Patent ID: 6411193
Filing Date: 2002-06-25
Classification: H01C

Abstract:
A pointing stick comprising;a substrate; an input pillar set vertically on the substrate; and at least one strain gauge, a portion of the strain gauge set between the input pillar and the substrate, the strain gauge comprising: a first pressure resistor set on the substrate, the first pressure resistor having the shape of a flat strip, the first pressure resistor distorting under a pressure applied along a longitudinal axis of the input pillar, the distortion changing the resistance of the first pressure resistor according to the pressure; a first electrode and a second electrode electrically connected to the first pressure resistor, a bottom side of the first pressure resistor contacting the first electrode, a top side of the first pressure resistor contacting the second electrode, the first electrode and the second electrode forming a loop to let current pass through the first pressure resistor, the first electrode and the second electrode being separated by a gap with a predetermined distance in a pressing direction, the pressing direction parallel to the longitudinal axis of the input pillar; wherein by applying a force on the input pillar, the pressure is produced along the pressing direction on the first pressure resistor, the pressure distorting both the top side and the bottom side of the first pressure resistor along the pressing direction, and the strain gauge produces pointing signals that correspond to the pressure.