(Pocket-lint) - During Oppo's Inno Day in November last year, the company unveiled some interesting concept technology, not least the Oppo X 2021 rollable phone concept.

Now, as part of Mobile World Congress Shanghai, it has shown a bit more of the device - including motion video of its Roll Motor powertrain.

As also detailed at Inno Day, rather than use a flexible panel to make a folding phone like everyone else, Oppo uses its bendable display to hide a portion of the screen inside the phone body. 

Oppo

When needed, the Roll Motor powertrain mechanism allows the screen to unroll and stretch out into a small tablet-sized panel. This particular display goes from 6.7-inches to 7.4-inches, shifting from a long rectangle to a larger, more square design. 

The screen surface has been protected with a bespoke laminate to ensure it doesn't scratch easily, and Oppo says the powertrain is built to last. 

While it's certainly different from the current crop of flexible display phones, Oppo isn't the first company to imagine an unrolling screen in an expanding phone. In fact, TCL showed off its own very similar concept earlier in 2020.

However, thanks to the MWV Shanghai clips, we can see much more on how Oppo's version will look and feel.

In November, Oppo also unveiled AR Glass - its own smart glasses which use OLED displays to project information into your field of view. But, unlike the Oppo X 2021, we're yet to hear any further updates on the details released back then.

Oppo

Oppo said that its AR Glass concept features a dual fisheye camera system for recognising your gestures and is joined by a ToF sensor and regular camera. There's nothing yet to add.

Writing by Cam Bunton and Rik Henderson.