reach the RF tag 301 outside the storage unit 100. However, the radio waves are attenuated before they reach the ceiling, and the reflected waves are further attenuated before they reach the RF tag 301 outside the storage unit 100. In the RF tag reading device 3, even if the RF tag 301 outside the storage unit 100 is activated by radio waves reflected by the ceiling, the discrimination unit 215 can discriminate that the RF tag 301 is outside the storage unit 100 based on the RSSI included in the response radio waves transmitted from the RF tag 301 or the strength of the response radio waves.

[0073] Therefore, when the bottom antenna 160 receives a response radio wave from the RF tag 301, the RF tag reader 3 can obtain only the information read from the RF tag 301 inside the storage section 100. In other words, the RF tag reader 3 can obtain information from the RF tag 301 inside the storage space by reducing the intensity of the radio wave radiated from the bottom antenna 160 and leaking to the outside of the storage section 100 through the opening 110.

[0074] For example, when the determination unit 215 determines that the RF tag 301 is inside the storage unit 100, the acquisition unit 216 acquires information read from the RF tag 301. This enables the RF tag reader 3 to acquire information about the RF tag 301 inside the storage space. The I / F 217 transmits the information acquired by the acquisition unit 216 to an external device (such as a checkout device) and receives operation instructions from the external device.

[0075] In addition, the acquisition unit 216 may also acquire information about the RF tag 301 that the discrimination unit 215 has determined to be outside the storage unit 100, and the I / F 217 may transmit the information about the RF tag 301 to an external device together with information indicating whether the RF tag 301 is inside or outside the storage unit 100.

[0076] (Third embodiment) FIG. 9 is a perspective view of an example of an RF tag reader 1A according to the third embodiment of the present invention. Fig. 10 is a cross-sectional view taken along line CC in Fig. 9. Fig. 11 is a cross-sectional view taken along line DD in Fig. 9. Fig. 12 is a plan view of an example of the containing section 100A in the RF tag reading device 1A in Fig. 9. The RF tag reader 1A includes a storage unit 100A and a control unit 200. The configuration of the control unit 200 of the RF tag reader 1A according to the third embodiment is the same as the configuration of the control unit 200 of the RF tag reader 1 according to the first embodiment. The transmitting / receiving unit 211 of the control unit 200 causes the bottom antenna 160 to radiate radio waves of such intensity that the RF tag 301 outside the housing unit 100A does not activate.

[0077] The storage section 100A has a bottom section 120, a front section 121, a left side section 122C, a rear section 123, a right side section 124, a mounting plate 150, a front storage limit plate 151, a side storage limit plate 152, a front guide section 153, a side guide section 154, and a bottom antenna 160. Unlike the left side surface portion 122 of the storage unit 100 according to the first embodiment, the upper end of the left side surface portion 122C in the storage unit 100A according to the third embodiment is at the same height as the upper end of the front surface portion 121. Also, the storage unit 100A differs from the storage unit 100 according to the first embodiment in that it has a side storage limiting plate 152 and a side guide portion 154. In other respects, the configuration of the storage unit 100A is the same as the configuration of the storage unit 100. The differences between the housing unit 100A and the housing unit 100 will be described below.

[0078] One end and the other end of the left side surface portion 122C are fixed to one end of the front surface portion 121 and one end of the rear surface portion 123, respectively. The left side surface portion 122C is a rectangular flat plate. The left side surface portion 122C stands perpendicular to the left edge of the bottom surface portion 120. The upper end of the left side surface portion 122C is at the same height as the upper end of the front surface portion 121, for example. The left side surface portion 122C includes a flat plate 132A and a radio wave shielding layer 142A. The radio wave shielding layer 142A covers, for example, the inner surface of the flat plate 132A. The left side surface portion 122C does not necessarily have to include the radio wave shielding layer 142A, but it is desirable for the left side surface portion 122C to include the radio wave shielding layer 142A in order to, for example, suppress radio waves from entering the inside of the housing portion 100A from the outside.

[0079] The side storage limiting plate 152 is, for example, a rectangular flat plate. The side storage limiting plate 152 is vertically erected from the upper surface of the mounting plate 150 between the left side surface portion 122C and the right side surface portion 124, at a predetermined distance from the left side surface portion 122C. The side storage limiting plate 152 transmits radio waves. The side guide portion 154 is, for example, a flat plate. The lower end of the side guide portion 154 is fixed to the upper end of the side accommodation limiting plate 152. The side guide portion 154 extends diagonally upward, and its upper end is fixed to the upper end of the left side portion 122C. One end and the other end of the side guide portion 154 are fixed to one end of the front guide portion 153 and the inner surface of the back portion 123, respectively. The other end of the front guide portion 153 is fixed to the inner surface of the right side portion 124. The side guide portion 154 is transparent to radio waves. The side guide portion 154 may be parallel to the placement plate 150 instead of extending obliquely upward from the upper end of the side storage limiting plate 152. Also, the side guide portion 154 may not be provided.

[0080] The space above the placement plate 150 and surrounded by the front storage limit plate 151, the side storage limit plate 152, the rear portion 123, and the right side portion 124 forms a storage space. The storage space is a space capable of storing part or all of the article 300 and / or the shopping basket 400. The article 300 and the shopping basket 400 are placed on the placement plate 150. The side storage limiting plate 152 divides the interior of the storage section 100A into a space between the left side surface portion 122C and the side storage limiting plate 152, and a space between the side storage limiting plate 152 and the right side surface portion 124. Here, no article 300 or shopping basket 400 is stored in the space between the side surface portion 122C and the side storage limiting plate 152. This space is a second attenuation space where radio waves radiated from the bottom antenna 160 propagate while being attenuated. The space between the side storage limiting plate 152 and the right side surface portion 124 is a storage space. The bottom antenna 160 is disposed at a position where it radiates radio waves with a high intensity toward the accommodation space, and radiates radio waves with an intensity lower than that radiated toward the accommodation space, toward the second attenuation space. The side storage limiting plate 152 is an example of a second storage limiting portion of the present invention.

[0081] The rear portion 123 faces the front portion 121. One end and the other end of the rear portion 123 are fixed to the other end of the left side portion 122C and one end of the right side portion 124, respectively.

[0082] Due to the difference between the structure of the storage unit 100A and the structure of the storage unit 100, there is a difference between the operation relating to the left side surface part 122C of the RF tag reader 1A according to the third embodiment and the operation relating to the left side surface part 122 of the RF tag reader 1 according to the first embodiment. The following describes the differences in the operation of the RF tag reader 1A from the operation of the RF tag reader 1. Note that in the RF tag reader 1A, the operation relating to the left side surface part 122C is similar to the operation relating to the front surface part 121 described with reference to Figs. 5 and 6 in the description of the RF tag reader 1 according to the first embodiment.

[0083] The left side surface portion 122C may or may not include the radio wave shielding layer 142A. First, a case where the left side surface portion 122C includes the radio wave shielding layer 142A will be described. The upper end of the left side surface portion 122C in the RF tag reading device 1A is low. However, the radio wave radiated from the bottom antenna 160 is attenuated while propagating through the second attenuation space between the left side surface portion 122C and the side accommodation limiting plate 152. The attenuated radio wave is diffracted at the upper end of the left side surface portion 122C (i.e., the periphery of the opening 110), passes over the upper end of the left side surface portion 122C, and leaks from the opening 110 to the outside of the accommodation portion 100A. The transmitting / receiving portion 211 causes the bottom antenna 160 to radiate radio waves of such intensity that the RF tag 301 outside the accommodation portion 100A will not operate due to the radio waves diffracted at the upper end of the left side surface portion 122C and leaking from the opening 110 to the outside of the accommodation portion 100A, toward the second attenuation space. The diffracted wave diffracted at the upper end of the left side surface portion 122C has a low intensity, so that the RF tag 301 outside the containing portion 100A does not operate.

[0084] Next, a case where the left side surface portion 122C does not include the radio wave shielding layer 142A will be described. The radio wave radiated from the bottom antenna 160 is attenuated while propagating through the second attenuation space between the left side surface portion 122C and the side accommodation limiting plate 152. The transmitting / receiving unit 211 causes the bottom antenna 160 to radiate radio waves toward the second attenuation space, the intensity of which is reduced to such an extent that the RF tag 301 is not activated when the radio waves reach the left side surface portion 122C. Therefore, the RF tag 301 outside the accommodation portion 100A is not activated by the radio waves leaking from the left side surface portion 122C side to the outside of the accommodation portion 100A.

[0085] Since the strength of the radio waves radiated from the bottom antenna 160 to the storage space between the side storage limiting plate 152 and the right side portion 124 is high, there is a low possibility that information will not be read from the RF tag 301 in the storage space. On the other hand, the strength of the radio waves radiated from the bottom antenna 160 to the second attenuation space between the left side portion 122C and the side storage limiting plate 152 is low. If the RF tag 301 were in the second attenuation space, there would be a high possibility that information would not be read from the RF tag 301. However, the RF tag 301 would not be placed in the second attenuation space.

[0086] In addition, the upper end of the rear portion 123 and the upper end of the right side portion 124 are higher than the upper end of the front portion 121. The radio waves radiated from the bottom antenna 160 are attenuated when they reach the upper end of the rear portion 123 and the upper end of the right side portion 124. The attenuated radio waves are diffracted at these upper ends (i.e., the periphery of the opening 110), and pass over these upper ends and leak from the opening 110 to the outside of the accommodating portion 100A. The transmitting / receiving portion 211 causes the bottom antenna 160 to radiate radio waves of such an intensity that the RF tag 301 outside the accommodating portion 100A will not operate due to the radio waves that pass over these upper ends and leak from the opening 110 to the outside of the accommodating portion 100A.

[0087] If the RF tag 301 does not operate, it will not transmit a response radio wave, and therefore the RF tag reader 1A will not acquire information from the RF tag 301 located outside the storage unit 100A. Therefore, when the bottom antenna 160 receives a response radio wave from the RF tag 301, the RF tag reader 1A can acquire only information read from the RF tag 301 located inside the storage unit 100A. That is, the RF tag reader 1A can acquire information from the RF tag 301 located inside the storage space by reducing the strength of the radio wave radiated from the bottom antenna 160 and leaking to the outside of the storage unit 100A through the opening 110.

