Apple granted slide-to-unlock touchscreen patent

Apple has been granted a patent on touchscreen on the 'slide to unlock' technology used by almost all tablets and smartphones, in a move that could spark a new war of ligation against rival Samsung and others.

Patent number 8,046,721, granted today by the US Patent and Trademark Office, covers the ability to unlock a device using an on-screen gesture. The filing reads: "A device with a touch-sensitive display may be unlocked via gestures performed on the touch-sensitive display. The device is unlocked if contact with the display corresponds to a predefined gesture for unlocking the device.

"The device displays one or more unlock images with respect to which the predefined gesture is to be performed in order to unlock the device. 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."

It's an extraordinary move, and one that is bound to have widespread repercussions: the system is one that's employed on pretty much every touchscreen device on the market. Manufacturers who build the feature into their smartphones or tablet devices risk infringing the patent - leading to possible legal action from the Cupertino-based IT giant.

Apple has already been waging a proxy war on Google's Android platform, targeting prominent manufacturers who us the OS - notably Samsung, whose Galaxy Tab 10.1 has been temporarily banned from sale in a number of countries including Australia and Germany. Other tablet devices, such as Barnes & Noble's Nook e-book reader have been targeted, while other makers including smartphone maker HTC have been persuaded into patent licensing agreements with Apple.

In a soon-to-be-released authorised biography, late Apple CEO Steve Jobs is quoted as vowing to destroy Android "to his last breath", claiming that Google's mobile OS was built on ideas stolen from Apple.