Single point diamond turning and compensation for micro-lens array

To improve the efficiency and consistency of machining micro-lens arrays using single point diamond turning, a theoretical model of surface residuals was proposed in this study. A compensation method for the model was then studied. The micro-lens array was regarded as a freeform surface. The radius of curvature at each cutting point along the cutting direction was calculated by establishing an slow slide servo (SSS) cutting model. Combined with the tool equivalent tilt angle and lathe delay models, the theoretical surface residuals of the freeform array in SSS were obtained. Subsequently, the actual surface residuals were measured and processed using in situ measurement. The theoretical and measured surface residuals were then compared and the surface residuals were compensated for in the machining program. The theoretical surface residuals are consistent with the actual ones, with an error range of [-0.7 μm, 0.3 μm]. The peak to valley (PV) value is reduced from 5.4 μm to 0.6 μm after compensation. Therefore, the single point diamond turning and compensation method presented in this study is able to predict the surface residuals and significantly improve machining accuracy and consistency. © 2022, Science Press. All right reserved.