Abstract:
An RFID tag has an IC chip and an antenna connected to the IC chip, the RFID tag including: a spacer that has elasticity; a first locking section that is formed around the IC chip; a second locking section that is arranged in a position apart from the first locking section across the spacer, is displaced toward the first locking section and locked on the first locking section by pressing force with which the spacer is pressed, and applies reactive force against the pressing force around the IC chip via the first locking section when the pressing force is removed; and a destruction section that destroys the IC chip or the antenna with the reactive force from the second locking section.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-040269, filed on Feb. 24, 2009, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present invention relates to a radio frequency identification (RFID) tag which has an IC chip and an antenna connected to the integrated circuit (IC) chip. 
     BACKGROUND 
     In order to prevent the unauthorized use of RFID tag, technologies are known in which an RFID tag, once attached to an intended article, is destroyed by the removal of only an upper part of the RFID tag.
     [Patent Document 1] Japanese Laid-Open Patent Publication No. 2000-48147   [Patent Document 2] Japanese Laid-Open Patent Publication No. 2005-242971   [Patent Document 3] Japanese Patent No. 3,636,202   

     The foregoing RFID tag for preventing unauthorized use needs to be bonded to an intended article. The RFID tag is therefore not applicable to one that is not bonded to the intended articles. Moreover, the RFID tag for preventing unauthorized use becomes ineffective if the RFID tag is taken off from the intended article. 
     SUMMARY 
     According to an aspect of the invention, an RFID tag has an IC chip and an antenna connected to the IC chip, the RFID tag including: a spacer that has elasticity; a first locking section that is formed around the IC chip; a second locking section that is arranged in a position apart from the first locking section across the spacer, is displaced toward the first locking section and locked on the first locking section by pressing force with which the spacer is pressed, and applies reactive force against the pressing force around the IC chip via the first locking section when the pressing force is removed; and a destruction section that destroys the IC chip or the antenna with the reactive force from the second locking section. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a bottom view illustrating an example of the configuration of an RFID tag  1   a;    
         FIG. 2  is a front view illustrating the example of the configuration of the RFID tag  1   a;    
         FIG. 3  is a top view illustrating an example of the state of attachment of the RFID tag  1   a;    
         FIG. 4  is a front view illustrating the example of the state of attachment of the RFID tag  1   a;    
         FIG. 5  is a sectional view illustrating an example of the configuration of the RFID tag  1   a  as seen from the front; 
         FIG. 6  is a front view illustrating an example of the configuration of destruction mechanisms  13   a  and  14 ; 
         FIG. 7  is a bottom view illustrating an example of the configuration in the vicinity of the destruction mechanism  13   a;    
         FIG. 8  is a side view illustrating the example of the configuration in the vicinity of the destruction mechanism  13   a;    
         FIG. 9  is a sectional view illustrating an example of a first state of the RFID tag  1   a  as seen from the front; 
         FIG. 10  is a sectional view illustrating an example of a second state of the RFID tag  1   a  as seen from the front; 
         FIG. 11  is a sectional view illustrating an example of a third state of the RFID tag  1   a  as seen from the front; 
         FIG. 12  is a bottom view illustrating an example of a first step in the method of manufacturing the RFID tag  1   a;    
         FIG. 13  is a side view illustrating the example of the first step in the method of manufacturing the RFID tag  1   a;    
         FIG. 14  is a bottom view illustrating an example of a second step in the method of manufacturing the RFID tag  1   a;    
         FIG. 15  is a side view illustrating the example of the second step in the method of manufacturing the RFID tag  1   a;    
         FIG. 16  is a bottom view illustrating an example of a third step in the method of manufacturing the RFID tag  1   a;    
         FIG. 17  is a side view illustrating the example of the third step in the method of manufacturing the RFID tag  1   a;    
         FIG. 18  is a bottom view illustrating an example of a fourth step in the method of manufacturing the RFID tag  1   a;    
         FIG. 19  is a side view illustrating the example of the fourth step in the method of manufacturing the RFID tag  1   a;    
         FIG. 20  is a sectional view illustrating an example of a fifth step in the method of manufacturing the RFID tag  1   a;    
         FIG. 21  is a sectional view illustrating an example of the RFID tag  1   a  with malfunction preventive measures as seen from the front; 
         FIG. 22  is a bottom view illustrating an example of the configuration of an RFID tag  1   b;    
         FIG. 23  is a bottom view illustrating an example of the configuration of an inlet substrate  12   b;    
         FIG. 24  is a sectional view illustrating an example of the third state of the RFID tag  1   c  as seen from the front; 
         FIG. 25  is a front view illustrating an example of the configuration of a destruction mechanism  13   b;    
         FIG. 26  is a perspective view illustrating an example of the configuration of the destruction mechanism  13   b  and the inlet substrate  12   a;    
         FIG. 27  is a sectional view illustrating an example of the second state of an RFID tag  1   d  as seen from the front; 
         FIG. 28  is a front view illustrating an example of the configuration of a destruction mechanism  13   c ; and 
         FIG. 29  is a sectional view illustrating an example of the third state of the RFID tag  1   d  as seen from the front. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the drawings. 
