Patent Publication Number: US-2007097003-A1

Title: Antenna device, antenna noncontact data transmitter and receiver, communicator sheet, communicator loop, and antenna sheet

Description:
BACKGROUND  
      1. Field of the Invention  
      The present invention relates to an antenna of a RFID communicator (such as a noncontact data transmitter and receiver).  
      2. Description of the Related Art  
      In recent years, attention has been drawn to RFID (Radio Frequency Identification) as a system for inventory control, etc. in the introduction of IT and automation to the society. A noncontact data transmitter and receiver using RFID includes an antenna and an IC chip that performs data processing and other functions.  
      Such a noncontact data transmitter and receiver communicates with external devices through radio waves or electromagnetic waves. For example, when receiving radio waves (including a control signal) generated from an external device, the noncontact data transmitter and receiver generates (induced) electromotive force through the operation of the antenna (the antenna of the noncontact data transmitter and receiver). Using the electromotive force, the IC chip performs data processing in accordance with the control signal, and the processing result is transmitted through radio waves from the antenna. The external device receives and reads the processing result.  
      Such a noncontact data transmitter and receiver is expected to have more functions added in the future, and a high-performance antenna is essential in the noncontact data transmitter and receiver. In this trend, there is an increasing demand for antennas that can efficiently receive radio waves from various directions. Such built-in antennas are disclosed in Japanese Patent Application Laid-Open Nos. 2001-156526 (publication date: Jun. 8, 2001), 2004-260586 (publication date: Sep. 16, 2004), and 2000-339069 (publication date: Jun. 6, 2000).  
      However, the two-dimensional antenna disclosed in Japanese Patent Application Laid-Open No. 2001-156526 needs to change orientations in accordance with the direction of radio waves, which causes inconvenience. Also, three-dimensional antennas that can receive radio waves from various directions shown in  FIGS. 15A and 15B  have been suggested. For example, with radio waves being generated from three directions, three conductor loops (X, Y, Z) are formed, and are connected in parallel with one another (see  FIG. 15A ) or connected in series (see  FIG. 15B ). However, as the shapes of the antennas are complicated, the production costs are large. As shown in  FIGS. 15A and 15B , the load on the entire antenna is equivalent to the load of  12  sides (the total number of sides of X, Y, and Z), with the conductor for each direction (each conductor loop) having four sides. As a result, large power loss is caused (or the amount of power that can be consumed at a circuit such as an IC chip becomes small).  
     SUMMARY  
      Embodiments of the present invention provide antennas (such as antennas for noncontact data transmitters and receivers) that can receive radio waves from various directions with efficiency.  
      In accordance with one aspect of the present invention, an antenna device comprises: a holding material; and first through third conductor units that are provided on the holding material; wherein the holding material has first through third planes that share one corner and are perpendicular to one another, the first conductor unit is placed along the first plane, the second conductor unit is placed along the second plane, and the third conductor unit is placed along the third plane.  
      In accordance with one aspect of the present invention, an antenna device comprises: a first conductor unit: a second conductor unit that is electrically connected to the first conductor unit; a third conductor unit that is electrically connected to the first conductor unit and the second conductor unit; a first holding material that holds at least part of the first conductor unit; a second holding material that holds at least part of the second conductor unit; and a third holding material that holds at least part of the third conductor unit; wherein the plane that includes the first conductor unit, the plane that includes the second conductor unit, and the plane that includes the third conductor unit are perpendicular to one another.  
      In accordance with one aspect of the present invention, an antenna comprises:  
      first through third conductor units, wherein first through third planes are three virtual planes that share one point and are perpendicular to one another, the first through third conductor units are connected to one another, the first conductor unit is placed along the first plane; the second conductor unit is placed along the second plane; and the third conductor unit is placed along the third plane.  
      In accordance with one aspect of the present invention, a noncontact data transmitter and receiver comprises: an antenna; and an IC chip that is connected to the antenna; wherein the antenna comprises first through third conductor units wherein first through third planes being three virtual planes that share one point and are perpendicular to one another, the first through third conductor units being connected to one another so as to form a loop-like shape, the first conductor unit being placed along the first plane, the second conductor unit being placed along the second plane, the third conductor unit is placed along the third plane; the IC chip performs an operation in accordance with a control signal received by the antenna, using the electromotive force generated by radio waves including the control signal; and radio waves for transmitting the information recorded on the IC chip are generated from the antenna.  
      In accordance with one aspect of the present invention, an antenna sheet comprises: first through third partial sheets; first through third conductor units wherein folding is performed at the boundary between each two of the first through third partial sheets, so as to arrange the first through third partial sheets in a L-like shape and to form first through third planes that share one point and are perpendicular to one another; the first conductor unit and the second conductor unit are connected to each other; and the second conductor unit and the third conductor unit are connected to each other.  
      Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       FIG. 1  illustrates a perspective view of the structure of a noncontact data transmitter and receiver in accordance with a first embodiment of the present invention;  
       FIGS. 2A and 2B  illustrate schematic views of example structures of noncontact data transmitters and receivers in accordance with the first embodiment;  
       FIGS. 3A through 3C  illustrate perspective views of other example structures of concontact data transmitters and receivers in accordance with the first embodiment;  
       FIGS. 4A and 4B  illustrate schematic views of example structures of noncontact data transmitters and receivers in accordance with a second embodiment of the present invention;  
       FIG. 5  illustrates a schematic view of another example structure of a noncontact data transmitter and receiver in accordance with the second embodiment;  
       FIGS. 6A and 6B  illustrate schematic views of example structures of noncontact data transmitters and receivers in accordance with a third embodiment of the present invention;  
       FIGS. 7A through 7C  illustrate modifications of noncontact data transmitters and receivers in accordance with the respective embodiments;  
       FIG. 8  illustrates a schematic view of IC chip formation positions in accordance with each of the embodiments;  
       FIG. 9  illustrates a perspective view of a noncontact data transmitter and receiver attached to an object in accordance with each of the embodiments;  
       FIGS. 10A through 10C  illustrate schematic views of example structures of communicator sheets in accordance with a fourth embodiment of the present invention;  
       FIGS. 11A and 11B  illustrate schematic views of other example structures of communicator sheets in accordance with the fourth embodiment;  
       FIGS. 12A through 12D  illustrate schematic view of other example structures of communicator sheets in accordance with the fourth embodiment;  
       FIG. 13A  illustrates a schematic view of the structure of a communicator loop in accordance with a fifth embodiment of the present invention, and  13 B illustrates a schematic view of the communication loop attached to an ID object in accordance with the fifth embodiment;  
       FIG. 14  shows a flowchart of an operation to be performed by each noncontact transmitter and receiver of the embodiments; and  
       FIGS. 15A and 15B  illustrate schematic views of the structures of conventional antenna devices. 
    
    
     DETAILED DESCRIPTION  
      The following is a description of embodiments of the present invention, with reference to  FIGS. 1 through 14 .  
      [First Embodiment]  
       FIG. 1  is a perspective view of the structure of a noncontact data transmitter and receiver in accordance with this embodiment. As shown in  FIG. 1 , the noncontact data transmitter and receiver  2  includes an antenna device and an IC chip (not shown). The antenna device includes an antenna  4  and a holding block  3 . The antenna  4  includes first conductors  5   a  and  5   b  (a first conductor unit), second conductors  6   a  and  6   b  (a second conductor unit), and third conductors  7   a  and  7   b  (a third conductor unit). In the noncontact data transmitter and receiver  2 , the first through third conductors ( 5   a ,  5   b ,  6   a ,  6   b ,  7   a , and  7   b ) forms a loop-like shape, and are connected to the IC chip (not shown).  
      Having the IC chip performing data processing and the antenna  4 , the noncontact data transmitter and receiver  2  communicates with external devices through radio waves or electromagnetic waves. For example, upon receipt of radio waves (including a control signal) from an external device, the noncontact data transmitter and receiver  2  generates (induced) electromotive force by virtue of the operation of the antenna of the noncontact data transmitter and receiver  2 . Using the electromotive force, the IC chip performs data processing in accordance with the control signal, and the processed result is transmitted from the antenna  4  through carrier waves.  
      The holding block  3  is formed by molding polyimide or another suitable substance into a rectangular parallelepiped (such as a cube), and holds the conductor units  5  through  7  in a wound state. The holding block  3  may be made of any material that does not cut off radio waves. The IC chip is attached to the holding block  3 . As shown in  FIG. 1 , one of the corners of the holding block  3  (a rectangular parallelepiped) is “A”, and the three planes sharing the corner A and being perpendicular to one another are “P”, “Q”, and “R”. In  FIG. 1 , the normal directions of the planes P, Q, and R are z-direction, y-direction, and x-direction, respectively.  
      Here, the first conductor unit  5  ( 5   a  and  5   b ) is placed along the plane P (on the plane P), the second conductor unit  6  ( 6   a  and  6   b ) is placed along the plane Q (on the plane Q), and the third conductor unit  7  ( 7   a  and  7   b ) is placed along the plane R (on the plane R). The first conductors  5   a  and  5   b  are placed in the vicinities of two sides of the plane P, with the two sides being not in contact with the corner A. Accordingly, the first conductors  5   a  and  5   b  are arranged parallel to the two sides. The second conductors  6   a  and  6   b  are placed in the vicinities of two sides of the plane Q, with the two sides being not in contact with the corner A. Accordingly, the second conductors  6   a  and  6   b  are arranged parallel to the two sides. The third conductors  7   a  and  7   b  are placed in the vicinities of two sides of the plane R, with the two sides being not in contact with the corner A. Accordingly, the third conductors  7   a  and  7   b  are arranged parallel to the two sides. With the holding block  3  being a cube, for example, the antenna  4  can be projected in any of the x-, y-, and z-directions, and the areas of the respective projection figures are uniform and substantially the largest. Thus, the antenna  4  can receive radio waves (signals) with high intensity from any direction, and the reception accuracy is uniform for all the directions.  
      The load on the antenna  4  is only equivalent to the six sides (the first conductors  5   a  and  5   b , the second conductors  6   a  and  6   b , and the third conductors  7   a  and  7   b ).  
      Accordingly, the loss at the antenna can be halved, and the capacity of electric power that can be consumed in the circuit such as the IC chip can be made larger.  
      The antenna  4  has a very simple structure, with the six sides being formed into a loop-like shape along the planes P, Q, and R (the three planes that share the corner A of the rectangular parallelepiped and are perpendicular to one another). Accordingly, a two-dimensional or one-dimensional material can be readily formed into a three-dimensional structure, as will be described later. Thus, not only the production costs but also the storage and transportation costs can be dramatically reduced.  