[0088] In the RF tag reader 1A according to this embodiment, the left side surface portion 122C may include a radio wave reflecting layer instead of a radio wave absorbing layer. The radio wave emitted from the bottom antenna 160 is attenuated while propagating through the second attenuation space between the left side surface portion 122C and the side accommodation limiting portion 152. Therefore, when the radio wave reaches the left side surface portion 122C, its strength is reduced. If the distance between the left side surface portion 122C and the side accommodation limiting portion 152 is sufficiently large, even if the radio wave hits the left side surface portion 122C and is reflected, and leaks to the outside through the opening 110 beyond the upper end of the front surface portion 121, the RF tag 301 outside the accommodation portion 100A will not be activated by the leaked radio wave.

[0089] (Fourth embodiment) Although not shown, the RF tag reader according to the fourth embodiment includes a container 100A and a control unit 201. The configuration of the accommodating unit 100A is the same as that of the accommodating unit 100A of the RF tag reading device 1A according to the third embodiment, and the configuration of the control unit 201 is the same as that of the control unit 201 of the RF tag reading device 3 according to the second embodiment. In the RF tag reader 1A according to the third embodiment, the RF tag 301 outside the accommodating section 100A is not activated by radio waves radiated from the bottom antenna 160 and leaking from the opening 110 to the outside of the accommodating section 100A. In contrast, the radio wave output of the bottom antenna 160 in the RF tag reader according to the fourth embodiment is greater than that of the RF tag reader 1A according to the third embodiment. In the RF tag reader according to the fourth embodiment, the RF tag 301 outside the storage unit 100A may be activated by radio waves radiated from the bottom antenna 160 and leaking to the outside of the storage unit 100A through the opening 110. When the discrimination unit 215 receives a response radio wave from the RF tag 301, it discriminates whether the RF tag 301 is inside or outside the storage unit 100A based on the RSSI included in the response radio wave or the strength of the response radio wave.

[0090] Fifth embodiment Fig. 13 is a perspective view of an example of an RF tag reader 4 according to a fifth embodiment of the present invention. Fig. 14 is a cross-sectional view taken along line EE in Fig. 13. Fig. 15 is a cross-sectional view taken along line FF in Fig. 13. Fig. 16 is a plan view of an example of a storage section 102 in the RF tag reader 4 of Fig. 13. The RF tag reader 4 includes a storage unit 102 and a control unit 200A.

[0091] As shown in Figures 13 to 16, the storage section 102 has a bottom section 120, a front section 121, a left side section 122A, a rear section 123B, a right side section 124, a mounting plate 150, a front storage limiting plate 151, a side storage limiting plate 152, a front guide section 153, a bottom antenna 160, and a side antenna 161. The accommodating unit 102 according to the fifth embodiment differs from the accommodating unit 100 according to the first embodiment in that it has a side accommodation limiting plate 152 and a side antenna 161. Accordingly, the configurations of the left side surface portion 122A and the back surface portion 123B of the accommodating unit 102 differ from the configurations of the left side surface portion 122 and the back surface portion 123 of the accommodating unit 100. In other respects, the configuration of the accommodating unit 102 according to the fifth embodiment is the same as the configuration of the accommodating unit 100 according to the first embodiment. The differences between the accommodating unit 102 and the accommodating unit 100 will be described below.

[0092] One end and the other end of the left side surface portion 122A are fixed to one end of the front surface portion 121 and one end of the rear surface portion 123B, respectively. Left side surface portion 122A is composed of lower portion 1221, middle portion 1222, and upper portion 1223. Lower portion 1221 stands perpendicular to bottom surface portion 120 from the left edge of bottom surface portion 120. Middle portion 1222 extends from the upper end of lower portion 1221 in parallel to bottom surface portion 120 toward right side surface portion 124. Upper portion 1223 stands perpendicular to middle portion 1222 (and bottom surface portion 120) from the right edge of middle portion 1222. The lower portion 1221, the middle portion 1222, and the upper portion 1223 respectively include a rectangular flat plate 1321, a rectangular flat plate 1322, and a rectangular flat plate 1323. A radio wave shielding layer 142A covers the inner surfaces of the flat plates 1321 and 1322. A radio wave absorbing layer 142 covers the inner surface of the flat plate 1323. That is, the lower portion 1221 and the middle portion 1222 include the radio wave shielding layer 142A, and the upper portion 1223 includes the radio wave absorbing layer 142. The middle portion 1222 is at the same height as the upper end of the front portion 121. The upper end of the upper portion 1223 is at a constant height, and is at the same height as the upper end of the back portion 123B. Therefore, the upper end of the left side portion 122A (i.e., the upper end of the upper portion 1223) is higher than the upper end of the front portion 121.

[0093] The rear portion 123B faces the front portion 121. One end and the other end of the rear portion 123B are fixed to the other end of the left side portion 122A and one end of the right side portion 124, respectively. The rear portion 123B stands vertically from the rear edge of the bottom portion 120. As shown in FIG. 17, one end of the rear portion 123B is shaped to match the shape of the other end (i.e., the rear side) of the left side portion 122A. Therefore, the rear portion 123B is L-shaped. That is, the rear portion 123B is composed of a higher portion closer to the other end and a lower portion closer to the one end. The upper end of the lower portion closer to the one end is at the same height as the middle portion 1222 of the left side portion 122A. The upper end of the higher portion closer to the other end is at the same height as the upper end of the upper portion 1223 of the left side portion 122A. The upper end of the rear portion 123B is at a constant height and is higher than the upper end of the front portion 121. Here, the upper end of the rear portion 123B refers to the portion closer to the other end excluding the lower portion closer to the one end of the rear portion 123B. The back surface portion 123B includes an L-shaped flat plate 133A and an electromagnetic wave absorbing layer 143. The electromagnetic wave absorbing layer 143 covers, for example, the inner surface of the L-shaped flat plate 133A.

[0094] Right side surface portion 124 faces left side surface portion 122A. One end and the other end of right side surface portion 124 are fixed to the other end of rear surface portion 123B and the other end of front surface portion 121, respectively. The height of the upper end of right side surface portion 124 is the same as the height of the upper end of rear surface portion 123B. The upper end of right side surface portion 124 has a constant height and is higher than the upper end of front surface portion 121.

[0095] The radio wave absorbing layer 143 included in the back surface portion 123B may cover the outer surface of the L-shaped flat plate 133A instead of covering the inner surface of the L-shaped flat plate 133A, or may be sandwiched between two L-shaped flat plates. In this case, however, the L-shaped flat plate on the inner surface side of the radio wave absorbing layer 143 must be made of a material that transmits radio waves. The left side surface portion 122A is an example of a first side surface portion of the present invention, and the right side surface portion 124 is an example of a second side surface portion of the present invention.

[0096] The side antenna 161 is an antenna installed on the inner surface of the lower portion 1221 of the left side surface portion 122A (i.e., the inner surface of the left side surface portion 122A). The side antenna 161 radiates radio waves for communicating with the RF tag 301 toward the right side surface portion 124, and receives response radio waves transmitted from the RF tag 301. The side antenna 161 is, for example, a planar antenna or a sheet antenna. The side antenna 161 radiates, for example, circularly polarized radio waves, or radiates radio waves while switching between horizontally polarized waves and vertically polarized waves. The upper end of rear portion 123B and the upper end of right side portion 124 are higher than the upper edge of side antenna 161. Here, the upper edge of side antenna 161 refers to the highest position of the portion of side antenna 161 that radiates radio waves. In order to prevent radio waves radiated from the side antenna 161 from leaking from the bottom portion 120 to the outside of the housing portion 102 , it is preferable that the bottom portion 120 includes a radio wave shielding layer 140 . It should be noted that no antenna for emitting radio waves for communicating with the RF tag 301 is provided on the front portion 121, the back portion 123B, or the right side portion .

[0097] The side storage limiting plate 152 is, for example, a rectangular flat plate. The side storage limiting plate 152 is vertically erected from the upper surface of the mounting plate 150 between the side antenna 161 and the bottom antenna 160, at a predetermined distance from the lower portion 1221 of the left side surface portion 122A. The upper end of the side storage limiting plate 152 is fixed, for example, to the lower end of the upper portion 1223 in the left side surface portion 122A. The upper portion 1223 is vertically erected from the upper end of the side storage limiting plate 152. The height of the side storage limiting plate 152 is the same as the distance between the upper surface of the mounting plate 150 and the lower surface of the middle portion 1222 in the left side surface portion 122A. One end and the other end of the side storage limiting plate 152 are fixed, for example, to the front portion 121 and the rear portion 123B, respectively, and the width of the side storage limiting plate 152 is the same as the distance between the front portion 121 and the rear portion 123B. The side accommodation limiting plate 152 allows radio waves to pass through.

[0098] The side storage limit plate 152 divides the inside of the storage section 102 into a space between the left side portion 122A and the side storage limit plate 152, and a space between the side storage limit plate 152 and the right side portion 124. Here, no article 300 or shopping basket 400 is stored in the space between the left side portion 122A and the side storage limit plate 152. This space is a second attenuation space where radio waves radiated from the side antenna 161 propagate while spreading. The space between the side storage limit plate 152 and the right side portion 124 is a storage space. The side antenna 161 is installed on the inner surface of the lower part 1221 of the left side part 122A in a position so as to radiate radio waves of high intensity toward the storage space, and to radiate radio waves of lower intensity than the radio waves radiated toward the storage space toward a first attenuation space between the front part 121 and the front storage limit plate 151. The side storage limiting plate 152 is an example of a second storage limiting portion of the present invention.

[0099] The radio waves radiated from bottom antenna 160 propagate while being attenuated through the second attenuation space between left side portion 122A and side accommodation limiting plate 152. However, these radio waves are reflected or absorbed by the lower surface of middle portion 1222 and the inner surface of lower portion 1221 in left side portion 122A. In RF tag reader 4, the radio waves radiated from bottom antenna 160 and reflected or absorbed by lower portion 1221 and middle portion 1222 do not leak out of accommodation portion 102.

