Method and apparatus for providing tactile sensations
The present disclosure concerns a method and apparatus for the creation of an acoustic field for providing tactile sensations. More particularly, but not exclusively, this disclosure concerns a method and apparatus for the creation of an acoustic field providing tactile sensations for use with an interactive device. The disclosure provides a method of generating a tactile sensation. The method comprises the steps of providing a plurality of acoustic transducers arranged to generate a predetermined distribution of pressure patterns, wherein the pressure patterns comprise a first region providing a first tactile sensation and a second region providing a second, different, tactile sensation.
1. A method of generating a tactile sensation comprising the steps of:
providing a plurality of ultrasonic transducers arranged to generate a predetermined distribution of non-surface pressure patterns in mid-air using an ultrasonic carrier frequency modulated at a lower frequency so as to be detectable by human skin,
wherein the pressure patterns comprise a first non-surface region comprising a focal point for a plurality of acoustic waves modulated at a first frequency providing a first tactile mid-air sensation on human skin, and a second non-surface region comprising a focal point for a plurality of acoustic waves modulated at a second frequency providing a second tactile mid-air sensation on human skin;
wherein the first frequency is different than the second frequency;
wherein the first tactile mid-air sensation is different than the second tactile mid-air sensation;
wherein the pressure patterns are created using a modeling algorithm having three steps,
wherein the first step comprises calculating an acoustic field for a selected transducer within the plurality of ultrasound transducers;
wherein the second step comprises defining a plurality of control points in mid-air; and
wherein the third step comprises calculating optimal phases using a minimum norm solver.
2. The method as in claim 1 , wherein the first step further comprises calculating a phase and amplitude for a location in mid-air by calculating a sum of a position offsets, phase offsets, and amplitude offsets from the sample transducer for each of the plurality of ultrasound transducers other than the sample transducer.
3. The method as in claim 1 , wherein one of the plurality of control points is a point of maximum intensity.
4. The method as in claim 1 , wherein one of the plurality of control points is a null point.
5. The method as in claim 1 , wherein a first of the plurality of control points is defined with a first modulation frequency and a second of the plurality of control points is defined with a second modulation frequency.
6. The method as in claim 1 , wherein the third step further comprises calculating a plurality of iterative optimal phases to determine the highest intensity for the plurality of control points.
7. The method as in claim 1 , wherein the plurality of control points are assigned by a user.
8. The method as in claim 1 , wherein the plurality of control points are assigned by an automated process.
9. A system for providing tactile sensations comprising:
an interactive device;
a plurality of ultrasonic transducers arranged to generate a predetermined distribution of non-surface pressure patterns in mid-air using an ultrasonic carrier frequency modulated at a lower frequency so as to be detectable by human skin,
wherein the pressure patterns comprise a first non-surface region comprising a focal point for a plurality of acoustic waves modulated at a first frequency providing a first tactile mid-air sensation on human skin, and a second non-surface region comprising a focal point for a plurality of acoustic waves modulated at a second frequency providing a second tactile mid-air sensation on human skin;
wherein the first frequency is different than the second frequency; and
wherein the first tactile mid-air sensation is different than the second tactile mid-air sensation.
10. The system as in claim 9 wherein the interactive device has a display side and a non-display side and wherein the plurality of ultrasonic transducers are adjacent to the non-display side and the pressure patterns are created adjacent to the display side.
11. The system as in claim 10 wherein the interactive device displays visual information on the display side.
12. The system as in claim 10 wherein the visual information is correlated with the pressure patterns.
13. The system as in claim 12 further comprising a tracking device for detecting an object movement.
14. The system as in claim 13 wherein the interactive device displays visual information on the display side and wherein the visual information is correlated with the object movement detected by the tracking device.
15. The system as in claim 13 wherein the interactive device comprises a plurality of buttons.
16. The system as in claim 13 wherein the pressure patterns comprise a slider switch.
17. The system as in claim 9 wherein the interactive device is integrated into a neck rest of a car seat and wherein the pressure patterns provide tactile information on a neck of a user.
18. The system as in claim 9 , wherein the pressure patterns provide tactile information designated for a specific finger of a user.