Abstract: A structure is presented in which it is easy to adjust, to a determined value, distance between electrodes of a condenser formed in an electrostatic capacity-type displacement sensor. A displacement sensor has a conductive lower layer, an insulating layer stacked on the conductive lower layer and a conductive upper layer stacked on the insulating layer. The conductive lower layer is divided into a first lower region and a second lower region by a groove penetrating the conductive lower layer. The insulating layer is stacked on the conductive lower layer at selected portions. The conductive upper layer is stacked on the insulating layer at selected portions. The conductive upper layer has a beam connected via the insulating layer to the first lower region and the second lower region at a pair of ends of the beam. The conductive upper layer has a first upper portion forming one of electrodes of a first condenser.

Abstract: A pair of identical humidity sensors (S1) and (S2) are in the same environment, so that they identically react to humidity effects; a sensing circuit includes an operational amplifier (10), its input (15) receiving from the first sensor (Si) a signal changing with humidity according to a logarithmic law, while the second sensor (S2), inserted in the amplifier feedback, reacts to humidity changes in the same way as the first sensor (Si) and consistently modifies the gain. The output signal (V0) is compensated, and has a substantially linear progression with humidity.

Abstract: 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.

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 located 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, and a processor for receiving the detection signals and providing a display signal. A display is located on the housing for indicating location of an object behind the wall lining. The processor compares a detection signal to stored predetermined threshold values of detection signals associated with different wall lining thicknesses and displays a thickness value to the user.

Abstract: A fixed electrode and a movable electrode to be used to drive each arm are formed at a drive unit. As a voltage is applied between the fixed electrode and the movable electrode, the movable electrode is caused to move by coulomb force, thereby driving the arm 3 in a closing operation. By detecting a change occurring in the electrostatic capacity between the fixed electrode and the movable electrode at this time, a decision can be made as to whether or not the sample has been gripped.

Abstract: Cost-effective methods and apparatus are disclosed for measuring both absolute position and fluctuations using a moving dielectric medium between fixed electrodes. A position sensor according to the invention includes a pair of spaced-apart electrodes, an elongated dielectric that moves between the electrodes, and electrical circuitry interconnected to the electrodes to determine the position of the dielectric relative to the electrodes. To realize a linear position sensor, the electrodes are electrically conductive rods or wires, and the dielectric is also an electrically non-conductive rod or wire. The dielectric may be flexible or stiff, in which case the dielectric and the electrodes are preferably substantially parallel to one another. Alternatively, the spaced-apart electrodes may be concentric tubes, with the dielectric being an electrically non-conductive tube slideably disposed between the electrodes. In different embodiments, the dielectric is a liquid-receiving tube.

Abstract: The technology features an apparatus and a method for sensing the length of a lead that connects to a power source to a thermal processing system such as a plasma torch system. Components disposed in the thermal processing system enable the length of the lead to be sensed. In addition, the time for contact starting a thermal processing system enables determination of the length of the lead.

Abstract: A device for measuring the thickness of print products in a conveying flow includes a plate capacitor having a first plate and a second plate located on opposite sides of the print products. The plate capacitor is adapted to measure capacitance of the print products passing between the first plate and the second plate. A LC oscillator circuit is attached to the plate capacitor.

Abstract: A method of sensing proximity to a showerhead in a semiconductor-processing system is provided. The method includes measuring a parameter that varies with proximity to the showerhead, as well as with at least one external factor. The method also includes measuring a parameter that does not vary with proximity to the showerhead, but does vary with the at least one factor. A compensated proximity output is calculated based upon the measured parameters and is provided as an output.

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: A method of detecting rubs during operation of a turbomachine comprising at least one rotating object having a tip and a shelf is provided. The method includes generating signals representative of a sensed parameter and processing the signals to generate height versus time data for the tip. The height of the tip corresponds to the distance between the tip and the shelf. The method further includes monitoring the height versus time data, in order to determine whether a change in the height data exceeds a threshold value, and detecting a rub of the rotating object(s) on a second object, when the change in the height data exceeds the threshold value. A rub detection system for a turbomachine and a turbine engine system with rub detection are also provided.

