Patent Publication Number: US-2009237217-A1

Title: Packaging box, packaging material, tag id reading method, and tag id transmitting program

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the conventional priority based on Japanese Patent Application No. 2008-073551, filed on Mar. 21, 2008, the disclosures of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     One embodiment of the present invention relates to a packaging box, a packaging material, a tag ID reading method, and a tag ID transmitting program, which may include a packaging box, a packaging material, a tag ID reading method, and a tag ID transmitting program in which an RFID tag which does not face an antenna can be detected. 
     2. Description of the Related Art 
     When an RFID tag receives radio waves transmitted from a reader, the RFID tag returns its ID to the reader as a response. Based on the mechanism, products and packaging boxes are managed to which the RFID tags are attached. 
     For example, a packaging box has been proposed which has an IC tag that communicate in a non-contact manner by using radio waves and is provided on the outside of the box, and has reflection means that reflects the radio waves and is provided on the inside of the box (see Japanese Patent Laid-Open No. 2006-224972). 
     When the RFID tag is used, radio waves is transmitted and received between an antenna of the reader and the RFID tag. Thus, the RFID tag desirably faces the antenna. However, from various reasons, when a packaging box containing products is transported, the RFID tag thereof is not necessarily face the antenna. 
     Further, when a material which absorbs (or reflects) radio waves (wave absorber or wave reflector) exists between or around the antenna of the reader and the RFID tag, the RFID tag is blocked from the radio waves transmitted from the antenna. Thus, the RFID can not detect a signal from the reader. 
     Especially, a corrugated board, which is mainly used for a packaging box, easily absorbs water. Accordingly, the corrugated board sometimes shows characteristics near to a conductor or characteristics of a wave absorber. For this reason, the corrugated board functions as the wave absorber when it moistens in the rain or in a highly humid environment, so that communication between the antenna and the RFID tag becomes unstable. 
     SUMMARY OF THE INVENTION 
     One aspect of an object of the present invention is to provide a packaging box in which an RFID tag which does not face an antenna can be detected. 
     Another aspect of the object of the present invention is to provide a packaging material which is used for setting up a packaging box in which an RFID tag which does not face an antenna can be detected. 
     Yet another aspect of the object of the present invention is to provide a tag ID reading method in which an RFID tag which does not face an antenna can be detected. 
     Yet another aspect of the object of the present invention is to provide a tag ID transmitting program in which an RFID tag which does not face an antenna can be detected. 
     The packaging box includes a body having a top surface, a base and a side, first and second signal conductors, and an RFID tag. The first signal conductor is provided on a first region on an outside of the body. The second signal conductor is provided on a second region on the outside of the body and electrically insulated from the first signal conductor. The RFID tag is attached to a third region on an outside of the side as being electrically insulated from the first and second signal conductors with a first electrode thereof connected to the first signal conductor and a second electrode thereof connected to the second signal conductor. 
     The packaging box has the RFID tag which further includes a connection circuit, a memory circuit, an antenna circuit, and a tag ID shared circuit. The connection circuit is connected to the first and second signal conductors via the first and second electrodes. The memory circuit stores one or more tag IDs including at least the tag ID of the RFID tag. The antenna circuit transmits/receives a signal to/from a reader. The tag ID shared circuit causes the one or more tag IDs stored in the memory circuit to be transmitted to the reader via the antenna circuit. 
     The packaging box has the one or more tag IDs which are stored in the memory circuit and include the tag ID of the RFID tag of the other RFID tags which is connected to the RFID tag via the first or second signal conductor. 
     The packaging material includes a body, a first signal conductor, a second signal conductor, and a third region. The body has faces to make a top surface, a base and a side of a packaging box which is to be set up with the packaging material. The first signal conductor is provided on a first region of each of the faces which is to make an outside of the packaging box which is to be set up with the packaging material. The second signal conductor is provided on a second region of each of the faces which is to make the outside and electrically insulated from the first signal conductor. The third region is a region provided on the face which is to make the outside of the side of the packaging box which is to be set up with the packaging material. The third region is available for an RFID tag to be attached thereto as the RFID tag is being electrically insulated from the first and second signal conductors with a first electrode thereof connected to the first signal conductor and a second electrode thereof connected to the second signal conductor. 
     The tag ID reading method is a tag ID reading method for reading tag IDs from a plurality of RFID tags by a reader in an aggregate of a plurality of piled up packaging boxes. Each of the packaging boxes includes a body having a top surface, a base and a side, a first signal conductor provided on a first region on an outside of the body, a second signal conductor provided on a second region on the outside of the body with electrically insulated from the first signal conductor, and an RFID tag attached to a third region on an outside of the side as being electrically insulated from the first and second signal conductors with a first electrode thereof connected to the first signal conductor and a second electrode thereof connected to the second signal conductor. In the tag ID reading method, the RFID tags of the packaging boxes of the plurality of packaging boxes transmit/receive the tag IDs thereof where the RFID tags have the first and second electrodes thereof contact each other, the RFID tag that receives the tag ID from the RFID tag of the other RFID tags of the plurality of RFID tags holds the received tag ID, and the RFID tag that can communicate with the reader transmits one or more tag IDs including at least the tag ID of the RFID tag to the reader. 
     The tag ID transmitting program is a tag ID transmitting program for an RFID tag to transmit a tag ID to a reader in an aggregate of a plurality of piled up packaging boxes. Each of the packaging boxes includes a body having a top surface, a base and a side, a first signal conductor provided on a first region on an outside of the body, a second signal conductor provided on a second region on the outside of the body with electrically insulated from the first signal conductor, and an RFID tag attached to a third region on an outside of the side as being electrically insulated from the first and second signal conductors with a first electrode thereof connected to the first signal conductor and a second electrode thereof connected to the second signal conductor. In the tag ID transmitting program, when the RFID tags of the packaging boxes of the plurality of packaging boxes have the first and second electrodes thereof contact each other, the RFID tags transmit/receive the tag IDs thereof, when the RFID tag receives the tag ID from the RFID tag of the other RFID tags, the RFID tag holds the received tag ID, and when the RFID tag can communicate with the reader, the RFID tag transmits one or more tag IDs including at least the tag ID of the RFID tag to the reader. 
