Abstract: An electrostatic encoder comprising receiving coupling electrodes formed on a scale, and extending in a predetermined direction, transmitting coupling electrodes provided on a sensor head, and located to face the receiving coupling electrodes, digital electrodes provided on the scale to extend from the receiving coupling electrodes in a direction perpendicular to the predetermined direction, and arranged at a predetermined pitch, two pairs of interdigital electrodes provided on the sensor head, and located to face the digital electrodes, a voltage applying portion configured to apply an alternating voltage to the transmitting coupling electrodes, and a potential difference detecting portion configured to detect a potential difference between the interdigital electrodes of each of the two pairs of interdigital electrodes.

Abstract: Circuits and methods for detecting and amplifying sensor and sensor array (102, 104) output signals are presented. According to some aspects, a nonlinear feedback loop containing a sensor element provides a nonlinear transformation that compensates for a corresponding nonlinear response of the sensor element thereby providing a linearized final output signal. In other aspects, idle sensors are coupled to a reference on non-idle sensor elements. Other aspects include sensor and amplification circuits which operate without traditional filtering or switching elements, such that a higher throughput is achieved and no settling time is required due to traditional transients, thus allowing for faster scanning of larger sensor arrays. Some embodiments of the present invention are directed to variable gap capacitive sensor arrays and the signal processing electronics.

Abstract: The invention relates to a flexible, resilient capacitive sensor suitable for large-scale manufacturing. The sensor includes a dielectric, an electrically conductive detector and trace layer on the first side of the dielectric layer including a detector and trace, an electrically conductive reference layer on a second side of the dielectric layer, and a capacitance meter electrically connected to the trace and to the conductive reference layer to detect changes in capacitance upon interaction with detector. The sensor is shielded to reduce the effects of outside interference.

Abstract: Cylindrical capacitance force sensing device/method is disclosed. In one embodiment, an apparatus includes a capacitor having two parallel conductive surfaces, a cylindrical housing with a cover plate to encompass the capacitor, and a sensor in the cylindrical housing to generate a measurement based on a change in a distance between the two conductive surfaces when the cover plate is deflected by a load applied on the cover plate. In another embodiment, a method may include applying a load on top of a housing which encompasses a capacitive sensor having two parallel conductive surfaces to produce a deflection of a cover plate of the housing, automatically generating a measurement from the capacitive sensor when a distance between the two parallel conductive surfaces is charged due to the deflection of the cover plate, and decreasing an error in the measurement via stabilizing to a mounting surface.

Abstract: A method for monitoring the depth of at least one via (11) in a wafer including the steps of arranging the via (11) as a capacitive plate (21), providing a corresponding capacitive plate (23), applying an electrical potential difference to the via (11) and the corresponding capacitive plate (23), measuring the resultant capacitance between the via (11) and a corresponding capacitive plate (23) and determining the depth of the at least one via (11) by the capacitance.

Abstract: Various alternative embodiments of a multi-turn capacitive encoder device are disclosed. The device includes two members that are fixed relative to each other and that include respective capacitive electrodes that are capacitively coupled between the two members. The respective capacitive electrodes on one member act as transmitter electrodes and the respective capacitive electrodes on the other member act as receiver electrodes. One or more modulation members are relatively movable between the two fixed members to alter or modulate the capacitive coupling to correspond to the rotational or angular position of the modulation member(s). At least one of the modulation members is driven using a gear reduction system such that its angular or rotational position corresponds to a plurality of turns of the input shaft of the multi-turn encoder.

Abstract: A multiple sensitivity stud sensing device for determining a location of objects behind a wall lining has a housing with a surface for moving over the wall lining. Within the housing are a capacitive sensor with first and second capacitances provided adjacent the surface and control circuitry. The control circuitry includes a detecting circuit connected to the sensor for providing a detection signal related to an imbalance between the first and second capacitances, a comparator having a reference signal for providing a comparator signal related to a difference between the detection signal and the reference signal, and a controller for receiving the comparator signal and providing a display signal. A display is provided on the housing for indicating a location of an object behind the wall lining. An input device is provided on the housing so that a user of the device can select a value for the reference signal.

Abstract: A method for non-contact measurement of a displacement between a surface and a capacitive sensor comprised of at least two superimposed conductive plates electrically insulated one from the other and a sensor circuit coupled to the plates including: positioning the capacitive sensor proximate to the surface such that the displacement is a distance of a gap between the surface and one of the plates; applying a high frequency signal to the plates; applying the high frequency signal and a sensor plate to control a voltage gain of an amplifier in the circuit, where the capacitance on the sensor is indicative of the displacement between the sensor and surface; differentiating an output of the amplifier and the high frequency signal, and determining a value of the displacement based on the difference between the output of the amplifier and the high frequency signal.

