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Description  |
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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 three-dimensional 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 s 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 or more of these
sensor systems, taken in conjunction with the particular tag presented to the tag reader, can provide the basis for a powerful user interface scheme.
As those skilled in the art will appreciate, each identification number or sensed data value that is read (sensed) by the tag can be labeled as a "senseme", with a particular digital service or attribute being associated with each senseme.
Although the wide variety of easily distinguishable sensemes (e.g. identification numbers) would alone provide a powerful user interface to a computer, the present invention further extends the flexibility of the senseme based user interface by
supporting computer control based on a multiple senseme input, with temporally synchronous (or overlapping asynchronous) tuples of one or more sensemes (e.g. particular identification numbers and sensed states) being read by the tag reader. Single and
multiple sensemes can in turn be extended by participation in a "sentence". A sentence is defined as a sequence of one or more temporally disjoint sensemes or senseme tuples. The sentence level allows definition of a input grammar by appropriate choice
of senseme sequence, and corollary rules governing, for example, use of active verb-like sensemes (e.g. "print"), naming noun-like sensemes (e.g. DOC1.TXT), or connectors (e.g. AND).
In effect, the present invention provides a method for transferring information from a tagged object with optional sensors to a tag reader connected computer. The method comprises the steps of manipulating one or more tags and optional tag
sensors to provide a first senseme input (that includes the tag identification number) to the computer, with the first senseme input normally triggering a first default action by the computer. The tagged object may also be manipulated to provide a
second senseme input (again including a tag identification number) to the computer, with the second senseme input converting the normally triggered first default action to a second action. The first and second sensemes (and any subsequent sensemes)
together form a sentence that can be interpreted as a command to implement a computer controlled action, whether it be to open and print a particular electronic document, unlock an electronically controlled door in response to a tag conveyed personal
identification number, display a graphical image on a computer display, or begin logging on to a computer network. In operation, for example, the sentence "establish authorization, open a file, and print the file to printer number 3" can involve the
sequential steps of reading a first tag embedded in a picture identification card to establish user identification, immediately presenting a second tag clipped to a paper document to specify a related electronic document and finally presenting a three
dimensional token that appears like a small printer with an embedded third tag and pressure sensor that initiates printing of the previously specified document at printer number 3 after pressure sensors electrically connected to the tag are squeezed
three times. The foregoing operation conveniently distinguishes particular electronic documents, and allows a user to select particular printers, (e.g. with printer 1 requiring one sensed squeeze and printer 2 requiring two sensed squeezes) without
requiring visual displays or complex input commands.
Utility of the foregoing system can be extended by selective shielding of the electronic tag. Shielding can be used to arbitrarily limit the readable range or provide strong directional reading properties for the electronic tag, a particularly
useful feature when large numbers of electronic tags are positioned near each other. According to the present invention, an electronic tag including a processor, a readable memory for holding an identification number connected to the processor, an
antenna connected to the processor for radiofrequency broadcasting of the identification number, and a power supply for powering the antenna to broadcast the identification number is provided with an electromagnetic shield positioned near the antenna for
reducing broadcasting range of the antenna. The shield can, for example, be metallic wire or sheeting positioned at least partially around or near the antenna, or metal lined cavities into which the electronic tag is attached. Such shields in
accordance with the present invention reduce reading range and can limit reading of the tag to specific directions. For example, electronic tags can be partially surrounded with shields to limit readable electromagnetic radiation to a direction
substantially normal to the surface of an object to which the tag is attached. Such shields would allow large numbers of electronic tags to be closely spaced on an object, since interfering lateral electromagnetic radiation from adjacent tags would be
inhibited.
