AN ELECTRONIC STYLUS WITH A FORCE RE-DIRECTING COUPLING

摘要

A force sensor assembly particularly suited for use in an electronic stylus that senses the contact force on its nib for recording pen strokes and handwriting recognition. The sensor assembly has a housing in which force sensing circuitry is mounted. The force sensing circuitry is configured for receiving an input force to be sensed and converting the input force into an output signal indicative of the input force. A coupling transmits the input force to the force sensing circuitry. The coupling has an inner section that applies the input force to the load bearing member, an outer section that receives the contact force on the nib and a collapsible section that allows the outer section to move relative to the inner section when the contact force exceeds a threshold. The relative movement of the outer section is limited by an abutment on the housing so that the input force on the force sensing circuitry never exceeds the threshold. This protects the force sensing circuitry from damage by sharp impact loads such as dropping the stylus on its nib.