Abstract: The cost and complexity of an electronic pressure sensitive transducer are decreased by constructing such a transducer directly on a printed circuit board containing support electronics. Conductive traces are formed on the printed circuit board to define a contact area. A flexible substrate having an inner surface is positioned over the contact area. An adhesive spacer, substantially surrounding the contact area, attaches the flexible substrate to the printed circuit board. At least one resistive layer is deposited on the flexible substrate inner surface. In use, the resistive layer contacts at least two conductive traces in response to pressure applied to the flexible substrate to produce an electrical signal indicative of applied pressure.

Abstract: The cost and complexity of an electronic pressure sensitive transducer are decreased by constructing such a transducer directly on a printed circuit board containing support electronics. Conductive traces are formed on the printed circuit board to define a contact area. A flexible substrate having an inner surface is positioned over the contact area. An adhesive spacer, substantially surrounding the contact area, attaches the flexible substrate to the printed circuit board. At least one resistive layer is deposited on the flexible substrate inner surface. In use, the resistive layer contacts at least two conductive traces in response to pressure applied to the flexible substrate to produce an electrical signal indicative of applied pressure.

Abstract: A pressure transducer includes a base ply, a resistance ply disposed on the base ply and at least two spaced apart conductors juxtaposed in relation to the resistance ply whereby at least one of the conductors may be pressed against the resistance ply. The resistance ply is made by spraying or silk screening a mixture of a continuous matrix conductive resin and a stannous oxide particulate and then curing the composition to form a solid resistance ply having a surface with a multiplicity of micro-protrusions formed by the stannous oxide particulate.

Abstract: A digitizer pad includes at least two sets of terminals where each set has at least a first and second terminal positioned to define a parameter dimension therebetween. A resistor ply is disposed between the terminals of each set. The resistor ply has an electrical contact surface with a resistance gradient profile between the terminals in each set. An output terminal is electrically interconnected to a selected location along the contact surface of the resistor ply. A voltage source is sequentially coupled, by suitable switching means, across a selected subset of terminals in each set of terminals whereby the voltage at the output terminal is a measure of the selected location along the parameter dimension defined by the terminals across which the voltage source is coupled.

Abstract: A force sensing resistor (FSR) includes a substrate having separated electrically conductive traces and another substrate having a resistive layer in which the substrates are subjected to a biasing force such that the substrates contact one another with the resistive layer electrically connecting the traces with a resistance inversely dependent on the biasing force. Upon an external force applied towards a substrate, the substrates contact one another with a total force which is the sum of the forces with the resistive layer electrically connecting the traces with a resistance inversely dependent on the total force. An FSR output which is a function of the resistance is measured. Whether a change in magnitude of the FSR output during a time interval is greater than a threshold is determined. A touch applied on the FSR is detected during the time interval if the change is greater than the threshold.

Abstract: A pressure transducer includes a base ply, a resistance ply disposed on the base ply and at least two spaced apart contacts juxtaposed in relation to the resistance ply whereby at least one of the contacts may be pressed against the surface of the resistance ply. The resistance ply is made by spraying or silk screening a mixture of resin resistive to electrical conduction and a conductive particulate and then curing the composition to form a thin resistance ply having a surface with a multiplicity of micro-protrusions formed by the conductive particulate. The ratio of conductive particulate to resin is such that the mean distance between microprotrusions is greater than about five time the size of the conductive particles. The particles are in the range of about 0.5 to 10 microns and the resin layer is about is 0.4 to 0.8 microns thick.

Abstract: A force sensing resistor (FSR) includes a substrate having separated electrically conductive traces and another substrate having a resistive layer in which the substrates are subjected to a biasing force such that the substrates contact one another with the resistive layer electrically connecting the traces with a resistance inversely dependent on the biasing force. Upon an external force applied towards a substrate, the substrates contact one another with a total force which is the sum of the forces with the resistive layer electrically connecting the traces with a resistance inversely dependent on the total force. An FSR output which is a function of the resistance is measured. Whether a change in magnitude of the FSR output during a time interval is greater than a threshold is determined. A touch applied on the FSR is detected during the time interval if the change is greater than the threshold.

Abstract: A digitizer pad includes at least two base plys, each having thereon at least three terminals, a resistor ply disposed between two of the terminals with a plurality of conductors extending from each resistor ply which are spaced apart and interleaved with a plurality of conductors extending from each third terminal. The respective base plys' conducting surfaces face each other and are sandwiched about a nonconductive ply that includes a pressure sensitive conductive layer on each side, the area of which layer covers a portion of the area encompassed by the interleaved conductors on each base ply. The resistor plys and conductors on each base ply are at predetermined angles to those on the base ply, hence the conductors of each base ply form two predefined axes. A voltage source is sequentially coupled, by suitable switching means, across a selected pair of terminals on each ply to measure the selected location along the parameter dimension defined by the terminals across which the voltage source is coupled.