GB2511216A - Determining a path of a wireless tag - Google Patents

Abstract

A reader 19 for a near field communication (NFC) tag, where the tag is in a mobile communications device, and the reader 19 includes a processor 31 to identify the tag, determine a path of the tag, to identify an instruction in dependence upon the path and in response to the instruction, performing a predetermined function. Also claimed is a mobile phone comprising an NFC chip, where the cell phone is configured to, in response to a reader 19 cooperating with the tag to determine a path of the tag, perform a predetermined function. The predetermined functions of both inventions may be pairing the phone with a computer and syncing files or emails either between them or to the phone.

Description

Determining a path of a wireless tag

Description

the present invention relates to determining a path of a wireless tag and a user input device.

\Vireless tag technologies, such as radio frequency identification (REID) and near-field cornniunication (NEC), have many applications including access control, inventory management and electronic payment.

Tags can a]so he used in the home or office to trigger retrieva] of data or sending of messages. A tag reading device is connected to a persona] computer or mohi]e telephone which is connected to the Internet. Articles or items, such as a set of keys, umbrella, book or postcard, can be tagged with a wireless tag. Placing a tagged item on the tag reading device triggers an appropriate action. For example.

the item may be a set of keys. \Xthen a user arrives or leaves home they can place the set of keys on the tag reading device. this can trigger, for example, sending of an e-mail to report that the user has arrived home or is on their way to work. In another example, the item may he an umbrella. The user can obtain a weather forecast, by passing the umbrella over the tag reading device. However, the tag reading device has a drawback that it can provide on]y]imited contro]. For examp]e, it can on]y he used to trigger one predefined action for an artic]e.

Wireless tags can be used in other applications. For example, US 2006/0125691 Al describes a motion capture system for digitising movement of an actor and creating images for use in motion pictures,video games and virtual reality systems. The system includes at least four stationary receivers placed at known positions around a capture zone, at least one stationary radio frequency transmitter defining a reference tag and a number of radio frequency transmitters defining marker tags that are placed on the actor. A processing algorithm is used to compute double difference measurements using pseudorange measurements from the reference tag and the marker tags. The motion capture system is on]y used to track tags. Moreover, it requires considerable processing power. Each radio frequency receiver employs several floating point digital signal processors (DSPs).

As explaine.d earlier, a tag reading device, can be used to trigger retrieval of data.

Other different types of information access system are known. For example, "InfoRod" is a swing motion based information access method for use in a public area. A cellular phone has a three-axis accelerometer and a GPS sensor. When the user sees a poster, they can swing their cellular phone. Motion is detected by the accelerometer and, based on the motion and location, the cellular phone can retrieve a URT. over the cellular network. The user can employ a web browser on the cellular phone to follow the URI.and retrieve information. Tjowever, this type of information access system requires an accelerometer-enabled cellular telephone.

According to a first aspect of the present invention there is provided a device comprising processor For analysing signals dependent upon responses of at least two antennas which are spaced apart so as to allow detection of a path taken by a wireless tag when waved or moved by a user, the processor configured to deterniine a path of the wireless tag and to identify an instruction in dependence upon the path.

thus, the device can be used to analyse a gesture, captured by the antennas, made by the user holding the wireless tag or an article carrying such a tag and executing a corresponding instruction or command. Different gestures can he used to give different instructions, each gesture triggering a different action. This can help to provide a more powerful user interface. _Moreover, the wireless can he used to identify the user and so help to ensure that only authorised users provide instructions.

To detect the path, the processor need not compute range, hut can simply detect proximity to antennas, for example, by simply determining whether the tag is present. Using proximity-based measurements can help to provide robustness against noise and reduce power consumption compared, for example, with action-at-a-distance range-based measurements.

the processor may comprise, a multi-core. processor or multiple processors. The processor n-lay comprise a microcontroller or other processing system.

The device may comprise at least two antennas which are spaced apart so as to allow detection of a path taken by a wireless tag when waved by a user.

Thus, the device can he used as a user input device by capturing a gesture made by the user holding the wireless tag or an article carrying such a tag and executing a corresponding instruction or command.

Adjacent antennas may be spaced apart by a distance between about 1 cm and about cm. Thus, the user can make. small gestures, e.g. by waving their hand at the wrist. Ho\vever, adjacent antennas may he spaced apart by a distance by nx)re than about 10 cm and so the user can make larger gestures, e.g. by waving their arm.

