| 摘要 |
PURPOSE:To obtain a double focus lens made of plastics in which a small lens does not project from a base lens, by forming the small lens consisting of other prescribed plastic resin in one body at a prescribed position of the base lens consisting of a prescribed resin and by forming the same bending surface with both of them. CONSTITUTION:A small lens 2 consisting of a copolymer of diallyl isophthalate/ benzyl methacrylate (70pts./30pts.) is laminated on a base lens 1 consisting of diethylene glycol bis(allyl carbonate) (CR-39) by ''PHOTOBONE 100 '' (3), and its projected surface is ground to obtain a double focus lens made of plastics having no stepping structure. |