     According to the packaging box, an RFID tag which is attached to a packaging box is electrically connected to another RFID tag which is attached to another packaging box as a result of having the first and second signal conductors of the respective packaging boxes contact each other. As a result, information such as the tag ID to be transmitted from a first RFID tag that cannot face the antenna to a second RFID tag that faces the antenna so that the second RFID tag can transmit the information such as the tag ID to the reader. Accordingly, the information such as the tag ID can be read even if the RFID tag does not face the antenna when the packaging box containing products with the RFID tag is transported. Also, the information such as the tag ID can be read even if a wave absorber (or wave reflector) is between or around the antenna of the reader and the RFID tag. In particular, even if the corrugated board which is mainly used for a packaging box absorbs water and takes on the feature of the wave absorber, the communication between the reader and the RFID tag can be kept stable. 
     According to the packaging box in one embodiment, the RFID tag is provided with a connection circuit, a memory circuit, an antenna circuit, and a tag ID shared circuit. As a result, the tag ID of another RFID tag to be stored in the memory circuit of an RFID tag in addition to the self tag ID. 
     According to the packaging box in one embodiment, a first RFID tag includes the tag ID of a second RFID tag. As a result, the tag ID of the second RFID tag to be transmitted to the reader from the first RFID tag. 
     According to the packaging material, the abovementioned packaging box can be easily obtained as a result of setting up the packaging material, and the first and second signal conductors of adjoining packaging boxes can be made contact each other. As a result, the RFID tag which is attached to a packaging box to be electrically connected to the RFID tag which is attached to another packaging box so that the information such as the tag ID can be read even if the RFID tag does not face the antenna or even if a wave absorber (or a wave reflector) is between or around the reader and the RFID tag as mentioned above. 
     According to the tag ID reading method and the tag ID transmitting program, the first and second signal conductors of the adjoining packaging boxes can be made contact each other as a result of using the abovementioned packaging boxes as an aggregate of a plurality of piled up packaging boxes. As a result, the RFID tag which is attached to a packaging box to be electrically connected to the RFID tag which is attached to another packaging box so that the information such as the tag ID can be transmitted and received among the plurality of RFID tags. Consequently, the information such as the tag ID can be read even if the RFID tag does not face the antenna or even if a wave absorber (or a wave reflector) is between or around the reader and the RFID tag as mentioned above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an embodiment of a tag ID reading method and packaging boxes used for the method. 
         FIG. 2  is a development of a packaging material which is to form the packaging box. 
         FIG. 3  is a perspective view of a set up packaging box. 
         FIG. 4  is a schematic diagram of attachment of an RFID tag. 
         FIG. 5  is a diagram illustrating an embodiment of a structure of the RFID tag. 
         FIGS. 6 and 7  are a process flowchart of an RFID tag reading. 
         FIG. 8  is a diagram illustrating another embodiment of the process flowchart of the RFID tag reading. 
         FIG. 9  is a diagram illustrating another embodiment of the tag ID reading method and another embodiment of the packaging boxes used for the method. 
         FIG. 10  is a diagram illustrating a yet another embodiment of the tag ID reading method and a yet another embodiment of the packaging box used for the method. 
         FIG. 11  is a development of a packaging material which is to form the packaging box illustrated in  FIG. 10 . 
         FIG. 12  is a diagram illustrating a yet another embodiment of the tag ID reading method and a yet another embodiment of the packaging box used for the method. 
         FIG. 13  is a development of a packaging material which is to form the packaging box illustrated in  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  illustrates a structure of a tag ID reading system which implements the tag ID reading method according to one embodiment of the present invention, and piled up packaging boxes. 
     The tag ID reading system includes a personal computer (PC)  11  which acts as a controlling device, a connecting device (HUB)  12 , an RFID reader-writer (a reading and writing device, hereinafter simply referred to as a reader in some occasions)  13 , a plurality of antennas  14 , and a cart  15 . The RFID reader-writer  13  is connected to the personal computer  11  via the HUB  12 , and provided with the plurality of antennas  14 . The plurality of antennas  14  are mounted on the single cart  15 . 
     In the embodiment of  FIG. 1 , the reader  13  is to read an aggregate  20  which is a plurality of piled up packaging boxes  21 , specifically, a plurality of RFID tags  3  included in the aggregate  20 . The aggregate  20  is placed on a pallet  16  as a mass of piled up packaging boxes  21 . In the embodiment of  FIG. 1 , the pallet  16  is conductive, and made of a metal plate, for example. The cart  15  is moved along a part of the edge of the pallet  16  as indicated by the arrow in  FIG. 1  by an operator or automatically on a guide rail or the like, for example. 
     The RFID reader-writer  13  transmits (or outputs) a predetermined signal from the plurality of antennas  14 . An RFID tag  3 , which has received the signal from the antennas  14 , transmits a predetermined answer signal to the antennas  14  as a response to the signal. The answer signal includes one or more tag IDs stored in the RFID tag  3 . Then, the RFID reader-writer  13  reads the tag IDs stored in the RFID tag  3 . The RFID reader-writer  13  which has received the answer signal transmits the received answer signal to the personal computer  11  via the HUB  12 . The personal computer  11  which has received the answer signal can detect the packaging boxes  21 , to which the RFID tag  3  is attached, by performing predetermined signal processing. 
     In the embodiment of  FIG. 1 , the aggregate  20  includes a plurality of packaging boxes  21  each of which has a uniform shape. In  FIG. 1 , the aggregate  20  is assumed as including twelve packaging boxes  21 . The twelve packaging boxes  21  in a uniform shape are piled up in a plurality of layers in such a manner that the same faces look the same direction. In the embodiment of  FIG. 1 , the packaging boxes  21  are piled up in two layers. The RFID tag  3  is attached to a side S of each of the packaging boxes  21 . In the embodiment of  FIG. 1 , the face of each of the packaging boxes  21  or the face of the aggregate  20 , to which the RFID tag(s)  3  is attached, is referred to a “front face”. In this case, the RFID tags  3  attached to the front faces of the four packaging boxes  21  face any of the antennas  14  by moving the cart  15 . In other words, no obstacle exists between the RFID tags  3  on the front faces and the antennas  14 , so that the RFID tags  3  see through the antennas  14 . Accordingly, the RFID tags  3  on the front faces can communicate with the RFID reader-writer  13  via the antennas  14 . As a result, the RFID reader-writer  13  can read the tag IDs from the four RFID tags  3  on the front faces. The tag ID of each of the four RFID tags  3 , which are attached to the front faces of the four packaging boxes  21 , is directly read by the RFID reader-writer  13  from each of the RFID tags  3 . 
