Patent Application
20070096882
1. Field of the Invention
The present invention relates to the testing and programming of radio frequency identification (RFID) tag devices.
2. Background Art
Radio frequency identification (RFID) tags are electronic devices that may be affixed to items whose presence is to be detected and/or monitored.
The presence of an RFID tag, and therefore the presence of the item to which the tag is affixed, may be checked and monitored by devices known as “readers.” Readers typically transmit radio frequency signals to which the tags respond. Each tag can store a unique identification number. The tags respond to the reader transmitted signals by providing their identification number, bit-by-bit, so that they can be identified.
Tags are typically programmed and tested for proper performance prior to being sold. Future demand for RFID tags is estimated to be for over a billion tags a year. Having an accurate high-speed programming and test system that can support such volume is extremely critical. Currently, programming and test systems that can rapidly and reliably handle large volumes of tags do not exist. Current systems are extremely difficult to control and are reaching their limits in terms of the volume of tags that can be reliably programmed and tested.
Such systems can suffer from a variety of problems. For example, systems using radiated test signals sometimes unintentionally read adjacent tags, and thus have difficulty identifying a specific “bad” tag from a group of tags.
Furthermore, tags are susceptible to tampering by unauthorized sources. For example, an unauthorized source may attempt to read tags, re-program tags, or even “kill” tags, surreptitiously, by communicating with the tags.
Thus, what is needed are RFID tag programming and testing schemes which can handle very large volumes of tags, and can program and test the tags rapidly, in a reliable, secure, and repeatable fashion.
Methods, systems, and apparatuses for selecting radio frequency identification (RFID) tags are described. In aspects of the present invention, a desired tag may be selected for interaction from a group of tags. The selection of a tag enables the interrogating, programming, testing, and/or other processing or operating on the tag, without interference from others of the nearby tags.
In an example aspect, a radio frequency identification (RFID) tag includes a substrate, an antenna on the substrate, an integrated circuit (IC) die mounted to the substrate, and a sensor that when stimulated enables a function of the tag.
In a further example aspect, a tag selector stimulates a sensor of the tag to enable a tag. A tag processor interacts with the enabled tag. The tag processor can test, program, and/or otherwise interact with the tag, while enabled. In this manner large numbers of tags can be interacted with in close proximity, such as during their manufacture in a web format, because the tag selector dictates which tag(s) are enabled at any one time.
These and other advantages and features will become readily apparent in view of the following detailed description of the invention. Note that the Summary and Abstract sections may set forth one or more, but not all exemplary embodiments of the present invention as contemplated by the inventor(s).
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
The present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
Introduction
The present invention relates to the testing of radio frequency identification (RFID) tags. According to embodiments of the present invention, a function of a tag is enabled by stimulation of a sensor of the tag. The enabled tag can be interacted with. For example, the tag can be tested, programmed, killed, interrogated, or otherwise processed or operated on. Other surrounding tags have not been stimulated, and thus do not respond to the attempts to interact with the tag. In this manner large numbers of tags in close proximity can be processed, such as during their manufacture in a web format, because only a selected tag is enabled at any one time.
It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
Tag Selection and Interaction Embodiments
The present invention is applicable to any type of RFID tag.
Volume production of RFID tags, such as tag 100, is typically accomplished on a printing web based system. For example, in such a system, the tags are assembled in a web of substrates, which may be a sheet of substrates, a continuous roll of substrates, or other grouping of substrates. For instance,
On a web, such as web 200, RFID tags are typically assembled/positioned as close to each other as possible to maximize throughput, thus making the process of reading, programming, killing, and/or testing individual tags difficult. For example, it may be desired to program a tag, such as writing an identification number and/or other data to the tag. Furthermore, it may be desired to run a test algorithm for the tag to test its operation. Because of the close spacing in web 200, it is very difficult to localize a radiated (e.g., radio frequency) reader field to excite only one tag.
According to embodiments of the present invention, a tag selection configuration is used to select individual tags, even for tags positioned in close quarters, so that the selected tags can be interrogated, tested, programmed, killed, or otherwise interacted with, in a more reliable, secure, and repeatable fashion than in conventional schemes. In embodiments of the present invention, a tag selector interacts with a tag by stimulating a sensor of the tag.
Embodiments of the present invention are applicable to interacting with tags 100 in web 200. Tags may also be interacted with in other environments. In embodiments, tags may be interacted with in tag assembly/manufacture environments, in warehouse environments, in retail environments, etc.
For example,
Example operation of system 300 is described with respect to
Flowchart 400 begins with step 402. In step 402, a tag is received having a sensor. For example, the tag is tag 100 shown in
In step 404, the sensor of the tag is stimulated to enable a function of the tag. For example, as shown in
In step 406, the enabled function of the tag is interacted with. In other words, the functionality of tag 100 enabled by stimulus of sensor 306, may be interacted with, including partial or full functionality of the tag. As shown in
For example, as shown in
In another example, step 406 may include programming the tag, as in step 406b. Thus, for example, tag processor 304 may include functionality to write an identification number and/or other data into storage 702 of tag 100. Thus, in an embodiment, tag processor 304 may include a programming module, having the hardware, software, and/or firmware necessary to program tags.
