Edge-to-edge screens are poised to be the new hotness of smartphone design in 2018, but pushing pixels right out to a device's borders leaves little room for the range of sensors we've come to know and love on the front of a phone—especially fingerprint sensors. By all accounts, Apple is dealing with this new reality by gradually retiring the fingerprint as a biometric input. You can still get a Touch ID sensor on an iPhone 8 or some MacBook Pros, but the future as seen from Cupertino clearly relies on Face ID, its array of depth-mapping hardware, and the accompanying notch.
Fingerprint sensors still have some advantages over face-sensing tech, though. They allow owners to unlock their devices without looking directly at the front of the phone, an important capability in meetings or when the device is resting on a desk or table. They can't be tricked by twins, and they can't be as easily spoofed as some less-sophisticated forms of facial identification. It's simple to enroll multiple fingerprints with most fingerprint sensors, as well, whereas Face ID is limited to one user at the moment. I appreciate being able to enroll several of my ten fingers with my iPhone to account for my left and right hands, for example, while other owners might enroll a spouse's fingerprint for emergencies. Ideally, we'd have both technologies at our disposal in the phones of the future.
Some Android device makers have been coping with the demand for ever-shrinking bezels by introducing less-sophisticated facial unlock schemes of their own, but the overwhelming majority of serious biometric inputs on those devices comes from a fingerprint sensor on the back of the phone. Sometimes those back-mounted sensors are placed well, and sometimes they aren't. As a long-time iPhone user, I believe that the natural home for a fingerprint reader is on the front of the device, but edge-to-edge displays mean that phone manufacturers who aren't buying Kinect makers of their own simply have to put fingerprint sensors somewhere else.
The intensifying battle between face and fingerprint for biometric superiority, and the question of where to put fingerprint sensors in tomorrow's phones, is fertile ground for Synaptics. You might already know Synaptics from its wide selection of existing touchpad and fingerprint-sensing hardware, and last week at CES, the company made a big splash by showing off the first phone with one of its Clear ID under-screen fingerprint sensors inside: a model from Vivo, a brand primarily involved in southeast Asian markets.
The demo Vivo phone. Fingerprints go on the glowing blue spot.
In short, Clear ID sensors let owners enjoy the best of both edge-to-edge screens and front-mounted fingerprint sensors by taking advantage of the unique properties of OLED panels to capture fingerprint data right through the gaps in the screen's pixel matrix itself. Clear ID results in an all- (or mostly-) screen device with no visible fingerprint sensor on its face and no notches for face-sensing cameras at the top of the phone. We covered Clear ID in depth at its debut, but I was eager to go thumbs-on with this technology in a production phone.
What's most striking about Clear ID is how natural it feels to use. Enrolling my fingerprint required the usual lengthy sequence of hold-and-lift motions that most any other fingerprint sensor does these days. Once the device knew the contours of my thumb, though, unlocking the phone proved as simple and swift as resting my opposable digit on a highlighted region of the screen that's always visible thanks to the self-illuminating pixels of the Vivo phone's OLED panel. The process felt as fast as using Touch ID on my iPhone 6S, and it may even have been faster when I got the phone in a state where it would unlock without playing the elaborate animation you see above.
In the vein of the best innovations, Clear ID feels like the way fingerprints ought to be read on phones with edge-to-edge screens, and it'll likely serve as a distinguishing feature for device makers planning to incorporate OLED panels in their future phones. The backlight layer of LCDs won't let fingerprint data pass through to Clear ID sensors, so the tech won't be coming to phones relying on those panels yet, if it ever does. Clear ID is so obvious and natural in use that it was my immediate answer when folks asked about the most innovative thing on display at CES, and I'm excited to see it make its way into more devices soon.