There has been several prototypes of foldale smartphones Samsung has patented and has been granted all the way long from 2013 to 2018.
Now rumors in China are saying at this time that Samsung has 3 prototypes and will unveil one at CES 2019 but will only launch between 700.000 to 1.200.000 units at the begining. The launch/release date might be in the 1Q 2019.
This prototype has 7 inch diagonal (two 3.5 inch) when it is unfolded and Samsung is sending specifications and contents to high-end part suppliers, meaning it will not be cheap.
Before related posts:
Samsung Patent for a Multi-Folding tablet with phisical keyboard was granted.
Samsung files a patent for a both sides expandable display smartphone.
Samsung wins patent covering a fold-out smartphone. Desing same as showed at CES 2013. Video.
Samsung patents a rollable display device with fingerprint sensor.