Xiaomi recently launched its Mi Mix 4 smartphone in China. It was the first device in the Mi series to come with an under-display selfie camera. However, it’s worth mentioning that the Mi Mix 4 uses a pretty different implementation of the under-display camera in the market. The company also claims it took them two years and a total investment of 500 million Yuan to develop this product. Isn’t it a little too interesting? They call this CUP (Camera Under Panel) technology. Let’s find out how the CUP technology on the latest Mi Mix 4 works.
Mi Mix 4’s CUP Full-Screen Technology
The Mi MIX series of smartphones has already come up with a new bunch of innovations. The first Mi Mix plays a major role in full-screen displays, from cutout displays to warp around the display in Mi Mix Alpha. Each of them brings a new set of improvements and innovations. This year, the Mi Mix 4 features CUP (Camera Under Panel) technology, which is not new to the market but is implemented uniquely. While we all want to know more about the technology behind it, the firm has officially published an article introducing the Mi Mix 4 smartphone’s CUP technology.
Xiaomi released its transparent TV in China back in 2020. The TV was able to give you a real-time transparent effect by rearranging the pixels and optimizing the substrate material. The Mi Mix 4 utilizes comparable technologies and operates on the same principle. The pixels organize themselves so that light will pass through the display and reach the camera, allowing photos to be taken. The OLED Panels have their own transparency, allowing the under-display fingerprint scanners to work. But this amount of transparency isn’t enough for the selfie camera to grab the lights clearly.
In solution to this, the Mi Mix 4 moves the TFT circuitry below the screen pixels. They get arranged to create a gap between each pixel in the area where the camera is located. The whole process takes some milliseconds to get completed. Later on, the camera gets a sufficient amount of space to capture the light. Going deeper, the individual sub-pixels get accordingly so that the gap between each pixel gets enlarged. After that, the pixels’ lead circuits are replaced with Indium Tin Oxide (ITO), a transparent wire that boosts light transmission even more. The alignment path was also altered to a wavy shape to prevent diffraction. So that’s how the Mi Mix 4’s CUP (Camera Under Panel) technology works.
Compared to standard flexible OLED panels, the display achieves 5X greater transparency after the entire process. Even though it isn’t completely transparent, the company uses a software technique to compensate for the lower amount of incoming light and image quality. Not only that, but there are a lot of things that happen behind the scenes and in the software.