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: A capacitive position sensor for determining the position of an object along first and second directions is described. The sensor comprises a substrate having an arrangement of electrodes mounted on a single surface thereof. The electrodes are arranged so as to define an array of sensing cells arranged in columns and rows to form a sensing area. Each of the sensing cell including a column sensing electrode and a row sensing electrode with the column sensing electrodes of sensing cells in the same column being electrically coupled together and the row sensing electrodes of sensing cells in the same row also being electrically coupled together.

Abstract: Keyboards, keypads and other data entry devices can suffer from a keying ambiguity problem. In a small keyboard, for example, a user's finger is likely to overlap from a desired key to onto adjacent ones. An iterative method of removing keying ambiguity from a keyboard comprising an array of capacitive keys involves measuring a signal strength associated with each key in the array, comparing the measured signal strengths to find a maximum, determining that the key having the maximum signal strength is the unique user-selected key, and maintaining that selection until either the initially selected key's signal strength drops below some threshold level or a second key's signal strength exceeds the first key's signal strength.