Fingerprint sensors under the screen: how does it work?

A smartphone is never secure enough for most people. Numerical code, pattern, password of any kind seem not to be enough for an optimal locking of the Smartphone. In this age of technological evolution, smartphone locking can be done using fingerprinting, iris scanning or even facial recognition for some high-end smartphones.

There are two types of screen locking via fingerprint. In an evolutionary way, there was the traditional sensor. Then there is the appearance of the fingerprint reader integrated into the screen of the smartphone itself.

From the traditional sensor to the fingerprint reader on the screen

The evolution of the screen unlocking mode from a traditional sensor to the on-screen fingerprint reader is due to the new specifications of the smartphone screen. Indeed, on newer smartphone models, the screen covers almost the entire surface of the phone.

With this screen filling, unlocking the phone becomes a challenge for manufacturers, since other features have to be integrated into the smartphone. Not to mention that when it leaves the factory, the phone needs to be thinner and lighter. The solution adopted was to integrate the fingerprint reader under the smartphone’s screen.

Is the screen lock with the fingerprint really effective?

Instead of wasting time entering your password, unlocking the smartphone with the fingerprint screen lock mechanism saves time and makes the phone easier to operate.

However, with a thinner screen, i.e. one that is easier to break, it is strongly recommended to protect the screen to prevent breakage. A broken screen prevents proper fingerprint recognition.

How does the unlocking with the fingerprint reader on screen work?

The screen unlocking system is placed on a specific part of the screen to ensure that the smartphone is unlocked. The screen in question must be Amoled or Oled, since this type of screen emits its own backlight. This is an important condition to enable the optical sensor to detect any wrinkles in the owner’s finger. In addition, it is advisable to place the finger gently on the exact part of the screen.

Fingerprint enrollment takes place in the same way as with a traditional fingerprint sensor. The sensor stores the fingerprint by emitting a small light that is reflected from the finger and transmitted back to the sensor.