Abstract: Apparatuses and methods of mutual-capacitance sensing with a capacitance-sensing circuit, such as a self-capacitance sensing device (CSD). One apparatus includes an input node coupled to a capacitance sense pin to couple to a first electrode of a sense array, a transmit (TX) signal generation circuit to generate a TX signal to drive a second electrode of the sense array, logic circuitry coupled to the TX signal generation circuit and the input node. The logic circuitry is configured to selectively couple a first capacitor to the input node and a second capacitor to the input node timed with the TX signal. The apparatus further includes an analog-to-digital converter (ADC) coupled to receive a receive (RX) signal from the input node and to convert the RX signal into a digital value, the digital value representing a mutual capacitance between the first electrode and the second electrode.

Abstract: A biometric finger sensor may include an array of biometric finger sensing pixels and an array shielding electrode outside the array of biometric finger sensing pixels. The biometric finger sensor may further include a finger drive electrode outside the array shielding electrode. Finger drive circuitry may generate a finger drive signal for the finger drive electrode and generate a compensating finger drive signal for the shielding electrode.

Abstract: The present invention provides a capacitor sensing circuit, comprising a driving unit, a switching unit, a differential integrator circuit, and a post-processing circuit. The driving unit is for providing driving signals and timing required by the capacitor sensing circuit, the switching unit switches signals according to two inverting timings, ?1 and ?2, the driving unit drives the capacitor sensing circuit, and together with the positive/negative input terminals of the differential integrator circuit, the signals are accumulated and integrated in both timing ?1 and ?2. The post-processing circuit receive the differential output of the differential integrator circuit for processing and/or utilizing the signals. The two timing signals are time-sharing signals in a period. Therefore, the capacitor sensing circuit is not effected by the common mode noise, and the accuracy and the sensibility are increased.

Abstract: A sensor device has a first electrode structure and a second electrode structure, the first electrode structure has a transmitting electrode, a compensation electrode and a reception electrode and the second electrode structure has a field transmission electrode and at least one field sensing electrode. The first electrode structure is adapted to detect a gripping of an electric hand-held device, whereas the second electrode structure is adapted to detect an approach of a finger to the second electrode structure, for example of the hand gripping the hand-held device.

Abstract: An electronic device includes a touch panel and a position detection circuit operable to output a position signal indicating a position at which the touch panel operated with an object. The detection circuit is operable perform a correction process to capacitance measurement values of electrodes of the touch panel to provide capacitance correction values. The detection circuit is operable to determine whether or not the electronic device is in a holding status in which the electronic device is held based on the capacitance measurement values or the capacitance correction values. The detection circuit is operable to perform a calibration process to correct the correction process if determining that the electronic device is in the holding status. The detection circuit is operable to output the position signal based on the capacitance measurement values or the capacitance correction values. This electronic device can avoid a false detection in approaching detection.

Abstract: In one embodiment, a method includes deactivating an integrator of a mutual-capacitive measurement circuit and configuring the mutual-capacitive measurement circuit according to a first voltage configuration. The first voltage configuration results in a charge on a sensor capacitor and a compensation capacitor when a supply voltage is applied to the mutual-capacitive measurement circuit. The method also includes adjusting a variable reference voltage input of the integrator to a first reference voltage, wherein the first reference voltage is selected to increase an output range of the mutual-capacitive measurement circuit. The method also includes applying the supply voltage to the mutual-capacitive measurement circuit and obtaining a first reference measurement from an analog-digital-converter coupled to an output of the mutual-capacitance measurement circuit.

Abstract: Roll-to-roll processes for manufacturing touch sensors on a plastic base film are provided. The touch sensors can be deposited on the base film using various patterning techniques. One or more shorting bars can also be patterned onto the base film to couple together traces, such as drive lines, sense lines, conductive traces, and the like, of the touch sensor to prevent a potential difference from forming between traces due to static buildup during the manufacturing process. After the touch sensor is fully formed on the base film, the touch sensor can be removed from the base film using lithography or a physical cutting process. The removal process can separate the touch sensor from the one or more shorting bars, thereby uncoupling the traces of the touch sensor.

