Apple has applied for a patent on having an additional display, possibly with touch input, built into a flexible cover for the iPad.

The application was filed last year but has only just been made public by the US Patent & Trademark Office. It appears to be an enhanced version of the design used for the optional cover with the third generation iPad which works like a plastic folder for the device and puts it into standby when closed.

The design places “thin flexible display technology” into the inside face of the cover, which Apple notes could add functionality without making the iPad any bulkier or significantly heavier.

The key to the technology is a magnetic hinge that not only holds the iPad in place in the case, but also supplies power from the iPad to the case, as well as housing a data connector.

Exactly what Apple would use this for is somewhat vague in the patent filing, with a range of different ideas put forward. The simplest are that the extra display could house an ‘overspill’ of app icons from the main screen, or that it could act as a form of notification bar when the user is running an app in full-screen mode.

More ambitious ideas are that it could incorporate touch recognition and be used as a control panel for operating media playback, a virtual keypad, or could even work as a graphic panel with a stylus.

It’s important to remember that this is only a patent application and that there’s no guarantee Apple will ever release. Indeed, given the design and suggested uses are so general, it may simply be a case of taking an “obvious” development and sticking in a patent application just to be on the safe side.