      As shown in  FIG. 2A , the antenna  4  is a loop formed by conductors. As shown in  FIG. 2B , the antenna  4  may also be formed with several loops. In any case, the IC chip is connected to either end of the conductors. In the case of the several loops, the conductors are wound in the same direction (counterclockwise in the drawing). In the case of the several loops, each of the conductors ( 5   a ,  5   b ,  6   a ,  6   b ,  7   a , and  7   b ) is formed with several conductive lines.  
      The holding block  3  has grooves or step portions at the locations at which the respective conductors are to be placed, so that the conductors can be easily wound and maintain a good wound state (see  FIGS. 7A and 7B ). Also, guides through which the conductors extend may be provided at the corners at which the conductors are bent.  
      Alternatively, without such guides, the conductors may be wound via the three opposite corners of the three planes from the corner A (see  FIG. 3C ).  
      The IC chip may be provided on the surface of the holding material, so as to be inserted to the conductors, as indicated by positions D 1  and D 2  in  FIG. 8 . The IC chip may be provided inside the holding block  3 , as indicated by position D 3  in  FIG. 8 .  
      Ultrasonic welding may be performed to connect the antenna  4  and the IC chip. However, any other connecting technique may be employed.  
      The noncontact data transmitter and receiver may be formed as shown in  FIG. 3A .  
      That is, for example, in the noncontact data transmitter and receiver  2 α, the first conductor unit  5  is formed along the plane P (on the plane P), the second conductor unit  6  is formed along the plane Q (on the plane Q), and the third conductor unit  7  is formed along the plane R (on the plane R). The first conductor unit  5  extends along a diagonal line on the plane P that does not include the corner A. The second conductor unit  6  extends along a diagonal line on the plane Q that does not include the corner A. The third conductor unit  7  extends along a diagonal line on the plane R that does not include the corner A.  
      It is also possible to employ a structure shown in  FIG. 3B . That is, for example, in a noncontact data transmitter and receiver  2 α, the first conductor unit  5  is formed along the plane P (on the plane P), the second conductor unit  6  is formed along the plane Q (on the plane Q), and the third conductor unit  7  is formed along the plane R (on the plane R).  
      The first conductor unit  5  extends along the circumferential portion of a quadrant on the plane P that includes the corner A. The second conductor unit  6  extends along the circumferential portion of a quadrant on the plane Q that includes the corner A. The third conductor unit  7  extends along the circumferential portion of a quadrant on the plane R that includes the corner A. With this structure, the areas of the respective projection figures in the x-direction, the y-direction, and the z-direction of the antenna  4  are also uniform, and the above described effects can be achieved.  
      The noncontact data transmitter and receiver may also be formed as shown in  FIG. 3C . That is, for example, in the noncontact data transmitter and receiver  2 γ, the first conductor unit  5  extends from one of the two sides of the plane P that include the corner A (from the vicinity of the opposite end of the side from the corner A) to the other one of the two sides of the plane P that include the corner A (to the vicinity of the opposite end of the side from the corner A) through the opposite corner Bp from the corner A. The second conductor unit  6  extends from one of the two sides of the plane Q that include the corner A (from the vicinity of the opposite end of the side from the corner A) to the other one of the two sides of the plane Q that include the corner A (to the vicinity of the opposite end of the side from the corner A) through the opposite corner Bq from the corner A. The third conductor unit  7  extends from one of the two sides of the plane R that include the corner A (from the vicinity of the opposite end of the side from the corner A) to the other side of the two sides of the plane R that include the corner A (to the vicinity of the opposite end of the side from the corner A) through the opposite corner Br from the corner A. With this arrangement, the first conductor unit  5  extends along the plane P, the second conductor unit  6  extends along the plane Q, and the third conductor unit  7  extends along the plane R, so that the first through third conductor units  5  through  7  form a loop.  
       FIG. 9  shows an example of the noncontact data transmitter and receiver attached to an object. As shown in  FIG. 9 , the noncontact data transmitter and receiver may be attached to corner C 1  inside the box to house an ID object, or may be attached to two corners C 1  and C 2  (in this manner, the reception range is widened). It is of course possible to attach the noncontact data transmitter and receiver to the exterior of the box, or to a given portion of a cushioning material to be packed together with an ID object in the box (to a corner of a styrene foam material, for example). Alternatively, the noncontact data transmitter and receiver may be attached directly to an ID object. In the cases where the noncontact data transmitter and receiver is attached to the exterior of the box or directly to an ID object, the structures shown in  FIGS. 4A, 4B ,  6 A, and  6 B or other suitable structures can be employed.  
      The noncontact data transmitter and receiver  2  may perform an operation shown in  FIG. 14 , for example. First, the antenna  4  receives radio waves from a reader/writer (S 1 ). The IC chip is activated by the electromotive force caused by resonance (S 2 ). The information in the IC chip is read out, and necessary procedures are carried out (S 3 ). The signal indicating the processing result is transmitted from the antenna  4  to the reader/writer (S 4 ).  
      [Second Embodiment]  
      A noncontact data transmitter and receiver in accordance with a second embodiment of the present invention has a holding material formed with three connected holding walls. This structure is shown in  FIG. 4A . The noncontact data transmitter and receiver  10  includes an antenna device and an IC chip. The antenna device is formed with an antenna  14  and a holding material. The antenna  14  includes first conductors  15   a  and  15   b  (a first conductor unit), second conductors  16   a  and  16   b  (a second conductor unit), and third conductors  17   a  and  17   b  (a third conductor unit). In this noncontact data transmitter and receiver  10 , the first through third conductor units form a loop-like structure, and are connected to the IC chip.  
