Abstract: A lens cap having a lens formed in the window at its top portion, used for a semiconductor laser, etc., using an aspherical lens instead of a spherical lens with large aberration. This invention proposes a lens cap having an aperture formed at its top portion, comprising a lens formed to fill the aperture in such a manner as to bulge on both sides of the aperture and further to extend beyond the circumferential edge defining the aperture along the top portion on both sides of the top portion or under the top portion only, wherein the outer circumference of the portion extended under the top portion contacts the lateral inside wall and top inside wall of the cap member. So, this invention can provide a cheap lens cap with high performance.

Abstract: A molded glass lens with a lens holding cylinder integrated, comprising the lens holding cylinder having an adequate number of through holes formed in it and forming a hot working space together with a mold during molding and a glass lens proper molded in the lens holding cylinder, wherein the excessive portion of the base material of the lens has flowed into said through holes, and also proposes a production device thereof.