Abstract: A method is provided and includes exciting a sensor with an incident signal and generating a reflected signal by reflecting the incident signal from the sensor. The incident signal and the reflected signal interfere to form a standing wave. The method also includes processing the signals to determine a sensed parameter based upon a frequency at which the standing wave exhibits a null.

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: An embodiment of the present invention relates to a alignment measurement system for measuring alignment between a plurality of chips of a device, the chips being assembled in a three-dimensional stacking configuration and equipped with at least an integrated capacitive sensor, including a multiple-capacitor structure integrated in the capacitive sensor, at least a sensing circuit connected to the multiple-capacitor structure which issues an output voltage, proportional to a variation of a capacitive value of the multiple-capacitor structure of the integrated capacitive sensor of the device and corresponding to a measured misalignment between the chips of the device.

Abstract: A sensor for determining a position for an adjacent object in two dimensions is described. The sensor comprises a substrate with a sensitive area defined by a pattern of electrodes, wherein the pattern of electrodes includes a first group of drive elements interconnected to form a plurality of row electrodes extending along a first direction, a second group of drive elements interconnected to form a plurality of column electrodes extending along a second direction, and a group of sense elements interconnected to form a sense electrode extending along both the first and second directions. The sensor further comprises a controller comprising a drive unit for applying drive signals to the row and column electrodes, and a sense unit for measuring sense signals representing a degree of coupling of the drive signals applied to the row and column electrodes to the sense electrode. Thus a 2D position sensor requiring only a single sense channel is provided.

Abstract: “Electrical field (“E-field”) sensor systems that sense displacement or change in displacement of one body relative to another.” In general, the bodies 110, 112 are within an electrical field and displacement of a body causes a change in the E-field. A field sensor 290 detects this change and a processor 275 translates it to a change in position of the displaced body 110. The E-fields are generated by electrodes (or an electrode and a ground member) that generate the E-field. The systems include detectors 240 that detect changes in the E-field, such as capacitance, and transmit these to the processor 275.

Abstract: A capacitive proximity switch has an electrically conductive sensor surface, which is covered by an electrically non-conductive covering plate and which serves as a part of a capacitor with a capacitance that varies with proximity. The proximity switch includes a reference sensor surface for generating a reference signal for determining an actuation state of the proximity switch. Signal portions of the reference signal are proportional to the capacitance of a reference capacitor formed with the reference sensor surface, and the capacitance of the reference capacitor is determined by surrounding conditions of the sensor surface.

Abstract: A system for determining a distance between a showerhead of a semiconductor processing system and a substrate-supporting pedestal is provided. The system includes a showerhead having a showerhead surface from which reactive gas is expelled and a pedestal having a pedestal surface that faces the showerhead surface. A first capacitive plate is disposed on the pedestal surface. A second capacitive plate is disposed on the showerhead surface. A third capacitive plate disposed on one of the showerhead surface and the pedestal surface, but spaced from the first and second capacitive plates. Capacitance measurement circuitry is operably coupled to the first, second and third capacitive plates.

Abstract: The present disclosure provides several systems. In general, it provides E-field sensor systems that utilize at least one electrode 100 adapted for creating an E-field in an area 210 within a detection volume where fluid presence 400 or presence of a solid body 300 is to be detected. The electrical field sensor is configured to generate a detected signal responsive to a change in capacitance of the electric field, and is communicatively coupled to the electrode 100. In addition, a processor 275 is configured to determine a quantitative measure of a fluid or solid body within the detection volume in accordance with a capacitive relationship with the detection volume. Described are examples of the system for fluid presence detection, fluid level measurement and measurement of proximity to a solid object.

Abstract: A capacitive proximity switch has an electrically conductive sensor surface, which is covered by an electrically non-conductive covering plate and which serves as a part of a capacitor having a capacitance that varies with proximity. The sensor surface is connected to a control input of a semiconductor switch that has a signal input with a clock signal and a signal output. A household appliance is equipped with the capacitive proximity switch. The signal output of the semiconductor switch has an output signal, which follows the clock signal and which has signal portions that are proportional to the capacitance of the capacitor formed with the sensor surface.

