WO2011061511A1

WO2011061511A1 - Controller device for a computer

Info

Publication number: WO2011061511A1
Application number: PCT/GB2010/002150
Authority: WO
Inventors: Cuauhtemoc Rodriguez; Duncan Smith; Adam Geernaert; Matthew Hill; Matthew Hayes; Gary Ewer
Original assignee: Cambridge Consultants Limited
Priority date: 2009-11-20
Filing date: 2010-11-22
Publication date: 2011-05-26

Abstract

A controller device for inputting hand- manipulations of a user to a computer comprises a core (70) or support, a resiliently deformable layer (10, 102) that at least partly surrounds the core or support and which can be deformed by application of force by the user. The deformable layer comprises a resistive foam having an electrical resistivity that varies in dependence on the degree of compression of the foam, and the device includes a conformable complementary layer that is located on the deformable layer and is electrically conductive. The core or support and the complementary layer can generate an analogue output that is dependent on the separation between the complementary layer and the core or support. The device has a detector circuit for receiving the analogue output and transferring it to the computer. The deformable layer may comprise a foam filled with a conductive filler. Alternatively, the device may comprise means for forming a magnetic field and an array of sensors, e.g. Hall effect sensors on the deformable layer, In another for of device, optical radiation may be generated and may be detected by means of an array of optical sensors.

Description

Controller device for a computer

This invention relates to computers, and especially to controllers for inputting data or commands thereto.

There are many instances where it is necessary to input non-verbal commands to a computer, for example in the field of CAD, instrument control and computer games, and it is usual for the input device to comprise a mouse or other controller in which buttons are provided for execution of specific commands. Such devices, however, have the disadvantage that it is necessary for the user to ensure that his or her fingers are in register with the relevant buttons. More recently, it has been proposed to employ an input device that does not necessarily include buttons, for example as described in US 5,262,777 to Low et al, and which comprises a generally spherical object comprising a solid shell, a rubber surface and therebetween an array of force sensors of undefined nature. However, this device is relatively rigid and has an inappropriate "feel" for controlling a computer for many applications. It is also easier for the user to gauge the amount of pressure he is applying if that is accompanied by some degree of movement rather than simply relying on his appreciation of the pressure that is applied. Other forms of input device which allow a degree of movement have the disadvantage that the sensors in the array are very intricate and delicate with the result that the device will be expensive to manufacture or will be easily broken.

According to one aspect, the present invention provides a controller device for inputting hand- manipulations of a user to a computer, the controller device comprising a core or support, a resiliently deformable layer that at least partly surrounds the core or support and which can be deformed by application of force by the user, the deformable layer comprising a resistive foam having an electrical resistivity that varies in dependence on the degree of compression of the foam, and the device including a conformable complementary layer that is located on the deformable layer and is electrically conductive or has a plurality of electrically conductive elements therein, the core or support and complementary layer being operable to generate an analogue output that is dependent on the separation between the core and the complementary layer, and the device having a detector circuit for receiving the analogue output and transferring it to the computer.

The invention has the advantage that it is possible to design the controller device so that the surface thereof undergoes a significant degree of movement as it is being compressed or squeezed, thereby giving the device a better feel, and allowing the user to determine more easily the degree of force that is being applied. In addition, unlike a number of prior art devices, resistance to compression of the device is not provided by any pressure sensors but the deformable material, with the result that the device can be cheaper and more robust. Furthermore, because of the degree of deformability of the device, a single device may be appropriate for different hand sizes since it is not necessary for the user's hand to fit the device accurately or for his fingers to be in register with buttons on the device.

The force or pressure of the user' s hand may be detected in a number of ways. For example, the resiliently deformable layer may be formed from a resistive foam, for example an open cell or closed cell foam formed from a plastics material like polyurethane that is loaded with a conductive filler, for instance carbon or silver. If the core of the device is held at an electrical potential that is different to that of the surface layer, the electrical resistance between the core and the surface layer of the device will vary with the degree of compression of the deformable layer. Other forms of sensor may alternatively be employed. In general, however, it is preferred to employ proportional sensors in which the output from the sensors varies generally linearly with the strength of the field or radiation intensity.

The deformable layer may be formed from any of a number of materials, whichever of the designs of device is employed, although the particular material chosen will depend on the properties that are required for the mechanism employed to detect manipulation of the device. The layer may be foamed as described above in which case it may have a bulk modulus that is sufficiently low to enable it to be deformed by the user, for example not more than lOOkPa, preferably not more than lOkPa and especially not more than 5kPa, but usually at least lkPa. Such a modulus would, for example, allow a user to reduce the volume of the deformable material by typically 75% by applying 50 to 200N force over a contact area of the device with the user's hand of 200cm². Alternatively, the layer may be formed from a gelatinous material which, although not compressible, will deform when the device is squeezed by the user by flowing away from the points of applied force. In order to enable the material to flow sufficiently under a typical force applied by the user's hand, a gelatinous material may have a Young's modulus in the range of from 1 to 50 MPa. The relative permittivity or dielectric constant of the material may be important and is preferably in the range of from 1 to 5.

