Capacitive pressure-sensing method and apparatus
AssigneeKey Concepts, Inc.
InventorsDonald A. Duncan, Jeffrey B. Tripp
Life of this patent
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Abstract
A novel capacitive pressure-sensitive sensing technique and apparatus wherein an elastomeric conductive electrode carrying a two-dimensional array of projections is pressure-deformed against a fixed coextensive cooperative electrode to generate signals, such as tones and sounds in the application to musical instruments, or visual representations, corresponding to the dynamic pressures applied over the two-dimensional surface. A novel drum-like and other musical instruments embodying such novel capacitive sensing techniques and the like are described.
Claims42
Apparatus comprising a capacitive pressure sensitive sensor having, in combination, first electrode means comprising a thin resilient conductive plastic sheet formed with a plurality of permanent, spaced, resiliently deformable, conductive projections protruding from one surface thereof and with adjacent regions pressure-deformable by application of pressure at an opposite surface thereof, and a second electrode means facing and coextensive with the projections and separated from the projections by a thin dielectric layer disposed between the projections and the second electrode means, with the first electrode means, the second electrode means, and the dielectric layer being disposed such that the projections may be resiliently deformed and compressed against the dielectric layer by the application of pressure at the opposite surface of said sheet, and with the projections being shaped such that the area thereof against the dielectric layer, and therefore the capacitance of said sensor, changes in a continuous manner with changes in compression of the projections against the dielectric layer due to changes in pressure at the opposite surface of said sheet.
A drum-like instrument having, in combination, a pressure-sensitive capacitive sensor including thin resilient conductive plastic electrode means formed with a plurality of permanent, spaced, resiliently deformable, conductive projections protruding from an inner surface thereof and with adjacent regions pressure-deformable by application of pressure at an outer surface thereof, a semi-rigid drum cover disposed over the outer surface of the resilient electrode means for receiving the pressure and conveying the same to the resilient electrode means, and a second electrode means facing and coextensive with the projections and separated from the projections by a thin dielectric layer disposed between the projections and the second electrode means, with the resilient electrode means, the second electrode means, and the dielectric layer being disposed such that the projections may be resiliently deformed and compressed against the dielectric layer by the pressure applied to the drum cover, and with the projections being shaped such that the area thereof against the dielectric layer, and therefore the capacitance of said sensor, changes in a continuous manner with changes in compression of the projections against the dielectric layer due to changes in pressure applied to the drum cover;
- and means connected with the first and second electrode means for applying ac voltage or current thereto and sensing changes in capacitance of the sensor with changes in the applied pressure.
A drum like instrument having, in combination, sensor means comprising thin resilient conductive elastomeric electrode means having adjacent regions pressure-deformable by application of pressure at the outer surface thereof and formed with a two-dimensional array of permanent, spaced, resiliently deformable projections protruding from an inner surface thereof, a semi-rigid drum cover disposed over the said outer surface for receiving the pressure and conveying the same to the resilient electrode means, and second electrode means facing and coextensive with the resilient electrode means and separated therefrom by a dielectric layer disposed between the resilient electrode means and the second electrode means such that the two said electrode means cannot come into contact with each other, with the resilient electrode means, the second electrode means, and the dielectric layer being disposed such that the projections may be resiliently deformed and compressed against the dielectric layer by the pressure applied to the drum cover, and with the projections being shaped such that the area thereof against the dielectric layer, and therefore the impedence of said sensor means, changes in a continuous manner with changes in compression of the projections against the dielectric layer due to changes in pressure applied to the drum cover;
- means connected with the two said electrode means for applying voltage or current thereto and sensing the changes in impedance of said sensor means;
- and means for producing signals corresponding to the sensed changes in impedance and generating sounds in response to said signals corresponding to the pressure applied to said drum cover.
A method of capacitive pressure-sensing, that comprises, subjecting adjacent regions of a permanently formed two-dimensional array of spaced, conductive, resiliently deformable plastic projections of tapered thickness to a contour of pressure dynamically applied in a predetermined direction and corresponding to a predetermined pressure pattern extending over one or more regions of the array, limiting movement of the projections in said predetermined direction at a fixed-position, coextensive, cooperative capacitive electrode surface separated from the array by a thin layer of dielectric material disposed between the array and the capacitive electrode surface so that the applied pressure dynamically deforms and compresses the thickness of the projections against the dielectric layer in such a manner that the area of the projections against the dielectric layer varies correspondingly, and sensing resulting dynamic capacitive variations effected by the projections to generate electrical signals corresponding to the capacitive variations.
Sensor apparatus comprising a pressure-sensitive capacitive sensor including first electrode means having a thin, pressure-deformable resilient conductive plastic sheet formed with a plurality of permanent, spaced, resiliently deformable conductive projections protruding from an inner surface thereof, second electrode means facing and coextensive with said projections, and a layer of dielectric material disposed between said projections and said second electrode means, said projections being depressible for resilient deformation indirectly against said second electrode means with said dielectric layer therebetween in contact with said projections by the application of deforming pressure to an outer surface of said plastic sheet, said projections further being shaped to compressively deform into contact with said dielectric layer over an increasing area with increasing deforming pressure on said outer surface of said plastic sheet such that said sensor exhibits capacitance corresponding to the deforming pressure.
Dependencies are inferred from the claim text.