Research On Ultra-precision Turning Technology Of Microlens Array

As one kind of optical microstructure components, microlens array is widely used applied for military and civil use with its advantages of optical performance such as miniaturization and light weight. Because of the broad application of microlens array, a great deal of energy and resources are spent on the research on design optimization and manufacturing process of microlens array at home and abroad in recent years. At present, microlens array is commonly manufactured by non-traditional machining and ultra-precision machining. Ultra-precision machining technology, which is a feasible research direction of microlens array, can realize processing size miniaturization, its precision can reach nanoscale, with great significance in improvement of machining precision, surface quality and processing efficiency.This thesis mainly researches on ultra-precision machining technology of microlens array. The research content contains turning trajectory planning of microlens array, how to choose the turning tool, prediction of machining surface morphology, processing experiment and measurement.First, description model for plane and curved microlens array with different arrangement has been built. The discrete tool tip coordinate data of processing trajectory can be produced by subtense-limited interpolation algorithm. Tool trajectory is optimized by means of tool tip compensation for sphere surface. The compensation is concentrated on tool slide in order to ensure the stability of the machine during processing.Secondly, the critical geometric parameters of turning tool are calculated, which can be reference of turning tool geometry parameters selection. Meanwhile, in order to verify trajectory planning, the model of processing surface morphology prediction has been established, using tool tip data of process program as input. By using prediction model, the predicted result is produced and the process precision is analyzed. And the precision influence of some process factors are studied in the meantime.Finally, the machining experiment of microlens array is conducted. Trial cutting is used for toolsetting in order to limit the toolsetting error of the diamond tool. Plane and curved microlens array with different arrangement are processed by the ultra-precision machine in C axis mode of DNC system. The 2D profile of the parts is measured by Taylor Hobson contourgraph. The 3D morphology is measured by OLS3000 laser scanning confocal microscope. With analysis of measurement, the theories of tool trajectory planning and morphology prediction are proved, and the problems of processing experiment are analyzed.