[0100] A control unit 200A of an RF tag reader 4 according to the fifth embodiment differs from the control unit 200 of the RF tag reader 1 according to the first embodiment in that the control unit 200A controls the side antenna 161. In other respects, the operation of the control unit 200A is the same as the operation of the control unit 200. The control unit 200A includes a transmission / reception unit 211A, an acquisition unit 212A, and an I / F (interface) 213A. The transmitting / receiving unit 211A controls the side antenna 161 in addition to the bottom antenna 160. The transmitting / receiving unit 211A causes the bottom antenna 160 and the side antenna 161 to radiate, for example, circularly polarized radio waves, or when linearly polarized waves are used, causes the bottom antenna 160 and the side antenna 161 to radiate radio waves while switching between horizontally polarized waves and vertically polarized waves at high speed. Furthermore, when the bottom antenna 160 and the side antenna 161 receive a response radio wave, the transmitting / receiving unit 211A obtains information including the tag ID from the response radio wave. The transmission / reception unit 211A may cause the bottom antenna 160 and the side antenna 161 to radiate radio waves at different times, or may cause the bottom antenna 160 and the side antenna 161 to radiate radio waves simultaneously if mutual interference between the radio waves radiated from the bottom antenna 160 and the side antenna 161 can be ignored.

[0101] The RF tag 301 obtains the power necessary to operate by receiving radio waves transmitted from one or more of the bottom antenna 160 and the side antenna 161. If the strength of the radio waves received by the RF tag 301 is less than a predetermined value, the RF tag 301 does not operate and does not transmit a response radio wave. As in the RF tag reader 1 according to the first embodiment, in the RF tag reader 4, the radio waves radiated from the bottom antenna 160 are attenuated while propagating through the space between the front part 121 and the front storage limiting part 151. In the RF tag reader 4, the transmitter / receiver 211A causes the bottom antenna 160 to radiate radio waves of such an intensity that the RF tag 301 outside the storage part 102 will not function due to radio waves leaking from the upper end of the front part 121 to the outside of the storage part 102. Also, in the RF tag reader 4, the top end of the left side surface portion 122A (the top end of the upper portion 1223), the top end of the back surface portion 123B, and the top end of the right side surface portion 124 are higher than the top end of the front surface portion 121. The radio waves radiated from the bottom surface antenna 160 are attenuated by the time they reach the top end of the upper portion 1223, the top end of the back surface portion 123B, and the top end of the right side surface portion 124. The transmitting / receiving unit 211A causes the bottom surface antenna 160 to radiate radio waves of such an intensity that the RF tag 301 outside the storage unit 102 will not function due to the radio waves diffracted at these top ends and leaking outside the storage unit 102.

[0102] Fig. 18 shows an example of radio waves emitted from the side antenna 161 in the RF tag reader 4 of Fig. 13. The RF tag 301 that receives radio waves within the range indicated by the diagonal dashed line rising upward to the right operates and transmits a response radio wave. The radio waves radiated from side antenna 161 pass over the upper end of rear portion 123B and the upper end of right side portion 124 (i.e., the periphery of opening 110) and leak from opening 110 to the outside of storage portion 102. However, the upper end of rear portion 123B and the upper end of right side portion 124 are higher than the upper edge of side antenna 161. The radio waves radiated from side antenna 161 are attenuated by the time they reach the upper end of rear portion 123B and the upper end of right side portion 124. Transmitter / receiver 211A causes side antenna 161 to radiate radio waves of such intensity that RF tag 301 outside storage portion 102 will not operate due to the radio waves that pass over these upper ends and leak from opening 110 to the outside of storage portion 102.

[0103] Moreover, the radio waves radiated from side antenna 161 are diffracted upward at the right end of middle portion 1222 of left side surface portion 122A, and are further diffracted at the upper end of upper portion 1223 and propagated to the left of storage unit 102. However, the strength of the radio waves propagating to the left of storage unit 102 is lower than the strength of the radio waves radiated from side antenna 161. In RF tag reading device 4, the strength of the radio waves radiated from side antenna 161 and propagating to the left of storage unit 102 is at a level that does not activate RF tag 301 outside storage unit 102.

[0104] Fig. 19 shows an example of radio waves radiated from the side antenna 161 and reaching the right side part 124 in the RF tag reader 4 of Fig. 13, as viewed from the right side of the RF tag reader 4. The RF tag 301 that receives radio waves within the range of the diagonal dashed line sloping upward to the right operates and transmits a response radio wave. The radio wave radiated from the side antenna 161 propagates through the first attenuation space between the front part 121 and the front accommodation limiting part 151. This radio wave is diffracted at the upper end of the front part 121 (i.e., the periphery of the opening 110), and passes over the upper end of the front part 121 and leaks from the opening 110 to the outside of the accommodation part 102. This radio wave also leaks from the other end of the right side part 124 (i.e., from the opening 110) to the outside of the accommodation part 102. However, the radio wave radiated from the side antenna 161 is attenuated while propagating through the first attenuation space between the front part 121 and the front accommodation limiting part 151. The transmitting / receiving part 211A causes the side antenna 161 to radiate radio waves of such intensity that the RF tag 301 outside the accommodation part 102 does not operate due to the radio waves leaking from the upper end of the front part 121 and the other end of the right side part 124 to the outside of the accommodation part 102.

[0105] If the RF tag 301 does not operate, it will not transmit any response radio waves, and therefore the RF tag reader 4 will not acquire information from the RF tag 301 located outside the storage unit 102. Therefore, when the side antenna 161 receives a response radio wave from the RF tag 301, the RF tag reader 4 can acquire only information read from the RF tag 301 located inside the storage unit 102.

[0106] The acquisition unit 212A identifies each RF tag 301 based on the tag ID included in the information of the RF tag 301 acquired from the response radio waves received by the bottom antenna 160 and the side antenna 161, respectively, and acquires the information for each RF tag 301. The I / F 213A transmits information about each RF tag 301 identified by the acquisition unit 212A to an external device (such as an accounting device) and receives operating instructions for the RF tag reader 4 from an external device.

[0107] Right side surface portion 124 includes radio wave absorbing layer 144, but if right side surface portion 124 included a radio wave reflecting layer, strong radio waves radiated from side antenna 161 toward the housing space would be reflected by right side surface portion 124, and the reflected waves would risk leaking outside housing portion 102 over the upper end of front surface portion 121. Since the strength of these reflected waves may be large, it is essential that right side surface portion 124 includes radio wave absorbing layer 144.

[0108] Sixth embodiment 20 is a vertical cross-sectional view of an example of an RF tag reader 5 according to the sixth embodiment of the present invention. Fig. 20 corresponds to a cross-sectional view taken along line EE in Fig. 13 . The RF tag reader 5 includes a storage unit 102 and a control unit 201A. The configuration of the accommodating section 102 of the RF tag reader 5 according to the sixth embodiment is the same as the configuration of the accommodating section 102 of the RF tag reader 4 according to the fifth embodiment. The radio wave output of the bottom antenna 160 and the side antenna 161 in the RF tag reader 5 according to the sixth embodiment is greater than those in the RF tag reader 4 according to the fifth embodiment. In the RF tag reader 5 according to the sixth embodiment, the RF tag 301 outside the storage section 102 may be activated by radio waves leaking to the outside from the opening 110.

[0109] A control unit 201A of an RF tag reader 5 according to the sixth embodiment differs from the control unit 201 of the RF tag reader 3 according to the second embodiment in that the control unit 201A controls the side antenna 161. Regarding the control of the bottom antenna 160, the operation of the control unit 201A is the same as that of the control unit 201. The control unit 201A has a transmission / reception unit 214A, a determination unit 215A, an acquisition unit 216A, and an I / F (interface) 217A. The transmitting / receiving unit 214A controls the side antenna 161 in addition to the bottom antenna 160. The transmitting / receiving unit 214A causes the bottom antenna 160 and the side antenna 161 to radiate, for example, circularly polarized radio waves, or when linearly polarized waves are used, causes the bottom antenna 160 and the side antenna 161 to radiate radio waves while switching between horizontally polarized waves and vertically polarized waves at high speed. Furthermore, when the bottom antenna 160 and the side antenna 161 receive a response radio wave, the transmitting / receiving unit 214A obtains information including the tag ID from the response radio wave. The transmitter / receiver unit 214A may cause the bottom antenna 160 and the side antenna 161 to radiate radio waves at different times, or may cause the bottom antenna 160 and the side antenna 161 to radiate radio waves simultaneously if mutual interference between the radio waves radiated from the bottom antenna 160 and the side antenna 161 can be ignored.

[0110] As in the RF tag reader 3 according to the second embodiment, in the RF tag reader 5, the radio waves radiated from the bottom antenna 160 are attenuated while propagating through the first attenuation space between the front part 121 and the front storage limiting part 151. In the RF tag reader 5, even if the RF tag 301 is activated by radio waves that pass over the upper end of the front part 121 and leak from the opening 110 to the outside of the storage part 102, the discrimination part 215A can discriminate that the RF tag 301 is outside the storage part 102. Also, in the RF tag reading device 5, the top end of the left side surface portion 122A, the top end of the back surface portion 123B, and the top end of the right side surface portion 124 are higher than the top end of the front surface portion 121. The radio waves radiated from the bottom antenna 160 are attenuated by the time they reach the top end of the left side surface portion 122A, the top end of the back surface portion 123B, and the top end of the right side surface portion 124. In the RF tag reading device 5, even if the RF tag 301 is activated by radio waves that pass over these top ends and leak from the opening 110 to the outside of the storage portion 102, the discrimination unit 215A can discriminate that the RF tag 301 is outside the storage portion 102.

[0111] The configuration of the accommodating unit 102 of the RF tag reader 5 is the same as that of the accommodating unit 102 of the RF tag reader 4. Therefore, hereinafter, the operation of the control unit 201A of the RF tag reader 5 will be described with reference to Figures 18 and 19. However, unlike the above description of Figures 18 and 19, the determination unit 215A determines that the RF tag 301 is inside the accommodating unit 102 based on the RSSI acquired from the response radio wave transmitted by the RF tag 301 that received the radio wave within the range of the diagonal dashed lines slanting upward to the right in Figures 18 and 19, or based on the strength of the response radio wave. When the side antenna 161 receives a response radio wave transmitted from an RF tag 301 that has received radio waves within the range of the diagonal dashed line slanting upward to the right as shown in Figure 18, the discrimination unit 215A determines that the RF tag 301 is inside the storage unit 102 based on the RSSI or the strength of the response radio wave. The radio waves emitted from the side antenna 161 pass over the upper end of the rear portion 123B and the upper end of the right side portion 124 (i.e., the periphery of the opening 110) and leak from the opening 110 to the outside of the storage portion 102. However, the upper end of the rear portion 123B and the upper end of the right side portion 124 are higher than the upper edge of the side antenna 161. The radio waves emitted from the side antenna 161 are attenuated when they reach the upper end of the rear portion 123B and the upper end of the right side portion 124. In the RF tag reading device 5, even if the RF tag 301 is activated by the radio waves that are diffracted at the upper end of the rear portion 123B and the upper end of the right side portion 124 and leak outside the storage portion 102 from the opening 110, the discrimination unit 215A can determine that the RF tag 301 is outside the storage portion 102 based on the RSSI included in the response radio waves received from the RF tag 301 or the strength of the response radio waves.