     In contrast, any of the RFID tags  3  which are attached to the remaining eight packaging boxes  21  cannot see through the antennas  14  because of the presence of the other packaging boxes  21 . In other words, the RFID tags  3 , which are attached to the remaining eight packaging boxes  21 , are attached to places which cannot face the antennas. Accordingly, the RFID reader-writer  13  cannot directly read the tag IDs of the eight RFID tags  3  from those RFID tags  3 . In the embodiment of  FIG. 1 , however, the tag IDs of the eight RFID tags  3  are indirectly read from the four RFID tags  3 , which are attached to the front faces as described later. 
     For simplicity of description, each of the packaging boxes  21  of the aggregate  20  illustrated in  FIG. 1  has its details somewhat omitted (same in  FIGS. 3 ,  9 ,  10  and  12 ). 
       FIG. 2  illustrates a development of a packaging material  21 A which is to form the packaging box  21  according to the embodiment.  FIG. 3  illustrates an appearance of the packaging box  21  according to the embodiment. 
     In  FIG. 2 , a body  210  of the packaging material  21 A includes a face U (faces U 1  to U 4 ) which is to be a top surface of the packaging box  21 , a face L (faces L 1  to L 4 ) which is to be a base of the packaging box  21 , and a face S (faces S 1  to S 4 ) which is to be a side of the packaging box  21 , when the packaging material  21 A is set up to the packaging box  21 . In the description below, the face U which is to be the top surface will be simply referred to as the top surface U. The other faces will also be referred to in the same manner. 
     The packaging material  21 A has a part for paste (pasting part) S 0  to the side S for setting up the packaging box  21 . Since both of a conductor and a insulation film is not provided on the pasting part S 0 , the body  210  of the packaging material  21 A is exposed in that area. 
     The body  210  is made from an electrically insulating material such as a corrugated board, plastics or the like. A first signal conductor  22  and a second signal conductor  23  are provided on the body  210  of the packaging material  21 A. 
     The first signal conductor  22  is used as a first (+) electrode or wiring (hereinafter simply referred to as an electrode). The first signal conductor  22  is provided on a first region R 1  of a face which is to be an outside of the packaging box  21  (hereinafter the face is simply referred to as an outside) in a case that the packaging material  21 A is set up to the packaging box  21 . In the embodiment of  FIG. 1 , the first signal conductor  22  is provided on the sides S of the packaging box  21 . The region on which the first signal conductor  22  is provided is the first region R 1 . The first region R 1  occupies most of the sides S. 
     The second signal conductor  23  is used as a second (−) electrode. The second signal conductor  23  is provided on a second region R 2  of the outside, and is electrically insulated from the first signal conductor  22 . The second signal conductor  23  is provided on both of the top surface U and the base L of the packaging box  21 . The region on which the second signal conductor  23  is provided is the second region R 2 . The second region R 2  occupies most of the top surface U and the base L. 
     The first signal conductor  22  and the second signal conductor  23  are made of dried films of conductive ink, which is painted on the outside of the body  210  which has electric non-conductance. The conductive ink is the ink whose dried film is conductive. The conductive ink contains gold, silver, copper, nickel, conductive carbon powder or the like as a filler, and contains an insulator such as glass frit, polyamide, epoxy, polyester or the like as a binder. 
     The body  210  of the packaging material  21 A includes a third region R 3  as indicated by the dotted line in  FIG. 2 . The third region R 3  is provided on an outside of a side S 2  of the packaging box  21  in a case that the packaging material  21 A is set up to the packaging box  21 . In other words, the third region R 3  is provided on a region in which a part of the first signal conductor  22  is cut out in a part of the side S 2 . The third region R 3  is the region to which the RFID tag  3  is to be attached as described later with reference to  FIGS. 3 and 4 . The third region R 3  includes a connecting conductor  27  and an insulation region  28  for attaching the RFID tag  3 . 
     The connecting conductor  27  is an extended part of the second signal conductor  23  provided on a base L 2 , which is the second region R 2  of the packaging box  21 . The connecting conductor  27  is a continuous region with the second signal conductor  23 . The connecting conductor  27  extrudes from the second signal conductor  23  on the base L 2  into the side S 2 . As a result, the first signal conductor  22  and the connecting conductor  27  are formed on the side S 2  and sandwich the insulation region  28 . 
     The insulation region  28  is the region to which the RFID tag  3  is attached. The RFID tag  3  is attached on the insulation region  28  by an adhesive or the like. The insulation region  28  is made of a dried film of electrically insulating ink painted on the body  210 . The electrically insulating ink is the ink whose dried film is electrically insulating, and is made of a general plastic paint, for example. After the first signal conductor  22  and the second signal conductor  23  are painted and dried, the ink which is to be the insulation region  28  is painted to the packaging material  21 A, and dried. The insulation region  28  may also be simply formed by exposing the body  210  without any painted electrically insulating ink. 
     The packaging material  21 A includes a fourth region R 4  on the outside of the packaging box  21  which is to be the side S 2 . The fourth region R 4  is provided on a region in which a part of the first signal conductor  22  is cut out in a part of the side S 2 . The fourth region R 4  is the region for providing a connecting conductor  25 , which connects the second signal conductors  23  provided on both of the top surface U and the base L of the packaging box  21 . The connecting conductor  25  is provided on the body  210  as illustrated in  FIG. 2  by the same way with the first signal conductor  22  and the second signal conductor  23 . 
     The fourth region R 4  is covered with an insulation cover  26  all of which is made of a insulation film. In other words, the region on which the insulation cover  26  is provided is the fourth region R 4 . The connecting conductor  25  is covered with the insulation cover  26  on the outside of the side S 2  of the packaging box  21 . The first signal conductor  22  and the second signal conductor  23  are electrically insulated from each other by the insulation cover  26  which is made of the insulating ink painted to the body  210 . After the connecting conductor  25  is painted and dried, the insulation cover  26  is provided on the packaging material  21 A as illustrated in  FIG. 2  by the same way with the insulation region  28 . 