      The noncontact data transmitter and receiver  10  includes the antenna  14  and the IC chip that performs data processing, and communicates with external devices through radio waves or electromagnetic waves. For example, upon receipt of radio waves (including a control signal) from an external device, the noncontact data transmitter and receiver  10  generates (induced) electromotive force by virtue of the operation of the antenna of the noncontact data transmitter and receiver  10 . Using the electromotive force, the IC chip performs data processing in accordance with the control signal, and the processing result is transmitted from the antenna  14  through carrier waves.  
      The holding material  13  has three holding walls Pw, Qw, and Rw. The holding walls Pw, Qw, and Rw are designed to share corner A and be perpendicular to one another. The holding material  13  holds conductor units  15  through  17  in a wound state.  
      The IC chip is also attached to the holding material  13 . The holding material  13  can be formed by bending a sheet made of polyimide or other suitable material (described later).  
      The normal directions of the holding walls Pw, Qw, and Rw are x+-direction, z+-direction, and y+-direction, and the opposite directions to the normal directions are x−-direction, z−-direction, and y−-direction, respectively.  
      The first conductor unit  15  ( 15   a  and  15   b ) is placed along the inner face (the face on the x− side) of the holding wall Pw (on the inner face of Pw). The second conductor unit  16  ( 16   a  and  16   b ) is placed along the inner face (the face on the z− side) of the holding wall Qw (on the inner face of Qw). The third conductor unit  17  ( 17   a  and  17   b ) is placed along the inner face (the face on the y− side) of the holding wall Rw (on the inner face of Rw). The first conductors  15   a  and  15   b  are placed in the vicinities of two sides of the inner face of the holding wall Pw, with the two sides not including the corner A. Accordingly, the first conductors  15   a  and  15   b  are arranged parallel to the two sides, respectively (the first conductor  15   a  extends in the y-direction, while the first conductor  15   b  extends in the z-direction). The second conductors  16   a  and  16   b  are placed in the vicinities of two sides of the inner face of the holding wall Qw, with the two sides not including the corner A. Accordingly, the second conductors  16   a  and  16   b  are arranged parallel to the two sides (the second conductor  16   a  extends in the x-direction, while the second conductor  16   b  extends in the y-direction). The third conductors  17   a  and  17   b  are placed in the vicinities of two sides of the inner face of the holding wall Rw, with the two sides not including the corner A. Accordingly, the third conductors  17   a  and  17   b  are arranged parallel to the two sides (the third conductor  17   a  extends in the z-direction, while the third conductor  17   b  extends in the x-direction).  
      With the holding walls having uniform square shapes, the figures obtained by projecting the antenna  14  in the x-, y-, and z-directions have uniform areas, and the areas are the maximum areas that can be achieved with respect to the volume of the holding material  13 . Accordingly, the antenna  14  can receive radio waves (signals) with high intensity from any direction, and the reception accuracy is uniform in all the directions.  
      Although the conductor units are placed on the inner faces of the holding walls in  FIG. 15A , one or all of the conductor units may be formed on the outer faces of the holding walls (the face on the x+-side of Pw, the face on the y+-side of Qw, and the face on the z+-side of Rw), as shown in  FIG. 4B .  
      The noncontact data transmitter and receiver of this embodiment may have a structure shown in  FIG. 5 . That is, for example, in a noncontact data transmitter and receiver  10 b, the first conductor unit  15  ( 15   a  and  15   b ) is insert-molded at the locations of the inside of the holding wall Pw corresponding to the vicinities of two sides of the outer face of the holding wall Pw, with the two sides not including the corner A. The second conductor unit  16  ( 16   a  and  16   b ) is insert-molded at the locations of the inside of the holding wall Qw corresponding to the vicinities of two sides of the outer face of the holding wall Qw, with the two sides not including the corner A. The third conductor unit  17  ( 17   a  and  17   b ) is insert-molded at the locations of the inside of the holding wall Rw corresponding to the vicinities of two sides of the outer face of the holding wall Rw, with the two sides not including the corner A.  
      Each of the holding walls for example has grooves or step portions at the locations at which the conductors are to be placed, so that the conductors can be easily wound and maintain a good wound state (see  FIGS. 7A and 7B ). Also, guides through which the conductors extend may be provided at the corners at which the conductors are bent. Alternatively, without such guides, the conductors may be wound via the three opposite corners of the three planes from the corner A.  
      The noncontact data transmitter and receiver  10  of this embodiment may be attached directly to an ID object or to (either the inside of the outside of) the packing box of an ID object. The noncontact data transmitter or receiver  10  may also be attached to a given portion of a cushioning material to be packed together with an ID object in the box (to a corner of a styrene foam material, for example).  
      [Third Embodiment]  
      A noncontact transmitter and receiver of a third embodiment of the present invention has a holding material formed with three connected holding frame units that constitute a holding frame. This structure is shown in  FIG. 6A . The noncontact data transmitter and receiver  20  includes an antenna device and an IC chip. The antenna device is formed with an antenna and a holding material. The antenna  24  includes first conductors  25   a  and  25   b  (a first conductor unit), second conductors  26   a  and  26   b  (a second conductor unit), and third conductors  27   a  and  27   b  (a third conductor unit). In this noncontact data transmitter and receiver  20 , the first through third conductor units form a loop-like structure, and are connected to the IC chip.  
