MojoKid writes "Apple may be looking to improve upon the stylus as we know it today. The Cupertino company filed a patent application with the USPTO for what it calls an 'Active Stylus,' which can be used on capacitive touch sensor panels like those found on the iPhone, iPad, and iPod Touch devices. 'Unlike conventional styluses which work passively by blocking electric field lines between the drive and sense electrodes of a capacitive touch sensor panel, the styluses disclosed in the various embodiments of this disclosure can either act as a drive electrode to create an electric field between the drive electrode and the sense lines of a mutual capacitive touch sensor panel, or as a sense electrode for sensing capacitively coupled signals from one or more stimulated drive rows and columns of the touch sensor panel or both.' According to Apple, active styluses allow for more accurate input without driving up cost."
Quantum Mechanics is a lovely introduction to Hilbert Spaces!
-- Overheard at last year's Archimedeans' Garden Party