[0112] Moreover, the radio wave radiated from the side antenna 161 is diffracted upward at the right end of the middle part 1222 of the left side part 122A, and is further diffracted at the upper end of the upper part 1223 and propagates to the left of the storage part 102. However, the strength of the radio wave propagating to the left of the storage part 102 is lower than the strength of the radio wave radiated from the side antenna 161. In the RF tag reading device 5, even if the RF tag 301 is activated by the radio wave radiated from the side antenna 161 and propagating to the left of the storage part 102, the discrimination part 215A can discriminate that the RF tag 301 is outside the storage part 102 based on the RSSI included in the response radio wave received from the RF tag 301 or the strength of the response radio wave.

[0113] When the side antenna 161 receives a response radio wave transmitted from an RF tag 301 that has received radio waves within the range indicated by the diagonal dashed line sloping upward to the right in Figure 19, the discrimination unit 215A determines that the RF tag 301 is inside the storage unit 102 based on the RSSI or the strength of the response radio wave. The radio waves radiated from the side antenna 161 propagate through the first attenuation space between the front portion 121 and the front accommodation limiting portion 151. The radio waves are diffracted at the upper end of the front portion 121 (i.e., the periphery of the opening 110), pass over the upper end of the front portion 121, and leak from the opening 110 to the outside of the accommodation portion 100. The radio waves also leak from the other end of the right side portion 124 (i.e., the opening 110) to the outside of the accommodation portion 102. However, since the radio waves radiated from the side antenna 161 are attenuated while propagating through the first attenuation space between the front portion 121 and the front accommodation limiting portion 151, the intensity of the radio waves leaking to the outside of the accommodation portion 102 is small. In the RF tag reading device 5, even if the RF tag 301 is activated by radio waves leaking outside the storage section 102 from the upper end of the front portion 121 or the other end of the right side portion 124, the discrimination unit 215A can determine that the RF tag 301 is outside the storage section 102 based on the RSSI contained in the response radio waves received from the RF tag 301 or the strength of the response radio waves.

[0114] The acquisition unit 216A identifies each RF tag 301 based on the tag ID included in the information of the RF tag 301 acquired from the response radio waves received by the bottom antenna 160 and the side antenna 161, respectively, and acquires the information for each RF tag 301. For example, when the discrimination unit 215A discriminates that the RF tag 301 is inside the storage unit 102, the acquisition unit 216A acquires information read from the RF tag 301. This enables the RF tag reader 5 to acquire information about the RF tag 301 inside the storage unit 102. The I / F 217A transmits information acquired by the acquisition unit 216A to an external device (such as a checkout device) and receives operation instructions from an external device.

[0115] In addition, the acquisition unit 216A may also acquire information about the RF tag 301 that the discrimination unit 215A has determined to be outside the storage unit 102, and the I / F 217A may transmit the information about the RF tag 301 to an external device together with information indicating whether the RF tag 301 is inside or outside the storage unit 102.

[0116] Seventh embodiment Fig. 21 is a perspective view of an example of an RF tag reader 6 according to a seventh embodiment of the present invention. Fig. 22 is a cross-sectional view taken along line GG in Fig. 21. Fig. 23 is a cross-sectional view taken along line HH in Fig. 21. Fig. 24 is a plan view of an example of a storage section 103 in the RF tag reader 6 of Fig. 21. The RF tag reader 6 includes a storage unit 103 and a control unit 200A. The configuration of a control unit 200A of an RF tag reader 6 according to the seventh embodiment is the same as the configuration of the control unit 200A of an RF tag reader 4 according to the fifth embodiment. The transmitting / receiving unit 211A of the control unit 200A causes the bottom antenna 160 and the side antenna 161 to radiate radio waves of such an intensity that the RF tag 301 outside the housing unit 103 does not activate.

[0117] The storage section 103 has a bottom section 120, a front section 121, a left side section 122B, a rear section 123C, a right side section 124A, a mounting plate 150, a front storage limit plate 151, a side storage limit plate 152, a front guide section 153, a side guide section 154, a bottom antenna 160, and a side antenna 161. In the storage section 103 according to the seventh embodiment, the structure of the left side surface portion 122B and the right side surface portion 124A is different from the structure of the left side surface portion 122A and the right side surface portion 124 of the storage section 102 according to the fifth embodiment. As the structure of the left side surface portion 122B and the left side surface portion 122A is different, the structure of the back surface portion 123C is different from the structure of the back surface portion 123B of the storage section 102, and a side guide portion 154 is added to the storage section 103. In other respects, the configuration of the storage section 103 according to the seventh embodiment is the same as the configuration of the storage section 102 according to the fifth embodiment. Hereinafter, the differences between the storage section 103 and the storage section 102 will be described.

[0118] One end and the other end of the left side surface portion 122B are fixed to one end of the front surface portion 121 and one end of the rear surface portion 123C, respectively. Left side surface portion 122B is made up of lower portion 1221 and middle portion 1222A. Left side surface portion 122B differs from left side surface portion 122A of housing portion 102 in that left side surface portion 122B does not have upper portion 1223 and middle portion 1222A is narrower than middle portion 1222 of housing portion 102. Lower portion 1221 stands perpendicular to bottom portion 120 from the left edge of bottom portion 120. Middle portion 1222A extends parallel to bottom portion 120 from the upper end of lower portion 1221 toward right side portion 124A. A side antenna 161 is provided on the inner surface of the lower portion 1221 of the left side portion 122B. The lower portion 1221 and the middle portion 1222A respectively include a flat plate 1321 and a flat plate 1322A. A radio wave shielding layer 142A covers, for example, the inner surface of the flat plate 1321 and the lower surface of the flat plate 1322A. The lower portion 1221 and the middle portion 1222A do not necessarily need to include the radio wave shielding layer 142A, but it is desirable for the lower portion 1221 and the middle portion 1222A to include the radio wave shielding layer 142A in order to, for example, suppress radio waves from penetrating into the inside of the housing portion 102 from the outside.

[0119] 23, there is a certain gap between the right end of the middle portion 1222A and the side accommodation limiting plate 152. A side guide portion 154 is provided to close the gap. The lower end of the side guide portion 154 is fixed to the upper end of the side accommodation limiting plate 152, extends diagonally upward, and has an upper end fixed to the right end of the middle portion 1222A (i.e., the left side portion 122B) at a position higher than the upper edge of the side antenna 161. The side guide portion 154 transmits radio waves.

[0120] The rear surface portion 123C faces the front surface portion 121. One end and the other end of the rear surface portion 123C are fixed to the other end of the left side surface portion 122B and one end of the right side surface portion 124A, respectively. 17, rear portion 123C is L-shaped and consists of a higher portion closer to the other end and a lower portion closer to one end. However, the length of the lower portion closer to one end is the same as the width of middle portion 1222A. In other words, the length of the lower portion closer to one end of rear portion 123C is shorter than the lower portion closer to one end of rear portion 123B. The back surface portion 123C includes an L-shaped flat plate 133B and an electromagnetic wave absorbing layer 143. The electromagnetic wave absorbing layer 143 covers, for example, the inner surface of the L-shaped flat plate 133B.

[0121] The right side surface portion 124A faces the left side surface portion 122B. Fig. 25 shows an example of the shape of the right side surface portion 124A when the RF tag reader 6 is viewed from the right side. One end of the right side surface portion 124A is fixed to the other end of the back surface portion 123C. The other end of the right side surface portion 124A protrudes a predetermined length toward the front side from the front surface portion 121, and the other end of the front surface portion 121 is fixed between the one end and the other end of the right side surface portion 124A. The right side surface portion 124A has a portion that stands vertically from the right edge of the bottom surface portion 120 relative to the bottom surface portion 120, and a portion that protrudes a predetermined length toward the front side from the front surface portion 121. The right side surface portion 124A includes a flat plate 134A and an electromagnetic wave absorbing layer 144. The electromagnetic wave absorbing layer 144 covers, for example, the inner surface of the flat plate 134A. The upper end of right side surface portion 124A has a constant height from one end to the other end, and the height is the same as the upper end of the other end side of rear surface portion 123C. Therefore, the upper end of right side surface portion 124A is higher than the upper end of front surface portion 121.

[0122] The difference between the structure of the storage unit 103 and the structure of the storage unit 102 causes a difference between the operation of the RF tag reader 6 according to the seventh embodiment and the operation of the RF tag reader 4 according to the fifth embodiment. The following describes the differences between the operation of the RF tag reader 6 and the operation of the RF tag reader 4. Fig. 26 shows an example of radio waves radiated from bottom antenna 160 in RF tag reader 6. However, Fig. 26 shows an example in which lower portion 1221 and middle portion 1222A do not include radio wave shielding layer 142A, and are composed only of flat plate 1321 and flat plate 1322A, respectively. The radio waves radiated upward from the bottom antenna 160 propagate while spreading through the second attenuation space between the left side portion 122B and the side storage limiting plate 152. The space between the right end of the middle portion 1222A and the side storage limiting plate 152 is included in the second attenuation space. The radio waves radiated upward from the bottom antenna 160 are attenuated while propagating through the space between the right end of the middle portion 1222A and the side storage limiting plate 152. In the RF tag reading device 6, the transmitting / receiving unit 211A causes the bottom antenna 160 to radiate radio waves of such intensity that the RF tag 301 outside the storage unit 103 will not operate when the radio waves reach the right end of the middle portion 1222A, for example. Unlike the example of Figure 26, when the lower portion 1221 and the middle portion 1222A include the radio wave shielding layer 142A, the transmitter / receiver 211A radiates to the bottom antenna 160 radio waves of an intensity sufficient to prevent the RF tag 301 outside the storage portion 103 from functioning, by the radio waves propagating through the space between the right end of the middle portion 1222A and the side storage limiting plate 152, diffracting at the right end of the middle portion 1222A and leaking to the left side of the storage portion 103.

[0123] Additionally, the upper end of rear portion 123C and the upper end of right side portion 124A are higher than the upper end of front portion 121. The radio waves radiated from bottom antenna 160 are attenuated by the time they reach the upper end of rear portion 123B and the upper end of right side portion 124A. Transmitter / receiver 211A causes bottom antenna 160 to radiate radio waves of such intensity that RF tag 301 outside storage portion 103 will not function due to the radio waves diffracted at these upper ends and leaking outside storage portion 103.