In another example, step 406 may include testing the tag, as shown in step 406c. Thus, for example, tag processor 304 may include functionality to perform a partial or full diagnostic test of tag 100. Thus, in an embodiment, tag processor 304 may include a test module, having the hardware, software, and/or firmware necessary to test tags.
In another example, step 406 may include killing the tag. For example, in step 404, tag selector 302 stimulates sensor 306, such that sensor 306 enables a “kill” functionality of tag 100. When the kill functionality is enabled, tag 100 may be killed (e.g., be made unable to be communicated with) by a kill signal. For example, when an item attaching tag 100 is sold in a retail environment, it may be desired to kill tag 100 so that it is no longer operational. This may be done to address privacy concerns, so that tag 100 cannot be later read. Thus, at a checkout area, for example, tag 100 may be brought near tag selector 302, to enable the kill functionality. Then, before the item leaves the store, a kill signal source (e.g., tag processor 304) can be used to kill tag 100 that has the kill functionality enabled. In this manner, tags in the vicinity that are not desired to be killed are not accidentally killed by the kill signal source, and only tags associated with items that have been sold are killed.
In another example, step 404 may include enabling a communication functionality of the tag, such as after a kill signal source has previously killed the tag. Thus, tag selector 302 stimulates sensor 306 to enable a killed tag 100 to communicate. In this manner, a previously killed tag 100 could be re-used. For example, in step 406, the tag could be re-programmed, etc., in a warehouse, by a person at home who purchased an item having the killed tag attached thereto, etc.
In an embodiment, once the tag selector stimulus is no longer applied to the tag sensor, the function of the tag is no longer enabled. Subsequently, a next tag can be enabled through application of the stimulus. Furthermore, an entity, such as tag processor 304, can interact with the enabled next tag. This interaction with the next tag can be performed without interference from the prior tag, which is no longer enabled.
Alternatively, in an embodiment, after a tag selector stimulus is applied to a tag, the tag is changed to and remains in the enabled state. Thus, in this alternative embodiment, the transition of the tag to the enabled state is permanent. In alternative to this embodiment, a second application of the stimulus can be used to disable the tag once again. Thus, in this embodiment, the tag selector stimulus can be used to toggle a tag between enabled and disabled states. For example, in a possible application, the tag selector stimulus could be applied to each tag twice, to temporarily enable and disable each tag in a web of tags for interaction therewith (e.g., programming, testing, killing, and/or communicating), and subsequently the tag selector stimulus could be applied a third time to each tag to permanently enable the tags to be used in the field once they leave the interaction station. Other mechanisms may be used to enable tags leaving the interaction station for operation in the field, as would be known to persons skilled in the relevant art(s) from the teachings herein. For example, in an embodiment, after testing, programming, etc., the sensor functionality of the tags could be killed by a kill signal or stimulus, to leave the tags permanently in the enabled state.
Thus, tag processor 304 can interact with enabled functions of tag 100 in the manners described above, elsewhere herein, and in any other way. Tag selector 302 and tag processor 304 each include software, hardware, and/or firmware, or any combination thereof, for selecting and interacting with tags, respectively. Tag selector 302 and tag processor 304 may be incorporated together into a computer system. Tag selector 302 and/or tag processor 304 can further include one or more storage devices for storing information regarding system 300 and tags being interacted with, including memory components, disc-based storage, magnetic storage devices, optical storage, etc. Furthermore, tag selector 302 and/or tag processor 304 can together or separately include a user interface, such as including a keyboard, display, graphical user interface (GUI), pointing device, and/or other visual and/or audio indicators, for a user to interact with tag selector 302 and/or tag processor 304 as needed.
In embodiments, tag processor 304 generates one or more interrogation signals or test signals to test tags. For example, test controller 302 may communicate with a tag according to any RFID communication protocol. Tag processor 304 may generate the signal(s) according to one or more interrogation/read protocols, as would be known to persons skilled in the relevant art(s), to read/communicate with tags under test. Example such protocols include binary protocols, tree traversal protocols, slotted aloha protocols, and those required by the following standards: Class 0; Class 1; and EPC Gen 2. Any future developed communication algorithms/protocols are also within the scope and spirit of the present invention.
As described above, the tag processors described herein can include elements of conventional RFID readers. For example, depending on the particular application, a tag processor may incorporate one or more antennas, power controls, and read and write capabilities of an RFID reader, to conduct the interrogation and/or testing of tags. For instance, example conventional readers having features that are applicable to the embodiments of the present invention include AR400 and XR400 readers sold by Symbol Technologies of Holtsville, N.Y. The AR400 and XR400 are example 4-port readers that may be used in a “multi-channel” testing configuration, such as shown in
An enabled tag 100 processes tag interaction signal 310 received from tag processor 304. The enabled tag 100 generates a corresponding response if appropriate (e.g., when being tested and/or interrogated). Tag processor 304 evaluates the response of tag 100 to determine whether the enabled function responded properly (if a response is expected).
