Yesterday was a wildly exciting day for Windows fans around the world. Microsoft introduced two foldable devices that will be coming to market in about a year's time. The first was an all-new foldable tablet branded Surface Neo. The second was an all-new smartphone that they've branded Surface Duo.

One key accessory designed for Surface Neo is a magnetic keyboard that attaches to the backside of one of the displays. When needed, a user can easily move the physical keyboard accessory by flipping it to the front which partially covers one of the two displays so that users could use it as a mini laptop.

That specific feature is highlighted in the Microsoft video below. The video is set to start exactly as the keyboard is flipping from the back to the front, partially covering one of the displays.  

This feature is briefly covered in a new Microsoft patent application published by the U.S. Patent Office (USPTO) today covering a hinge design.

Microsoft's FIGS. 2A and 2B below collectively show device 100A (now known to be Surface Neo). The device adds a deployable assembly #202. In this example, the deployable assembly is hingedly attached to the distal end 114 of second portion housing 126(2).

Microsoft's patent FIG. 2A shows the deployable assembly deployed. FIG. 2B shows the deployable assembly rotated (as indicated by arrow 204) to a storage position against the first surface (#122) of second portion (#104).

A similar patent that we covered back in April presents the same type of hinged device without the added section that was presented in patent figures 2A and 2B today. This is a unique addition.

Without seeing Microsoft's keynote yesterday showing the Surface Neo with a flippable keyboard accessory, I wouldn't have known what FIGS. 2A and 2B were referring to in this latest patent application because Microsoft never explains what adding a "deployable assembly" would actually translate to.

Thanks to yesterday's presentation, it's just another piece of Microsoft's foldable device patent puzzle solved just in time.