Construction And Optimization Of Air Floatation Module

The development of liquid crystal display technology has placed increasing demands on the online transmission and detection of large-size liquid crystal displays.The traditional roller transmission detection system has been gradually eliminated.Since the 7th generation line,the contactless air floating platform has been used at home and abroad to complete the transmission and detection of the liquid crystal panel.According to the different pressure supply modes,the air-floating platform(the airfloating carrier unit in the paper)is divided into a positive pressure air floating platform and a negative pressure adsorption air floating platform.Firstly,a simple model of the air floating platform is established,and CFD(Computational Fluid Dynamics)is utilized to performs meshing and simulation calculation on the watershed,and simulates the working mode of the two air-floating platforms by modifying the boundary conditions.The simulation results prove that the pressure distribution in the gas film on the negative pressure adsorption air-floating platform is more uniform and suitable.It is applied to the surface defect online detection system of liquid crystal flat panel display.The simulation also proves that the simple model of the air-floating platform cannot achieve the ideal throttling effect,and the front throttle is required.In this paper,a new type of "line-shaped" restrictor model is established.The simulation results show that the throttle has good throttling and voltage-stabilizing ability.After changing the geometric parameters of the throttle,several simulations were carried out and the results show that the cross-sectional area of the throttle has the greatest influence on the throttling effect of the throttle.Then the simple model of the air-floating platform is modified,and the improved model of the air-floating platform is established.After simulation and post-processing,it is proved that the stability of the gas film in the basin has been improved.Change the parameters of the supply pressure,film thickness and other parameters of the vacuum adsorption air-floating platform,and then explore the variation of static characteristics.It is concluded that the maximum pressure drop in the basin appears in the “line-shaped” throttle;the mass flow of the inlet and outlet remains conserved;the bearing capacity and mass flow of the negative-pressure airfloating platform are relatively affected by the positive pressure of the gas supply and the film thickness.Finally,the actual air-floating system is introduced,and the stability of the gas film is tested on the actual negative pressure air-floating platform.The experimental results prove that the film stability meets the depth of field requirements of the optical lens in the liquid crystal display imaging system.The simulation results in the paper have a positive effect on guiding the design and optimization of the air flotation platform.Due to the limitations of the simulation model,the error in the construction of the air-floating system and the complexity of the working environment of the actual air-floating platform,it is normal for the simulation conclusion to deviate from the actual experimental results.Due to the huge cost of constructing the air-floating platform,when exploring the influence of different structural parameters on the performance of the air-floating platform,it can only be obtained through simulation calculation.Therefore,how to eliminate the interference and improve the simulation accuracy is still the focus of the follow-up work.