Abstract: Ends on one side of physical quantity detection sensors formed of any of an electric charge generation-type sensor and a capacitance change-type sensor can be connected to negative electrode input terminals of a differential amplifier circuit, and ends on the other side are connected to positive electrode input terminals of the differential amplifier circuit. A feedback resistor and a feedback capacitor are connected in parallel between the negative electrode input terminal and an output terminal of the differential amplifier circuit, and a cancel resistor and a cancel capacitor are connected in parallel between a reference voltage and the positive electrode input terminal of the differential amplifier circuit. Drain voltage adjustment circuits can be provided that adjust the drain voltage of at least one of two field effect transistors to which positive and negative differential inputs of the differential amplifier circuit are individually inputted.

Abstract: An integrated circuit for compensating for parasitic capacitance in a capacitive measuring apparatus wherein a capacitance measurement is done by repeatedly transferring charge from a capacitor to be measured to a reference capacitor.

Abstract: A testing apparatus for testing whether an occupant detection sensor normally operates is disclosed. The testing apparatus includes: a ground that is an electrically-conductive structural member of the seat; an electrode plate that is electrically-conductive and is on the seat at a time of testing; multiple capacitors that are electrically connected between the electrode plate and the ground and are different in electrostatic capacity from each other; a switch mechanism that selects and switches one capacitor of the multiple capacitors; and a determination result check portion that determines, while switching the one capacitor by the switch mechanism, whether a signal outputted from the occupant detection sensor is a determination result corresponding to the switched one capacitor.

Abstract: A compensating circuit which has a programmable capacitance array for measuring AC voltage is disclosed in the present invention. The compensating circuit includes a pair of first leads for linking to an AC circuit; a variable capacitor, electrically linked to the first leads, for providing different capacitance value according to a programmable capacitance array; and a control unit, electrically linked to the first leads, for changing the capacitance value of the variable capacitor as one capacitance of the programmable capacitance array according to an external instruction. Since the capacitance of the compensating circuit is changeable, and AC voltage meter designed with the compensating circuit is able to measure voltage in wider range of frequency.

Abstract: An electrostatic capacitance detection circuit includes a charge amplifier that has an operational amplifier in which a capacitor is provided on a feedback path, and into which a signal including detection of electric charge of an inter-electrode capacitor of a sensor electrode and electric charge due to an external noise, and a selection switch that can switch a direction of a capacitor that is connected to input and output terminals of the charge amplifier through a feedback path that switches the direction of the capacitor depending on a direction of electric charge flowing in from a detection-side electrode of the sensor electrode, due to a drive signal applied to the sensor electrode.

Abstract: An impedance detection circuit includes a detection circuit, a correction circuit, a subtraction circuit, and an AC signal generator. The detection circuit has a first operational amplifier having an inverting input terminal coupled with one end of a signal line to whose other end a measured capacitor Cs is coupled, a non-inverting input terminal coupled with a shielding wire covering at least a part of the signal line and an output terminal of the AC signal generator, and an output terminal, and a second feedback resistor coupled between the output terminal and the inverting input terminal of the first operational amplifier. The correction circuit has a third resistor and a variable capacitor, and corrects a detection signal outputted from the first operational amplifier by adjusting a capacitance of the variable capacitor.

Abstract: In particular embodiments, an apparatus includes a charge-measurement capacitor having a first plate coupled to a second plate of a coupling capacitor and a non-transitory computer-readable storage medium embodying logic that is operable when executed to ground a first plate of the coupling capacitor; inject a pre-determined amount of charge onto the charge-measurement capacitor; and transfer an amount of charge accumulated on the second plate of the coupling capacitor to the first plate of the charge-measurement capacitor. The charge accumulated on the second plate of the coupling capacitor is due at least in part to noise. The logic is also operable when executed to determine, through a measured voltage across the charge-measurement capacitor, the amount of charge.

Abstract: In a capacitance detecting device including an offset adjustment circuit for removing offset from charge transmitted to an integrator from a charge reading mechanism, the offset adjustment circuit includes a variable capacitance element switching the number of capacitative elements connected in parallel to a charge transmission line made up of a plurality of the capacitative elements and setting the number to a predetermined capacitance value; and a capacitative element for adjustment connected in parallel to the variable capacitance element and parallel, and having a capacitance value corresponding to the minimum value of the capacitative elements constituting the variable capacitance element. Driving is controlled so that offset removal is performed only N times (M>N; M and N are natural numbers) in the capacitative element for adjustment while offset removal is repeated M times in the variable capacitance element.

