Redmi Showcases Under-Display Fingerprint Sensor That Works With LCD Screen

In recent years, we have been coming across several smartphones, especially premium mid-range and high-end models feature under-display fingerprint sensors. The trend debuted with Vivo that was the first smartphone maker to unveil a smartphone with such a sensor - the Vivo X20 Plus UD, which went official back in early 2018.

Since then, the in-display fingerprint sensor has been widely adopted by almost all companies. However, the downside that is faced by some manufacturers is that this tech cannot be used with LCD displays due to the structure of the panel. Now, it looks like Redmi has managed to find out a breakthrough in this aspect.

Redmi Showcases Under-Display Fingerprint Sensor

In a recent development, the Redmi brand manager Lu Weibing shared a Weibo post confirming that the company is working on implementing a fingerprint sensor positioned under an LCD panel. The executive also showcased how the tech will work on a Redmi Note 8 Pro prototype.

The working principle of the under-display fingerprint sensor is to record the characteristics of the fingerprint and feed the same to the sensor positioned under the screen. And, it determines if the same coincides with the registered fingerprint. The limitation is that the LCD screens cannot feature this visible unlocking method due to the backlight module.

The major challenge in implementing an under-display fingerprint sensor with LCD screens is the backlight module that will interfere with the optical fingerprint sensor. Interestingly, the R&D department of Redmi seems to have managed to overcome the issue and appears to be working on pushing the breakthrough in the feature towards mass production.

In the innovative method, Redmi uses infrared high-transmittance material, which greatly enhances the transmittance of infrared light. The transmitter at the bottom of the display emits infrared light. Once the fingerprint is reflected, it will penetrate the display and shine on the fingerprint sensor to complete the verification. Thereby, the fingerprint sensor issue with LCD displays.