An intriguing Apple patent application published today describes how the Touch ID home button could gain additional functionality, allowing it to perform different actions in response to different fingerprints, as well as adding pressure sensors to provide it with 3D Touch type functionality.

The patent goes into a great deal of detail about the technology, with little information as to what it might be used for, but Apple does give a couple of clues. One use of different fingerprints described is to allow someone else to use your iPhone or iPad, but restrict their access to particular apps and for a limited time. The obvious application here would be allowing a child to use only specific apps and/or limit the time they are allowed to use a device …

For example, when the processor matches the fingerprint information against a known fingerprint from an authorized user, the processor can take one or more actions in response thereto. In a first such case, the processor can authorize usage of a device for an individual procedure, for a sequence of procedures, for a selected time duration, until a trigger indicating that the user is no longer authorized, or until the user de-authorizes the device.

A previous Apple patent described how a specific finger could be used to activate a ‘panic button’ feature.

Pressure sensors could also determine what the device does when unlocked, for example immediately opening a particular application when unlocked with a hard press. The home button could also be used to control apps once unlocked.

The user can have a different effect presented in response to a relatively soft touch, in contrast with a relatively hard touch. For a second example, the user can have a different effect presented based on an analog measure of applied force, such as an attempt to turn a dial or wheel, or push or turn a joystick, in a gaming application.

The patent describes ways for the unit to detect not only the amount of pressure applied, but also the direction of that pressure, suggesting that it could act as a kind of joystick.

However, it also goes beyond talk of a home button and seemingly describes how the principles could also be applied to a trackpad to allow many more gestures than currently supported.

A gesture, fingerprint, or applied force may be performed by moving one or more fingers or other objects in a particular manner on touch I/O device 1006 such as tapping, pressing, rocking, scrubbing, twisting, changing orientation, pressing with varying pressure and the like at essentially the same time, contiguously, or consecutively. A gesture, fingerprint, or applied force may be characterized by, but is not limited to a pinching, sliding, swiping, rotating, flexing, dragging, or tapping motion between or with any other finger or fingers. A single gesture may be performed with one or more hands, by one or more users, or any combination thereof.

The patent also references ‘near touch’ gestures, the topic of a separate Apple patent granted earlier this week.

You’re of course familiar with our usual disclaimer that there is no way to predict which of Apple’s patents will ever make it into production, but there are certainly some really interesting ideas in this one.