Abstract: A capacitance detector includes: a first capacitor with fixed base capacitance and variable capacitance; a second capacitor charged with base charge corresponding to the base capacitance; third and fourth capacitors which receive capacitance distribution from the first or second capacitor; a first switching means for charging the first and second capacitors to a first fixed voltage and charging the third and fourth capacitors to a second fixed voltage in a first section and for charging the first and second capacitors to the second fixed voltage and charging the third and fourth capacitors to the first fixed voltage in a second section; a second switching means for separating the first and second capacitors from the third and fourth capacitors and for connecting the first and second capacitors to the third and fourth capacitors; and a differential amplifier to which first and second voltages corresponding to equalized charge are differentially input.

Abstract: The capacitive measuring circuit for a moved elongated test material contains at least two measuring capacitors, each of which is configured for receiving the test material. It further contains electrically actuatable selection means, by means of which one of the measuring capacitors can be selected in such a way that only the selected measuring capacitor contributes to the measurement, whereas the other measuring capacitors do not. As a result, the total capacitance of the measuring circuit is reduced and its sensitivity is increased.

Abstract: A method for detecting capacitor variation in a device comprises operating an oscillator in the device, the oscillator being an Inductive-Capacitive (LC) oscillator and including an inductor of known value and a capacitor under test, comparing an output of the oscillator to a reference output, and evaluating variation for a plurality of capacitors in the device based on the comparing.

Abstract: In a capacitive sensor of the type having X electrodes which are driven and Y electrodes that are used as sense channels connected to charge measurement capacitors, signal measurements may be made by driving the X electrodes to transfer successive packets of charge to the charge measurement capacitors. An additional noise measurement may be made by emulating or mimicking the signal measurement, but in certain embodiments without driving the X electrodes. The packets of charge transferred to the charge accumulation capacitor may be indicative of noise induced on the XY sensing nodes. These noise measurements can be used to configure post-processing of the signal measurements.

Abstract: A voltage measurement circuit is operative to measure a high voltage AC signal and includes a capacitive divider circuit and a compensator circuit. The capacitive divider circuit includes first and second inputs, across which, in use, is received a high voltage AC signal and also includes second and third capacitors. First and second plates of each of the first, second and third capacitors are defined by conductive layers of a printed circuit board and the dielectric of each of the first, second and third capacitors being defined by a non-conducting part of the printed circuit board. A compensator circuit has a configurable transfer function and includes an input connected across the first and second plates of the third capacitor and an output. The compensator circuit is operative to change a voltage received at its input in accordance with the transfer function and to provide the changed voltage at its output.

Abstract: An object of the invention is to provide a fuel-aspect sensor having higher detection accuracy. A first electrode is inserted into a hole formed in a first housing member. A cylindrical second electrode is inserted into and firmly fixed to the first electrode by a cylindrical insulating member. A first elastic member, for example, made of rubber, is arranged between the first electrode and a second housing member. The first electrode has a large-diameter portion, which is biased by the first elastic member toward a sealing surface formed on an inner wall of the hole, so as to fluid-tightly seal a space between the first electrode and the second housing member.

Abstract: A capacitive occupant detection system comprises at least one antenna electrode to be arranged in a seat and an evaluation unit operatively coupled to said at least one antenna electrode, said evaluation unit being configured for applying, during operation, an alternating voltage signal to said antenna electrode and for detecting an amplitude and/or phase of a displacement current flowing from said antenna electrode towards ground. According to the invention said antenna electrode comprises an antenna electrode conductor and at least one dedicated ground electrode, said ground electrode being arranged at a predetermined distance of said antenna electrode conductor and extending along said antenna electrode conductor.

Abstract: Circuitry is described for compensating leakage currents in capacitive sensing circuits. A single active leakage compensation circuit may sense a representative leakage current and drive a plurality of output transistors, each of which provides a compensating current to a respective capacitive sensing circuit. The leakage compensation circuit may sense current flow through a device substantially equivalent to a device exhibiting leakage current in a capacitive sensing circuit, and in response, provide a signal to drive one or more output transistors to supply approximately equivalent currents to a plurality of circuit nodes. For embodiments having multiple similar capacitive sensors and capacitive sensing circuits, only one transistor need be added to each capacitive sensing circuit to compensate for leakage current.

