| 摘要 |
PURPOSE:To prevent a distortion from generating with uneven cooling shrinkage, by a method wherein a solidification speed which varies according to a thickness distribution of a lens molded body is controlled evenly by accelerating the speed forcibly with cooling in relation to thick part and delaying it with heating by magnetic induction heating or a heating fluid in relation to a thin prt. CONSTITUTION:A heating device 12 with a magnetic coil 14 and magnetic substance is provided on the circumference of front molds 3a, 4a for molding a convex lens and a device 13 with a flow path 16 of a cooling fluid is provided on the central part forming a thickness of a lens. The heating device 12 with an electromagnetic coil 14 is provided on the central part of the front molds 3a, 4a for molding a concave lens and a cooling device 13 with the flow path 16 is provided on the fringe part. At the time of molding of the convex lens, acceleration in solidification of a thick part is contrived by feeding the cooling fluid into the flow path 17 of the central part, a electromagnetic coil 20 in a flow path 18 of the fringe part is electrified and control of cooling and solidification of a thin part is contrived. Then at the time of molding of the convcave lens, electromagnetic coil 19 of the flow path 17 is electrified, the cooling fluid is fed into the flow path 18 and unification of cooling and solidification speeds is performed. |
