How many types of fingerprint sensor under the screen? Which type of

Even though it is located in a more convenient position, the slower identification than the conventional capacitive fingerprint sensor has made the fingerprint sensor types under the screen unpopular.

Recently, the trend of designing smartphones with user-friendly overflow screens has paved the way for new sensor technologies. However, this design also entails a trade-off of the feature: the fingerprint sensor on the front of the machine is forced to move to another location.

While the popular choice of Android brands is on the back or side of the device (like Sony), some technological advances have brought the fingerprint sensor back to the front of the device. But here, users seem to be lost in a different terminology about these new technologies: fingerprint sensor "under the screen" and "under the glass" , in addition to fingerprint sensors "in the screen". picture " ?

A common fingerprint sensor.

So what are these different technologies?

Basically, the above terms indicate the difference in the location of the new fingerprint scanning sensor, as they are now scaled to the point where they can be placed under the touch screen or protective glass. Touch screen without affecting the operation of these parts.

Let's start with the difference between the fingerprint sensor inside and below the screen . The first smartphones and concept devices with integrated fingerprint sensors under the screen or under the glass, as illustrated in the following two pictures, were introduced to the market earlier this year.

For example, Huawei recently launched the Honor 10 with ultrasonic sensors under the glass and earlier this year, Vivo introduced the X20 Plus with a fingerprint sensor placed under the screen. These solutions will bring a better user experience and lower production costs as they can be placed right on the screen of smartphones with borderline design, without having to cut off part of the screen space. for it.

However, by using optical sensors under the screen or under the glass to identify fingerprints, the speed of fingerprint recognition is significantly slower than conventional fingerprint readers, which use sensors. capacitance. This may be the reason why Samsung refused to equip these fingerprint sensors for their flagships, such as Samsung Galaxy S9 and S9 Plus.

Fingerprint sensor based on Synaptic's CMOS optical chip.

Another reason that limits the popularity of the fingerprint sensor is the cost of introducing it into the smartphone screen. To put optical fingerprint sensors into smartphones, monitors need to use OLED panels, which are very expensive - often equipped with flagships rather than mid-range devices (Oppo is planning to launch the device). Mid-range equipped with this type of fingerprint sensor in the future). Meanwhile, the experience it brings doesn't really suit that device's price.

Why is this technology so far not popular?

Qualcomm also has its own fingerprint sensor technology, which uses ultrasound instead of optics - promising to work more accurately. However, it is very difficult to manufacture and also has a significantly higher price. So far, the Honor 10 is equipped with this sensor, but it is placed outside the screen, instead of under the screen like the Vivo X20 Plus.

Qualcomm's ultrasonic fingerprint sensor on the Honor 10.

Toward the future

However, we are aiming for solutions with fully integrated "in-screen " sensors, as illustrated in the third image. According to HIS Markit analyst Jamie Fox, this is also what we expect to see in the next few years. Developing sensor solutions in the screen is motivated from the mobile industry's desire for a more efficient production process, along with improved user experience and security.

If it is possible to place the fingerprint sensor anywhere on the mobile screen, it will bring considerably more convenience than having to find the right place to place your finger on the screen. Fingerprint sensors in the screen will cover most or all of the screen, furthermore it provides a larger image scanner.

Therefore, it will bring better biometric performance, and allow two-finger or more authentication at the same time. This will add another layer of security, to be used for sensitive mobile applications or to make payments.

In addition, considering that we are using mobile devices several times a day, the larger sensor solution can support continuous authentication when the user is authenticated. Hold on to the screen, regardless of location).

This will be desirable when the phone is becoming a personal authentication device, when we can do most of our personal things: from banking transactions to accessing sensitive documents. feel.