Abstract: The present invention relates to an optical element comprising: a optical glass made of a phosphate glass or a fluorophosphate glass; and an optically functional film formed on a surface of the optical glass, wherein the optically functional film comprises two or more layers made of different materials, and the outermost surface layer thereof is made of a material(s) having low reactivity with phosphoric acid.

Abstract: The present invention relates to an optical element comprising: a optical glass made of a phosphate glass or a fluorophosphate glass; and an optically functional film formed on a surface of the optical glass, wherein the optically functional film comprises two or more layers made of different materials, and the outermost surface layer thereof is made of a material(s) having low reactivity with phosphoric acid.

Abstract: It is an object of present invention to select the most suitable composition and molding condition for obtaining a glass having a desired refractive index by press molding without any annealing treatment, for a short period of time so as to produce efficiently the glass.

Abstract: A glass melting apparatus is provided with a clarifier tank adapted to clarify melted glass which is obtained by melting a raw glass material. Partition walls are provided in the clarifier tank so as to define a meandering flow passage through which the melted glass flows. A bottom of the clarifier tank is sloped so that the flow passage ascends from an upstream side thereof to a downstream side thereof.

Abstract: In an apparatus for press-molding an optical element by pressing a glass material with a plurality pairs of upper dies and lower dies, a lower die pressure applier is operable to apply pressure to the lower dies. A body die is adapted to guide the upper dies and the lower dies. A pressure generator is operable to lift the body die. An aligner is operable to slide the body die along the upper dies to align each of the upper dies. The aligner has a hunger supporting each of the upper dies in a hanging manner, and is operable to cause each of the upper dies to move in a plane which perpendicularly intersects a movement axis of the body die, when the body die is lifted along the upper dies by the pressure generator.

Abstract: The invention provides: a mold for molding optical glass, the mold comprising: a mold base; and a protective film comprising one or two or more layers formed on the mold base, the outermost layer of the protective film containing one or more elements selected from the group consisting of Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, Bi, S, Se, and Te; a process for producing the mold; and a process for press-molding with the mold.

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: A method and apparatus for forming an optical device of a desired shape presses a heat-softened optical material using a set of molds. The optical material is aligned with respect to the molds by two or more aligning members which move around the center of the mold relative to each other. The optical material may also be aligned by inserting a pin into an aligning hole which is fixed to the mold body and has been aligned with respect to the molds.

Abstract: This invention is to prevent coloring or clouding of the molded article, and also to prevent fusion between the glass blank and the mold member and crack formation in the molded article.The glass blank is provided with the surface layer containing a lower content in water-soluble components than in the core part of the glass base, and a hydrocarbon coating layer formed on the layer. The blank is then press molded.

Abstract: Disclosed is a glass blank used in a producing process for molding an optical element by heating a glass material and press molding the glass material in a mold having optical functional surfaces. Employed is the glass blank having the glass surface coated with a reaction preventive layer and a hydrocarbon layer or with the hydrocarbon layer.