Acoustic condition sensor employing a plurality of mutually non-orthogonal waves

• US 5,854,450 A
• Filed: 08/12/1996
• Issued: 12/29/1998
• Est. Priority Date: 04/19/1995
• Status: Expired due to Term

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touchsystems Incorporated (Elo Touch Solutions, Inc.)
• Inventors: Kent, Joel
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US08/695,716
• Time in Patent Office: 869 Days
• Field of Search: 345/173, 345/177, 367/907, 178/18.01, 178/18.03, 178/18.04, 178/19.02
• US Class Current: 178/18.04
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate
• CPC Class Codes: H03K 2217/96011 with propagation, SAW or BAW
• CPC Class Codes: Y10S 367/907 Coordinate determination

Abstract

A touch sensor, having an acoustic wave transmissive medium having a surface and a touch sensitive portion of the surface, a transducer system for emitting acoustic energy into the medium, and a receiver system for receiving the acoustic energy from the substrate as at least two distinct sets of waves, a portion of each of which overlap temporally at the receiver system or overlap physically by propagating in the touch sensitive portion along axes which are substantially non-orthogonal, the receiver system determining a position or a waveform perturbing characteristic of a touch on the touch sensitive portion. The receiver may be an amplitude detector or be sensitive to a phase-amplitude characteristic of the received acoustic waves.

Claims

1. A touch sensor comprising:

an acoustic wave transmissive medium having a surface and a touch sensitive portion of said surface;

a transducer system for emitting acoustic energy into said medium; and

a receiver system for receiving the acoustic energy from the substrate as at least two distinct sets of waves, a portion of each of which overlap temporally at said receiver system or overlap physically by propagating in said touch sensitive portion along axes which are substantially non-orthogonal;

said receiver system being for determining a position or a waveform perturbing characteristic of a touch on said touch sensitive portion.

2. The touch sensor according to claim 1, wherein said at least two distinct sets of waves from said touch sensitive surface propagate along different sensing axes.

3. The touch sensor according to claim 1, wherein said at least two distinct sets of waves from said touch sensitive surface are of differing wave propagation modes.

4. The touch sensor according to claim 1, wherein said at least two distinct sets of waves differ in frequency.

5. The touch sensor according to claim 1, wherein said at least two distinct sets of waves are emitted by a common transducer.

6. The touch sensor according to claim 5, wherein said at least two distinct sets of waves are emitted simultaneously.

7. The touch sensor according to claim 1, wherein said transducer system comprises at least one array of transducing elements.

8. The touch sensor according to claim 1, wherein said receiver system comprises at least one array of transducing elements.

9. The touch sensor according to claim 1, wherein said transducer system comprises a single electroacoustic transducer.

10. The touch sensor according to claim 1, wherein said receiver system comprises a single electroacoustic transducer.

11. The touch sensor according to claim 1, wherein at least two distinct wave paths intersect at a non-perpendicular angle.

12. The touch sensor according to claim 1, further comprising a reflective array, situated along a path, said path not being a linear segment parallel to a coordinate axis of a substrate in a Cartesian space, a segment parallel to an axial axis or perpendicular to a radial axis of a substrate in a cylindrical space, nor parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

13. The touch sensor according to claim 1, wherein said at least two distinct wave paths share a common segment wherein substantially all of the wave energy of each wave path travel.

14. The touch sensor according to claim 1, wherein said at least two distinct wave paths do not share a common segment wherein substantially all of the wave energy of each wave path travel.

15. The touch sensor according to claim 1, further comprising a reflective array intersecting acoustic paths, having a two dimensional Fourier transform with at least one useful spacing vector component.

16. The touch sensor according to claim 1, further comprising at least two reflective arrays intersecting acoustic paths, each having a two dimensional Fourier transform with one useful spacing vector component.

17. The touch sensor according to claim 1, further comprising a superposed reflective array intersecting acoustic paths, having a two dimensional Fourier transform with at least two useful spacing vector components.

18. The touch sensor according to claim 1, wherein said transducer system comprises a superimposed array.

19. The touch sensor according to claim 18, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves scattered at differing angles.

20. The touch sensor according to claim 18, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves of differing frequencies.

21. The touch sensor according to claim 18, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves of differing propagation modes.

22. The touch sensor according to claim 1, wherein said receiver system comprises a superimposed array.

23. The touch sensor according to claim 22, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves scattered at differing angles.

24. The touch sensor according to claim 22, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves of differing frequencies.

25. The touch sensor according to claim 22, wherein said superimposed array has a two dimensional Fourier transform with at least two useful spacing vector components for waves of differing propagation modes.

26. The touch sensor according to claim 1, wherein said at least two distinct sets of waves intersect at angles between about 10 and 80 degrees.

27. The touch sensor according to claim 1, wherein said at least two distinct sets of waves include a Rayleigh wave and a horizontally polarized shear wave.

28. The touch sensor according to claim 1, wherein said at least two distinct sets of waves include a higher order horizontally polarized shear wave.

29. The touch sensor according to claim 1, further comprising a reflective boundary for reflecting sets of acoustic waves.

30. The touch sensor according to claim 1, wherein said at least two distinct sets of waves comprise at least three distinct sets of waves.

31. The touch sensor according to claim 1, wherein said at least two distinct sets of waves have differing axes of propagation, said receiver system comprising at least two transducers, each receiving a portion of said at least two waves.

32. The touch sensor according to claim 1, wherein said at least two distinct sets of waves have differing axes of propagation, said transducer system comprising at least two transducers, each emitting a portion of said at least two sets of waves.

33. The touch sensor according to claim 1, wherein said at least two distinct sets of waves propagate simultaneously in said touch sensitive region.

34. The touch sensor according to claim 1, wherein said at least two distinct sets of waves do not propagate simultaneously in said touch sensitive region.

