Abstract: A capacitive position sensor for detecting the position of an object relative to a resistive sensing element. The sensing element comprises a sensing path that has terminals connected along it that subdivide the sensing path into multiple sections. Each terminal is coupled to its own sensing channel, each of which generates a signal that is sensitive to the capacitance between its terminal and a system ground. The signals are fed to a processor for analysis. The processor determines over which section the object is positioned by comparing the signals from the sensing channels, and determines the position of the object within that section by comparing the signals from the terminals spanning that section. The sensing path can be formed in a closed loop, such as a circle for a scroll dial, in which the operator's finger position and movement can be uniquely determined in a straightforward manner.

Abstract: A capacitive touch sensor of the type employing adjacent drive and sense electrodes, in which an additional sense electrode Y1 is provided as well as the conventional drive electrode Xn and sense electrode Y0. The drive and two sense electrodes are arranged on the bottom side of a dielectric panel, the top side providing—a sensing surface to be touched by a user's finger or a stylus. The additional sense electrode is positioned on the underside of the dielectric panel so that it is shielded from the drive electrode by the conventional sense electrode. As a consequence, the conventional sense electrode is much more sensitive to the proximity of the finger or stylus than the additional sense electrode which primarily registers noise. The signal collected form the additional sense electrode is then subtracted from the signal collected from the conventional sense electrode, thereby to cancel noise.

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: A two-dimensional position sensor is formed by drive electrodes (52) and sense electrodes (62, 64, 66) both extending in the x-direction and interleaved in the y-direction. The sense electrodes comprise several groups, two of which co-extend in the x-direction over each different portions of extent in the x-direction. The drive and sense electrodes are additionally arranged to capacitively couple with each other. In use, drive signals are applied to the drive electrodes and then the resultant sense signals received from the sense electrodes measured. The position of a touch or stylus actuation on the sensor is determined in the x- and y-directions as follows. In the x-direction, the position is determined by an interpolation between sense signals obtained from co-extending pairs of sense electrodes, and in the y-direction by interpolation between sense signals obtained from different sequences of drive signals applied to the drive electrodes.

Abstract: A two-dimensional position sensor comprising a substrate with a sensitive area defined by a pattern of electrodes including electrodes for determining x-position and electrodes for determining y-position. The x-electrodes and y-electrodes generally extend in the x-direction and are interleaved in the y-direction. The x-electrodes comprise at least first, second and third groups of elements shaped such that adjacent ones of the elements of the different x-electrode groups co-extend in the x-direction so that the x-electrodes provide ratiometric capacitive signals, thereby providing quasi-continuous x-position sensing across the sensitive area. In addition, the y-electrodes may be resistively connected or arranged in ratiometric pairs to provide quasi-continuous y-position sensing. Alternatively, the x-electrode groups may be interdigitated to form pairs of x-adjacent blocks of differing area to provide stepwise x-position sensing in combination with stepwise y-position sensing provided by the y-electrodes.

Abstract: In one embodiment, a touch sensor includes drive electrodes. The drive electrodes include drive electrode structures that are each coupled to an adjacent drive electrode structure by a first strip of conductive material. The touch sensor also includes sense electrodes. The sense electrodes include sense electrode structures that are each coupled to an adjacent sense electrode structure by a second strip of conductive material. The sense electrode structures are formed on a same layer as the drive electrode structures. The first or second strip of conductive material include one or more conductive crossovers that each couple two drive electrode structures to each other or couple two sense electrode structures to each other.

Abstract: Noise reduction in a one- or two-dimensional capacitive sensor array is achieved by rejecting and re-acquiring noisy signals. The sensor array is formed of crossed X and Y lines for drive and sense functions respectively, each of the X lines being driven in turn to acquire a full frame of data from the sensor array. A controller actuates the X lines in turn and, for each X line, charge is transferred to charge measurement capacitors connected to respective ones of the Y lines. The controller measures a signal value from a first one of the measurement capacitors, and then tests if that Y signal value has a magnitude lying within an acceptable range. If not, the measurement capacitors are all reset without their signal values being measured, and the controller re-drives the same X line to initiate another charge transfer into the measurement capacitors for that X line. It is then attempted once again to acquire Y signal values for that X line.

Abstract: A touchscreen includes touchscreen electrode elements distributed across an active area of a substrate, and the touchscreen overlays a display. The touchscreen electrode elements are configured to avoid creating moiré patterns between the display and the touchscreen, such as angled, wavy, zig-zag, or randomized lines. In a further example, the electrodes form a mesh pattern configured to avoid moiré patterns.

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: In one embodiment, an apparatus includes a display and a first and second substrate. Each substrate has a surface facing toward the display; a surface facing away from the display; and drive or sense electrodes of a touch sensor disposed on the surface of each substrate facing away from the display. The drive or sense electrodes are made of a conductive mesh of conductive material. The apparatus also includes an adhesive layer between the first and second substrates.

