Abstract:
A method and an apparatus for inspecting radio frequency identification (RFID) tags which utilize a way of shielding for inspecting whether RFID tags function properly or not. The method of the present invention comprises steps of: reading a plurality of RFID tags in a readable zone; and determining whether there is any malfunctional RFID tag in the plurality of RFID tags. If all the plurality of RFID tags function properly, the method will check a next plurality of RFID tags. If there is at least one unreadable RFID tag, the at least one malfunctional RFID tag will be found by shielding one or the plurality of RFID tags. By means of the disclosure in the present invention, the present method and apparatus are capable of improving the efficiency during inspection and simplifying the design of a readable zone.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to an inspecting method and apparatus and, more particularly, to a method and an apparatus for inspecting radio frequency identification (RFID) tags by determining whether there is any malfunctional RFID tag and then determining where the malfunctional RFID tag is located using a way of shielding. 
         [0003]    2. Description of the Prior Art 
         [0004]    Since 2004, the radio frequency identification (RFID) technology has become one of the top 10 breakthrough technologies of the century. The RFID technology has been widely used in, for example, logistics, inventory management, national securities, medical science and public health. 
         [0005]    The RFID technology using a reader, RFID tags and middleware and system integration is characterized in that the reader issues radio waves at a specific frequency to the RFID tags to drive the circuitry in the RFID tags to transmit the data in the chip back to the reader. 
         [0006]    An RFID tag comprises an RF integrated circuit (RFIC) and an antenna. An RFID tag is packaged using an an-isotropic conductive paste (ACP) to agglutinate the substrate of the antenna so that the conductive particles in the an-isotropic conductive paste complete the electric circuit. The packaging quality depends on the packaging temperature, the packaging pressure and the packaging time. Therefore, automatized detection after packaging is crucial in quality control and yield improvement when mass production is concerned. 
         [0007]    Please refer to  FIG. 1A  and  FIG. 1B , which are two examples of conventional apparatuses for inspecting RFID tags. In  FIG. 1A , the apparatus  1   a  comprises a carriertape transportation device  10 , a reading device  11  and a moving device  12 . The carriertape transportation device  10  transports a carriertape  101  carrying a plurality of RFID tags  1011 . The reading device  11  is disposed on one side of the carriertape  101 . The reading device  11  comprises a reader  111  covered by a shelter  110  having an opening allowing the reader to read the data in a single RFID tag at a time. The moving device  12  is connected to the reading device  11  so as to drive the reading device  11  to move. In the apparatus  1   a  in  FIG. 1A , the reading device  11  is moved so as to inspect an RFID tag at a time to determine whether there is any malfunctional RFID tag  1012 . Even though the apparatus  1   a  is capable of inspecting every RFID tag, the reading device  11  has problems because of its large size, difficulty in carrying, difficulty in designing the readable zone and time-consuming inspection. 
         [0008]    In  FIG. 1B , the apparatus  1   b  also comprises a carriertape transportation device  10  and a reading device  13  that are similar to those of the apparatus  1   a  in  FIG. 1A . However, reading device  13  of the apparatus  1   b  is not movable. Instead, the carriertape transportation device  10  sequentially moves so that the reading device  13  inspects an RFID tag at a time to determine whether there is any malfunctional RFID tag  1012 , as disclosed in U.S. Pat. No. 6,104,291. Even though the apparatus  1   b  is capable of inspecting every RFID tag, there are problems because it is difficult to design the readable zone and time-consuming in inspection. 
         [0009]    Therefore, there is need in providing a method and an apparatus for inspecting radio frequency identification (RFID) tags to overcome the afore-mentioned problems. 
       SUMMARY OF THE INVENTION 
       [0010]    It is one object of the present invention to provide a method for inspecting radio frequency identification (RFID) tags by determining whether there is any malfunctional RFID tag and then determining where the malfunctional RFID tag is located using a way of shielding. 
         [0011]    It is another object of the present invention to provide an apparatus for inspecting radio frequency identification (RFID) tags, using a reading device to read data in a plurality of RFID tags in a readable zone and using a sheltering device to (progressively) shielding a next one and the previously shielded one(s) of the RFID tags so as to find any malfunctional RFID tag. 
         [0012]    In order to achieve the foregoing objects, the present invention provides a method for inspecting radio frequency identification (RFID) tags, comprising steps of: (a) reading a plurality of RFID tags in a readable zone; and (b) determining whether there is any malfunctional RFID tag in the plurality of RFID tags, and determining where the malfunctional RFID tag is located using a way of shielding if there is any malfunctional RFID tag. 
