Fresnel lens manufacturing apparatus

摘要

An apparatus for producing a Fresnel plate has a mold assembly comprising movable and stationary molds coupled with each other. The mold assembly includes a Fresnel forming face formed on the inside of the movable mold. Melted resin is injected into the mold assembly for forming the Fresnel plate. At least one movable slit is formed through, and arranged inside, the movable mold along a circle concentric with the Fresnel plate and in intermittent or continuous fashion. The movable slit is used for blowing compressed air toward the Fresnel plate. The slit closely surrounds the center of the Fresnel plate. Ejector pins surround the Fresnel plate outside its Fresnel forming face.