In certain embodiments, the electromagnetic shield is movable between a first substantially non-blocking position and a second blocking position that respectively unblocks and blocks antenna broadcast. The movable electromagnetic shield can be s
biased to remain in its first substantially non-blocking position to allow antenna broadcast, or alternatively biased to remain in its second blocking position to block antenna broadcast. Advantageously, a user movable shield also permits use of the
electronic tag as a user defined communication channel for transmitting small amounts of information. If an electronic tag having a transmitted identification number is controllably shielding and deshielding to provide a user defined time series of
readable and non-readable intervals for the transmitted identification number, the consequent user defined time series of readable and non-readable intervals for the transmitted identification number can be interpreted as bit-wise communication
associatable with the transmitted identification number. In effect, a user could send bit codes by intermittently interrupting reading of the electronic tag (or alternatively, by intermittently allowing reading of the electronic tag). Such small
amounts of user defined and transmitted information can be used to parameterize digital services associated with the transmitted identification number, or can even be used as personal identification numbers or verifiers to initiate triggering of a
digital service in response to reading an electronic tag. For example, a tag reader can be configured to launch an application only after receipt of two pulses (clicks) of a particular identification number. Such a mechanism reduces inadvertent or
unwanted triggering of a digital service ordinarily provided in response to reading an electronic tag.
In addition to selective shielding, the present invention provides for selective enablement and disablement of electronic tags. This is yet another mechanism that eases problems associated with use of large numbers of closely placed electronic
tags, and also allows for some limited user defined communication. An electronic tag having a processor, a readable memory for holding an identification number connected to the processor, an antenna connected to the processor for radiofrequency
broadcasting of the identification number, a power supply for powering the antenna to broadcast the identification number, is also provided with an interconnect switch for interconnecting at least two members selected from a set defined by the processor,
readable memory, antenna, and power supply. The interconnect switch can be biased to remain normally open, preventing broadcast of the identification number, or alternatively, can be biased to remain normally closed, allowing broadcast of the
identification number.
As will be appreciated, the interconnect switch can be connected between the antenna and one of the processor and the power supply, with opening or closure being controlled by a user that opens or closes electrical contacts in the interconnect
switch (using any conventional button, contact switch, electrical switch, or other conventional switch known to those skilled in the art). In certain embodiments, a sensor can be connected to the processor, and the interconnect switch is alternately
opened and closed in response sensor data provided by the sensor. For example, an electronic tag can be equipped with an accelerometer capable of signaling when the tag is nudged or shaken. Normally, the tag remains disabled with its interconnect
switch open. If the tag is moved, shaken, or nudged, the accelerometer senses the transient accelerations and sends a signal to the interconnect switch to close, allowing the electronic tag to broadcast its identification number. A second shaking
reverses the foregoing, causing the sensor to signal the interconnect switch to open and break the antenna/power-supply connection (for example), disabling the electronic tag. Sensor systems responding to heat, light, sound, force, or any suitable
effect can be employed in the present invention.
As noted previously in connection with movable shields, user defined enablement or disablement of the electronic tags can be used for low bit rate communications directed by a user. Controllably switching an interconnect switch of an electronic
tag having a transmittable identification number provides a user defined time series of readable and non-readable intervals for the transmitted identification number. This user defined time series of readable and non-readable interval for the
transmitted identification number can be readily interpreted as bit-wise communication associatable with the transmitted identification number.
Additional functions, objects, advantages, and features of the present invention will become apparent from consideration of the following description and drawings of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a system for identifying multiple electronic tags and providing various digital services in response to sequential presentation of electronic tags to an electronic tag reader;
FIG. 2 is an illustration of a hand holdable computer having an attached electronic tag reader;
FIG. 3 is a schematic illustration showing various components of a conjoined hand holdable computer and attached electronic tag reader such as shown in FIG. 2;
FIG. 4 is a schematic illustration of a user employing a conjoined hand holdable computer and attached electronic tag reader such as shown in FIG. 2 to access an identification number of an electronic tag affixed to a two dimensional wall mounted
poster, and wirelessly transfer that information to a computer network for accessing related electronic documents;
FIG. 5 illustrates a networked printer capable of printing documents identified by an electronic tag, and of associating newly printed documents with a unique electronic tag dispensed or attached by the printer;
