Abstract: An acoustic wave sensor/resonator utilizes a torsional wave trapped in an acoustic wave cavity that is formed in a noncylindrical substrate. An acoustic wave transducer is positioned adjacent the acoustic wave cavity off of the centerline of the cavity and in a plane parallel to a planar surface of the acoustic wave cavity to generate the torsional wave. The acoustic wave transducer can be a piezoelectric transducer or an electromagnetic transducer. Further, the torsional wave can be generated by a single transducer or multiple transducers.

Abstract: An acoustic wave sensor utilizes one or more acoustic waves trapped in an acoustic wave cavity to detect the presence of one or more substances on a surface of the acoustic wave cavity. To detect the presence of ice, a trapped torsional acoustic wave is used. To detect water, an acoustic wave with flexural or compressional components is used. The sensor includes a number of transducers adjacent the acoustic wave cavity where a controller drives different sets of the transducers to generate different acoustic waves.

Abstract: An acoustic wave sensor includes an electromagnetic acoustic transducer to generate a resonant acoustic wave substantially trapped in an acoustic wave cavity. The acoustic wave cavity is defined by a radially symmetric raised surface. The electromagnetic acoustic transducer includes a spiral primary coil to generate the acoustic wave in the acoustic wave cavity and a concentric spiral pickup coil to pick up an electrical signal representing the acoustic wave in the cavity. A noise canceling coil portion is used to cancel spurious noise induced by the primary coil from the pickup coil to provide an output signal representing the acoustic wave energy in the cavity 12.

Abstract: A circuit for an acoustic wave switch or sensor having a resonant acoustic wave cavity detects a touch or sensed event using a time domain approach. The circuit includes a controller that drives an acoustic wave transducer to generate a resonant acoustic wave in the acoustic wave cavity during a first portion of a sampling cycle. In a second portion of the sampling cycle, the controller monitors the time that it takes for the acoustic wave signal from the transducer to decay to a predetermined level. Based on the decay time, the controller detects a sensed event, such as a touch on the acoustic wave switch/sensor.

Abstract: An individual acoustic wave switch includes a body with a top section having an acoustic wave cavity formed therein and a base section extending downwardly from the top section. An acoustic wave transducer is mounted adjacent to a surface of the acoustic wave cavity opposite the touch surface thereof so as to generate an acoustic wave in the acoustic wave cavity and to pick up a signal representing the acoustic wave energy in the cavity. The acoustic wave switch is readily mounted in an aperture of a substrate through which the base of the switch extends.

Abstract: An acoustic wave sensor includes an electromagnetic acoustic transducer to generate a resonant acoustic wave substantially trapped in an acoustic wave cavity. The acoustic wave cavity is defined by a radially symmetric raised surface. The electromagnetic acoustic transducer includes a spiral primary coil to generate the acoustic wave in the acoustic wave cavity and a concentric spiral pickup coil to pick up an electrical signal representing the acoustic wave in the cavity. A noise canceling coil portion is used to cancel spurious noise induced by the primary coil from the pickup coil to provide an output signal representing the acoustic wave energy in the cavity 12.

Abstract: An acoustic wave switch includes a substrate with an acoustic wave cavity formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface of the acoustic wave cavity absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer. Various feedback mechanisms can be employed to provide a user with a tactile, audible and/or visual response indicating actuation of the switch by a touch.

Abstract: An acoustic wave switch includes a substrate with an acoustic wave cavity formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface of the acoustic wave cavity absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer. The acoustic wave switch has a high Q so as to enable a touch to be detected by extremely simple, low-cost circuitry. The acoustic wave switch of the present invention is rugged, explosion proof, operates in the presence of liquids and other contaminants, has a low power consumption and can be incorporated and integrally formed in a wall of a housing for a device.

Abstract: An acoustic wave switch includes a substrate with an acoustic wave cavity formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface of the acoustic wave cavity absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer. The acoustic wave switch has a high Q so as to enable a touch to be detected by extremely simple, low-cost circuitry. The acoustic wave switch of the present invention is rugged, explosion proof, operates in the presence of liquids and other contaminants, has a low power consumption and can be incorporated and integrally formed in a wall of a housing for a device.

Abstract: The present invention is directed to a touch screen sensor 10 that reduces or eliminates echoes or reflections of ultrasonic waves generated by one or more transducers 12. The touch screen sensor 10 is comprised of a wave absorption material 16 positioned around at least a portion of the perimeter 35 of the touch screen sensor 10.

Abstract: The present invention is directed to a touch panel for use in a touch position sensor. The touch panel includes a substrate fabricated at least partially from plastic materials. The plastic may be a polystyrene and/or copolymers of polystyrene. The touch panel utilizes transverse acoustic waves having a frequency in the range of 0.2 to 2.0 Megahertz to detect a touch on the touch panel.

Abstract: An acoustic wave touch panel comprising a substrate formed of a first material. The substrate is capable of supporting an acoustic wave for propagation therein. A reflective array upon the substrate is provided for reflecting an acoustic wave to propagate in the substrate. The reflective array is formed in the substrate. An inlay is formed of a second material. The inlay is disposed in the reflective array, wherein the acoustic wave has a velocity of propagation in the second material that is slower than the velocity of propagation of the acoustic wave in the first material.

