Research On Vision System Of Mounting Machine Specially Used For Direct Type Lens

With the continuous development of science and technology and the improvement of human living standard,there is a more and more increasing demand for modern electronic products,and liquid crystal display(LCD)products almost enter every household due to their low energy consumption etc.Large-size LED backlight LCD products have become the mainstream,and huge markets force the companies to produce them automatically.As one of the important parts of the direct type backlight source module,there is a demanding requirement for the mounting process of pasting direct type lens on lamp strip.The size of the lens is relatively large,which requires strict positioning accuracy and positioning speed.At present,domestic manufacturers mostly employ imported universal mounting machines for production which causes the high cost and low equipment utilization rate.In order to control the cost,some medium-and-small size enterprises adopt a traditional manual way,which brings about unguaranteed reliability and is not conducive to the long-term development of the enterprise.Therefore,it is of great significance to study the system of mounting machine specially used for direct type lens for the development of LCD industry.In this paper,the visual system of mounting machine specially used for direct type lens is studied.Firstly,aiming at the direct type lens mounting process,the main structure and function module of the mounting machine system are analyzed,then the actual technical requirement of the mounting machine is considered,and a visual system for the image is designed and constructed to capture the moving direct type lens.The basic model and principle of visual system calibration are studied,combined with the gantry machine vision system platform model and motion characteristics,the vision coordinate system is established and then a simplified calibration method based on plane constraint is proposed to unify the coordinate systems.Then,the principle of position correction of direct type lens is analyzed.The image processing algorithm of visual system is studied.The edges are extracted from the image acquired by the visual system,a method for the quick fitting chamfer rectangle based on the least squares line fit is proposed,so as to obtain the position information of its angle and center.Template matching algorithm of gray value optimized by image pyramid is studied,and the accuracy and speed of this optimized algorithm are verified by experiments.Finally,the software for visual system is programmed based on C# and Halcon dynamic library.The algorithms mentioned in this paper are tested,and the feasibility of the algorithm is verified by the running time,stability and positioning accuracy,which can satisfy the requirement of the automatic mounting of direct type lens.