METHOD AND DEVICE FOR PRODUCING CONTACT LENS ELEMENTS AND INJECTION MOLD USED THEREFOR

摘要

It is an object of the present invention to provide a method and an apparatus capable of producing a contact lens material with high dimensional accuracy, and a die assembly for injection molding suitably used in the apparatus. The method of the present invention comprises the steps of: injection-molding a first resin mold 4 having a molding surface which provides one of the opposite lens-forming surfaces of the contact lens material, by closing a first die 22a and a second die 22b so as to define a mold cavity 32 therebetween, and injecting a suitable resin material into the mold cavity so as to fill the mold cavity; injection-molding a second resin mold 6 having a molding surface which provides the other of the opposite lens-forming surfaces of the contact lens material, by closing a third die 24a and a fourth die 24b so as to define at least one mold cavity 34 therebetween, and injecting a suitable resin material into the at least one mold cavity so as to fill the at least one mold cavity; separating the first and second dies away from each other such that the first resin mold 4 is held on one of the first and second dies with its molding surface being removed from the other of the first and second dies; separating the third and fourth dies away from each other such that the second resin mold 6 is held on one of the third and fourth dies with its molding surface being removed from the other of the third and fourth dies; introducing a molding material which gives the contact lens material into one of the first and second resin molds 4, 6 which are held respective dies, so that the molding material is accommodated and kept in the one of the first and second resin molds; and moving the die which holds the first resin mold 4 and the die which holds the second resin mold 6, relative to each other, for assembling the first and second resin molds together so as to define therebetween a mold cavity for the contact lens material, the mold cavity being filled with the molding material, so that the intended contact lens material is molded.