[0124] Therefore, in the RF tag reading device 6, the radio waves radiated from the bottom antenna 160 are attenuated while propagating through the first attenuation space between the front portion 121 and the front storage limiting portion 151 and the space between the right end of the middle portion 1222A and the side storage limiting plate 152, and because the upper end of the back portion 123C and the upper end of the right side portion 124A are higher than the upper end of the front portion 121, the radio waves radiated from the bottom antenna 160 are attenuated when they reach the upper end of the back portion 123C and the upper end of the right side portion 124A. As a result, the strength of the radio waves radiated from the bottom antenna 160 and leaking outside the storage portion 103 through the opening 110 is reduced, making it possible to obtain information about the RF tag 301 inside the storage portion 103.

[0125] Furthermore, in the RF tag reader 6, the other end of the right side surface portion 124A protrudes a predetermined length toward the front side beyond the front surface portion 121. The radio waves radiated from the side antenna 161 and reaching the other end of the right side surface portion 124A are attenuated. The transmitting / receiving unit 211A causes the side antenna 161 to radiate radio waves of such an intensity that the RF tag 301 outside the storage unit 103 will not operate due to the radio waves that go around the other end of the right side surface portion 124A. Therefore, in the RF tag reading device 6, the radio waves radiated from the side antenna 161 are attenuated while propagating through the first attenuation space between the front portion 121 and the front storage limiting portion 151, the other end of the right side portion 124A protrudes a predetermined length toward the front side beyond the front portion 121, and the upper end of the back portion 123C and the upper end of the right side portion 124A are higher than the upper edge of the side antenna 161, so that the radio waves radiated from the side antenna 161 are attenuated when they reach the upper end of the back portion 123C and the upper end of the right side portion 124A. As a result, the strength of the radio waves radiated from the side antenna 161 and leaking out of the storage portion 103 through the opening 110 is reduced, making it possible to obtain information about the RF tag 301 inside the storage portion 103.

[0126] Incidentally, the width of the middle part 1222A of the left side part 122B is narrow. As shown in Fig. 27, if the radio wave radiated from the side antenna 161 reaches the right end of the middle part 1222A before it has spread sufficiently, it is diffracted at the right end of the middle part 1222A, and the strength of the radio wave that turns around to the left of the storage part 102 is small. Also, the radio wave radiated from the bottom antenna 160 is attenuated while propagating through the space between the right end of the middle part 1222A and the side storage limiting plate 152. For this reason, the storage part 103 of the RF tag reader 6 does not have the upper part 1223 on the left side part 122B.

[0127] In this embodiment, an example is shown in which the left side portion 122B is composed of a lower portion 1221 and a middle portion 1222A.In this case, the right end of the middle portion 1222A is an example of the end portion on the second storage limit portion side of the first side portion of the present invention, and the specified gap between the end portion on the second storage limit portion side and the second storage limit portion in the present invention is the gap between the right end of the middle portion 1222A and the side storage limit plate 152. However, left side portion 122B according to this embodiment may have upper portion 1223 in addition to lower portion 1221 and middle portion 1222A. In this case, the inner surface of upper portion 1223 (which is also the right end of middle portion 1222A) is the end portion on the second accommodation limiting portion side of the first side portion of the present invention, and the specified gap between the end portion on the second accommodation limiting portion side and the second accommodation limiting portion in the present invention is the gap between the inner surface of upper portion 1223 and side accommodation limiting plate 152. Furthermore, left side surface portion 122B may not have middle portion 1222A. That is, left side surface portion 122B may be composed of only lower portion 1221. In this case, the inner surface of lower portion 1221 is the end portion on the second accommodation limiting portion side of the first side surface portion of the present invention, and the predetermined gap between the end portion on the second accommodation limiting portion side and the second accommodation limiting portion in the present invention is the gap between the inner surface of lower portion 1221 and side accommodation limiting plate 152.

[0128] Eighth embodiment Although not shown, the RF tag reader according to the eighth embodiment has a storage unit 103 and a control unit 201A. The configuration of the accommodating unit 103 of the RF tag reader according to the eighth embodiment is the same as the configuration of the accommodating unit 103 of the RF tag reader 6 according to the seventh embodiment. Moreover, the configuration of the control unit 201A of the RF tag reader according to the eighth embodiment is the same as the configuration of the control unit 201A of the RF tag reader 5 according to the sixth embodiment. In the RF tag reader 6 according to the seventh embodiment, the RF tag 301 outside the storage section 103 is not activated by radio waves radiated from the bottom antenna 160 and the side antenna 161 and leaking outside the storage section 103 through the opening 110. In contrast, the radio wave output of the bottom antenna 160 and the side antenna 161 in the RF tag reader according to the eighth embodiment is greater than that of the RF tag reader 6 according to the seventh embodiment. In the RF tag reader according to the eighth embodiment, the RF tag 301 outside the storage unit 103 may be activated by radio waves radiated from the bottom antenna 160 and the side antenna 161 and leaking to the outside of the storage unit 103 through the opening 110. When the discrimination unit 215A receives a response radio wave from the RF tag 301, it discriminates whether the RF tag 301 is inside or outside the storage unit 103 based on the RSSI included in the response radio wave or the strength of the response radio wave.

[0129] In the accommodating section 102 of the RF tag reader 4 according to the fifth embodiment and the RF tag reader 5 according to the sixth embodiment, the other end of the right side surface portion 124 is fixed to the other end of the front surface portion 121. In contrast, like the accommodating section 103 of the RF tag reader 6 according to the seventh embodiment and the RF tag reader according to the eighth embodiment, the accommodating section 102 may also be configured so that the other end of the right side surface portion 124 protrudes a predetermined length toward the front side beyond the front surface portion 121, and the other end of the front surface portion 121 is fixed between the other end and one end of the right side surface portion 124. In the RF tag reader 6 according to the seventh embodiment and the accommodating section 103 according to the eighth embodiment, the other end of the right side surface portion 124A protrudes a predetermined length toward the front side beyond the front surface portion 121, and the other end of the front surface portion 121 is fixed between the other end and one end of the right side surface portion 124A. In contrast, like the accommodating section 102 of the RF tag reader 4 according to the fifth embodiment and the RF tag reader 5 according to the sixth embodiment, the accommodating section 103 can also be configured such that the other end of the right side surface portion 124A is fixed to the other end of the front surface portion 121.

[0130] Ninth embodiment Fig. 28 is a perspective view of an example of an RF tag reader 7 according to a ninth embodiment of the present invention. Fig. 29 is a cross-sectional view taken along line II in Fig. 28. Fig. 30 is a cross-sectional view taken along line JJ in Fig. 28. Fig. 31 is a plan view of an example of a storage section 104 in the RF tag reader 7 of Fig. 28. The RF tag reader 7 according to the ninth embodiment is obtained by adding a front antenna 162 to the RF tag reader 4 according to the fifth embodiment. The RF tag reader 7 includes a storage unit 104 and a control unit 200B.

[0131] As shown in Figures 28 to 31, the storage section 104 has a bottom section 120, a front section 121, a left side section 122A, a rear section 123B, a right side section 124, a mounting plate 150, a front storage limiting plate 151, a side storage limiting plate 152, a front guide section 153, a bottom antenna 160, a side antenna 161, and a front antenna 162. The storage unit 104 of the RF tag reader 7 according to the ninth embodiment differs from the storage unit 102 of the RF tag reader 4 according to the fifth embodiment in that it has a front antenna 162. In other respects, the configuration of the storage unit 104 according to the ninth embodiment is the same as the configuration of the storage unit 102 according to the fifth embodiment. The differences between the storage unit 104 and the storage unit 102 will be described below.

[0132] The front antenna 162 is an antenna installed on the inner surface of the front part 121. The front antenna 162 radiates radio waves for communicating with the RF tag 301 toward the direction of the rear part 123B, and receives response radio waves transmitted from the RF tag 301. The front antenna 162 is, for example, a planar antenna or a sheet antenna. The front antenna 162 radiates, for example, circularly polarized radio waves, or radiates radio waves while switching between horizontally polarized waves and vertically polarized waves.

[0133] The upper end of left side surface portion 122A (i.e., the upper end of upper portion 1223), the upper end of rear surface portion 123B, and the upper end of right side surface portion 124 are higher than the upper edge of front antenna 162. Here, the upper edge of front antenna 162 refers to the highest position of the portion of front antenna 162 that radiates radio waves. It should be noted that no antenna for emitting radio waves for communicating with the RF tag 301 is provided on the rear surface 123B and the right side surface 124.

[0134] A control unit 200B of an RF tag reader 7 according to the ninth embodiment differs from the control unit 200A of an RF tag reader 4 according to the fifth embodiment in that the control unit 200B controls the front antenna 162. In other respects, the operation of the control unit 200B is the same as the operation of the control unit 200A. The control unit 200B includes a transmission / reception unit 211B, an acquisition unit 212B, and an I / F (interface) 213B. The transmitting / receiving unit 211B controls the front antenna 162 in addition to the bottom antenna 160 and the side antenna 161. The transmitting / receiving unit 211B causes the bottom antenna 160, the side antenna 161, and the front antenna 162 to radiate, for example, circularly polarized radio waves, or when linear polarization is used, causes the bottom antenna 160, the side antenna 161, and the front antenna 162 to radiate radio waves while switching between horizontal polarization and vertical polarization at high speed. Furthermore, when the bottom antenna 160, the side antenna 161, and the front antenna 162 receive a response radio wave, the transmitting / receiving unit 211B obtains information including the tag ID from the response radio wave. The transmission / reception unit 211B may radiate radio waves from bottom antenna 160, side antenna 161, and front antenna 162 at different times, or may radiate radio waves simultaneously from bottom antenna 160, side antenna 161, and front antenna 162 if mutual interference between the radio waves radiated from bottom antenna 160, side antenna 161, and front antenna 162 can be ignored.