The complimentary layer is preferably electrically conductive in order to form a common electrode and/or may include a plurality of conductive elements e.g. metallic fibres, and is compliant so that it will be deformed by pressure applied by the user but will return to its original shape under the resilience of the deformable layer. It may also be stretchable at least to a limited extent so that it can be deformed in more than one direction if, for example, a point- like force is applied. This may be achieved by forming it from a conductive fabric, for example from a woven or knitted fabric that has been rendered electrically conductive by means of a coating on the fibres and/or by incorporating electrically conductive, e.g. metal, fibres therein. Typically the complementary layer will have a surface resistivity of up to 50 Qper square.

The use of a single fabric or other electrically conductive material to form a common electrode has the advantage that only a single electrical connection need be made with any wires etc to take any signal from that electrode. If on the other hand, a number of rigid elements were employed, either to form an electrode on the surface of the deformable layer or otherwise to act as detectors, a large number of electrical connections would need to be made which would necessarily be located on the deformable layer. In addition an electrical connection would need to be made with each of the elements, with the result that movement of the element on the deformable layer as the device is repeatedly squeezed could cause fatigue and possible failure of the electrical connections unless they are provided with some stress relief. It is possible to attach the complementary layer to any electrical wires at a region where the deformable layer does not move to a significant extent, or where the complementary layer is attached to a rigid part of the device.

The external surface of the device may be provided by an outer cover which can protect any sensors or elements from abrasion or other mishandling, and may provide a cosmetic surface that can be patterned if desired.

It is preferred for the wall thickness of the deformable layer to be a significant proportion of the distance from the core to the outer surface, for example at least one third of the distance and especially forming a major part of the distance. In this way a sufficient degree of movement of the sensing layer may be achieved as the device is squeezed to give the device the appropriate feel, and to ensure that the sensors will record the degree of force applied to the device accurately.

The elements employed in the core and/or in the complementary layer are preferably multiplexed so that the degree of compression of the deformable layer at a number of points around the device can be detected separately.

The number of electrically conductive elements that are employed in the array in the core or in the complementary layer may vary widely and will depend on a number of factors including the purpose for which the device is used, and the degree of spatial resolution of the applied forces required. However, it is not necessary to provide an element to detect a point of applied force of the user on every part of the surface of the device for which an indication of manually applied force is desired since the resiliently deformable layer may have a significant thickness and may therefore allow the surface of the device to move toward the core to a significant extent as the device is squeezed. This means that those parts of the surface and complementary layer adjacent to the part that is being depressed by the user will also move toward the core to a lesser extent, and so those adjacent parts of the complementary layer will also register some degree of applied force. Software may be provided in the device or in the associated computer that can interpolate the detected forces so that an indication of the degree of compression of the deformable layer between the positions of the sensors may be obtained. The minimum number of elements will normally be four, and preferably seven in order to provide at least one sensor in the region of each finger of the user. Typically the device will have at least 20 elements arranged over the surface of the core and/or deformable layer, and may in the preferred example be provided with up to 64 elements, although it is possible for even more elements to be present. The elements may be provided substantially uniformly over the entire surface of the core and/or deformable layer insofar as this is possible and depending on the shape of the device, although it is possible for the elements to be provided in a non-uniform pattern if desired. For example, it may be desired to employ more elements in the region of the device to be grasped by the user's fingers in order to enable a higher spatial resolution, and relatively few elements to be provided over those parts of the device that will be touched by the palm of the user's hand or those parts of the device that will not be grasped in use .

The device may have any of a number of shapes depending on the intended use, for example it may be rectangular or cylindrical if it is intended to be a remote control for a domestic appliance, or it may be generally spherical, prolate spherical or oblate spherical, or any other shape that can be grasped by a user's hand. The device may, for example, be generally flat, and have a shape of a rounded irregular polygon, or any other shape that is convenient for being grasped. The device preferably has a mass that will enable it to be held easily by the user, especially in the case of wireless applications. Typically the mass of the device will be in the range of from 50 to 200g. and especially from 75 to 150g.

It is possible for the resiliently deformable layer to surround the core or a rigid central part of the device entirely, that is to say over the entire surface of the core, but this is not necessary in all cases. For example, it is possible for the resiliently deformable layer to be in the form of a band that extends 360° around the core or central part, while leaving the top and bottom exposed. In addition, it is not essential for the deformable layer when in the form of a band to extend round the entire core (for 360°), but may extend only around a major part of the core or central part, and other parts of the device, for example those parts that may rest in the user's palm, may not be provided with the deformable layer.

