| 摘要 |
PURPOSE:To perform molding at a high speed with high accuracy, by a method wherein a photoset plastic material is injected in a mold having the injection hole communicating with the outer periphery of the cavity thereof to store the excessive material in the injection hole and irradiated with light, whose luminous intensity distribution becomes gradually weak from the center part of the cavity toward the outer periphery, to be cured. CONSTITUTION:Lens surfaces 3, 4 corresponding to the shape of a lens are respectively formed to upper and lower molds 1, 2 using quartz glass and difference in level 5 for holding the thickness of the lens is formed to the lower mold 2. An injection hole 7 communicating with a cavity 6 is provided to the lower mold 2 and a part of the difference in level 5 is set to a recessed part 8 to keep communication. The cavity 6 is filled with a photoset plastic lens material 9 and the injection hole 7 is also filled with the excessive same material 10. Curing advances from the surface 3 of the lens to the surface 4 thereof at the reaction speed corresponding to the intensity of the light shown by an arrow. The cured part 11 is grown with the elapse of time but, by selecting the intensity distribution of light, the central part is necessarily cured up to the surface 4 of the lens at first and the cured part 11 of outer periphery gradually reaches the surface 4 of the lens. The shrinkage due to curing is compensated by the inflow of the excessive material 10 to the cavity 6. |
