Abstract: An apparatus including a touch sensitive screen having a face adapted to receive a user's hand-writing via a hand-held stylus. The screen includes means exciting the screen to vibrate so as to transmit the vibration to the stylus to simulate the sensation of a writing implement writing on paper as the stylus is moved over the face of the screen. The apparatus may include means for period modulating the electrical signal applied to the exciting means and means for amplitude modulating the electrical signal. The apparatus may include means for sensing the velocity of movement of the stylus over the screen face and means for modulating the vibration according to the sensed velocity.

Abstract: There is disclosed a method of designing a panel assembly for a vibratory panel device, the assembly comprising a panel which supports vibrations and two or more transducers coupled to the panel to transmit vibrations to or receive vibrations from the panel. The method comprises: obtaining the number of transducers to be used in the assembly and their relative positions; obtaining relationships between drive signals to be applied to the respective transducers to provide a desired effect; determining an optimisation criterion for the assembly that depends on the obtained relationships; and determining one or more parameters for the respective transducers that satisfy the optimisation criterion. The one or more parameters may be selected from amplitudes of drive signals, spacing, activity, area, position, shape, dimension.

Abstract: A transducer (140) having a mechanical impedance over an operative frequency range and having a desired power coupling (145) to a load over the operative frequency range comprises a piezoelectric device (141) having a frequency distribution of modes in the operative frequency range; and an overmould (143). The overmould (143) is arranged to surround at least part of the piezoelectric device (141); and the parameters of the overmould (143) are selected to provide a required impedance matching between the mechanical impedance of the transducer (140) and the mechanical impedance of the load. An alternative transducer comprises a mounting means for holding a discrete portion of at least a part of the periphery of the piezoelectric device wherein the parameters of the mounting means are selected to provide a required boundary condition for the periphery of the piezoelectric device whereby the desired power coupling between the transducer and the load is provided.

Abstract: There is disclosed a method of designing a panel assembly for a vibratory panel device, the assembly comprising a panel which supports vibrations and two or more transducers coupled to the panel to transmit vibrations to or receive vibrations from the panel. The method comprises: obtaining the number of transducers to be used in the assembly and their relative positions; obtaining relationships between drive signals to be applied to the respective transducers to provide a desired effect; determining an optimisation criterion for the assembly that depends on the obtained relationships; and determining one or more parameters for the respective transducers that satisfy the optimisation criterion. The one or more parameters may be selected from amplitudes of drive signals, spacing, activity, area, position, shape, dimension.

Abstract: A method of calibrating a touch sensitive device comprising a touch-sensitive screen; a plurality of transducers mounted to the screen and a processor, the method comprising inputting a signal into the screen at a test position on the screen whereby the screen is excited into vibration; detecting vibration in the screen using the plurality of transducers; and processing, in the processor of the touch-sensitive device, the detected vibration to generate an output signal for each of the plurality of transducers whereby when the transducers are driven by the output signals the screen is excited to generate a desired haptics sensation at the test position.

Abstract: A touch sensitive device including a panel capable of supporting bending waves, a user-accessible touch sensitive screen on or forming part of a face of the panel, the touch sensitive screen having a plurality of different sensing areas, a plurality of vibration exciters coupled to the panel to apply bending waves to the panel to provide tactile feedback at the plurality of sensing areas in response to the user touching a sensing area, and signal processing means arranged to apply signals to the vibration exciters so as to steer bending waves applied to the panel by the plurality of vibration exciters whereby the amplitude of the applied bending waves is maximized at the sensing area touched by the user and reduced or minimized at each other sensing area.

Abstract: There is disclosed a method of designing a panel assembly for a vibratory panel device, the assembly comprising a panel which supports vibrations and two or more transducers coupled to the panel to transmit vibrations to or receive vibrations from the panel. The method comprises: obtaining the number of transducers to be used in the assembly and their relative positions; obtaining relationships between drive signals to be applied to the respective transducers to provide a desired effect; determining an optimisation criterion for the assembly that depends on the obtained relationships; and determining one or more parameters for the respective transducers that satisfy the optimisation criterion. The one or more parameters may be selected from amplitudes of drive signals, spacing, activity, area, position, shape, dimension.

