Force-sensing pointing device

摘要

A thermally stable, mass-producible pointing device (10) producing an analog signal proportional to an applied force comprises actuator (20), including an arm (22) and a force transfer member (26), a connector (44), and a sensor (50). The connector maintains the force transfer member in contact with the sensor yet allows the force transfer member to change dimensions with ambient temperature without inducing stresses detectable by the sensor. In a preferred embodiment, the connector comprises an elastomeric adhesive and the sensor comprises a force-sensing resistor. The force transfer member is prevented from coming out of the assembly either by a retainer (12) comprising a shell or a potting compound retaining the force transfer member but permitting thermal expansion or contraction of the force transfer member. The force transfer member typically has a rounded or bevelled bottom surface (28) so the actuator rocks under an applied force. The area of the bottom surface of the force transfer member transferring the force changes as the actuator rocks, and the force is transferred to the sensor at a single contiguous area whose position changes in response to a change in force.