FIGS. 6 and 7 taken together are a flow chart that together illustrates various steps in interpreting signals from electronic tags and launching appropriate digital services;
FIG. 8 is an exemplary illustration of a movable disk shaped shield rotatable relative to a disk having several attached electronic tags;
FIG. 9 is an example of a slidable shield;
FIGS. 10, 11, and 12 are an example of a clickable shield that can be used to send low bit rate user information by selective shielding and deshielding of an electronic tag;
FIG. 13 is a schematic illustration of elements of an electronic tag controllably interconnected by an interconnect module to allow selective enablement or disablement of the electronic tag;
FIG. 14 is an example of a selectively enabled electronic tag, with a processor/memory unit normally biased to be separated from power converter antenna unit; and
FIG. 15 is a graph schematically illustrating a user defined bit signaling time series of readable and non-readable intervals for a transmitted identification number from an electronic tag.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a system 10 for identifying multiple electronic tags 32, 42, 44, and 46 (each tag generally having a unique electronically readable identification number) and providing various digital services in response to
presentation of those electronic tags to electronic tag readers 20, 26, or 28. To access the digital services, the electronic tag reader 20 (or electronic tag reader 26 and 28) is connected to a computer system 12, which further includes a local
computer 14, database servers 16, and networked computers 18. In this illustrated embodiment of the present invention, electronic tag 32 is clipped to a paper document 30, while electronic tags 42, 44, and 46 are mounted respectively on faces 52, 54,
and 56 of a cube shaped polygon 50. Determining what digital service is invoked is aided by various textual, graphical, or symbolic indicators 62, 64, and 66 respectively located near each electronic tag 42, 44, and 46. The electronic Is tags 32 or 42,
44, and 46 are brought near one or more of the tag readers, query/response signals 22 and 24 are passed between the electronic tags and the tag reader, and the identification number of the read electronic tag is passed to the computer system.
As those skilled in the art will appreciate, electronic tags can be attached permanently or temporarily to various objects, including but not limited to the paper document 30, polygon 50, books, magazines, posters, notecards, printed
advertisements, walls, floors, ceilings, furniture, electronic devices, portable computers, containers, cardboard boxes, clothing, or any other suitable object. Electronic tags can be permanently attached by embedment in objects, adhesive attachment to
an object's surface, fixation by staples, or by mating to an object by any other suitable attachment mechanism. Temporary fixation of electronic tags to objects can be enabled through the use of object attachable clips, snaps, or ties (e.g. a paper clip
with attached electronic tag, a rubber band or loop of string with an attached electronic tag), simple resting dispersal (e.g. throwing an electronic tag to rest upon a floor), insertion into a slot or receptacle, or any other suitable temporary
attachment mechanism that advantageously eases reuse of an electronic tag by allowing successive association with various attached objects.
In FIG. 1, an object having more than one attached tag is indicated as polygon 50. The polygon 50 has multiple electronic tags 42, 44, and 46, one respectively mounted on each face 52, 54, and 56. The polygon 50 can be rotated to substantially
present one face and its corresponding face center mounted electronic tag to the reader 20. As will be appreciated, electronic tags can be mounted anywhere on the polygon 50, including on its edges, on its vertices, in a random or semirandom
distribution, or symmetrically distributed about the polygon and centered on each face, as illustrated. As will be understood, use of such polygons (e.g. cubes, tetrahedrons, rhombic dodecahedrons, two sided planar solids, or related shapes), in
conjunction with face centered attachment, can take advantage of passive shielding of the faces to limit simultaneous readings of multiple electronic tags. Although the polygon 50 is indicated as a unitary solid object, various other shapes are
contemplated to be within the scope of the present invention. For example, the overall shape may be similar to various rectangular prisms, or can be spheroidal, ellipsoidal, toroidal, planar, irregular, or even malleable enough to allow user definition
of object shape. In addition, multiple cooperating shape elements fitted with electronic tags are contemplated, including conventional designs that permit interlocking of multiple shape elements, using ball and socket, a lock and key, slidable or
rotatable interlocked components, chains, or any other linked object.
Electronic tags suitable for attachment to such foregoing objects in accordance with the present invention generally broadcast a unique identification number and optional data at various selected radiofrequencies. The identification number can
be user assigned at electronic tag activation, user modifiable by software command, or fixed by an electronic tag manufacturer, depending on the particular memory system employed. In certain embodiments, infrared, ultrasonic, or other suitable data
transfer systems may be used alone or in combination with radiofrequency tags to transmit unique identification numbers or associated data. The electronic tags can be inductively powered by external electromagnetic coils, powered by internal batteries,
powered by photovoltaic cells, powered by trickle currents from household current when available, or any other suitable power mechanism. Broadcast of the identification number and/or data can be continuous, intermittent, in response to external status
inquiries, at random intervals, or in response to local powering of the electronic tag.
