RFID printer and antennas
View Patent ↗A shielded antenna system is provided for reading from and/or writing to an RFID transponder wherein the energy radiated from the antenna system has a narrow beam width so that only one RFID transponder in a record member along a web of record members, each having an RFID transponder, is read from and/or written to without affecting or being affected by any other RFID transponder along the web.
1. A printer for printing on a web of record members having RFID transponders disposed at spaced locations along the length of the web, comprising: a print head capable of printing .on a web, a read and/ or write loop antenna disposed upstream of the print head, wherein the loop antenna is in a generally rectangular configuration with the long dimension extending laterally of the web, the antenna being generally planar with spaced end edges along the long dimension, the printer having space for a web supply roll, the antenna being positioned so that the transponders pass into and out of alignment with one end edge of the antenna as the web passes from the supply roll to the print head.
2. A printer, comprising:
a print head disposed along a web path of travel of a web of RFID transponder-containing record members,
a microstrip antenna disposed adjacent the path and upstream of the print head, the microstrip antenna including a driven microstrip element and a ground plane,
an electrically conductive wall extending beyond the driven microstrip element toward the web path, the micros trip antenna being capable of radiating RF energy toward the web path, the wall blocking a portion of the RF energy from a transponder or transponders downstream of the wall, and
a shield disposed downstream of the print head to prevent the antenna from affecting or being effected by any RFID transponder at a location downstream of the shield.