It appears that Apple might be preparing to take biometric identification to the next level in an upcoming iteration of its mobile devices.

Following on the success of fingerprint ID on its recent iPhone and iPad models, the company has been granted a U.S. patent for technology that employs facial recognition to unlock and lock a device — entirely without the use of buttons.

According to the summary for U.S. Patent No. 8994499:

In an embodiment of the invention, a mobile device is configured to automatically lock based on determining that a user's face is no longer present in images captured by the device's built-in camera. For instance, consider that the device is initially unlocked. In that state, a built-in camera captures one or more images, and the images are then analyzed to determine whether a user's face is present therein. If a user's face is not present in the images captured over a predetermined amount of time, the device automatically locks. ...

In another embodiment, a mobile device is configured to automatically unlock. Consider that the device is initially locked. In that state, the camera captures an initial image. When movement of the device is detected, the camera captures a new image. The device then determines whether it has moved to a use position (i.e., a position that indicates that a user is likely to want to use the device) by comparing the new image with the initial image. If the device has moved to a use position, the camera captures a subsequent image, and the subsequent image is analyzed to detect a user's face. If a user's face is detected in the subsequent image, the device is automatically unlocked. ...