COMPENSATION FOR CAPACITANCE CHANGE IN TOUCH SENSING DEVICE

摘要

This relates to compensation for undesirable capacitance changes in a touch sensing device, where the capacitance changes are not indicative of a touch at the device. The touch sensing device can include a touch sensor panel having touch sensors for sensing a touch at the panel, a flexible circuit for transmitting the sensed touch signal from the panel, and a touch controller for receiving and processing the transmitted signal. To compensate for the capacitance changes, the touch sensing device can include one or more reference conductive traces decoupled from touch sensors of the device to measure non-touch capacitances in the device. The touch sensing device can then adjust a touch signal from the touch sensors using the non- touch capacitance measurements to substantially reduce or eliminate the non-touch capacitances from the signal.