[0135] The RF tag 301 obtains the power necessary to operate by receiving radio waves transmitted from one or more of the bottom antenna 160, the side antenna 161, and the front antenna 162. If the strength of the radio waves received by the RF tag 301 is less than a predetermined value, the RF tag 301 does not operate and does not transmit a response radio wave. The radio waves radiated from the front antenna 162 pass over the upper end of the left side surface portion 122A (i.e., the upper end of the upper portion 1223), the upper end of the back surface portion 123B, and the upper end of the right side surface portion 124 (i.e., the periphery of the opening 110), and leak from the opening 110 to the outside of the housing portion 104. However, the upper end of the left side surface portion 122A, the upper end of the back surface portion 123B, and the upper end of the right side surface portion 124 are higher than the upper edge of the front antenna 162. The radio waves radiated from the front antenna 162 are attenuated by the time they reach the upper end of the left side surface portion 122A, the upper end of the back surface portion 123B, and the upper end of the right side surface portion 124. Therefore, the strength of the radio waves radiated from the front antenna 162 and leaking from the opening 110 to the outside of the housing portion 104 is reduced. The transmitting / receiving unit 211B causes the front antenna 162 to radiate radio waves of such intensity that the RF tag 301 outside the storage unit 104 will not be activated by radio waves that pass over these upper ends and leak out of the storage unit 104 through the opening 110. This enables the RF tag reader 7 to obtain information on the RF tag 301 inside the storage unit 104 (i.e., the storage space).

[0136] FIG. 32 is a diagram for explaining an example of the effect of the RF tag reader 7 according to the ninth embodiment. 32, there are six RF tags 301 inside the storage section 104. Each RF tag 301 is parallel to the bottom antenna 160 and stacked vertically, with their longitudinal directions facing the front antenna 162. In this case, the RF tags 301 located at the top have a harder time receiving radio waves radiated from the bottom antenna 160. Moreover, since the longitudinal direction of each RF tag 301 faces the front antenna 162, it is also harder for each RF tag 301 to receive radio waves radiated from the front antenna 162. However, each RF tag 301 receives radio waves radiated from the side antenna 161 and transmits a response radio wave to the side antenna 161. Therefore, the acquisition unit 212B can acquire information on the six RF tags 301 from the response radio waves received by the side antenna 161. A situation in which multiple RF tags 301 are parallel to the bottom antenna 160, stacked vertically, and with their longitudinal directions facing the side antenna 161 or the front antenna 162 may occur, for example, when RF tags 301 are attached to a thin article 300 such as clothing or an envelope. According to the RF tag reader 7 of the ninth embodiment, antenna radio waves are emitted to the RF tag 301 in the storage unit 104 from three directions perpendicular to each other. Therefore, the RF tag reader 7 is less likely to fail to read the information of the RF tag 301 in the storage unit 104.

[0137] Note that rear portion 123B includes radio wave absorbing layer 143. If rear portion 123B included a radio wave reflecting layer, radio waves emitted from front antenna 162 would be reflected by rear portion 123B, and the reflected waves would pass over the upper end of front portion 121 and leak out of housing portion 104. The upper end of front portion 121 is low. Therefore, the strength of the reflected waves may be large. Therefore, it is essential that rear portion 123B includes radio wave absorbing layer 143.

[0138] (Tenth embodiment) 33 is a vertical cross-sectional view of an example of an RF tag reader 8 according to a tenth embodiment of the present invention. Fig. 33 corresponds to a cross-sectional view taken along line JJ in Fig. 28. The RF tag reader 8 according to the tenth embodiment is obtained by adding a front antenna 162 to the RF tag reader 5 according to the sixth embodiment. The RF tag reader 8 includes a storage unit 104 and a control unit 201B. The configuration of the accommodating section 104 of the RF tag reader 8 according to the tenth embodiment is the same as the configuration of the accommodating section 104 of the RF tag reader 7 according to the ninth embodiment. The radio wave outputs of the bottom antenna 160, the side antenna 161, and the front antenna 162 in the RF tag reader 8 according to the tenth embodiment are greater than those in the RF tag reader 7 according to the ninth embodiment. In the RF tag reader 8 according to the tenth embodiment, the RF tag 301 outside the storage section 104 may be activated by radio waves leaking to the outside from the opening 110.

[0139] A control unit 201B of an RF tag reader 8 according to the tenth embodiment differs from the control unit 201A of an RF tag reader 5 according to the sixth embodiment in that the control unit 201B controls the front antenna 162. Regarding the control of the bottom antenna 160 and the side antenna 161, the operation of the control unit 201B is the same as that of the control unit 201A. The control unit 201B has a transmission / reception unit 214B, a determination unit 215B, an acquisition unit 216B, and an I / F (interface) 217B. The transmitting / receiving unit 214B controls the front antenna 162 in addition to the bottom antenna 160 and the side antenna 161. The transmitting / receiving unit 214B causes the bottom antenna 160, the side antenna 161, and the front antenna 162 to radiate, for example, circularly polarized radio waves, or when linear polarization is used, causes the bottom antenna 160, the side antenna 161, and the front antenna 162 to radiate radio waves while switching between horizontal polarization and vertical polarization at high speed. Furthermore, when the bottom antenna 160, the side antenna 161, and the front antenna 162 receive a response radio wave, the transmitting / receiving unit 214B obtains information including the tag ID from the response radio wave. The transmitter / receiver unit 214B may radiate radio waves from bottom antenna 160, side antenna 161, and front antenna 162 at different times, or may radiate radio waves from bottom antenna 160, side antenna 161, and front antenna 162 simultaneously if mutual interference between the radio waves radiated from bottom antenna 160, side antenna 161, and front antenna 162 can be ignored.

[0140] The radio waves radiated from the front antenna 162 pass over the upper end of the left side surface portion 122A (i.e., the upper end of the upper portion 1223), the upper end of the rear portion 123B, and the upper end of the right side surface portion 124, and leak from the opening 110 to the outside of the housing portion 104. However, the upper end of the upper portion 1223, the upper end of the rear portion 123B, and the upper end of the right side surface portion 124 are higher than the upper edge of the front antenna 162. The radio waves radiated from the front antenna 162 are attenuated by the time they reach the upper end of the upper portion 1223, the upper end of the rear portion 123B, and the upper end of the right side surface portion 124. For this reason, the strength of the radio waves radiated from the front antenna 162 and leaking from the opening 110 to the outside of the housing portion 104 decreases. In the RF tag reading device 8, even if the RF tag 301 is activated by radio waves that pass over the upper end of the upper portion 1223, the upper end of the back portion 123B, and the upper end of the right side portion 124 and leak through the opening 110 to the outside of the storage portion 104, the discrimination unit 215B can determine that the RF tag 301 is outside the storage portion 104 based on the RSSI contained in the response radio waves received from the RF tag 301 or the strength of the response radio waves.

[0141] The acquisition unit 216B identifies each RF tag 301 based on the tag ID contained in the information of the RF tag 301 acquired from the response radio waves received by the bottom antenna 160, the side antenna 161, and the front antenna 162, respectively, and acquires the information for each RF tag 301. For example, when the determination unit 215B determines that the RF tag 301 is inside the storage unit 104 (i.e., inside the storage space), the acquisition unit 216B acquires information read from the RF tag 301. This enables the RF tag reader 8 to acquire information about the RF tag 301 inside the storage space. The I / F 217B transmits information acquired by the acquisition unit 216B to an external device (such as a checkout device) and receives operation instructions from the external device.

[0142] In addition, the acquisition unit 216B may also acquire information about the RF tag 301 that the discrimination unit 215B has determined to be outside the storage unit 104, and the I / F 217B may transmit the information about the RF tag 301 to an external device together with information indicating whether the RF tag 301 is inside or outside the storage unit 104.

[0143] (Eleventh embodiment) Fig. 34 is a perspective view of an example of an RF tag reader 9 according to an eleventh embodiment of the present invention. Fig. 35 is a cross-sectional view taken along line KK in Fig. 34. Fig. 36 is a cross-sectional view taken along line LL in Fig. 34. Fig. 37 is a plan view of an example of a storage section 105 in the RF tag reader 9 of Fig. 34. The RF tag reader 9 according to the eleventh embodiment is configured by adding a front antenna 162 to the RF tag reader 6 according to the seventh embodiment. The RF tag reader 9 includes a storage unit 105 and a control unit 200B. The configuration of the control unit 200B of the RF tag reader 9 according to the 11th embodiment is the same as the configuration of the control unit 200B of the RF tag reader 7 according to the 9th embodiment. The transmitting / receiving unit 211B of the control unit 200B causes the bottom antenna 160, the side antenna 161, and the front antenna 162 to radiate radio waves of an intensity that does not activate the RF tag 301 outside the storage unit 105.

[0144] As shown in Figures 34 to 37, the storage section 105 has a bottom section 120, a front section 121, a left side section 122B, a rear section 123C, a right side section 124A, a mounting plate 150, a front storage limiting plate 151, a side storage limiting plate 152, a front guide section 153, a side guide section 154, a bottom antenna 160, a side antenna 161, and a front antenna 162. The storage unit 105 of the RF tag reader 9 according to the eleventh embodiment differs from the storage unit 103 of the RF tag reader 6 according to the seventh embodiment in that it has a front antenna 162. In other respects, the configuration of the storage unit 105 according to the eleventh embodiment is the same as the configuration of the storage unit 103 according to the seventh embodiment. The differences between the storage unit 105 and the storage unit 103 will be described below.

[0145] The front antenna 162 is an antenna installed on the inner surface of the front part 121. The front antenna 162 is installed at a position where it radiates radio waves with high intensity toward the accommodation space, and radiates radio waves with lower intensity than the radio waves radiated toward the accommodation space, toward a second attenuation space between the left side part 122B and the side accommodation limiting plate 152. The front antenna 162 radiates radio waves for communicating with the RF tag 301 toward the direction of the rear part 123C, and receives a response radio wave transmitted from the RF tag 301. The front antenna 162 is, for example, a planar antenna or a sheet antenna. The front antenna 162 radiates, for example, circularly polarized radio waves, or radiates radio waves while switching between horizontal polarization and vertical polarization.

[0146] The upper end of the rear portion 123C and the upper end of the right side portion 124A are higher than the upper edge of the front antenna 162. It should be noted that no antenna for emitting radio waves for communicating with RF tag 301 is provided on rear surface portion 123C and right side surface portion 124A.

[0147] A control unit 200B of an RF tag reader 9 according to the eleventh embodiment differs from the control unit 200A of the RF tag reader 6 according to the seventh embodiment in that the control unit 200B controls the front antenna 162. In other respects, the operation of the control unit 200B of the RF tag reader 9 is the same as the operation of the control unit 200A of the RF tag reader 6. Furthermore, although the configuration of the control unit 200B of the RF tag reader 9 according to the eleventh embodiment is the same as that of the control unit 200B of the RF tag reader 7 according to the ninth embodiment, a difference between the configuration of the storage unit 105 and the configuration of the storage unit 104 causes a difference in the propagation of the radio waves radiated from the front antenna 162. This difference will be described below.