Lach antenna may comprise a coil or loop.

The device i-nay comprise a wireless tag reader operatively connected to the antennas and to the processor. This can he used to validate the tag and, thus, act upon gestures made using a valid tag.

The device may further comprise a multiplexer for operatively connecting the wireless tag reader or the at least one processor to the antennas.

The device may he conFigured, in response to an antenna receiving a signal From the tag, to provide feedback to the user. For example. the device may comprise light emitters, such as light emitting diodes, wherein each antenna is provided \vith a respective light emitter and the device is conFigured, in response to a given antenna receiving a signal From the tag, to illuminate a respective light emitter. This can help the user to track their gesture.

The device may he configured. in response to identifying the tag, to provide feedback to the user. lot example, the device may comprise at least one light emitter, for instance a green light, and the device may be configured, in response to identifying the tag, to illuminate the light emitter. Additionally or alternatively, the device may comprise a sound emitter and the device may he configured, in response to identifying the tag, to output a signal, e.g. a synthesised voice, via the sound emitter.

The processor may he configured to compare a signal pattern dependent upon responses of the antennas with at least one signal pattern so as to identify the path The processor may he configured, in response to identifying the path, to provide feedback to the user. lor example, the processor may confirm the instruction.

The processor may he configured, in response to the instruction, to transmit a signal to another device. The processor may also he configured. in response to receiving a reply from the other device., to provide feedback to the user.

The wireless tag is a radio frequency identity tag or a near-held communication device.

the device may be configured to identify orientation of an object having more than one wireless tag. Thus, more complex gestures can he used.

According to a second aspect of the invention there is provided a method comprising determining a path of a wireless tag and identifying an instruction in dependence upon the path.

According to a third aspect of the invention there is provided a computer program which, when executed by data processing apparatus, causes the data processing apparatus to perform the method.

According to a fourth aspect of the invention there is provided a computer program product comprising a cornpute.r readable medium storing the computer program.

Lmbodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a schematic diagram of a home and a home automation network deployed in the home including an input device; Figure 2 is schematic block diagram of an input device; Figure 2a illustrates non-volatile memory in an input device; Figure 3 is a perspective view of an example of an input device; Figure 4 is schematic block diagram of a wireless tag; Figure 5 is schematic block diagram of a home automation network manager; Figure 6 illustrates a first pattern made by moving a tag; Figure 7 illustrates a second pattern made by moving a tag; Figures Ha to Sd illustrates strokes made by moving a tag and \vhich can he linked to form complex patterns; Figures Se to Hg illustrate patterns comprising linked strokes; Figure 9 is a process flow diagram of a method of operating an input device; Figure 10 illustrates exchange of data between an input device and a home automation network manager or other device; and Figure ii illustrates another system including an input device and another device, such as a personal computer.

Referring to Figure 1. a network 1 is shown comprising a plurality of nodes 2.and a main node 3 (herein referred to as a "home automation network manager" or "home automation box") arranged in a point-to-multipoint or mesh configuration and deployed in a home 4, e.g. house, flat or other residential environment.

However, the network may he deployed in commercial environments, such as shops, offices or hotels, in industrial environments, such as a factory shop floor, public or municipal environments, such as railway stations and leisure centres, and other non-residential environments.

Nodes 2 can be wirdess]y connected to the home automation network manager 3 either directly or via an optional range extender 5 through respective low-power, low-data rate, short-range wireless data links 6, for example conforming to LigBee.TM specification and IEEE 802.15.4 physical radio standard. However, other low-power, low-data rate, short-range wireless standards may he used.

Some or all of the nodes 2 can he connected via wired links, such as universal serial bus (USB) or wired Ethernet connections.

Jo The network manager 3 serves as a coordinator for the network I providing networking facilities, such as device and service discovery caching and, opttonafly, channe' management and trust centre operations. The network manager 3 asc provides TCP/iP gateway functionality via hub 7 and broadband modern 8 to an external network 9. As shown in ligure. 1, the external network 9 can he used to access, for example, telecommunication company server(s) 10, web server(s) 11 and e-mail server(s) 12.

As shown in Figure 1, the nodes 2 can be grouped according to different uses or applications including. for example, security-related devices 13, power control and profiling devices 14 and configuration and analysis devices 13.

the security-related devices 13 may include an alarm system 16, intrusion detection sensors such as passive infrared detectors 17 and floor-based pressure sensors 18.

