Mechanism for attaching RFID tag, transfer device and transfer system using RFID tag
In a mechanism for attaching to a cart an RFID tag used for transmitting and receiving data to and from an RFID reader/writer, a holding pocket retains the RFID tag. The orientation of the pocket is kept constant in such a manner that a surface of the RFID tag from which data can be read highly accurately faces an antenna for the RFID reader/writer while keeping the distance between the RFID tag and the antenna within a certain range regardless of the transfer direction of the cart.
1. A mechanism for attaching to a transfer device an RFID tag used for transmitting and receiving data to and from an RFID reader or writer, comprising:
a retaining unit to retain the RFID tag; and
a holding unit to hold the retaining unit in such a manner that a surface of the RFID tag from which data can be read highly accurately faces an antenna of the RFID reader or writer while keeping a distance between the RFID tag and the antenna within a certain range regardless of a transfer direction of the transfer device, the holding unit including
a rotation member, the rotation member rotating the retaining unit in accordance with and when a change in the transfer direction occurs,
a projection member provided on the periphery of the rotation member and projects toward the center of the rotation member; and
an elastic member provided away from the rotation member and pushing the projection member, wherein:
when the retaining unit is rotated by the rotation member, the projection member escapes to a space away from the rotation member while applying a force to the elastic member, and
when the retaining unit passes through, said projection member returns to an original position by being pushed by an elastic force of the elastic member.
2. The mechanism for attaching to a transfer device an RFID tag according to claim 1 , wherein:
when the transfer direction of the transfer device is changed by one hundred and eighty degrees, the holding unit fixes the retaining unit at a position such that the distances to the antenna before and after the change of the transfer direction are the same.
3. The mechanism for attaching to a transfer device an RFID tag according to claim 1 , further comprising:
a post member extending from the transfer device; and
a wheel member attached to the post member and being directed toward a direction of movement of the transfer device, wherein:
the retaining unit comprises the post member, and the post member rotates in accordance with the direction of rotation of the wheel member.
4. The mechanism for attaching to a transfer device an RFID tag according to claim 1 , wherein:
the holding unit holds the retaining unit in such a manner that a surface of the RFID tag from which data can be read highly accurately is parallel to the antenna for the reader/writer provided in an orientation parallel to a floor.
5. A transfer device using an RFID tag for transmitting and receiving data to and from an RFID reader or writer, comprising:
a placing unit to place a transferred object;
a movement unit to move the placing-unit along a transfer rail;
a retaining unit to retain the RFID tag; and
a holding unit to hold the retaining unit in such a manner that a surface of the RFID tag from which data can be read highly accurately faces an antenna of the RFID reader or writer while keeping a distance between the RFID tag and the antenna within a certain range regardless of a transfer direction of the transfer device, the holding unit including
a rotation member, the rotation member rotating the retaining unit in accordance with and when a chance in the transfer direction occurs,
a projection member provided on the periphery of the rotation member and projects toward the center of the rotation member; and
an elastic member provided away from the rotation member and pushing the projection member, wherein:
when the retaining unit is rotated by the rotation member, the projection member escapes to a space away from the rotation member while applying a force to the elastic member, and
when the retaining unit passes through, said projection member returns to an original position by being pushed by an elastic force of the elastic member.
6. A transfer system using an RFID tag for transmitting and receiving data to and from an RFID reader or writer, comprising:
a transfer device including the RFID tag and transferring a transferred object;
a transfer rail to transfer the transfer device; and
an RFID reader or writer to perform communications with the RFID tag, wherein:
the transfer device comprises:
a placing unit to place the transferred object;
a movement unit to move the placing unit along a transfer rail;
a retaining unit to retain the RFID tag; and
a holding unit to hold the retaining unit in such a manner that a surface of the RFID tag from which data can be read highly accurately faces an antenna for the RFID reader or writer while keeping a distance between the RFID tag and the antenna within a certain range regardless of a transfer direction of the transfer device, the holding unit including
a rotation member, the rotation member rotating the retaining unit in accordance with the change in the transfer direction when the transfer direction of the transfer device is changed,
a projection member provided on the periphery of the rotation member and projects toward the center of the rotation member; and
an elastic member provided away from the rotation member and pushing the projection member, wherein:
when the retaining unit is rotated by the rotation member, the projection member escapes to a space away from the rotation member while applying a force to the elastic member, and
when the retaining unit passes through, said projection member returns to an original position by being pushed by an elastic force of the elastic member.