In-screen fingerprint readers were the standard form of Android biometrics on 2019 flagships, and in 2020 we'll start seeing the second-generation versions of this technology. Qualcomm is hosting its big tech show this week, and one of the first announcements is the new version of its "3D Sonic Max" ultrasonic in-screen fingerprint sensor. The second-gen sensor is absolutely huge. Qualcomm says it's 17 times larger than the previous version.
In-screen fingerprint readers offer the benefit of being invisible and under the screen, and they can go on the front of the device while still allowing for an all-screen smartphone design. Being on the front lets you activate the fingerprint reader while the phone is on a desk, without picking it up. The downside is that there's not tactile guidance for where your finger should go. There's just a big, smooth pane of glass, and if you miss the fingerprint sensor, you're going to fail to unlock your phone. For in-screen fingerprint readers, bigger is better, since a wider target area means less of a chance you miss the invisible reader.
Qualcomm's first in-screen fingerprint reader, available on the Samsung Galaxy S10, was basically as small as it could possibly be: 9mm×4mm. This is much smaller than a fingertip, which is somewhere around 14mm×14mm—you were only scanning a tiny sliver of your fingertip. Qualcomm's second-gen reader is Read More – Source