Uncertainty analysis and specification design of spectroscopic imaging colorimeter for Micro-LED display

Abstract

The Micro LED display technology overcomes various shortcomings of the widely used display, and achieves high brightness, high resolution, long lifetime and low power consumption at the same time. In order to control the product quality of Micro LED display, manufacturers generally use chromaticity and brightness measuring instruments to measure the luminous characteristics of sub-pixels. Traditional single-point spectroradiometric colorimeter has low measurement efficiency, and the imaging colorimeter based on tristimulus filters needs chromaticity correction. Compared with them, the spectroscopic imaging colorimeter proposed in this paper characterizes both high speed and accuracy due to concurrent imaging and dispersion. To develop a spectroscopic imaging colorimeter which can meet the performance requirements, this paper analyzed the uncertainty of the sub-pixel chromaticity and brightness measurement of Micro LED display screen, and designed several key specifications based on this. In addition, through the establishment of an analytical model, the variation of the input radiation source subjected to various uncertainty components during the process from radiometric calibration to target measurement are simulated, and to predict the chromaticity and brightness uncertainty under the designed specifications. The results show that for blue, green, red LED light sources and standard illuminant A, under the designed specifications, the uncertainty of chromaticity measurement is about 0.001, and the uncertainty of relative brightness is about 3% and 1%, respectively.