Abstract: A method of generating a keyboard switch haptic sensation in a coupled system comprising a touch-sensitive surface and a force exciter or actuator coupled to the touch-sensitive surface, the method comprising generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system, modulating the carrier wave signal with a modulation envelope so that the modulated carrier wave signal has a closely spaced pair of peaks, and driving the exciter or actuator with the modulated carrier wave signal to excite the touch-sensitive surface to provide a closely spaced pair of impulses whereby the keyboard switch haptic sensation is simulated to a user touching the touch-sensitive surface.

Abstract: There is disclosed a method of designing a panel assembly for a vibratory panel device, the assembly comprising a panel which supports vibrations and two or more transducers coupled to the panel to transmit vibrations to or receive vibrations from the panel. The method comprises: obtaining the number of transducers to be used in the assembly and their relative positions; obtaining relationships between drive signals to be applied to the respective transducers to provide a desired effect; determining an optimisation criterion for the assembly that depends on the obtained relationships; and determining one or more parameters for the respective transducers that satisfy the optimisation criterion. The one or more parameters may be selected from amplitudes of drive signals, spacing, activity, area, position, shape, dimension.

Abstract: A touch sensitive device comprising a panel capable of supporting bending waves, a user-accessible touch sensitive screen on or forming part of a face of the panel, the touch sensitive screen having a plurality of different sensing areas, a plurality of vibration exciters coupled to the panel to apply bending waves to the panel to provide tactile feedback at the plurality of sensing areas in response to the user touching a sensing area, and signal processing means arranged to apply signals to the vibration exciters so as to steer bending waves applied to the panel by the plurality of vibration exciters whereby the amplitude of the applied bending waves is maximised at the sensing area touched by the user and reduced or minimised at each other sensing area.

Abstract: A transducer (140) having a mechanical impedance over an operative frequency range and having a desired power coupling (145) to a load over the operative frequency range comprises a piezoelectric device (141) having a frequency distribution of modes in the operative frequency range; and an overmould (143). The overmould (143) is arranged to surround at least part of the piezoelectric device (141); and the parameters of the overmould (143) are selected to provide a required impedance matching between the mechanical impedance of the transducer (140) and the mechanical impedance of the load. An alternative transducer comprises a mounting means for holding a discrete portion of at least a part of the periphery of the piezoelectric device wherein the parameters of the mounting means are selected to provide a required boundary condition for the periphery of the piezoelectric device whereby the desired power coupling between the transducer and the load is provided.

Abstract: There is provided a method of generating a desired haptic sensation and providing a desired touch sensitivity in a touch sensitive device, the touch sensitive device comprising a touch sensitive member and at least one transducer connected to the touch sensitive member, the method comprising: processing electrical signals to be applied to one or more of said at least one transducer connected to the touch sensitive member by applying appropriate algorithms to provide the desired haptic sensation; and processing electrical signals from one or more of said at least one transducer connected to the touch sensitive member by applying the said appropriate algorithms to generate output signals to provide the desired touch sensitivity.

Abstract: A touch sensitive device comprising a panel capable of supporting bending waves, a user-accessible touch sensitive screen on or forming part of a face of the panel, the touch sensitive screen having a plurality of different sensing areas, a plurality of vibration exciters coupled to the panel to apply bending waves to the panel to provide tactile feedback at the plurality of sensing areas in response to the user touching a sensing area, and signal processing means arranged to apply signals to the vibration exciters so as to steer bending waves applied to the panel by the plurality of vibration exciters whereby the amplitude of the applied bending waves is maximized at the sensing area touched by the user and reduced or minimized at each other sensing area.

