Method of manufacturing lens

A method of manufacturing lenses, the method using a molding unit to manufacture lenses out of a structure with a plurality of lens intermediates coupled to each other through a runner, the molding unit including a plurality of first molding dies, a plurality of second molding dies, and a holding member for holding the first and second molding dies,

• the holding member being provided with first opening parts, second opening parts, and molding chambers placed at a plurality of places, the first opening parts and the corresponding second opening parts being aligned along predetermined axes and coaxial with each other about the predetermined axes, the molding chambers existing between the first opening parts and the corresponding second opening parts, the holding member being constructed of a plurality of joined components capable of being separated from each other, a path through which the lens intermediates and the runner pass being exposed at least one of joint surfaces of the components, the path allowing the introduction of the lens intermediates into the corresponding molding chambers,
• the first opening parts each receiving the corresponding first molding die inserted into the first opening part and the second opening parts each receiving the corresponding second molding die inserted into the second opening part, the first molding die and the corresponding second molding die being capable of moving to get closer to and farther from each other along the corresponding predetermined axis,
• the method comprising the steps of:
• (a) preparing the structure;
• (b) guiding the lens intermediates to predetermined positions in the corresponding molding chambers through the path, and combining the separated components of the holding member;
• (c) heating the lens intermediates;
• (d) molding the lens intermediates to form molded lenses by causing the first molding dies and the corresponding second molding dies to move to get closer to each other along the predetermined axes to apply a pressing pressure to the lens intermediates, the step (d) being performed after the step (b) and simultaneously with the step (c);
• (e) removing the molded lenses from the first molding dies and the corresponding second molding dies by causing the first molding dies and the corresponding second molding dies to move to get farther from each other along the predetermined axes, the step (e) being performed after the step (d);
• and
• (f) separating the molded lenses from the runner by cutting the structure, the step (f) being performed after the step (e).