Resolving touch and press for multiple input objects

1. A processing system for an input device, comprising:

sensor circuitry configured to receive resulting signals from a plurality of force sensors of the input device; and

processing circuitry configured to:

determine a first position of a first input object and a second position of a second input object on a surface of the input device;

determine a plurality of force values based on the resulting signals;

partition the surface into a plurality of regions comprising a first region and a second region;

calculate a first aggregate force metric for the first region based on a first subset of the plurality of force values;

determine that the first region comprises an input force based on a first comparison comprising the first aggregate force metric;

calculate a first distance between the first position and the first region and a second distance between the second position and the first region; and

determine that the first input object is applying more force to the surface than the second input object in response to the first distance being smaller than the second distance.

2. The processing system of claim 1 , wherein calculating the first aggregate force metric comprises:

selecting a first force sensor in the first region comprising a first force value;

identifying a second force sensor in the second region of the surface that mirrors the position of the first force sensor and comprises a second force value; and

calculating a ratio of the first force value to the second force value,

wherein the first aggregate force metric comprises a summation of ratios,

wherein the first comparison is between the first aggregate force metric and a tuned parameter, and

wherein the first aggregate force metric exceeds the tuned parameter.

3. The processing system of claim 2 , wherein the determination module also applies a ceiling function to the ratio before executing the summation.

4. The processing system of claim 2 , wherein the first region is a left half of the surface, and wherein the second region is a right half of the surface.

5. The processing system of claim 1 , wherein the processing circuitry is further configured to:

apply a first plurality of weights to the first subset of the plurality of force values before calculating the first aggregate force metric to compensate for positional bending and tilt;

apply a second plurality of weights to a second subset of the plurality of force values to compensate for positional bending and tilt; and

calculate a second aggregate force metric for the second region of the surface by summing the second subset of the plurality of force values,

wherein the first comparison is between the first aggregate force metric and a product of a tuned parameter and the second aggregate force metric,

wherein the first aggregate force metric exceeds the product.

6. The processing system of claim 5 , wherein the first region is a top half of the surface, and wherein the second region is a bottom half of the surface.

7. The processing system of claim 5 , wherein the processing circuitry is further configured to partition the surface into the first region and the second region based on the first position and the second positions, wherein the first region comprises the first position and the second region comprises the second position.

8. The processing system of claim 5 , wherein the processing circuitry is further configured to:

execute a second comparison comprising the first aggregate force metric and a press threshold,

wherein the first aggregate force metric exceeds the press threshold, and

wherein determining that the first region comprises the input force is further based on the second comparison.

9. A method for operating a processing system for an input device comprising a surface, comprising:

determining a first position of a first input object and a second position of a second input object on the surface;

receiving a plurality of resulting signals from a plurality of force sensors;

determining a plurality of force values for the plurality of force sensors based on the plurality of resulting signals;

partitioning the surface into a plurality of regions comprising a first region and a second region;

calculating a first aggregate force metric for the first region of the surface based on a first subset of the plurality of force values;

determining that the first region comprises an input force based on a first comparison comprising the first aggregate force metric;

calculating a first distance between the first position and the first region and a second distance between the second position and the first region; and

determining that the first input object is applying more force to the surface than the second input object in response to the first distance being smaller than the second distance.

10. The method of claim 9 , wherein calculating the first aggregate force metric comprises:

selecting a first force sensor in the first region comprising a first force value;

identifying a second force sensor in the second region of the surface that mirrors the position of the first force sensor and comprises a second force value; and

calculating a ratio of the first force value to the second force value,

wherein the first aggregate force metric comprises a summation of ratios,

wherein the first comparison is between the first aggregate force metric and a tuned parameter, and

wherein the first aggregate force metric exceeds the tuned parameter.

11. The method of claim 9 , further comprising:

applying a first plurality of weights to the first subset of the plurality of force values before calculating the first aggregate force metric to compensate for positional bending and tilt;

applying a second plurality of weights to a second subset of the plurality of force values to compensate for positional bending and tilt; and

calculating a second aggregate force metric for the second region of the surface by summing the second subset of the plurality of force values,

wherein the first comparison is between the first aggregate force metric and a product of a tuned parameter and the second aggregate force metric, and

wherein the first aggregate force metric exceeds the product.

12. The method of claim 11 , further comprising:

executing a second comparison comprising the first aggregate force metric and a press threshold,

wherein the first aggregate force metric exceeds the press threshold, and

wherein determining the first region comprises the input force is further based on the second comparison.

13. The method of claim 12 , further comprising:

partitioning the surface into the first region and the second region based on the first position and the second position,

wherein the first region comprises the first position, and

wherein the second region comprises the second position.

14. The method of claim 9 , further comprising:

executing, by a software application, an action in response to determining that the first input object is applying more force to the surface than the second input object.

15. An input device, comprising:

a surface;

a plurality of force sensors below the surface; and

a processing system that:

determines a first position of a first input object and a second position of a second input object on the surface;

receives a plurality of resulting signals from the plurality of force sensors;

determines a plurality of force values for the plurality of force sensors based on the plurality of resulting signals;

partitions the surface into a plurality of regions comprising a first region and a second region;

calculates a first aggregate force metric for a first region of the surface based on a first subset of the plurality of force values;

determines the first region comprises an input force based on a first comparison comprising the first aggregate force metric;

calculates a first distance between the first position and the first region and a second distance between the second position and the first region; and

determines that the first input object is applying more force to the surface than the second input object in response to the first distance being smaller than the second distance.

16. The input device of claim 15 , wherein calculating the first aggregate force metric comprises:

selecting a first force sensor in the first region comprising a first force value;

identifying a second force sensor in the second region of the surface that mirrors the position of the first force sensor and comprises a second force value; and

calculating a ratio of the first force value to the second force value,

wherein the first aggregate force metric comprises a summation of ratios,

wherein the first comparison is between the first aggregate force metric and a tuned parameter, and

wherein the first aggregate force metric exceeds the tuned parameter.

17. The input device of claim 15 , wherein the processing system also:

applies a first plurality of weights to the first subset of the plurality of force values before calculating the first aggregate force metric to compensate for positional bending and tilt;

applies a second plurality of weights to a second subset of the plurality of force values to compensate for positional bending and tilt; and

calculates a second aggregate force metric for the second region of the surface by summing the second subset of the plurality of force values,

wherein the first comparison is between the first aggregate force metric and a product of a tuned parameter and the second aggregate force metric, and

wherein the first aggregate force metric exceeds the product.

18. The input device of claim 15 , wherein the processing system also:

partitions the surface into the first region and the second region based on the first position and the second position, wherein the first region comprises the first position and the second region comprises the second position;

executes a second comparison comprising the first aggregate force metric and a press threshold,

wherein the first aggregate force metric exceeds the press threshold, and

wherein determining the first region comprises the input force is further based on the second comparison.

19. The input device of claim 15 , wherein at least one of the plurality of force sensors comprises:

a first electrode driven as a transmitter; and

a second electrode driven as a receiver and separated from the first electrode by a spacing,

wherein at least one selected from a group consisting of the first electrode and the second electrode deflects in response to the force and reduces the spacing, and

the resulting signal for the force sensor reflects transcapacitance.

20. The input device of claim 15 , wherein at least one of the plurality of force sensors comprises:

a first electrode driven as an absolute capacitance sensor; and

a second electrode driven with a reference voltage and separated from the first electrode by a spacing,

wherein at least one selected from a group consisting of the first electrode and the second electrode deflects in response to the force and reduces the spacing, and

the resulting signal for the force sensor reflects absolute capacitance.