2016 Volume 60 Issue 5 Pages 254-260
Large-aperture lenses with diameter > 200 mm for single-lens reflex cameras and television cameras are manufactured by grinding and finish-polishing. In terms of productivity, after the glass lens is shaped by grinding, micro-cracks and grinding traces are removed by polishing sufficiently to be satisfactory to the demands of commercial products. However, the total depth of polishing reaches approximately 10 μm, and prolonged polishing causes deterioration of form accuracy of the lens. Hence, it is necessary to perform ductile-mode grinding efficiently to prevent crack initiation. This study was performed to achieve efficient ductile-mode grinding over the whole optical glass lens. In this paper, a novel ductile-mode grinding method involving control of tool feed rate and workpiece velocity at the same time is proposed, and the grinding performance is evaluated.