35. The touch sensor according to claim 1, wherein said receiver system is sensitive to waveform information of said received signals.

36. The touch sensor according to claim 1, wherein said receiver system is phase sensitive to said received signals.

37. The touch sensor according to claim 1, wherein portions of said at least two distinct sets of waves share are incident on a single receiving transducer simultaneously.

38. The touch sensor according to claim 1, further comprising means for determining the characteristic of the touch based on a pattern of perturbation of the received signal corresponding to a superposed wave consisting of portions of each of said at least two distinct sets of waves.

39. The touch sensor according to claim 1, further comprising means for recognizing perturbations in components of said received signal derived from each of said at least two distinct sets of waves.

40. The touch sensor according to claim 1, wherein said surface is planar.

41. The touch sensor according to claim 1, wherein said surface is cylindrical.

42. The touch sensor according to claim 1, wherein said surface is a large solid angle spheric section.

43. The touch sensor according to claim 1, wherein said at least two distinct sets of waves travel over differing paths, said receiver system determining a position of a perturbing influence and producing an output including a coordinate position, at least one of said coordinates of said coordinate position being calculated based on a transform of signals representing at least one of said sets of waves.

44. A touch sensor comprising:

an acoustic wave transmission medium having a surface and a touch sensitive portion of said surface;

a transducer system for emitting acoustic energy into said substrate; and

a receiver system for receiving acoustic energy from said substrate, preserving at least a portion of the phase-amplitude pattern of the acoustic energy,

said receiver system analyzing said received acoustic energy to detect a phase-amplitude perturbation thereof.

45. The touch sensor according to claim 44, further comprising a filter for selectively analyzing received acoustic energy signals corresponding to acoustic energy traveling a predetermined path from said transducer system.

46. The touch sensor according to claim 44, wherein said receiver system analyzes a phase pattern of said acoustic energy from said substrate for determining a position or a characteristic of a touch on said touch sensitive portion.

47. A touch sensor comprising:

an acoustic wave transmissive medium having a surface, an edge, and a touch sensitive portion of said surface medial to said edge;

a transducer system for emitting acoustic energy onto said touch sensitive portion as waves traveling along a plurality of sets of paths, each set of paths sharing a mutually exclusive common constraint with respect others of said plurality of sets of paths;

a receiver system for receiving acoustic energy from said touch sensitive portion from said plurality of sets of paths,

said plurality of sets of paths having at least two components propagating along a path intersecting a respective position along said edge, differing in propagation angle with respect to said edge.

48. The touch sensor according to claim 47, further comprising means for determining a position or a waveform perturbing characteristic of a touch on said touch sensitive portion based on at least two of said plurality of sets of paths.

49. A touch sensor comprising:

an acoustic wave transmissive medium having a surface and a touch sensitive portion of said surface;

a transducer system for emitting acoustic energy into said medium; and

a receiver system for receiving the acoustic energy from the substrate as at least three distinct sets of waves which propagate in the touch sensitive portion, each set of waves sharing a mutually exclusive common constraint with respect others of said sets of waves;

said receiver determining a position or a waveform perturbing characteristic of a touch on said touch sensitive portion based on said at least three sets of waves.

50. A touch sensor comprising:

an acoustic wave transmissive medium having a surface and a touch sensitive portion of said surface;

a transducer system for emitting acoustic energy into said medium; and

a receiver system for receiving the acoustic energy from the substrate, for determining a perturbation of said acoustic energy due to a touch on said surface,

said touch sensor comprising a reflective array having a plurality of spaced elements for scattering portions of an incident acoustic wave as waves having a different propagation vector than said incident acoustic wave and passing other portions unscattered, said reflective array being provided as reflective array selected from the group consisting of;

(a) a reflective array associated with said medium situated along a path, said path not being a linear segment parallel to a coordinate axis of a substrate in a Cartesian space, a segment parallel to an axial axis or perpendicular to a radial axis of a substrate in a cylindrical space, nor parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere;

(b) a reflective array situated along a path substantially not corresponding to a desired coordinate axis of a touch position output signal;

(c) a reflective array situated along a path substantially non-parallel to an edge of said medium;

(d) a reflective array having a spacing of elements in said reflective array which differs, over at least one portion thereof, from an integral multiple of a wavelength of an incident acoustic wave;

(e) a reflective array having elements in said reflective array which are non-parallel;

(f) a reflective array having an angle of acceptance of acoustic waves which varies over regions of said reflective array;

(g) a reflective array which coherently scatters at least two distinguishable acoustic waves which are received by said receiving system; and

(h) combinations and subcombinations of the above, except that said reflective array in (d), (e) or

(f) is not provided parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

51. The touch sensor according to claim 50, wherein said array is associated with said medium being situated along a path, said path not being a linear segment parallel to a coordinate axis of a substrate in a Cartesian space, a segment parallel to an axial axis or perpendicular to a radial axis of a substrate in a Cylindrical space, and parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

52. The touch sensor according to claim 50, wherein said array is situated along a path substantially not corresponding to a desired coordinate axis of a touch position output signal.

53. The touch sensor according to claim 50, wherein said array is situated along a path substantially non-parallel to an edge of said medium.

54. The touch sensor according to claim 50, wherein said array has a spacing of elements in said array which differs, over at least one portion thereof, from an integral multiple of a wavelength of an incident acoustic wave, said array not being provided parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

55. The touch sensor according to claim 50, wherein said array has elements in said array which are non-parallel, said array not being provided parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

56. The touch sensor according to claim 50, wherein said array has an angle of acceptance of acoustic waves which varies over regions of said array, said array not being provided parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere.

57. The touch sensor according to claim 50, wherein said array coherently scatters at least two distinguishable acoustic waves which are received by said receiving system.