PURPOSE: To improve the eccentric accuracy on an optical spherical surface of a metal die for molding a lens while simplifying the working of metal die by applying bell holders of a polishing machine to a pair of optical spherical surfaces formed opposed to both end faces of a metal die to sandwich the metal die and polish the outer peripheral surface of the metal die.
CONSTITUTION: A post-like metal die 30 for molding lenses having the circular outer peripheral surface is formed on one end face 32 with an optical spherical surface and on the other end face with an optical spherical surface 35. Next, the end face 39a of one bell holder 39 of a pair of cylindrical bell holders 39, 40 provided coaxially opposed to a polishing machine 41 is applied to the optical spherical end face 32 of metal die 30, and the end face 40a of the other bell holder 40 is applied to the other optical spherical end face 35 of metal die 30 to sandwich the metal die 30 between a pair of bell holder 39, 40. Thus, the outer peripheral surface of metal die 30 is polished by a grinding wheel 42 of the polishing machine 41 to improve the eccentric accuracy on optical spherical surface 32 formed on one end face 31 of metal die 30.
Minato, Akito
Matsuda, Masaharu
Hoshi, Kenichi
Kobayashi, Toshio