Design And Implemention Of AMOLED Luminance External Compensation System

Compared with traditional LCD display technology,AMOLED has gradually developed into the mainstream flat panel display technology because of its superior display characteristics.With unique technical advantages such as flexibility,lightness and thinness,AMOLED display products have been widely used in applications such as mobile phones,wearable devices,TVs and other fields.With the increasing demands of consumers on the high quality of display images,the problem of non-uniform luminance of AMOLED displays has become an urgent problem for panel manufacturers.Therefore,studying and designing a compensation system for improving the display quality will help solve the problem of increasing the yield rate faced by panel manufacturers,and also help accelerating the development of the AMOLED display industry.First of all,this thesis analyzes the causes of the non-uniform luminance problem and existing solutions from the aspects of OLED device structure,display driving technology,process technology and so on.The two main reasons for non-uniform luminance are the non-uniformity of LTPS devices and the non-uniformity of OLED light-emitting devices and the current solutions are explained in detail,including internal pixel compensation methods,external circuit compensation methods,and external optical compensation methods.Research and analysis of the above-mentioned solutions to achieve the principle of non-uniform luminance compensation,and comparative analysis of their advantages and disadvantages.On the basis of the above research,the design of a compensation system for achieving non-uniform luminance and luminance degradation is proposed.The system simultaneously realizes the improvement of luminance at the factory stage and luminance degradation during later use.Secondly,the thesis studies and designs the overall scheme and function realization of the compensation system.The thesis divides the system design and implementation into overall architecture,hardware architecture,functional modules and other parts.The overall architecture details the basic functional requirements and implementation process for realizing non-uniform luminance and luminance degradation compensation.The hardware architecture specifies the basic hardware and selection requirements that support the realization of system functions.The function module part respectively elaborates the hardware selection evaluation,data processing,and compensation algorithm model design.The hardware selection evaluation focused on the CCD selection evaluation program,and a comparative evaluation of the programs of different manufacturers was carried out.Aiming at the core compensation algorithm model,based on the CCD detection technology design,the luminance non-uniformity detection and compensation is realized,and the luminance degradation compensation model is established according to the OLED life prediction formula.Finally,according to the SEMU standard,a set of system evaluation programs including subjective visual judgment,uniformity improvement,luminance life improvement,optical evaluation,power consumption,etc.were formulated.The 5.5QHD AMOLED display screens were selected for testing and evaluating the system.The results showed that the system compensation realized the effect of reducing the Mura defect level of the specific picture by 65%,increasing the uniformity of the specific picture by 15%,and increasing the long-term residual image test value by 1.9%.Other basic optical characteristics and power consumption are not affected.