590 results about "Capacitive transducer" patented technology

An apparatus comprises a fingerprint sensor having a set of capacitive elements configured for capacitively coupling to a user fingerprint. The fingerprint sensor may be disposed under a control button or display element of an electronic device, for example one or more of a control button and a display component. A responsive element is responsive to proximity of the user fingerprint, for example one or both of a first circuit responsive to motion of the control button, and a second circuit responsive to a coupling between the fingerprint and a surface of the display element. The fingerprint sensor is disposed closer to the fingerprint than the responsive element. The control button or display component may include an anisotropic dielectric material, for example sapphire.

A tactile touch-sensitive device for use as an electronic input device for navigating an electronic document on a display device is described. The tactile aspect of the device provides a document location indicator, such as a protrusion or a depression, which may be perceived through the sense of touch. The device may incorporate additional features such as multiple modes of navigation, namely isotonic and isometric scrolling. Various sensors, such as force sensors and capacitive sensors, may provide the user with coarse and fine scrolling capabilities through different types of interactions with the scrollbar. The force sensors may allow the user to alter the rate of scrolling by adjusting the magnitude of force applied. Additionally, capacitive sensors may detect absolute positions of a user's finger movement and navigate through a document pursuant to those movements.

The present invention is directed to a process for the manufacture of a plurality of integrated capacitive transducers. The process comprises the steps of supplying a first substrate of a semiconductor material having first and second faces, supplying a second substrate of a semiconductor material having first and second faces, forming a diaphragm layer on the first face of the first substrate, forming a backplate layer on the first face of the other of the second substrate, forming a support layer on the backplate layer, etching a plurality of supports from the support layer, for each of the capacitive transducers, etching a plurality of vents from the backplate layer, for each of the capacitive transducers, positioning the diaphragm layer of the first substrate adjacent with the support layer of the second substrate, and welding the diaphragm layer and the support layer together, removing at least a portion of the first substrate to expose the diaphragm layer, for each of the capacitive transducers, removing a portion of the second substrate to expose the vents, for each of the capacitive transducers, and, etching a portion of the diaphragm layer, for each of the capacitive transducers.

This invention describes the deficiencies of current art for sensitive impedance sensors, particularly capacitive sensors, and describes several circuits that improve measurement of small value capacitances, especially in the presence of noise. It also shows various circuit architectures optimized for different capacitive sensing tasks. The circuits also describe a novel method to linearize a conventional charge-transfer capacitive sense circuit and a novel method to eliminate the effect of stray capacitance in charge-transfer capacitive sensors.

A semiconductor die with an integrated electronic circuit, configured so as to be mounted in a housing with a capacitive transducer e.g. a microphone. A first circuit is configured to receive an input signal from the transducer at an input node and to provide an output signal at a pad of the semiconductor die. The integrated electronic circuit comprises an active switch device with a control input, coupled to a pad of the semiconductor die, to operatively engage or disengage a second circuit interconnected with the first circuit so as to operate the integrated electronic circuit in a mode selected by the control input. That is, a programmable or controllable transducer. The second circuit is interconnected with the first circuit so as to be separate from the input node. Thereby less noise is induced, a more precise control of the circuit is obtainable and more advanced control options are possible.

An apparatus comprising a capacitive transducer, for example a MEMS microphone. A first voltage generator is connected to receive a first voltage (VDD*) and generate a second voltage (VCP) for biasing the capacitive transducer. A control circuit is adapted to, in use, control the first voltage (VDD*) based on a calibration value, wherein a different calibration value would lead to a different first voltage level and the calibration value is set such that an input signal of known amplitude produces an output signal of predetermined amplitude.

A system for sensing environmental conditions on a window assembly. The system includes a transparent panel and a sensor integrated onto the panel. The sensor being configured to sense environmental changes on the panel. The sensor may comprise conductive inks that are printed onto the window assembly. The window assembly may comprise a plastic panel, such as a multilayer polycarbonate panel such that a portion of the sensor may be located on the one layer of the panel while another portion of the sensor overlaps the first portion on a second layer of the window. The sensor may be a resistive or capacitive sensor and may be configured to detect changes in one or more environmental conditions, such as temperature or moisture. Further, the sensor may be in electrical communication with a controller configured for control various vehicle subsystems based on the sensor.