The device may be required simply to detect compression by the user, or additional functionality may be provided, for example it may include an accelerometer, preferably a three-axis accelerometer in order to be able to detect rotational motion and/or orientation, and/or to detect linear acceleration. The device may thus form part of a six degree arrangement in which position and orientation or rotation in each of three orthogonal directions may be determined. In addition or alternatively, other means may be provided for determining for example the coordinate position or orientation of the device. For example, the device may be provided with a gyroscope to enable the orientation of the device along one axis to be established. Alternatively, three gyroscopes may oriented in orthogonal directions may be included to generate a six degree of freedom device. Orientation of the device about any axis may be determined by integrating the change in orientation. In some instances, it may not be necessary for the device to be capable of being grasped by the user but may instead have a different geometry. For example, it is possible for the device to be in the form of a cover that can be located on another object or support. Thus, according to another aspect, the invention provides a controller device for inputting hand-manipulations of a user to a computer, which comprises a resiliently deformable layer that has on one face thereof an array of electrically conductive elements, and on an opposite face thereof, a conformable complementary layer that is electrically conductive, the array of elements and the complementary layer being operable to generate an analogue output that is dependent on the separation between at least one of the elements and at least part of the complementary layer. Thus the device may have any shape that is desired. For example, it may be formed in the shape of a bag or pocket that can receive a small rigid object, for example of a size that can be gripped by a hand. Alternatively, it may be formed as a two-dimensional sheet that can be positioned on and fixed to a flat surface. As with the device according to the first aspect of the invention, the device may be provided with a detector circuit for receiving the analogue output and transferring it to a computer.

The detector circuit will normally include a microcontroller, a digital bus that is connected to sensors of the array in order for the sensors to be polled in turn to output data relating to their position relative to the core, an analogue bus for receiving output from each sensor when it is polled and for transferring the output to the microcontroller, and an interface for transferring the output from the microcontroller to the computer. The device may be operable to transfer the output from the sensors to the computer by means of a cable, or it may include a transmitter to transfer output from the sensors to the computer by wireless communication. At least in the case of wireless communication where the device may be physically separate from the computer or other equipment, the device may include a battery or terminals for connection to a battery, either a primary or secondary battery.

According to the broadest aspect of the invention, it is not essential to provide any feedback to the user relating to the degree of force applied to the device by the user although this may be preferred for many applications. The feedback may be digital, for example in the form of an audible sound when the force applied by the user exceeds a threshold, or an analogue feedback may be provided. Because the sensors provide an analogue output it may be desirable to provide an analogue feedback rather than digital feedback. This may be provided either by the controller device or, more usually, by the computer to which the device is connected. For example the feedback may be provided by a visual display from a computer to which the device is connected or it may be provided in a form that can be detected by other senses of the user. For example an audible tone may be generated whose volume or frequency may vary in dependence on the distance of any of the sensors from the core, and hence on the force with which the device is squeezed.

According to another aspect, the invention provides a user interface arrangement for a computer, which comprises a controller device according to the invention and a cradle that is adapted to receive the controller device and to supply power for the detector circuit, for example for charging any battery in the device or for supplying power inductively by a near field arrangement.

According to a further aspect, the invention provides a method of operating a computer, which comprises detecting manipulation of a controller device by a user of the computer, the controller device comprising a core that is divided into a plurality of electrically conductive elements, a resiliently deformable layer that at least partly surrounds the core, and which can be deformed by application of force by the user, and a conformable complementary layer that is located on the deformable layer, and is electrically conductive, the core and complementary layer being operable to generate an analogue output that is dependent on the separation between at least one of the elements and at least part of the complementary layer, and the device having a detector circuit for receiving the analogue output and transferring it to the computer, wherein manipulation of the controller device will cause one or more of the sensors to move toward the core so that its output is altered .

The computer to which the device is intended to be connected may be a general purpose computer or it may be an application specific device such as a computer games console or specific domestic equipment e.g. a television control.

The controller device may be employed in any of a number of applications, for example as an instrument control e.g. where precision is required such as in surgery, or the handling of dangerous materials etc. Other applications include interactive toys, gaming interfaces such as a bouncing ball for Wii applications that knows that it has been bounced. The device could be used as an e-paint brush where the user's hand pressure affects the line or colour being painted. Many other applications will be apparent to the reader.

According to another aspect, the present invention provides a controller device for inputting hand-manipulations of a user to a computer, the controller device comprising a core that is operable to generate or detect an electric or magnetic field or optical radiation, a resiliently deformable layer that surrounds the core and which can be deformed by application of force by the user's hand, a complementary layer that is located around the deformable layer and includes an array of elements that are operable to detect or to generate respectively the electric or magnetic field or optical radiation, the core and elements being operable to generate an analogue output that is dependent on the distance of the elements from the core, and the device having a detector circuit for receiving the analogue output and transferring it to the computer.

