| 摘要 |
PURPOSE:To obtain at low cost a core useful for molding lens having positioning standard curved surface, suitable for collimation lens, etc., without the need for high- precision processing, by fitting a specific molding ring into the circumference of the lens transfer curved surface of a core having lens transfer curved surface of the title mold. CONSTITUTION:The internal of the top force 11 of the title mold made up of top force 11 and bottom force 12 is provided with a core 13, and a spherical or nonspherical convex lens transfer curved surface 13a is formed on the lower end surface of this core 13 along with fitting a molding ring 4 into said core 13. And the standard surface transfer curved surface 14a of this molding ring 14 is connected, without any gap, to the convex lens transfer curved surface 13a of the core 13, and a high-precision finishing is made so as to represent a tapered surface extending outwards at equal angles from the outer periphery of the axis center of the core 13 followed by fixing the curved surface 14a with a press member 15. A second core 16 is provided in the bottom force 12, on the outer surface of which a spherical or nonspherical concave transfer curved surface 16a is formed. Thence, heated and softened vitreous material is fed between the cores 13 and 16, which are put to pressure contact operation, thus forming a lens 30 through the transfer surfaces 13a, 16a and the standard surface transfer curved surface 14a. |
