Touch sensitive device
AssigneeNew Transducers Limited
InventorNeil John Harris
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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.
Claims23
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 comprising a first peak and a second peak, 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 pulses whereby the keyboard switch haptic sensation is simulated to a user touching the touch-sensitive surface,
- wherein the modulation envelope comprises a sum of two exponential functions having different decay rates so that the modulated carrier wave signal has the closely spaced pair of peaks.
A touch sensitive device comprising
- a touch-sensitive surface,
- a force exciter coupled to the touch-sensitive surface to excite vibration in the surface in response to a signal sent to the exciter, with the touch-sensitive 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 modulation envelope so that the modulated carrier wave signal has a closely spaced pair of peaks whereby a user touching the touch-sensitive surface excited by the exciter in response to the modulated carrier wave signal experiences a keyboard switch haptic sensation,
- wherein the modulation envelope comprises a sum of two exponential functions having different decay rates so that the modulated carrier wave signal has the closely spaced pair of peaks.
Dependencies are inferred from the claim text.