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

• US 20050012724A1
• Filed: 04/20/2004
• Published: 01/20/2005
• Est. Priority Date: 04/19/1995
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Kent, Joel
• Granted Patent: US 7,061,475 B2
• Time in Patent Office: Days
• 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

1-69. -69. (canceled)

70. A touch position determination method, comprising:

receiving a plurality of signals representating a coordinate position of a touch on a surface, said plurality of signals comprising redundant information;

determining a consistency of the redundant information;

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

71. The method according to claim 70, wherein three representations are received for calculating a planar coordinate position.

72. The method according to claim 70, wherein redundant information is multiplexed onto a single datastream.

73. The method according to claim 70, wherein said plurality of representations comprise acoustic waveforms.

74. The method according to claim 70, wherein said plurality of representations each comprise a signal representing a physical axis, wherein the plurality of physical axes are non-orthogonal with respect to a coordinate output representation of a position of the touch.

75. The method according to claim 70, wherein said most likely position is determined based on a weighted average of the possible coordinates.

76. The method according to claim 70, wherein said most likely position is determined based on a set of representations most likely to provide reliable and accurate coordinate measurements.

77. The method according to claim 70, further comprising the step of classifying a characteristic of the touch.

78. The method according to claim 70, wherein a single signal comprises a plurality of representations.

79. The method according to claim 70, wherein a single signal comprises an ambiguity, wherein information from another signal is employed to resolve the ambiguity.

80. 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;

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.

81. The method according to claim 80, wherein said at least one wave comprises an acoustic wave.

82. The method according to claim 80, wherein the region is disposed in a substrate adapted for propagating acoustic waves.

83. The method according to claim 80, wherein said static structure comprises a pulse compression filter.

84. The method according to claim 80, wherein, prior to said receiving, the interacted wave energy is compressed in a manner inverse to said dispersing.

85. The method according to claim 80, 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.

86. The method according to claim 85, 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.

87. The method according to claim 80, wherein said transmitted 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.

88. The method according to claim 80, 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;

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