The security-related devices 13 may include one or more devices 19 for providing user input (herein also referred to as an "access panel"). The user input device(s) 19 can he used, for examp'e, to activate and deactivate the alarm system 16.

The power control and profiling devices 14 may include one or more power monitoring devices 20 for detecting current F'owing through mains power cabk(s).

The power monitoring devices 20 may he instafled at various points throughout the electrical power distribution system in the home. For example, a device. 20 may be installed in or imnediately downstream from a distribution board (not shown) for measuring power consumption for the. whole. home. A device 20 may be provided for each or some circuit, e.g. lighting circuit, first floor circuit, room circuit etc. Powe.r monitoring device(s) 20 may have sockets 2i for receiving plugs 2i for supplying power to appliances 22, such as television sets, media players, game consoles, computers, microwave ovens and other household (or office) appliances.

The configuration and analysis devices 15 can include a personal computer 23 xvhich may or may not he a node 2 forming part of the wireless network 1) and a portable display device 24.

As explained earlier, there tnay he one or more user input devices 19 A user input device 19 may he connected to the network manager 3 by a wireless or wired link.

A user input device 19 can take one of many different forms and may be located at a convenient or appropriate location. For example, a user input device 19 niay he located inside or outside the home 4 by a front door, hack door or other external door or exit. Additionally or alternatively, a user input device 19 may he positioned next to a home computer 23. A user input device 19 need not he a suand-alone device, hut can he integrated into another device, such as the network manager 3, appliance 22 or home computer 23. There may he more than one user inpnt device 19. For example, devices 19 may he located on either side of a door.

As will be explained later, a user input device 19 need not be used as part of a home automation network 1 and can be used in other applications which may be primarily intended for the user's personal or private use, or for public use. For example, the user input device 19 can he used, for instance, in conjunction with a computer 91 (Figure 11) or vehicle. Alternatively. the user input device 19 can he used, for example, in a ticket barrier for a transport system.

A user input device 19 cooperates \vith one or more wireless tags 23 to allow a user to provide user input by capturing a gesture made by a user holding the tag 23. The tag 25 may he incorporated or carried by an article or item, such as a set of keys.

Gestures may include, for example, waving the tag 25 in a single pass from left to right, waving the tag multiple times back and forth or tracing out more complicated patterns, which can be made, for example, by flicking wrist or waving the arm. the response of the user input device 19 may depend on the identity of the tag 25. For example., the user input device 19 can be programmed to trigger different actions in response to the same gesture but made using different cards. Furthermore, the user input device 19 may only respond if the tag 25 is recognised or validated. Thus, the user input device 19 can he used to provide secure user input.

In some embodiments, the article or item (herein also referred to as an "object") may have more than one tag 25. Thus, the user input device 19 can he used to determine the orientation of the object. This can allow more complex gestures to be used involving, for example, turning or flipping over the object.

Referring to Figures 2 and 3, circuitry 26 of the user input device 19 is shown.

the user input device 19 includes an antenna array 27 comprising t\vo or more antennas 28, an array controller 2, a tag reader 30, a processor 31, for example in the form of a microprocessor, non-volatile random access memory 32 and volatile random access memory 33. An antenna 28 may take the forni of a loop, coil or other coupling element. The array controller 29 allo\vs a single tag reader 30 to be used with more than antennas 28 by, for example, multiplexing signals. The tag reader 30 is used to interrogate the tag 23, for example, by supplying an energiaing signal and demodulating a backscattered signal. the processor 31 nuy take the form of a microcontroller or other form of processing system. the processor 31 may he divided into more than one block, unit or system. For exaniple, the processor 31 may include a processor for analysing signals and another processor for controlling the rest of the device.

The user input device 19 can provide feedback to the user via one or more light emitting diodes 34 and a speaker 33. For example. light emitting diodes 34 (or outputs of light gvides connected to light emitting diodes 34) can he placed in front of, behind, in the middle of or around respective antennas 28 and arranged such that a light emitting diode 34 lights up when the tag 25 is successfully read by the corresponding antenna 28. Optionally, a display 36, for example in the form of a liquid crystal display, can be provided.

the user input device 19 also includes network interface 37. For example, the network interface 37 can take the form of a LigBeeIM wireless transceiver \vhich is connected to an antenna 38. However, the network interface 37 may be network card connected to a wired connection 39, e.g. twisted pair, Ethernet, USI3 etc. The user input device 19 may include buttons, keypad, scroll wheel, joystick, touch screen or touch pads, slider bar etc. or other forms of input device.

