Tethered stylyus for use with a capacitance-sensitive touchpad

摘要

A tethered pen is coupled to an unused sense line input of touchpad sensor circuitry of a capacitance-sensitive touchpad, wherein the capacitance-sensitive touchpad is operable in a normal manner for detecting touch or proximity of a finger or other conductive pointing object to a touchpad surface by receiving input at a first sense input from a first sense line embedded within the touchpad, and wherein a second sense input is coupled to a tethered pen via a second sense line, wherein the second sense line enables the touchpad sensor circuitry to detect the touch of the pen on or in proximity to electrodes within the touchpad.