Synaptics Incorporated
Force sensing input device utilizing strain gauges

Abstract:

A force sensing device includes a first force sensor and a second force sensor. The first force sensor is configured to output a first force resulting signal and includes a first strain gauge coupled to a first voltage source and a first trace. The first force sensor further includes a second strain gauge coupled to a second voltage source and the first trace. The second force sensor is configured to output a second force resulting signal having a polarity opposite that of the first force resulting signal. The second force sensor includes a first strain gauge coupled to the second voltage source and a second trace, and a second strain gauge coupled to the first voltage source and the second trace.