      The noncontact data transmitter and receiver  20  includes the antenna  24  and the IC chip that performs data processing, and communicates with external devices through radio waves or electromagnetic waves. For example, upon receipt of radio waves (including a control signal) from an external device, the noncontact data transmitter and receiver  20  generates (induced) electromotive force by virtue of the operation of the antenna of the noncontact data transmitter and receiver  20 . Using the electromotive force, the IC chip performs data processing in accordance with the control signal, and the processing result is transmitted from the antenna  24  through carrier waves.  100561  The holding material  23  includes a first holding frame unit Pf (Pfa and Pfb), a second holding frame unit Qf (Qfa and Qfb), and a third holding frame unit Rf (Rfa and Rfb). The holding material  23  holds the conductor units  25  through  27  in a wound state. Each of the holding frame units is made of polyimide or other suitable material. The IC chip is also attached to the holding material  23 . As shown in  FIG. 6A , the holding frame units have uniform square shapes. Three virtual planes (hypothetical planes that do not actually exist) that share the point A and are perpendicular to one another are set as planes p, q, and r. The normal directions of the planes p, q, and r are set as x-, z-, and y-directions, respectively.  
      The first holding frame unit Pf (Pfa and Pfb) is placed along the plane p, the second holding frame unit Qf (Qfa and Qfb) is placed along the plane q, and the third holding frame unit Rf (Rfa and Rfb) is placed along the plane r. Further, the first holding frame unit Pf (Pfa and Pfb) is placed in the vicinities of two sides of the plane p, with the two sides not including the corner A. Accordingly, the first holding frame unit Pf is arranged parallel to the two sides (the first conductor  25   a  extends in the y-direction, while the first conductor  25   b  extends in the z-direction). The second holding frame unit Qf (Qfa and Qfb) is placed in the vicinities of two sides of the plane q, with the two sides not including the corner A. Accordingly, the second holding frame unit Qf is arranged parallel to the two sides (the second conductor  26   a  extends in the x-direction, while the second conductor  26   b  extends in the y-direction). The third holding frame unit Rf (Rfa and Rfb) is placed in the vicinities of two sides of the plane r, with the two sides not including the corner A. Accordingly, the third holding frame unit Rf is arranged parallel to the two sides (the third conductor  27   a  extends in the z-direction, while the third conductor  27   b  extends in the x-direction).  
      The first conductor unit  25  ( 25   a  and  25   b ) is placed on the first holding frame unit Pf (Pfa and Pfb), the second conductor unit  26  ( 26   a  and  26   b ) is placed on the second holding frame unit Qf (Qfa and Qfb), and the third conductor unit  27  ( 27   a  and  27   b ) is placed on the third holding frame unit Rf (Rfa and Rfb).  
      With the planes p through r having uniform square shapes, the figures obtained by projecting the antenna  24  in the x-, y-, and z-directions have uniform areas, and the areas are the maximum areas that can be achieved with respect to the volume of the holding material  23 . Accordingly, the antenna  24  can receive radio waves (signals) with high intensity from any direction, and the reception accuracy is uniform in any direction.  
      Each of the holding frame units for example has grooves or step portions at the locations at which the conductors are to be placed, so that the conductors can be easily wound and maintain a good wound state (see  FIG. 7C ). Also, guides through which the conductors extend may be provided at the corners at which the conductors are bent.  
      Alternatively, without such guides, the conductors may be wound via the three opposite corners of the three planes from the corner A.  
      The noncontact data transmitter and receiver of this embodiment may have a structure shown in  FIG. 6B . That is, for example, in a noncontact data transmitter and receiver  20 a, the first conductor unit  25  ( 25   a  and  25   b ) is insert-molded inside the first holding frame unit Pf (Pfa and Pfb). The second conductor unit  26  ( 26   a  and  26   b ) is insert-molded inside the second holding frame unit Qf (Qfa and Qfb). The third conductor unit  27  ( 27   a  and  27   b ) is insert-molded inside the third holding frame unit Rf (Rfa and Rfb).  
      The noncontact data transmitter and receiver  20  of this embodiment may be attached directly to an ID object or to (either the inside of the outside of) the packing box of an ID object. The noncontact data transmitter or receiver  20  may also be attached to a given portion of a cushioning material to be packed together with an ID object in the box (to a corner of a styrene foam material, for example).  
      [Fourth Embodiment]  
      In this embodiment, a communicator sheet that forms the noncontact data transmitter and receiver  10  ( 10 □,  10 □) of the second embodiment is described. A three-dimensional noncontact data transmitter and receiver can be formed from a two-dimensional communicator sheet. With this structure, not only the production costs but also the storage and transportation costs can be dramatically reduced. In this embodiment, the sheet plane is x-y plane, and the direction perpendicular to the sheet plane is z-direction.  
      A communicator sheet  30  shown in  FIG. 10A  is formed with four partial sheets  30   p ,  30   q ,  30   r , and  30   s  (a connecting sheet) that share the corner A and are connected to one another. The partial sheets have uniform square shapes. The partial sheets  30   p ,  30   q , and  30   r  have a first conductor unit  35  ( 35   a  and  35   b ), a second conductor unit  36  ( 36   a  and  36   b ), and a third conductor unit  37  ( 37   a  and  37   b ), respectively. Although not shown in the drawing, an IC chip that is connected to the conductor units is attached to the communicator sheet  30 . The first through third conductor units  35  through  37  are connected directly to one another or are connected to one another via the IC chip. The partial sheets  30   s  and  30   p  are adjacent to each other, with line L 1  extending through the point A being the boundary. The partial sheets  30   p  and  30   q  are adjacent to each other, with line L 2  extending through the point A being the boundary. The partial sheets  30   q  and  30   r  are adjacent to each other, with line L 3  extending through the point A being the boundary. Also, a score line is formed through the boundary between the partial sheet  30   r  and  30   s.    
