Those who feel that Microsoft’s most innovative days are behind them might want to reconsider that opinion as a string of recent patent applications suggest otherwise. The latest idea from Redmond involves adding a secondary screen on the back of a smartphone to display information that would otherwise require the user to turn on the main display.

The idea is that a secondary, low powered (think e-ink) display could be utilized on the rear of a smartphone that would work in tandem with the handset’s primary screen. By showcasing information like the time, e-mail or text message notifications or WiFi signal strength, the user wouldn’t have to activate the main display as often, resulting in improved battery life.

Patent Bolt suggest that a smartphone equipped with a secondary display could be run by a low-power processor, again reducing overall power consumption as the primary processor wouldn’t be required to perform calculations for the extra screen.

Of course, this idea isn’t exactly new as many clamshell phones offered a secondary outer display to show the time or a new message notification, but we can’t recall a modern-day smartphone using similar technology.

Either way, it seems that dual display smartphones are coming at some point down the line.  A concept video from Nokia that surfaced late last year suggests that every surface of future phones could be touch sensitive. A similar patent from Samsung would use additional screen real estate as a smart skin of sorts, wrapping around the entire device.