Profile Compensation for Single-Point Diamond Turning of Microlens Array

To improve the efficiency and consistency of machined microlens array using single-point diamond turning technology, a theoretical model of surface form error is proposed in this paper. Then, a compensation method for this model is studied. In the proposed tool equivalent tilt angle model, the microlens array is regarded as a freeform surface. The corresponding curvature radius of the surface at each cutting point along the cutting direction is calculated by establishing a slow slide servo cutting model. In the spatial form error model, the assumption is that surface form error has a linear relationship with z-axis maximum speed vz. An empirical linear equation is obtained and verified, with a maximum deviation of 0.4 mu m. Then, after machining, the surface form error is measured and processed using on-machine measurement. The theoretical and measured surface form errors are consistent. The surface form error is compensated in the machining program. The peak-to-valley value is reduced from 5.4 to 0.6 mu m after compensation. Findings show that the single-point diamond turning and compensation method for the microlens array presented in this paper can predict the surface form error and significantly improve machining accuracy and consistency.