Abstract
Micro-glass lenses for digital cameras and blue laser DVD pick-up devices are generally molded by using micro-aspheric ceramic molds made of tungsten carbides. Demands are increasing for the improvement to the accuracy and surface roughness of the molds with high numerical aperture (NA) optics with steep angles. In order to finish the molds with high accuracy, surface roughness and high NA, a magnetostriction vibration assisted polishing system with was proposed and developed. A small polishing tool is mounted on the head of the magnetostriction vibrator, and the magnetostriction vibrator is fixed on a 3-axis controlled table, and vibrated at the frequency of about 9.2 kHz with the amplitude of 30 µm. The polishing pressure can be controlled at range of 0.2 mN ˜ 20m N with a resolution of 0.2 mN. Some micro-aspheric molds made of binderless tungsten carbide were polished, and surface roughness of about 10 nm Rz was obtained.
