The smartphone OEM ZTE has reportedly filed a patent with the Chinese National Intellectual Property Office (CNIPA) for a tablet-like device with a screen that can bend at 2 points to collapse into more of a phone form factor. It is not the only manifestation of this concept out there, but does look a very convincing take on it.
https://www.notebookcheck.net/ZTE-reportedly-patents-a-tri-folding-tablet.467181.0.html