The electronic tag 46 can be optionally attached to a sensor 47. Various sensor modes can supported, including absolute or relative positional information as determined by gyroscopic sensors, accelerometers, or acoustic or infrared ranging
techniques. Environmental sensors, including conventional light, image, thermal, electromagnetic, vibratory, or acoustic sensors can also be present. Depending on the desired application, environmental or positional sensors such as those incorporating
differential GPS positioning, image analysis or recognition, acoustic or voice identification, or differential thermal sensors can be used. Sensors may include accelerometers, compressional or tensional strain sensors, or alternatively, embedded or
attached positional sensors. For certain applications, continuous sensors (e.g. bilayer sheets of capacitance sensors) may be employed. One particularly useful continuous sensor type uses multiple capacitance or resistance strips, with deformation
pressure resulting in a positionally localizable analog signal proportional to the applied deformation pressure. Various sensor types can be used, including simple capacitance sensors, resistive strain sensors, analog or digital pressure switches,
inductive sensors, or even fluid flow sensors. Depending on the sensor type employed, sensor data can be directly fed to the electronic tag 46 in digital form, or be transformed to digital format by an general purpose analog/digital converter that
typically provides a 4 or 8 bit range (although as few as one or as many as 32 bits may be required by various applications). As will be appreciated, use of such sensor systems provides additional input information that can form part of a user interface
system enabled in part by electronic tags.
In addition to sensors, various feedback displays can be attached to electronic tags 46. For example, electronic tag activation and operation may be indicated by appropriate user feedback from devices positioned either near the electronic tag 46
or near the electronic tag reader 20. For example, LED status light 49 near the electronic tag 46 and LED status light 21 near the electronic tag reader 20 can be set to provide an intermittent or steady visually perceptible light when the electronic
tag is actively transmitting to the electronic tag reader 20, providing visual confirmation to a user of data transfer. Optionally, a conventional passive or active matrix liquid crystal display such as commonly used in hand holdable computers, or a
display based on various electro optical or micromechanical techniques can be used. In addition, for certain devices a non-imaging display such as may be formed by localized or distributed chromatic changes in a suitable electrochromic materials may be
used to provide visual feedback to the user.
In some embodiments of the invention, visual output may be augmented (or even replaced) with a non-visual display. The non-visual display can include tactile displays based on internal actuators or auditory feedback. For example, one possible
feedback display is based on internal auditory speakers (emitting a range of sounds from simple "beeps" to well formed speech, depending on available processor speed and functionality) for providing user feedback. As will be appreciated, a non-visual
display and its associated actuators or electronics can support alternative feedback modes, including, for example, force feedback to a user through internal actuators, tactile based feedback (e.g. with multiple surface projections for presentation of
Braille or other conventional tactile user interface), modifications to the surface texture of the device, or any other conventional mechanism for supplying status information to a user.
As will be understood, the tag reader 20 (and tag readers 26 and 28) can be constructed to detect electromagnetic, optical, or acoustic signals at various frequencies. In certain embodiments, the tag reader 20 can write as well as read
electronic tag identification numbers and data. It will be understood that the particular digital service invoked in response to reading a tag can depend on which tag reader 20, 26, or 28 reads the tag, the order in which electronic tags are read by one
or more of the electronic tag reader, the duration of presentation of an electronic tag to a particular reader, or any other suitable user understandable electronic tag reading protocol.