Abstract: A sensor for sensing a gap between the sensor and an object of interest within a semiconductor processing chamber is provided. The sensor includes a housing, a power source inside the housing, wireless communication circuitry, a controller, measurement circuitry and a plurality of capacitive plate pairs. The controller and wireless communication circuitry are coupled to each other, and to the power source. The plurality of capacitive plate pairs are configured to form capacitors having a capacitance that varies with the gap. Measurement circuitry is coupled to the controller and to the plurality of capacitive plate pairs. The measurement circuitry is configured to measure the capacitance of the capacitive plate pairs and provide indications thereof to the controller. The controller is configured to provide an indication relative to the gap based, at least in part, upon the measured capacitances.

Abstract: A capacitive position sensor has a periodic array of electrodes which form capacitors between pairs of the electrodes. The location of a dielectric inhomogeneity in the vicinity of the sensor is determined by comparison of the relative change in the capacitance of the capacitors. The comparison may be carried out using a capacitive Wheatstone Bridge arrangement. The sensor configuration has the advantage that it is independent of the absolute value of the dielectric constant of the environment in which the sensor is located.

Abstract: The present invention relates to a system used for inspecting the position of a compressor rotor within a compressor rotor case. A compressor rotor blade is moved about the rotor blade path of the compressor rotor case, a probe holder attached to the rotor blade has a scanning device as part of the holder used for gathering information relative to the compressor rotor case. A fixture attached to the compressor rotor gathers information about the position of the compressor rotor with respect to the compressor rotor case to determine the relative position of both the compressor rotor in relation to the compressor rotor case.

Abstract: A device for measurement and detection of the level of a medium in a container with a sensor element, with a reference element and an electrical circuit which contains at least one AC voltage source and an evaluation unit, the sensor element and the reference element being arranged such that the medium to be measured or detected influences the impedance between them. The capacitive level measurement and detection device has an AC voltage source that supplies a high-frequency voltage or a voltage with high frequency voltage portions. The circuit which has the AC voltage source, the sensor element and the reference element has an impedance which is as low as possible. The electrical circuit can have an amplifier, a timer, a pulse shaper, a first synchronous rectifier, a first I/U converter, a microcontroller, a reference impedance, a second synchronous rectifier and a second I/U converter.

Abstract: A method of sensing absolute position of a structure includes: generating a signal pattern to repetitively provide a changing voltage to each of two or more tracks of a sensor, capacitively coupling an electrode of the sensor to the tracks to determine a first electrode position along the tracks by detecting a first group of signals emitted in response to the signal pattern, moving at least one of the electrode and the tracks relative to another of the electrode and the tracks to result in a second electrode position along the tracks different from the first electrode position, and detecting a second group of signals emitted in response to the signal pattern with the electrode capacitively coupled to the tracks to determine the second electrode position.

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: A blade tip clearance probe holder including: a first housing in operable communication with a first feature of a casing for a rotary machine; a spring rod assembly in operable communication with the first housing; an electrical capacitance clearance meter in operable communication with the spring rod assembly; and a second housing in operable communication with the first housing wherein the second housing initiates a preload on the spring rod assembly and wherein the electrical capacitance clearance meter maintains a constant spatial relationship with a second feature of the casing for the rotary machine.

Abstract: A sensor (1) for capacitively measuring the distance to a stationary or passing object. The sensor has an electrode (2) that capacitively couples with the object and is formed from an electrically conductive ceramic material. The electrode is substantially surrounded by a housing (4) formed from an electrically non-conductive ceramic. The electrically conductive and electrically non-conductive ceramic materials are chosen to that they have the similar thermal expansion coefficients so that the sensor remains virtually stress free at high temperatures.

Abstract: A deflector which enables to have a sufficient degree of freedom of designing and also to detect accurately a displacement angle of a movable plate can be provided. In order to accomplish this, the deflector includes a mirror, a base frame, a pair of torsion bars which pivotably support the mirror with respect to the base frame, a drive coil which is provided on the mirror, two permanent magnets which generate a magnetic flux which acts in the drive coil, two capacitive sensors which output an angle of oscillation of the mirror as electrical characteristics, a connecting portion which electrically connects on the mirror a first end out of two ends of the drive coil and one end of electric terminals of the two capacitive sensors, and a first wire which is drawn from the connecting portion up to the torsion bars via the base frame.

