Stylus with external magnetic influence

1. An interface system comprising:

an electronic device comprising:

a housing; and

a cover coupled to the housing and defining an input surface;

a stylus comprising a magnetic component and configured to provide input to the electronic device via the input surface; and

a dock configured to be removably coupled to the electronic device and comprising:

a conductive coil configured to produce a magnetic field to impart a force on the magnetic component of the stylus; and

a magnetic shunt positioned under the conductive coil.

2. The interface system of claim 1 , wherein:

the electronic device comprises a display within the housing;

the dock further comprises circuitry configured to energize the conductive coil to produce the magnetic field;

the magnetic field extends through the housing, through the display, and through the input surface; and

the magnetic component is configured to interact with the magnetic field.

3. The interface system of claim 1 , wherein:

the dock comprises a group of conductive coils; and

the conductive coil is one of the group of conductive coils.

4. The interface system of claim 3 , wherein the conductive coils of the group of conductive coils are positioned in an overlapping arrangement.

5. A system for magnetically influencing an input device, comprising:

a computing device comprising:

an enclosure;

a touchscreen within the enclosure and configured to:

detect an input device at a first location on an exterior surface of the touchscreen; and

detect the input device at a second location on the exterior surface of the touchscreen, the second location different from the first location; and

an electromagnetic coil within the enclosure; wherein

the computing device is configured to:

produce a magnetic field above the exterior surface of the touchscreen, using the electromagnetic coil, in response to detecting the input device at the first location, thereby producing a tactile output via the input device; and

in response to detecting the input device at the second location, ceasing to produce the magnetic field.

6. The system of claim 5 , wherein:

the input device comprises:

a body; and

a magnetic component within the body; and

the electromagnetic coil is configured to produce the magnetic field around the magnetic component of the input device.

7. The system of claim 6 , wherein:

the electromagnetic coil is a first electromagnetic coil;

the magnetic field is a first magnetic field;

the magnetic component is a second electromagnetic coil; and

the input device further comprises:

a power source; and

circuitry configured to power the second electromagnetic coil to produce a second magnetic field.

8. The system of claim 6 , wherein the computing device further comprises control circuitry configured to control the electromagnetic coil in order to produce an alternating magnetic field.

9. The system of claim 6 , wherein the magnetic component is a permanent magnet.

10. The system of claim 6 , wherein the input device further comprises a spring movably supporting the magnetic component to the body.

11. The system of claim 10 , wherein the movably supported magnetic component has a resonant frequency between about 150 Hz and about 250 Hz.

12. A method, comprising:

detecting, at an electronic device with a touch sensor and a magnetic field source, a touch input from an input device having a magnetic component, the detecting comprising detecting the input device at a first location on an input surface of the electronic device;

in response to detecting the input device at the first location, producing a magnetic field with the magnetic field source, thereby imparting a force on the magnetic component of the input device;

detecting the input device at a second location on the input surface, the second location different from the first location; and

in response to detecting the input device at the second location, ceasing to produce the magnetic field.

13. The method of claim 12 , wherein:

detecting the input device at the first location on the input surface of the electronic device comprises detecting the input device outside of an input path along the input surface; and

detecting the input device at the second location on the input surface comprises detecting the input device within the input path.

14. The method of claim 13 , wherein:

the method further comprises determining a predicted input path based on at least one of a location and a direction of the touch input; and

the input path corresponds to the predicted input path.

15. The method of claim 12 wherein:

the method further comprises determining a target location of the input device on the input surface of the electronic device; and

producing the magnetic field comprises producing the magnetic field such that the force imparted on the magnetic component is in a direction of the target location.

16. The method of claim 15 , wherein:

the magnetic field source comprises a plurality of coils; and

producing the magnetic field comprises:

determining a combination of coils that will produce the magnetic field such that the force imparted on the magnetic component is in the direction of the target location; and

actuating the determined combination of coils.

17. The method of claim 12 , wherein:

detecting the input device at the first location on the input surface of the electronic device comprises detecting the input device within a threshold distance from a graphical object displayed by the electronic device; and

detecting the input device at the second location on the input surface comprises detecting the input device beyond the threshold distance from the graphical object displayed by the electronic device.

18. An interface system comprising:

an electronic device comprising:

a housing; and

a cover coupled to the housing and defining an input surface;

a stylus comprising a magnetic component and configured to provide input to the electronic device via the input surface; and

a dock configured to be removably coupled to the electronic device and comprising:

a frame defining a recess; and

a coil positioned in the frame and configured to produce a magnetic field to impart a force on the magnetic component of the stylus, wherein

the electronic device is configured to be received in the recess and at least partially surrounded by the frame.

19. The interface system of claim 18 , wherein:

the coil is a first coil; and

the dock further comprises a plurality of additional coils positioned in the frame.

20. The interface system of claim 18 , wherein:

the coil defines a plurality of turns wrapped about a coil axis; and

the coil axis is perpendicular to the input surface of the electronic device when the electronic device is received in the recess.

21. The interface system of claim 18 , wherein the force imparted on the magnetic component of the stylus vibrates the stylus.