Although in-display fingerprint recognition systems have been actively used in Android smartphones since at least 2018, the technology has not developed much lately, but Xiaomi has not presented its own solution. It allows you to touch any part of the gadget screen with your finger to identify the user.
According to the latest information from the Chinese Patent Office, the company has received a patent for a fingerprint scanning technology that allows you to use the scanner more freely without having to place your finger on a specific part of the screen. In the patent, Xiaomi described the operation of a network of integrated infrared LED elements that are located between an AMOLED display and a capacitive touch layer. The network of “receivers” is integrated into the display. These elements form the basic building blocks of the new scanner.
When the user touches the screen with a finger, the touch layer registers the touch, its position and the shape of the fingerprint, whereupon the LED elements start to emit infrared light in the desired area. In this case, items in other parts of the screen remain inactive.
The infrared light is then reflected from the fingertip and projected onto the receiver. The received data is processed to obtain a “map” of the fingerprint and the smartphone compares it to the pattern stored in memory – the user can unlock the device by touching any part of the screen.
Back in August, Huawei patented its own technology for a similar purpose in several markets including China, Europe, US, Japan, Korea, and India, but the development has not found commercial application – possibly due to US sanctions on technological capabilities of the company. Since such sanctions have not yet been imposed on Xiaomi, it is possible that new scanners will come onto the market in the foreseeable future.