Abstract: A sensor assembly has a plurality of sensing elements configured to be positioned within a seat of a vehicle. Each of the sensing elements include an output signal indicating the presence or absence of an occupant. The sensor assembly includes a cable with a plurality of conductors that are in electrical communication with the output signals of the sensing elements. The sensor assembly further provides a non-conductive spacer positioned between the cable and the plurality of sensing elements. A method for providing a sensor assembly having a spacer between sensing elements and conductors attached thereto to reduce unwanted coupling of signals onto the conductors is also disclosed.

Abstract: A semiconductor die includes proximity connectors proximate to a surface of the semiconductor die. This semiconductor die is configured to communicate signals with another semiconductor die via proximity communication through one or more of the proximity connectors. In particular, the proximity connectors include a first group of proximity connectors that is configured to facilitate determining a first separation between the semiconductor die and the other semiconductor die by comparing coupling capacitances between the semiconductor die and the other semiconductor die. Note that the first group of proximity connectors includes a first proximity connector and a second proximity connector, and the second proximity connector at least partially encloses an in-plane outer edge of the first proximity connector.

Abstract: A passage detection apparatus 300 is configured to detect the change in the properties (propagation state of sound wave, dielectric constant, etc.) of a specific space 300a, which changes according to the passage of an object in the specific space 300a and the size of the object. The passage detection apparatus 300 includes a pair of detection units 310 and 320 configured to transmit and receive signals to and from an external device. The specific space 300a is formed by the space between the detection unit 310 and the detection unit 320. The detection unit 310 is supported by a first substrate 330. The detection unit 320 is supported by a second substrate 340 that is parallel to the first substrate 330, and arranged at the position corresponding to the detection unit 310 supported by the first substrate 330.

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: A relative-dielectric-constant measuring apparatus according to the present invention includes an ellipsometer and a capacitance measuring part. The ellipsometer allows non-contact measurements of the film thickness and optical constants of an insulation film formed on the upper surface of a wafer. The capacitance measuring part, on the other hand, allows non-contact measurements of the gap between the insulation film and an electrode and accumulation capacitance. The relative-dielectric-constant measuring apparatus can calculate the relative dielectric constant of the insulation film based on the measured film thickness, gap, and accumulation capacitance. Thus, the relative dielectric constant of the insulation film can be determined without contact and with high precision.

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: An electric potential fixing apparatus of the present invention is an electric potential fixing apparatus that is connected to a connection line (17) between two capacitances, the first capacitance (14) and the second capacitance (15) that is directly connected to the first capacitance, includes the first high resistance (3), the second high resistance (4) that is connected directly to the first high resistance, a voltage dividing unit that outputs electric potential divided by the first high resistance and the second high resistance to the output terminal, the third capacitance (8) that is connected in parallel to at least either of the first high resistance and the second high resistance, and a voltage supply unit (1) operable to maintain constantly electric potential of the connection line between the two capacitances (14) and (15), holding combined total electric charge quantity of the first capacitance and the second capacitance, and the output terminal of the voltage supply unit is connected to a signal

Abstract: By using techniques for near field probes to measure dielectric values of blanket films, the measure of the sidewall damage of the patterned structure is calculated. The interaction between the near field probe and the etched structure is modeled to obtain the model total capacitance. The near field microwave probe is calibrated on a set of blanket films with different thicknesses, and the dielectric constant of the etched trench structure is calculated using the measured frequency shift and calibration parameters. The measured capacitance is further calculated for the etched trench structure using the dielectric constant and the total thickness of the etched trench structure. The effective dielectric constant of the structure under study is extracted where the model capacitance is equal to the measured capacitance. The measure of the sidewall damage is further calculated using the effective dielectric constant.

Abstract: A shielding member is provided as an electrostatic protection device in extension lines that extend from a sensing area to switching devices via extension areas correspondingly. As a result, even if a body to be detected such as a finger contacts the extension area, it is possible to reduce the amount of the change of an electrostatic capacitance with respect to the movement of the body to be detected. Therefore, it is possible to reduce influences exerted on data to be detected, and an electrostatic detection apparatus having improved coordinate detection accuracy can be provided.

Abstract: In a method for locating objects enclosed in a medium, a detection signal is generated by at least one capacitive sensor. The detection signal penetrates the medium that is to be analyzed in such a way that information is obtained about the objects that are enclosed in the medium by evaluating the detection signal, particularly by measuring impedance. In order to evaluate the detection signal, an algorithm is used that separates the measured signal into signal parts originating from the enclosing medium and signal parts originating from the object enclosed in the medium. A measuring device carries out the inventive method.

