Fingerprint sensor in mobile screen.

Fingerprint sensor in mobile screen

In fact, the fingerprint sensor made by sensor company Synaptics lives beneath the 6-inch OLED display. That's the "screen" you're actually looking at beneath the cover glass. You can see it in our photos here. 

Fingerprint sensor in mobile screen

When your fingertip hits the target, the sensor array turns on the display to light your finger, and only your finger. The image of your print makes its way to an optical image sensor beneath the display. It's then run through an AI processor that's trained to recognize 300 different characteristics of your digit, like how close the ridges of your fingers are. It's a different kind of technology than what most readers use in today's phones.  

Synaptics, which demoed the Vivo phone in a crowded booth at the back of an interminable hallway, says that the fingerprint reader won't suck up much more battery by illuminating your finger, promising that its power management is equal to industry standards.

Because the new technology costs more to make, it'll hit premium phones first before eventually making its way down the spectrum as the parts become more plentiful and cheaper to make.  

Fingerprint sensor in mobile screen

Will Samsung put a fingerprint sensor within the Galaxy Note 9 display? That's been a topic of debate for weeks now as arguments both support and contradict the rumor. "Samsung Display has prepared three or four solutions for Samsung Electronics to embed the fingerprint sensor inside of the main display, and both are seriously considering one of the solutions," The Investor reported.  

As of now, Chinese company Vivo is the only company that has embedded a fingerprint sensor into a phone's display. This means you can unlock the phone by pressing your finger on the screen, without the need for a physical scanner on the bezels or back of the phone.

Samsung had been rumored to be including this feature in its phones starting with the Galaxy S8, but that never happened. Instead, Samsung included a physical fingerprint scanner on the back of the S8, irritatingly close to the phone's camera. Having an embedded sensor would solve this problem by getting rid of the scanner altogether. 

Synaptics’ first partner for the Clear ID sensor is Vivo, and the company brought its unannounced phone packing the new technology to CES 2018. In our hands-on demo of the product, the functionality was pretty much flawless. While this sensor is definitely a lot slower than a good capacitive sensor, Clear ID is just as accurate. A Synaptics representative even mentioned that this type of sensor is more accurate than a capacitive sensor when it comes to things such as wet hands.

Fingerprint sensor in mobile screen

Fingerprint Scanners

There are four types of fingerprint scanners: the optical scanner, the capacitance scanner, the 'ultrasonic scanner' and the thermal scanners. The basic function of these three types of scanners is to get an image of a person’s fingerprint and find a match for this print in the database. The capacitance scanner is better, because the images are more exact and precise. Scanners are used for scanning.

1) Optical scanners take a visual image of the fingerprint using a digital camera.

2) Thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys.

3) Capacitive or CMOS scanners use capacitors and thus electrical current to form an image of the fingerprint.
The most commonly found type of fingerprint scanner used today is the capacitive scanner. You’ll find these type of scanner inside various flagships, including the Galaxy S8, HTC U11, LG G6, and others. Again the name gives away the core component, providing you’re familiar with a little electronics, the capacitor.

Instead of creating a traditional image of a fingerprint, capacitive fingerprint scanners use arrays tiny capacitor circuits to collect data about a fingerprint. As capacitors can store electrical charge, connecting them up to conductive plates on the surface of the scanner allows them to be used to track the details of a fingerprint. The charge stored in the capacitor will be changed slightly when a finger’s ridge is placed over the conductive plates, while an air gap will leave the charge at the capacitor relatively unchanged. An op-amp integrator circuit is used to track these changes, which can then be recorded by an analogue-to-digital converter.

4) Ultrasound fingerprint scanners use high frequency sound waves to penetrate the epidermal layer of the skin.

Fingerprint sensor in mobile screen

Construction forms

There are two construction forms: the moving fingerprint scanner and the stagnant scanner

Stagnant: The finger must be dragged over the small scanning area. This is cheaper and less reliable than the moving form. The image is not very good when the finger is not regularly dragged over the scanning area.

Moving: The finger lies on the scanning area, while the scanner runs underneath. Because the scanner runs regularly over the fingerprint, the images are better.Fingerprint sensor in mobile screen

How fingerprint scanners work:

Fingerprint scanners aren’t just reserved for the very top-tier of smartphones these days, even your reasonably priced mid-ranger can come packing in the additional security hardware. Heck, even a number of sub-$150 devices these days coming packing the technology. Technology has moved on a lot from the early days too, becoming faster and more accurate in their readings.

When you hold up the phone, the fingerprint sensor indicator will light up, meaning that you can now unlock your smartphone using this part of the biometrics. According to videos seen online, it is definitely slower than regular fingerprint readers so improved iterations of the scanner will have to be introduced to make it faster. This is possibly the reason why Samsung might have refused to incorporate this sensor on the Galaxy S9 and Galaxy S9 Plus.

What Are the Possibilities of the in-Display Fingerprint Scanner for Future Smartphones?

As we said before, the sensor does not have to be placed at a single location. During the announcement of the Vivo APEX, which is honestly the first glimpse into the future of what bezel-less smartphones will look like, it too features an in-glass fingerprint reader, but here’s the catch.

The bottom half of the phone is covered by this CMOS sensor, which the company is calling it the ‘Half-Screen Fingerprint Scanning Technology’. This means that you place your finger anywhere at the bottom half and if your fingerprint is registered, the phone will unlock seamlessly.

This development also means that there is a future where we might get to see smartphones with their entire displays being covered with the sensor.

All you will have to do is whip it out, place your finger anywhere and immediately, the phone will be unlocked. That is certainly a future that we will look forward to witnessing but for that specific future to materialize and become a reality, better versions of the fingerprint are going to have to be released.