The processor 31 and other parts of circuitry 26 arc powered by a battery 40.

Additionafly or alternatively, the device may include a power sUPPlY unit 41 powered via a mains supply 42.

Referring also to figure 2a, the non-volatile random access memory 32 stores a set of patterns 43 and corresponding instructions 44 As will he explained in more detail later, the processor 31 identifies a path taken by the tag 23 (Figure 1), tries to match the path to one of the patterns 43 and, thus, identify a corresponding instruction 44 Alternatively, it can record the responses of the antennas 28 and report these to another device, e.g. network manager 3, which identifies a path taken by the tag 23 (Figure 1). The non-volatile random access memory 32 also stores a list of identities 45 of one or more registered tags 25 (Figure 1). the non-volatile random access memory 32 also stores software 45 for controlling the device 19.

Referring to Figure 3. an example of a form factor of the user input device t9 is sh own.

The user input device 19 has'afr()nt face 47 which may carry printed indicia 48 for identifying an area or areas where the user should present the tag 25 (Figure 1). The antennas 28 are disposed behind the face 47. The device 19 might he arranged to lie on a horizontal surface, such as a desk-or table-top or shelf, or be mounted on a vertical surface, such as a wall.

The user input device 19 may take different forms and the antennas 28 may be arranged differently. For example., the antennas 28 may be placed on or behind more than one face. the antennas 28 need not be arranged in one plane. At least a portion of the front face 47 may be translucent for allowing light emitting diodes 34 located behind the cover to he seen \vhen illuminated. The antennas 28 may he placed behind a protective sheet, e.g. formed of glass or plastic. In some embodiments, the input device 19 may be provided behind a sheet of glass, e.g. in a shop, bank, information kiosk or other commercial or public place.

Referring to Figure 4, circuitry 50 of the wireless tag 25 is shown. Tn this example, the wireless tag 25 is a passive device which harvests po\ver froni the input device 19 (Figure 3). ITcvever, the wireless tag 25 be differently configured. For example, the wireless tag 25 may he an active device and naay have its own power source, such as a battery.

The wireless tag 25 includes an antenna 51 and a controller 52 which is operatively connected to non-volatile menaory 53. The tag 25 includes a power management unit 54 which is connected to the antenna Si which harvests power From an interrogating held generated by the tag reader 30 (Figure 2) by rectiFying an a.c.

signal and supplying a d.c. voltage to the controller 52. The tag 25 also includes a demodulator 55 and a modulator 56.

Referring to Figure 5, circuitry 60 of the home automation net\vork manager 3 is sho\vn in more detail.

The netvork manager 3 includes a network interFace 61, For example in the Form oF a ZigBee (RT?vl) \vireless transceiver, user input device(s) 62, e.g. in the form of one or more keys or buttons (not shown), output device(s) 63, e.g. the form of one or more light emitting diodes (not shown), a processor 64, For example, an ART\l (RTM) -or Po\ver-PC (RTM) -based processor, non-volatile random access memory 65, volatile random access memory 66 and a wired network interface 67. The network manager 3 is mains-powered, but may have a rechargeable battery (not shown) as a back-up supply.

the network manager 3 may have an antenna 68 for communicating wire.lessly with the device 19 and other devices 2. Additionally or alternatively, the network manager 3 may have a wire connection 69.

Referring again to Figure 1, the user input device 19 is used to capture motion of the tag 25 and, in some cases, to cooperate with the network manager 3.

Referring also to Figure 6, the user input device 19 and the tag 25 are shown in use.

In this example, the user input device 19 has two antennas 28 having respective interaction regions or spaces 70. Tn this example, the interactions regions 70 do not overlap. This can help to resolve, the position of the tag 25. However, in some e.ml)odiments, the interactions regions 70 may overlap which can allow the position of the tag 25 in space to he computed.

the user passes the tag 25 from left to right along a path 71 which crosses the interaction region 70 of the first antenna 28 and then the interaction region of the second antenna 282.

As will be explained in more detail later, the processor 31 (Figure 2) identifies this path 71 as corresponding to a pattern 43, namely a single pass in a forward direction (i.e. left to right. as illustrated in Figure 6a.

