Optical element, optical apparatus, system, and method of manufacturing the optical element

A method of manufacturing an optical element made of resin,

• the optical element including
• a first surface that serves as an optical surface,
• a second surface that serves as an optical surface,
• a third surface that serves as an optical surface, and
• a fourth surface that connects to the third surface,
• the method comprising:
• inserting a first molded portion made of resin, into a cavity of a mold that includes a transfer surface, the transfer surface including a surface for forming the first surface, the second surface, the third surface, and the fourth surface through transfer;
• and
• injecting molten resin from a gate into a space between the first molded portion and the transfer surface of the mold and forming a second molded portion outside the first molded portion,
• wherein the molten resin injected from the gate is split and flows along the first molded portion, and then one portion of the molten resin and another portion of the molten resin meet with each other and form a weld,
• wherein the third surface includes a peripheral area and an inner area, and a distance from an outer edge of the third surface to a position in the peripheral area is equal to or smaller than 5 mm and a distance from the outer edge of the third surface to a position in the inner area is larger than 5 mm, and
• wherein the weld is formed in at least any one of the peripheral area of the third surface and the fourth surface.