Apple has won another crucial patent for its multitouch technology, as Patently Apple finds, that will add to its already deadly legal arsenal against Android competitors. The patent approved today involves oscillating signals and is one of the "200+ Patents for new inventions" that Steve Jobs first alluded to when the first iPhone debuted.
This patent focuses on the oscillator signal and circuit of a touchscreen, technology that is integral to how users interact with a multitouch device. Previous resistive touchscreens can only recognize a single touch input no matter how many objects are touching the screen. Capacitive touchscreens can rely on oscillating signals to track inputs over a substrate but creating a precise ciruit-based oscillator is difficult.
Apple's patent provides a solution that uses calibration logic circuitry that compares signal oscillation against a reference signal and then accordingly tunes its clock frequency. This offers an accurate capacitive display that can detect multiple touches as well as hovers and near touches.