This action can he used to provide a first instruction. A second, different instruction can he provided by another action, e.g. a single pass in a reverse direction (i.e. right to left).

\Vith two antennas 28 as shown in Figure 6, additional actions may include single passes at different speeds and multiple passes. e.g. repeated stokes or strokes hack-and-forth. -12-

Additional antennas 28 can be used to allow detection more complex actions and, thus, aiiow for a larger "alphabet" or "vocabulary" of gestures and instructions.

lor example, referring to Figure 7, the user input device 19 may have five antennas 28 arranged in a cruciform shape and having respective interaction regions 70.

The user can pass the tag 23 up the middle or spine of the cruciform and turn back on the right-hand side to pass a right side antenna to form a path 71. This is a more complex pattern 43, i.e. a single, right-hand turn.

The antennas 28 and the interaction regions 70 may be differently configured to detect different gestures and paths.

Referring to Figure 8a to Sd. a set of simple patterns 43k, 433. 434 are shown.

These patterns 43, 43, 43 include single passes Fonvards and reverse, i.e. right, left, up and do\vn.

To distinguish all four of these simple patterns 43. 433. 434, three or more antennas 28 (Figure 2) are he used. For example, three antennas 28 (Figure 2) may he arranged in a triangle, Four antennas 28 (Figure 2) may he arranged in a rectangle (particularly a diamond), five antennas 28 (Figure 2) can be arranged in a cruciform, for example as shown earlier in Figure 7, or nine antennas can be arranged in a three-by-three rectangular array. Other antenna arrangements can he used. These naay he regularly arranged, for example in a rectangular or polar array, or irregularly positioned, for example randomly.

Additional patterns may he defined by virtue of the speed of a stroke. For example, eight patterns can he defined using the basic strokes depending on whether the stroke is fast (e.g. made by a quick Hick of the wrist) or slowly (e.g. made by gently and smoothly swiping the tag 25 over the course of a few seconds).

Referring to Figure 8e and 8f, a first set of more complex patterns 43, 43, is shown.

these patterns 434, 43 include repeated strokes (e.g. two, three or more times) in the same direction. Between strokes, the tag 25 may he lifted away from the device 19 beyond the interaction regions 70 (ligure 6), for example, by more than 10 cm from the surface of the device.

Referring to Figure 8g and 8h, a second set of more complex patterns 43,, 43 is shown. These patterns 437 include at least one forward stroke and at least one back stroke, e.g. fonvards and then backwards (or vice verca, or forwards, backwards and then forwards again. A similar set of patterns can he formed using strokes up and down.

Referring to Figure 8i and 8j, further complex patterns 439, are shown. These patterns 439 include at least one stroke in one direction and at least one strike in a transverse (e.g. orthogonal) direction.

Tn Figures 8a to 8j. strokes are shown which are aligned along orthogonal directions. 1-Towever, strokes can he misaligned (e.g. rotated by a few degrees) while still having a significant component in these directions.

The antennas 28 (Figure 2) can he arranged to detect non-orthogonal strokes, e.g. diagonal strokes.

Other patterns can be defined. For example, the patterns need not comprise straight-line strokes. hut can he arcuate or serpentine.

Complex patterns can he assembled from simpler patterns and strokes. For example, straight-line and curved strokes can he combined.

As mentioned earlier, if more than one tag is used, then the antennas 28 (Figure 28) can be used to determine the orientation of an object.

A stroke can have an orientation or "sense". For example, a stroke from left to right can be made with an object facing up or down. thus, the device 19 can be -14-used to distinguish between an "up-facing" stroke and a "down-facing" stroke. An orientation can include a combination of pitch, yaw and/or roll.

A stroke can start, finish and/or be punctuated by changes in orientation. lor example, a stroke from left to right may he followed by a 90 degree turn of the object (e.g. by a "a" or in-plane turn of the hand at the wrist) or a 180 degree flip of the object (by a "roll" or twist of the hand or wrist) and then followed by another stroke, for example from right to left. A change in orientation can he used to mark or delineate a section (or "phrase") within a gesture. A change in orientation, such as an open or close action (by a "pitch" or raising or lowing of the hand relative to the wrist), can be used to signal to start or end of stroke or gesture.

A stroke can include changes on orientation during a stroke. lor example, the object can he turned, flipped and/or rotated \vhile being moved.

