It seems Apple’s existing legal qualms with Android manufacturers could get even worse, with the Cupertino-based company being awarded another patent, this time dealing with the coveted slide-to-unlock feature.

It’s widely known Apple were the first (if not to introduce, then to make it popular) to unlock a device by sliding across the screen. Now it’s official with the US Patent and Trademarks Office (USTPO) assigning Apple with the relevant patent.

The patent’s number is 8,046,721 and its abstract reads “a device with a touch-sensitive display may be unlocked via gestures performed on the touch-sensitive display.

“The performance of the predefined gesture with respect to the unlock image may include moving the unlock image to a predefined location and/or moving the unlock image along a predefined path.

“The device may also display visual cues of the predefined gesture on the touch screen to remind a user of the gesture,” it said.

It would appear most Android phones currently employ such an unlocking method, and recalling Job’s promise to go “thermonuclear war” on Google, Apple could very well reign litigation all over infringing Android manufacturers.

Currently Samsung’s Galaxy S2 uses an unlocking method which relies on the screen saver being slid off screen, while HTC depends on a circle being dragged to an unlock icon. Sony Ericsson has a two way slide, where one way unlocks the phone and another silences it. The three aren’t alone, with many other manufacturers mimicking the newly patented style.

Read: Samsung’s Plea To Block iPhone 4S Sales Rejected

 Apple’s patent-related litigation has already gone viral, with the company suing Samsung, Motorola and HTC for patent infringements worldwide.