The latest manufacturer that is entering the race of foldable screen in smartphones is Oppo, which just patented a similar phone design.
It has an outward hinge that, once unfolded, will act as a part of the screen.
The patent entry also suggests there will be a dual camera on the back of the unfolded Oppo. When closed, one of the sides can be used for making calls, while the other can be used for taking selfies with the front camera.
The patent renders by Oppo are just for illustration purposes