| 摘要 |
PURPOSE:To enhance the surface accuracy over the whole region of the rounded surfaces of a lens by a method wherein lens inserts having a lens molding surface are inserted respectively in a stationary plate and a movable plate and a flat plane part, which intersects with the axis center line of the lens insert at right angles, is provided at the peripheral edge of each lens insert having the rounded surface. CONSTITUTION:A lens insert, which consists of an inside stationary sleeve 34 and a stationary piece 60, is assembled to an outside stationary sleeve 33, which is fittingly fixed to a stationary plate 32. On the other hand, a concave rounded surface, which has a curvature corresponding to that of a lens and outside of which a flat plane part intersecting with the axis center line of a movable piece 61 at right angles is formed, is made on the upper end surface of the movable piece (a lens insert) 61 which is shiftably fitted in a movable sleeve 40. The upper and lower surfaces of a cavity 54 are made of the rounded surface of the stationary piece 60, the flat plane part of the inside stationary sleeve 34, the rounded surface and flat plane part of the movable piece. A plastic lens injection-molded with the above-mentioned molding die can hold favorable surface accuracies on the rounded surfaces. |
