Method and Apparatus for Ghosting Suppression in Capacitive Key Matrix and Touch Pads

摘要

An apparatus includes a plurality of capacitive sensors arranged in a matrix on a substrate. A measuring circuitry measures the capacitance of each of a plurality of row lines and a plurality of column lines in the matrix coupled to the capacitive sensors. A first electrode is on the substrate on a first edge of the matrix and is proximal to a first corner of the matrix. The first electrode is coupled to the measuring circuitry. A second electrode is on the substrate on the first edge of the matrix and is proximal to a second corner of the matrix, the second corner opposing the first corner on the first edge. The second electrode is coupled to the measuring circuitry. The measuring circuitry determines the positions of two touches to the touch pad. Methods are disclosed.

主权项

1. A capacitive touch pad, comprising:
a plurality of capacitive sensors arranged in a matrix on a substrate; measuring circuitry configured to measure a capacitance of each of a plurality of row lines and a plurality of column lines in the matrix coupled to the capacitive sensors; a first electrode on the substrate on a first edge of the matrix and proximal to a first corner of the matrix, the first electrode coupled to the measuring circuitry; and a second electrode on the substrate on the first edge of the matrix and proximal to a second corner of the matrix, the second corner opposing the first corner on the first edge, the second electrode coupled to the measuring circuitry.