Communications: electrical – Selective – Interrogation response
Reexamination Certificate
1998-09-10
2002-01-29
Zimmerman, Brian (Department: 2635)
Communications: electrical
Selective
Interrogation response
C343S841000, C343S873000, C307S091000, C340S572700
Reexamination Certificate
active
06342830
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a system for transferring electronic information using multiple electronic tags. More particularly, the present invention relates to object attachable radiofrequency electronic tags and tag readers connected to a computer network.
BACKGROUND AND SUMMARY OF THE INVENTION
Tagging items with barcodes or symbols that facilitate optical character recognition has long been used to identify and track product inventories, baggage, paper checks, or other movable items susceptible to misplacement or loss. Unfortunately, such optically perceptible tags must remain visible for identification, and can be easily rendered unreadable by surface marks or other damage.
To improve tracking reliability, attempts have been made to use radiofrequency based electronic tags. Such tags typically have a semiconductor memory for data storage, processing logic, and a small antenna for broadcasting data, all embedded in rugged epoxy, thermoplastic, or other suitable plastic containers. Data storage capacity typically ranges from a few bits to many kilobits, with 64 bits being typical. Tags can include read only memory (ROM), electrically programmable or erasable (EPROM and EEPROM), or even flash memory. An electronic tag can be powered by a long lasting small battery, photovoltaic power, thermal convertor, inductive power converter that relies on externally applied electromagnetic energy, or any other suitable power supply.
Unfortunately, since such electronic tags broadcast information when powered, use of large numbers of electronic tags in close physical proximity is difficult. For example, if multiple electronic tags are situated within a few centimeters of each other, their overlapping data broadcasts could interfere with each other, making it difficult to determine tag identity. Such problems have generally limited electronic tag placement by requiring only one tag per object, with each object being well separated from each other during data transfer. This requirement has limited use of electronic tags in an office environment, where large numbers of tags could be profitably used for tracking papers, files, or other printed material.
In the modern office environment, the management of paper documents is not well coordinated with the management of their electronic counterparts. If an electronic tag is attached to a physical document, a user can access some associated virtual representation (e.g. an ASCII text file) by placing it near an augmented computer equipped with a tag reader. The resulting system is a powerful tool for maintaining a bridge between physical and virtual representations of documents, or, in general, for augmenting physical objects with virtual associations. Advantageously, the present system can be used to track multiple tagged documents in close proximity, or to allow performance of various selected services (e.g. printing, e-mailing, discarding electronic copies, opening electronic applications)
The present invention meets these requirements by providing a system for identifying multiple electronic tags that includes a plurality of electronic tags attachable to a single object, each electronic tag having a non-overlapping readable region, and each electronic tag having a unique identifier. One or more electronic tag readers are configured to read the unique identifier of each electronic tag within the non-overlapping readable region, and a computing system is connected to the electronic tag reader to provide digital services in response to reading the unique identifier of each electronic tag. In certain embodiments, the electronic tags can have integral sensor systems that detect, for example, light, location, acceleration, or other physical properties, allowing provision of particular digital services related to the sensed properties.
Such a system is particularly useful for multiple tagging of substantially threedimensional objects (solids) or two-dimensional objects (sheets) with large numbers of distinct electronic tags. For example, a multifaced solid such as a polygon can have each face, edge, or vertex equipped with a unique electronic tag that invokes a digital service (or provides parameters for enabled digital services). Various symbolic indicia such as text, graphics (pictures or line drawings), color codings, texture codings, etc. can be used to assist a user in associating a particular tag with a digital service.
The foregoing electronic tags can be read by tag readers attached to desktop computers, or in certain embodiments, by tag readers integral or closely attached to portable or hand holdable computers. Such portable computers can also support wireless network transceivers for communication with a computer network, extending the range of supported digital services.
In operation, at least one electronic identification tag is affixed to each physical item that is associated with digital services. These tags can be small radio frequency transponders comprised of an integrated circuit, containing a unique user accessible 39-bit identification number. A small coil inductively powers the tag, and an antenna is used to broadcast the identification number. In certain embodiments, the antenna can be separate from the coil, or alternatively, a dual-use inductive power coil/antenna coil can be used.
A tag reader that includes transmitter and receiver components is affixed to a computational device such as a hand held computer. The tag reader transmits a pulse that momentarily energizes the tag through its coil until it has sufficient power for transient transmission of its identification number. The communication between tag and tag reader only occurs when both are proximate, with an actual distance varying based on size of the antenna attached to the tag and to the transmitter, from a distance of a few inches to that of several feet. Once the identification number (transmitted serially) is received, the tag reader passes this on to the computer system as an ASCII string, via a serial RS-232 output or some other suitable connection, while simultaneously providing user feedback to confirm reading of the tag. User feedback can be visual (e.g. blinking or turning on an LED status light, text based or iconic display presentations), auditory (e.g. an audible buzz or beep), tactile (e.g. a button being raised or a perceptible structure rotation), or combinations of the foregoing.
Upon receipt of the identification number, a computer based application program interprets the identification input string, determines the current application context, and provides appropriate digital services. For example, an ASCII database that maps identification numbers to one or more digital services can be used. One common action is a program, {identification number} pair that invokes the identified program on the associated identification number. If the received identification number has not been previously registered, i.e. associated with an action in the ASCII database, the user can be prompted to enter an action(s) and any associated parameters via a dialog box. Network and server connectivity is provided by a separate wireless radiofrequency or infrared networking system. If the program or the file to be retrieved reside on the network, filenames that are independent of the particular sensing computer can be used.
In addition to an identification number, certain embodiments of tags in accordance with the present invention can convey small amounts of modifiable data (maintained, e.g., in flash memory). For example, data provided by sensors embedded or attached to the tag can be used to detect folding, twisting, or bending of the tagged object. Alternatively, a number of accelerometers that sense relative spatial information; gyroscopic, radio or infrared positional sensors for determining absolute position; and various thermal or photosensors that respectively detect temperature and light level changes can provide sensed data values for later transmission by the tag. Intentional or unintentional modifications detected by one
Fishkin Kenneth P.
Gujar Anuj Uday
Harrison Beverly L.
Irish Wesley R.
Want Roy
Oliff & Berridg,e PLC
Xerox Corporation
Zimmerman Brian
LandOfFree
Controlled shielding of electronic tags does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controlled shielding of electronic tags, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlled shielding of electronic tags will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2863188