Method and apparatus for modulating haptic feedback
The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.
1. A method comprising:
creating a pressure pattern with a plurality of transducers using ultrasound, comprising:
1) offsetting a first transducer of the plurality of transducers for a position, phase, and amplitude of each of the plurality of transducers other than the first transducer to produce an instance of iterative transducer offset data; and
2) determining a phase and an amplitude of a point within a model volume by combining instances of iterative transducer offset data.
2. The method as in claim 1 , wherein offsetting the first transducer for the phase and amplitude of each of the plurality of transducers other than the first transducer involves interpolation.
3. The method as in claim 2 , wherein the interpolation is a linear interpolation.
4. The method as in claim 2 , wherein the interpolation is selected from a group consisting of a polynomial interpolation and a trigonometric interpolation.
5. The method as in claim 4 , wherein the group consisting of a polynomial interpolation and a trigonometric interpolation is a cosine interpolation.
6. The method as in claim 2 , wherein the interpolation is a parametric speaker interpolation.
7. The method as in claim 6 , wherein the parametric speaker interpolation comprises encoding a sinusoid into a parametric speaker beam to remove distortion.
8. The method as in claim 1 , wherein the pressure pattern produces haptic feedback.
9. The method as in claim 1 , wherein audio noise is reduced at the pressure pattern.
10. The method as in claim 1 , further comprising:
varying the position of the pressure pattern.
11. A system comprising:
a set of transducers creating an interpolation between:
(1) a first target pressure pattern associated with a first phase and amplitude configuration; and
(2) a second target pressure pattern associated with a second phase and amplitude configuration.
12. The system as in claim 11 , wherein the interpolation is a linear interpolation.
13. The system as in claim 11 , wherein the interpolation is selected from a group consisting of a polynomial interpolation and a trigonometric interpolation.
14. The system as in claim 13 , wherein the group consisting of a polynomial interpolation and a trigonometric interpolation is a cosine interpolation.
15. The system as in claim 11 , wherein the interpolation is a parametric speaker interpolation.
16. The system as in claim 11 , further comprising a control unit.
17. The system as in claim 11 , further comprising a driving unit.
18. The system as in claim 17 , wherein the driving unit is arranged to drive the transducer to produce ultrasound.
19. The system as in claim 16 , further comprising a control unit arranged to send control signals to the driving unit.
20. The system as in claim 16 , wherein the control unit includes a memory.