Method and apparatus for producing an acoustic field
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:
a) producing an acoustic field in air using a plurality of ultrasonic transducers having known relative positions and orientations to each other;
b) tracking an object within the acoustic field;
c) using at least one point of focused ultrasound produced from at least two of the plurality of ultrasonic transducers, defining a virtual shape that occupies a virtual volume within the acoustic field, wherein the virtual shape is 3-dimensional; and
d) positioning one of the at least one point of focused ultrasound in a region where the object intersects the virtual shape.
2. The method of claim 1 , wherein positioning one of the at least one point of focused ultrasound occurs on an edge of the virtual shape.
3. The method of claim 1 , wherein positioning one of the at least one point of focused ultrasound occurs within the virtual shape.
4. The method of claim 1 , further comprising repositioning one of the at least one point of focused ultrasound in response to movement of the object.
5. The method of claim 4 , wherein the object is a human hand.
6. The method of claim 1 , further comprising modulating acoustic waves within the acoustic field at a frequency between 0.1 Hz to 500 Hz.
7. The method of claim 1 , further comprising modulating acoustic waves within the acoustic field at a frequency between 0 Hz and half of a carrier frequency of the acoustic waves.
8. A method comprising:
a) producing an acoustic field in air using a plurality of ultrasonic transducers having known relative positions and orientations to each other;
b) tracking an object within the acoustic field;
c) using at least two points of focused ultrasound produced from at least two of the plurality of ultrasonic transducers, defining a virtual shape that occupies a virtual volume within the acoustic field; and
d) positioning two of the at least two points of focused ultrasound in a region where the object intersects the virtual shape.
9. The method of claim 8 , wherein positioning two of the at least two points of focused ultrasound occurs on an edge of the virtual shape.
10. The method of claim 8 , wherein positioning two of the at least two points of focused ultrasound occurs within the virtual shape.
11. The method of claim 8 , further comprising repositioning two of the at least two points of focused ultrasound in response to movement of the object.
12. The method of claim 11 , wherein the object is a human hand.
13. The method of claim 8 , further comprising modulating acoustic waves within the acoustic field at a frequency between 0.1 Hz to 500 Hz.
14. The method of claim 8 , further comprising modulating acoustic waves within the acoustic field at a frequency between 0 Hz and half of a carrier frequency of the acoustic waves.
15. The method of claim 8 , wherein the virtual shape is 3-dimensional.
16. A system comprising:
an acoustic field in air produced using a plurality of ultrasonic transducers having known relative positions and orientations to each other;
a tracker of an object within the acoustic field;
a virtual shape defined using at least one point of focused ultrasound produced from at least two of the plurality of ultrasonic transducers that occupies a virtual volume within the acoustic field, wherein the virtual shape is 3-dimensional; and
one of the at least one point of focused ultrasound positioned in a region where the object intersects the virtual shape.
17. The system of claim 16 , wherein one of the at least one point of focused ultrasound is positioned on an edge of the virtual shape.
18. The system of claim 16 , wherein one of the at least one point of focused ultrasound is positioned within the virtual shape.
19. The system of claim 16 , further comprising one of the at least one point of focused ultrasound repositioned in response to a movement of the object.
20. The system of claim 19 , wherein the object is a human hand.
21. The system of claim 16 , further comprising acoustic waves within the acoustic field modulated at a frequency between 0.1 Hz to 500 Hz.
22. The system of claim 16 , further comprising acoustic waves within the acoustic field modulated at a frequency between 0 Hz and half of a carrier frequency of the acoustic waves.
23. A system comprising:
an acoustic field in air produced using a plurality of ultrasonic transducers having known relative positions and orientations to each other;
a tracker of an object within the acoustic field;
a virtual shape defined using at least two points of focused ultrasound produced from at least two of the plurality of ultrasonic transducers that occupies a virtual volume within the acoustic field;
wherein two of the at least two points of focused ultrasound are positioned in a region where the object intersects the virtual shape.
24. The system of claim 23 , wherein two of the at least two points of focused ultrasound are positioned on an edge of the virtual shape.
25. The system of claim 23 , wherein two of the at least two points of focused ultrasound are positioned within the virtual shape.
26. The system of claim 23 , further comprising two of the at least two points of focused ultrasound repositioned in response to movement of the object.
27. The system of claim 26 , wherein the object is a human hand.
28. The system of claim 23 , further comprising acoustic waves within the acoustic field modulated at a frequency between 0.1 Hz to 500 Hz.
29. The system of claim 23 , further comprising acoustic waves within the acoustic field modulated at a frequency between 0 Hz and half of a carrier frequency of the acoustic waves.
30. The system of claim 23 , wherein the virtual shape is 3-dimensional.