After an electronic tag is read, the computer system 12 is used to interpret the identification number of the electronic tag and provide the requested digital service. Semantic binding of the identification number can be provided by a computer
14 (which can be a desktop computer, a dedicated electronic tag processor, or a hand holdable pen computer), by networked connected database servers 16, or by other accessible networked computers 18. Computers in computer system 12 can be interconnected
by various hard wired or wireless connections, and may support various communication protocols and designs, including use of a serial tethered (using, for example the RS-232C interface protocols), use of infrared signals adhering to widely utilized IRDA
communication standards, or use of radiofrequency signals (which can be, for example, a cellular telephone, 900 MHz radio, or digital PCS telephonic communications). Alternative communication standards, or even alternative communication carriers such as
those based on optical or acoustic techniques, can of course be employed. Other possible communication targets for computer system 12 include automation control systems, security authorization units, wireless personal digital assistants, notebook
computers, or any other suitably equipped electronic system.
Binding digital services to particular electronic tags can be user defined, provided as default bindings by a system provider, learned by the system through repetition or context, or some combination of these and other suitable semantic binding
techniques. For example, a database format can be constructed in which each identification number of an electronic tag is a database key. Associated with that key is a set of digital actions to undertake when that identification number of an electronic
tag is detected. There is an enumerated list of such actions--display a Web page, display a text document, display a date in a calendar, go to a certain location in a document, and so forth. Each action is parameterized by a list of (name, value) pairs
appropriate for that action. For example, the action to display a text document has pairs associated with it indicating the file to display, whether it should display in read-only mode, or whether the file should be converted to a particular format. By
using this general (name, value) mechanism, and having the database be in human-readable ASCII form, a user can easily add new tags and new types of actions to an initially provided list. Since the database is editable, associations between
identification numbers of electronic tags and digital services can be modified at any time by a user.
In addition to reading a single electronic tag and its unique identification number, the user interface of the present invention can be extended by sequentially or simultaneously reading multiple electronic tags from one or more tag readers. As
Is those skilled in the art will appreciate, each identification number or sensed data value that is read (sensed) by the tag can be labeled as a "senseme", with a particular digital service or attribute being associated with each senseme. Although the
wide variety of easily distinguishable sensemes (e.g. identification numbers) would alone provide a powerful user interface to a computer, the present invention further extends the flexibility of the senseme based user interface by supporting computer
control based on a multiple senseme input, with temporally synchronous (or overlapping asynchronous) tuples of one or more sensemes (e.g. particular identification numbers and sensed states) being read by the tag reader. Single and multiple sensemes can
in turn be extended by participation in a "sentence". A sentence is defined as a sequence of one or more temporally disjoint sensemes or senseme tuples. The sentence level allows definition of a input grammar by appropriate choice of senseme sequence,
and corollary rules governing, for example, use of active verb-like sensemes or naming noun-like sensemes. For example, the verb "print" is associated with tag 42, the textual lettering "PRINT" and the symbolic icon of a printer 62 on the polygon 50,
while the noun "http://www.test.com/DOC1.TXT", is associated with a URL to an electronic copy of a document corresponding to the printed document 30. Just as in English, context can affect how sensemes are interpreted. For example, a small model of a
printer with a tag on it can produce a senseme interpretable as either the verb "print" or the noun "printer" depending on its surrounding sensemes.
In effect, sensemes taken together form a sentence that can be interpreted as a command to implement a computer controlled action (i.e. digital service), whether it be to open and print a particular electronic document, unlock an electronically
controlled door in response to a tag conveyed personal identification number, display a graphical image on a computer display, or begin logging on to a computer network. In operation in the system of FIG. 1, for example, the sentence "establish
authorization, open a file, and print the file to printer number 3" can involve the sequential steps of reading a electronic tag 46 to establish user identification, immediately presenting an electronic tag 32 clipped to a paper document 30 to specify a
related electronic document (i.e. "http://www.test.com/DOC1.TXT") and finally presenting electronic tag 42 (positioned next to the small printer symbol) just after squeezing pressure sensor 45 three times (note that sensor 45 is electrically connected to
electronic tag 42 to pass small amounts of pressure response data) to initiate printing of the previously specified document at printer number "3". The foregoing operation conveniently distinguishes particular electronic documents, and allows a user to
select particular printers, (i.e. with printer 1 requiring one sensed squeeze and printer 2 requiring two sensed squeezes) without requiring visual displays or complex input commands.
