Abstract: A method for manufacturing a plastic lens that can enhance productivity by shortening the cooling time without affecting transferability even if the temperature of a mold is set low and may be applicable to an existing injection molding apparatus. When a plastic lens having a prescribed lens shape is manufactured by injecting and filling a molten resin in a cavity 3 formed between a movable mold 1 and a fixed mold 2, a molding surface of at least one of cavity forming member insert molds 11 and 12 is formed in glass substrates 11a and 12a, and for a period of time for which filling is completed with the cavity 3 being filled with a raw material resin that flows into the cavity 3, temperature control is conducted such that the surface temperature of the molding surface does not exceed the glass transition temperature of the raw material resin.

Abstract: A method for manufacturing a plastic lens that can enhance productivity by shortening the cooling time without affecting transferability even if the temperature of a mold is set low and may be applicable to an existing injection molding apparatus. When a plastic lens having a prescribed lens shape is manufactured by injecting and filling a molten resin in a cavity 3 formed between a movable mold 1 and a fixed mold 2, a molding surface of at least one of cavity forming member insert molds 11 and 12 is formed in glass substrates 11a and 12a, and for a period of time for which filling is completed with the cavity 3 being filled with a raw material resin that flows into the cavity 3, temperature control is conducted such that the surface temperature of the molding surface does not exceed the glass transition temperature of the raw material resin.

Abstract: There is provided a method for producing a plastic lens in which, without heating a die, a resin injected and filled into a cavity can be maintained at a temperature higher than a glass transition temperature of the resin only for a time until the filling of the resin into the cavity terminates, whereby the generation of a surface defect such as jetting or a flow mark, or a weld line can be prevented. In producing the plastic lens having a predetermined lens shape by injecting and filling a molten raw material resin into a cavity 3 formed between a movable die 1 and a fixed die 2, a part or all of a molding surface of at least one of inserts 11 and 12 as cavity forming members is formed by using insulating materials 11a and 12a made of a glass raw material.