For example, in a test interaction, tag processor 304 may evaluate the response of tag 100 to determine whether tag 100 is operating properly. For instance, the test signal(s) of tag processor 304 may have interrogated tag 100 for its identification number. Test controller 302 evaluates whether tag 100 properly responded with its identification number. In further embodiments, data other than the identification number can be read from tag 100, to test other data, storage elements, and/or features of tag 100. In embodiments, any type of test may be performed, to test any feature, parameter, characteristic, etc., of tag 100.
If during an example test, the identification number is properly received from tag 100 (and/or the tag otherwise responds properly), tag processor 304 determines that tag 100 has passed the test, and tag 100 can proceed accordingly. For example, in an embodiment, tag processor 304 may provide an indication that tag 100 passed the test by illuminating an indicator light, by displaying test result information on a graphical display, by storing test result information in storage, and/or by taking other action (or no action).
If the identification number is improperly received (and/or the tag otherwise responds improperly), tag processor 304 determines that tag 100 did not pass the test, and may not be functioning properly. For example, an improperly functioning tag may generate a response that is incorrect (i.e., is not the response expected from the tag for the particular test being performed, including a non-response). In such a situation, tag processor 304 may provide an indication that tag 100 failed the test by marking tag 100 as defective, by illuminating an indicator light, by displaying test result information on a graphical display, by storing the test result information in storage, and/or by taking other action. In this manner, the failed tag 100 can subsequently be repaired, disposed, or recycled.
In embodiments, any number of interactions can be performed with a particular tag, as long as the tag is enabled. Furthermore, in embodiments, multiple tags received in parallel may be interacted with according to embodiments. For example,
In embodiments, system 800 may be incorporated into a tag assembly line (TAL), which may be a partially or fully automated assembly line. In the example of
Once tags 100 have been assembled in web 200 to the extent that they are functional, they can be interacted with using system 800, for programming, test, etc. Computer 802 is coupled through a communications link 810 to motor controller 804. Computer 802 provides control signals to control operation of motor controller 804 over communications link 810, and may receive feedback from motor controller 804 over communications link 810, if appropriate for a particular application. Motor controller 804 causes roll 812 and/or further wheels and/or spools coupled to web 200 to advance web 200.
In the embodiment of
A single width row of selector elements 808 can be present to operate on a row of tags 100 of web 200, or a two-dimensional array of selector elements 808 can be present in system 800, to operate on a multiple rows of tags 100 web 200. Web 200 can be periodically or continuously advanced, such that subsequent rows of tags can be operated on in a similar fashion by selector elements 808. This process can continue until interaction with all the tags of web 200 is complete.
Alternatively, a single selector element 808 may be present in system 800. In such an embodiment, the single selector element 808 may be directed (e.g., aimed) or moved (e.g., by selector mount 806) as needed to operate on tags 100 at different positions on web 200. For example, in a laser selector embodiment, a scanning laser could be used (e.g., to provide a heat pulse), enabling tags one at a time on web 200 by being sequentially aimed at the tags.
Computer 802 is coupled to tag processor 304 through a communications link 830. Tag processor 304 is configured to provide tag interaction signal 310, under control of computer 802, to interact with a particular tag 100 of web 200 that is enabled by a sensor element 308. If appropriate, tag processor 304 is configured to receive responses from the particular tag 100 being interacted with. Tag processor 304 may radiate tag interaction signal 310 to a tag through the air, as shown in
Computer 802 uses selector elements 808 to sequentially stimulate each tag 100 of web 200, one at a time, to sequentially enable a function of each tag 100. Tag processor 304 sequentially interacts with each stimulated tag 100 to interact with the tag function while enabled. In this manner, system 800 allows separate interaction with each of tags 100 of web 200.
Once tags 100 are interacted with (e.g., programmed and tested), further processing may be performed on tags 100, including processing tags 100 into label format, singulation of web 200 into separate tags, removal of failed tags, etc.
Note that selector mount 806 of
System 800 is shown for illustrative purposes, and not for purposes of limitation. Embodiments of the present invention may be implemented in a variety of systems. For example, label printers exist that print a bar code label, while programming a RFID tag embedded in the label. In such an application, the label printer (hand-held or otherwise) may include a selector element 808, such as a heating head, that is pulsed to enable programming of the tag of a label currently being spooled and printed. Thus, a label currently being spooled over a test head of the label printer can be tested without impacting other tags on the label spool. Further systems and applications for selection and interaction with tags will become known to persons skilled in the relevant art(s) from the teachings herein.
As described above, a variety of types of sensors 306 may be present in tags 100. Thus, various corresponding types of selector elements 808 may be used to produce a corresponding tag sensor stimulus 308 to stimulate the sensors.
Note that contact members 1308 and 1408, when present, may include a spring and/or other shock-absorption mechanism, to prevent damage to tag 100 when they make contact therewith.
In embodiments, the tag selection techniques described herein allow interaction with tags in an independent and sequential manner. The tag selection techniques also reduce the possibility of tags being read, re-programmed, or killed by unauthorized sources, because interaction with the tags requires application of the tag selector stimulus.
Conclusion
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