Abstract: A capacitance sensor system and method includes a capacitive sensor as an array of sensor electrodes near the surface of the integrated circuit and charge pump circuits for measuring the capacitance at each sensor electrode. Shield electrodes and unused sense electrodes are used for background capacitance cancellation at each array location. The shield electrodes are switched between the circuit supply potentials in a manner synchronous to the capacitance sensing at the sense electrodes. The improved background capacitance cancellation allows all circuitry to be located outside the sensor array. The capacitance data is used to determine the positions of fingerprint artifacts and other fingerprint features.

Abstract: A measuring apparatus having a probe that faces a surface of a target and is configured to supply AC current to the surface, measuring a voltage drop through a space between the probe and the surface, and obtaining a distance between the probe and the surface in accordance with the measured voltage drop. The apparatus includes a ground member facing, and apart from, the surface and configured to ground the surface by capacitive coupling, and a stage configured to hold either of the target and the probe and to move to define a measurement area on the surface. The ground member is configured so that the ground member faces all areas of the surface with respect to each of a plurality of measurement areas on the surface defined by a position of the stage.

Abstract: The method and a device to measure the repeatable and non-repeatable runouts of a rotating component of a spindle motor with the aid of at least one probe measuring changes in the distance between the probe and the rotating component depending on the angle of rotation. The probe records a first test signal in a first test cycle from which a signal defining the RRO is determined and stored. In a second test cycle, a command signal proportional to the amplitude and phase of the RRO signal is generated and fed to an electromechanical actuator supporting the probe. Depending on the command signal derived from the first test signal, the actuator changes the distance between the probe and the outer perimeter of the rotating component, thus compensating the runout defined by the RRO signal, while the probe records a second test signal defining the NRRO.

Abstract: An apparatus comprising a substrate and a MEM device. The MEM includes a comb capacitor and a magnetic element physically connected to one electrode of the comb capacitor. The magnetic element is capable of moving the one electrode in a manner that alters a capacitance of the comb capacitor. The apparatus also includes at least one spring physically connecting the magnetic element to the substrate.

Abstract: A circuit for detecting a difference in capacitance between a first capacitor and a second capacitor provided in a sensor includes an oscillator configured to generate an oscillating signal, a phase comparator coupled to the oscillator to output a signal responsive to a phase difference between the oscillating signal delayed by the first capacitor and the oscillating signal delayed by the second capacitor, an integration circuit coupled to the phase comparator to output an integrated signal made by integrating the signal responsive to the phase difference over a time period equal to a predetermined number of cycles of the oscillating signal, and a sample-and-hold circuit coupled to the integration circuit to output a signal made by sampling and holding the integrated signal at substantially an end of the time period.

Abstract: A probe device 20 having a contact load monitoring device 10. This contact load monitoring device measures the displacement of a loading table caused by a contact load exerted on the mounting table from a probe in an overdrive by means of a displacement sensor 11 disposed in the space below the mounting table as a sinkage quantity. This sinkage quantity is collated with a correlation table to determine the contact load. If the contact load is less than the designed contact load, the mounting table is further overdriven.

Abstract: A proximity sensor module includes a housing; and a proximity sensor disposed in the housing, wherein the proximity sensor comprises a sensor plate configured to contact inside of the housing such that substantially no gap exists between the sensor plate and the housing. The housing may be a substantially explosion-proof housing. The housing may include two members coupled by a thread engagement, wherein a sensor plate of the proximity sensor is placed off-center with respect to an axis of rotation for the thread engagement.

Abstract: A multi tip clearance measurement system is provided. The clearance measurement system includes a sensor disposed on a first object, wherein the sensor comprises a plurality of probe tips configured to generate signals representative of a sensed parameter corresponding to a second object and a processing unit configured to evaluate the signals from subsets of the sensed parameters from the probe tips to detect an outlier probe tip and to adjust a gain, or an offset of the respective outlier probe tip for estimating the clearance between the first and second objects based upon the signals.

