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

• US 7,061,475 B2
• Filed: 04/20/2004
• Issued: 06/13/2006
• Est. Priority Date: 04/19/1995
• Status: Expired due to Fees

• 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:
  US10/827,847
• Publication Number:
  US 20050012724A1
• Time in Patent Office: 784 Days
• Field of Search: 345173-180, 178 1801- 1807, 178 1901- 1905, 367/907
• US Class Current: 345/177
• 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 comprising an acoustic wave transmissive medium having a surface; a plurality of acoustic wave path forming systems, each generating a set of incrementally varying paths through said transmissive medium; and a receiver, receiving signals representing said sets of waves, a portion of each set overlapping temporally or physically by propagating in said transmissive medium along axes which are not orthogonal. The waves may also be of differing wave modes. The receiver system may include a phase, waveform or amplitude sensitive system. Reflective arrays are 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; situated along a path substantially not corresponding to a desired coordinate axis of a touch position output signal; situated along a path substantially non-parallel to an edge of said medium; 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; has elements in said array which are non-parallel; has an angle of acceptance of acoustic waves which varies over regions of said array; and/or coherently scatter at least two distinguishable acoustic waves which are received by said receiving system.

Claims

1. A system for determining a position, comprising:

a transducer for transmitting at least one wave;

a static structure for dispersing the at least one wave to provide wave energy over a region in which position is to be sensed;

a transducer for receiving the at least one wave from the region, representing wave energy which has interacted with an object within the region, while retaining wave path information; and

a processor for analyzing a perturbation of the interacted wave energy by the object and wave path information to determine a position of the object,

wherein the processor adapts the transmitted at least one wave based on a characteristic of the region determined based on the received interacted signal.

2. The system according to claim 1, wherein said at least one wave comprises an acoustic wave.

3. The system according to claim 1, further comprising a substrate on which the region is disposed, adapted for propagating acoustic waves.

4. The system according to claim 1, wherein said static structure comprises a pulse compression filter.

5. The system according to claim 1, further comprising a second static structure for compressing the at least one interacted wave an a manner inverse from the dispersing of said static structure.

6. The system according to claim 1, wherein said static structure for dispersing is a passive structure having at least one two dimensional Fourier transform with an admittance for a desired wave or set of waves.

7. The system according to claim 6, wherein said static structure for dispersing is a passive structure having at least two distinct two dimensional Fourier transforms, with admittance for at least two different sets of waves.

8. The system according to claim 1, wherein said dispersed wave comprises a plurality of waves characterized in that the plurality of waves have:

non-orthogonal axes of propagation, differing wave propagation mode, differing frequency, wavelength or phase velocity.

9. The system according to claim 1, said processor further:

receiving a plurality of interacted waves representing a coordinate position of an object in the region, said plurality of interacted waves comprising redundant information;

determining a consistency of the redundant information; and

outputting a most likely position of the object based on the plurality of representations.

10. A computer readable storage medium, having stored thereon instructions for causing a general purpose processor to perform the steps of:

transmitting at least one wave;

receiving the at least one wave, representing physically dispersed wave energy which has interacted with an object within a region, while retaining wave path information;

analyzing a perturbation of the interacted wave energy by the object and wave path information to determine a position of the object,

adapting the at least one transmitted wave to a characteristic of the region determined based on the received interacted signal.

11. The computer readable storage medium according to claim 10, wherein said processor is caused to perform the further steps of:

receiving a plurality of interacted waves representing a coordinate position of an object in the region, said plurality of interacted waves comprising redundant information;

determining a consistency of the redundant information; and

outputting a most likely position of the object based on the plurality of representations.

12. A method for determining a position, comprising:

transmitting at least one wave;

dispersing the at least one wave with a static structure to provide wave energy over a region in which position is to be sensed;

interacting the wave energy with an object within the region;

receiving the at least one wave from the region, representing the interacted wave energy, while retaining wave path information; and

analyzing a perturbation of the interacted wave energy by the object and wave path information to determine a position of the object,

wherein said transmitting is adaptive to a characteristic of the region determined based on the received interacted signal.

13. The method according to claim 12, wherein said at least one wave comprises an acoustic wave.

14. The method according to claim 12, wherein the region is disposed in a substrate adapted for propagating acoustic waves.

15. The method according to claim 12, wherein said static structure comprises a pulse compression filter.

16. The method according to claim 12, wherein, prior to said receiving, the interacted wave energy is compressed in a manner inverse to said dispersing.

17. The method according to claim 12, wherein said static structure for dispersing is a passive structure having at least one two dimensional Fourier transform with an admittance for a desired wave or set of waves.

18. The method according to claim 17, wherein said static structure for dispersing is a passive structure having at least two distinct two dimensional Fourier transforms, with admittance for at least two different sets of waves.

19. The method according to claim 12, wherein said dispersed wave comprises a plurality of waves characterized in that the plurality of waves have:

non-orthogonal axes of propagation, differing wave propagation mode, differing frequency, wavelength or phase velocity.

20. The method according to claim 12, further comprising the steps of:

receiving a plurality of interacted waves representing a coordinate position of an object in the region, said plurality of interacted waves comprising redundant information;

determining a consistency of the redundant information; and

outputting a most likely position of the object based on the plurality of representations.