Vivo Shows Off World’s First Phone With In-display Fingerprint Scanner

After a string of teasers over the past month, the world’s first smartphone with an in-display fingerprint sensor has been made official at CES 2018 in Las Vegas. The first to introduce this technology is Chinese phone maker Vivo.
Unveiled at CES 2018, the technology is not a prototype but an actual working device that comes integrated with Synaptics’ ClearID in-display fingerprint scanning tech. While it may sound like black-magic, the sensor isn’t much different than your usual fingerprint sensors.

How It Works

When you take Vivo’s new smartphone in your hand, you’ll notice that it’s just a chunk of metal and glass with no fingerprint sensor on the back or even the front. You just need to wake the screen and the phone will explicitly tell you where the finger needs to be placed to authenticate by displaying a graphical fingerprint UI at the very bottom of the screen.
If you were hoping to unlock the phone simply by placing your finger in the general area of where the fingerprint sensor resides, well it seems that’s not an option. You’ll first have to wake the device and then scan your finger to unlock.
Then, all you need to do is press your registered finger on that impression and voila, the phone has been unlocked. It works in a manner similar to the capacitive fingerprint scanner, but will now make it possible for the phone makers to design more aesthetically pleasing phones. There would no longer be a circular sensor at the rear or front, the ones we’ve gotten used to, and it is a good thing.

The Tech Underneath

We did have an inkling of ongoing work in the said department but Synaptics’ in-display sensor was first revealed earlier last year. Vivo is just one of the five Tier-1 hardware makers that Synaptics said it is working with to implement the new biometric technology.
As you can see in the image below, the fingerprint scanner has been sandwiched between the OLED panel and the glass of the display, which would then have been connected to the internals.
The in-display fingerprint sensor has an optical image sensor that scans the image of your finger. This data is then passed onto an AI processor that’s said to be trained to recognize 300 different characteristics of your fingerprint. This is core technology which helps the sensor to distinguish between different users.

How in-display fingerprint readers work

In fact, the fingerprint sensor -- made by sensor company Synaptics -- lives beneath the 6-inch OLED display. That's the "screen" you're actually looking at beneath the cover glass. You can see it in our photos here.
When your fingertip hits the target, the sensor array turns on the display to light your finger, and only your finger. The image of your print makes its way to an optical image sensor beneath the display. 
It's then run through an AI processor that's trained to recognize 300 different characteristics of your digit, like how close the ridges of your fingers are. It's a different kind of technology than what most readers use in today's phones. 
Synaptics, which demoed the Vivo phone in a crowded booth at the back of an interminable hallway, says that the fingerprint reader won't suck up much more battery by illuminating your finger, promising that its power management is equal to industry standards.
Because the new technology costs more to make, it'll hit premium phones first before eventually making its way down the spectrum as the parts become more plentiful and cheaper to make.
Vivo's phone is the first one we've gotten to see with the tech in real life, but it's clear this is just the beginning.