A MEMS capacitive transducer with increased robustness and resilience to acoustic shock. The transducer structure includes a flexible membrane supported between a first volume and a second volume, and at least one variable vent structure in communication with at least one of the first and second volumes. The variable vent structure includes at least one moveable portion which is moveable in response to a pressure differential across the moveable portion so as to vary the size of a flow path through the vent structure. The variable vent may be formed through the membrane and the moveable portion may be a part of the membrane, defined by one or more channels, that is deflectable away from the surface of the membrane. The variable vent is preferably closed in the normal range of pressure differentials but opens at high pressure differentials to provide more rapid equalisation of the air volumes above and below the membrane.

The present invention provides a method for capacitive detection of the presence of target sample on a substrate, which comprises the steps of: binding a target sample to selective binding sites on the substrate, the target sample being directly or indirectly labeled with conductive labels, and sensing the presence of the bound conductive labels to a binding site to thereby determine the presence of the target sample. The sensing step is carried out by a capacitive detection of the presence of the conductive labels. The present invention also provides a capacitive sensor device for determining the presence of a target sample. Conductive labels are directly or indirectly couplable to the target sample. The capacitive sensor device comprises a substrate having attached thereto a binding site able to selectively bind a target sample, a capacitive sensor element, and sensing circuitry for determining the presence of a target sample bound to the binding site by application of electrical signals to a capacitive sensor element. The capacitive sensor element comprises a set of at least two electrodes with non-conductive surfaces in a region associated with the binding site.

A variable capacitor for sensing the level of a liquid. The capacitor provides a readable capacitance that varies with respect to the level of the liquid. A pump control system implementing the capacitive sensor to control the level of a liquid by activating and deactivating the pump depending on the level of the liquid. Methods relating to varying capacitance of a capacitive sensor and controlling a pump based on the level of a liquid. A pump controller for controlling the level of a liquid in a reservoir includes a controller and a capacitor. The capacitor is adapted to provide an activation signal to the controller when the liquid in the reservoir reaches a first predetermined level relative thereto. Additionally, the capacitor is adapted to provide a trigger signal to the controller when the liquid in the reservoir reaches a second predetermined level relative thereto. Based on the trigger signal, the controller determines when to deactivate the pump.

A unique conductivity pattern is applied to printable articles to provide a “signature” for later verifying the authenticity of the printable articles. Preferably, the conductivity pattern is hidden from sight and differs from other conductivity patterns applied to other printable articles in an effectively random manner. Capacitive sensors read the conductivity patterns, and the resulting data for recording the signatures reflects not only details of the conductivity patterns themselves but also the characteristics of the capacitive sensors and their use.

Systems, articles, and methods for improved capacitive electromyography (“EMG”) sensors are described. The improved capacitive EMG sensors include one or more sensor electrode(s) that is / are coated with a protective barrier formed of a material that has a relative permittivity ∈r of about 10 or more. The protective barrier shields the sensor electrode(s) from moisture, sweat, skin oils, etc. while advantageously contributing to a large capacitance between the sensor electrode(s) and the user's body. In this way, the improved capacitive EMG sensors provide enhanced robustness against variations in skin and / or environmental conditions. Such improved capacitive EMG sensors are particularly well-suited for use in wearable EMG devices that may be worn by a user for an extended period of time and / or under a variety of skin and / or environmental conditions. A wearable EMG device that provides a component of a human-electronics interface and incorporates such improved capacitive EMG sensors is described.

An anti-pinch assembly is used for a closure panel supported by the motor vehicle. The closure panel is movable between an open position and a closed position. A controller is operably connected to the closure panel for controlling the operation of the closure panel. A position sensor is connected to the controller for indicating the position of the closure panel as the closure panel moves between the open and closed positions. A capacitive sensor is mounted on the frame of the vehicle and connected to the controller for providing an output signal to the controller indicative of the presence of a foreign object in the path of the closure panel. The controller varies the function of the capacitive sensor through a plurality of threshold levels as a function of the position of the closure panel as indicated by the position indicator. In a critical zone of travel, namely, travel of the closure panel nearing the closed position, the capacitive sensor can be utilized in either a contact mode or a non-contact mode or a combination of both.

Systems, articles, and methods for surface electromyography (“EMG”) sensors that combine elements from traditional capacitive and resistive EMG sensors are described. For example, capacitive EMG sensors that are adapted to resistively couple to a user's skin are described. Resistive coupling between a sensor electrode and the user's skin is galvanically isolated from the sensor circuitry by a discrete component capacitor included downstream from the sensor electrode. The combination of a resistively coupled electrode and a discrete component capacitor provides the respective benefits of traditional resistive and capacitive (respectively) EMG sensor designs while mitigating respective drawbacks of each approach. A wearable EMG device that provides a component of a human-electronics interface and incorporates such capacitive EMG sensors is also described.

