Tt Electronics Technology Limited

Sensopad Limited

Btg International Limited

Colin Stuart Sills

Mark Anthony Howard

David Alun James

Darran Kreit

Ross Jones

Timothy S Norris

Victoria Ann Clark

Richard Alan Doyle

Richard Allen Doyle

Darran Kriet

There is described an apparatus which monitors the orientation of or the rotational movement of a substantially spherical body. The apparatus comprises a substantially spherical body with at least one resonant circuit fixed thereto. A transmit aerial generates an alternating magnetic field in the region of space including the spherical body which induces an electric signal in the or each resonant circuit, and a receive aerial receives an induced sense signal generated in response to said induced electric signal in the or each resonant circuit. The electromagnetic coupling between the transmit aerial and the receive aerial via the or each resonant circuit varies in accordance with the orientation of the spherical body so that the induced sense signal in the receive aerial varies in accordance with the orientation of the spherical body.

Sensing apparatus and method

A sensor for sensing a parameter such as position, comprises: (i) an excitation winding for example coils () in quadrature; (ii) a signal generator () operable to generate an excitation signals and arranged to apply the generated excitation signal to the excitation winding; (iii) a sense coil () that can be electromagnetically coupled to the excitation winding such that, in response to the excitation signal being applied to the excitation winding by the signal generator, a periodic electric signal is generated in the sense coil that is indicative of the value of the parameter to be measured by the sensor; and (iv) a signal processor () operable to process the periodic electric signal generated in the sensor winding to determine a value representative of the parameter being measured. The signal processor may be arranged to generate a second signal (f) at a frequency slightly different from that of the excitation signal, and to mix the second signal with the signal received from the sense coil to generate a third signal having a frequency component (f&#x2212;f) equal to the difference between the frequency of the excitation signal and that of the second signal. The processing unit then determines the parameter from the phase of the third signal.

There is described a sensing apparatus comprising first and second members which are supported relative to each other by a support means. The first member comprises a magnetic field generator for generating a magnetic field and the second member comprises an aerial for monitoring the magnetic field generated by the magnetic field generator. At least one of the first and second members is locally deformable relative to the other of the first and second members in order to vary at least one of the magnetic field generated by the magnetic field generator and the electromagnetic coupling between the magnetic field generator and the receive aerial so that, in response to a local deformation, a signal is induced in the receive aerial indicative of the position of the local deformation.

There is described a sensor comprising an excitation winding, a signal generator operable to generate an excitation signal and arranged to apply the generated excitation signal to the excitation winding, a sensor winding electromagnetically coupled to the excitation winding and a signal processor operable to process a periodic electric signal generated in the sensor winding when the excitation signal is applied to the excitation winding by the signal generator to determine a value of a sensed parameter. The excitation signal comprises a periodic carrier signal having a first frequency modulated by a periodic modulation signal having a second frequency, the first frequency being greater than the second frequency. In this way, the sensor is well suited to using digital processing techniques both to generate the excitation signal and to process the signal induced in the sensor windings. In an embodiment, the sensor is used to detect the relative position of two members. In other embodiments, the sensor is used to detect environmental factors such as temperature and humidity.

There is described an inductive position sensor in which a signal generator applies a excitation signal to an excitation winding formed on a first member, the excitation winding being electromagnetically coupled to at least two resonant circuits formed on a second member which are spaced from each other along a measurement path. The excitation windings are shaped so that the electromagnetic coupling between the exciting winding and each of the resonators varies along the measurement path. In this way, by applying an excitation signal to the excitation winding, respective different signals are induced in the resonators which depend upon the relative position of the first and second members.

Position sensing apparatus and method

There is described a position sensor comprising at least one planar substrate having formed thereon a magnetic field generator which comprises conductive tracks formed on at least two planes defined by the at least one planar substrate. An intermediate coupling element is operable to move relative to the at least one planar substrate along a measurement direction transverse to the planar substrate, the detector detects the position of the intermediate coupling element in a magnetic field generated by the magnetic field generator. The position sensor has particular application in man-machine interfaces such as push buttons and rotary switches.

A combination magnetic tag () is described comprising an optical part () and a magnetic part (), the optical part including a plurality of optical elements for conveying an optical code and the magnetic part including a plurality of magnetic elements for conveying a magnetic code, the optical and magnetic codes being mutually complementary for verifying authenticity of the tag (). Incorporation of both optical and magnetic codes into the tag is of advantage in that they are capable of rendering the tag less susceptible to copying. The tag () is relevant to appropriate to anti-counterfeiting applications.

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Cambridge, United Kingdom

Colin Stuart Sills