HAPTIC DEVICES
A haptic device that creates mechanical energy fields that can be felt but not heard. The haptic device provides annular array transducers that may be substantially transparent to visual light so they can be coupled with a wavefront display to allow a person to feel visual objects projected through it as holograms. A transparent array of annular array transducers may be controlled to provide steerable beams of mechanical energy fields to points in space using principles of interference and superposition.
1 . An annular transducer array comprising:
a plurality of concentric transducer rings located in a surface, centered on a point, having an outermost, and an innermost transducer ring;
wherein the outermost and innermost transducer rings are each driven by circuitry operable to cooperatively provide a mechanical energy field toward a volume in space.
2 . The annular transducer array of claim 1 , wherein the transducer rings are substantially transparent to electromagnetic energy comprising a modulated wavefront.
3 . The annular transducer array of claim 2 , wherein the modulated wavefront is modulated light.
4 . The annular transducer array of claim 1 , wherein the modulated wavefront is a spatially modulated wavefront.
5 . The annular transducer array of claim 4 , wherein the modulated wavefront is provided by one of a spatial light modulator (SLM) or a wavefront modulator.
6 . The annular transducer array of claim 1 , wherein the mechanical energy field is directional.
7 . The annular transducer array of claim 1 , wherein the surface is coplanar.
8 . The annular transducer array of claim 1 , wherein the transducer is substantially transparent.
9 . The annular transducer array of claim 1 , wherein greater than 50% of incident modulated wavefront light passes through unattenuated.
10 . The annular transducer array of claim 1 , wherein each concentric transducer ring has a predetermined resonant frequency
11 . The annular transducer array of claim 10 , wherein the resonant frequency is the same in the innermost transducer ring and the outermost transducer ring.
12 . The annular transducer array of claim 10 , wherein the resonant frequencies are different in the innermost transducer rings and the outermost transducer rings.
13 . The annular transducer array of claim 1 , wherein the resonant frequency of the concentric transducer rings is greater than 20 KHz.
14 . The annular transducer array of claim 13 , wherein the concentric transducer rings are further modulated at a frequency between 100 Hz to 250 Hz.
15 . The annular transducer array of claim 1 , further comprising additional rigs between the outermost and innermost transducer rings that are also each driven by circuitry.
16 . The annular transducer array of claim 1 , wherein the volume in space is a volume having a diameter in the range 1 mm to 5 mm.
17 . The annular transducer array of claim 1 , wherein the transducer rings are annular in shape.
18 . The annular transducer array of claim 1 , wherein the transducer is a micromachined ultrasonic transducer.
19 . The annular transducer array of claim 18 , wherein the micromachined ultrasonic transducer is one of a capacitive micromachined ultrasonic transducer and a piezoelectric micromachined ultrasonic transducer.
20 . The annular transducer array of claim 1 , wherein each transducer ring generates a mechanical energy field independent of other transducer rings in the annular transducer array.
21 . The annular transducer array of claim 20 , wherein selective driving of transducer rings in the annular transducer array provides directional control of the mechanical energy field.
22 . The annular transducer array of claim 1 , wherein activation of a plurality of rings in the annular array provides focal control of the mechanical energy field.
23 . The annular transducer array of claim 1 , wherein control parameters for each transducer ring are selected from the group of changing the drive frequency, phase delay, timing, and wave structure.
24 . The annular transducer array of claim 23 , wherein the wave structure is selected from the group of Bessel, sine, square, or superposition of waves.
25 . The annular transducer array of claim 1 , wherein each transducer ring is operable to have a different output level that can contribute to increasing the mechanical energy field for one direction and reducing the mechanical energy field in another direction.
26 . The annular transducer array of claim 1 , wherein the spacing between each transducer ring and thickness of each transducer ring is selected to define a mechanical energy field output and a resonance frequency.
27 . The annular transducer array of claim 1 , wherein the transducer rings are driven with spatiotemporal modulation operable to raster the mechanical energy field focal point at a first point in space multiple times per second.
28 . The annular transducer array of claim 27 , wherein the transducer rings are driven with spatiotemporal modulation operable to raster the sound focal point at a second point in space multiple times per second.
29 . The annular transducer array of claim 1 , wherein the transducer rings are driven with amplitude modulation operable to focus a sound focal point at a first point in space.
30 . The annular transducer array of claim 1 , wherein the transducer rings are driven with amplitude modulation and spatiotemporal modulation.
31 . An annular transducer array comprising:
annular sidewalls having concentric rings centered on a point;
a bottom electrode attached to the annular sidewalls;
a plurality of patterned electrodes arranged in concentric rings,
a piezoelectric membrane between the bottom electrode and the plurality of patterned electrodes,
wherein the piezoelectric membrane is operable to resonate between respective concentric rings in cooperation with a drive signal respectively applied to each patterned electrode.
32 . A haptic device, comprising:
a substrate;
sidewalls extending from the substrate and defining a cavity;
a membrane coupled to the sidewall and positioned over the cavity; and
electrodes operable to apply a voltage across the membrane;
wherein the membrane is operable to be vibrated due to the voltage and to generate mechanical energy towards a focal point in space.
33 . The haptic device of claim 1 , wherein the electrodes form an annular array pattern on the membrane.
34 . An array of annular transducer arrays of claim 1 , the array having at least two annular transducer arrays.
35 . The array of annular transducer arrays of claim 34 , further comprising a controller operable to control the transducer rings to direct the mechanical energy field toward the volume in space.
36 . The array of annular transducer arrays of claim 1 , wherein the array is substantially transparent.