[0148] The radio waves radiated from the front antenna 162 toward the rear part 123C propagate while spreading through the second propagation space between the left side part 122B and the side accommodation limiting plate 152. The space between the right end of the middle part 1222A and the side accommodation limiting plate 152 is included in the second attenuation space. The radio waves radiated from the front antenna 162 toward the rear part 123C attenuate while propagating through the space between the right end of the middle part 1222A and the side accommodation limiting plate 152. If the lower part 1221 and the middle part 1222A include the radio wave shielding layer 142A, the radio waves are diffracted at the right end of the middle part 1222A of the left side part 122B and leak to the left side of the accommodation part 105. The transmitting / receiving part 211B causes the front antenna 162 to radiate radio waves of such intensity that the RF tag 301 outside the accommodation part 105 does not operate due to the radio waves leaking to the left side of the accommodation part 105. On the other hand, if the lower portion 1221 and the middle portion 1222A do not include the radio wave shielding layer 142A, that is, if the lower portion 1221 and the middle portion 1222A are composed only of flat plate 1321 and flat plate 1322A, respectively, the transceiver unit 211B causes the front antenna 162 to radiate radio waves of an intensity such that the RF tag 301 outside the storage portion 105 will not be activated by the radio waves radiated from the front antenna 162 and reaching the right end of the middle portion 1222A.

[0149] Moreover, the radio waves radiated from the front antenna 162 toward the rear portion 123C pass over the upper end of the rear portion 123C and the upper end of the right side portion 124A (i.e., the periphery of the opening 110) and leak from the opening 110 to the outside of the storage portion 105. However, the upper end of the rear portion 123C and the upper end of the right side portion 124A are higher than the upper edge of the front antenna 162. The radio waves radiated from the front antenna 162 are attenuated by the time they reach the upper end of the rear portion 123C and the upper end of the right side portion 124A. The transmitting / receiving unit 211B causes the front antenna 162 to radiate radio waves of such intensity that the RF tag 301 outside the storage portion 105 does not operate due to the radio waves radiated from the front antenna 162 and leaking to the outside of the storage portion 105 from the upper end of the rear portion 123C and the upper end of the right side portion 124A.

[0150] Therefore, in the RF tag reading device 9, the radio waves radiated from the front antenna 162 are attenuated while propagating through the space between the right end of the middle portion 1222A and the side storage limit plate 152, and because the upper end of the rear portion 123C and the upper end of the right side portion 124A are higher than the upper edge of the front antenna 162, the radio waves radiated from the front antenna 162 are attenuated when they reach the upper end of the rear portion 123C and the upper end of the right side portion 124A. As a result, the strength of the radio waves radiated from the front antenna 162 and leaking out of the storage portion 105 through the opening 110 is reduced, making it possible to obtain information about the RF tag 301 inside the storage portion 105.

[0151] In this embodiment, an example has been shown in which left side surface portion 122B does not have upper portion 1223, but left side surface portion 122B may have upper portion 1223 in addition to lower portion 1221 and middle portion 1222A. Furthermore, left side surface portion 122B may not have middle portion 1222A. In other words, left side surface portion 122B may be composed of lower portion 1221 only.

[0152] (Twelfth embodiment) Although not shown, the RF tag reader according to the twelfth embodiment includes a storage unit 105 and a control unit 201B. The configuration of the storage unit 105 is the same as the configuration of the storage unit 105 of the RF tag reader 9 according to the eleventh embodiment. Moreover, the configuration of the control unit 201B is the same as the configuration of the control unit 201B of the RF tag reader 8 according to the tenth embodiment. In the RF tag reading device 9 of the eleventh embodiment, the RF tag 301 outside the storage section 105 does not function due to radio waves radiated from the bottom antenna 160, side antenna 161, and front antenna 162 and leaking outside the storage section 105 through the opening 110. In contrast, the radio wave outputs of the bottom antenna 160, the side antenna 161, and the front antenna 162 in the RF tag reader according to the 12th embodiment are greater than those of the RF tag reader 9 according to the 11th embodiment. In the RF tag reader according to the 12th embodiment, the RF tag 301 outside the storage unit 105 may be activated by radio waves radiated from the bottom antenna 160, the side antenna 161, and the front antenna 162 and leaking to the outside of the storage unit 105 through the opening 110. When the discrimination unit 215B receives a response radio wave from the RF tag 301, it discriminates whether the RF tag 301 is inside or outside the storage unit 105 based on the RSSI included in the response radio wave or the strength of the response radio wave.

[0153] In the accommodating section 104 of the RF tag reader 7 according to the ninth embodiment and the RF tag reader 8 according to the tenth embodiment, the other end of the right side surface portion 124 is fixed to the other end of the front surface portion 121. In contrast, like the accommodating section 105 of the RF tag reader 9 according to the eleventh embodiment and the RF tag reader according to the twelfth embodiment, the accommodating section 104 may also be configured so that the other end of the right side surface portion 124 protrudes a predetermined length toward the front side beyond the front surface portion 121, and the other end of the front surface portion 121 is fixed between the other end and one end of the right side surface portion 124. In the RF tag reader 9 according to the eleventh embodiment and the accommodating section 105 of the RF tag reader according to the twelfth embodiment, the other end of the right side surface portion 124A protrudes a predetermined length toward the front side beyond the front surface portion 121, and the other end of the front surface portion 121 is fixed between the other end and one end of the right side surface portion 124A. In contrast, like the accommodating section 104 of the RF tag reader 7 according to the ninth embodiment and the RF tag reader 8 according to the tenth embodiment, the accommodating section 105 can also be configured such that the other end of the right side surface portion 124A is fixed to the other end of the front surface portion 121.

[0154] In addition, in the RF tag reading device of the present invention, it is possible to appropriately combine a configuration in which the RF tag 301 outside the storage unit does not operate and does not transmit response radio waves, and a configuration in which the RF tag 301 outside the storage unit operates and transmits response radio waves, but the discrimination unit discriminates that the RF tag 301 is outside based on the RSSI or the strength of the response radio waves. For example, the configuration can be such that the RF tag 301 outside the storage section does not operate in response to the radio waves radiated from the bottom antenna 160 and does not transmit a response radio wave, and the RF tag 301 outside the storage section operates in response to the radio waves radiated from the front antenna 162 and the side antenna 161 and transmits a response radio wave, but the discrimination section determines that the RF tag 301 is outside.

[0155] In the above embodiment, an example in which one bottom antenna is provided on the bottom surface is shown, but two or more bottom antennas may be provided on the bottom surface. Similarly, two or more front antennas may be provided on the front surface, and two or more side antennas may be provided on the left side surface.

[0156] In addition, in the above-described embodiment, an example was shown in which the left side surface portion is the first side surface portion of the present invention and the right side surface portion is the second side surface portion of the present invention, but the right side surface portion may be the first side surface portion of the present invention and the left side surface portion may be the second side surface portion of the present invention.

[0157] In the above-described embodiment, the RF tag reader and the RF tag communicate with each other using radio waves in the UHF band of 860 to 960 MHz. However, the RF tag reader and the RF tag may communicate with each other using radio waves of other frequencies.

[0158] In addition, in the above-described embodiment, a product has been described as an example, but the product is not limited to a product, and may be other items such as samples, documents, medicines, etc. The RF tag reader according to the present invention can be used for other purposes as well as for self-checkouts.

[0159] As described above, according to the present invention, in an RF tag reading device that has an opening at the top of a storage section and acquires information from a passive RF tag inside the storage section when the opening is open, it is possible to prevent erroneous acquisition of information from an RF tag outside the storage section due to diffraction of radio waves at the periphery of the opening.

[0160] Furthermore, although the top end of the front part of the RF tag reading device of the present invention is lower than the top ends of the left side part and the right side part, even if a side antenna is installed on the left or right side part, strong radio waves do not leak beyond the front part through the opening to the outside of the storage unit, and information will not be erroneously read from an RF tag outside the storage unit.

[0161] Furthermore, because the upper end of the front part of the storage unit of the RF tag reader according to the present invention is low, items and shopping baskets can be easily inserted and removed from the storage unit by inserting and removing them from the front side. By providing a front guide part and a side guide part on the front part and the left side part of the storage unit, respectively, it becomes even easier to insert and remove items and shopping baskets.

[0162] Although the embodiments of the present invention have been described above, various modifications and combinations required due to convenience in design or manufacturing or other factors are included within the scope of the invention described in the claims and the invention corresponding to the specific examples described in the embodiments of the invention. [Explanation of symbols]

[0163] 1, 1A, 3, 4, 5, 6, 7, 8, 9... RF tag reader of the present invention, 2... RF tag reader of comparative example, 100, 100A, 102, 103, 104, 105... storage section of the present invention, 101... storage section of comparative example, 110... opening, 120... bottom surface portion, 121... front portion, 122, 122A, 122B, 122C... left side surface portion, 1221... lower part of left side surface portion, 122 2, 1222A...middle part of the left side part, 1223...upper part of the left side part, 123, 123B, 123C...back part, 123A...back part of the comparative example, 124, 124A...right side part, 130, 131, 132, 132A, 133, 133A, 133B, 134, 134A...flat plate, 1321, 1322, 1322A, 1323...flat plate included in the left side part, 140, 1 41, 142A...radio wave shielding layer, 142, 143, 144...radio wave absorbing layer, 143A...radio wave reflecting layer, 150...mounting plate, 151...front accommodation limiting plate, 152...side accommodation limiting plate, 153...front guide portion, 154...side guide portion, 160...bottom antenna, 161...side antenna, 162...front antenna, 200, 200A, 200B, 201, 201A, 20 1B...control unit, 211, 211A, 211B, 214, 214A, 214B...transmitting / receiving unit, 215, 215A, 215B...discrimination unit, 212, 212A, 212B, 216, 216A, 216B...acquisition unit, 213, 213A, 213B, 217, 217A, 217B...I / F (interface), 300...item, 301...RF tag, 400...shopping basket

Claims

1. An RF tag reading device that includes a storage unit having an opening at an upper portion through which an article having a passive RF tag attached thereto can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom portion and a front portion on which an antenna for communicating with the RF tag is not installed; a first side portion having one end fixed to one end of the front portion, the first side portion not having an antenna for communicating with the RF tag; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion, one end and the other end of which are fixed to the other end of the back portion and the other end of the front portion, respectively, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being installed, and the upper end of the second side portion being higher than the upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves having a high intensity toward the accommodation space and radiates radio waves having a lower intensity than the radio waves radiated toward the accommodation space toward the first attenuation space; An RF tag reading device comprising:

2. the first side portion includes an electromagnetic wave absorbing layer; an upper end of the first side surface portion is higher than an upper end of the front surface portion; The radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and the top end of the first side portion, the top end of the back portion, and the top end of the second side portion are higher than the top end of the front portion, and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the first side portion, the top end of the back portion, and the top end of the second side portion. This reduces the strength of the radio waves radiated from the bottom antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

2. The RF tag reader according to claim 1.

3. a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; the bottom antenna is disposed at a position where it radiates toward the second attenuation space a radio wave having a strength weaker than that of the radio wave radiated toward the accommodation space, The radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space and the second attenuation space, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper end of the front portion, and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion. This reduces the strength of the radio waves radiated from the bottom antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

2. The RF tag reader according to claim 1.

4. An RF tag reading device as described in claim 1, further comprising a third storage limiting section located above the bottom portion, which divides the interior of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not stored and in which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space.

