Research And Implementation Of OLED Optical Compensation Algorithm Based On CCD Image

Organic Light Emitting Diode(OLED)has the advantages of flatness,active light,high brightness,wide viewing angle and fast response.With the development direction of large size,light weight,low power consumption,high-resolution,the probability of defects in OLED display is greatly increased.Due to the low contrast of the Mura(Japanese,original stain or stain)itself,there is no clear edge and the whole screen brightness shows a great non-uniformity.The traditional detection methods by human eyes are affected by subjective psychological factors and other external environment,so that the method of manual testing is difficult to meet the requirements of product quality and production efficiency.To carry out various types of OLED display defect detection and compensation for OLED,the significance is that to find the OLED display surface defects meanwhile repair them in order to improve the life of OLED screen.The overall compensation program mainly includes two parts of OLED luminous uniformity measurement and external drive current adjustment.Specifically,the light intensity information of the self-luminous point of the OLED is received by the light-sensitive surface of the high-resolution CCD camera and converted into the corresponding luminous intensity value of the screen.Compared with the standard brightness data of the corresponding gray level,the adjustment of the input analog signal of the sub-pixel is calculated.The signal generator is used to drive the compensation module to adjust the input signal.Aiming at the problem of the accuracy of optical measurement in the external optical compensation of OLED display,this dissertation introduces the algorithm of pixel location and brightness extraction.In view of the characteristics of independent display of OLED pixels,the structure of image processing algorithm is designed to obtain a series of image preprocessing algorithms including pixel brightness of display screen and planar field correction.The threshold method is used to realize image binaryzation.Then the morphological cornea swelling method is used to get the center of the pixel,and then the original vector recursion method is used to accurately locate all the pixels.Compared with the existing methods,the proposed imaging positioning algorithm can be accurate to the sub-pixel level,and ultimately improve the compensation effect for improving the display uniformity of the OLED screen.According to the luminescence regularity of Gamma linearity of OLED pixels,a polynomial model of brightness-grayscale relation was proposed,which solves the problem of low fitting efficiency and slow algorithm adaptively.According to the characteristics of human visual system,Human eye visual assessment of the law,to achieve the assessment of uniformity before and after compensation.