In yet a further form of the controller device, optical means may be used to determine the distance of the complementary layer from the core. For example, the core and the elements in the complementary layer may comprise one or more optical sources and optical detectors respectively, although if desired the optical sources may be provided in the complementary layer and the detectors may be provided in the core. The optical sources may conveniently be formed by light emitting diodes (LEDs) and the detectors by PiN photodiodes or phototransistors . As the source and detector move closer together, the solid angle of the source subtended by the detector increases and hence the power output by the detector increases.

References to optical radiation made herein do not necessarily imply that the radiation is in the visible region of the spectrum. The radiation may be visible, infrared or ultraviolet.

Where a number of sources or detectors are employed in the core, these are preferably connected in parallel, whereas the sources and detectors present in the complementary layer are preferably multiplexed so that the degree of compression at a number of points on the surface of the device can be detected separately .

The deformable layer may be formed from any of a number of materials, whichever of the designs of device is employed, although the particular material chosen will depend on the properties that are required for the mechanism employed to detect manipulation of the device. The layer may be foamed as described above in which case it may have a bulk modulus that is sufficiently low to enable it to be deformed by the user, for example not more than lOOkPa, preferably not more than lOkPa and especially not more than 5kPa, but usually at least lkPa . Such a modulus would, for example, allow a user to reduce the volume of the deformable material by typically 75% by applying 50 to

200N force over a contact area of the device with the user's hand of 200cm². Alternatively, the layer may be formed from a gelatinous material which, although not compressible, will deform when the device is squeezed by the user by flowing away from the points of applied force. In order to enable the material to flow sufficiently under a typical force applied by the user's hand, a gelatinous material may have a Young's modulus in the range of from 1 to 50 MPa.

The use of a gelatinous material may be advantageous in the case of a device in which optical radiation is transmitted between the core and the elements on the complementary layer since the degree of scatter of the radiation will be lower than with a foamed material. Alternatively, the scatter of radiation caused by the use of a foamed material for the deformable layer may be reduced by appropriate choice of plastics material and wavelength of the radiation such that the plastics material has a relatively low absorption at that wavelength. For example the use of translucent silicone as the plastics material with radiation at a wavelength of 300nm to 800nm will generally exhibit low scatter.

Where the device operates by detecting changes in the electric field that is generated, the relative permittivity or dielectric constant of the material may be important and is preferably in the range of from 1 to 5. Alternatively, where the device operates by detecting changes in the magnetic field, the relative permeability of the material may be important and is preferably in the range of from 0.9 to 2.

Several forms of controller devices according to the present invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a sectional elevation through a corded controller according to one aspect of the invention;

Figure 2 is a sectional elevation through another embodiment of the device that is designed for wireless communication with the computer Figure 3 is a block diagram of the sensor array and electronic circuitry of the device;

Figure 4 is a block diagram of the electronic circuitry employed in the controller of figure 1 ;

Figures 5 and 6 are sections through another form of device according to the invention;

Figure 7 is a schematic perspective view of the device of figures 5 and 6;

Figure 8 is a section through a device according to a second aspect of the invention; and

Figure 9 is a plan view of the device shown in figure 7.

Figure 10 is a modification of the device shown in figure 1 that employs a magnetic field and Hall effect sensors;

Figure 11 is a plan of flexi-rigid printed circuit board that supports the sensors of the device of figure 10;

Figure 12 is a schematic diagram showing the principle of operation of a device that employs optical radiation;

Figure 13 is a schematic diagram showing the emitter and sensor circuitry of the device referred to in figure 12; and Figure 14 is a schematic diagram showing the emitter and sensor circuitry of an alternative form of device .

Referring to figure 1 of the accompanying drawings, the controller device of figure 1 comprises a generally spherical core 70 formed from an insulating material having an array number of metal elements 72 formed thereon (or therein in the event that the core 70 is hollow) which are electrically isolated from one another. Each metal element forms one electrode so that electric field lines radiate outwardly from the core to the exterior of the device . The spherical core 70 typically has a diameter in the range of 20 to 40mm, and especially approximately 30mm, and may be provided with from 4 to 64 electrically conductive elements typically having dimensions of 0.5 to 5 mm.

Surrounding the core 70 is a generally spherical layer of resiliently deformable material 10, for example a closed cell or open cell foamed plastics material, e.g. polyurethane . The deformable material 10 has a wall thickness in the range of from 10 to 40 millimetres and will typically have a Young's modulus in the range of 0.10 to 15 MPa, to allow it to be squeezed easily by about 15 mm by the fingers of the user's hand. The deformable material 10 may be provided in the form of a pair of generally hemispherical half -shells 10a and 10b that can be positioned together to form a sphere and are each provided with a recess for receiving part of the core 2.