         [0013]    In order to achieve the foregoing objects, the present invention provides an apparatus for inspecting radio frequency identification (RFID) tags, comprising: a carriertape transportation device, capable of carrying a carriertape carrying a plurality of RFID tags; a reading device, disposed on one side of the carriertape and capable of reading data in the RFID tags on the carriertape in a readable zone; a shelter, capable of shielding to limit the number of the RFID tags to be read by the reading device; and a moving device, connected to the shelter and capable of moving the shelter. 
         [0014]    In order to achieve the foregoing objects, the present invention provides an apparatus for inspecting radio frequency identification (RFID) tags, comprising: a carriertape transportation device, capable of carrying a carriertape carrying a plurality of RFID tags; a reading device, disposed on one side of the carriertape and capable of reading data in the RFID tags on the carriertape in a readable zone; and a sheltering device, capable of shielding to limit the number of the RFID tags to be read by the reading device and capable of varying a shielding area to determine the number of RFID tags. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The objects, spirits and advantages of the preferred embodiment of the present invention will be readily understood by the accompanying drawings and detailed descriptions, wherein: 
           [0016]      FIG. 1A  and  FIG. 1B  are two examples of conventional apparatuses for inspecting RFID tags; 
           [0017]      FIG. 2  is a flow-chart showing the method for inspecting RFID tags according to one embodiment of the present invention; 
           [0018]      FIG. 3  is a flow-chart showing the step of determining whether there is any malfunctional RFID tag of the method for inspecting RFID tags according to a first embodiment of the present invention; 
           [0019]      FIG. 4A ,  FIG. 4B  and  FIG. 4C  are schematic diagrams of an apparatus for inspecting RFID tags according to a first embodiment of the present invention; 
           [0020]      FIG. 5A ,  FIG. 5B  and  FIG. 5C  are examples of an carriertape in an apparatus for inspecting RFID tags according to one embodiment of the present invention; 
           [0021]      FIG. 6A  is an example of a moving device in an apparatus for inspecting RFID tags according to one embodiment of the present invention; 
           [0022]      FIG. 6B  is an example of a moving device in an apparatus for inspecting RFID tags according to another embodiment of the present invention; 
           [0023]      FIG. 7  is a flow-chart showing the step of determining whether there is any malfunctional RFID tag of the method for inspecting RFID tags according to a second embodiment of the present invention; 
           [0024]      FIG. 8A  and  FIG. 8B  are schematic diagrams of an apparatus for inspecting RFID tags according to a second embodiment of the present invention; 
           [0025]      FIG. 9A  and  FIG. 9B  are examples of a sheltering device in an apparatus for inspecting RFID tags according to a second embodiment of the present invention; 
           [0026]      FIG. 10A  and  FIG. 10B  are schematic diagrams of an apparatus for inspecting RFID tags according to a third embodiment of the present invention; and 
           [0027]      FIG. 11A  and  FIG. 11B  are schematic diagrams of an apparatus for inspecting RFID tags according to a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    The present invention providing a method and an apparatus for inspecting radio frequency identification (RFID) tags can be exemplified by the preferred embodiments as described hereinafter. 
         [0029]    The method for inspecting radio frequency identification (RFID) tags according to the present invention comprises two steps. First, a plurality of RFID tags are read in a readable zone. Then, whether there is any malfunctional RFID tag in the plurality of RFID tags is determined. A way of shielding is used to determine where the malfunctional RFID tag is located if there is any malfunctional RFID tag. 
         [0030]    Please refer to  FIG. 2 , which is a flow-chart showing the method for inspecting RFID tags according to one embodiment of the present invention. The method comprises steps described hereinafter. 
         [0031]    First, in Step  20 , the number of RFID tags to be read in a readable zone is set. Then in Step  21 , a carriertape is moved so that RFID tags thereon to be inspected enter the readable zone. In Step  22 , the RFID tags on the carriertape are read. In Step  23 , whether the set number (from Step  20 ) is equal to the number of read RFID tags (from Step  22 ) is determined. If the set number (from Step  20 ) is equal to the number of read RFID tags (from Step  22 ), all the RFID tags in the readable zone are functional and the process goes to Step  25 ; otherwise, it is determined that there is a malfunctional RFID tag if the set number (from Step  20 ) is different from the number of read RFID tags (from Step  22 ) by at least two. Therefore, the process goes to Step  24  to determine where the malfunctional RFID tag is located. Then in Step  25 , whether there is any un-inspected carriertape is determined. The process ends if there is no more un-inspected carriertape; otherwise, the process goes to Step  21  and repeats until all the RFID tags have been inspected. 