     Embodiment 1 
     The configuration of an RFID tag  1   a  according to the present embodiment will be described below. 
       FIG. 1  is a bottom view illustrating an example of the configuration of the RFID tag  1   a .  FIG. 2  is a front view illustrating the example of the configuration of the RFID tag  1   a . The RFID tag  1   a  of the present embodiment includes an attaching band  2 , a circuit accommodating section  3 , and spacers  6 . The attaching band  2  has two ends that can be connected to each other, with the same function as that of a cable tie. The circuit accommodating section  3  has walls which constitute a spacer  7 . 
       FIG. 3  is a top view illustrating an example of the state of attachment of the RFID tag  1   a .  FIG. 4  is a front view illustrating the example of the state of attachment of the RFID tag  1   a . The RFID tag  1   a  is attached to an object of attachment  5 . Here, the attaching band  2  is wound around and fastened to the object of attachment  5 , whereby the circuit accommodating section  3  and the spacers  6  are compressed. 
       FIG. 5  is a sectional view illustrating an example of the configuration of the RFID tag  1   a  as seen from the front. The diagram depicts the interior of the circuit accommodating section  3  of the RFID tag  1   a . The circuit accommodating section  3  includes a chip  11  (IC chip), an inlet substrate  12   a , destruction mechanisms  13   a  and  14 , the spacer  7 , and adhesive agents  16   a  and  16   b . Of the wall surfaces of the spacer  7 , the upper wall surface in contact with the inlet substrate  12   a  will be referred to as a top wall, the lower wall surface to be bonded to the destruction mechanism  14  as a bottom wall, and the remaining wall surfaces as side walls. The spacers  6  and  7  are made of an elastic body such as rubber. The spacers  6  and  7  may be coil springs or flat springs. 
     The area of the inlet substrate  12   a  in contact with the destruction mechanism  13   a  will be referred to as a center portion (first location). The areas to be bonded to the attaching band  2  will be referred to as end portions (second location). The top surface of the chip  11  is bonded to the bottom surface of the center portion of the inlet substrate  12   a . The chip  11  has electrodes which are connected to an antenna pattern on the inlet substrate  12   a . The bottom surfaces of both end portions of the inlet substrate  12   a  are bonded to the top surface of the top wall of the spacer  7  by the adhesive agent  16   b . The top surfaces of both end portions of the inlet substrate  12   a  are bonded to the bottom surface of the attaching band  2  by the adhesive agent  16   a.    
       FIG. 6  is a front view illustrating an example of the configuration of the destruction mechanisms  13   a  and  14 . In the diagram, the upper member represents the destruction mechanism  13   a , and the lower the destruction mechanism  14 . 
     The destruction mechanism  13   a  has a base  21  and hooks  22 . The base  21  and the hooks  22  are joined to each other. The base  21  is fixed to the top surface of the center portion of the inlet substrate  12   a . The hooks  22  are extended through the inlet substrate  12   a  into the internal space of the spacer  7 . The destruction mechanism  13   a  is not joined to the attaching band  2 . 
