Study on ultra precision finishing of micro aspherical surface by circular vibration assisted polishing

Abstract

Demands are increasing for micro aspherical lenses in various optical devices and the micro glass lenses are generally moulded by glass molding process with micro aspheric dies and moulds made of ceramic such as tungsten carbide. These dies and moulds are mostly ground with micro diamond wheels, but require additional finishing process as the mould size become smaller and the required accuracy becomes higher. In the previous paper, a lateral ultrasonic vibration assisted polishing machine/system is developed in order to finish the micro aspheric moulds1). In this paper, circular vibration assisted polishing system was developped in order to improve surface roughness furthermore and its polishing characteristics were tested with the tungsten carbide workpiece