| 摘要 |
PURPOSE:To obtain a plastic lens of high accuracy having no surface strain and a predetermined surface shape. CONSTITUTION:An airtight cavity 8 becoming the final shape of a lens is formed by casting molds 6, 6' pervious to ultraviolet rays. The casting molds 6, 6' are made dividable from a parting surface 13 and divided to insert a lens blank 3 in the cavity 8. Optical strain is removed from the lens blank 3 but, because of this, strain is present in the surface shape of said blank 3. In such a state that the lens blank 3 is inserted in the cavity 8, the cavity 8 is filled with a syrup 4 of a plastic material whose refractive index is almost equal to that of the lens blank 3 and irradiated with ultraviolet rays from the outside through the casting mold 6 or 6'. By this method, the syrup 4 is polymerized to be unified with the lens blank 3. |