Abstract: A measuring apparatus having a probe that faces a surface of a target and is configured to supply AC current to the surface, measuring a voltage drop through a space between the probe and the surface, and obtaining a distance between the probe and the surface in accordance with the measured voltage drop. The apparatus includes a ground member facing, and apart from, the surface and configured to ground the surface by capacitive coupling, and a stage configured to hold either of the target and the probe and to move to define a measurement area on the surface. The ground member is configured so that the ground member faces all areas of the surface, with respect to each of a plurality of measurement areas on the surface defined by a position of the stage.

Abstract: The invention relates to a flexible, resilient capacitive sensor suitable for large-scale manufacturing. The sensor comprises a dielectric, an electrically conductive detector and trace layer on the first side of the dielectric layer comprising a detector and trace, an electrically conductive reference layer on a second side of the dielectric layer, and a capacitance meter electrically connected to the trace and to the conductive reference layer to detect changes in capacitance upon interaction with detector. The sensor is shielded to reduce the effects of outside interference.

Abstract: The invention provides an electrostatic capacitance detection device. The electrostatic capacitance detection device can be formed of M individual power supply lines, N individual output lines, arranged in a matrix of M rows×N columns, and electrostatic capacitance detection elements provided on the crossing points of the individual power supply lines and the individual output lines, each of the electrostatic capacitance detection elements is formed of a signal detection element and a signal amplification element, the signal detection element is formed of a capacitance detecting electrode and a capacitance detecting dielectric layer, the signal amplification element formed of a metal-insulator-semiconductor (MIS) type thin film semiconductor device for signal amplification, including a gate electrode, a gate insulating layer and a semiconductor layer.

Abstract: A position transducer for a rotary member such as the rotor of a motor has a rotating encoder disc and flat, disc-shaped elements interacting with the encoder disc to produce position dependent signals. The encoder disc has at least one active element such as metal surfaces configured so that signals from one of several portions or sectors of the encoder system are not transferred to another portion or sector, thus permitting the position transducer to be split into several position detectors that can operate independently of each other without having signals from one position detector affecting the other position detectors. The position detectors can cover individual circular sectors or concentric rings and e.g. be based on sensing the capacitive coupling between transmitter and sensor electrodes located on opposite sides of the encoder disc.

Abstract: Structures for aligning wafers and methods for operating the same. The structure includes (a) a first semiconductor wafer including a first capacitive coupling structure, and (b) a second semiconductor wafer including a second capacitive coupling structure. The first and second semiconductor wafers are in direct physical contact with each other via a common surface. If the first and second semiconductor wafers are moved with respect to each other by a first displacement distance of 1 nm in a first direction while the first and second semiconductor wafers are in direct physical contact with each other via the common surface, then a change of at least 10?18 F in capacitance of a first capacitor comprising the first and second capacitive coupling structures results. The first direction is essentially parallel to the common surface.

Abstract: An area-change sensing through capacitive techniques is disclosed. In one embodiment, a first conductive surface is substantially parallel to a second conductive surface. The first conductive surface may be moveable relative to the second conductive surface in a direction substantially parallel to the second conductive surface. A processing module may detect an overlap area between the first conductive surface and the second conductive surface. In addition, a reference surface may be substantially parallel to the first conductive surface and the second conductive surface. The processing module may be configured to measure a reference capacitance between the reference surface and a selected surface of the first conductive surface and the second conductive surface.

Abstract: A technique for operating a sensor system is provided. The method includes exciting a first sensor with a first excitation signal at a first frequency and exciting a second sensor with a second excitation signal at a second frequency. The technique also includes combining a first measurement signal generated from the first sensor with a second measurement signal generated from the second sensor to determine a sensed parameter. The technique may be employed for reducing crosstalk between closely proximate sensors, such as capacitive probes, and may serve to determine distances within operating machines, such as turbine systems.

Abstract: An X-ray imaging apparatus includes an X-ray irradiating unit configured to irradiate an X-ray to an object, an X-ray detecting unit configured to detect the irradiated X-ray, an image creating unit configured to create X-ray image data based on data detected by the X-ray detecting unit, a moving mechanism configured to move the X-ray detecting unit to the object, a capacitance sensing unit, including an electrode which is positioned so as to cover at least part of a detection plane of the X-ray detecting unit, configured to obtain a capacitance value of the X-ray detecting unit by the electrode and a distance measurement unit configured to measure a distance between the object and the X-ray detecting unit based on the capacitance value.

