Input system for portable electronic device

A portable electronic device comprising:

• a touchscreen display;
• a battery;
• and
• an enclosure enclosing the touchscreen display and the battery, the enclosure comprising:
• a front cover positioned over the touchscreen display and defining a front exterior surface of the enclosure;
• and
• a housing component coupled to the front cover and defining an opening along a side exterior surface of the enclosure;
• and
• an input button system comprising:
• a beam structure at least partially within the enclosure and comprising:
• a first compliant segment positioned proximate a first end of the beam structure;
• and
• a second compliant segment positioned proximate a second end of the beam structure;
• a first strain sensing element coupled to the first compliant segment;
• a second strain sensing element coupled to the second compliant segment;
• a switch element positioned proximate a central region of the beam structure, the central region of the beam structure between the first end and the second end of the beam structure;
• and
• an input member positioned at least partially in the opening and configured to impart a force on the beam structure and on the switch element as a result of a force input applied to the input member;
• and
• a processing system configured to, in accordance with a determination that the force input satisfies a force threshold, cause the portable electronic device to perform an operation, the determination based at least in part on at least one of a first signal from the first strain sensing element or a second signal from the second strain sensing element, wherein the force threshold is less than an actuation force of the switch element.

An electronic device comprising:

• a housing component defining a side exterior surface;
• a front cover coupled to the housing component;
• a display positioned below the front cover;
• a haptic actuation system;
• an input member positioned along the side exterior surface of the housing component and configured to receive a force input;
• a beam structure at least partially within the electronic device, the beam structure configured to be deflected as a result of the force input on the input member;
• a first strain sensing element at a first location of the beam structure;
• a second strain sensing element at a second location of the beam structure;
• a processing system coupled to the first strain sensing element and the second strain sensing element and configured to:
• based at least in part on at least one of a first signal from the first strain sensing element or a second signal from the second strain sensing element, determine that the force input satisfies a first force threshold;
• and
• in response to determining that the force input satisfies the first force threshold, cause the haptic actuation system to produce a first tactile output;
• and
• a dome switch configured to collapse in response to the force input satisfying a second force threshold, thereby producing a second tactile output, the second force threshold greater than the first force threshold.