Coming to the patent that was filed on November 7, 2018 and got approved on May, 31st, 2019, it shows that the phone has a secondary display under the main display on top of the camera. The light sensor works with both screens so that the camera will be visible or invisible when needed offering a true full-screen experience. Since the movement of the second display and the light sensor are completed under the first display, the aesthetics and the operation convenience of the smartphone during use are improved, says the patent.
Explaining this, Xiaomi says:
How do you get a Full Screen Display without the need for a slider or pop-up camera? Xiaomi is currently exploring the possibility of hiding the front-facing camera under the display. When the selfie camera is activated, the display area over the camera lens becomes transparent in an instant, allowing light to enter. This could be the ultimate solution for a Full Screen Display coexisting with a front camera.
Comprising technologies that have been developed in-house, the all-new custom display features a small area with a transparent display, which is made using a special low-reflective glass with high transmittance. When not in camera mode, the transparent display works like a normal one, allowing your content to be shown in full.
Unique screen-lens integration Forever enclinn the notch-era
The front-facing 20MP camera is hidden under the display, with a cleverly designed display-embedded camera combo — the transparent display doubles as the camera lens. By allowing more light into the lens, the display-embedded camera combo is able to produce perfect selfies, clearer and crisper than the pinhole camera solution when the camera is activated. When the display is turned off, the front camera disappears and results in a black surface that is completely seamless.
OPPO
Even OPPO has posted a video showing off its under-display camera on its smartphone wrapped in a case. The company did not share any other details about it.
Samsung
At the 2018 Samsung OLED Forum in October, Samsung was the first company to announce that it is working on smartphones with under-screen sensor technology, including camera. Last month Samsung Mobile’s vice president of the display R&D group, Yang Byung-Duk has confirmed the same to Korean media.