Abstract

PURPOSE:To manufacture a lens of high optical accuracy with high yield, by filling a mold of desired lens shape with a raw liquid plastic material which can be hardened by the action of ultraviolet rays and by irradiating the material with ultraviolet rays. CONSTITUTION:A raw liquid plastic material 1, which can be hardened by ultraviolet rays, is filled in a mold 4 which has a desired lens shape. The material is hardened at -10--50 deg.C while ultraviolet rays are irradiated upon the material. A plastic lens is thus molded. For example, a liquid resin 1 is supplied from a feeder 2 into a glass mold 4 while the resin is always slightly pressurized. After that, both the sides of the glass mold 4 are irradiated with ultraviolet rays from a radiation source 5. After molding is completed, the cock 3 for the feeder 2 is shut off. The closed faces 6 of the mold 4 are opened toward both the sides of that a molded convex lens is picked out.