Technology for an advanced Apple Pencil has been spotted in a patent document, and it describes the use of a trackball tip and optical sensors.

If Apple brings this idea to life, the Apple Pencil could soon become more than just a stylus, it could be a controller for ...

According to the filing, named Input Device with Optical Sensors, the Apple Pencil could in future work with optical sensors across a wide range of surfaces, potentially including the iPhone, MacBook ...