      The first conductors  35   a  and  35   b  are placed in the vicinities of two sides of the front face of the partial sheet  30   p , with the two sides not including the corner A.  
      Accordingly, the first conductors  35   a  and  35   b  are arranged parallel to the two sides, respectively (the first conductor  35   a  extends in the y-direction, while the first conductor  35   b  extends in the x-direction). The second conductors  36   a  and  36   b  are placed in the vicinities of two sides of the front face of the partial sheet  30   q , with the two sides not including the corner A. Accordingly, the second conductors  36   a  and  36   b  are arranged parallel to the two sides, respectively (the second conductor  36   a  extends in the x-direction, while the second conductor  36   b  extends in the y-direction). The third conductors  37   a  and  37   b  are placed in the vicinities of two sides of the back face of the partial sheet  30   r , with the two sides not including the corner A. Accordingly, the third conductors  37   a  and  37   b  are arranged parallel to the two sides, respectively (the third conductor  37   a  extends in the y-direction, while the third conductor  37   b  extends in the x-direction). A connecting portion for the connection with the conductor  35   a  is provided on the front face of the partial sheet  30   s . This connecting portion is a small extended portion at the end of the first conductor  35   a  on the side of the partial sheet  30   s . The second conductor  36   b  (on the front face of the partial sheet) and the third conductor  37   a  (on the back face of the partial sheet) are connected to each other with a through-hole H, for example.  
      This communicator sheet  30  is assembled in the following manner, so that the noncontact data transmitter and receiver of the second embodiment can be produced. First, with the line L 2  and the score line being a folding line, folding (forward from the sheet surface) is performed so that the partial sheets  30   q  and  30   r  become parallel to the z-direction (the direction perpendicular to the sheets). With the line L 3  being the folding line, folding is then performed so that the partial sheet  30   r  becomes perpendicular to the partial sheets  30   q  and  30   p  (the score line is placed on the line L 1 ). With the line L 1  being the folding line, folding is further performed so that the partial  30   s  is placed on the partial sheet  30   r . With this arrangement, the end portion G of the third conductor  37   b  placed on the back face of the partial sheet  30   r  is overlapped on the connecting portion placed on the partial sheet  30   s , and the antenna  14  is formed as shown in  FIG. 4B  for example. That is, the partial sheet  30   p  forms the holding wall Pw and the first conductor unit  15  shown in  FIG. 4B , the partial sheet  30   q  forms the holding wall Qw and the second conductor unit  16  shown in  FIG. 4B , and the partial sheet  30   r  forms the holding wall Rw and the third conductor unit  17  shown in  FIG. 4B .  
      The communicator sheet  30  may be modified as shown in  FIGS. 10B and 10C .  
      The partial sheet  30   s  of  FIG. 10A  is designed in the form of a small trapezoid as a margin  30   t  (a connecting sheet), and the connecting portion is formed on the margin  30   t  (see  FIG. 10B ). The end portion G of the third conductor  37   b  placed on the back face of the partial sheet  30   r  is overlapped on the connecting portion of the margin  30   t , so as to form the antenna  14 . The margin  30   t  may be only slightly larger than the connecting portion (see  FIG. 10C ).  
      The communicator sheet in accordance with this embodiment may be formed as shown in  FIG. 11A . A communicator sheet  40  is formed with four partial sheets  40   p ,  40   q ,  40   r , and  40   s  (a connecting sheet) that share the point A and are connected to one another.  
      The partial sheets have uniform square shapes. The partial sheets  40   p ,  40   q , and  40   r  include a first conductor unit  45  ( 45   a  and  45   b ), a second conductor unit  46  ( 46   a  and  46   b ), and a third conductor unit  47  ( 47   a  and  47   b ), respectively. Although not shown in the drawing, an IC chip to be connected to the conductor units is provided on the communicator sheet  40 . The first through third conductor units  45  through  47  are connected directly to one another or are connected to one another via the IC chip. The partial sheets  40   s  and  40   p  are adjacent to each other, with line L 1  extending through the point A being the boundary. The partial sheets  40   p  and  40   q  are adjacent to each other, with line L 2  extending through the point A being the boundary. The partial sheets  40   q  and  40   r  are adjacent to each other, with line L 3  being the boundary. The partial sheets  40   r  and  40   s  are adjacent to each other, with line L 4  being the boundary. Further, a diagonal line including the point A on the partial sheet  40   s  is line L 5 .  
      The first conductors  45   a  and  45   b  are placed in the vicinities of two sides of the front face of the partial sheet  40   p , with the two sides not including the corner A.  
      Accordingly, the first conductors  45   a  and  45   b  are arranged parallel to the two sides, respectively (the first conductor  45   a  extends in the y-direction, while the first conductor  45   b  extends in the x-direction). The second conductors  46   a  and  46   b  are placed in the vicinities of two sides of the front face of the partial sheet  40   q , with the two sides not including the corner A. Accordingly, the second conductors  46   a  and  46   b  are arranged parallel to the two sides, respectively (the second conductor  46   a  extends in the x-direction, while the second conductor  46   b  extends in the y-direction). The third conductors  47   a  and  47   b  are placed in the vicinities of two sides of the front face of the partial sheet  40   r , with the two sides not including the corner A. Accordingly, the third conductors  47   a  and  47   b  are arranged parallel to the two sides, respectively (the third conductor  47   a  extends in the y-direction, while the third conductor  47   b  extends in the x-direction). A connecting portion i for the connection with the conductor  45   a  is provided on the front face of the partial sheet  40   s . This connecting portion i is a small extended portion at the end of the first conductor  45   a  on the side of the partial sheet  40   s . Further, a connecting portion j for the connection with the conductor  47   b  is provided on the front face of the partial sheet  40   s . This connecting portion j is a small extended portion of the third conductor  47   b  on the side of the partial sheet  40   s.    
