US 9933866

US Patent 9933866, titled "Active stylus with high voltage," was granted to Wacom Co Ltd. The patent lists Shahrooz Shahparnia, Kishore Sundara-Rajan, Yassar Ali, and Izhar Bentov as its inventors. The application for this patent was filed on October 17, 2014, and the patent was issued on April 3, 2018.

Abstract:
The patent describes a stylus that includes one or more electrodes and computer-readable non-transitory storage media embodying logic for wirelessly transmitting signals to a device's touch sensor. Some of these signals are high-voltage signals, characterized by a significantly larger potential difference compared to the stylus's normal operating voltage range of approximately 1 to 3 volts. The stylus also contains a component designed to convert the 1-3 volt range voltage to this higher voltage. One or more of the electrodes are located at the stylus tip, and these electrodes receive the high voltage to generate the high-voltage signals.

Independent Claims Overview:

• Claim 1: This claim describes a stylus that includes electrodes, a computer-readable non-transitory storage medium with logic for wirelessly transmitting signals (including high-voltage signals) to a device's touch sensor, a component (such as a transformer) to convert a standard 1-3 volt operating voltage to a higher voltage, and a stylus tip where some electrodes are located. The key aspect is that these high-voltage signals are a result of the electrodes at the tip receiving the converted high voltage.

• Claim 8: This claim is similar to Claim 1 but specifies that the transmitted signals are "electromagnetic" and explicitly states that the high voltage is "based on a voltage difference between a drive line of the touch sensor and a sense line of the touch sensor." It also includes electrodes and a stylus tip where they are disposed, and the high-voltage signals originate from these electrodes receiving the high voltage.

• Claim 15: This claim focuses on the one or more non-transitory computer-readable storage media embodying logic. This logic, when executed, enables the stylus to transmit electromagnetic signals, including high-voltage signals, to a device's touch sensor. The stylus described within this claim also features one or more electrodes for wireless transmission, a component to convert 1-3 volts to the high voltage, and electrodes at the stylus tip. The high-voltage signals are generated when these tip electrodes receive the high voltage.

Litigation Information:
As of April 26, 2026, the patent has been involved in litigation. A case was filed in the Texas Eastern District Court, and a PTAB case, IPR2025-01495, was filed but not instituted procedurally. My search did not yield specific dockets for this patent in the CAFC for 2026.