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: A touch sensor senses the presence of an object at one of a plurality of channels on a surface of the touch sensor, wherein proximity of the object to the touch sensor results in a change in capacitance at the position of the channel. The touch sensor includes a drive circuit and a charge sensing circuit, each coupled to each of the channels. The charge sensing circuit includes at least one charge measurement capacitor. A measurement cycle is applied to the touch sensor having a drive portion and a sense portion. During the drive portion a charge is applied to the channels and therefore the charge measurement capacitors of the touch sensor, and during a sense portion the charge measurement capacitors are discharged by a predetermined amount and the remaining charge on the charge measurement capacitors is measured.

Abstract: A method includes performing a measurement burst which generates signal sample values from measurement cycles. Each measurement cycle includes inducing charge onto a key during a drive part of the measurement cycle, measuring during a signal measurement part of the measurement cycle the charge induced on the key during the drive part of the measurement cycle, and generating a signal sample value to represent the charge measured from the key. The method includes comparing the value of the signal sample values of the measurement burst with a determined range of accepted values between a determined maximum and a determined minimum value, and processing the signal sample values, which are outside the determined accepted range to the effect that the presence of the body can be determined only from a change in the value of one or more of the signal samples which are within the determined accepted range.

Abstract: A capacitive touch sensor employing adjacent drive and sense electrodes, in which an additional sense electrode is provided as well as a conventional drive electrode and sense electrode. The drive and two sense electrodes are arranged on the bottom side of a dielectric panel, the top side providing a sensing surface to be touched by a user's finger or a stylus. The additional sense electrode is positioned on the underside of the dielectric panel so that it is shielded from the drive electrode by the conventional sense electrode. The signal collected from the additional sense electrode is subtracted from the signal collected from the conventional sense electrode to cancel noise.

Abstract: An iterative method may comprise obtaining a current input signal value for a current iteration, comparing the current input signal value with an output signal value determined in a previous iteration, updating a counter value determined in the previous iteration based on the comparison such that the updated counter value replaces the previously determined counter value, determining a slew value based on the counter value, and adding the slew value to the previously determined output signal value to generate a new current output signal value. Different slew values may be added to the previous output signal to obtain a new output signal. The counter value is updated to reflect recent trends in the input signals. For example, if the input signal is on an upward trend, the counter value may be relatively high because it is incremented each time an input signal exceeds a previously determined output signal.

Abstract: Method and apparatus are provided for a capacitive sensor. In an example, a capacitive sensor can include a first sensing element, a sensing channel operable to generate a first signal indicative of first capacitance between the sensing element and a system ground, and a processor responsive to a change in the first capacitance between the first sensing element and ground. The processor can be configured to adjust a parameter value based on a first duration of the change in the first capacitance.

Abstract: In one embodiment, a method includes receiving one or more first signals indicating one or more first capacitive couplings of an object with a sensing element that comprises a sensing path that comprises a length. The first capacitive couplings correspond to the object coming into proximity with the sensing element at a first position along the sensing path of the sensing element. The method includes determining based on one or more of the first signals the first position of the object along the sensing path and setting a parameter to an initial value based on the first position of the object along the sensing path. The initial value includes a particular parameter value and is associated with a range of parameter values. The range of parameter values is associated with the length of the sensing path.

Abstract: In one embodiment, an apparatus includes a display and a first and second substrate. Each substrate has a surface facing toward the display; a surface facing away from the display; and drive or sense electrodes of a touch sensor disposed on the surface of each substrate facing away from the display. The drive or sense electrodes are made of a conductive mesh of conductive material. The apparatus also includes an adhesive layer between the first and second substrates.

Abstract: A method and apparatus for sensing the presence of a body from a change in an amount of charge present on a capacitively charged key includes performing a measurement burst which generates a plurality of signal sample values from a plurality of measurement cycles. Each of the measurement cycle includes inducing charge onto the key during a drive part of the measurement cycle, measuring during a signal measurement part of the measurement cycle the charge induced on the key during the drive part of the measurement cycle, and generating a signal sample value to represent of the charge measured from the key during the signal measurement part of the measurement cycle.

Abstract: A capacitive position sensor for detecting the position of an object relative to a resistive sensing element. The sensing element comprises a sensing path that has terminals connected along it that subdivide the sensing path into multiple sections. Each terminal is coupled to its own sensing channel, each of which generates a signal that is sensitive to the capacitance between its terminal and a system ground. The signals are fed to a processor for analysis. The processor determines over which section the object is positioned by comparing the signals from the sensing channels, and determines the position of the object within that section by comparing the signals from the terminals spanning that section. The sensing path can be formed in a closed loop, such as a circle for a scroll dial, in which the operator's finger position and movement can be uniquely determined in a straightforward manner.