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Linear Motion Programming System for BiStatix® Tags on a High-Speed Printing Web

IP.com Disclosure Number: IPCOM000005577D
Original Publication Date: 2001-Oct-16
Included in the Prior Art Database: 2001-Oct-16
Document File: 5 page(s) / 162K

Publishing Venue

Motorola

Related People

James G. Quaderer: AUTHOR

Abstract

Linear Motion Programming System for BiStatix® Tags on a High-Speed Printing Web

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Linear Motion Programming System for BiStatix® Tags on a High-Speed Printing Web

By James G. Quaderer

                    Conventional RFID cards inductively couple to readers via embedded resonant copper coils within the tags.  BiStatix systems, on the other hand, capacitively couple to readers via capacitive coupling to achieve similar performance.  BiStatix card antennas are composed of extremely low cost conductive ink as opposed to an expensive and bulky copper coils.

 
 

Figure 1

 
 

Figure 1 shows the construction of a typical BiStatix tag 1.  The interposer 103 contains an RFID integrated circuit which couples to antenna electrodes 101 and 102.  BiStatix electrodes 101 and 102 are usually composed of conductive ink.

Printed materials, including BiStatix cards, are commonly manufactured on long continuous strips of paper called webs.  It is common for webs to move at speeds above 200 feet per minute in modern printing facilities.  Completed BiStatix cards on the web must be programmed and tested at rates of 200 feet per minute to maintain efficient printing operations.  Conventional methods of testing inductive cards, which would require that the web be indexed (started and stopped for each individual card) over an RF test head, would be cumbersome and far less economical than a continuously moving-web test process.

Rolling drum-type electrodes may be used to maintain coupling between the BiStatix card and the test equipment with the constraint that consistent electrical coupling be maintained to the drum.  This coupling may be achieved by a variety of means, for example, conductive brushes, conductive rollers, or capacitively-coupled plates.  The rolling drum-type electrodes, unfortunately, are moving parts which require additional maintenance over stationary test electrodes.  In addition, whenever the design of the card electrodes change, the electrodes on the drum will need to be physically modified to match their card counterparts – this requires some technical proficiency and results in additional machine downtime.

Rolling belt-type electrodes have the same design and use concerns as rolling drum-type electrodes but with more moving parts.

Linear Electrode Arrays

                    Stationary linear electrode arrays require an insignificant amount maintenance.  When many small, stationary electrodes are used to couple to only one card, the electrode design need not be changed whenever the card is redesigned – simply the number of electrodes associated with that card design needs to be changed.  When the card moves across a linear array of small electrodes, the electrodes in the array may be switched in and out to couple to that specific card.  When many cards are placed in close proximity on a high-speed web, multiple groups of small electrodes may be switched in and out to couple to a plurality of cards simultaneously.  The clock rate of the linear electrode array switches may be strobed by a switch or an opto-sensor which senses the cards as they move on the web so that as the speed of th...