The US Patent and Trademark Office issued a new design patent to Apple on electronic page turning last week, and it's certainly a bizarre one, but it's not as menacing as some have reported. Apple doesn't now own the page turn. While US patent D670,713 isn't exactly a narrow patent, there are some real limitations on what it covers and how it could be used against the competition.

As with all design patents, we have to look at the drawings, understanding that only the solid lines define the coverage. But there is another consideration in play with this one that we don't often see: animation. Think of the D'713 patent as a very basic flip book depicting the type of virtual page turn claimed (shown below). It may be tempting to look at all of this as essential to emulating physical page turns on a device, but the patent simply isn't that broad.

Most of us are familiar with the numerous ways a page in iBooks can be manipulated and folded, but we have to be careful not to confuse what we know about Apple's software with what this patent covers. The drawings make it clear that the bottom-right corner is being pulled to lead the way and that the paper is folding over at a fairly consistent angle along its length — in contrast to a more drastic corner fold or a turn initiated at another part of the page, for instance. That's just one way to represent a page turn. One of many.

It's also important to note that the scope of a design patent is limited by what came before it. In this case, the virtual page turning methods known before the 2010 priority date of the D'713 patent are highly relevant. Patents granted to companies like Microsoft, Adobe, and even Apple, were cited during the USPTO's examination process and demonstrate that the emulation of physical page turning on electronic devices isn't new and this patent is necessarily limited by that history. Unless a competitor exactly copies this particular turning animation — and key players like Amazon and Barnes & Noble have not — it's not likely to be used as a powerful weapon in future litigation. It's more like a single arrow in Apple's ever-growing patent quiver, for whatever that's worth.