Position Calibration and Pixel Correction for Uneven Brightness Micro LED Display

Abstract

Due to process deviations (Devs) in Micro LEDs, the luminous efficiency of each individual Micro LED can differ. Consequently, this leads to uneven luminance across the Micro LED matrix panel. In this study, a correction algorithm is proposed with the aim of improving luminance inhomogeneity on the panel. The brightness value of each pixel point on the LED panel is measured using a camera. Since the panel’s position may shift during detection, our approach incorporates self-detection and position correction to handle such misalignments. This eliminates the need for manually aligning the LED module to a fixed position on mechanical fixtures in our calibration system. The embedded system uses a camera to detect panel brightness and then generates correction coefficients for individual LED. Afterward, the coefficients are loaded into the FPGA control board and stored in memory as a Look-Up Table (LUT). Pixel correction on the Micro LED panel is achieved by selecting the corresponding coefficient from the LUT for each pixel position. The same procedures are iteratively performed ~3–4 times, using recursive processing to achieve superior uniformity across the Micro LED panel.