US Patent 9444454 Dynamically reconfigurable capacitive sensor array

In a keyboard of the type including a key cap and a capacitive sensor disposed underneath the key cap, a method including operating the capacitive sensor in a first mode configured for near field detection and generating a first variable capacitance, and operating the capacitive sensor in a second mode configured for far field detection and generating a second variable capacitance. The method further includes determining key motion based on the first variable capacitance and determining finger presence based on the second variable capacitance.