Referring to Figures 2, 4 and 9, a method of operating the nser inpnt device 19 will now he described.

In a "standby" state, the array controller 29 and tag reader 30 cooperate to poll all or some the antennas 28, For example in a predeFined order (step SI) until a tag 25 is detected (step 82). For example, an antenna 28 in the array 27 may be polled every few hundreds of milliseconds. However, as will be explained later, an antenna 28 can he polled more slowly, for example every second or so. or even not polled at all.

All of the antennas 28 can he polled. T-Iowever, if there are a large number of antennas 28, then this might result in each antenna 28 being polled too infrequently.

For exaniple. the tag reader 30 and/or processor 31 may only he able to poll antenna(s) a given number, p. of times every second (e.g. about 15 times a second).

Therefore, if there are q antennas, then it may he only possible to poil an antenna about p/q times every second. In some cases, this poll rate may be too slow to detect the beginning of a stroke reliably. therefore, in some embodiments, only those antennas 28 located where a stroke is expected to begin need be polled. -15-

Iwo or more of the antennas 28, for example all of the antennas 28, can be polled simultaneously. this can be used to detect the presence of an antenna, but not necessarily the position of an antenna.

If a tag 25 is detected, then the processor 31 (using data received from the array controller 29 or tag reader 30) identifies the antenna 28 which first detected the tag (step S3) and using data received from the tag reader 30 identifies the tag 25 (step 54). These steps may he performed by the tag reader 30.

The processor 31 determines whether the tag 25 is registered (step Si), for example, by comparing the identity of the tag 25 with one or more identities 45 stored in memory 32.

Tf the tag 25 is not recognised, then the processor 31 may provide Feedback to the user (step 56). for example, by illuminaring a red light emitting diode 34, displaying a suitable naessage (such as "lag not recognised") on a display 36 and/or causing the speaker 35 to output a suitable audible signal.

IF the tag 25 is recognised, then the processor 31 may provide feed back to the user (step 57), for instance, by illuminating a green light emitting diode 34, displaying a suitable message on a display 36 and/or causing the speaker 35 to output a suitable audible signal.

If an object carries more than one tag 31, then only one tag need he identified.

However, in some embodiments, more than one tag can he identified.

Once a tag 25 has been detected, the processor 31 naay switch into an "active" state, in which the antennas 28 are polled more regularly and/or signals are processed differently.

In an "active" state, the array controller 29 and tag reader 30 continue (or start) to poll the antennas 28 in order to identify the path of the tag 25 (step 58). The antennas 28 may be polled more frequently than in the standby state, for example.

every few tens of milliseconds.

the array controller 29 and tag reader 30 need not poll all of the antennas 28. For example, if an antenna 28 reads the tag 25, then that antenna 28 need not he polled again immediately. This is because it can he assumed that the tag 25 will move and, thus, not linger at that antenna 28 currently detecting it Additionally or alternatively, only antennas 28 which are immediately adjacent to the antenna 28 currently detecting it need he polled. In certain embodiments, only antennas 28 which lie on possible paths of the moving tag 25 need he polled.

If an antenna 28 is not polled, then it may be omitted from polling for an appropriate number of poll cycles or for a given duration of time. the number of poll cycles or the duration of time may he fixed. e.g. one or two cycles or a given number of milliseconds. Alternatively, the number of poll cycles or the duration of time may depend on, for example, at \vhich point during the stroke the tag is thought to he and/or vhether the tag is expected to return to the sanie position.

For example, if the antenna is located at the beginning of what is expected to he a long straight stroke, then the antenna need not he polled for some time. On the other hand, if the antenna is located in the middle of a pattern which is expected to go back and forth several times, then the antenna can be polled sooner.

Limiting the number or antennas 28 polled, in particular not polling an antenna which has just detected the tag, can help to avoid accidental detection and, in particular. particularly multiple accidental detection by the same antenna.

Two or more of the antennas 28 can he polled simultaneously. This can he used, for example, if there are a large number of antennas' and the device determines, part way through a stroke, that the stroke is expected to he simple and that resolution is not critical.

the processor 31 identifies which antenna 28 currently senses the tag (step 89) and may provide feedback to the user (step 810), for example, by illuminating a light emitting diode 34 associated with the antenna 28. The processor 31 may determine that more than one. antenna 28 can sense the tag 25. If more than one antenna 28 can be identified, then the processor 31 may infer a position of the tag 25.

