A force feedback mouse interface device connected to a host computer and
providing realistic force feedback to a user. The mouse interface device
includes a mouse object and a linkage coupled to the mouse that includes
a plurality of members rotatably coupled to each other in a planar
closed-loop linkage, two of the members coupled to ground and rotatable
about the same axis. Two actuators, preferably electromagnetic voice
coils, provide forces in the two degrees of freedom of the planar
workspace of the mouse object. Each of the actuators includes a moveable
coil portion integrated with one of the members of the linkage and a
magnet portion coupled to the ground surface through which the coil
portion moves. At least one sensor is coupled to the ground surface that
detects movement of the linkage and provides a sensor signal including
information from which a position of the mouse object in the planar
workspace can be determined.