Manufacturing method of optical device, and optical device

A manufacturing method of an optical device that obtains the optical device through molding processing using a pair of molding molds including a first mold and a second mold,

• wherein each of the pair of molding molds includes an optical functional part transfer surface that forms an optical functional part;
• a connecting part transfer surface that forms a connecting part stretching to an outer peripheral part of an optical functional surface;
• an inclination part transfer surface that forms an inclination part stretching to an outer peripheral part of the connecting part transfer surface;
• and an outer peripheral part transfer surface that forms an outer peripheral part stretching to the inclination part transfer surface,
• wherein the pair of molding molds when being closed includes a cavity that is formed by an optical functional part molding cavity formed by the optical functional part transfer surfaces;
• a connecting part molding cavity formed by the connecting part transfer surfaces;
• and an edge part molding cavity formed by the inclination part transfer surfaces and the outer peripheral part transfer surfaces stretching to the inclination part transfer surfaces,
• wherein the inclination part transfer surfaces of the first mold and the second mold have inclination angles that are widened such that the thickness of the optical device in an optical axis direction increases from the connecting part transfer surface side toward the outer peripheral part transfer surface side, respectively,
• the method comprising:
• a compression molding step of filling the optical functional part transfer surface of one mold of the pair of molding molds with a compression molding material having a smaller volume than the volume of the optical device, expanding the compression molding material while the molding molds being closed to transfer the shapes of the optical functional part transfer surfaces and the connecting part transfer surfaces of the molding molds to the compression molding material, and forming a protrusion part formed by a portion of the compression molding material bulging from the connecting part molding cavity to the edge part molding cavity side, and
• an injection molding step of filling the edge part molding cavity with a molten injection molding material in a state where the pair of molding molds are closed, and forming an injection-molded part at an outer periphery of the compression-molded compression molding material, and
• wherein the protrusion part is biased during the compression molding step such that, when a cross-sectional shape of the protrusion part that has protruded from the connecting part molding cavity to the edge part molding cavity is divided into two by a perpendicular bisector that is perpendicular to an optical axis and bisects the thickness of the connecting part molding cavity in the optical axis direction, a side with a larger area is defined as HS1, and a side with a smaller area is defined as HS2, the area of the HS1 is larger than or equal to 60% of the cross-sectional area of the protruded compression molding material.