The resistivity of the formed material may vary with the degree to which the device is squeezed, and may comprise a polymer that is filled with a conductive or semiconductive material. Typical polymers that may be used in this aspect include neoprene with a resistivity of approximately 10 x 10⁹

Dm and polyurethane with a resistivity of approximately 1.5 x 10¹⁰ Qm. Typical fillers include carbon with a resistivity of approximately 3.5 x 10^~5 Q , silicon with a resistivity of approximately 640 Qm although the precise resitivity may be altered by doping, and metals such as silver with a resistivity of 1.6 x 10^'8 Ωιτι and iron with a resistivity of 1 x 10^"7

Ωιτι. The resistivity of the foamed material may be chosen by adjusting the degree of filling of the polymer for example to give a resistivity p in the range of from 10² to 10⁵ Qm, preferably from 10³ to 10⁴ Qm. Compression of the foam causes displacement of the air from the foam cells, and causes the electrical resistance between the central electrode and the outer electrodes to change for example due to increase in the contact area of the cells.

Around the pair of hemispheres 10a and 10b is located a conformable electrically conductive layer 12 forming a common ground electrode to each of the elements 72 of the core of the device.

The conformable layer 12 may be formed from any electrically conductive stretchable fabric. Such fabrics may be formed from stretchable fibres, for example formed from elastane or other similar stretchable material that are woven and are rendered electrically conductive by means of metal coatings or by means of incorporating metallic fibres or other elements therein. One such fabric is sold under the tradename "electrolycra" , while another fabric is sold under the tradename "electronylon" available from Middlesex University Teaching Resources, Unit 10, The 10 Centre Lea Road, Waltham Cross, Hearts, U.K. Alternatively, fabrics that incorporate metallic fibres and whose stretchability is given by being knitted, may be used.

During assembly of the device, a bonded protective PCB covering 18 is fixed to a flattened part of the deformable foamed material 10, and located adjacent a PCB supporting the electronics.

After application of the PCB, a thin secondary outer layer 22 of the compressible material may be stretch fitted over the assembly to protect the sensors and to mask any protuberances caused by them to the user. Finally, a protective outer cover 24 may be placed over the entire assembly. This outer cover may be patterned and/or include any visible information or logos to provide an acceptable cosmetic appearance and to enable customisation of the device for different users or uses. The outer cover may be provided with an elasticated cuff 26 to hold it on to the assembly. In this embodiment the PCB has a cable 28 for example a USB cable, that extends from the surface thereof opposite the foamed material, for allowing communication with the computer. The PCB 16 is fixed to, and the cable 28 is enclosed in, an electronics support or housing 30 that is designed to fit the palm of the user's hand, and includes strain relief 32 for the cable where the cable exits the housing .

Figure 2 is a sectional elevation through a second embodiment of the invention which corresponds generally to the first embodiment but which is designed for wireless communication with the computer. The device comprises a core 70, deformable layer 10, cover 24 etc which are as shown in figure 1 and will not be described further. In the device of the second embodiment a wireless board 60 is provided which includes a wireless interface 61 shown in figure 3, radio transceiver and antenna, and a battery and housing 62. The battery may comprise a primary cell or, as is preferred, a secondary cell in which case a charging contact 64 may be provided for charging the battery. RF communications may be achieved in any appropriate way, for example by means of the IEEE 802 standard (Zigbee) or by frequency hopping spread spectrum (Bluetooth) which allow 250kbps and 1Mbps respectively to be transferred to the computer.

The electronics circuitry is shown in figure 3. The circuit comprises a microcontroller unit 40 for controlling the output of the elements of the core and the common ground electrode, a three-axis accelerometer 42, a power supply 44, and a cable interface 46. The electrodes located on the core forming one of the plates of the capacitors are arranged in a number of arms radiating from one point on the core. In addition, the circuit includes the array of elements 72, a digital bus 48 for controlling the elements and an analogue bus 50 for allowing the microcontroller 40 to read the outputs. Each element has a digital enable line 52 connected thereto at the core, and an analogue output that is sent to the microcontroller via output lines 54 that form the output bus 50. When the device is disabled its analogue output goes into high impedance . The analogue outputs of the eight elements in an arm are connected together. Only one element in an arm is enabled at any given time. The enable pins of the each row of elements are connected to the same digital output of the microcontroller. Therefore to interface all the sensors to the microcontroller eight analogue input and eight digital output lines are required.

The microcontroller may also interface with a 3- axis accelerometer, whose values can be read through a digital communication bus, for example Serial Peripheral Interface (SPI) .

A power supply is needed to power the circuitry. Input power is derived from the Cable Interface, for example a Universal Serial Bus (USB) , to power the circuitry or to charge the battery of the wireless option.

Software can be divided in two areas : microcontroller software, and high-level software for the PC or other computer. The program running in the microcontroller has two functions, namely to scan all the sensor information and log it in RAM, and to transfer sensor information to the computer through the USB. Therefore the microcontroller must be capable of enumerating and negotiating with a USB host and running a USB stack. It is assumed that some parts of the USB software may be available through the microcontroller vendor. A scan of all capacitors is needed with possible moving average filter. After scanning for the capacitors the microcontroller reads the values of the accelerometer and updates its registers .

