Method and apparatus for producing an optical element

An apparatus for producing a plastic optical element, which apparatus comprises:

• a mold having spaced apart sides between which a cavity is defined in a shape corresponding to the shape of an optical element to be produced, and a feed passage open to said cavity at a portion of the periphery of said cavity, at least one of said sides being made of a light-transmittable material;
• a ring-shaped light source means for emitting light radially thereof, the light capable of causing a photocuring reaction to occur in liquid material from which the optical element is to be formed in said cavity by the apparatus;
• a mirror having a conical surface spaced radially of and confronting said light source means for reflecting the light along an optical path between said ring-shaped light source means and said mold, said surface having an apex and defining a central axis extending through said apex and about which axis said surface is centered;
• a lens disposed between said mirror and said mold in said optical path for focussing the light reflected by said mirror such that the light travels to said mold with the center thereof substantially aligned with the center of said cavity;
• and
• means for moving said mirror and said light source means relative to one another along said axis between a position at which said light source means confronts said mirror at the apex thereof so that light reflected by said mirror at the apex is focussed at substantially the center of said cavity and a position at which said light source means confronts said mirror at a location on said surface thereof from which location light reflected is irradiated in a ring shape on the periphery of said cavity.

An apparatus for producing a plastic optical element, which apparatus comprises:

• a mold having spaced apart sides between which a cavity is defined in a shape corresponding to the shape of an optical element to be produced, and a feed passage open to said cavity at a portion of the periphery of said cavity, at least one of said sides being made of a light-transmittable material;
• light source means for emitting light having a high degree of directivity and capable of causing a photocuring reaction to occur in liquid material from which the optical element is to be formed in said cavity by the apparatus;
• means for causing the light to move along a ring-shaped path on the cavity of said mold, the ring-shaped path being substantially centered at the center of said cavity;
• and
• means for increasing the radius of said ring-shaped path along which the light is caused to move in a step by step manner from a value at which the light having a high degree of directivity is entirely irradiated substantially at the center of said cavity to a value at which the light is irradiated along the periphery of said cavity.