TCL is an OEM most likely to be familiar for its TVs. However, it also makes other display-based devices, phones included. A patent attributed to this company shows such a device with a screen that can be 'unfurled' due to its flexible panel.
https://www.notebookcheck.net/TCL-may-be-working-on-a-phone-with-an-extendable-display.449196.0.html