With the appearance of folding screens, many technology companies are pursuing devices with innovative, breakthrough designs that have never been before. After Google submitted the invention of a device with multiple layers of folding screens like a book, IBM was also approved for the invention with a smartwatch with a screen with the ability to expand into a smartphone or tablet when needed.
This patent was submitted by IBM since 2016, but it was only recently approved. Normally, the in-patent device will act as a smart watch with a compact screen. However, when needing its screen, it can be enlarged 4 or 8 times to become a smartphone or tablet depending on needs.

To achieve this capability, IBM's equipment equipped with a special screen with rectangular panels can be stacked and spread out in different sizes when needed. Although providing many different screen sizes for different purposes, the disadvantage of this device is that it exists unsightly contours at the junction of the screen panels.
However, this design is hard to come true, at least with the current level of technology. If you want to commercialize a product like this, IBM needs more advanced technical solutions in the future.