     The body  210  of the packaging material  21 A has a fifth region R 5  between the first signal conductor  22  and the second signal conductor  23 , or between the first region R 1  and the second region R 2 . The fifth region R 5  is the region for which electrically insulates the first signal conductor  22  from the second signal conductor  23 . For this reason, an insulator  24  is provided on the fifth region R 5 . In other words, the region on which the insulator  24  is provided is the fifth region R 5 . The first signal conductor  22  is electrically insulated from the second signal conductor  23  by the insulator  24 . The insulator  24  is provided on the packaging material  21 A as illustrated in  FIG. 2  by the same way with the insulation cover  26 , for example. 
     As mentioned above, the packaging box  21  of  FIGS. 2 and 3  is divided into two parts in the vertical direction in a state that the packaging box  21  is placed with the base L downside, and the two signal conductors  22  and  23  is provided in each part of the divided two parts. Specifically, the signal conductor  23  is provided on the top surface U and the base L of the packaging box  21 , and the signal conductor  22  is provided on the side S. As a result of dividing the signal conductors, the packaging box  21  has features as follow. That is, the third region R 3  for which the RFID tag  3  is attached is provided on the packaging box  21 . The fourth region R 4  is provided on the packaging box  21  to connect both of the signal conductors  23  on the top surface U and the base L. The fifth region R 5  is provided on the packaging box  21  to insulate the signal conductor  22  from the signal conductor  23 . 
     The packaging box  21  of  FIG. 3  is set up in the manner described below. The pasting part S 0  on the packaging material  21 A of  FIG. 2  is fixed by pasting, for example, to an inside of a side S 4  which is the other side of the side S. Then, with the pasting part S 0  fixed, both of bases L 1  and L 3  are bent to a predetermined direction or bent inside, and both of base L 2  L 4  are also bent inside. Then, the bent four faces are fixed to each other with staples or the like. After the packaging material  21 A is set up to the packaging box  21 , for example, the RFID tag  3  is attached to the third region R 3  of the packaging box  21 . As a result, the packaging box  21  with the top surface U, which is opened, is obtained. 
     With the top surface U opened, products are packed into the packaging box  21 . Then, both of top surfaces U 1  and U 3  are bent to a predetermined direction or bent inside, and both of top surfaces U 2  and U 4  are also bent inside. The four faces are fixed to each other with staples or the like. As a result, the products have been packed, and the packaging box  21  as illustrated in  FIG. 3  is obtained. 
     In  FIG. 3 , the body  210  of the packaging box  21  has a shape of a rectangular parallelepiped or a cube, and has the top surfaces U, the base L, and the sides S. The base L does not appear in  FIG. 3 . The first signal conductor  22  appears on the first region R 1 , which is one part of the outside of the side S. And, the second signal conductors  23  appear on the second regions R 2 , which is the outside of the top surface U and the base L. The second signal conductors  23  on the top surface U and the base L are connected to each other by the connecting conductor  25  which is provided on the fourth region R 4 , which is another part of the outside of the side S 2 . The connecting conductor  25  is covered with the insulation cover  26  in the fourth region R 4  of the side S 2 . 
     On the third region R 3 , which is yet another part of the outside of the side S 2 , the RFID tag  3  is attached as being electrically insulated from the first signal conductor  22  and the second signal conductor  23 . As it will be described with reference to  FIG. 4 , a first electrode of the RFID tag  3 , which is attached to the packaging box  21 , is connected to the first signal conductor  22 . And, a second electrode of the RFID tag  3  is connected to the connecting conductor  27  or the second signal conductor  23 . 
     The packaging boxes  21  in the state illustrated in  FIG. 3  are piled up on the conductive pallet  16 , as illustrated in  FIG. 1 . The packaging boxes  21  are placed on the conductive pallet  16  in such a manner that the sides S of the adjoining packaging boxes  21  contact each other without spaces between the sides S. As a result, the sides S of the adjoining packaging boxes  21  are electrically connected to each other. 
     As described above, in at least six packaging boxes  21  of the upper layer piled up on the conductive pallet  16 , the first signal conductor  22  of one packaging box  21  has been electrically connected to the first signal conductor  22  of adjoining another packaging box  21 . Accordingly, the first signal conductors  22  of the six packaging boxes  21  of the upper layer have been electrically connected to each other. This is also applied to the six packaging boxes  21  of the lower layer. 
     In the two packaging boxes  21 , one of which is piled up on the other, the second signal conductor  23  on the top surface U of the packaging box  21  of the lower layer and the second signal conductor  23  on the base L of the packaging box  21  of the upper layer are electrically connected to each other. Accordingly, the two packaging boxes  21 , one of which is piled up on the other, are electrically connected. As a result, all the second signal conductors  23  which are piled up on the conductive pallet  16  are electrically connected via the conductive pallet  16  in the end. 
     In addition to the above, as illustrated in  FIG. 1 , the sides S of the adjoining packaging boxes  21  may be adhered to each other by an adhesive tape  41 , and the top surfaces U may be adhered to each other by an adhesive tape  42 . This can ensure the electrical connection between the piled up packaging boxes  21  more strongly. 
     Further, the adhesive tapes  41  and  42  may be a conductive tape. Conductive tapes  41  and  42  electrically connect the first signal conductors  22  provided on the sides S of the adjoining packaging boxes  21  to each other, and the second signal conductors  23  provided on the top surfaces U of the packaging boxes  21  of the upper layer to each other. In this case, the adhesive tape  41  adheres the sides S, which do not have the RFID tags  3  of the packaging boxes  21 , at one or more places. And, the adhesive tape  42  adheres the top surfaces U of the packaging boxes  21  in two different directions as illustrated in  FIG. 1 . As a result, when at least one of the RFID tags  3  faces the antenna  14 , the tag IDs of the twelve RFID tags  3  which are attached to the twelve packaging boxes  21  can be read out from the RFID tag  3  which faces the antenna  14 . 
