Mold for plastic lens

Abstract

Abstract PURPOSE:To release a mold easily, keeping the precision of lens, by means of air injection between a lenticular surface of mold and a surface of lens, where the air enters through a channel formed by moving an insert in a lens mount in the opposite direction to a cavity at the time of releasing. CONSTITUTION:Initially a sliding insert 6 is advanced to push a movable mount 5. Then, an injection molding machine 14 injects molten resin, with which a cavity 1 is filled, and the resin in the cavity 1 is pressurized and formed by means of the lenticular surface 5a of movable mount 5 and the lenticular surface 6a of sliding insert 6. After the resin in the cavity 1 is solidified, fixed mold 2 and movable mold 4 are opened and the lens projects from the mold by the advance of the movable mount 5 and the sliding insert 6. An opening 21 arises by retreating the sliding insert 6 and compressed air is fed to this opening through a pipe 19 and an air chamber 20. Consequently, the air is injected on the surface 5a of the lens, on which the adhesion force is eliminated, and the mold can be easily released without any damage or any precision-degradation of the precisely formed plastic lens.

Inventors

• 👤 Shoki Eguchi
• 👤 Masao Takagi
• 👤 Hisao Inage
• 👤 Norio Yatsuda

Bibliographic Details