Microchip Technology Inc.

Neodron Limited

Jerry Hanauer

Todd O'Connor

Keith Edwin Curtis

Lance D Lamont

Attma Sharma

Cory Walton

James S Bartling

Padmaraja Yedamale

Improved signal-to-noise performance of projected capacitance touch screens and panels is provided by an integrated circuit regulated high voltage source and high voltage/current drivers coupled to a plurality of projected capacitive touch elements that are controlled by a microcontroller. The single integrated circuit high voltage generator/driver may comprise a voltage boost circuit, a voltage reference, power-on-reset (POR), soft start, a plurality of voltage level shifters and a serial interface for coupling to the microcontroller that may control all functions related to using the projected capacitance touch screens and panels.

Apparatus for improving signal-to-noise performance of projected capacitance touch screens and panels

A force sensing touch sensor comprises a substrate having a plurality of conductive electrode rows and a plurality of conductive electrode columns substantially perpendicular to and over the plurality of conductive electrode rows on a surface of the substrate, and a force sensor at each corner of the substrate. When a touch is applied to the surface of the touch sensor, the capacitance value will change of a capacitor formed by an intersection of an electrode row and column proximate to the location of the touch to the surface of the touch sensor. These force sensors detect total and proportional force on the touch sensor substrate. This force information is then combined with the touch location(s) previously determined, and the individual touch force(s) can then be interpolated with sufficient resolution for three dimensional (3D) gesturing applications.

Projected capacitive touch detection with touch force detection using self-capacitance and mutual capacitance detection

A projected capacitive touch and force sensor capable of detecting multiple touches thereto and forces thereof is coupled with a digital device having multi-touch and force decoding capabilities. Once a touch has been established, a force thereof may be assigned to the touch based upon the magnitude of change of capacitance values determined during scans of the projected capacitive touch and force sensor. The touch forces applied to the touch sensor from the associated tracked touch points may be utilized in further determining three dimensional gesturing, e.g., X, Y and Z positions and forces, respectively.

Determining touch locations and forces thereto on a touch and force sensing surface

Systems and methods for determining multiple touch events in a multi-touch sensor system are provided. The system may have a touch sensor including nodes defined by a plurality of electrodes, which may comprise a first and second set. The method may include measuring self capacitance for at least two electrodes, detecting a touched electrode, and measuring the mutual capacitance for only a subset of the nodes (e.g., fewer than all of the nodes and including at least the nodes corresponding to the touched electrodes) resulting in the detection of two or more touched nodes. The self capacitance measurements may be performed on each of the electrodes, and the touched electrodes may comprise electrodes from both the first and second sets. Alternatively, the self capacitance measurements may be performed only on electrodes in the first set, and the touched electrodes may comprise electrodes from only the first set.

Capacitive touch system using both self and mutual capacitance

A touch sensor capable of detecting multiple touches thereto is coupled with a digital device having multi-touch decoding capabilities. These multi-touch decoding capabilities comprise touch data acquisition, touch identification, touch tracking and processed touch data output to a device associated with the touch sensor. Touch identification comprises touch location(s) peak detection, touch location(s) nudging and touch location(s) interpolation. Touch data acquisition locates potential touches on the touch sensor. Peak detection identifies where potential touch locations are on the touch sensor. Once a potential touch location(s) has been identified, touch location nudging examines each adjacent location thereto and interpolation examines the adjacent touch location values to generate a higher resolution location of the touch. Touch tracking compares time sequential 'frames' of touch identification data and then determines which touches are associated between frames for further processing, e.g., determining gesturing actions.

Method and system for multi-touch decoding

A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. A touch to the touch panel will cause a change of impedance of the transmission line at the location of the touch. Time domain reflectometry (TDR) is used for determining the location of the change of impedance of the transmission line by accurately measuring the return pulse time at the source of the initial pulse, and then converting the return pulse time to X-Y coordinates of the touch panel or screen.

Touch sense using time domain reflectometry

Systems and methods for determining multiple touch events in a multi-touch sensor system are provided. The system may include a capacitance measurement unit, a pulse drive unit, and a touch sensor having a plurality of nodes and a plurality of electrodes comprising at least two sets of electrodes. The method may include connecting a first electrode in a first set to the capacitance measurement unit, the pulse drive unit driving a voltage or current pulse onto a second electrode in a second set of electrodes. The method may further include the capacitance measurement unit measuring the mutual capacitance at a node corresponding to the first and second electrodes. The method may include comparing the measured mutual capacitance at the node with a previously measured mutual capacitance for the node, and reporting that the node has been touched if there has been a deviation from the previously measured mutual capacitance.

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Germantown, WI, United States of America

Jerry Hanauer