Abstract: A paper dispenser having a proximity detector for dispensation of paper therefrom. The dispenser includes a housing having an inner chamber adapted to support a roll of paper. The housing also has a dispensing aperture. A motor is adapted to dispense paper from the roll through the dispensing aperture. The dispenser also includes a proximity detection circuit, which comprises an antenna, an oscillator circuit to charge the antenna, an operational amplifier operated as a unity gain follower which receives an antenna signal from the antenna, a detector circuit which detects changes in the antenna signal, and a comparator which actuates the motor in response to changes in the antenna signal.

Abstract: An oversampling electromechanical modulator, including a micro-electromechanical sensor which has a first sensing capacitance and a second sensing capacitance and supplies an analog quantity correlated to the first sensing capacitance and to the second sensing capacitance; a converter stage, which supplies a first numeric signal and a second numeric signal that are correlated to the analog quantity; and a first feedback control circuit for controlling the micro-electromechanical sensor, which supplies an electrical actuation quantity correlated to the second numeric signal.

Abstract: A stud or joist sensor and associated sensing method using an amplitude and a ratio of capacitance measurements from a plurality of capacitive sensing elements. The sensor locates a feature of an object or discontinuity behind a surface or wall, such as an edge and/or a center of a stud behind the surface, a joist under a floorboard, a gap behind sheetrock, a metal conductor behind a surface or the like. The sensor may be moved over the surface, thereby detecting changes in capacitance. The change in capacitance is due to the effective dielectric constant caused by the passage over a hidden object such as a stud. When two capacitive sensing elements provide equivalent capacitance measures, the sensor is over a centerline of the stud. When a ratio of the capacitance measurements equals a transition ratio, the sensor is over an edge of the stud. When the sensor is over the stud and the capacitance measurements are low, the sensor is over a deep stud.

Abstract: The position of an object, which may be a user's finger, along a body is sensed capacitively. A measurement circuit meters the simultaneous injection of electrical charge into the two ends of the body, which may be shaped as a straight line or as a curve. A computing device computes the ratio of the relative changes in the amount of charge injected into each end of the element. The result of this computation is a one dimensional coordinate number plus a detection state indication, both of which can be fed to another functional element, such as an appliance controller, which interprets the coordinate and detection state as a command or measurement.

Abstract: A simple and robust variable coaxial capacitive sensor and detection method for monitoring the position of a rapidly reciprocating member such as a piston or displacer in a free piston Stirling engine. The coaxial capacitor of the present invention in a preferred embodiment thereof is configured to modulate capacitive electrode area rather than inter-electrode spacing and as a result a highly linear transfer function can be achieved. Also disclosed are detection methods which derive and process signals in connection with applications which have small sensor capacitance variations while suppressing stray capacitance error.

Abstract: One embodiment of the present invention comprises a sensor with a face having several tracks spaced apart from one another. One of these tracks has a first electrode and a second electrode separated by an electrically nonconductive gap. Also included is a detection device extending across the tracks to receive signals by capacitive coupling. Sensor circuitry electrically coupled to the tracks and the detection device is structured to generate a first number of bits from a sequential signal pattern applied to the tracks in accordance with an established sequence. The circuitry is also structured to generate a second number of bits as a function of a first signal and a second signal. The first bits and second bits represent a position of the detection device along the tracks with the first bits being more numerically significant than the second bits.

Abstract: The movable apparatus of a positioning device comprising a conductive stationary part and a conductive movable part, the stationary part has an electrode constituting a capacitor together with said movable part, and the electrode is covered by a guard electrode insulated from the stationary part, whereby a triaxial structure is formed around these electrodes.

Abstract: A sensor for measurement of small-angle or small-displacement position of a rotational rheometer incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor array. The active rotor array is coupled to a drive shaft of the rotational rheometer and measured relative to the measurement and excitation arrays. The active rotor array is driven by an electrical signal that is precisely matched to signals detected by the measurement array. By driving the active array with signals sensed by the measurement array, the sensor allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: The invention provides a superior electrostatic capacitance detection device. An electrostatic capacitance detection device includes an M number of individual power-supply lines and an N number of individual output lines arranged in a matrix of M rows and N columns, and an electrostatic capacitance detecting element formed at the intersection thereof. The electrostatic capacitance detecting element includes a signal detection element and a signal amplifying element. The signal detection element includes a capacitance detecting electrode and a capacitance detecting dielectric layer. The signal amplifying element includes an MIS thin-film semiconductor device for signal amplification, including a gate electrode, a gate insulator, and a semiconductor layer.

