Abstract: An ultrasonic sensor detects a liquid level. A substrate (707) has an acoustic array (705). An acoustic diversion array (710) can be between a substrate edge (713) and the acoustic array. A sensing region (701) can lay next to the acoustic array opposite the acoustic diversion array. A collimation groove (706) can be in the substrate along a length of the acoustic array next to the liquid level sensing region. Multiple longitudinal folds (801, 802, 803) can run parallel to and between acoustic source and receive arrays. A feed strip (1201, 1202, 1309, 1311) can be used with a bend (1203, 1204) acoustically coupled to the acoustic array and an ultrasonic transducer at another end of the feed strip. The feed strip runs along the entire acoustic array when top fed and runs along part of the acoustic array when fed through a side of a tank (1401).

Abstract: An ultrasonic sensor detects a level of a fluid. A first probe has a first transducer element to transmit an ultrasonic signal through the first probe. A second probe of a helix shape has a second transducer element coiled around the first probe to receive the ultrasonic signal transmitted by the first probe through the fluid. A stabilizing rod and a plurality of stabilizing collets are disposed between the rod and the second probe parallel to both the first probe and the second probe.

Abstract: A touch panel as thin or thick as desired has increased touch sensitivity and decreased sensitivity to water includes. The panel or sensor includes a substrate having first and second surfaces and an edge between the surfaces defining a thickness. First and second pluralities of echelons are arranged on the substrate in first and second arrays along first and second centerlines. Each echelon in the pluralities of echelons is formed at an angle relative to their centerlines. First and second shear transducers are mounted on the edge of the substrate and are configured to generate shear waves in a source wave mode in a direction along their centerlines. The shear waves are reflected at the angle by the one or more of the plurality of echelons in the arrays to a sensing wave or the shear wave is converted to a different wave mode than the source mode. The sensing waves are reflected off of an edge opposing the centerlines and are sensed by the transducers.

Abstract: A touch panel has a substrate having first and second surfaces, and defines a touch surface. A first portion of a touch system includes a first plurality of echelons on the first surface in a first array along a first centerline. Each echelon is formed at an angle to the first centerline, and a first shear transducer assembly on the edge of the substrate that generates a shear wave in a source wave mode in a first direction along the first centerline. A second portion of the touch system includes a second plurality of echelons on the first surface in a second array along a second centerline, each echelon at a second angle to the second centerline. The second centerline is orthogonal to the first. A second shear transducer assembly is mounted on the edge and generates a shear wave in a source wave mode in a second direction along the second centerline. The first sensing mode is different from the second sensing mode.

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 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.