Tablets have seen an ongoing decline in popularity in recent years, with phablets largely serving the needs of consumers who desire a larger-screened mobile device. Microsoft appears to be experimenting with a novel way of making tablets relevant again by incorporating them right into smartphone design, as depicted in a recently-unearthed patent.

The document describes a mobile device with two displays connected by flexible hinge, similar to what we've seen in patents for the Samsung Galaxy X smartphone and conceptual devices from Apple. The hinge allows the device to be folded into different form-factors based on the need of the owner.

The result is essentially a conventional take on the clamshell flip-phone, with images accompanying the patent showing a large smartphone-like device that can be folded out into a tablet, notebook and even a 'tent' mode as per Lenovo's 2-in-1 Yoga range.

The patent, spotted by MS Power User, notes how such a device would negate the need for users to buy several gadgets to fulfil various purposes, with the conceptual all-in-one smartphone instead covering all the bases.

"Conventional mobile computing device form factors often forced a user to make a choice regarding a form factor that may involve a compromise between these form factors (e.g a "phablet"), purchase of multiple devices, and so on," the document reads.

"A user, for instance, may purchase a mobile phone having a relatively small display device to make phone calls, text, and so on. If a larger display device is desired, a user may also purchase a tablet to answer emails, browser the Internet, and so on."

It's important to note that Microsoft filed the patent in October 2014, meaning it may since have abandoned the idea. That said, the company is known to be working on something big to shake up the smartphone market, with Microsoft CEO Satya Nadella referring to "the ultimate mobile device".

If the patents hold water, Microsoft would be joining the likes of Samsung, Apple, LG and Nokia in experimenting with new smartphone designs that go beyond the basic square slab we've become so familiar with.