System and methods for determining object information using selectively floated electrodes

A sensor device comprising:

• an input surface;
• a plurality of transmitter electrodes and a plurality of receiver electrodes proximate to the input surface, the plurality of transmitter electrodes and the plurality of receiver electrodes configured to capacitively sense objects in a sensing region;
• a shield layer comprising at least one shield electrode, the at least one shield electrode disposed proximate the plurality of transmitter electrodes and the plurality of receiver electrodes;
• a display disposed proximate the shield layer, wherein the plurality of transmitter electrodes, the receiver electrodes, and the shield layer are configured to deflect toward the display in response to force applied by an input object to the input surface;
• and
• a processing system coupled to the plurality of transmitter electrodes, the plurality of receiver electrodes, and the at least one shield electrode, the processing system configured to:
• selectively operate in a first mode, wherein when operating in the first mode the processing system electrically drives the at least one shield electrode to an electrical potential while driving the plurality of transmitter electrodes and receiving first type resulting signals using the plurality of receiver electrodes;
• selectively operate in a second mode, wherein when operating in the second mode the processing system electrically floats the at least one shield electrode while driving the plurality of transmitter electrodes, and receiving second type resulting signal using the plurality of receiver electrodes;
• determine positional information for objects in the sensing region using at least the first type resulting signals;
• and
• determine force information for objects in the sensing region using at least the second type resulting signals.

A processing system for a capacitive input device comprising:

• a sensor module comprising sensor circuitry, the sensor module configured to:
• selectively operate in a first mode and a second mode;
• wherein:
• while operating in the first mode, the sensor module is configured to drive a plurality of sensing electrodes configured to sense objects in a sensing region while driving a shield layer to generate resulting signals of a first type indicative of objects in the sensing region;
• while operating in the second mode, the sensor module is configured to drive the plurality of sensing electrodes configured to sense objects in the sensing region while floating the shield layer to generate resulting signals of a second type indicative of objects in the sensing region;
• a determination module configured to:
• determine positional information for objects in the sensing region using at least one of the resulting signals of the first type and the resulting signals of the second type;
• and
• determine force information for objects in the sensing region using at least the resulting signals of the second type.

A method for determining input information in a sensing region of a capacitive input device comprising:

• driving a plurality of sensing electrodes configured to sense objects in the sensing region while driving a shield layer to generate resulting signals of a first type indicative of objects in the sensing region;
• driving the plurality of sensing electrodes configured to sense objects in the sensing region while floating the shield layer to generate resulting signals of a second type indicative of objects in the sensing region;
• determining positional information for objects in the sensing region using at least one of the resulting signals of the first type and the resulting signals of the second type;
• and
• determining force information for objects in the sensing region using at least the resulting signals of the second type.