The application, called Cover Attachment with Flexible Display and originally filed on Aug. 11, 2011, describes a cover with "at least a portion of the flexible flap" covered by a display for visual information. A communication channel and power connection link it to the tablet .

'Room for Improvement'

The cover apparently could be used as a full secondary display to the main tablet screen, or, when folded and used as a tablet stand, could provide alternative playback controls in a portion of the cover or could show additional information, such as subtitles for the main screen. It could also become a full touch-screen keyboard.

The application also shows the possibility that one horizontal portion of the flexible cover could display handwritten notes, such as from a stylus or a finger on a screen. The application description notes that, while tablets allow "an extensive variety of tasks to be performed, the overall functionality of this device type" still has room for improvement.

For instance, the application states, "increasing the display area could lead to a significant expansion in functionality." However, the application points out that increasing the existing display area would require increasing the device size, which would reduce its portability.

If Apple's patent application ever became reality, it wouldn't be the first two-screen tablet -- although it could be the first where one of the screens could be folded over and used in connected segments. There are several, barely known two-screen tablets. For instance, Sony has one out, a small dual screen device called the P Tablet. Acer has released a pricey, $1000+ dual screen TouchBook, and there are models from Kno, Toshiba and others.

The Late Courier

But the best-known antecedent was Microsoft 's famed Courier tablet prototype.

That tablet never was actually announced by the Redmond, Wash.-based technology giant. In fact, it may never have existed in what we call reality, although it became a vision to technology dreamers for a while. In months prior to the spring of 2010, it was known exclusively through leaked photos and a video. The video showed an innovative, two-screen tablet device, with screens that could act as one large, virtual desktop.

In April 2010, Microsoft executives were reported to have told its internal team that the project was dead. A Microsoft official told news media at the time that the company is always developing new ideas and that such a device would be evaluated in the future.

But, even if it never actually existed as hardware, Microsoft may have the last laugh. While Apple is trying to get a patent for a screen display in the cover, Microsoft has received a patent for the Courier's two-screen design.

Gift Suggestion: Give your favorite children the gift of an amazing adventure in reading. Check out one of the hottest new series of the year: The Mason Dexter Adventure Series chronicles the adventures of Mason Dexter, a resourceful middle-school boy who builds amazing tech gadgets and saves America from impending doom. The Mason Dexter Adventure Series is available now on Amazon.com. Perfect to read on the iPad, Kindle, Android eBook readers, or any computer with Amazon's free Kindle app.