Abstract: A non-contact object detection system includes a capacitor sensor and a control system, the control system providing a AES (Adaptive Excitation Signal) to the capacitor sensor, the AES (Adaptive Excitation Signal) configured according to an environment in which the capacitor sensor is deployed, the AES (Adaptive Excitation Signal) configured to produce a threshold voltage from the capacitor sensor to the control system in the environment when an object is not in a detection area of the capacitor sensor.

Abstract: A method for measuring for generating a touch capacitance measurement is provided. Gain and offset control signals are generated, where the gain and offset control signals are adjusted to compensate for base capacitance of a touch sensor. The gain control signal is applied to a touch sensor during a first phase of a clock signal, and the offset control signal is applied to an output circuit during a second phase of the clock signal. The output circuit is coupled to the touch sensor during the second phase of the clock signal. The touch capacitance measurement is generated by compensating for the base capacitance with the gain and offset control signals, and a gain is applied to the touch capacitance measurement.

Abstract: A method for detecting the presence, and/or determining the location, and/or detecting changes in the material properties, of a first object (4) within a predefined space (12) and compensating for the disturbance caused by a second object, where the method comprises the following steps: providing at least a first and a second electrode (6) capacitively coupled to each other; conductively applying an electrical signal to each of the first and second electrodes (6), the electrical signals being different for the first and second electrodes (6); for each of the electrodes (6) measuring the current signal through, and/or the voltage signal on, the electrode (6); deriving from the measured values an indication of the disturbance caused by the second object; and deriving from the measured values and the indication of the disturbance a disturbance-compensated indication of the presence, and/or the location, and/or changes in the material properties, of the first object (4).

Abstract: The present invention relates to a system for measuring a capacitor (C). A current source (12) is connected in parallel to the capacitor (C) between a supply plane (Vc) and ground (VGND) for providing a current to the capacitor (C). A voltage level-shift is connected between the supply plane (Vc) and the ground (VGND) in parallel to the capacitor (C) and in parallel to the current source (I2). The voltage level-shift senses a voltage across the electronic component (C) and provides a level-shifted output voltage Vout in dependence thereupon. The voltage level-shift comprises a resistor (RI) connected in series with a current source (II) and an output port interposed between the resistor (RI) and the current source (II). The current sources (I,) and (12) have opposite temperature coefficients such that the current provided to the electronic component is substantially constant.

Abstract: Disclosed is a capacitance sensor including: a capacitance-voltage/current converter which converts a capacitance value of a sense capacitor into a voltage signal or a current signal by using an input signal; a multiplier which applies a weight to an output signal of the capacitance-voltage/current converter and outputs the weighted output signal; and an accumulator which accumulates continuously the output signal of the multiplier.

Abstract: A touch sensor assembly having a selectable sensitivity level allows for a user to activate a touch sensor while wearing hand covers. The touch sensor assembly includes a touch sensor, a comparison unit, and a control unit. The touch sensor has a selectable sensitivity level, and detects a value corresponding to a capacitance of the touch sensor. The comparison unit has a predetermined threshold stored therein, and determines activation of the touch sensor if the detected value exceeds the predetermined value. The control unit is operable to select a sensitivity level of the touch sensor by varying the predetermined threshold by an amount unrelated to an environmental effect on the touch sensor.

Abstract: An embodiment of the present invention is directed to a method for reporting position information. Position information received from a plurality of capacitive sensors in an array of capacitive sensors is adjusted based on predetermined adjustment values to generate adjusted position information. Each predetermined adjustment value is associated with at least one of the plurality of capacitive sensors. A signal representative of the adjusted position information is generated. In another embodiment, the sensitivity of at least one of the capacitive sensors is adjusted based on the position of the at least one capacitive sensor within the array.

Abstract: Systems and methods are provided for remotely identifying and classifying materials based on their respective complex permittivity features. Materials of interest to be identified in later inspections are cataloged according to their respective complex permittivity features by applying electromagnetic fields to them and determining their complex permittivity features. That library of features is used to compare field measurements taken during an inspection to determine the presence of a material of interest and to identify it.

