In-display fingerprint sensors are pretty cool. They do away with the need for a dedicated fingerprint sensor, and it could potentially lead to a future where we have phones that do not have ports or buttons. The main issue right now is that these in-display sensors require users to place their finger/thumb on a specific part of the display
This means that if you’re out of the area slightly, your fingerprint won’t register. Xiaomi thinks that the best solution to this problem would be to simply make the entire display capable of reading the fingerprint to begin with. This is according to a patent that was recently awarded to the company as discovered by GizChina.
According to the patent, it suggests that Xiaomi wants to make the entire display a fingerprint sensor. How this works is that there will be an array of infrared LED light transmitters placed beneath the touchscreen layer. So what happens is when the user places their finger on the screen, based on the position and shape, only the infrared LEDs in that area light up to scan for the fingerprint to authenticate the user.
Xiaomi is actually not the first to come up with the idea. Prior to this, Huawei had also patented their own idea of an all-display fingerprint sensor, but to date we have yet to see it make its way into any of the company’s phones.