The PC software comprises the USB drivers for the device and a User Interface to retrieve the information and display it.

The data is configured in a matrix of Θ and φ using spherical coordinates, where Θ and φ are the azimuth and inclination angles respectively.

φ= 16.7 φ =33.3 φ =50 φ =66.7 φ =83.4 φ = 100 φ =1 16.7 φ = 133.4 θ=0

θ =45

0 =90

θ =135

θ = 180

θ =225

θ =270

θ =315

The scanning order is from cp=16.67, θ=0, to φ=16.67, θ=315, followed by φ=33.3, θ=0, to φ=33.3, θ=315 and so on up to φ=133.4, θ=0, to φ=133.4, θ=315. Data is transferred from the microcontroller to the computer in the same order. After the data from the capacitors has been transferred the accelerometer information follows in the order X-Y-Z axes. Information obtained from the capacitors is converted into the distance of the conformable fabric with respect to the core, which can then be used to estimate the amount of pressure applied to the manipulator. A total of 67 bytes of data need to be transferred to the host device. Allowing twice the number of bytes for overhead and cyclic redundancy check (CRC) gives a total of 134 bytes forming each data frame. A frame is transferred at least every

10ms, to give a minimum data rate of 107.2kbps.

USB allows operation at Low Speed of 1.2Mbps, therefore is enough bandwidth to transmit a frame and even achieve faster refresh rates. The user will be capable of using the device without any visual feedback besides his direct influence. The device will be able to detect variations in position of the surface caused by the user, rotation relative to vertical (i.e. elevation angle) and user gestures consisting of movement patterns causing accelerations > O.Olg in any direction. The interface output can be turned on or off by either an external signal (e.g. magnetic cradle) or a specific user input. The interface will provide visual feedback if required, informing the user of gestures performed, device positioning, compression and mode of operation (if applicable) as requested.

A circuit that may be employed to sense changes in the electrical resistance of the filled material 10 between the electrodes of the detector is shown in figure 4. In this circuit, electrodes 72 that are connected to the core 70 of the device by means of the filled polymer material 10 are output to an analogue multiplexer 90 that takes the voltage on each of the electrodes 72 in turn. The resistance change of the filled material 10 may be relatively small, and so it may be desirable to have a precision measurement, in which case the output of the multiplexer is sent to a wheatstone bridge 92. The middle points of the bridge are connected to a differential amplifier 94, and the output of the differential amplifier is passed to an analogue channel of the microcontroller 84. The sensed voltage is given by:

Vcc R - Rs ^~

Vsense =

R + Rs

Provided R > Rs for all deformations then Vsense always positive. If we now let

Rs = R + Mc then,

2R Vsense

ARc =

Vsense + Vcc 12 Now a relationship between compression and change of resistance, ARc, can be found empirically.

Figure 5 is a schematic sectional elevation through a further design of controller device according to the invention, and figure 6 is an enlarged view of part of the device. This device has a relatively large rigid central portion 100 that houses any electronics, accelerometers , wireless communications equipment etc and a deformable region 102 that extends around the edge of the rigid central region but leaves the top and bottom of the central region exposed. Within the deformable region 102 a core 104 extends around the central region. The core 104 has a half-cylindrical form having a semi-circular cross-section that is oriented in a direction away from the rigid central portion 100. The outer surface of the core is divided into a number of small copper pads 106 of approx. 2mm size that are electrically isolated from one another and which form a number of electrodes. The core 104 is surrounded by the layer of deformable material 102, for example an open-cell foam, of generally constant wall-thickness , on which is located a conformable electrically conductive fabric 108 as described above which forms a common electrode for the capacitors. An electrical connection to the fabric may be provided on the rigid central portion 100. Around the fabric an outer cover is provided to protect the conductive fabric and other parts of the device. Figure 8 is a schematic view of the entire controller device. In this design of controller device, the deformable portion extends over only approximately 50 to 60% of the device, and the maximum surface displacement of the deformable portion will be approximately 4 to 5mm.

Figures 8 and 9 show an alternative form of controller device according to the invention, with figure 8 being a cross-section through part of the device (not showing the edge regions) and figure 10 being a top plan view.

This device comprises a lower rigid two- dimensional plate- like surface 120 on which is located an array of rectangular, e.g. square, metallic pads 122 each forming one element. Over the metallic pads, a deformable layer 124 of conductive foamed material is provided, followed by a conductive fabric 126 which is grounded and which provides the complementary electrode . A further cover layer may be provided on top of the conductive fabric in order to protect it and provide any abrasion resistance. This form of device may be positioned on a flat horizontal surface used as a flat two-dimensional controller for a computer . A further form of device is shown in figure 10. A generally spherical input device 1 for a computer comprises a core 2 comprising a generally cubic magnet holder 4 and a number of permanent magnets 6 for generating a magnetic field that radiates outwardly from the core 2 to the surface of the device . In this case the magnets are N42 Neodymium- Iron-Boron (NdFeB) magnets, and six magnets 6 are arranged with the centre of each magnet arranged octahedrally at the centre of each face of the cubic magnet holder with the same pole, either north or south seeking, of the four horizontal magnets facing outwards and the opposite pole of the top and bottom magnets facing outward. Other arrangements of magnets may be employed as appropriate .

