https://www.cnet.com/news/vivos-apex-2019-lets-you-can-scan-your-fingerprints-anywhere-on-the-screen/

We know the front and rear of the Apex 2019 are covered in Gorilla Glass, but Vivo wouldn't disclose which version of the glass it's using. It's main claim to fame is that it uses a full-display fingerprint sensor -- you can touch the screen anywhere to unlock the phone. Vivo suggests adding a second finger for enhanced security, but the test phone unlocked with just one fingerprint when I tried to test the feature. That's because there were other prints already registered.

Making the whole screen unlockable gives Vivo more options on the unlock screen. There are apps you can tap to unlock and load straight away. When you touch the screen, the pixels in the area will light up, helping the reader under the screen see your print more clearly. This is supposed to help speed up the scanning process, but the process was already quick enough.