Why the Galaxy S10's ultrasonic fingerprint reader matters
Ultra sonic fingerprint readers are here.
The technology promises to be extremely accurate, secure, and speedy, unlocking your phone almost instantaneously.
It won't matter if your finger is greasy, sweaty, wet, or tacky And you won't have to blindly fumble around trying to find the target on the back of the phone.
[BLANK AUDIO] The key to all this is your fingertip, which just like a regular key has all these tiny ridges and valleys that for me, unique pattern that only you possess.
Qualcomm's ultrasonic in screen fingerprint reader claims that it will do a better job unlocking your phone by mapping a 3-D image of your print using sound waves.
So how does it work?
And why is it considered better than an optical sensor that's already on some phones?
Optical and ultrasonic fingerprint readers both start with a sensor just 0.2mm thin.
That's located several layers of technology below the surface glass.
When you touch the glass, your finger sends a tiny electrical pulse that wakes up the sensor to scan your print.
Now the important part is how that sensor performs the scan.
An optical sensor basically takes a 2D photo of your fingerprint, It uses the display to light up the area around your fingertip And sends up a light wave that hits your finger's ridges and valleys, before bouncing back down to the sensor below.
The data is then interpreted as a fingerprint that the phone will match to the one you already have on file.
An ultrasonic sensor, on the other hand, is different, because it uses high frequency sound waves to detect the details of your fingerprint.
This is similar to the ultrasound technology that generates pictures of babies in utero.
And it's also related to how dolphins emit sound waves to locate their prey.
On the phone, it works like this.
You touch the screen, the sensor wakes up.
It sends sound waves back up to your finger that can read four millimeters into the outer layers of your skin.
Because sound waves can penetrate through liquid, it will work even if your finger is wet or gummed up with lotion or french fry grease.
When the sound waves bounce back down, the sensor module converts those wave lengths into electrical signals that are then used to identify your fingers ridges and valleys.
The finish product is a detailed 3D image that is theoretically harder to fool then optical sensor.
Also phones that use an optical sensor can take up to a second to unlock rather than verifying your identity in under 200 milliseconds like an ultrasonic sensor can.
But these ultrasonic fingerprint scanners have an important limit.
They will only work with flexible OLED displays and for now those are only on certain high end phones.
As all the displays gets cheaper, it's possible that Qualcomm's technology will make it's way to more phones.