Abstract: An acoustic touch position sensor is shown in which a number of transducers coupled to a side of a substrate impart a shear wave into the substrate for propagation along a number of paths parallel to a first axis. A reflective edge of the substrate first axis disposed along the first axis reflects the shear waves back along the parallel paths to the transducers. The transducers are responsive to the receipt of a shear wave for generating a signal representative thereof. A touch on the substrate results in perturbation in the shear wave which is sensed to determine the axial position of the touch on the substrate.

Abstract: An acoustic wave touch panel is shown for use with a non-active stylus. The acoustic wave touch panel includes an acoustic wave touch position sensor with an elastomeric substrate 20 overlying the touch position sensor and further including a stiff substrate overlying the elastomeric substrate. When a non-active stylus contacts a surface of the stiff substrate exerting a Z-axis force thereon, the Z-axis force is transmitted through the stiff substrate to the elastomeric substrate. The elastomeric substrate deforms in response to the Z-axis force and transmits the force to the acoustic wave touch sensor, the deformation of the elastomeric substrate absorbing or damping acoustic wave energy like a finger touch on the acoustic wave touch sensor.

Abstract: A controller for an acoustic wave touch panel includes a signal conditioning circuit that can generate X-axis and Y-axis burst drive signals for a touch panel as well as receive and process X-axis and Y-axis sense signals from a touch panel that can be configured with either one or two transducers per sense axis. The signal conditioning circuit includes a differential amplifier to which simultaneously received X-axis and Y-axis sense signals are applied to provide common mode rejection. The signal conditioning circuit includes a resonant circuit, in each of the X and Y channels, that forms a series resonant circuit through which a burst signal is applied to generate the transducer drive signal. The resonant circuit further forms a parallel resonant circuit of high impedance.

Abstract: An acoustic touch position sensor is shown in which a transducer coupled to a side of a substrate imparts a shear wave into the substrate for propagation along a first axis. A reflective array disposed along the first axis reflects portions of the shear wave along a plurality of parallel paths extending across a touch surface of the substrate to a second reflective array the axis of which is parallel to the first axis. The second reflective array reflects the shear waves incident thereto a receiving transducer mounted on the side of the substrate. A touch on the substrate results in perturbation in the shear wave which is sensed to determine the axial position of the touch on the substrate. A laminated touch panel is provided such that a back plate of any desired thickness is bounded onto the substrate. A non-shear wave coupling adhesive may be used to bond the back plate to the substrate.

Abstract: An acoustic touch position sensor is shown in which a transducer coupled to a side of a substrate imparts a shear wave into the substrate for propagation along a first axis. A reflective array is disposed along the first axis to reflect portions of the shear wave along a plurality of parallel paths extending across a touch surface of the substrate to a second reflective array the axis of which is parallel to the axis of the first reflective array. The second reflective array reflects the shear waves incident thereto to a transducer mounted on the side of the substrate and responsive to shear waves propagated thereto for providing a signal representative of these shear waves. A touch on the substrate results in a partial absorption of the energy in the shear wave so as to produce a perturbation therein which is sensed to determine the axial position of the touch on the substrate.

Abstract: An acoustic touch position sensor is shown in which a transducer coupled to a side of a substrate imparts a shear wave into the substrate for propagation along a first axis. A reflective array is disposed along the first axis to reflect portions of the shear wave along a plurality of parallel paths extending across a touch surface of the substrate to a second reflective array the axis of which is parallel to the axis of the first reflective array. The second reflective array reflects the shear waves incident thereto to a transducer mounted on the side of the substrate and responsive to shear waves propagated thereto for providing a signal representative of these shear waves. A touch on the substrate results in a partial absorption of the energy in the shear wave so as to produce a perturbation therein which is sensed to determine the axial position of the touch on the substrate.

Abstract: An acoustic touch position sensor is shown in which a transducer coupled to a side of a substrate imparts a shear wave into the substrate for propagation along a first axis. A reflective array is disposed along the first axis to reflect portions of the shear wave along a plurality of parallel paths extending across a touch surface of the substrate to a second reflective array the axis of which is parallel to the axis of the first reflective array. The second reflective array reflects the shear waves incident thereto to a transducer mounted on the side of the substrate and responsive to shear waves propagated thereto for providing a signal representative of these shear waves. A touch on the substrate results in a partial absorption of the energy in the shear wave so as to produce a perturbation therein which is sensed to determine the axial position of the touch on the substrate.

Abstract: An acoustic touch position sensor is shown wherein a Lamb wave is imparted into a substrate by a transducer mounted on the substrate, the Lamb wave propagating along a first axis. Top and bottom reflecting arrays are disposed along the first axis to reflect portions of one mode of the Lamb wave along a plurality of parallel paths extending across a touch surface of the substrate to a second pair of top and bottom reflect arrays. The second pair of top and bottom reflecting arrays reflect the Lamb waves incident thereto along an axis parallel to the first axis to a receiving transducer that provides a signal representative of the received Lamb waves. A touch on the substrate results in a partial absorption of the energy in the Lamb wave propagating along a path intersection the touch position so as to produce a perturbation therein which is sensed to determine the axial position of the touch on the substrate.