Abstract: A molding method for optical element is disclosed in which a glass material prepared for weight is introduced into a mold and then heated to soften, and subsequently pressed with the mold to mold an optical element. The glass material is heated to have a viscosity of 10.sup.5 to 10.sup.7 dPaS and press-molded with the mold having a temperature equivalent to a viscosity of 10.sup.9 to 10.sup.11 dPaS of the glass material.

Abstract: Lens surfaces are transferred by press-molding a glass material (16) by an upper mold (1) and a lower mold (2). After the lens surfaces are transferred, the outer circumferential portions of the upper and lower molds (1, 2) are clamped and pressed sideways to correct a shift between the optical axes of the transfer molding surfaces of the upper and lower molds (1, 2) and an inclination of the optical axes.

Abstract: An optical lens press-molded so that within at least the optically effective diameter thereof, the thickness thereof may become greater from the center of the optical axis thereof toward the marginal portion of the lens, characterized in that at least one of the both lens surfaces thereof is a spherical or aspherical concave lens continuous from a transferred surface formed so that in the area outside the optically effective diameter thereof, the thickness of the lens may be limited away from the extension of a curved surface of a radius of curvature setting the optically effective diameter toward the outer diameter of the lens, and forming the transferred surface up to at least the required outer diameter of the lens, and a free surface portion is left outside the outer diameter of the lens during molding.

Abstract: A manufacturing method for an optical glass element having a refractive index equal to a design value after press-molding. A glass material of specified composition is melted and press-molded while it is in the molten state. The refractive index of the glass material is calculated by substracting a change in the refractive index of the glass material resulting from the press-molding from a required refractive index for a molded glass element.

Abstract: A method of molding an optical element numerically analyzes the thermal stress produced on a molded optical element product within a mold in a visco-elastic temperature range or elastic temperature range of an optical element material in a cooling step of the molding process on the basis of a visco-elastic characteristic of the optical element material. A correction for the molding face of the mold is made on the basis of the value obtained by the numerical analysis so that any error between the optical functional face of optical element molded by the mold at room temperature and the optical functional face set on design may fall within a tolerance, thereby determining the molding face adapted to the shape of the optical functional face set on design.

Abstract: There is disclosed a method for molding an optical element, by preparing an upper mold member and a lower mold member for press molding a glass material, heating the mold members together or individually to a predetermined temperature, deforming the glass material according to molding faces of the mold members by a pressing force applied to the mold members, then transferring the mold members and the molded glass to a cooling step and subsequently taking out the molded glass by opening the mold members, thereby transferring the optically functional faces corresponding to the molding faces of the mold members, to the glass material.

Abstract: A method of molding an optical element numerically analyzes the thermal stress produced on a molded optical element product within a mold in a visco-elastic temperature range or elastic temperature range of an optical element material in a cooling step of the molding process is on the basis of a visco-elastic characteristic of the optical element material. A correction for the molding face of the mold is made on the basis of the value obtained by the numerical analysis so that any error between the optical functional face of optical element molded by the mold at room temperature and the optical functional face set on design may fall within a tolerance, thereby determining the molding face adapted to the shape of the optical functional face set on design.