As some of you may know, the under-screen fingerprint readers that we have seen on the market in recent years are not compatible with all types of displays. In fact, these sensors only work with AMOLED screens and this thanks to the lack of backlighting that we have on the LCD panels instead.
Redmi: New fingerprint sensor under LCD display is coming soon
Well, today the vice president of Xiaomi Group and general manager of Redmi, Lu Weibing, announced on Weibo (the Chinese Twitter), that the Redmi brand has finally managed to implement sensor technology under LCD-type screens.
At the same time, Weibing also released a demo video of a prototype based on the Redmi Note 8. In the video we see the smartphone successfully unlocked thanks to a sensor under the screen and with excellent speed.
Lu Weibing then revealed some details on the technologies available today. Explaining that the principle is to record the characteristics of the fingerprint on the screen and then pass them on to the sensor below. Since the sensor is below the screen, optical or ultra sound technology must be used to transmit the signal. This technology works only on OLED displays as the LCD ones have, as we said previously, a module for the backlight.
At the moment, devices with LCD screens, even of a medium-high range, have been forced to use fingerprint sensors on the back or on the sides, such as on the latest Redmi K30. According to Lu Weibing, however, Redmi's research and development team managed to get around the problem with a sensor that works through LCD screens. The sensor would also be ready to go into mass production.
How does all this happen? Thanks to a very innovative high transmissibility infrared technology that greatly improves the amount of infrared light that passes through the screen. So we have the infrared emitter under the screen that emits a beam of light that is then reflected by the fingerprint, going back through the screen and allowing recognition.
Now it is not clear to us why Redmi decided to spend time and money to create an alternative technology when perhaps it would have been cheaper to use an OLED panel, at least on the Redmi "K" series. Having said that, if the new technology goes down in price, it could become an excellent option for all those medium-low end devices for which an OLED panel would become too expensive. We speak for example of the Redmi Note series and why not, also the basic Redmi one (Redmi 8 etc ..).
