Research On Luminance And Chroma Detection Method And System For Flat Panel Display Pixel

In recent years,the manufacturing technology of flat panel display has developed rapidly.Mini LED and Micro LED display have become the focus of research.The measurement of pixel luminance and chroma distribution plays an important role in process improvement and product quality control.In this thesis,the measurement method and system of pixel luminance and chroma performance of flat panel display are studied.This thesis describes the related principles including the optical principle of microscopic imaging luminance meter,tristimulus values direct reading method,color filter matching principle and method,screen pixel machine vision detection algorithm and so on.The thesis designed a kind of microscopic imaging luminance meter and proposed its calibration method.A kind of three dimensional motion detection platform equipped with the micro-imaging luminance meter is designed.The flat panel display pixel luminance and chroma detection method suitable for this system is proposed.In this thesis,a low-cost prototype is built to verify the principle and detection method of the system by using a macro lens with a close-up lens and increasing the image distance instead of a high-magnification microscopic lens.The prototype was calibrated using the integrating sphere standard A light source which has more than 98% isotropic uniformity and known luminance and chroma.The test results of the prototype have good repeatability under different luminance of light source.By measuring different luminance and color of the 95% isotropic uniformity LED surface light source,the test results achieve luminance and chroma measurement accuracy and repeatability requirements,the measurement results meet the expectation.The OLED mobile phone screen and Micro LED micro-display are measured,and the functions of automatic measurement of white field,analysis of luminance and chroma uniformity between the same kind of sub-pixels,analysis of luminance chromaticity uniformity within the sub-pixel,and display of luminance and chroma distribution pseudo-color map are realized.The results show that the principle of the pixel light color performance detection method described in this thesis is feasible.By increasing the Signal to noise ratio and sensitivity of the CCD sensor,further improving the magnification of the imaging lens,using the lens with small aberration and large depth of field,optimizing the matching accuracy of the filter,the system can meet the measurement requirements of the pixel luminance and chroma of all kinds of flat panel display.