     The destruction mechanism  14  has a base  23  and hooks  24 . The base  23  and the hooks  24  are joined to each other. The base  23  is fixed to the bottom surface of the bottom wall of the spacer  7 . The hooks  24  are extended through the bottom wall of the spacer  7  into the internal space of the spacer  7 . 
     The hooks  22  have hook holes  25  for the protrusions of the hooks  24  to catch in. 
       FIG. 7  is a bottom view illustrating an example of the configuration in the vicinity of the destruction mechanism  13   a . The diagram depicts the attaching band  2 , the destruction mechanism  13   a , the inlet substrate  12   a , and the chip  11  of the RFID tag  1   a .  FIG. 8  is a side view illustrating the example of the configuration in the vicinity of the destruction mechanism  13   a . This diagram is a side view taken from the right of  FIG. 7 . The left of the diagram corresponds to below the inlet substrate  12   a . The inlet substrate  12   a  has an antenna pattern  17  (antenna). 
     Hereinafter, description will be given of a change in the state of the RFID tag  1   a  when attached. 
       FIG. 9  is a sectional view illustrating an example of a first state of the RFID tag  1   a  as seen from the front. The first state refers to where the RFID tag  1   a  is yet to be attached to the object of attachment  5 , and the bottom surface of the bottom wall of the spacer  7  is in contact with the object of attachment  5 . 
       FIG. 10  is a sectional view illustrating an example of a second state of the RFID tag  1   a  as seen from the front. The second state is where the attaching band  2  is fastened by an operator so that the RFID tag  1   a  is attached to the object of attachment  5 . When fastened, the attaching band  2  is pressed against the object of attachment  5 , so that the RFID tag  1   a  undergoes pressing force F 1  that presses the base  21  toward the base  23  as well as the base  23  toward the base  21 . The pressing force F 1  compresses the spacer  7  for elastic deformation, whereby the hooks  22  and the hooks  24  are locked on each other. 
     Hereinafter, description will be given of a change in the state of the RFID tag  1   a  when detached. 
       FIG. 11  is a sectional view illustrating an example of a third state of the RFID tag  1   a  as seen from the front. The third state is where the RFID tag  1   a  attached is detached from the object of attachment  5 . The spacer  7  produces elastic restoring force (reactive force) F 2  against the pressing force F 1 . 
     When the attaching band  2  is cut or otherwise loosened and the fastening force of the attaching band  2  decreases to reduce the pressing force F 1 , the RFID tag  1   a  is subjected to the elastic restoring force F 2  which presses both end portions of the inlet substrate  12   a  upward and the base  23  downward. In the meantime, the distance between the center portion of the inlet substrate  12   a  and the base  23  is maintained because the bases  21  and  23  are constrained with the hooks  22  and  24  locked on each other. As a result, the center portion and both end portions of the inlet substrate  12   a  undergo the forces in the opposite directions, which destroy the inlet substrate  12   a  and the antenna pattern  17 . 
     The elastic restoring force F 2  exceeds the strength of the inlet substrate  12   a.    
     Since the destruction mechanisms  13   a  and  14  are covered with the spacer  7 , an operator who detaches the RFID tag  1   a  from the object of attachment  5  in an unauthorized fashion is not able to learn of the destruction mechanisms  13   a  and  14  from the appearance. 
     Description will now be given of the method of manufacturing the RFID tag  1   a.    
       FIG. 12  is a bottom view illustrating an example of a first step in the method of manufacturing the RFID tag  1   a .  FIG. 13  is a side view illustrating the example of the first step in the method of manufacturing the RFID tag  1   a . In the first step, holes  31 ,  32 ,  33 , and  34  are formed through the center portion of the inlet substrate  12   a . The chip  11  is mounted on the bottom surface of the center portion of the inlet substrate  12   a.    
       FIG. 14  is a bottom view illustrating an example of a second step in the method of manufacturing the RFID tag  1   a .  FIG. 15  is a side view illustrating the example of the second step in the method of manufacturing the RFID tag  1   a . The base  21  is arranged on the top surface of the center portion of the inlet substrate  12   a.    
