Samsung finally unfurls its folding phone screen prototype.

Samsung's long-rumoured folding-display phone has finally become a reality – well, almost. During the keynote for the 2018 Samsung Developer Conference (SDC) today, the company demoed a prototype of what it calls the Infinity Flex Display, which can unfold from smartphone- to tablet-sized.

Justin Denison, Senior Vice President of Mobile Product Marketing at Samsung, took to the stage towards the end of the 100-minute keynote to show off the basic details of the prototype. The Infinity Flex Display prototype starts off like a regular phone with a familiar-sized touchscreen that functions as you'd expect.

But the kicker is that this fairly normal screen sits on the outside of a clamshell design, which opens up to reveal the larger, bendable display inside. Fully extended, this inner screen is a more tablet-like 7.3 inches.

To make use of this unusual layout, Samsung is developing a new interface it calls One UI. With this, whatever app is being used on the outer screen will quickly carry across to the inner screen once opened. Up to three different apps can be used at once on the larger screen, so you can watch a video on one half while typing a message or browsing Facebook on the other.

Samsung did seem to want to keep some details in the dark – literally. The stage lights were dimmed during the demo, so that the screen itself was clear but the device around it wasn't. From what we can tell though, it looks like the thing has fairly chunky bezels around the screen, flying in the face of the trend towards edge-to-edge displays. We're also curious about what, if anything, the smaller screen can do from the back, while the device is unfolded.

Denison went into a little detail on the mechanics of building the Infinity Flex Display. Obviously, glass isn't particularly flexible, so Samsung abandoned it in favor of a new material that, according to Denison, is "an advanced composite polymer that's both flexible and tough." That display is made up of a cover window, shock-absorbent film, polarizer and backplane, which are all made to bend, and are stuck together with a new type of foldable adhesive that keeps the layers together through hundreds of thousands of folds.

There's no word yet on if Samsung will be releasing a consumer device with an Infinity Flex Display in 2019, but Denison does say that the company will be ready to mass produce these foldable displays in the coming months.

If that's the case, 2019 is shaping up to be the year of the folding phone. Huawei and LG have already announced intentions to launch flexible phones in the next 12 months or so, and just last week Chinese manufacturer Royole unveiled the FlexPai. This looks pretty similar to Samsung's but actually folds in the opposite direction, so the screen would be on the outside at all times.

The Infinity Flex Display was the headliner of the keynote at SDC, but Samsung also detailed a few other things. One UI is also set to come to other Galaxy devices running Android 9 Pie, with its key function being to move the most relevant stuff to the bottom half of the screen, making it easier to reach everything when using the device one-handed.

Check out the opening keynote in full below, or skip to the 1 hour 23-minute mark to watch the Infinity Flex Display reveal.

Source: Samsung