High-precision compensation method for the form error of a glass aspheric lens in precision glass molding

Addressing challenges in controlling viscoelastic shrinkage-induced thermal deformation errors in precision glass molding, this article proposes a mold compensation method that combines the pre-compensation of form error prediction based on molding simulation and higher-order form error compensation based on molded glass lens. Results indicate that the coupling effects of volume relaxation and glass/mold thermal expansions are identified as primary causes of glass lens form error. The form error of the molded lens can be markedly reduced through the mold pre-compensation, with the form error of the aspheric lens being pre-corrected from the simulation-predicted PV 7.187 μm to approximately 0.6 μm. Further compensating for higher-order form errors in molded glass aspherical lenses enhances the form accuracy, resulting in an improvement of the aspherical lens form accuracy from PV 0.6186 μm to PV 0.1525 μm. This approach effectively improves compensation accuracy, reduces compensation times, and is applicable to industrial glass lens production.