       FIG. 4  illustrates the RFID tag  3  which is used in the tag ID reading method according to the embodiment. As illustrated in  FIG. 4 , the RFID tag  3  has a first electrode  33  and a second electrode  34 . The first electrode  33  is extended into a first direction, and its edge is connected to the first signal conductor  22 . The second electrode  34  is extended into a second direction, which is opposite to the first direction, and its edge is connected to the connecting conductor  27 . As a result, the second electrode  34  is connected to the second signal conductor  23 . 
     For this reason, the third region R 3  on the outside of the side S 2  is further divided into three. Specifically, as illustrated in  FIGS. 2 and 4 , the insulation region  28 , which is the region to which the RFID tag  3  is attached, is provided on a central part of the third region R 3 . The first signal conductor  22  and the connecting conductor  27  or the second signal conductor  23  are symmetrically provided at the both sides of the insulation region  28 . 
     As illustrated in  FIG. 4 , the first electrode  33  and the second electrode  34  of the RFID tag  3  are connected to a processing circuit  31  of the RFID tag  3 . To the processing circuit  31 , an antenna  32  is connected which surrounds a chip of the RFID tag  3 . 
       FIG. 5  illustrates mainly the RFID tags  3 , which are used in the tag ID reading method of the embodiment, and an embodiment of a circuit of the packaging box  21  including the RFID tags  3 . The processing circuit  31  of the RFID tag  3  includes a connection circuit  311 , a memory circuit  312 , a tag ID shared circuit  313 , and an antenna circuit  314 . 
     In the description below, the RFID tag  3  whose tag ID is 1 or ID=1 is sometimes referred to as an RFID tag  3 - 1 , for example. The packaging box  21  to which the RFID tag  3 - 1  is attached is sometimes referred to as a packaging box  21 - 1 , for example. The antenna circuit  314  and the like of the RFID tag  3 - 1  is sometimes referred to as an antenna circuit  314 - 1 , for example. These are also applied to the other RFID tags  3 , the other packaging boxes  21 , the other antenna circuits  314  and the like. 
     The connection circuit  311  is connected to the first signal conductor  22  and the second signal conductor  23  via the first electrode  33  and the second electrode  34 . One packaging box  21  is electrically connected to another packaging box  21  via the first signal conductor  22  and the second signal conductor  23 . Accordingly, a connection circuit  311  of an RFID tag  3  which is attached to one packaging box  21  is connected to another connection circuit  311  of another RFID tag  3  which is attached to another packaging box  21 . And, the tag IDs are transmitted and received between one RFID tag  3  and another RFID tag  3 . As a result, one connection circuit  311  receives one or more tag IDs from another connection circuit  311 , and transmits the tag IDs to another connection circuit  311 . One connection circuit  311  holds one or more tag IDs which are received from another RFID tag  3  for a predetermined period. 
     The memory circuit  312  holds the tag ID, which is allocated to the RFID tag  3  in advance. The tag ID is uniquely identified. The connection circuit  311  stores one or more tag IDs, which is received from another RFID tag  3 , in the memory circuit  312 . Thus, the tag IDs stored in the memory circuit  312  include the tag ID of another RFID tag  3  connected thereto via the first signal conductor  22  and the second signal conductor  23 . 
     The antenna circuit  314  includes the antenna  32 , and wirelessly transmits and receives information to and from the reader  13 . The tag ID shared circuit  313  sends out one or more tag IDs which is stored in the memory circuit  312  to the antenna circuit  314 , and causes the antenna circuit  314  to transmit the tag IDs to the reader  13 . 
     In general occasions, all the RFID tags  3  attached to all the packaging boxes  21  are electrically connected to each other, and can transmit and receive the information to and from each other. However, as illustrated in  FIG. 5 , there is a case that the packaging box  21 - 1 , which has the RFID tag  3  with the tag ID=1 or to which the RFID tag  3 - 1  is attached, is electrically connected to the another packaging box  21 - 2 , which has the RFID tag  3  with the tag ID=2, but is not electrically connected to another packaging box  21 - 3 , which has the RFID tag  3  with the tag ID=3. This case occurs, for example, when the first signal conductor  22  provided on the packaging box  21 - 3  becomes in a condition of non-contact with the first signal conductor  22  provided on the packaging box  21 - 2 . Incidentally, the second signal conductors  23  are in a condition of electrically connected to each other via the pallet  16 . The first signal conductors  22  and the second signal conductors  23  are used as transmission pass for a low voltage operating signal. Thus, a very small signal sent from the connection circuit  311  can be transmitted and received. 
       FIGS. 6 and 7  illustrate a process flowchart of a tag ID reading performed by the tag ID reading system of  FIG. 1 . 
     Before the reading of the tag ID is started, as illustrated in  FIG. 1 , the operator piles up the packaging boxes  21  on the conductive pallet  16  to make them the aggregate  20 . When the aggregate  20  is made, the tag IDs are read from a plurality of RFID tags  3  by the reader  13 . 
     In  FIG. 6 , when the personal computer  11  is inputted an instruction to start reading by the operator (step S 11 ), the personal computer  11  instructs the reader  13  via the HUB  12  to read the tag IDs from the RFID tags  3  (step S 12 ), and enters into the wait condition. Then, the personal computer  11  receives the tag IDs from the reader  13  as a response. In this manner, among the plurality of packaging boxes  21 , the RFID tags  3  of the packaging boxes  21 , which have the first electrode  33  and the second electrode  34  contact with each other, transmit and receive the tag IDs. The personal computer  11  stores the tag IDs, which are read by the reader  13  and received from the reader  13 , into the memory circuit  312  (step S 13 ). 
     In the storing processing at the step S 13 , the personal computer  11  discards tag IDs, which overlaps with tag IDs which has already been received, among the tag IDs received from the reader  13 . The personal computer  11  holds tag IDs, which do not overlap with tag IDs which has already been received or tag IDs which is received for the first time, among the tag IDs received from the reader  13 , in the memory from the start to the end of the reading. 
