Samsung folding smartphone rumour states 2019 release date, 5 years after teaser video

A 7-inch prototype device has been code named 'Winner', sources claim

Samsung released a video in 2014 that demonstrated a foldable screen concept (Samsung)

The increasingly homogenous design of smartphones could see a major overhaul next year, as Samsung prepares to unveil a phone that folds completely in half.

No official word has been given on the device but a new report suggests Samsung has already built a 7-inch prototype device, which has been code named "Winner".

Two other premium devices – the Galaxy Note 9 and the Galaxy S10 – are set to be launched by Samsung over the coming 12 months, with the folding phone likely to be unveiled in early 2019.

Sources close to the project, cited by The Wall Street Journal, claim the foldable phone will have a large screen that folds in half "like a wallet", as well as a smaller screen on the exterior once it is folded.

While its initial roll-out may be limited, the folding phone could see a wider launch in 2020 if successful.

One of the main motivations of Samsung seems to be to freshen up a stale smartphone industry, which experienced stagnating sales for the first time this year.

Figures released by market researcher IDC revealed that smartphone sales slipped by 0.3 per cent in 2017, marking the first time since the launch of the iPhone in 2017 that sales have declined.

The successor to the Samsung Galaxy S9 could be significantly faster (Getty Images)

Samsung first teased a folding design in a video released in 2014 that demonstrated a phone-tablet concept.

In the years since, the South Korean electronics giant has filed numerous patents describing various ways an organic light emitting diode (OLED) screen could be designed to bend.

Apple – Samsung's biggest rival when it comes to high-end smartphones – is also rumoured to be working on a foldable phone, with several patents for bendy iPhones published by the United States Patent and Trademark Office (USPTO) over the years.

One 2015 Apple patent for a 'Flexible Electronic Device' explains how one such device would include a flexible printed circuit, a flexible battery and flexible display.