The devices presented herein are capacitive sensors with single crystal silicon on all key stress points. Isolating trenches are formed by trench and refill forming dielectrically isolated conductive silicon electrodes for drive, sense and guards. For pressure sensing devices according to the invention, the pressure port is opposed to the electrical wire bond pads for ease of packaging. Dual-axis accelerometers measuring in plane acceleration and out of plane acceleration are also described. A third axis in plane is easy to achieve by duplicating and rotating the accelerometer 90 degrees about its out of plane axis Creating resonant structures, angular rate sensors, bolometers, and many other structures are possible with this process technology. Key advantages are hermeticity, vertical vias, vertical and horizontal gap capability, single crystal materials, wafer level packaging, small size, high performance and low cost.

Capacitance measurement apparatus that enhances the sensitivity and accuracy of capacitive transducers, proximity sensors, and touchless switches. Each of two capacitors (C1, C2) under measurement has one end connected to ground and is kept at substantially the same voltage potential by operational amplifier (A1) or amplifiers (A0, A1) using negative feedback. The apparatus is driven by a periodic e.g. sinusoidal signal source (G1) or sources (G1, G2) and includes a difference amplifier (A2) operative to produce an electrical signal having a linear relationship with a specified arithmetic function of the capacitances of the two capacitors (C1, C2). A touchless switch is implemented using the capacitance measurement apparatus. The touchless switch includes two sensor electrodes (E1, E2) that correspond to the two capacitors (C1, C2) under measurement and in one embodiment has a front surface in the form of a container.

Micromechanical structures having at least one lateral capacitive transducer gap filled with a dielectric and method of making same are provided. VHF and UHF MEMS-based vibrating micromechanical resonators filled with new solid dielectric capacitive transducer gaps to replace previously used air gaps have been demonstrated at 160 MHz, with Q's˜20,200 on par with those of air-gap resonators, and motional resistances (Rx's) more than 8× smaller at similar frequencies and bias conditions. This degree of motional resistance reduction comes about via not only the higher dielectric constant provided by a solid-filled electrode-to-resonator gap, but also by the ability to achieve smaller solid gaps than air gaps. These advantages with the right dielectric material may now allow capacitively-transduced resonators to match to the 50-377Ω impedances expected by off-chip components (e.g., antennas) in many wireless applications without the need for high voltages.

A wireless charger with combined electric radiation shielding and capacitive sensing functions is provided. The wireless charger comprises a charging module, a capacitive sensor, and a control unit. The charging module comprises a first coil, a placing area, and a comb-shaped shielding located between the placing area and the first coil. The capacitive sensor is connected to the comb-shaped shielding to detect the capacitance varient between the comb-shaped shielding and the environment. When the wireless charger is in a standby mode, the comb-shaped shielding is for sensing capacitance. When the capacitance varient exceeds a predefined threshold and an electronic device for wireless charging is placed on the placing area, the control unit switches the wireless charger to a charging mode and the comb-shaped shielding is for electric radiation shielding.

Disclosed is an apparatus for induced capacitor, an insulating substrate; and a plurality of capacitive sensing devices, being arranged on the insulating substrate in a matrix form, each of the plurality of capacitive sensing devices further comprising: a first electrode; and a second electrode, having an inner rim and an outer rim, being disposed circumferentially surrounding the first electrode while separating the second electrode from first electrode by a distance so as to form an equivalent capacitance therebetween, wherein a potential of each capacitive sensing device formed between the two electrodes is adjusted to be a predetermined value by adjusting the distance between the inner rim of the second electrode and the circumference of the first electrode while keeping the outer rim of the second electrode fixed.

A MEMS capacitive transducer with increased robustness and resilience to acoustic shock. The transducer structure includes a flexible membrane supported between a first volume and a second volume, and at least one variable vent structure in communication with at least one of the first and second volumes. The variable vent structure includes at least one moveable portion which is moveable in response to a pressure differential across the moveable portion so as to vary the size of a flow path through the vent structure. The variable vent may be formed through the membrane and the moveable portion may be a part of the membrane, defined by one or more channels, that is deflectable away from the surface of the membrane. The variable vent is preferably closed in the normal range of pressure differentials but opens at high pressure differentials to provide more rapid equalization of the air volumes above and below the membrane.

