Patent 8481872 was granted and assigned to N-Trig on July, 2013 by the United States Patent and Trademark Office.
A method for operating a digitizer with an autonomous asynchronous stylus includes sampling outputs from a digitizer, detecting from the outputs at least one pulsed signal transmitted from an autonomous asynchronous stylus at a defined rate, determining a location of the stylus interaction with respect to the digitizer, and tracking stylus interaction with the digitizer over subsequent pulsed signals transmitted from the stylus.