     Then, the personal computer  11  checks whether the reading of the RFID tags  3  has end or not (step S 14 ). The reading of the RFID tags  3  ends when the step S 12  is repeated for a predetermined number of times, for example eight times, by predetermined time interval, for example. Instead, the reading of the RFID tags  3  may end when all the tag IDs are stored in the memory. When the reading does not end, the processing at the step S 12  and subsequent steps are repeated. When the reading ends, the personal computer  11  displays the RFID tags  3  or the packaging boxes  21 , which corresponds to the tag IDs, on a display device, for example, as the source of the tag IDs (step S 15 ). 
     On the other hand, when the reader  13  is instructed to read the tag IDs from the personal computer  11  at the step S 12 , the reader  13  transmits radio waves for reading from the plurality of antennas  14  as a response to the instruction (step S 21 ), and enters into the wait condition. In response, the RFID tag  3  which can communicate with the reader  13  transmits one or more tag IDs including at least the tag ID of the RFID tag  3  to the reader  13 . For example, the RFID tag  3 - 1  transmits the tag ID=1 of the RFID tag  3 - 1  and the tag ID=2, which is obtained through the processing of  FIG. 7  to be described later, to the reader  13 . Then, whenever the reader  13  receives the tag IDs from the RFID tag  3  as a response, the reader  13  transmits the tag IDs which are read at that time to the personal computer  11  via the HUB  12  (step S 22 ). 
     For example, it is assumed that the RFID tags  3  whose IDs=1 to 3 are present. In this case, it is further assumed that the tag ID of ID=1 is received at the first reading, the tag IDs of ID=1 and ID=2 are received at each of the second to the fourth readings, the tag IDs of ID=1 to ID=3 are received at each of the fifth to the sixth readings, and the tag ID of ID=3 is received at each of the seventh to the eighth readings. 
     According to the above received result, the personal computer  11  stores the tag ID of ID=1 which is received at the first reading, the tag ID of ID=2 which is received at the second reading, and the tag ID of ID=3 which is received at the fifth reading. In contrast, the personal computer  11  discards the tag IDs of ID=1 which are received at the second to the sixth readings, since the tag IDs of ID=1 overlap with the tag ID which is received at the first reading. Similarly, the tag IDs of ID=2 which are received at the third to the sixth readings and the tag IDs of ID=3 which are received at the sixth to the eighth readings are also discarded as overlapping IDs. Consequently, the tag IDs of IDs=1 to 3 are obtained as a result of the readings. 
     In  FIG. 7 , the antenna circuit  314 - 1  of the RFID tag  3 - 1  whose tag ID is 1 receives the radio waves for reading from the reader  13  via the antenna  32 - 1  (step S 31 ). And, a tag ID shared circuit  313 - 1  generates a master declaration which indicates mastership in a multi-drop connection (step S 32 ). Then, the tag ID shared circuit  313 - 1  which generated the master declaration transmits the master declaration and a request for slave ID information to the other RFID tags  3  via the connection circuit  311 - 1  (step S 33 ), reads and holds the ID=1, which is the tag ID of the RFID tags  3 - 1 , from a memory circuit  312 - 1  (step S 34 ), and enters into the wait condition. 
     For example, as illustrated in  FIG. 5 , it is assumed that the packaging box  21 - 1  to which the RFID tag  3 - 1  is attached is electrically connected to the packaging box  21 - 2  to which an RFID tag  3 - 2  whose tag ID=2 is attached, but is not electrically connected to the packaging box  21 - 3  to which an RFID tag  3 - 3  whose tag ID=3 is attached. It is also assumed that the packaging box  21 - 1  to which the RFID tag  3 - 1  is attached and the packaging box  21 - 3  to which the RFID tag  3 - 3  is attached can receive the radio waves for reading from the reader  13 , but the packaging box  21 - 2  to which the RFID tag  3 - 2  is attached cannot receive the radio waves for reading from the reader  13 . 
     Then, in the RFID tag  3 - 1 , the connection circuit  311 - 1  receives the slave ID information or the tag ID=2 of the RFID tag  3 - 2  from the RFID tag  3 - 2  (step S 35 ). And, the tag ID shared circuit  313 - 1  holds the received tag ID (ID=2) (step S 36 ). Then, the tag ID shared circuit  313 - 1  transmits the held tag IDs (ID=1 to 2) to the reader  13  via the antenna circuit  314 - 1 , as a response to the radio waves for reading (step S 37 ). 
     As mentioned above, an antenna circuit  314 - 2  of the RFID tag  3 - 2  cannot receive the radio waves for reading from the reader  13 . Therefore, the antenna circuit  314 - 2  cannot receive the radio waves for reading at the step S 44 , and cannot generate the master declaration at the step S 45 , as indicated by dotted lines in  FIG. 7 . 
     In the state above described, the connection circuit  311 - 2  of the RFID tag  3 - 2  receives the master declaration and the request for slave ID information from the RFID tag  3 - 1  (step S 41 ). In response, a tag ID shared circuit  313 - 2  of the RFID tag  3 - 2  reads the tag ID (ID=2) of the RFID tag  3 - 2  from a memory circuit  312 - 2 . And, the tag ID shared circuit  313 - 2  delays the returning processing by Δt (step S 42 ), and then returns the read out the tag ID to the RFID tag  3 - 1  via a connection circuit  311 - 2 , as a response to the request or as a slave ID information (step S 43 ). 
     The Δt is a delay time, and defined by using a random number. For this purpose, the tag ID shared circuit  313  includes a random number generating circuit. Due to the delay time responses from a plurality of RFID tag  3  do not clash at the same time. 
     After the above processing, the RFID tag  3 - 2  is into a state in which the RFID tag  3 - 2  can receive the radio waves for reading from the reader  13 . Then, the RFID tag  3 - 2  may receive the radio waves for reading (step S 44 ), and may transmit a master declaration (step S 45 ). However, the RFID tag  3 - 1  already transmitted the master declaration. Thus, the RFID tags  3  other than the RFID tag  3 - 2 , which received the master declaration from the RFID tag  3 - 1 , ignore the master declaration from the RFID tag  3 - 2 . 
     On the other hand, in the same way with the steps S 31  to S 34 , the RFID tag  3 - 3  receives the radio waves for reading from the reader  13  (step S 51 ), generates a master declaration (step S 52 ), transmits the master declaration and a request for slave ID information to the other RFID tags  3  (step S 53 ), reads and holds the tag ID (ID=3) of the RFID tag  3 - 3  (step S 54 ), and enters into the wait condition. 
