Manufacturing method of optical device, and optical device

Abstract

In order to produce high-quality optical elements stably at all times without the flow of molten resin inside an injection molding cavity being hindered by the protrusion of the outer peripheral edge of a lens after compression molding, a cavity formed when a pair of molds for molding is closed is provided with: an optical-function-part molding cavity (); an annular connection-part molding cavity () connected to the outer peripheral edge of the optical-function-part molding cavity; and an edge-part molding cavity () connected to the outer peripheral edge of the connection-part molding cavity. In a compression molding step, a protrusion part is formed by making a portion of a compression molding material bulge out from the connection-part molding cavity into the edge-part molding cavity (). In an injection molding step, the molds are filled by injecting an injection molding material into the edge-part molding cavity (). The resin of the protrusion part that has protruded from the connection-part molding cavity into the edge-part molding cavity () is biased toward one direction of the molds so as not to hinder the flow of the injection molding resin. The biased amount is set such that, when the cross section of the resin that has protruded into the edge-part molding cavity () is divided by a perpendicular bisector (L) that is perpendicular to the optical axis and that divides the thickness of the connection part in half, the cross-sectional area on the biased side includes greater than or equal to 60% of the cross-sectional area of the protruded resin.