The design in the new patent isn't too unlike Microsoft's abandoned Courier project and comes as rumours persist about its work on Andromeda, a dual-screen foldable device said to run on a version of Windows codenamed AndromedaOS. It's possible Andromeda could be an ARM-based device.
Like the hardware shown in the patent, the foldable Andromeda is said to be designed to mimic a notebook, offering Microsoft a new class of mobile device in addition to tablets and phones. Microsoft filed a similar foldable device patent with a flexible hinge earlier this year.
This patent goes into more details about the mechanics of the hinge. Microsoft describes its "hinged device" as having two "self-regulating" hinges that secure two portions of a device into various positions, not unlike Lenovo's Yoga. The hinges are placed on opposite edges of the device and hold the two screens in place using a gear system.
Folded flat, the device generates a unified user interface across the two displays to offer a tablet experience. When in a 'notebook' position, it creates a virtual keyboard and touchpad on the bottom screen and a usual notebook display on the top screen. The user can then fold the device closed when not in use, or place it in an "alarm clock orientation" when it's idle.
Both hinge patents were invented by Kabir Siddiqui, who's been responsible for several hinge designs at Microsoft. Microsoft filed the patent on October 2016, and it was published on December 14 this year.
It's not clear whether Microsoft will launch a device that looks like the one in this patent. It could, for example, employ the hinge design in future generations of existing Surface hardware.