Microsoft has filed a patent for a mobile phone dual display, but unlike the products that already have this type of screen the solution of the US-based plan to use the entire floor area. Not only the front and rear, as you can see from the video (produced by Nokia), also the sides are used: in this way you can use all the space and can devote several areas to icons or specific applications.
The ideas at stake are varied. The first is to use a screen with low consumption, such as a display based on technology and-ink, which will be proposed secondary information such as those present in a common status bar. You could use the back when using the camera, then; for example, display the countdown or even the same frame.
The secondary monitor, then, can be managed by a dedicated processor, maybe less accurate not to affect battery life. In any case we believe the idea is very interesting, even if we see with our eyes the cosmetic result (very important parameter for the success of a phone) and its objective function.