       FIG. 16  is a bottom view illustrating an example of a third step in the method of manufacturing the RFID tag  1   a .  FIG. 17  is a side view illustrating the example of the third step in the method of manufacturing the RFID tag  1   a . The hooks  22  are arranged on the bottom surface of the center portion of the inlet substrate  12   a . The base  21  and the hooks  22  are joined to each other. 
       FIG. 18  is a bottom view illustrating an example of a fourth step in the method of manufacturing the RFID tag  1   a .  FIG. 19  is a side view illustrating the example of the fourth step in the method of manufacturing the RFID tag  1   a . The attaching band  2  is arranged on the top surface of the inlet substrate  12   a . The top surfaces of both end portions of the inlet substrate  12   a  are bonded to the bottom surface of the attaching band  2  by the adhesive agent  16   a . The base  21  and the attaching band  2  are not bonded to each other. 
       FIG. 20  is a sectional view illustrating an example of a fifth step in the method of manufacturing the RFID tag  1   a . The spacer  7  with the destruction mechanism  14  on its bottom wall is arranged on the bottom surface of the inlet substrate  12   a . The bottom surfaces of both end portions of the inlet substrate  12   a  are bonded to the top surface of the top wall of the spacer  7  by the adhesive agent  16   b.    
     According to the present embodiment, the inlet substrate  12   a  is destroyed when the RFID tag  1   a  attached to the object of attachment  5  is detached. This makes it possible to prevent the unauthorized use of the RFID tag  1   a.    
     Measures for preventing malfunction of the RFID tag  1   a  will be described below. 
       FIG. 21  is a sectional view illustrating an example of the RFID tag  1   a  with malfunction preventive measures as seen from the front. A stopper  26  is put on the hooks  22  to stop the hook holes  25  after manufacturing until attachment so that the hooks  22  and  24  will not lock into each other due to a shock or impact during shipment. The stopper  26  is removed immediately before attachment. 
     Alternatively, the stopper  26  may be put on the hooks  24 . The stoppers  26  may be put on both the hooks  22  and  24 . 
     Embodiment 2 
     Hereinafter, description will be given of the configuration of an RFID tag  1   b  according to the present embodiment. 
       FIG. 22  is a bottom view illustrating an example of the configuration of the RFID tag  1   b . The components of the RFID tag  1   b  identical or equivalent to those of the RFID tag  1   a  will be designated by the same reference numerals as those of the RFID tag  1   a . Description thereof will be omitted here. As compared to the RFID tag  1   a , the RFID tag  1   b  has an inlet substrate  12   b  instead of the inlet substrate  12   a.    
       FIG. 23  is a bottom view illustrating an example of the configuration of the inlet substrate  12   b . As compared to the inlet substrate  12   a , the inlet substrate  12   b  has four notches (grooves)  41  at the borders between the center portion and both end portions. The notches  41  are intended to lower the strength of the borders. When the RFID tag  1   b  reaches the third state through the first and second states as in Embodiment 1, the notches  41  increase the certainty of destruction of the inlet substrate  12   b . The notches  41  are formed in the long sides of the plane of the inlet substrate  12   b  so as to extend in the direction of the borders. 
     Alternatively, grooves may be formed in the surface of the inlet substrate along the borders so that the grooves ensure the destruction. The grooves may be formed in either of the top and bottom surfaces. The notches  41  in the long sides of the plane of the inlet substrate and the grooves in the surface of the inlet substrate may be used in combination. 
     According to the present embodiment, the inlet substrate  12   b  is destroyed with higher reliability when the RFID tag  1   b  attached to the object of attachment  5  is detached. 
     Embodiment 3 
     Now, description will be given of the configuration of an RFID tag  1   c  according to the present embodiment. 
       FIG. 24  is a sectional view illustrating an example of the third state of the RFID tag  1   c  as seen from the front. The diagram depicts the third state that is reached through the first and second states as in Embodiment 1, i.e., where the RFID tag  1   c  is detached from the object of attachment  5 . The components of the RFID tag  1   c  identical or equivalent to those of the RFID tag  1   a  will be designated by the same reference numerals as those of the RFID tag  1   a . Description thereof will be omitted here. As compared to the RFID tag  1   a , the RFID tag  1   c  has a destruction mechanism  13   b  instead of the destruction mechanism  13   a.    