5. An RF tag reading device that includes a storage unit having an opening at an upper portion through which an article having a passive RF tag attached thereto can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom surface portion including an electromagnetic wave absorbing layer and / or an electromagnetic wave reflecting layer; a front portion on which an antenna for communicating with the RF tag is not installed; a first side portion having one end fixed to one end of the front portion; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion and having one end fixed to the other end of the back portion, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided, and the second side portion having an upper end higher than an upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves having a high intensity toward the accommodation space and radiates radio waves having a lower intensity than the radio waves radiated toward the accommodation space toward the first attenuation space; a side antenna disposed on an inner surface of the first side portion at a position that radiates radio waves having a high intensity toward the accommodation space and radiates radio waves having a lower intensity than the radio waves radiated toward the accommodation space toward the first attenuation space; An RF tag reading device comprising:

6. the first side portion is composed of a lower portion, a middle portion and an upper portion, the lower portion standing upright from an edge of the bottom portion, the side antenna is installed in the lower portion, the lower portion and the middle portion include a radio wave absorbing layer and / or a radio wave reflecting layer, the upper portion stands upright from an upper end of the second accommodation limiting portion, the upper portion includes a radio wave absorbing layer, and the upper end of the upper portion is higher than the upper end of the front portion, The radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and the top end of the upper part, the top end of the back part, and the top end of the second side part are higher than the top end of the front part, and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the upper part, the top end of the back part, and the top end of the second side part. This reduces the strength of the radio waves radiated from the bottom antenna and leaking outside the storage section through the opening, making it possible to obtain information from an RF tag inside the storage space.

6. The RF tag reader according to claim 5.

7. the first side portion has at least a lower portion, the lower portion stands upright from an edge of the bottom portion, the side antenna is installed on the lower portion, and there is a predetermined gap between an end portion of the first side portion on the side of the second accommodation limiting portion and the second accommodation limiting portion; the bottom antenna is disposed at a position where it radiates toward the second attenuation space a radio wave having a strength weaker than that of the radio wave radiated toward the accommodation space, The radio waves radiated from the bottom antenna are attenuated while propagating through the space between the end and the second accommodation limiting portion, which are included in the first attenuation space and the second attenuation space, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper end of the front portion, and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion. This reduces the strength of the radio waves radiated from the bottom antenna and leaking out of the accommodation portion through the opening, making it possible to obtain information from an RF tag inside the accommodation space.

6. The RF tag reader according to claim 5.

8. the other end of the second side surface portion is fixed to the other end of the front surface portion, The radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, and the upper end of the back portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the back portion and the upper end of the second side portion. This reduces the intensity of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

8. The RF tag reader according to claim 6 or 7.

9. The other end of the second side surface portion protrudes toward the front side by a predetermined length beyond the front surface portion, and the other end of the front surface portion is fixed between the other end and one end of the second side surface portion, The radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, the other end of the second side portion protrudes a predetermined length toward the front side beyond the front portion, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion. This reduces the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

8. The RF tag reader according to claim 6 or 7.

10. An RF tag reading device as described in claim 5, further comprising a third storage limiting section located above the bottom portion, which divides the interior of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not stored and in which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space.

11. An RF tag reading device that includes a storage unit having an opening at an upper portion through which an article having a passive RF tag attached thereto can be inserted and removed, and that reads information from an RF tag attached to an article stored inside the storage unit with the opening open, A bottom surface portion including an electromagnetic wave absorbing layer and / or an electromagnetic wave reflecting layer; The front part and a first side portion having one end fixed to one end of the front portion; a rear portion facing the front portion, one end of which is fixed to the other end of the first side portion, the rear portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided thereon, and an upper end of the rear portion being higher than an upper end of the front portion; a second side portion facing the first side portion and having one end fixed to the other end of the back portion, the second side portion including an electromagnetic wave absorbing layer, no antenna for communicating with the RF tag being provided, and the second side portion having an upper end higher than an upper end of the front portion; a first storage limiting portion located between the front portion and the rear portion, the first storage limiting portion dividing the interior of the storage portion into a space between the front portion and the first storage limiting portion which is a first damping space in which the item is not stored, and a space between the first storage limiting portion and the rear portion which is a storage space in which the item can be stored; a second storage limiting portion located between the first side portion and the second side portion, the second storage limiting portion dividing the interior of the storage portion into a space between the first side portion and the second storage limiting portion which is a second damping space in which the item is not stored, and a space between the second storage limiting portion and the second side portion which is the storage space; a bottom antenna disposed on an upper surface of the bottom portion at a position that radiates radio waves having a high intensity toward the accommodation space and radiates radio waves having a lower intensity than the radio waves radiated toward the accommodation space toward the first attenuation space; a side antenna disposed on an inner surface of the first side portion at a position that radiates radio waves having a high intensity toward the accommodation space and radiates radio waves having a lower intensity than the radio waves radiated toward the accommodation space toward the first attenuation space; a front antenna disposed on an inner surface of the front portion; An RF tag reading device comprising:

12. the first side portion is composed of a lower portion, a middle portion and an upper portion, the lower portion standing upright from an edge of the bottom portion, the side antenna is installed in the lower portion, the lower portion and the middle portion include a radio wave absorbing layer and / or a radio wave reflecting layer, the upper portion stands upright from an upper end of the second accommodation limiting portion, the upper portion includes a radio wave absorbing layer, and the upper end of the upper portion is higher than the upper end of the front portion, Because the radio waves radiated from the bottom antenna are attenuated while propagating through the first attenuation space, and because the top end of the upper part, the top end of the back part, and the top end of the second side part are higher than the top end of the front part, and the radio waves radiated from the bottom antenna are attenuated when they reach the top end of the upper part, the top end of the back part, and the top end of the second side part, the strength of the radio waves radiated from the bottom antenna and leaking outside the storage section through the opening is reduced, making it possible to obtain information from an RF tag inside the storage space, the upper end of the upper portion, the upper end of the rear portion, and the upper end of the second side portion are higher than the upper edge of the front antenna, and the radio waves radiated from the front antenna are attenuated when they reach the upper end of the upper portion, the upper end of the rear portion, and the upper end of the second side portion, thereby reducing the intensity of the radio waves radiated from the front antenna and leaking out of the storage section through the opening, making it possible to obtain information from an RF tag inside the storage space. The RF tag reader according to claim 11.

13. the first side portion has at least a lower portion, the lower portion stands upright from an edge of the bottom portion, the side antenna is installed on the lower portion, and there is a predetermined gap between an end portion of the first side portion on the side of the second accommodation limiting portion and the second accommodation limiting portion; the bottom antenna is disposed at a position where it radiates toward the second attenuation space a radio wave having a strength weaker than that of the radio wave radiated toward the accommodation space, The radio waves radiated from the bottom antenna are attenuated while propagating through the space between the end and the second accommodation limiting portion, which are included in the first attenuation space and the second attenuation space, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper end of the front portion, and the radio waves radiated from the bottom antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion. As a result, the strength of the radio waves radiated from the bottom antenna and leaking out of the accommodation portion through the opening is reduced, making it possible to obtain information from an RF tag inside the accommodation space, the front antenna is installed at a position where it radiates radio waves with a high intensity toward the accommodation space and radiates radio waves with an intensity lower than that of the radio waves radiated toward the accommodation space toward the second attenuation space, The radio waves radiated from the front antenna are attenuated while propagating through the space between the end included in the second attenuation space and the second accommodation limiting section, and the upper end of the rear section and the upper end of the second side section are higher than the upper edge of the front antenna, and the radio waves radiated from the front antenna are attenuated when they reach the upper end of the rear section and the upper end of the second side section. This reduces the intensity of the radio waves radiated from the front antenna and leaking out of the accommodation section through the opening, making it possible to obtain information from an RF tag inside the accommodation space. The RF tag reader according to claim 11.

14. the other end of the second side surface portion is fixed to the other end of the front surface portion, The radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, and the upper end of the back portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the back portion and the upper end of the second side portion. This reduces the intensity of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

14. The RF tag reader according to claim 12 or 13.

15. The other end of the second side surface portion protrudes toward the front side by a predetermined length beyond the front surface portion, and the other end of the front surface portion is fixed between the other end and one end of the second side surface portion, The radio waves radiated from the side antenna are attenuated while propagating through the first attenuation space, the other end of the second side portion protrudes a predetermined length toward the front side beyond the front portion, and the upper end of the rear portion and the upper end of the second side portion are higher than the upper edge of the side antenna, and the radio waves radiated from the side antenna are attenuated when they reach the upper end of the rear portion and the upper end of the second side portion. This reduces the strength of the radio waves radiated from the side antenna and leaking out of the storage portion through the opening, making it possible to obtain information from an RF tag inside the storage space.

14. The RF tag reader according to claim 12 or 13.

16. The RF tag reading device of claim 11, further comprising a third storage limiting section located above the bottom portion, which divides the interior of the storage section into a space between the bottom portion and the third storage limiting section, in which the item is not stored and in which the radio waves radiated from the bottom antenna propagate while spreading, and a space above the third storage limiting section, which is the storage space.

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