A recently published patent filed by Microsoft describes in detail the hinge mechanism supporting a pop-up dual-surfaced foldable display. The patent also hints towards edge display notifications.
Hinged display RSS
New APIs added in the latest build released to Insiders show Microsoft is adding features enabling its OS to run on devices featuring 360-degree rotation, the most likely candidate being Andromeda.
Apple patented a dual-screened, low-reflective display design where the secondary screen may be attached magnetically or via a hinge and serve as a keyboard for MacBook laptops or iPad Pro devices.
While one shouldn't read too much into a patent leak, the frequency of these hinged display patents are growing for the Redmond company. The latest one was filed in 2015 and was made public yesterday.