Abstract: Aspects of the invention can provide an electrostatic capacitance detection device having M number of row lines and N number of column lines arranged in a matrix of M rows and N columns, and an electrostatic capacitance detection element formed at the intersection thereof. The electrostatic capacitance detection element can include a signal detection element, a signal amplifying element and a column selection element and a row selection element. The signal detection element can include a capacitance detecting electrode, a capacitance detecting dielectric layer, and a reference capacitor. One of a pair of electrodes in the reference capacitor is coupled to the row line. Accordingly, the invention can achieve a superior electrostatic capacitance detection device.

Abstract: One embodiment of the present invention includes a sensor with a face having several tracks spaced apart from one another. One of these tracks has a first electrode and a second electrode separated by an electrically nonconductive gap. Also included is a detection device extending across the tracks to receive signals by capacitive coupling. Sensor circuitry electrically coupled to the tracks and the detection device is structured to generate a first number of bits from a sequential signal pattern applied to the tracks in accordance with an established sequence. The circuitry is also structured to generate a second number of bits as a function of a first signal and a second signal. The first bits and second bits represent a position of the detection device along the tracks with the first bits being more numerically significant than the second bits.

Abstract: Capacitance element electrodes (E1 to E5) and a grounded reference electrode (E0) are formed on a substrate (20). A displacement electrode (40) that is Z-axially displaced in accordance with a Z-axial movement of a detective member (30) externally operated, is disposed so as to be opposed to the above electrodes (E0 to E5). The displacement electrode (40) cooperates with the reference electrode (E0) and the capacitance element electrodes (E1 to E5) to form capacitance elements (C0 to C5), respectively. Each of the capacitance elements (C1 to C5) is connected to the capacitance element (C0) in series in relation to an externally input signal. Changes in the capacitance values of the capacitance elements (C1 to C5) when the detective member (30) is moved, is detected by a signal processing circuit having hysteretic characteristics. Thereby, the displacement of the detective member (30) is detected.

Abstract: To provide a superior capacitance detecting device, a capacitance detecting device includes M row lines and N column lines that are arranged in a matrix, capacitance detecting elements provided at intersections therebetween, and power lines. The capacitance detecting element includes a signal detecting element and a signal amplifying element. The signal detecting element includes a capacitance detecting electrode, a capacitance detecting dielectric film, and a reference capacitor. The signal amplifying element is composed of a thin film semiconductor device having a gate electrode, a gate insulating film, and a semiconductor film, and an electrode of the reference capacitor is connected to the row line.

Abstract: A method for locating objects enclosed in a medium, according to which a detection signal is generated by at least one capacitive sensor device, the detection signal penetrating the medium that is to be analyzed in such a way that information is obtained about an object that is enclosed in the medium by evaluating the detection signal, particularly by measuring impedance, wherein, to obtain depth information about the object that is enclosed in the medium, an algorithm is used to evaluate the detection signal that calculates a compensation for drift effects of the capacitive sensor device that is generating the detection signal.

Abstract: A capacitance detecting circuit detects, in terms of voltage, change in capacitance at intersections of a plurality of column lines and a plurality of row lines crossing each other. The capacitance detecting circuit includes a column-line driving unit for driving a column line; a row-line selector for selecting a specific row line from the plurality of row lines; and a capacitance calculator for calculating a capacitance at an intersection of the specific row line and the driven column line based on a reference current that flows in relation to a reference capacitance and a current that flows in relation to the capacitance at the intersection.

Abstract: An oscillatory or pulsed first signal is operatively coupled to a first electrode placed between a conductive heating element and a seating region of a seat containing the heating element. A second signal substantially equal to the first signal is operatively coupled to a second electrode placed between the heating element and the first electrode. An occupant in the seat is sensed from a response to the first signal, responsive to which a safety restraint system may be controlled. In other embodiments, the second signal is operatively coupled to an electrode placed proximate to a side of the heating element away from the seating region of the seat, the second electrode comprises a sheath at least partially around at least a portion of the heading element, or the operative coupling of the first or second signals comprises AC coupling, for example, through an associated first or second capacitor.

Abstract: The invention relates to a measuring device including at least one measuring probe, sequentially applying a controlled supply voltage between the measuring probe and a reference element, and integrating accumulated electric charges on the measuring probe. The device also includes at least one auxiliary measuring probe, which is also sequentially linked to a controlled electric supply and to charge integrating means. The auxiliary measuring probe has a capacity, in relation to a potential detection zone, which is different from the main measuring probe. Comparative use of signals respectively emitted by the two measuring probes enables the influence of the main measuring probe to be determined.