Surrounding the core 2 is a generally spherical layer of resiliently deformable material 10, for example a closed cell or open cell foamed plastics material, e.g. polyurethane . The deformable material 10 has a wall thickness in the range of from 10 to 40 millimetres and will typically have a Young' s modulus in the range of 0.10 to 15 MPa, to allow it to be squeezed easily by about 15 mm by the fingers of the user's hand. The deformable material 10 may be provided in the form of a pair of generally hemispherical half-shells 10a and 10b that can be positioned together to form a sphere and are each provided with a recess for receiving part of the core 2.

An array of 64 Hall effect sensors 12 are disposed about the outer surface of the deformable material . Eight sensors are arranged along each of eight arms 14 of flexible PCB, formed for example from polyamide or polyimide, that radiate outwardly from a central part 16 of rigid PCB formed for example from FR4 that supports the various electronics components of the device, and is bonded to the lower half-shell 10b of foamed material by means of a protective PCB covering. Preferably, a stiffener layer is placed underneath each sensor 12 after population to improve the reliability of any solder joints. During assembly of the device, a bonded protective PCB covering 18 is fixed to a flattened part of the deformable foamed material 10, and the arms 14 are folded around the foamed material so that each arm extends approximately half way around the sphere of material. The ends of the arms opposite the rigid PCB are held together by means of a fastener 27.

After application of the PCB with the sensors, a thin secondary outer layer 22 of the compressible material may be stretch fitted over the assembly to protect the sensors and to mask any protuberances caused by them to the user. Finally, a protective outer cover 24 may be placed over the entire assembly. This outer cover may be patterned and/or include any visible information or logos to provide an acceptable cosmetic appearance and to enable customisation of the device for different users or uses. The outer cover may be provided with an elasticated cuff 26 to hold it on to the assembly. In this embodiment the PCB has a cable 28 for example a USB cable, that extends from the surface thereof opposite the foamed material, for allowing communication with the computer. The PCB 16 is fixed to, and the cable 28 is enclosed in, an electronics support or housing 30 that is designed to fit the palm of the user's hand, and includes strain relief 32 for the cable where the cable exits the housing .

The electronics circuitry may generally be as described above with reference to figure 3. This form of device may be modified so that it is cordless in the same manor as the device described above and shown in Figure 2.

In yet a further embodiment, the device may have the general configuration as shown in figure 1 but in which the core 70 may comprise one or more optical radiation sources for example in the form of LEDs and the elements 72 comprise opto sensors for example in the form of PiN diodes for receiving the radiation. The principle of operation of this form of device is as follows:

In the case of a Lambertian source, which is by- definition one whose radiance is completely independent of viewing angle, radiation is emitted uniformly into a solid angle of 2π str (steradians) as shown in figure 12. In reality sources such as LEDs are not Lambertian sources but can be made to approximate one by conditioning, as described below.

In the case of a circular detector D with an active area of ^r_rf ²where r_rfis the radius of the active area, for an approximately normal viewing angle, where Θ tends to 0°, the power detected by the detector, P_D , at a distance R from the source is given by:

ι·^π , where p

s is the source power (W) ^^D is the solid angle of light accepted by the

Ω_β = 4^· sin'

detector, ,2, a is the half angle of the cone

OD is given by the equation a

Ω_η = 4;rsin²

2 2R (_rads)

Therefore for a given detector radius the power

1

detected ^QC

R²

Most sources are, however, not Lambertian and will require the light to be conditioned using diffusers etc. To achieve a Lambertian source to illuminate the inside of a sphere it is likely to require multiple sources, for example six sources located around a cube forming the core and careful homogenisation using controlled diffusers (e.g. holographic)

The detection process may be complicated by beam overlap/non- conformity and viewing angle. The beam overlap/non-conformity may be addressed by only illuminating a single source at a time and sweeping around all the sources in the matrix. In both cases the emitters could be switched individually so that the location of the light source is known.

The use of IR LEDs and PiN diodes may have several advantages if deployed as a transducer in view of their small physical size, low cost and fast switching.

In order to improve the coupling of the radiation source and detectors it may be desirable for the resiliently deformable layer to be translucent, at least at the wavelength of the radiation employed by the LEDs and PiNs, for example in the form of a gel. The gel maintains constant volume and therefore the elastic shell expands under squeezing in certain areas, providing resistance to the squeezing input. This gel could also have a light scattering characteristic to homogenise the light if the solution was to have a uniform light level.