The processor 31 receives and stores data regarding the path 71 taken by the tag 25, for example in terms of antenna (position) with time. If there is more than one tag, then the processor 31 can record data regarding the path of each tag.

Data points may he spaced evenly in time and may take the form n, t} where n is antenna identity and t is time. Thus, taking the example shown in Figure 6, a set of tag NTh data points may take the form of, for instance, { 1, 0) ,{ 1, 500) ,{2, 1000) and { 2, 151)0), where n = 1 or 2 depending on whether the left-hand or right-hand antenna 28. 28 detects the tag 25 and time is measured, for example, in milliseconds. Other ways of encoding antenna identity and time may he used. Also, the time period may he different, e.g. more frequent or less frequent.

Data points need not he measured regularly in time, hut can he recorded, for example, whenever a new antenna detects the tag 25. Tn some embodiments, particularly if interaction regions 70 overlap, data points can he recorded and a position can he calculated, e.g. using triangulation. Furthermore, data points can he processed, for example, using statistical analysis, to find a most probable path or to remove anomalous data points.

The processor 31 continues to poll antennas 28 and to identify the antennas 28 which sense the tag 25 until it determines that the user has finished gesturing (step SI 1), for example, by identifying that no antenna 28 has sensed the tag 25 for a predetermined period of tinie (e.g. one second or a fe\v seconds) or until a pattern has been recognised. For example, this may include the same antenna detecting the tag successively a given number of times or for a given duration of time, i.e. indicating the tag is being held in the same place.

this technique can also be used to prime the device 19, i.e. to switch the input into an "active" state, at the beginning of the process. Ihe user can ready the device by holding the tag in the same position so that the same antenna reads the tag in several polling cycles. Once the device 19 has captured the tag identity, it can notify the user by providing positive feedback, which provides a cue to the user to carry out the stroke.

The processor 31 may try to predict the pattern while the user is still gesturing.

This can he used to set a time limit for continu ng to capture signals from the antennas 28. This can he helpful to provide faster response. For example, if the user makes a stroke and patterns are formed from a maximum of two strokes, then the processer 31 may keep aflow pofling of the antennas 28 fir the time it expects the second stroke to take. A Viterbi (or similar) algorithm can be used to identify the pattern, for exatnp]e, in real time.

If more than one tag is used, then orientation can be determined by comparing positions of tags 25.

Once the processor 31 determines that the gesture has finished or that it has enough data, the processor 31 compares the path with patterns 43 stored in memory 32 (step 512).

If the processor 31 cannot match the path with one of the patterns 43, then the processor 31 may provide feedback to the user (step S13), for example, illuminating a red light emitting diode 34. displaying a suitable message (such as "Gesture not recognised") on a display 36 and/or causing the speaker 35 to output a suitable audible signal.

If the path is recognised, then the processor 31 may provide feedback to the user (step 514), for instance, by illuminating a green light emitting diode 34. displaying a suitable message on a display 36 and/or causing the speaker 35 to output a suitable audible signal. The message may prompt the user to confirm the action.

the processor 31 executes the instruction associated with the gesture (step S16) and, once the instruction has been completed, may report this to the user (step S 17).

As explaine.d earlier, in the "standby" state, an antenna 28 may be polled, for example, every few hundreds of milliseconds. However, slower polling (e.g. with a periodicity of about I s or longer) can be used. Furthermore, one or just a few of the antennas 28 can he polled. For example, if the tag 23 can he detected when it is still several centimetres away from the device 19, then the device 19 can wakeup' or he activated' whereby faster polling is used and/or additional antennas are polled. This can help to reduce power consumption.

During a polling cycle in the standby state, antennas 28 can he polled in quick succession. For example, if a first antenna is polled at time t1, then the next antenna may be polled at time t2 = t1 + A, where A maybe of the order of 10 or 100 ms. However, the periodicity, p, with which an antenna 28 is polled may he largely determined by the length of a delay, d, between finishing one cycle and starting another, where d >> A. For example, the first antenna may he polled in a first cycle at time t1 and is polled in a second subsequent cycle at tinie t1 + d.

Likewise, during a polling cycle in the active state, antennas 28 can be polled in quick succession which may be even quicker than in the standby state. For example, if a first antenna is polled at time t1', then the next antenna may he polled at time t2' = t1' + A', where A' is less than A. A delay, d'. between finishing one cycle and starting another may be introduced.