Abstract: There is provided a method of generating a primary effect in a vibratory panel device comprising at least N+M transducers connected to a panel, where N and M are integers greater than or equal to 1. Each transducer is electrically connected to signal processing circuitry and the signal processing circuitry is configured to receive signals from or provide signals to each transducer. The method comprises: obtaining N electrical signals to be applied respectively to N of the transducers to produce the primary effect; and processing the N electrical signals to produce M additional electrical signal(s), such that when the M signal(s) are applied to respective transducers other than the N transducers, a secondary effect is produced. The secondary effect may be for example cancellation of any audio output resulting from providing haptic feedback.

Abstract: A touch sensitive device comprising a touch sensitive display member capable of supporting bending wave vibration and having a user accessible display surface, an array of transducers coupled to the display member with the array of transducers comprising at least some transducers which are configured to both detect physical touching of the input surface by the user and to input impulses into the display member to produce a haptics sensation to the user in response to said detected touching of the display surface, and a signal processor to receive signals from at least some of transducers in the array of transducers and adapted to analyze the signals to determine the location of the physical touch on the display surface.

Abstract: A panel for use in a vibratory panel device comprises a substrate, a layer of electroactive material applied to the substrate and a layer of material applied to the electroactive material forming separate active areas whereby signals may be applied to or received from respective areas of the electroactive material, wherein the layer of material forming the active areas forms at least three active areas comprising at least two primary active areas and at least one secondary active area, the secondary active area being positioned relative to the two primary active areas such that one or both of the following conditions is provided: at least one secondary active area can be driven to at least partially offset any net displacement of the panel caused by driving two of the primary active areas; and the at least one secondary active area can sense vibrations of the panel affecting both of the two primary active areas.

Abstract: A method of generating a keyboard switch haptic sensation in a coupled system comprising a touch-sensitive surface and a force exciter or actuator coupled to the touch-sensitive surface, the method comprising generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system, modulating the carrier wave signal with a modulation envelope so that the modulated carrier wave signal has a closely spaced pair of peaks, and driving the exciter or actuator with the modulated carrier wave signal to excite the touch-sensitive surface to provide a closely spaced pair of impulses whereby the keyboard switch haptic sensation is simulated to a user touching the touch-sensitive surface.

Abstract: The invention relates to a method of making an actuator comprising a plurality of force elements and an actuator made according to the method. The method comprises providing a coupler for coupling force from the force elements to a load; calculating a transfer function for each force element wherein the transfer functions allow the force provided to the load to be predicted; determining an error functional which is indicative of any undesired dips in the predicted force; calculating the parameters of the force elements which minimize the error functional, and coupling force elements having the calculated parameters to the coupler to make the actuator.

Abstract: An acoustic device and method of making said acoustic device. The acoustic device comprises a diaphragm having resonant bending wave modes in the operating frequency range, and a plurality of electromechanical transducers coupled to the diaphragm. The positioning and mechanical impedance of the transducers are such that at least a selected number of the resonant bending wave modes are balanced so that the net transverse modal velocity over the area of the diaphragm tends to zero with the balancing of the resonant bending wave modes being achieved substantially by the positioning and mechanical impedance of the transducers. The parameters of the diaphragm may be such that there are a plurality of nodal grouped locations at or around which the nodal lines of a selected number of resonant modes are clustered. Each transducer may be mounted at one of the plurality of nodal grouped locations.

Abstract: A touch sensitive device comprising a touch sensitive display member capable of supporting bending wave vibration and having a user accessible display surface, an array of transducers coupled to the display member with the array of transducers comprising at least some transducers which are configured to both detect physical touching of the input surface by the user and to input impulses into the display member to produce a haptics sensation to the user in response to said detected touching of the display surface, and a signal processor to receive signals from at least some of transducers in the array of transducers and adapted to analyse the signals to determine the location of the physical touch on the display surface.