Abstract: A capacitive sensor may include a transmit electrode and a receive electrode capacitively coupled with the transmit electrode. A capacitance sensing circuit senses a capacitance between the transmit and receive electrodes by applying a signal to the transmit electrode and rectifying a signal induced at the receive electrode. A compensation circuit reduces the effect of a mutual and parasitic capacitances of the transmit and receive electrode pair by adding a compensation signal to the rectified signal.

Abstract: In a capacitance detecting device including an offset adjustment circuit for removing offset from charge transmitted to an integrator from a charge reading mechanism, the offset adjustment circuit includes a variable capacitance element switching the number of capacitative elements connected in parallel to a charge transmission line made up of a plurality of the capacitative elements and setting the number to a predetermined capacitance value; and a capacitative element for adjustment connected in parallel to the variable capacitance element and parallel, and having a capacitance value corresponding to the minimum value of the capacitative elements constituting the variable capacitance element. Driving is controlled so that offset removal is performed only N times (M>N; M and N are natural numbers) in the capacitative element for adjustment while offset removal is repeated M times in the variable capacitance element.

Abstract: An occupant detection system with noise reduction, a controller having noise reduction for an occupant detection system and a method for reducing noise in an occupant detection system. A high order digital filter is used to filter harmonics of a noise signal from an electrode signal used to determine an occupant presence or absence of the occupant. A way of sampling the electrode signal and the implementation of the high order digital filter cooperate such that the signal processing can be performed by a lower cost general purpose microprocessor as opposed to using a higher cost digital signal processor.

Abstract: A method of determining a measure of a total capacitance of one or more capacitive elements connected to an output of a switched mode power supply is described. The method includes generating a voltage control signal to cause an output voltage control signal age controller to sweep a voltage at the output of the switched mode power supply from an initial voltage value to a final voltage value. Sample values of a current at the output measured by a current sampler during the sweep of the output voltage are received, and an integrated current value representing a measure of the total capacitance using the received sample values is calculated.

Abstract: A capacitance sensing circuit may include a capacitive sensor configured to conduct a sensor current, a current source for supplying a compensation current to the capacitive sensor, and a current mirror that generates a mirror current based on a compensated sensor current, where the compensated sensor current represents a difference between the compensation current and the sensor current. A measurement circuit generates an output signal corresponding to the capacitance of the capacitive sensor.

Abstract: A capacitive sensor may include a transmit electrode and a receive electrode capacitively coupled with the transmit electrode. A capacitance sensing circuit senses a capacitance between the transmit and receive electrodes by applying a signal to the transmit electrode and rectifying a current waveform induced at the receive electrode. A compensation circuit reduces the effect of a mutual and parasitic capacitances of the transmit and receive electrode pair by adding a compensation current to the rectified current.

Abstract: A noise suppression method for a capacitance-to-voltage converter varies a sequence of sensing signal edges during a plurality capacitance measurements to produce a number of noise responses. The sensing signal edges are varied in a repetitive rising and falling edge pattern for each sequence. Three or more such sequences can be used, and the sequence with the highest noise is eliminated and the others are averaged. The noise suppression method can be implemented during calibration and then used for a number of normal acquisitions. The noise suppression method can be applied to capacitance-to-voltage converters having monitoring and integration phases.

Abstract: An embodiment of the present invention is directed to a method for processing a position signal. The method includes receiving a first position signal from a capacitive sensor and determining a proximity of the capacitive sensor to a connection of an array of capacitive sensors. The sensitivity of the capacitive sensor is then adjusted and a second position signal is received from the capacitive sensor. The second position signal may then be reported. The present invention facilitates more accurate readings from an array of capacitive sensors.

Abstract: Circuits and methods for compensating the impact of parasitic capacitances on capacitive sensors have been achieved. The charge of a compensation capacitor assigned to each capacitive sensor is used to neutralize the charge of the parasitic capacitor.

