Abstract:
A thermally stable, mass-producible pointing device (10) producing an analog signal proportional to an applied force comprises actuator (20), including an arm (22) and a force transfer member (26), a connector (44), and a sensor (50). The connector maintains the force transfer member in contact with the sensor yet allows the force transfer member to change dimensions with ambient temperature without inducing stresses detectable by the sensor. In a preferred embodiment, the connector comprises an elastomeric adhesive and the sensor comprises a force-sensing resistor. The force transfer member is prevented from coming out of the assembly either by a retainer (12) comprising a shell or a potting compound retaining the force transfer member but permitting thermal expansion or contraction of the force transfer member. The force transfer member typically has a rounded or bevelled bottom surface (28) so the actuator rocks under an applied force. The area of the bottom surface of the force transfer member transferring the force changes as the actuator rocks, and the force is transferred to the sensor at a single contiguous area whose position changes in response to a change in force.
Abstract:
Production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-type non-conductive polymer containing carbon-nitrogen linkages, e.g., polyaniline, with a cation donor compound, such as R.sub.2 SO.sub.4, R'SO.sub.2 Cl or R".sub.3 SiCl, where R, R' and R" are alkyl or aryl, such as dimethyl sulfate or tosyl chloride, and forming an electrically conductive polymer in which the R groups of R.sub.2 SO.sub.4, the R'SO.sub.2 groups of R'SO.sub.2 Cl, or the R".sub.3 Si groups of R".sub.3 SiCl are covalently linked to the nitrogen atoms of the polymer.
Abstract:
A multipurpose keyboard incorporating an electronic pressure sensing device, a digitizer pad featuring spatial minimization of a pressure contact area capable of locating the leading and trailing edges of the pressure contact area is described. A processor coupled to the electronic pressure sensing device is programmed to sense when various regions on a simple, fully interchangeable template overlay and the underlying electronic pressure sensing device are depressed. The sensed region is associated by the processor with a particular key identification on the template overlay. The variation of the resistance in the digitizer pad enables the processor to detect the actuation of more than one key on the template overlay at the same time, thereby defecting key rollover. A method of fabrication for a multipurpose keyboard is also described.
Abstract:
A digitizer pad apparatus includes at least one digitizer ply where each digitizer ply has a first and a second resistor strip, each with a resistance gradient along its length, oriented in spaced apart relationship. A plurality of conductor traces are interconnected along the length of each resistor strip to extend toward and be interleaved between each other to define a sensor pad region. Each sensor pad region defines a dimensional direction. A shunt ply is positioned to face the sensor pad region in normally non-conducting relationship so that when a selected area is pressed into contact with the conductor traces, conduction between adjacent conductor traces via the shunt ply will occur in the selected contact area. The selected contact area has a first edge and a second edge opposite the first edge along the defined dimensional direction. A voltage source is coupled across the first resistor strip and a switch is coupled across the ends of the second resistor strip for alternately coupling one end and then the other end of the second resistor strip to a utilization. The voltage and hence the location of the first edge and then the second edge of the contact area along the dimensional direction is thereby determined.
Abstract:
A thermally stable, mass-producible pointing device (10) producing an analog signal proportional to an applied force comprises actuator (20), including an arm (22) and a force transfer member (26), a connector (44), and a sensor (50). The connector maintains the force transfer member in contact with the sensor yet allows the force transfer member to change dimensions with ambient temperature without inducing stresses detectable by the sensor. In a preferred embodiment, the connector comprises an elastomeric adhesive and the sensor comprises a force-sensing resistor. The force transfer member is prevented from coming out of the assembly either by a retainer (12) comprising a shell or a potting compound retaining the force transfer member but permitting thermal expansion or contraction of the force transfer member. The force transfer member typically has a rounded or bevelled bottom surface (28) so the actuator rocks under an applied force. The area of the bottom surface of the force transfer member transferring the force changes as the actuator rocks, and the force is transferred to the sensor at a single contiguous area whose position changes in response to a change in force.
Abstract:
Production of base-type conductive polymers, particularly from the family of conductive polyaniline, by reacting a base-type non-conductive polymer containing carbon-nitrogen linkages, e.g., polyaniline, with an anhydride, such as R--SO.sub.2 --O--SO.sub.2 --R', R--CO--O--CO--R', or R--CO--O--SO.sub.2 R', or mixtures thereof, where R and R' are alkyl or aryl, e.g., tosylic anhydride or benzophenone tetracarboxylic dianhydride, and forming an electrically conductive polymer in which the SO.sub.2 R and COR groups are covalently linked to the nitrogen atoms of the conductive polymer and the anion of the conductive polymer is the SO.sub.3 R' or O.sub.2 CR' group.
Abstract:
A process for fabricating an electronic device on a non-conductive polymer substrate, particularly from the family of polyaniline, comprises applying a covalent doping agent, such as an R.sup.+ donor compound, where R is an organic group, e.g., methyl iodide, to a preselected portion of a base-type non-conductive polymer substrate containing carbon-nitrogen linkages, and converting such preselected portion of the polymer substrate to an electrically conductive polymer portion, by covalent linkage of the R groups of such donor compound, to nitrogen atoms of the non-conductive polymer substrate. Electronic devices, such as resistors, capacitors, inductors, printed circuits and the like, can be provided by the invention process, in the form of light-weight polymers containing no metal, and which are stable and wherein the conductive portions are non-diffusing.
Abstract:
A variable resistance transducer responsive to an applied pressure including a smooth resistive layer on a flexible substrate and deposited thereon by printing or imaging technology, small points of nonconductive or semiconductive material, and resistive interdigitating fingers where in one finger is a wiper so that position on the resistive layer can be sensed.
Abstract:
A two-axis tilt sensor, or inclinometer (10), uses a spherical reference element (18) floating in an inert fluid (20) and including a magnet (42) to produce an asymmetrical weight distribution. The asymmetrical weight distribution maintains the spherical reference element at a constant orientation with respect to gravity, while the position of the magnet on the spherical reference element with respect to a housing (12) is detected by opposing pairs of Hall effect sensors (22) mounted on the housing. The outputs from opposing pairs of sensors are processed by differential amplifier circuits (80) to determine signals corresponding to the tilt of the inclinometer about the axes.
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.