With competitors like Lenovo and Samsung already showing prototypes for foldable or bendable mobile computing devices, Microsoft has also started working on a few innovations of its own.

In one application filed with the U.S. Patent and Trademark Office, Microsoft described a portable device with flexible hinges that could allow it to be folded into different forms depending on whether it's used as a phone or mini-tablet.

Another recent patent application by Microsoft described a system for pairing multiple mobile devices so they can share inputs and displays across two or more screens.

Recent reports in the South Korean press indicated that Samsung and LG could come out with foldable smartphones later this year. LG is also said to be planning to produce foldable displays for other companies in 2018.

Folding Display Phones from Samsung, LG Soon?

Consumer tech firms have faced a growing challenge as smartphones become increasingly feature-rich: how to pack in as many capabilities as possible while keeping their devices compact enough to be truly mobile. Among the solutions they've been exploring are different ways to make mobile devices foldable or bendable.

Samsung, for example, could unveil a limited production smartphone in the third quarter of this year that can be folded outward to offer a seven-inch, tablet-like display, the Korea Herald reported last week. Samsung already makes curved-screen TVs and computer monitors, as well as the rounded-edge Galaxy Edge and Edge Plus smartphones.

The Herald added that LG is expected to launch a similar limited production device in the fourth quarter. A separate report in Korea's etnews last month noted that LG plans to begin production of similar displays in 2018 for customers, including Apple, Google and Microsoft.

Microsoft Trying To Eliminate Size-Portability Tradeoffs

According to a patent application filed in October 2014, Microsoft is also working to develop a flexible form factor device that can be used as either a smartphone or mini-tablet, or can be folded together to protect the screen. The application, which named Microsoft lead engineer Kabir Siddiqui as the inventor, said that such flexibility could eliminate the tradeoffs consumers often make when shopping for mobile devices.

"The size of a display device has been found to be a major consideration by consumers regarding a choice of which mobile computing device to buy, whether to purchase multiple mobile computing devices, and so on," according to the application. "For example, a user may be forced to balance portability of a mobile computing device having a relatively small display device (e.g., a mobile phone) with increased viewability afforded by larger display devices included on relatively large mobile computing devices, e.g., tablets."

Siddiqui's concept device would have a flexible hinge structure that could allow a user to unfold an OLED screen to lay flat like a tablet, and fold it up again for smartphone-like portability, the application noted.

In September, Microsoft also submitted a patent application for a "multi-device pairing and combined display." That idea, developed by Kenneth Hinckley and Koji Yatani, could enable users to combine multiple mobile devices so they could input information and commands on any of those devices and view interfaces and outputs that appear seamlessly across several displays.