FRESNEL LENS MANUFACTURING DEVICE

摘要

PURPOSE:To enable mold lubrication without cracks and prism-shaped breakage at a low stress by providing mold-parting pins which are long at the corner and become shorter toward the center of each side on the periphery and also providing a single drive source which moves the mold-parting pins vertically at the same time. CONSTITUTION:Mold-parting pins 6c arranged on the periphery of a fresnel lens molding die 3 are designed so that they are long at the corner and become shorter toward the center of each side. The mold-parting pins 6c formed as the above-mentioned are activated to move up and down simultaneously using a signal drive source (hydraulic cylinder) 80. Then the process of releasing the Fresnel lens 2 is allowed to take place coaxially at low stress, so that the mold-releasing speed is kept constant.