In June, Xiaomi showed its own smartphone with a camera under the display surface (prototype Mi 9 without a notch or punch-hole display). It was rumored that a similar approach would be used in Xiaomi Mi Mix 4. However, instead of it, we got a Xiaomi Mi Mix Alpha conceptual device wrapped in a screen for $2800. However, it is claimed that the Mi Mix 4 is still in operation, and a recently discovered patent describes one of its functions.
A patent entitled “Display Structure and Electronic Equipment” describes a hidden camera under the smartphone screen that does not require a notch or punch-hole design which are mainstream to the current smartphones in the market. The patent shows that the structure of such a display in the camera area includes a light adjustment unit located in the light-emitting part of the display.
This area of the screen works in polarization mode when it completely hides the cameras. The pixels above it are turned off to also transmit light. The patent describes to independently control such areas.
Recently, the Chinese company Oppo also showed a similar technology that hides the front camera under the display. So far, the main drawback of this approach (it is difficult to achieve ideal transparency) is the relatively low photosensitivity and, consequently, poor quality of images, which manufacturers want to compensate with machine learning algorithms.
Perhaps Xiaomi has made significant progress in this area, and in the coming months, it could introduce a commercial smartphone with a hidden front camera. It is rumored that Mi Mix 4 could be launched in CES 2020 or MWC 2020.