I assume there is a not-obvious part. Doesn't there have to be?

Then again, a whole lot of new patents apparently were individually created by taking any existing computer patent and substituting the words "mobile phone" or "mobile device".

What about Microsoft's Courier. That product folds.

It's obvious how to use a flexible display that can change size and flex.
Would they be so nice to patent the technology to create such a display? No luck here boys?

That's a pointless patent - no technology, just an idea every 5y/o would get if he would see such a screen.