Xiaomi Mi Mix 4’s CUP (Camera Under Panel) Full Screen Technology: How does it Work?

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 that 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 when we come to 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. And this year, the Mi Mix 4 features CUP (Camera Under Panel) technology, which is certainly 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 once 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 in such a way that light will pass through the display and reach the camera, allowing photos to be taken. The OLED Panels have their own transparency, which also allows 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 so that it creates a gap between each pixel in the area where the camera is located. The whole process just 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 gets 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.