Abstract: In a capacitive sensor of the type having X electrodes which are driven and Y electrodes that are used as sense channels connected to charge measurement capacitors, signal measurements are made conventionally by driving the X electrodes to transfer successive packets of charge to the charge measurement capacitors. However, an additional noise measurement is made by emulating or mimicking the signal measurement, but without driving the X electrodes. The packets of charge transferred to the charge accumulation capacitor are then indicative of noise induced on the XY sensing nodes. These noise measurements can be used to configure post-processing of the signal measurements.

Abstract: A surface-conforming obscured feature detector includes a plurality of sensor plates, each having a capacitance that varies based on the dielectric constant of the materials that compose the surrounding objects and the proximity of those objects. A sensing circuit is coupled to the sensor plates 32 to measure the capacitances of the sensor plates. A controller is coupled to the sensing circuit to analyze the capacitances measured by the sensing circuit. One or a plurality of indicators are coupled to the controller, and are selectively activated to identify the location of an obscured feature behind a surface.

Abstract: An integrated circuit for compensating for parasitic capacitance in a capacitive measuring apparatus wherein a capacitance measurement is done by repeatedly transferring charge from a capacitor to be measured to a reference capacitor.

Abstract: A chemical impedance detector having several electrodes situated on or across a dielectric layer of a substrate. The electrodes may be across or covered with a thin film polymer. Each electrode may have a set of finger-like electrodes. Each set of finger-like electrodes may be intermeshed, but not in contact, with another set of finger-like electrodes. The thin-film polymer may have a low dielectric constant and a high porous surface area. The chemical impedance detector may be incorporated in a micro fluid analyzer system.

Abstract: A method for minimizing stray current in capacitive sensor data includes receiving a first input from a first wire of a wire harness, the wire harness comprising a plurality of twisted wires, the first input comprising a first signal comprising first sensor data and stray current; receiving a second input from a second wire of the wire harness, the second input comprising a second signal comprising stray current; and subtracting the second signal from the first signal to determine the first sensor data. A system for minimizing stray current in capacitive sensor data is also provided.

Abstract: Method for biomass determination in a medium, in particular a medium containing biological cells suspended in a conductive fluid, the biomass concentration (X) being obtained from a difference between a first capacitance signal (C?1) of the medium, measured at a first frequency, and a second capacitance signal (C?2) of the medium, measured at a second frequency. The method includes a separate correction of each of the measured signals, based at least on one correction level, the first correction level including a correction of the signals measured in accordance with a model dependent on the conductance of the medium at the first and second frequencies. The invention is useful in biomass measurement systems.

Abstract: The present invention relates to a capacitance sensing circuit with anti-EMI capability. A filter is coupled to a capacitor under test; receives a plurality of reference signals; and produces a first filter signal and a second filter signal. A difference circuit receives the first and second filter signals; eliminates the common-mode noise in the first and second filter signals; and produces a difference signal. The amplitude of the difference signal is related to the capacitance value of the capacitor under test. Thereby, the purpose of sensing capacitance can be achieved. In addition, by eliminating common-mode noise using the difference circuit, the anti-EMI capability can be achieved. Because the difference circuit can adjust the dynamic range of the output of the filter, the capacitance sensing circuit with anti-EMI capability can achieve capacitance sensing in few clock cycles.

Abstract: A low capacitance signal acquisition system has a signal acquisition probe having a low capacitance input circuit coupled to a compensation amplifier in a signal processing instrument via a signal cable. The low capacitance input circuit, the signal cable and the signal processing instrument input have mismatched time constants with the compensation amplifier having feedback loop circuitry providing adjustable gain and pole-zero pairs for maintaining flatness over the low capacitance signal acquisition system frequency bandwidth.

Abstract: A system includes a capacitive sensor including a first electrode and a second electrode. The system includes a measurement system configured to sense a capacitance between the first electrode and the second electrode and apply a first offset to the sensed capacitance to provide an offset compensated capacitance.

Abstract: Time-sloped capacitance measuring circuits use the time to ramp voltage signals between reference levels to determine an unknown capacitance, where the ramping time is determined by the cumulative whole number of clock cycles counted during voltage signal ramping over multiple ramp cycles. Measurement resolution can be improved by adjusting a starting voltage level for subsequent voltage signal ramps by an amount that compensates for incremental voltage ramping during a terminal clock cycle of a previous voltage signal ramp.