For several years, in smartphones from various price shelves, manufacturers have been using an under-screen fingerprint reader, which has both advantages and disadvantages. Xiaomi has developed a patent to get rid of one of the disadvantages of such a solution.
In the patent, Xiaomi demonstrates the principle of technology: under the capacitive touch screen and above the usual AMOLED display will be an array of infrared LED emitters. The array of infrared light receivers will be located above the infrared LED emitters. All of the above emitters and receivers are essential components of a full-screen fingerprint scanner.
First, when the user wants to scan a fingerprint on the screen, he touches the screen with his finger, the capacitive touch screen registers the touch, position, and shape of the fingertip, then an array of infrared LED emitters emits light on the screen only according to the shape and position of the fingertip. Note that the surrounding LED emitters do not flash in this case.
Next, after contact with the fingertip, infrared light is reflected and hits the IR light receiver. The infrared light speed data will be used to map the fingerprint outline, and then compared to the saved fingerprint data to verify that it matches the saved user. If so, the user will be able to unlock their smartphone from anywhere on the screen.
Huawei actually submitted the patent for their own fingerprint technology in six countries, including China, Europe, the United States, Japan, Korea, and India, in August 2020.
However, Huawei has not yet introduced smart gadgets with that technology. Now that Xiaomi has jumped on the bandwagon, we can hope that smartphones with this technology will soon shine in the tech market. At this stage, this is only a patent and nothing is said when the technology will find its commercial embodiment.