Abstract: An electrostatic capacitance sensing device of exemplary embodiments of the present invention include M number of row lines, N number of column lines that are arranged in a matrix of M rows and N columns, N number of path gates for output signal, and electrostatic capacitance sensing elements provided at the intersections between the row and column lines. The electrostatic capacitance sensing element includes a signal sensing element, a signal amplifying element, a column selection element, and a row selection element. The signal sensing element includes a capacitance sensing electrode and a capacitance sensing dielectric film. The path gate for output signal, the signal amplifying element, the column selection element, and the row selection element are made up of thin-film semiconductor devices.

Abstract: The present invention has the object of providing a charged particle beam irradiation method ideal for reducing the focus offset, magnification fluctuation and measurement length error in charged particle beam devices. To achieve these objects, a method is disclosed in the invention for measuring the electrical potential distribution on the sample with a static electrometer while loaded by a loader mechanism. Another method is disclosed for measuring the local electrical charge at specified points on the sample, and isolating and measuring the wide area electrostatic charge quantity from those local electrostatic charges.

Abstract: A semi-circular dielectric rotor is attached to a steering column for rotation with the steering column. Straddling the rotor but not contacting it are an excitation electrode member which generates an electric field and a receiver electrode member that outputs signals representative of the electric field and, hence, of the position of the steering column.

Abstract: The invention provides an electrostatic capacitance detection device. The electrostatic capacitance detection device can be formed of M individual power supply lines, N individual output lines, arranged in a matrix of M rows×N columns, and electrostatic capacitance detection elements provided on the crossing points of the individual power supply lines and the individual output lines, each of the electrostatic capacitance detection elements is formed of a signal detection element and a signal amplification element, the signal detection element is formed of a capacitance detecting electrode and a capacitance detecting dielectric layer, the signal amplification element formed of a metal-insulator-semiconductor (MIS) type thin film semiconductor device for signal amplification, including a gate electrode, a gate insulating layer and a semiconductor layer.

Abstract: A sensor for measurement of small-angle or small-displacement position incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor or linear array. The active array is coupled to a moving object and measured relative to the measurement and excitation arrays. The active array may be floating, grounded or driven by an electrical signal. However, driving the active array with signals sensed by the measurement array allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: A chip-type sensor against ESD and stress damages and contamination interference includes a substrate structure and a protection layer covering over the substrate structure. The protection layer includes, from bottom to top, a first layer for providing a first stress against the substrate structure, a second layer for providing a second stress against the substrate structure, and a third layer for providing a third stress against the substrate structure. The first stress and the third stress belong to one of a tensile stress and a compressive stress, and the second stress belongs to the other of the tensile stress and the compressive stress.

Abstract: A capacitance of a capacitor member, which varies according to a dynamic force such as an acceleration force imposed on the capacitor member, is detected by a detecting circuit. The detecting circuit is composed of an operational amplifier and a switched capacitor circuit connected in parallel to each other. A reset time (t), during which a feedback capacitor in the switched capacitor circuit is discharged, is set to satisfy the following formula: t>(?C+m)/n, where ?C is an initial capacitance of the capacitor member, and n and m are constant factors having values in certain ranges. By setting the reset time (t) according to the above formula, an amount of acceleration imposed on the capacitor member is accurately detected even when the capacitor member has a certain level of the initial capacitance.

Abstract: A non intrusive method and system for the dynamic measurement of a distance, or the variations over time thereof, constituting the thickness, or the variations thereof, of a thin compressible dielectric material located between one or several other closely spaced solid dielectric layers of constant thickness and a conductive or semi-conductive surface. This is achieved by positioning a capacitive sensor on the external layer of the dielectric material, the sensor being composed of two parallel plates electrically insulated from one another, feeding the first plate with a high frequency signal, measuring the voltage and current value over time generated by the high frequency signal between the plate of the sensor which is closest to the surface of the outer layer of dielectric material, and deducting the above distance or variations thereof.

Abstract: A capacitive sensor includes an electrode member with two spaced-apart electrodes and an air gap therebetween. A position reference plate, which can be straight for sensing linear position or curvilinear for sensing angular position, is disposed in the air gap, with the electrode member being attached to a moving component and the reference plate mounted on a stationary object or vice-versa. The reference plate is formed with an opening, the width of which varies throughout the length of the opening, so that the capacitance between the electrodes varies depending on the position of the plate relative to the electrode member.