Patent ID: 7736552

Claim:
A method for producing a mold for a zonal optical element, the zonal optical element having a circular portion having a circular shape taking an optical axis as a center viewed from a plane surface; at least one zonal surface formed around the circular portion in a ring form; and boundary wall surfaces connecting said circular portion with the zonal surface or connecting the zonal surfaces with each other; said method comprising forming a circular portion of the mold by, while rotating a work around a rotation axis corresponding to the optical axis as a center, moving a tip relative to said work to form the circular portion of the mold on a processing surface of said work perpendicular to said rotation axis and on a straight line passing through the rotation axis of the work; forming a zonal surface of the mold where said tip is relatively moved relative to said work on a tangent line parallel to the straight line and in contact with an outer circumference of the zonal surface of the work so as to form the zonal surface of the mold; and forming a corner portion of the mold between said circular portion of the mold and said zonal surface of the mold by contacting a raked surface of said tip with a boundary wall surface of the mold, which is provided between the circular portion of the mold and the zonal surface of the mold.