      This communicator sheet  40  is assembled in the following manner, so that the noncontact data transmitter and receiver of the second embodiment can be produced.  
      First, with the line L 2  and the line L 4  (forming one straight line) being a folding line, folding backward from the sheet face is performed so that the partial sheets  40   q  and  40   r  become parallel to the z-direction (the direction perpendicular to the sheets). With the line L 5  being the folding line, the partial sheet  40   s  is folded inward, so that the line L 4  is overlapped on the line L 1 . In this manner, the connecting portion i and the connecting portion j provided on the partial sheet  40   s  are overlapped on each other, and the antenna  14  shown in  FIG. 4A  is formed. Accordingly, the partial sheet  40   p  forms the holding wall Pw and the first conductor unit  15  shown in  FIG. 4A , the partial sheet  40   q  forms the holding wall Rw and the third conductor unit  17  shown in  FIG. 4A , and the partial sheet  40   r  forms the holding wall Qw and the second conductor unit  16  shown in  FIG. 4A .  
      As shown in  FIG. 11B , the communicator sheet  40  may have a notch formed in the partial sheet  40   s  (the connecting sheet) of  FIG. 11 A  by cutting the partial sheet  40   s  along a line extending from the vicinity of the connecting portion i to the point A and a line extending from the vicinity of the connecting portion j to the point A.  
      The communicator sheet in accordance with this embodiment may also be formed as shown in  FIG. 12A . A communicator sheet  50  is formed with four partial sheets  50   p ,  50   q ,  50   r , and  50   s  that share point A and are connected to one another. The partial sheets have uniform square shapes. The partial sheets  50   p ,  50   q , and  50   r  include a first conductor unit  55  ( 55   a  and  55   b ), a second conductor unit  56  ( 56   a  and  56   b ), and a third conductor unit  57  ( 57   a  and  57   b ), respectively. Although not shown in the drawing, an IC chip to be connected to the conductor units is provided on the communicator sheet  50 .  
      The first through third conductor units  55  through  57  are connected directly to one another or are connected to one another via the IC chip. The partial sheets  50   s  and  50   p  are adjacent to each other, with line L 1  extending through the point A being the boundary. The partial sheets  50   p  and  50   q  are adjacent to each other, with line L 2  extending through the point A being the boundary. The partial sheets  50   q  and  50   r  are adjacent to each other, with line L 3  being the boundary. The partial sheets  50   r  and  50   s  are adjacent to each other, with line L 4  being the boundary. Further, a diagonal line including the point A on the partial sheet  50   s  is line L 5 .  
      The first conductors  55   a  and  55   b  are placed in the vicinities of two sides of the front face of the partial sheet  50   p,  with the two sides not including the corner A.  
      Accordingly, the first conductors  55   a  and  55   b  are arranged parallel to the two sides, respectively (the first conductor  55   a  extends in the y-direction, while the first conductor  55   b  extends in the x-direction). The second conductors  56   a  and  56   b  are placed in the vicinities of two sides of the front face of the partial sheet  50   q , with the two sides not including the corner A. Accordingly, the second conductors  56   a  and  56   b  are arranged parallel to the two sides, respectively (the second conductor  56   a  extends in the x-direction, while the second conductor  56   b  extends in the y-direction). The third conductors  57   a  and  57   b  are placed in the vicinities of two sides of the front face of the partial sheet  50   r , with the two sides not including the corner A. In this manner, the third conductors  57   a  and  57   b  are arranged parallel to the two sides, respectively (the third conductor  57   a  extends in the y-direction, while the third conductor  57   b  extends in the x-direction).  
      Further, a connecting portion k 1  to be connected to an end portion F of the conductor  55   a  is provided along the line L 1  on the front face of the partial sheet  50   p . A connecting portion k 2  to be connected to an end portion G of the conductor  57   b  is provided along the line L 4  on the front face of the partial sheet  50   r . The two connecting portions k 1  and k 2  are connected in the vicinity of the corner A.  
      This communicator sheet  50  is assembled in the following manner, so that the noncontact data transmitter and receiver of the second embodiment can be produced.  
      First, with the line L 2  and the line L 4  (forming one straight line) being the folding line, folding backward from the sheet face is performed so that the partial sheets  50   q  and  50   r  become parallel to the z-direction (the direction perpendicular to the sheets). With the line L 5  being the folding line, the partial sheet  50   s  is folded inward, and, with the line L 3  being the folding line, the partial sheet  50   r  is folded, so that the partial sheet  50   r  becomes perpendicular to the partial sheets  50   p  and the partial sheet  50   q . Since the end portion F of the conductor  55   a  and the end portion G of the conductor  57   b  are connected with the connecting portions k 1  and k 2  in the first place, the antenna  14  shown in  FIG. 4A  is formed. Accordingly, the partial sheet  50   p  forms the holding wall Pw and the first conductor unit  15  shown in  FIG. 4A , the partial sheet  50   q  forms the holding wall Rw and the third conductor unit  17  shown in  FIG. 4A , and the partial sheet  50   r  forms the holding wall Qw and the second conductor unit  16  shown in  FIG. 4A .  
