Patent attributes
A method for producing a mold for a zonal optical element including forming a circular portion where, while rotating a work around a rotation axis corresponding to the optical axis as a center, a tip is relatively moved relative to the work to form the circular portion at the mold side corresponding to the circular portion on the processing surface of the work perpendicular to the rotation axis; forming a zonal surface where the tip is relatively moved relative to the work to form a zonal surface at the mold side corresponding to the zonal surface; and forming a corner portion between the boundary portion at the mold side and the zonal surface at the mold side wherein a raked surface of the tip is in contact with a portion corresponding to the boundary wall surface.