The electronic circuitry for this form of controller device may be as shown in figure 13. Six optoemitters (LEDs) 94 are connected in parallel with a current source 96 delivering a current I_L. The sensing circuit may be formed by a number of phototransistors 98 that are multiplexed by means of an analogue multiplexer 100 so that the output from each sensor occurs in one timeslot of the multiplexer.

The output is amplified and sent to the microcontroller .

Alternatively, if desired, the optoemitters may be located on the exterior part of the device within the complementary layer shown by the figure 72, and the optosensors or sensing elements may be located at the core of the device. The circuitry as shown in figure 10 may be employed in this form of device in which the driving current for the optoemitters may be demultiplexed by an analogue demultiplexer before driving the emitters. A number (six in this case) of optosensors in the form of optotransistors located at the core of the controller device may be connected in parallel, and their output is amplified and sent to the microcontroller.

Claims

Claims :

1. A controller device for inputting hand- manipulations of a user to a computer, the controller device comprising a core or support, a resiliently deformable layer that at least partly surrounds the core or support and which can be deformed by application of force by the user, the deformable layer comprising a resistive foam having an electrical resistivity that varies in dependence on the degree of compression of the foam, and the device including a conformable complementary layer that is located on the deformable layer and is electrically conductive or has a plurality of conductive elements therein, the core or support and complementary layer being operable to generate an analogue output that is dependent on the distance of the complementary layer from the core and the device having a detector circuit for receiving the analogue output and transferring it to the computer.

2. A controller device as claimed in claim 1 wherein the core or support is divided into a plurality of electrically conductive elements, and the analogue output is dependent on the separation between at least one of the elements in the core and at least part of the complementary layer.

3. A controller device as claimed in claim 1 or claim 2, wherein the foam comprises a plastics material that is loaded with electrically conductive particles .

4. A controller device as claimed in any preceding claim, wherein the resiliently deformable layer extends at least partly around the core, and the device includes one or more substantially rigid regions that form part of the surface of the device.

5. A controller device as claimed in claim 4, wherein the resiliently deformable layer is in the form of an annulus that extends round a subs antially rigid central region.

6. A controller device as claimed in any preceding claim, wherein the resiliently deformable layer is generally flat and is located on the support, and the complementary layer is located on the opposite side of the resiliently deformable layer to the support to form a generally flat, two-dimensional device.

7. A controller device as claimed in any one of claims 1 to 6 , wherein the output of the elements is multiplexed .

8. A controller device as claimed in any one of the preceding claims, which includes an outermost layer that encloses the complementary layer.

9. A controller device as claimed in any one of the preceding claims, wherein a major part of the distance from the core to the external surface of the device comprises the deformable layer.

10. A controller device as claimed in any preceding claim, which includes at least seven elements.

11. A controller device as claimed in claim 10, which includes at least 20 elements.

12. A controller device as claimed in any one of the preceding claims, which includes an accelerometer .

13. A controller device as claimed in claim 12, which includes a three axis accelerometer.

14. A controller device as claimed in any preceding claim, which includes a gyroscope.

A controller device as claimed in claim 14, which ludes three orthogonally oriented gyroscopes.

16. A controller device as claimed in any one of the preceding claims which includes a transmitter to transfer output from the detector circuit to the computer by wireless communication

17. A controller device as claimed in any one of the preceding claims, wherein the detector circuit comprises a microcontroller, a digital bus that is connected to sensors of the array in order for the sensors to be polled, an analogue bus for receiving output from each sensor when it is polled and for transferring the output to the microcontroller, and an interface for transferring the output from the microcontroller to the computer.

18. A user interface arrangement for a computer, which comprises a controller device as claimed in any preceding claim, and a cradle that is adapted to receive the controller device and to supply power for the detector circuit .

19. A system which comprises a computer and a controller device as claimed in any one of claims 1 to 17 or a user interface as claimed in claim 18 connected thereto.

20. A method of operating a computer, which comprises detecting manipulation of a controller device as claimed in any preceding claim by a user of the computer .

21. A controller device for inputting hand- manipulations of a user to a computer, the controller device comprising a core that is operable to generate or detect an electric or magnetic field or optical radiation, a resiliently deformable layer that surrounds the core and which can be deformed by application of force by the user's hand, a complementary layer that is located around the deformable layer and includes an array of elements that are operable to detect or to generate respectively the electric or magnetic field or optical radiation, the core and elements being operable to generate an analogue output that is dependent on the distance of the elements from the core, and the device having a detector circuit for receiving the analogue output and transferring it to the computer.

22. A controller device for inputting hand- manipulations of a user to a computer, the controller device comprising a core that is operable to generate or detect optical radiation, a complementary layer that is located around the core and spaced apart therefrom and includes an array of elements that are operable to detect or to generate respectively the optical radiation, the core and elements being operable to generate an analogue output that is dependent on the distance of the elements from the core, and the device having a detector circuit for receiving the analogue output and transferring it to the computer .