      In the communicator sheet  50 , a score line may be formed through the line L 4  of  FIG. 12A  (see  FIG. 12B ), or the partial sheet  50   s  of  FIG. 12A  may be replaced with a notch (see  FIG. 12C ), or the partial sheet  50   s  of  FIG. 12A  may be made smaller and used as a margin (see  FIG. 12D ). In any of the above cases, with the line L 2  and the line L 4  (forming one straight line) being the folding line, folding backward from the sheet face is performed so that the partial sheets  50   q  and  50   r  become parallel to the z-direction (the direction perpendicular to the sheet). With the line L 3  being the folding line, the partial sheet  50   r  is folded so that the partial sheet  50   r  becomes perpendicular to the partial sheet  50   p  and the partial sheet  50   q  (so that the line L 1  and the line L 4  are overlapped on each other). Since the end portion F of the conductor  55   a  and the end portion G of the conductor  57   b  are connected with the connecting portions k 1  and k 2  in the first place, the antenna  14  as shown in  FIG. 4A  is formed.  
      In any of the above described structures, an adhesive face may be formed on at least a part of one or more of the partial sheets  50 , so that the partial sheets can be attached to a packing box for an ID object. The communicator sheet  50  of this embodiment may be attached directly to an ID object or to (either the inside of the outside of) the packing box of an ID object. The communicator sheet  50  of this embodiment may also be attached to a given portion of a cushioning material to be packed together with an ID object in the box (to a corner of a styrene foam material, for example).  
      Although the communicator sheet of this embodiment includes an IC chip, it may be formed as an antenna sheet only with conductors or antennas (not including an IC chip). In such a case, an IC chip can be attached to the structure after the antenna sheet is assembled. The antenna sheet may have any of the structures shown in  FIGS. 10A  through C and  FIGS. 11A and 11B .  
      [Fifth Embodiment]  
      To produce the noncontact data transmitter and receiver of the third embodiment, a communicator loop shown in  FIG. 13A  can be formed. A communicator loop  60  has six holding materials  61   a  through  61   f  attached at intervals to a loop-like conductor unit  66 .  
      Although not shown, an IC chip to be connected to the conductor unit is attached to the communicator loop  60 . The conductor unit  66  is made of a material that easily bends, while the holding members  61   a  through  61   f  are made of a material that is difficult to bend. With this arrangement, the communicator loop  60  can have the following three-dimensional structure. Planes p, q, and r having uniform square shapes are virtual planes that share corner A and are perpendicular to one another. The holding materials  61   a  and  61   b  are arranged along the plane p, the holding materials  61   c  and  61   d  are arranged along the plane q, and the holding materials  61 e and  61   f  are arranged along the plane r. The holding materials  61   a  and  61   b  are placed in the vicinity of two sides of the plane p, with the two sides not including the corner A. Accordingly, the holding materials  61   a  and  61   b  are arranged parallel to the two sides, respectively. The holding materials  61   c  and  61   d  are placed in the vicinity of two sides of the plane q, with the two sides not including the corner A. Accordingly, the holding materials  61   c  and  61   d  are arranged parallel to the two sides, respectively. The holding materials  61   e  and  61   f  are placed in the vicinity of two sides of the plane r, with the two sides not including the corner A. Accordingly, the holding materials  61   e  and  61   f  are arranged parallel to the two sides, respectively. The conductor unit  66  is looped through the respective holding materials  61   a  through  61   f .  
      With this three-dimensional structure, the communicator loop  60  can be attached to an ID object (see  FIG. 13B ), and the same effects as those of the third embodiment can be achieved.  
      A communicator loop can be formed only with conductors, without such holding materials as the holding materials  61  a through  61   f  of  FIG. 13A . In this case, folding lines or score lines are formed at several positions in the conductor unit. Alternatively, several conductors made of different materials with various degrees of flexibility may be connected and used as a conductor unit. With this arrangement, a two-dimensional structure can be turned into the above three-dimensional structure. Also, a communicator loop can be formed by looping a conductor covered with a coating. In this case, folding lines or score lines are formed at several positions in the coating. The coating may be formed with different coating materials with various degrees of flexibility. With this arrangement, a two-dimensional structure can be turned into the above three-dimensional structure. Further, a fixing member that hardly bends may be attached to a loop-like constant conductor. In this case, protrusions can be formed on the conductor, so as to prevent the fixing member from shifting, or grooves can be formed in the fixing member. With such arrangement, transportation becomes smoother.  
      The communicator loop  60  of this embodiment may be attached directly to an ID object or to (either the inside of the outside of) the packing box of an ID object. The communicator loop  60  of this embodiment may also be attached to a given portion of a cushioning material to be packed together with an ID object in the box (to a corner of a styrene foam material, for example).  
      As described above, with the antenna device of the present invention, the length of the loop formed by a three-dimensional antenna can be dramatically reduced, and the power loss can also be dramatically reduced. More specifically, the antenna device of the present invention can receive radio waves from various directions and generate large electromotive force. Accordingly, if the antenna device is implemented in a noncontact data transmitter and receiver, for example, the data transmission and reception capacity can be increased. Furthermore, the antenna device has a very simple structure, with three conductor units parallel to the respective planes being formed into a loop. Thus, the production costs can be reduced. Also, the antenna device may be converted from a two-dimensional structure to a three-dimensional structure. In this manner, not only the production costs but also the storage and transportation costs can be dramatically reduced.  
      While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.