One of the biggest stories out of this year’s CES, and the recipient of our Best in Show award, was a prototype phone from Vivo that showed off the world’s first in-display fingerprint scanner. This is a method of biometric authentication that could prove to be the best of all worlds — no need for bulky screen bezels, awkward rear-mounted sensors, or complex arrays of face-detection tech. That prototype later shipped in China as the X20 Plus UD, and now Vivo has brought a concept phone to MWC that represents the next evolution of that idea. It's all about figuring out how to get rid of bezels for good.

The concept phone is called Apex, and its headline feature is what Vivo describes as “Half-Screen In-Display Fingerprint Scanning Technology.” The idea here is that instead of placing your finger on a thumbnail-sized icon to unlock the phone, you’ll be able to do so in a much larger area of the display.

On Apex, the usable scanning area isn’t quite half the screen — it’s more like a third. Or maybe two-fifths. But in any case, the area is big enough to demonstrate the tech's advantage; this way, you can pretty much just pick up the phone and unlock it without really having to think about it. You're also able to require simultaneous input from two different fingerprints for extra security, or for times when you might want to protect data shared by two people.

Vivo isn’t saying whether the scanner is provided by Synaptics, as was the case with the X20 Plus UD. (My guess would be yes.) It works the same way, requiring an OLED screen and the ability to light up the surface of your finger upon contact. It isn’t quite as fast as a conventional fingerprint reader, and I actually found that it works better if you press your thumb flat against the screen rather than only using the tip. The important thing, though, is that it works.

All of this is in service of the war on bezels

All of this is in service of the war on bezels that almost the entire smartphone industry has declared over the past year or so. Apex, as a device, is one of the most aggressive expressions of that ideal yet, with almost imperceptible bezels around three sides of the phone and a larger — but still skinny — one on the bottom edge. And as such, Vivo has needed to find solutions for the kind of features that’d usually require bezels to function.

The most obvious one of these is the selfie camera. Some phone makers have gotten around this with notches, others by relocating the camera below the screen so that you have to hold the phone upside down. But Apex’s answer is both inventive and kind of cute — the 8-megapixel camera is hidden behind the screen and pops up like a periscope when needed. It takes 0.8 seconds to ready itself and makes a little whirring sound — I thought the mechanism would be flimsy, but it actually feels really solid. If nothing else, it’s a neat way to avoid the notch.

The lack of bezels also means there’s no space for a conventional earpiece speaker. Xiaomi’s Mi Mix addressed this with a piezoelectric design that worked similar to bone conduction technology, but Vivo’s approach here is to vibrate the entire screen itself like a speaker — you can still hear phone calls without holding the device to your head. I’ve heard better quality calls in my time, but it’s totally usable.

Apex is purely a concept, and Vivo says it has no plans to release an actual product in this particular form. But none of it feels particularly implausible. The fingerprint sensor works, the selfie camera works, the earpiece-speaker-thing works, all in a package with an impressive screen-to-body ratio. I wouldn’t be surprised if one, some, or all of these ideas make their way into various phones over the next year or two as manufacturers chase a future free from bezels.