         [0032]    Please refer to  FIG. 3 , which is a flow-chart showing the step of determining whether there is any malfunctional RFID tag of the method for inspecting RFID tags according to a first embodiment of the present invention. In the present embodiment, the RFID tags are shielded in a one-by-one manner to determine whether the RFID tags are functional or not. In Step  24 , the process starts with Step  240   a , in which one of the RFID tags in the readable zone is shielded. Then in Step  241   a , the RFID tags in the readable zone are read. Afterwards, the Step  242   a  is performed to determine whether the number of readable RFID tags is reduced. The process goes to Step  243   a  if the number of readable RFID tags is not reduced. In Step  243   a , it is determined and recorded that the shielded RFID tag is malfunctional. Otherwise, if the number of readable RFID tags is reduced, the process goes to Step  244   a  to determine that the shielded RFID tag is functional. Afterwards, in Step  245   a , it is determined whether all the malfunctional RFID tags are found. The process goes to Step  25  if all the malfunctional RFID tags are found; otherwise, the process goes to Step  246   a  to shield a next one of the RFID tags in the readable zone. Then the process returns to Step  241   a  and repeats from Step  241   a  to  245   a  until all the malfunctional RFID tags are found. 
         [0033]    Please refer to  FIG. 4A  to  FIG. 4C , which are schematic diagrams of an apparatus for inspecting RFID tags according to a first embodiment of the present invention. The apparatus  3  comprises a carriertape transportation device  30 , a reading device  32 , a shelter  33  and a moving device  34 . The carriertape transportation device  30  is capable of carrying a carriertape  31  carrying a plurality of RFID tags  311 . The RFID tags  311  can be active smart tags or passive smart tags. The carriertape transportation device  30  can be a roller to transport a reel carriertape, as shown in  FIG. 4A . Alternatively, the carriertape transportation device  30  can be a holder plate to transport a sheet carriertape. 
         [0034]    The reading device  32  is disposed on one side of the carriertape  31  and is capable of reading data in the RFID tags  311  on the carriertape  31  in a readable zone R. The shelter  33  is capable of shielding to limit the number of the RFID tags to be read by the reading device  32 . In the present embodiment, the shelter  33  is formed of a metal material, a wave-breaking material, a wave-absorbing material, a wave-reflecting material or a wave-blocking material and is not limited thereto. In the present embodiment, the shelter  33  comprises a container to fill in with water for wave absorbing. Alternatively, the wave-absorbing material is a composite material or a polymeric material. The moving device  34  is connected to the shelter  33  and is capable of moving the shelter  33 . In one embodiment, a shielding plate  36  is disposed on each of two sides of the reading device  32  to limit the readable zone to avoid the reading device from reading the RFID tags outside the readable zone R. 
         [0035]    In the present embodiment accompanied by  FIG. 3  and  FIG. 4A , there are two malfunctional RFID tags  312  out of 13 RFID tags  311 . Therefore, in the beginning, the reading device reads 11 RFID tags. When Step  240   a  is performed, the moving device  34  moves the shelter  33  to a proper position (a) to shield a RFID tag  301  from communication with the reading device  32 . When the reading device  32  issues a signal, the reading device  32  only reads 10 RFID tags because the RFID tag  301  is shielded by the shelter  33 . In Step  242   a , it is determined that the number of the 10 RFID tags is smaller than the 11 RFID tags by one. Therefore, it is determined that the RFID tag  311  at a position (a) is functional. 
         [0036]    Afterwards, the moving device proceeds to a next position (b) and the steps in  FIG. 3  are performed accompanied by  FIG. 4B . In  FIG. 4C , when the moving device  34  moves the shelter  33  to shield a RFID  312  at a position (c), the reading device  32  reads 11 RFID tags because the RFID  312  at the position (c) is malfunctional. Therefore, in Step  242   a , it is determined that the RFID tag  312  at the position (c) is malfunctional. The steps are repeated until all the malfunctional RFID tags in the readable zone are found. In the present embodiment, another malfunctional RFID is located at a position (d). When the moving device  34  moves to the position (d), all the malfunctional RFID tags can be found. Therefore, even though the RFID tags at a position (e) and a position (f) are not inspected, the process can go to Step  26  for a next carriertape. 
