Mitigating an influence of external magnetic fields on an analog computer peripheral device

1 . A computer mouse comprising:

a keyplate;

a first conductive element coupled to the keyplate;

a second conductive element coupled to the keyplate;

a first sensor element configured to detect a first magnetic field generated by the first conductive element and generate corresponding first sensor data;

a second sensor element configured to detect a second magnetic field generated by the second conductive element and generate corresponding second sensor data; and

one or more processors configured to:

determine a position of the keyplate based on the first or second sensor data; and

mitigate interference caused by an external magnetic field via common mode rejection based on a difference value of the first sensor data and the second sensor data.

2 . The computer mouse of claim 1 wherein the first sensor element is an inductive coil configured to:

induce electrical eddy currents in the first conductive element;

detect a resulting first magnetic field; and

generate the first sensor data based on the detected resulting first magnetic field, and

wherein the second sensor element is an inductive coil configured to:

induce electrical eddy currents in the second conductive element;

detect a resulting second magnetic field; and

generate the second sensor data based on the detected resulting second magnetic field.

3 . The computer mouse of claim 1 wherein the first sensor element is an inductive coil wound in a clockwise direction, and the second sensor element is an inductive coil wound in a counter-clockwise direction.

4 . The computer mouse of claim 3 wherein the first magnetic field is of a first polarity, and the second magnetic field is of a second polarity opposite the first polarity.

5 . The computer mouse of claim 1 wherein the first conductive element and the second conductive element are electrically coupled together.

6 . The computer mouse of claim 5 wherein the first and second conductive elements are physically coupled together as a monolithic structure.

7 . The computer mouse of claim 1 wherein the first sensor element and the second sensor element are comprised of a single, common conductive element connected in series.

8 . The computer mouse of claim 1 wherein the difference value of first sensor data and second sensor data when influenced by the external magnetic field is lesser in amplitude than the influence of the external magnetic field on either the first sensor data or second sensor data.

9 . A method of operating a computer mouse, the method comprising:

driving an electrical current through a first sensor element and a second sensor element;

generating a first magnetic field by the first sensor element in response to being driven by the electrical current;

generating a second magnetic field by the second sensor element in response to being driven by the electrical current;

inducing first electrical eddy currents in a first conductive element coupled to a keyplate of the computer mouse, the induced first electrical eddy currents caused by the first magnetic field;

inducing second electrical eddy currents in a second conductive element coupled to a keyplate of the computer mouse, the induced second electrical eddy currents caused by the second magnetic field;

generating a third magnetic field by the first conductive element in response to the first electrical eddy currents;

generating a fourth magnetic field by the second conductive element in response to the second electrical eddy currents;

detecting the third magnetic field by the first sensor element and generating corresponding first sensor data;

detecting the fourth magnetic field by the second sensor element and generating corresponding second sensor data;

determining a position of the keyplate based on the first or second sensor data; and

reducing interference caused by an external magnetic field via common mode rejection based on a difference value of the first sensor data and the second sensor data.

10 . The method of claim 9 wherein the first sensor element is an inductive coil wound in a clockwise direction, and the second sensor element is an inductive coil wound in a counter-clockwise direction.

11 . The method of claim 9 wherein the first magnetic field is of a first polarity, and the second magnetic field is of a second polarity opposite the first polarity.

12 . The method of claim 9 wherein the first conductive element and the second conductive element are electrically coupled together.

13 . The method of claim 9 wherein the first and second conductive elements are physically coupled together as a monolithic structure.

14 . The method of claim 9 wherein the first sensor element and the second sensor element are comprised of a single, common conductive element connected in series.

15 . An input device comprising:

a button;

a conductive element coupled to the button;

a substrate;

a single conductor coupled to the substrate, the single conductor configured into:

a first coil; and

a second coil configured adjacent to and in series with the first coil;

a first sensor element configured to detect a first magnetic field generated by the conductive element and generate corresponding first sensor data;

a second sensor element configured to detect a second magnetic field generated by the conductive element and generate corresponding second sensor data; and

one or more processors configured to:

determine a position of the button based on the first or second sensor data; and

mitigate interference caused by an external magnetic field via common mode rejection based on a difference value of the first sensor data and the second sensor data.

16 . The input device of claim 15 wherein the first coil is configured to:

induce electrical eddy currents in the conductive element;

detect a resulting first magnetic field from the conductive element; and

generate the first sensor data based on the detected resulting first magnetic field, and

wherein the second coil is configured to:

induce electrical eddy currents in the conductive element;

detect a resulting second magnetic field from the conductive element; and

generate the second sensor data based on the detected resulting second magnetic field.

17 . The input device of claim 15 wherein the first coil is wound in a clockwise direction, and wherein the second coil is wound in a counter-clockwise direction.

18 . The input device of claim 15 wherein the first magnetic field is of a first polarity, and the second magnetic field is of a second polarity opposite the first polarity.

19 . The input device of claim 15 wherein the input device is a computer mouse.

20 . The input device of claim 15 wherein the button is a keyplate.