The values for time differences, A and A', between polling antennas in one cycle and, if used, the delay, d and d', between cycles can he found by routine experiment.

The values may depend on the spacing of the antennas and also on the interaction range. The duration during which an antenna is activated in the standby and active states, s and s', may also he found by routine experiment. The values may depend on the response time of antenna 28, processing speed of the tag 23 and processing speed of the tag reader 30.

In an active state, once the tag reader 30 has identified the tag 25. it need not identify the tag 23 again. This means that a shorter excitation signal can he used -20 -and/or the response from the tag need not he processed in fufl to obtain a tag identifier.

As explaine.d earlier, the input device 19 can be. used in a home automation network 1 and can cooperate with a network manager 3.

Referring to Figure 10, the input device 19, having captured a gesture and identified an instruction, can send a message 80 to the net\vork manager 3 (step S 16.1) for the network manager 3 to perform (step S16.2). The message 80 may include the identity of the tag 23 and the instruction. The message 80 may he divided into sub units. The message 80 may be encrypted. Once the network manager 3 has carried out the instruction, e.g. retrieving data, setting an alarm etc., it can send a reply 81 confirming that the necessary action has heen taken (step 516.3). The. device 19 may perform an action, for example, by storing data (step 516.4).

In some embodiments, the input device 19 does not identify the pattern. Tnstead, the input device 29 records a set of tag path data points and, once the stroke has finished or time out occurred, sends a message, including the identity of the tag and the data points, to another device where the pattern is identified.

As explained earlier, the input device 19 can be used in other applications and need not be used in a home automation network.

Referring to Figure 11. a system 90 is shown which comprises the input device 19 and a personal computer 91, e.g. desktop computer, laptop computer or PDA. The input device 19 may he integrated into the computer 91. The personal computer 91 may he networked, e.g. connectable to a network 92.

The input device 90 can he used to provide secure user input. For example, the input device 90 can he used in a similar \vay to a smart-card reader, e.g. to log into the computer 91. however, gestures can be used to provide instructions including, for example locking the computer 91, switching the computer 91 into sleep mode, retrieving c-mails and opening or closing a particular application. -21 -

If the tag 25 is a near field communication tag, then additional functionality may be provided. For example, the tag may form part of mobile comnaunications device, e.g. a smart phone. thus, an appropriate gesture may be used to pair the device with a computer, synchronise files or c-mails. etc. Tags maybe registered with user input device 19 (Figure 1 & 11) in different ways.

For example, the network managerS (Figure 1) or computer 91 (Figure 11) can have a control panel which the user can access to identify a new tag. Additionally or Jo alternatively, tags can be registered using the input device 19 (Figure 1 & 11). For example, a user can gesture with an existing tag 25 (Figure 1 & 11) to instruct the input device 19 (Figure 1 & 11) to register a new tag. The user then swipes the new tag to allow the user device 19 (Figure 1 & 11) to obtain and store the identity of the tag.

The user input device 19 (Figure 1 & Ii) may he arranged such that the action or path produces different results using different tags. Thus, in the case of honae automation network, a user (e.g. a parent or guardian) can have a master' tag \vhich can he used to control alarms and other important functions, as well as other less-important functions, such as switching on lights. Other users may possess a tag which only allows them to switch on lights.

It will he appreciated that many modifications may he made to the embodiments hereinhefore described. For example, polling can he controlled different combinations of the array controller, tag reader and processor. one or naore of these elements can he combined into a single block.

Claims (6)

1. -22 -Claims 1. A reader for a near field communications tag included in a mobile communications device, the reader comprising a processor configured to identify the tag, to determine a path of the tag and to identify an ins truction in dependence upon the path of the tag and, in response to identifying the path, to perform a predetermined function.
2. 2. A reader according to claim 1, wherein the predetermined function is to pair the device with a computer.
3. 3. A reader according to claim 1, wherein the predetermined function is to cause synchronisation of files or c-mails with the device.
4. 4. A mobile communications device comprising:a near field communication tag;wherein the mobile communications device is configured, in response to a reader cooperating with the tag to determine a path of the tag, to perform a predetermined n c tio it
5. 5. A device according to claim 4, wherein the predetermined function is to pair with a computer connected to the reader.
6. 6. A device according to claim 4. wherein the predetermined function is to cause synchronisation of files or c-mails.