         [0037]    Please refer to  FIGS. 5A ,  5 B and  5 C, which are examples of a carriertape in an apparatus for inspecting RFID tags according to one embodiment of the present invention. In  FIG. 5A  and  FIG. 5B , the carriertape  31  is a rectangular. The carriertape in  FIG. 5A  has a row of RFID tags  311 , while the carriertape In  FIG. 5B  has a plurality of rows of RFID tags  311 . In  FIG. 5C , the carriertape is a disc carriertape and the RFID tags are arranged in at least one row on the disc carriertape. However, the present invention is not limited to the previous embodiments. 
         [0038]    Please refer to  FIG. 6A , which is an example of a moving device  34  in an apparatus for inspecting RFID tags according to one embodiment of the present invention. In the present embodiment, the moving device  34  comprises a guiding rail  340  and a carrier  341  installed on the guiding rail  340 . The carrier  341  comprises a holder  342  disposed thereon to carry the shelter  33  disposed thereon. The guiding rail  340  drives the carrier  341  to control the shelter  33  to move to a specific position to shield the RFID tags from communication with the reading device. Alternatively, the moving device can be driven by a screw bolt. Referring to  FIG. 6B , which is an example of a moving device in an apparatus for inspecting RFID tags according to another embodiment of the present invention, the moving device  34  comprises a screw bolt  345  coupled to a carrier  343 . The carrier  343  comprises a holder  344  disposed thereon to carry the shelter  33  disposed thereon. The screw bolt  345  drives the carrier  343  to move using a driving device (not shown) such as a motor to control the sheltering device  33  to move to a specific position to shield the RFID tag from communication with the reading device. The moving device  34  can be implemented using previous embodiments accompanied by  FIG. 6A  and  FIG. 6B  but is not limited thereto. 
         [0039]    Please refer to  FIG. 7 , which is a flow-chart showing the step of determining whether there is any malfunctional RFID tag of the method for inspecting RFID tags according to a second embodiment of the present invention. The present embodiment is different from the embodiment accompanied by  FIG. 3  wherein the RFID tags are shielded in a one-by-one manner. In the present embodiment, the RFID tags are shielded progressively. First, in Step  240   b , one of the RFID tags in the readable zone is shielded. Then in Step  241   b , the RFID tags in the readable zone are read. Afterwards, the Step  242   b  is performed to determine whether the number of readable RFID tags is reduced. The process goes to Step  243   b  if the number of readable RFID tags is not reduced. In Step  243   b , it is determined and recorded that the shielded RFID tag is malfunctional. Otherwise, if the number of readable RFID tags is reduced, the process goes to Step  244   b  to determine that the shielded RFID tag is functional. Afterwards, in Step  245   b , it is determined whether all the malfunctional RFID tags are found. The process goes to Step  25  if all the malfunctional RFID tags are found; otherwise, the process goes to Step  246   b  to progressively shield a next one and the previously shielded one(s) of the RFID tags in the readable zone. Then the process returns to Step  241   b  and repeats from Step  241   b  to  245   b  until all the malfunctional RFID tags are found. It is noted that, unlike the first embodiment wherein only one RFID tag is shielded, in the present embodiment, all the previously shielded RFID tags are also shielded. Therefore, in Step  242   b , whether the number of readable RFID tags is reduced is determined according to the number of read RFID tags after some RFID tags are progressively shielded, instead of the number of read RFID tags in Step  22  in  FIG. 2 . 
         [0040]    Please refer to  FIG. 8A  and  FIG. 8B  for schematic diagrams of an apparatus for inspecting RFID tags according to a second embodiment of the present invention. The apparatus  3  can be used to implement the method accompanied by  FIG. 7 . The apparatus  3  comprises a carriertape transportation device  30 , a reading device  32  and a sheltering device  35 . The carriertape transportation device  30  is capable of carrying a carriertape  31 . The carriertape  31  carries a plurality of RFID tags  311 . The carriertape transportation device  30  and the carriertape  31  are similar to those as previously described, and thus, descriptions thereof are not repeated. The reading device  32  is disposed on one side of the carriertape  31  and is capable of reading data in the RFID tags  311  on the carriertape  31  in a readable zone R. In one embodiment, a shielding plate  36  is disposed on each of two sides of the reading device  32  to limit the readable zone to avoid the reading device from reading the RFID tags outside the readable zone R. The sheltering device  35  is capable of shielding to limit the number of the RFID tags to be read by the reading device  35  and the sheltering device  35  is capable of varying a shielding area to determine the number of RFID tags. 
