Compensation for air gap in an input device

A display device integrated with a capacitive sensing device comprising:

• a plurality of common electrodes;
• a plurality of receiver electrodes;
• a processing system coupled to the plurality of common electrodes and the plurality of receiver electrodes, the processing system configured to:
• drive the plurality of common electrodes for display updating and capacitive sensing;
• receive resulting signals with the receiver electrodes when the plurality of common electrodes are driven for capacitive sensing;
• determine a first capacitive image based on the resulting signals;
• compare the first capacitive image to a baseline capacitive image to determine a delta capacitive image;
• compare the delta capacitive image to one or more saturation capacitance values;
• in response to the comparison, replace the one or more saturation capacitance values with one or more capacitance values from the delta capacitive image;
• and
• determine one or more calibration values based on the one or more saturation capacitance values;
• and
• a cover lens disposed over the plurality of common electrodes, wherein the one or more calibration values calibrate for an air gap defined between the cover lens and the plurality of common electrodes.

A method of capacitive sensing with a display device integrated with a capacitive sensing device having a plurality of common electrodes and a plurality of receiver electrodes, the method comprising:

• driving the plurality of common electrodes for display updating and capacitive sensing;
• receiving resulting signals from the receiver electrodes when the plurality of common electrodes are driven for capacitive sensing;
• determining a first capacitive image based on the resulting signals;
• comparing the first capacitive image to a baseline capacitive image to determine a delta capacitive image;
• comparing the delta capacitive image to one or more saturation capacitance values;
• in response to the comparing, replacing the one or more saturation capacitance values with one or more capacitance values from the delta capacitive image;
• and
• determining one or more calibration values based on the one or more saturation capacitance values,
• wherein the one or more calibration values calibrate for an air gap defined between a cover lens of a display device integrated with a capacitive sensing device and the plurality of common electrodes.