Capacitive pointing stick apparatus with floating conductive cone for symbol manipulation in a graphical user interface

A structure is provided for a user-manipulable input device, such as an in-keyboard, joystick-type device, for allowing a user to provide input to a computer graphical user interface (GUI). The structure includes a user-manipulable, articulating member, and a plurality of stationary, electrically conductive sensors. The articulating member also has an electrically conductive member. The physical disposition of the articulating member and the sensors provides narrow gaps, across which are measurable capacitances. As the user manipulates the articulating member, the capacitances change in value. Circuitry produces signals related to the capacitances, and the signals are processed, according to a transfer function, to generate GUI input signals. The sensors are preferably sensing electrodes, incorporated into a circuit board. The articulating member is preferably a cone-shaped member, having a conductive surface which faces the sensors. The articulating member is mechanically coupled to the board holding the sensors by a flexing member that biases the articulating member to a quiescent position.