The Galaxy S10's in-screen fingerprint scanner may look just like one on the OnePlus 6T, but do not be fooled. Samsung's flagship Galaxy S10 and S10 Plus are the first phones to use Qualcomm's ultrasonic in-screen fingerprint technology, which uses sound waves to read your print.
Related to ultrasound in a doctor's office, this "3D Sonic Sensor" technology works by bouncing sound waves off your skin. It will capture your details through water, lotion and grease, at night or in bright daylight. Qualcomm also claims it's faster and much more secure than the optical fingerprint sensor you've seen on other phones before this. That's because the ultrasonic reader takes a 3D capture of all the ridges and valleys that make up your skin, compared to a 2D image ̵
The debate between ultrasonic and optical fingerprint scanners comes at a time when biometric security is on the ascent. In-screen fingerprint readers have a hot trend in phone design because they do not take up any room on the phone face, and require less groping around than a sensor embedded on the phone's power button or back casing. That design coincides nicely with the move towards an all-screen face with barely visible bezels.
"Security and biometrics have been integrating into mobile platforms at a rapid pace," said Alex Katouzian, senior vice president of mobile technology at Qualcomm, in December at Qulalcomm's annual tech summit in Hawaii. "This is the future of fingerprint technology."
The ultrasonic fingerprint sensor built into the screen layers replaces iris scanning as the biometric sensor of choice on the Galaxy S10 and S10 Plus in particular. (The Galaxy S10E has a traditional capacitive fingerprint reader on the power button.) Iris Scanning has existed since the Galaxy S7, so Samsung's move away is a surprise about-face. Rumor has it that Google could fold 3D face scanning into the Android Q .referred to as
For an animated explanation of how ultrasonic fingerprint scanners work, be sure to check out the video in this story. Meanwhile, here's what you need to know about the ultrasonic fingerprint reader on the Galaxy S10 and S10 Plus
What's an 'ultrasonic' fingerprint sensor
The 3D Sonic Sensor fingerprint sensor developed by Qualcomm uses sound waves (this is the "sonic" part) to "read" your fingerprint when you unlock your phone. The trend is to embed this fingerprint sensor underneath the display so you can unlock the phone by putting your finger or thumb in the center of the screen – it's also called an in-screen fingerprint reader – but this type of sensor could also exist on a device's home button. CNET saw a prototype of this ultrasonic sensor in 2015.
In this case, the ultrasonic sensor is integrated into one of the several layers that make up your phone's display. When you put your finger on the target area, you're touching the glass that is topping your phone, not the sensor. But your skin does send out a tiny electrical pulse that activates the sensor and gets it to do its thing.
How does the ultrasonic sensor work
When your electrical signal hits the sensor, it emits sound waves that bounce back to your skin. Your skin's surface is not flat – your fingertip is a unique pattern of ridges and valleys, which is what makes fingerprinting a useful form of identification. These ultrasonic waves bounce back to the processor, which maps your fingerprint based on the pressure reading of the sound wave bouncing off your skin.
In a simplified example, say that your ridges are a 1 and your valley is a 0. The ultrasonic sensor module can map out that data to form a detail -rapid 3D image of your fingerprint. The soundwaves can also detect your blood flow, and would reject a print from a severed finger.
An optical fingerprint reader – like the one powered by component-maker Synaptics that– Bounces light to your finger and back to the sensor, which interprets the reading as a 2D image. It essentially takes a photo of your finger to determine the pattern of ridges and valleys. But experts say this approach is easier to fool with a photo, a fingerprint transfer (for example, if someone has lifted your print) or a prosthetic fingerprint
Qualcomm claims that its ultrasonic fingerprint sensor is powerful enough to get a reading of 4 millimeters when it scans your print. That's a pore level. We have not tried the Galaxy S10's ultrasonic fingerprint reader yet, so we can not say for sure if that's right.
How is a fingerprint reader with a fingerprint reader?
When you put your finger on a smooth reader on the back, side or home button, your fingerprint is captured by a capacitive fingerprint reader. Yes, "capacitive" is the same term that applies to your phone's touchscreen, where your finger lets off trace amounts of electric charge to the display to sense where you are touching
It's the same case here. Capacitors across the scanner detect the placement of your finger ridges by measuring the electrical charge and then matching the pattern of those charges to your registered fingers
Apple's Face ID uses a depth map of 30,000 infrared dots to map your facial contours. Samsung used to use competing technology to scan your irises, but has removed that for the new phones. The Galaxy S10 phones use a third method that's baked in Google Android, which basically takes a photo of your face. Face ID and iris scanning are considered secure enough to use for mobile payments, but the facial-recognition option In Android Pie will not support mobile payments. It's there for convenience, but it will not give you strong protection.
It is possible that Samsung has run into difficulty getting a face-facing 3D face scanner to work in time for its Galaxy S10 launch. It's also possible that Samsung is tying its fate to whatever Google supports, in order to save money on an investment that could be just a few months away. It would not be entirely out of bounds to think that Samsung wanted to save a Face ID-style option for an August release of Galaxy Note 10.
Whatever the plan, whatever the motivation, it is likely that the ultrasonic in- screen fingerprint reader will stick around for several generations – especially if it proves to be as fast, convenient and secure as Qualcomm says.
Published: Dec. 4, 2018.
Update : Feb. 21, 2019 at 10:01 AM PT