Fingerprint sensors on a smartphone, for most of us, conjures up the image of a circular ring at the back panel or home buttons which double up as biometric authenticators. At the MWC 2017 Shanghai event, Vivo added a new dimension to the whole concept – displays that double up as fingerprint sensors.
Essentially, a future where there will be true edge-to-edge screens as authentication technology will be through independent ‘regions’ and technically anywhere on the surface of the smartphone. Confused? Here’s an explainer on the Vivo under-display fingerprint scanning technology.
What is it?
The Vivo under-display fingerprint technology is based on Qualcomm’s ultrasonic fingerprint sensors. It eliminates the need for manufacturers to place a dedicated sensor on a smartphone as it injects the ability to unlock or authenticate from underneath the surface of the phone. The new type of authentication is supported for surfaces including OLED screen, metal frame, specific kind of plastic and ceramic. ALSO READ: MWC Shanghai 2017: Vivo’s new technology aims at making fingerprint sensors invisible
How does it work?
The solution provided by Vivo uses an ultrasonic sensor underneath a surface (display or rear panel). For authentication, piezoelectric effects (in simple terms, the mechanical stress or the pressure put on the surface) are used to exchange ultrasonic signals which travel through the OLED screen.
Once the ultrasonic signals travel through the OLED screen, they create a 3D map of the fingerprint under the display. Consider this as a sound wave traveling through compatible surfaces and creating unique fingerprint-based identities with the help of software. At the event, Vivo showcased a prototype device exploiting the technology. By putting mechanical stress or pressure on a designated area of the display, the fingerprints are registered and authentication is carried out. ALSO READ: Vivo under-display first impressions: Biometric authentication just took a bold step
As for the end-user, the whole process merely takes a slight shift in terms of positioning. Instead of strategizing or finding the right way of placing your finger or thumb on the sensor, the potential usage of the Vivo under-display pictures a situation where the screen-to-body ratio can be increased. Currently, the highest ratio is just above the figure of 90 percent, as seen on the Xiaomi Mi MIX smartphone. However, even that smartphone features a dedicated sensor at the back. ALSO READ: MWC Shanghai 2017: Qualcomm announces Snapdragon Wear 1200 for low-end wearables
It is also worth noting that the Vivo under-display technology is said to work with metal, OLED display, and also certain type of plastic. It can not only be embedded under the display but also behind the metal shell or even in the frame, as Vivo suggests.
How is it different from traditional sensors?
The technology teased by Qualcomm could only penetrate 400μm of glass and capacitive scanners only go up to 300μm. However, the Vivo under-display improves on the sensing capabilities and as it can penetrate 1.3mm of OLED, 525μm of aluminum or 800μm of glass.
With capacitive sensors, the water-resistant capabilities is amiss. If you have soiled or wet fingers, a capacitive sensor fails to scan your finger impression. Similarly, instances where a smartphone is otherwise claimed to be water resistant, the fingerprint sensing fails to work under water. ALSO READ: Qualcomm Snapdragon 450 platform announced at MWC Shanghai 2017
In contrast, the Vivo Under Display is claimed to be waterproof, dustproof, and sweat proof, something we witnessed at the experience zone. It is also worth mentioning that capacitive sensors as seen on the Apple iPhone line-up, recognizes the finger impression through electronic signals and does not support OLED screen or metal surface, whereas the ultrasonic sensors use ultrasonic waves for fingerprint identification and support OLED screen, metal and allow underwater usage.
What’s the future?
It is to be understood that the Vivo under-display technology is currently a proof of concept and not a fully baked product. However, the company pictures future applications where fingerprint scanning is not carried by a dedicated button, but in a more subtle fashion by layering it underneath the display, behind the metal shell, or even in the frame.
As the technology is claimed to have better waterproofing and anti-ambient light feature, the future usage also includes a full edge-to-edge display along with a waterproof design. It can also be enhanced by software tweaks which allow gesture recognition, security verification, and more. So, if you draw a pattern on the display on your smartphone currently, Vivo’s technology sees a potential use where you could perhaps authenticate through fingerprint-based patterns drawn on the display.
Disclaimer – Vivo sponsored the correspondent’s flight and hotel accommodation for MWC 2017 Shanghai event.