US Patent 7591195 Optical torque sensor

A torque sensor that includes a sensor housing, a sensor input member at least partially received in the sensor housing, a sensor output member at least partially received in the sensor housing, a torsionally resilient coupling member that couples the sensor input member to the sensor output member and an optical sensor system that includes a light source, one or more encoders and one or more optical sensors. The encoder or encoders periodically transmit light between the light source and the at least one optical sensor based on an amount of relative rotation between the sensor input member and the sensor output member.