Design And Study On The Air-flotation Supporting System Of The LCD Screen Detecting Instrument

The non-contact air-floatation transmittion system built based on gas lubrication theory has the advantages of high precision, small friction, no contact damage to the workpiece being detected, so it is one of the core components of the automatic optical detection instrument for the LCD flat panel display screen.This paper is mainly aimed at studying and optimizing performance of the supporting air-film in the air-floatation transmission system of the automatic optical detecting instrument for the LCD flat panel display, and then optimize the structure of main components of this system, aerostatic flotation plate. Based on comprehensive comparison of the throttling effects of various modes such as orifice, capillary and porus compensation, combined with the large, light and thin structure features of liquid-crystal display, devise the capillary throttling scheme and construct the structure model of capillary throttling unit. The process of air flow in the model unit is analyzed theoretically and the functional relation between the model parameters and the air-film bearing capacity, mass flow rate and so on are derived. Depending on the FLUENT software package, selecting the laminar mode, the numerical simulation of flow field of the air-flotation supporting unit is processed. Based on the control variable method, the influence of model parameters such as capillary radius, air-film thickness, supply pressure etc on the air-film characteristics including pressure and velocity distribution, mass flow rate and average bearing capacity is studied in detail. According to the research conclusion, the air bearing unit model is optimized. And then, the three-dimensional modeling of the flow field of the air-flotation plate is carried out. Through the simulation, the performance of the supporting air-film under different arrangement of the through- hole array is compared and ultimately obtain the optimal arrangement model. On the basis of theoretical research and simulation analysis, the engineering optimal design of the structure of air-flotation plate is carried out. Through the detection of the principle prototype of the automatic optical detecting instrument for the LCD flat panel display screen, the results show that air-flotation clearance is less than 50μm, the repeatability and stability of the air-flotation clearance are both in line with the project requirements.