How the iPhone's Slide-to-Unlock Gesture Works

Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.

What it covers

This patent describes a method for unlocking an electronic device with a touch-sensitive display. While the device is locked in a 'user-interface lock state,' it displays an 'unlock image,' which is a graphical, interactive object (Claim 1). To unlock the device, a user must make contact with the display and move this unlock image along a 'predefined displayed path' (Claim 1). If the detected contact corresponds to this specific 'predefined gesture,' the device transitions to an unlocked state (Claim 1). If the contact does not match the predefined gesture, the device remains locked and prevents other actions (Claim 2). For example, a user might drag a horizontal slider image across the screen to a specific endpoint (Claim 5, Claim 10).

What it doesn't cover

• —Unlocking methods that do not involve moving a graphical 'unlock image' on the display.
• —Unlocking gestures that do not follow a 'predefined displayed path' (e.g., drawing a freeform pattern or shape).
• —Unlocking by simply tapping or pressing an image without moving it along a path.
• —Unlocking mechanisms that do not require continuous contact with the display, such as voice commands or biometric scans (Claim 4).
• —Unlocking by moving an image to a predefined location without following a specific displayed path.

The clever bit

The novelty lay in combining a visible, interactive 'unlock image' with a specific, 'predefined displayed path' that the user had to follow with continuous contact to unlock the device. This design made it intuitive for users while effectively preventing accidental unlocks from incidental screen touches.

Why it matters

This patent was a foundational element for the user experience of the original iPhone and subsequent touch-screen devices. It provided a simple yet effective way to prevent accidental device interactions while allowing quick access. The 'slide-to-unlock' mechanism became a widely recognized interaction model and was a key subject in major patent infringement lawsuits in the smartphone industry.

Real-world examples

• 1.Original iPhone lock screen
• 2.Early iPod Touch lock screens
• 3.Many early Android smartphone lock screens featuring a slider