It seems Oppo is not the only one coming with an under-display camera phone. Xiaomi has also tweeted a short video showing a phone with an under-display camera.
In the video, you can see two phones where the phone with left side has no notch. While opening the camera app in selfie mode, there is no pop-up camera either. The selfie camera is under the display.
Also see: Oppo Teases An Under-display Camera
Xiaomi also gave more details about this tech on Weibo post. It explains that it has patented a way to make the display transparent without reflecting light in any way when the screen is black and diodes are off. Xiaomi claims that it can add a 20 megapixels camera with the 5P lens under the panel.
Xiaomi has not revealed any launch date of a phone using this tech. In the past, the company has used Mix series for launching this kind of experimental tech. So, I hope the next Mix series phone should get this tech.