Touchnetix Limited

Touchnext Limited

Christopher Kyle Ard

Stephen William Roberts

Peter Timothy Sleeman

A capacitive sensor comprising: a first electrode; a displacement element moveably mounted relative to the first electrode; and a second electrode coupled to the displacement element so that displacement of the displacement element along a displacement direction changes a separation between the first electrode and the second electrode; and a controller element configured to selectively operate in a displacement sensing mode and in a proximity sensing mode, wherein in the displacement sensing mode, the controller element is configured to electrically couple the second electrode to a reference potential and to electrically couple the first electrode to capacitance measurement circuitry to measure a capacitance characteristic of the first electrode to determine a displacement of the displacement element relative to the reference electrode; and in the proximity sensing mode, the controller element is configured to electrically couple the second electrode to capacitance measurement circuitry to measure a capacitance characteristic associated with the second electrode to detect the presence of an object in proximity to the second electrode; and in the displacement sensing mode, the controller element is configured to electrically couple the second electrode to a reference potential signal.

Capacitive sensing apparatus and methods

A touch-sensitive position sensor is disclosed. The sensor comprises an array of first electrodes and an array of second electrodes arranged to cross one another in a pattern to define a sensing surface. The sensing surface has a rectangular shape which is formed into a cylinder such that first and second opposing edges of the sensing surface are adjacent one another. A controller is coupled to respective ones of the first electrodes and the second electrodes and arranged to measure changes in an electrical parameter, e.g. capacitance or resistance, associated with the first and second electrodes caused by the presence of the object adjacent the sensing surface. The controller is further operable to determine a reported position for the object from these measurements in a coordinate system defined relative to the electrodes. At least some of the electrodes are arranged to follow paths which are non-linear within the sensing surface such that object positions along a straight line between the first and second opposing edges on the sensing surface correspond with reported positions along a closed curve in the coordinate system defined relative to the electrodes. Thus, a continuous movement around a circumference of the cylindrical sensing surface is reported as a continuous movement around a closed path in the coordinate system defined relative to the electrodes.

Touch sensors and touch sensing methods

A touch-sensitive position sensor is disclosed. The sensor comprises an array of first electrodes and an array of second electrodes arranged in a pattern to provide a sensing surface, wherein at least some of the first electrodes and the second electrodes are arranged to follow paths which are non-linear within the sensing surface such that there are ends of the first electrodes and ends of the second electrodes which meet a common edge of the sensing surface. A controller is coupled to respective ones of the first electrodes and the second electrodes and arranged to determine a reported position for an object adjacent the sensing surface by measuring changes in an electrical parameter e.g. capacitance or resistance, associated with the first electrodes and the second electrodes which is caused by the presence of the object. The controller is further operable to provide an indication of the reported position in a first coordinate system defined relative to the first electrodes and the second electrodes, the sensor further comprises a processor arranged to receive the indication of reported position from the controller in the first coordinate system and to transform the reported position to an output position in a second coordinate system, wherein the transform is based on the non-linear pattern of electrodes. Thus, a sensor having electrodes which are distorted so as to meet a common edge may be provided for ease of connectability, with the distortion been accounted for through the transform performed by the processor.

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Chandlers Ford, United Kingdom

Christopher Kyle Ard