         [0041]    Hereinafter, the step of progressively shielding RFID tags in  FIG. 7  is described accompanied by  FIG. 8A . In the beginning, the sheltering device  35  shields a single RFID tag. Since there are still undetermined malfunctional RFID tags after Step  245   b  is performed, the process goes to Step  246   b  to progressively shield two RFID tags, as described in  FIG. 8B . Then, the process goes back to Step  241   b  so that the reading device  32  reads the RFID tags in the readable zone R. 
         [0042]    Then, it is determined whether the number of readable RFID tags is reduced compared to the number of the RFID tags when one RFID tag is shielded. If the number of readable RFID tags is reduced, it is determined that the newly shielded RFID tag is functional; otherwise, it is determined that the newly shielded RFID tag is malfunctional. Referring to  FIG. 8A  and  FIG. 8B , for example in  FIG. 8A , the number of read RFID tags is 10, which means that the RFID tag at the position (a) is functional. In  FIG. 8B , the number of read RFID tags is 10, which means that the newly shielded RFID tag at the position (b) is malfunctional. 
         [0043]    The sheltering device  35  capable of progressively shielding in  FIG. 8A  is implemented, as shown in  FIG. 9A , to comprise a plurality of shelters  350  capable of stretching to enlarge the shielding area so that the sheltering device controls the number of stretched shelters. In addition to  FIG. 9A , the sheltering device  35  can also be implemented, as shown in  FIG. 9B , to comprise a driving device comprising a linear guiding rail  351  and a carrier  352  installed on the linear guiding rail  351 . A large shelter  353  is disposed on the carrier  352  to be driven by the linear guiding rail  351  to move towards the readable zone R to progressively shield a next one and the previously shielded one(s) of the RFID tags by a linear movement. 
         [0044]    Please refer to  FIG. 10A  and  FIG. 10B , which are schematic diagrams of an apparatus for inspecting RFID tags according to a third embodiment of the present invention. In the present embodiment, the apparatus  4  comprises a carriertape transportation device  43 , a reading device  41  and a sheltering device  42 . The carriertape transportation device  43  is capable of performing a rotating movement  90  and carrying a disc carriertape  40  carrying a plurality of RFID tags  401 . 
         [0045]    The reading device  41  is disposed on one side of the disc carriertape  40 . The sheltering device  42  comprises a shelter  420  and a driving device  421 . The driving device  421  is capable of controlling the shelter  420  to move back and forth to shield the RFID tags  401  from communication with the reading device  41 . 
         [0046]    Basically, the operation of the apparatus  4  in the present embodiment is similar to that of the previously described two embodiments. In  FIG. 10B , however, since the carriertape  40  is disc-shaped, it is required that the carriertape transportation device  43  performs a rotating movement  90  to move a next un-inspected region to a position corresponding to the sheltering device  42  for inspection until all the malfunctional RFID tags are found after the sheltering device  42  has shielded a batch of three RFID tags. 
         [0047]    Please refer to  FIG. 11A  and  FIG. 11B , which are schematic diagrams of an apparatus for inspecting RFID tags according to a fourth embodiment of the present invention. In  FIG. 11A , a rectangular carriertape  44  is disposed on a carriertape transportation device  45 . The rectangular carriertape  44  carries a plurality of RFID tags  441 . The operation of the sheltering device  42  is similar to that of the previous embodiment in  FIG. 10A . Since the carriertape  44  is rectangular-shaped, it is required that the carriertape transportation device  45  performs a linear movement  91  to move a next un-inspected region to a position corresponding to the sheltering device  42  (as shown in  FIG. 1B ) for inspection until all the malfunctional RFID tags are found after the sheltering device  42  has shielded five RFID tags in a first row. 
         [0048]    According to the above discussion, it is apparent that the present invention discloses a method and an apparatus for inspecting radio frequency identification (RFID) tags by determining whether there is any malfunctional RFID tag and then determining where the malfunctional RFID tag is located using a way of shielding. Therefore, the present invention is novel, useful and non-obvious. 
         [0049]    Although this invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims.