A number of patents from the likes of Samsung and LG, which show a dual-fold device, have been released.
The first company to show off a real device is a small OEM, whose unnamed prototype features two hinges- an inward and outward folding one. When fully unfolded, the device turns into a full 10-inch tablet.
Now, SlashLeaks has just shared a leaked poster for the Samsung Galaxy Z, which further supports the design rumours.
The resulting Z-shaped device allows for a normal rear cover with cameras at the back and an exposed screen in the front, meaning the folded device merely looks like a very thick smartphone.
For an idea of how a double-folding smartphone works, see TCL’s version below:

Of course, one leaked image isn’t enough to confirm the design for certain; but we’ll see if the device makes an appearance at Samsung’s Galaxy Unpacked event next month.