Abstract: A touch sensitive device comprising a touch surface, a force exciter coupled to the touch surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch surface and exciter together forming a coupled system and a signal generator to generate the signal, with the signal generator generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system and modulating the carrier wave signal with a complex modulation where the modulated carrier wave signal has a time response comparable to that of a low frequency signal which produces a desired haptic sensation whereby a user touching the touch surface excited by the exciter in response to the modulated carrier wave signal experiences the desired haptic sensation which is perceived at a frequency below the frequency bandwidth of the coupled system.

Abstract: A touch sensitive device comprising a touch surface, a force exciter coupled to the touch surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch surface and exciter together forming a coupled system and a signal generator to generate the signal, with the signal generator generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system and modulating the carrier wave signal with a complex modulation where the modulated carrier wave signal has a time response comparable to that of a low frequency signal which produces a desired haptic sensation whereby a user touching the touch surface excited by the exciter in response to the modulated carrier wave signal experiences the desired haptic sensation which is perceived at a frequency below the frequency bandwidth of the coupled system.

Abstract: A touch sensitive device comprising a touch surface, a force exciter coupled to the touch surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch surface and exciter together forming a coupled system and a signal generator to generate the signal, with the signal generator generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system and modulating the carrier wave signal with a complex modulation where the modulated carrier wave signal has a time response comparable to that of a low frequency signal which produces a desired haptic sensation whereby a user touching the touch surface excited by the exciter in response to the modulated carrier wave signal experiences the desired haptic sensation which is perceived at a frequency below the frequency bandwidth of the coupled system.

Abstract: A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising analyzing the mechanical and electromechanical coupled system represented by the data entry screen and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

Abstract: A touch sensitive device comprising a touch surface, a force exciter coupled to the touch surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch surface and exciter together forming a coupled system and a signal generator to generate the signal, with the signal generator generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system and modulating the carrier wave signal with a complex modulation where the modulated carrier wave signal has a time response comparable to that of a low frequency signal which produces a desired haptic sensation whereby a user touching the touch surface excited by the exciter in response to the modulated carrier wave signal experiences the desired haptic sensation which is perceived at a frequency below the frequency bandwidth of the coupled system.

Abstract: A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising analysing the mechanical and electromechanical coupled system represented by the data entry screen and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

Abstract: A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising analyzing the mechanical and electromechanical coupled system represented by the data entry screen and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

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 user/machine interface comprising a panel having a surface, the panel being capable of supporting bending waves, a touch-sensitive input device associated with the surface, and means including a force transducer for providing force feedback to the input device. The force is in the form of pulses to the panel, the pulses being in the form of a modulated signal shaped as a damped sinusoid whereby a button click sensation is provided to the user's finger tip. The modulated signal may be produced by a narrow-band sine wave having a carrier frequency in the range 150 to 750 Hz and being of a duration of at least 10 ms.

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.

Abstract: A touch sensitive device comprising a touch surface, a force exciter coupled to the touch surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch surface and exciter together forming a coupled system and a signal generator to generate the signal, with the signal generator generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system and modulating the carrier wave signal with a complex modulation where the modulated carrier wave signal has a time response comparable to that of a low frequency signal which produces a desired haptic sensation whereby a user touching the touch surface excited by the exciter in response to the modulated carrier wave signal experiences the desired haptic sensation which is perceived at a frequency below the frequency bandwidth of the coupled system.

Abstract: A method of making a touch-sensitive data entry screen of the kind arranged to provide haptic response to a user via at least one electromechanical exciter coupled to the screen, comprising analysing the mechanical and electromechanical coupled system represented by the data entry screen and the at least one exciter, and selecting values of parameters of the coupled system to provide a required displacement and acceleration of the screen at low frequency in response to human touch.

Abstract: A user/machine interface comprising a panel having a surface, the panel being capable of supporting bending waves, a touch-sensitive input device associated with the surface, and means including a force transducer for providing force feedback to the input device. The force is in the form of pulses to the panel, the pulses being in the form of a modulated signal shaped as a damped sinusoid whereby a button click sensation is provided to the user's finger tip. The modulated signal may be produced by a narrow-band sine wave having a carrier frequency in the range 150 to 750 Hz and being of a duration of at least 10 ms.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.

Abstract: From one aspect, the invention is a method of making a bending wave panel loudspeaker, comprising rigidly coupling a lever to a panel edge or marginal portion such that the lever extends at an angle to the plane of the panel, coupling a bending wave exciter to the lever whereby bending wave energy is coupled to the panel to produce an acoustic output when the exciter is fed with a signal and supporting the panel on a suspension positioned outboard of the lever. From another aspect the invention is a bending wave panel-form loudspeaker having a lever rigidly coupled to a marginal portion or edge of the panel, a vibration exciter coupled to the lever to apply bending wave energy to the panel to produce an acoustic output and a panel suspension positioned outboard of the lever. From a further aspect, the invention is a small electronic device, e.g.

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 bending wave loudspeaker having an operating frequency range and a coincidence frequency which is above the operating frequency range, comprising a resonant panel having two generally orthogonal axes, vibration exciting means coupled to the panel to excite the panel into resonance along the one axis of the panel, and means restraining or preventing resonance along the other axis of the panel whereby the panel radiates an acoustic output which is of wide directivity along the one axis and of narrow directivity along the other axis of the panel.

Abstract: An inertial exciter (40) for an acoustic radiator (42), and a loudspeaker incorporating an acoustic radiator and such an exciter. The exciter has a massive member (44); a coupler (56) adapted for attachment to the acoustic radiator (42) and adapted for relative movement with respect to the massive member (44); a motor for effecting relative movement of the coupler with respect to the massive member; and a suspension (60) for supporting the massive member relative to the coupler. The suspension (60) acts in a plane generally passing through the center of mass of the massive member, thereby reducing any moment acting on the suspension. Also disclosed is a loudspeaker exciter assembly (70) that has a base plate (86) for attachment to an acoustic radiator in a non-repeatedly engageable manner, and an exciter (40) attached to the base plate (86) in a repeatedly engageable manner; and a loudspeaker incorporating such an exciter assembly.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.