Needs of digital devices are increasing rapidly in recent years, and the demands of a micro Fresnel glass lenses are increasing especially in a DVD pick-up and dark field systems for automobiles. The glass lenses are molded with a glass press molding process with micro ceramics molds and dies, and then ultra-precision grinding technology of ceramic molds and dies becomes to be a core technology. Authors have successfully developed the simultaneous 2-axes (Y, Z) controlled grinding method, and it was clarified that ultra-precision micro Fresnel shape could be ground using a diamond wheel with sharp edge. In this paper, in order to improve the form accuracy, a new truing method with rare metal truer is proposed and the effects of the molybdenum truer are tested. Finally, with the developed truing system the micro diamond wheel was trued, and an aspherical mold of Fresnel glass lens for infrared DOE is ground to evaluate grinding performances.
