Force-detecting input structure
An input mechanism, such as a crown, detects amounts of applied force. In various examples, an assembly including an input mechanism has an enclosure; a stem coupled to the enclosure such that the stem is rotatable, translatable, and transversely moveable with respect to the enclosure; a sensor, coupled between the stem and the housing, to which force is transferred when the stem moves with respect to the housing; and a processing unit coupled to the sensor. The processing unit is operable to determine a measurement of the force, based on a signal from the sensor.
1. An electronic watch comprising:
a housing defining an opening;
a touch display positioned at least partially within the opening of the housing;
a crown positioned along a side of the housing and comprising:
a cap that is configured to receive a force input; and
a force sensor coupled to the cap and comprising a first conductive element and a second conductive element that is separated from the first conductive element; and
a processing unit positioned within the housing and operably coupled to the force sensor, the processing unit configured to estimate an amount of the force input based on a change in capacitance between the first conductive element and the second conductive element.
2. The electronic watch of claim 1 , wherein:
the crown further comprises a stem coupled to the cap;
the opening is a first opening;
the housing defines a second opening along the side of the housing; and
the stem of the crown extends into the second opening and is rotatably coupled to the housing.
3. The electronic watch of claim 2 , wherein:
the force sensor is positioned between the stem and the cap of the crown;
the force input causes the cap to move with respect to the stem; and
the movement of the cap causes the change in capacitance between the first conductive element and the second conductive element.
4. The electronic watch of claim 2 , wherein:
the force sensor is positioned along an end of the stem;
the force input causes the cap and the stem to move with respect to the housing; and
the movement of the cap and the stem causes the change in capacitance between the first conductive element and the second conductive element.
5. The electronic watch of claim 4 , wherein:
the electronic watch further comprises a dome switch positioned along the end of the stem; and
the force sensor is positioned between the dome switch and the stem.
6. The electronic watch of claim 1 , wherein:
the first conductive element is separated from the second conductive element by a compliant material; and
the force input causes the compliant material to deform moving the first conductive element closer to the second conductive element.
7. The electronic watch of claim 6 , wherein the compliant material is a silicone material.
8. An electronic watch comprising:
a housing;
a display positioned at least partially within the housing;
a crown rotatably coupled to the housing and configured to receive a rotational input, the crown comprising a force sensor that is configured to deform in response to a force applied to the crown; and
a processing unit disposed within the housing, operably coupled to the force sensor, and configured to estimate an amount of the force in response to an output of the force sensor; wherein:
the display is responsive to the amount of the force estimated by the processing unit; and
the display is responsive to the rotational input received by the crown.
9. The electronic watch of claim 8 , wherein:
the force sensor comprises a first conductive element and a second conductive element;
a compliant material is positioned between the first conductive element and the second conductive element; and
the compliant material is configured to deform in response to the force applied to the crown.
10. The electronic watch of claim 9 , wherein:
the electronic watch further comprises an inner core coupled to the housing;
the crown comprises a cap that is coupled to the inner core;
the first conductive element is fixed with respect to the inner core; and
the second conductive element is fixed with respect to the cap.
11. The electronic watch of claim 8 , wherein:
the crown comprises a cap that is configured to receive the force; and
the force displaces the cap toward the housing.
12. The electronic watch of claim 8 , wherein:
the force is a first force;
the crown comprises a cap that is configured to receive the first force;
the cap is configured to displace in a first direction that is toward the housing in response to receiving the first force;
the cap is configured to receive a second force;
the cap is configured to displace in a second direction that is transverse to the first direction in response to the second force; and
the display is responsive to the second force applied to the crown.
13. The electronic watch of claim 8 , wherein:
the display is configured to display an icon;
the processing unit is configured to determine if the amount of the force exceeds a threshold; and
an application associated with the icon is executed in response to the force exceeding the threshold.
14. An electronic watch, comprising:
a housing;
a display positioned at least partially within the housing and configured to display a graphical output;
a crown coupled to the housing and comprising:
a cap defining an external surface that is configured to receive a force; and
a force sensor that is coupled to the cap and configured to produce a non-binary output in response to the received force; and
a processing unit configured to modify the graphical output of the display in response to the non-binary output.
15. The electronic watch of claim 14 , wherein:
the force sensor comprises a first conductive element and a second conductive element;
the first conductive element is separated from the second conductive element by a compliant dielectric material; and
the force sensor is configured to produce the non-binary output based on a change in capacitance between the first conductive element and the second conductive element caused by the received force.
16. The electronic watch of claim 15 , wherein:
the crown comprises a stem coupled to the cap;
the first conductive element is fixed with respect to the cap; and
the second conductive element is fixed with respect to the stem.
17. The electronic watch of claim 14 , wherein the processing unit is configured to determine if the non-binary output exceeds a threshold.
18. The electronic watch of claim 17 , wherein the electronic watch is configured to execute an application in response to the non-binary output exceeding the threshold.
19. The electronic watch of claim 14 , wherein:
the force sensor comprises a strain gauge; and
the strain gauge is configured to produce the non-binary output in response to the received force.
20. The electronic watch of claim 14 , wherein:
the force sensor comprises a piezoelectric element; and
the piezoelectric element is configured to produce the non-binary output in response to the received force.