     However, the RFID tag  3 - 3  is electrically connected to none of the other RFID tags  3 . Thus, a connection circuit  311 - 3  does not receive slave ID information from any of the RFID tags  3  (step S 55 ). Accordingly, a tag ID shared circuit  313 - 3  does not hold the tag IDs of the other RFID tags  3  (step S 56 ), and transmits only the ID=3, which is the tag ID of the RFID tag  3 - 3  which has been held, to the reader  13  via an antenna circuit  314 - 3 , as a response to the radio waves for reading (step S 57 ). 
       FIG. 8  illustrates another embodiment of the process flowchart of a tag ID reading performed by the tag ID reading system of  FIG. 1 . In this embodiment, the personal computer  11  performs the same processing with the steps S 11  to S 15  illustrated in  FIG. 6 , and the reader  13  performs the same processing with the steps S 21  to S 22  illustrated in  FIG. 6 . In response to the processing, the RFID tag  3  performs the processing illustrated in  FIG. 8  instead of that of  FIG. 7 . The connection state among the RFID tags  3  from the RFID tag  3 - 1  whose tag ID=1 to the RFID tag  3 - 3  whose tag ID=3 and whether they can receive the radio waves for reading or not are assumed as the same as those in the case of  FIG. 7 . 
     In  FIG. 8 , the antenna circuit  314 - 1  of the RFID tag  3 - 1  receives the radio waves for reading from the reader  13  in the same way with the step S 31  (step S 61 ). And, the tag ID shared circuit  313 - 1  transmits a request for ID information to the other RFID tags  3  in the same way with the step S 33  (step S 62 ). 
     Then, the connection circuit  311 - 1  receives the ID information or the tag ID=2 of another RFID tag  3 - 2  from the RFID tag  3 - 2  in the same way with the step S 35 . When the connection circuit  311 - 1  of the RFID tag  3 - 1  receives the request for ID information from another RFID tag  3 , the tag ID shared circuit  313 - 1  reads the tag ID of the RFID tag  3 - 1  from the memory circuit  312 - 1 , and returns the tag ID of the RFID tag  3 - 1  to another RFID tag  3  in the same way with the step S 71 , which will be described later (step S 63 ). After the above processing, the tag ID shared circuit  313 - 1  holds the tag ID (ID=2) received from the RFID tag  3 - 2  in the same way with the step S 36  (step S 64 ), reads and holds the tag ID (ID=1) of the RFID tag  3 - 1  from the memory circuit  312 - 1  in the same way with the step S 34  (step S 65 ), and transmits the held tag IDs (ID=1 to 2) to the reader  13  in the same way with the step S 37  (step S 66 ). 
     The antenna circuit  314 - 2  of the RFID tag  3 - 2  cannot receive the radio waves for reading from the reader  13 . Therefore, the antenna circuit  314 - 2  cannot receive the radio waves for reading from the reader  13  at the step S 75 , and cannot generate the master declaration at the step S 76 . 
     In the state described above, the connection circuit  311 - 2  of the RFID tag  3 - 2  receives the request for ID information from the RFID tag  3 - 1 . Then, the tag ID shared circuit  313 - 2  reads the tag ID (ID=2) of the RFID tag  3 - 2  from the memory circuit  312 - 2 , delays the returning processing by Δt in the same way with the step S 42 , and then returns the tag ID (ID=2) to the RFID tag  3 - 1  via the connection circuit  311 - 2 , as a response (ID information) to the request (step S 71 ). 
     After the above processing, there is a possibility that the RFID tag  3 - 2  receives the tag ID from another RFID tag  3 . In this case, the tag ID shared circuit  313 - 2  holds the tag ID received from the RFID tag  3  (step S 72 ), reads and holds the tag ID (ID=2) of the RFID tag  3 - 2  from the memory circuit  312 - 2  (step S 73 ), and transmits the held tag IDs to the reader  13  (step S 74 ), in the same way with the steps S 64  to S 66 . 
     After the above processing, when the RFID tag  3 - 2  becomes into a state that the RFID tag  3 - 2  can receive the radio waves for reading from the reader  13 , the RFID tag  3 - 2  may receive the radio waves for reading (step S 75 ), and may transmit the request for ID information (step S 76 ). However, the RFID tag  3 - 1  already transmitted the request for ID information. Thus, the RFID tags  3  other than the RFID tag  3 - 2  ignore the request for ID information from the RFID tag  3 - 2 . 
     Further, still another RFID tag  3 - 3  performs the steps S 81  to S 86  in the same way with the steps S 61  to S 66 . However, the RFID tag  3 - 3  is connected to none of the RFID tags  3 . Therefore, the connection circuit  311 - 3  does not receive ID information from any of the RFID tags  3  (step S 83 ). The tag ID shared circuit  313 - 3  does not hold the tag IDs of the other RFID tags  3  (step S 84 ), and transmits only the tag ID of the RFID tag  3 - 3  which is held to the reader  13  via the antenna circuit  314 - 3  as a response to the radio waves for reading (step S 86 ). 
       FIG. 9  illustrates another embodiment of the tag ID reading method and another embodiment of the packaging boxes used for the method. 
     The embodiment of  FIG. 9  uses the packaging box  21  having the structure illustrated in  FIGS. 2 and 3  as a small box (or an inner box)  21 B. In this embodiment, a plurality of small boxes  21 B, two small boxes  21 B for example, are put into a big box (or an outer box)  21 B′. The embodiment of  FIG. 9  can be applied to a product including two parts, for example. 
     In this case, there is a possibility that the reader  13  cannot directly read the tag ID of the RFID tag  3 , which is attached to the small box  21 B contained in the outer box  21 B′. Then, as the big box  21 B′, a packaging box is used which has a structure similar to the packaging box  21  of  FIGS. 2 and 3 . 
