Apple Inc.
Load Cell Array for Detection of Force Input to an Electronic Device Enclosure

Abstract:

A force input sensor includes a load cell to adapt a compressive force applied to the force input sensor into a strain experienced by a strain sensor in the load cell. In particular, the load cell includes two compression plates separated from one another by a gap so as to define a volume between them. A flexible substrate (a "diaphragm")--includes a strain sensor and is disposed and supported within the volume. One of the two compression plates includes a feature (a "loading feature") that extends toward a central region of the flexible substrate. As a result of this construction, when the compression plates receive a compressive force, the loading feature induces a bending moment in the flexible substrate, thereby straining the strain sensor.