Abstract: A sensor assembly has a plurality of sensing elements configured to be positioned within a seat of a vehicle. Each of the sensing elements include an output signal indicating the presence or absence of an occupant. The sensor assembly includes a cable with a plurality of conductors that are in electrical communication with the output signals of the sensing elements. The sensor assembly further provides a non-conductive spacer positioned between the cable and the plurality of sensing elements. A method for providing a sensor assembly having a spacer between sensing elements and conductors attached thereto to reduce unwanted coupling of signals onto the conductors is also disclosed.

Abstract: A fixed electrode and a movable electrode used to drive each arm are disposed at a drive unit. As a voltage is applied between the fixed electrode and the movable the electrode, a coulomb force causes the movable the electrode to move, thereby driving the arms along the closing direction. The dimensions of a sample can be measured based upon the electrostatic capacity achieved between the electrodes when the sample becomes gripped by the arms.

Abstract: An object sensing system (50), and method, employing electric field sensing, also known as quasi-electrostatic sensing and which may be termed cross capacitive sensing, is described. The system (50) includes at least one electrode arrangement (30), each electrode arrangement (30) includes one electric field sensing reception electrode (32) and two electric field sensing transmission electrodes (34, 36). One of the electric field sensing transmission electrodes (36) is driven with an alternating voltage (130) including at least some antiphase portions, for example an inverted signal, in comparison to an alternating voltage (120) with which the other electric field sensing transmission electrode (34) is driven. This improves the spatial precision of object sensing performed by detecting changes in the current induced in the electric field reception electrode (32).

Abstract: A measuring apparatus comprising: a reference member held in fixed position and orientation with respect to a workpiece during measurement; a stylus for scanning a surface of the workpiece while being displaced upward and downward in accordance with unevenness of the surface of the workpiece; a displacement gauge for measuring a displacement of a specific part of the stylus relative to the reference member; and a scanner for causing the stylus to scan the workpiece along the surface; wherein the fixed position and orientation of the reference member with respect to the workpiece are not changed even during the operation of the scanner; the up-and-down displacement of the specific part of the stylus is measured relative to the reference member; a fine shape of the workpiece is detected in accordance with the measured displacement of the specific part of the stylus.

Abstract: A sensor system comprising a sensor operable to provide an output signal representative of a sensed parameter is provided. The sensor system also comprises a control system coupled to the sensor, wherein the control system is operable to change a physical characteristic of the sensor based on the output signal representative of the sensed parameter.

Abstract: An unknown object shape is computed using repeated iterations of electrostatic calculations on a predetermined shaped object and sensed electrostatic measurements. The predetermined object shape is morphed toward the unknown object shape at each iteration until the object shape is determined. The morphing of the shape is based on calculating the zero contour of the electrostatic potential, which potential depends on a charge distribution applied to the predetermined shape.

Abstract: 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.

Abstract: A capacitive sensor, in particular for the detection of an obstruction of objects or body parts by motor driven devices, includes an arrangement of a multitude of electrodes on a support and means to measure a capacitance or a capacitance change. The sensor is of a flat and film-like embodiment with a support made out of a film material for the arrangement of the electrodes. Furthermore, a capacitive sensor system, for detection of an obstruction situation of objects or body parts with motor driven devices uses several sensors of the above design, is disclosed, whereby an obstruction situation is detected, if a selection of several sensors is responding.

Abstract: A measuring instrument has a phase signal transmitter that transmits, in accordance with a rotation of the spindle, a phase signal that differs corresponding to the rotation angle of the spindle, and an arithmetic processor that arithmetically processes the phase signal to obtain the absolute position of the spindle. The phase signal transmitter transmits the phase signal at a predetermined pitch. Since the phase signal differs corresponding to the rotation angle of the spindle, a rotation angle of the spindle is uniquely determined by the phase signal. Unlike an increment type measuring instrument, since there is no concern that the signal will be skip-read, the spindle can be rotated at high speed, so that operational performance of the micrometer can be improved. Further, since there is no concern that the signal will be skip-read, the phase signal can be minutely varied with respect to the rotation of the spindle.

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.