A capacitive transducer circuit comprises a capacitive transducer having first and second electrodes. The first and second electrodes are biased by respective first and second bias voltages. An amplifier is connected to receive a first analogue signal on an input terminal, the first analogue signal being generated by the capacitive transducer, and to generate a second analogue signal on an output terminal. A digital feedback circuit is connected between the output terminal of the amplifier and the input terminal of the amplifier. The digital feedback circuit is configured to provide one of said first or second bias voltages. The output of a voltage source which provides the other bias voltage for the capacitive transducer may be filtered by a low pass filter. The low pass filter may comprise a switched capacitor filter circuit.

A capacitive sensor includes a conductive elastomer portion formed into a pre-determined shape to sense a touch of a user within a sensing zone of the conductive elastomer portion, a dielectric portion disposed adjacent the conductive elastomer portion within the sensing zone of the conductive elastomer portion, and a controller in electrical communication with the conductive elastomer portion to detect a change in an electrical characteristic of the conductive elastomer portion.

A capacitive sensor includes: a first sensing electrode connected to a first reference capacitor in which is stored reference electric charge; a second sensing electrode connected to a second reference capacitor in which is stored reference electric charge; and a shield electrode to which is applied electric potential equal to that of the first sensing electrode and the second sensing electrode. The first sensing electrode positions adjacent to a detecting surface of the capacitive sensor, and the second sensing electrode positions opposite to the detecting surface in such a manner that the first and second sensing electrodes are spaced apart and facing to each other. The shield electrode is configured to partly expose the first and second sensing electrodes on the side of the detecting surface, and the shield electrode extends toward the detecting surface beyond the first sensing electrode.

A method for enhancing the linearity of a differential capacitive sensor as a function of beam displacement. An ac-modulated feedback connection from a sensor output terminal to a movable beam electrode is provided through a fix-up capacitor. The output terminal signal is inverted in the feedback connection so that the fix-up capacitor reduces the capacitance from the fixed electrodes to the beam electrode. When the fix-up capacitor value is chosen approximately equal to the fixed capacitance of the differential capacitor, the feedback circuit compensates for the effect of this fixed capacitance. The linearity of the output as a function of the displacement of the beam is improved. Thus, the signal-to-noise ratio of devices such as accelerometers may be increased by allowing sensors to employ a large displacement range. The invention may be used in differential accelerometers and in other types of differential capacitive sensors.

Systems, articles, and methods for surface electromyography (“EMG”) sensors that combine elements from traditional capacitive and resistive EMG sensors are described. For example, capacitive EMG sensors that are adapted to resistively couple to a user's skin are described. Resistive coupling between a sensor electrode and the user's skin is galvanically isolated from the sensor circuitry by a discrete component capacitor included downstream from the sensor electrode. The combination of a resistively coupled electrode and a discrete component capacitor provides the respective benefits of traditional resistive and capacitive (respectively) EMG sensor designs while mitigating respective drawbacks of each approach. A wearable EMG device that provides a component of a human-electronics interface and incorporates such capacitive EMG sensors is also described.

Capacitance measurement apparatus that enhances the sensitivity and accuracy of capacitive transducers, proximity sensors, and touchless switches. Each of two capacitors (C1, C2) under measurement has one end connected to ground and is kept at substantially the same voltage potential by operational amplifier (A1) or amplifiers (A0, A1) using negative feedback. The apparatus is driven by a periodic e.g. sinusoidal signal source (G1) or sources (G1, G2) and includes a difference amplifier (A2) operative to produce an electrical signal having a linear relationship with a specified arithmetic function of the capacitances of the two capacitors (C1, C2). A touchless switch is implemented using the capacitance measurement apparatus. The touchless switch includes two sensor electrodes (E1, E2) that correspond to the two capacitors (C1, C2) under measurement and in one embodiment has a front surface in the form of a container.

A time-of-flight flow meter that is particularly useful for measuring the flow of gases, such as steam, uses a spark gap periodically energized with an electrical pulse to generate an acoustic pulse. The pulse is detected by upstream and downstream acoustic detectors that may be capacitive transducers having flexible plates wetted on both sides by the fluid so that no external venting is required. The acoustic detectors may be electrically heated to avoid condensation effects. In some cases the interior of the pipe or other conduit is shaped near the source so as to define acoustic beams aimed at the detectors and so as to concentrate the received acoustic energy on the detectors.