Abstract:
An injection molding method includes a supply step of simultaneously supplying molten resins to a cavity portion from two gate portions and an associating step of associating the molten resins supplied from the two gate portions in a central part of the cavity portion. The supply step supplies the molten resins to the cavity portion from the two gate portions which substantially face each other around the cavity portion. The associating step includes at least one of a first step in the supply step of simultaneously starting the supply of the molten resins to the cavity portion from the two gate portions, and a second step in the supply step of simultaneously starting the injection of the molten resins into the cavity portion from the two gate portions at the same injection rate.
Abstract:
A first lens surface includes a first optically effective surface, and a convexly first engagement portion which protrudes toward a second lens side from an optical extended surface formed with the same curvature as the first optically effective surface as a position substantially corresponding to an outer edge of the first optically effective surface. A second lens surface includes a second optically effective surface larger in diameter than the first optically effective surface, and a convexly second engagement portion, which is provided outside the second optically effective surface, which protrudes toward a first lens side, which is engaged with the first engagement portion, which positions the first lens and the second lens.