       FIG. 25  is a front view illustrating an example of the configuration of the destruction mechanism  13   b . The components of the destruction mechanism  13   b  identical or equivalent to those of the destruction mechanism  13   a  will be designated by the same reference numerals as those of the destruction mechanism  13   a . Description thereof will be omitted here. As compared to the destruction mechanism  13   a , the destruction mechanism  13   b  has wires  42  instead of the hooks  22 . 
       FIG. 26  is a perspective view illustrating an example of the configuration of the destruction mechanism  13   b  and the inlet substrate  12   a . The point of view in the diagram is located at the bottom side of the inlet substrate  12   a . When the RFID tag  1   c  is attached, the wires  42  are caught on the hooks  24  as if the hooks  22  are in the second state of Embodiment 1. The bases  21  and  23  are thereby constrained so that the distance between the bases  21  and  23  does not exceed a predetermined distance. When the RFID tag  1   c  is detached, the center portion and both end portions of the inlet substrates  12   a  undergo forces in the respective opposite directions as in the third state of Embodiment 1. The inlet substrate  12   a  is thus destroyed. 
     Embodiment 4 
     Now, description will be given of the configuration of an RFID tag  1   d  according to the present embodiment. 
       FIG. 27  is a sectional view illustrating an example of the second state of the RFID tag  1   d  as seen from the front. The diagram depicts the same second state as in Embodiment 1, i.e., where the RFID tag  1   d  is attached to the object of attachment  5 . The components of the RFID tag  1   d  identical or equivalent to those of the RFID tag  1   a  will be designated by the same reference numerals as those of the RFID tag  1   a . Description thereof will be omitted here. As compared to the RFID tag  1   a , the RFID tag  1   d  has a destruction mechanism  13   c  instead of the destruction mechanism  13   a.    
       FIG. 28  is a front view illustrating an example of the configuration of the destruction mechanism  13   c . The components of the destruction mechanism  13   c  identical or equivalent to those of the destruction mechanism  13   a  will be designated by the same reference numerals as those of the destruction mechanism  13   a . Description thereof will be omitted here. As compared to the destruction mechanism  13   a , the destruction mechanism  13   c  has an additional protrusion  43  on the bottom surface of the base  21 . The protrusion  43  is positioned so as to be opposed to the center portion of the chip  11  across the inlet substrate  12   a . The top of the protrusion  43  is directed toward the inlet substrate  12   a.    
       FIG. 29  is a sectional view illustrating an example of the third state of the RFID tag  1   d  as seen from the front. The diagram depicts the same third state as in Embodiment 1, i.e., where the RFID tag  1   d  is detached from the object of attachment  5 . 
     When the attaching band  2  is loosened to reduce the pressing force F 1  as in the third state of Embodiment 1, the elastic restoring force F 2  from the spacer  7 , which presses both end portions of the inlet substrate  12   a  upward and the base  23  downward, exceeds the pressing force F 1 . In the meantime, the distance between the protrusion  43  and the base  23  is maintained because the bases  21  and  23  are constrained with the hooks  22  and  24  fastened to each other. Consequently, the protrusion  43  and the inlet substrate  12   a  undergo forces in the opposite directions, so that the top of the protrusion  43  sticks into the inlet substrate  12   a  to destroy the chip  11  and the inlet substrate  12   a.    
     According to the present embodiment, the chip  11  and the inlet substrate  12   a  are destroyed when the RFID tag  1   d  attached to the object of attachment  5  is detached. This makes it possible to prevent the unauthorized use of the RFID tag  1   d  and the chip  11 . 
     The first locking section corresponds to the hooks  22  or the wires  42 . The second locking section corresponds to the destruction mechanism  14 . The destruction section corresponds to the base  21  or the protrusion  43 . The support section corresponds to the inlet substrate  12   a  or the inlet substrate  12   b.    
     Once attached to an object of attachment, the RFID tags disclosed in the foregoing respective embodiments are destroyed when detached from the object of attachment. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a depicting of the superiority and inferiority of the invention. Although the embodiment(s) of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.