     The big box  21 B′ has the structure illustrated in  FIGS. 2 and 3  on its outside, and has the structure illustrated in  FIGS. 2 and 3  on its inside to which the RFID tag  3  is not attached. Thus, the big box  21 B′ has the completely same structure on the outside and the inside except that the RFID tag  3  is not attached to the inside. In other words, a relation between the outside of the big box  21 B′ and the inside of the big box  21 B′ is a mirror. With that structure, the first signal conductors  22  and the second signal conductors  23  which are provided on the outside and the inside of the big box  21 B′ are electrically connected to each other. Although they are not illustrated in the drawing, the connection is accomplished by a conductive tape, a metal fastening or the like. 
     By using the above structure, when the small boxes  21 B are contained in the big box  21 B′, the sides of the small boxes  21 B and the big box  21 B′ contact with each other, and thus, their first signal conductors  22  are electrically connected to each other. And, the top surfaces and the bases of the small boxes  21 B and the big box  21 B′ contact with each other, and thus, their second signal conductors  23  are electrically connected to each other. 
     As a result, as illustrated in  FIG. 9 , when a plurality of big boxes  21 B′, four big boxes  21 B′ in the embodiment of  FIG. 9 , are piled up, the tag IDs of the RFID tags  3  of the small boxes  21 B can be read in the same way with the case of  FIG. 1  in which the packaging boxes  21  are piled up. In this embodiment, it is not necessary to take the small boxes  21 B out from the big boxes  21 B′ after the small boxes  21 B are once packed in the big box  21 B′. Accordingly, it is quite convenient. 
       FIG. 10  illustrates a yet another embodiment of the tag ID reading method and a yet another embodiment of the packaging box used for the method.  FIG. 11  illustrates a development of a packaging material which is to form the packaging box of  FIG. 10 . 
     In this embodiment, instead of the packaging box  21  having the structure illustrated in  FIGS. 2 and 3 , a packaging box  21 C and a packaging material  21 C′ are used which have a structure much simpler than that of the packaging box  21 . Specifically, in the packaging box  21 C, two signal conductors  22  and  23 , which connect the two electrodes  33  and  34  of the RFID tag  3 , are provided in each of two parts of the packaging box  21 C. The two parts are formed by dividing the packaging box  21 C into two in a horizontal direction, respectively, in a case that the packaging box  21 C is placed with the base L downside. In other words, as illustrated in  FIGS. 10 and 11 , the signal conductor  22  is provided on one of the two parts of the packaging box  21 C, for example, the left side region. And, the signal conductor  23  is provided on the other of the two parts, for example, the right side region. The division makes it possible to omit the fourth region R 4 , which is provided on each of the packaging boxes  21  illustrated in  FIGS. 2 and 3 , and which connects the second signal conductors  23 . 
     In the embodiments of  FIGS. 10 and 11 , an insulation region  24  (the fifth region R 5 ), which insulates the signal conductor  22  from the signal conductor  23 , is provided in the vertical direction along with a center line of the packaging box  21 C in a case that the packaging box  21 C is placed with the base L downside. The fifth region R 5  is provided on a boundary between the signal conductors  22  and  23 , which are provided on the left side and the right side of the packaging box  21 C, respectively. As a result, the packaging box  21 C is divided into two, the left side and the right side. The third region R 3 , for which the RFID tag  3  is attached, is provided on and across the fifth region R 5 . The insulation region  28 , for which the RFID tag  3  is attached, is provided in integrated form with the insulation region  24 . And, the connecting conductor  27  which is provided on the packaging box  21  of  FIGS. 2 and 3  is omitted. 
     As described above, the packaging box  21 C with a simpler structure is obtained by omitting the fourth region R 4 . And, the packaging box  21 C does not need the conductive pallet  16  of  FIG. 1 . That is, a pallet  16 B of  FIG. 10  needs not be conductive. The packaging box  21 C can also omit the attachment of the conductive tape in the vertical direction illustrated in  FIG. 1 . 
     The packaging boxes  21 C need to be in the same size. The packaging boxes  21 C need to be placed in such a manner that polarities of the sides are matched which contact with each other. 
       FIG. 12  illustrates a yet another embodiment of the tag ID reading method and a yet another embodiment of the packaging box used for the method.  FIG. 13  illustrates a development of a packaging material which is to form the packaging box of  FIG. 12 . 
     In this embodiment, instead of the packaging box  21  having the structure illustrated in  FIGS. 2 and 3 , a packaging box  21 D and a packaging material  21 D′ which have a structure including power feeding means for the RFID tag  3  are used. Specifically, in the packaging box  21 D, the two signal conductors  22  and  23  and two power feeding conductors  291  and  292  are provided on each of four parts of the packaging box  21 D. The four parts are formed by dividing the packaging box  21 D into four in the horizontal direction, respectively, in a case that the packaging box  21 D is placed with the base L downside. In other words, as illustrated in  FIGS. 12 and 13 , the packaging box  21 D is provided with the power feeding conductor  291  (+), the signal conductor  23 , the signal conductor  22 , and the power feeding conductor  292  (−) from the left in the drawings. The RFID tag  3  attached to the packaging box  21 D is connected to the power feeding conductor  291  and the power feeding conductor  292 . As a result, the RFID tag  3  is supplied with the power. 
     The insulation regions  24  (the fifth region R 5 ) for insulating the signal conductor  22  from the signal conductor  23  are provided in the vertical direction along with a center line of the packaging box  21 D in a case that the packaging box  21 D is placed with the base L downside. The fifth regions R 5  are provided on the boundaries between the signal conductors  22  and  23  provided on the left side and the right side of the packaging box  21 D, respectively. The insulation regions  24 ′, which insulates the two power feeding conductors  291  and  292  from the signal conductors  22  and  23 , are provided on the packaging box  21 D in the above vertical direction. The third region R 3 , for which the RFID tag  3  is attached, is provided on and across the regions  24  and  24 ′. The insulation region  28 , for which the RFID tag  3  is attached, is provided in integrated form with the insulation region  24 . And, the connecting conductor  27  is omitted. 
     As described above, the power is supplied to the RFID tag  3  of the packaging box  21 D, which cannot receive the radio waves from the reader  13  as the radio waves is blocked. This makes it possible that the tag ID is read even from the packaging box  21 D which cannot receive the radio waves. 
     The packaging boxes  21 D need to be in the same size. The packaging boxes  21 D need to be placed in such a manner that polarities of the sides are matched which contact with each other.