Optimization Design Of Scattering Dots On Light Guide Plate

Nowadays,the liquid crystal display has become the most widely used display screen in people's lives due to its advantages of high image quality and low energy consumption.The liquid crystal display is composed of a liquid crystal panel and a backlight module.The liquid crystal panel itself does not have light-emitting properties,and the backlight module is the provider of the light source of the liquid crystal display,so the uniformity of the light output of the backlight module will directly affect the display quality of the liquid crystal display.In the backlight module,the light guide plate is an important component.Its function is to transmit light,and rely on the dense scattering dots distributed on its bottom surface to convert the light emitted by the point light source or the linear light source into a uniformly emitted surface light source.Therefore,in order to obtain a backlight module with higher light uniformity,this paper mainly studies the distribution pattern of scattered dots densely distributed at the bottom of the light guide plate,and systematically analyzes the parameter values in the function of the distribution pattern of the scattered dots to summarize a set of reasonable,efficient and practical design schemes for the arrangement of scattering dots,and obtained a set of parameter values that can make the backlight module's light uniformity reach a higher level,and realized the optimization of the design scheme of the scattering dots arrangement and the improvement of the backlight module to reach the goal of light uniformity.The main research contents and conclusions of this article are as follows:(1)Through the understanding of the structure of the backlight module and the side entry type and the light guide principle of the light guide plate,it is confirmed that the design of the arrangement of the scattering dots at the bottom of the light guide plate has a great influence on the light uniformity of the backlight module.(2)By understanding the optical characteristics of photometry,colorimetry,non-imaging optics,geometric optics,LED light sources and the light guide principle of the light guide plate,an expression of the regularity of the arrangement of scattering dots is established,and the expression is affected by a comprehensive and systematic analysis of the relationship between the parameters of the scattering dot arrangement rule and the size of the light guide plate.It is confirmed that a comprehensive and systematic design of the light guide plate and the arrangement of scattering dots can improve the light uniformity of the backlight module.(3)Model the backlight sample of a mobile phone in TracePro software using the derived expression pattern of scattering dot arrangement,design its scattering dot distribution model in a successful way,and finally obtain the simulated illuminance of the light exit surface of the sample figure,the result shows that the light uniformity is 74.387%.(4)Using an illuminance meter to actually measure the illuminance of the light emitting surface of the backlight module sample,the result shows that the light uniformity is 74.395%.Since the light uniformity of 74.395% of the test result is approximately the same as the light uniformity of 74.387% of the simulation result,the simulation result of the light uniformity of the backlight module sample is confirmed to be correct.(5)In order to continue to improve the light uniformity of the backlight module samples,the three parameters of the initial dot spacing of the dots,the change value of the dot spacing between dots and the diameter of the dots are modified in TracePro software Obtained different scattering dot arrangement models,obtained the simulated illuminance map of the light guide plate emitting surface under all the scattering dot arrangements,and drawn the curve change graph of light guide plate emitting surface illuminance.After analyzing the curve change graph of the illuminance,the light output can be obtained The values of the above three parameters with the best uniformity are: the change value of the line spacing of the dots is 0.0008 mm,the diameter of the dots is0.02 mm,and the initial line spacing of the dots is 0.2mm which provides a new design for the design of the scattering dots.(6)Use the optimized initial dot spacing,dot spacing variation,and dot diameter parameter values to create an optimized scattering dot pattern in TracePro software,and apply it to the backlight module sample to rebuild after the model is ray traced.The final result shows that the uniformity of the optimized backlight module can reach to 80.785% uniformity which is higher than 74.387% before optimization.In that case,the correctness of the optimized arrangement scheme of scattering dots is confirmed.