As will be appreciated by those skilled in the art, some temporally distinguishable sensemes (or combinations of sensemes) further represent sensemes used as a basis for a grammar in accordance with the present invention. All of the following
described sensemes can be modified by numerous variations in identity of electronic tag (e.g. tag number 237654 vs. 124934), class of electronic tag (e.g. the 1000 series versus the 4000 series), presentation of sequence of particular electronic tags,
repetition or timing variations in tag presentation or sequencing, as well as sensor input such as positional information, applied pressure, force utilized in squeezing a pressure sensor. In addition, timing of various objects (whether quick, slow, or
alternately quick and slow) can modify interpretation of a senseme. For example, if "squeeze" is taken as a typical senseme supplied by a pressure sensor 45, one can appreciate various squeeze operations such as quick squeeze, slow squeeze, hard
squeeze, soft squeeze, narrow squeeze, or wide squeeze. For purposes of the present invention, all such squeeze sensemes would be considered members of the "squeeze" class, with individual variations acting as possible modifiers to electronic tag
identification number and its default semantic binding.
To better understand operation of a particular embodiment of the present invention, FIG. 2 is an illustration of a tag reading system 100 for reading an electronic tag 150 with optional connected sensor 160. The system 100 includes a hand
holdable pen computer 110 with input/output aided by pen 112 and touch sensitive display surface 114, wireless infrared or radiofrequency port 140 for communication with a network (not shown), and an attached electronic tag reader 120. The tag reader
120 is powered by line 132 to pen computer 110, and serial communications with pen 110 are maintained by serial connection 130 (e.g. an RS-232C connection).
FIG. 3 is a schematic illustration of the tag reading system 100 of FIG. 2. As seen in FIG. 3, the electronic tag 150 includes memory 152 for holding an identification number, other user or system defined data, and optionally any sensor data
from sensor 160. A processor 154 connected to the memory 152 handles onboard logic, including optional data preprocessing, power control, and transmission/reception tasks. It will be understood that the processor 154 may include only a few logical
elements, or can be a full featured microprocessor with memory 152 on the microprocessor chip. A power supply 156 (e.g. a battery, an inductive power converter, photovoltaic cells, etc.) is used to power the tag 150, and data transmissions are broadcast
by antenna 158. The tag reader 120 includes tag-reader-processor/memory-buffer 120, and electromagnetic reading coil 122.
Implementation of an electronic tag reading system similar to that illustrated in conjunction with FIGS. 2 and 3 is possible using commercially available tags from Trovan, Ltd., having a website at <www.trovan.com>(hereinafter "Trovan") and
tag readers suitably modified by connection of the tag reader to a hand holdable computer. A Trovan tag consists of a small coil and a tiny microchip connected to the coil, collapsing the memory 152 and processor 154 into a single logic module, and
collapsing the antenna 158 and power supply 156 into a single coil that inductively powers the tag and broadcasts tag identification information. A Trovan tag has no associated optional sensor 160, and there is no on tag battery, with power being
transferred to the tag from the reader 120 at each interrogation cycle. Typically a reader 120 will initiate an interrogation cycle by generating a field alternating at a frequency of 128 kHz. If it is close enough to a tag, the changing field will
induce a current in the coil contained in the tag. This current can be rectified and used to charge a capacitor that after sufficient time will have enough stored charge to power its attached integrated circuit. When this condition is met, the chip
will activate an oscillator at half the interrogation frequency and this signal is fed back into to the tag coil. The tag reader 120 is designed as a full duplex system-it can receive and transmit concurrently. The reader's sensitive receiver is tuned
to exactly half of the interrogation frequency and is listening for a phase-modulated signal from the tag at 64 kHz. During this process the tag will modulate the response signal with a data frame containing 64 bits of information. Each frame will
contain an organization or client code, a unique ID code and a checksum. For each client, 2.sup.39 tagging codes are available (approx. 550 billion).
Various sized Trovan tags can be used in the present invention. Larger tags contain a larger coil, but have similar electronics to the smaller versions. Larger tags have a greater read range. The tradeoff between tag size, reader coil size,
and read range is governed by the application. The following reader and tags have been tested in system 100: LID 656 tag reader; ID 100A --cylinder tag (2. | | |
