FORMED NONSPHERICAL LENS

摘要

PURPOSE:To obtain a formed nonspherical lens having a desired optical effective diameter by providing a nonspherical machined diameter of a forming mold with a difference between the shrinkage length of a lens and the shrinkage length of the forming mold added to the optical effective diameter of the lens. CONSTITUTION:A top force 1 and a bottom force 2 in which the optical functional surface of at least one thereof has a nonspherical shape and a drum mold 5 for aligning the axial center of the forming mold and sliding the mold in the vertical directions are used to form a nonspherical lens. In this case, the machined diameter of a nonspherical surface of the forming mold is regulated to a difference between the shrinkage length of the lens from the heating temperature to ordinary temperature [the optical effective diameter (E) of the lens at a high temperature - the optical effective diameter (C) of the metallic mold at ordinary temperature] and the shrinkage length of the forming mold from the heating temperature to ordinary temperature [the optical effective diameter (D) of the metallic mold at the high temperature - the optical effective diameter (C) of the metallic mold at ordinary temperature] added to the optical effective diameter (C) of the lens.