Abstract: A stylus for a capacitive touch screen includes an inverting charge integrator circuit is connected to a conductive tip for providing an output signal proportional to a charge induced at the conductive tip. An inverting amplifier generates an amplified signal proportional to the signal output from the inverting charge integrator. A conductive contact provides electrical or capacitive coupling between the amplified signal and an exterior of the stylus which may provide electrical or capacitive coupling with a person holding the stylus. In other embodiments, the order of the inverting charge integrator and the inverting amplifier may be reversed. A power supply circuit powers the inverting charge integrator and the inverting amplifier. Shielding may be implemented to isolate the stylus circuitry and prevent oscillation. The provided circuitry may enable a ball point or other fine point stylus tip configurations.

Abstract: An electronic stylus to be used with a capacitive touch screen includes a tip portion having an electrically conductive tip and an electrically conductive supporting rod attached to the tip. The tip portion further includes a first electrical shielding tube enclosing and shielding the supporting rod and a second electrical shielding tube enclosing the first electrical shielding tube and the supporting rod. The electrical stylus further includes a circuit coupled to the supporting rod to integrate and amplify a current induced at the tip and an electrical conductive housing to house the circuit therein. The first electrical shielding tube and the second electrical shielding tube are to reduce skew effect between the supporting rod and a surface of a touch screen when the electronic stylus is held against the surface of the touch screen.

Abstract: A stylus for a capacitive touch screen includes an inverting charge integrator circuit is connected to a conductive tip for providing an output signal proportional to a charge induced at the conductive tip. An inverting amplifier generates an amplified signal proportional to the signal output from the inverting charge integrator. A conductive contact provides electrical or capacitive coupling between the amplified signal and an exterior of the stylus which may provide electrical or capacitive coupling with a person holding the stylus. In other embodiments, the order of the inverting charge integrator and the inverting amplifier may be reversed. A power supply circuit powers the inverting charge integrator and the inverting amplifier. Shielding may be implemented to isolate the stylus circuitry and prevent oscillation. The provided circuitry may enable a ball point or other fine point stylus tip configurations.