Apple's invention could be configured to interface with a touch-based user interface device such as a touchscreen, says the patent summary. The tip of the device could be pointed, blunt, or configured as a ball that rolls along the touchscreen surface.

Apple describes that the stylus could have orientation sensors that can detect when the iPen rotates allowing thinner or thicker lines, darker or lighter marks, for example. The sensors could also be used to change the volume of the touchscreen device, for example.

Apple has also designed the iPen to have a mini-speaker built-in, which will give the user audio feedback.

Patently Apple explains that the iPen could be used in conjunction with Apple's own new graphics editing program, which may be similar to Autodesk's Sketchbook for example.

filed for by Apple describes an optical pen that uses a camera, for example, to determine the movement and location of the stylus in relation to a touchscreen. This device could have a pointed tip for precision input to improve writing on an iPad, for example.