US Patent 7977587 Two-stage switch assembly

A switch assembly is provided to actuate a pair of switches using a single push key, e.g. for a camera that utilizes a first switch to activate an image focusing function and a second switch to activate a camera shutter. The switch assembly comprises a contact pad switch and a dome switch that are located laterally to one another. When the push key receives a first downward force, only the contact pad switch becomes activated and a first electric circuit is completed. When the push key receives a second downward force that is greater than the first force, the dome switch collapses and a second electric circuit is completed.