High-precision color uniformity based on 4D transformation for micro-LED

Micro-LEDs are expected to bring revolution to display technology with its high brightness, long lifetime, refined performance and low power consumption. However, the electroluminescence spectrum of a Micro-LED varies significantly depending on the driving voltage and current, and thus ensuring the uniformity in red, green, blue colors in terms of the chromaticity and luminance across a massive amount of pixels is challenging for mass production. Due to its micron-level size, color correction by mechanical treatments is limited in practice. In order to overcome this bottleneck in the development and commercialization of Micro-LED technology, we propose a 4D transformation algorithm which allows to efficiently adjust non-linear chromaticity and luminance of Micro-LEDs and acquire the true color characteristics with high precision. We evaluate the performance of our algorithm with measurements and verify its outstanding performance compared to the conventional algorithms. The standard deviation of proposed uniformity correction result is about 2% and the color and luminance uniformity ΔE is below 3.5.