Patents Represented by Law Firm Young & Thomposn
  • Patent number: 6074196
    Abstract: 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.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: June 13, 2000
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Mitsuru Shimizu, Yoshihiro Fujita