Abstract:
Provided is an apparatus for forming glass elements, which includes top and bottom die assemblies, each of the die assemblies comprising a core mold, a mold die which supports the core mold, and a die plate, and a glass material being interposed between the top and bottom core molds, a first fastening member, which fastens the mold die and bottom die plate of the bottom die assembly together, a second fastening member, which fastens the die plate of the bottom die assembly and the heat insulating cylinder together, a third fastening member, which fastens the mold die and die plate of the top die assembly together, and a fourth fastening member, which fastens the die plate of the top die assembly and the heat insulating cylinder together. Each of the first to fourth fastening members is made of a material selected from the group consisting of carbon and molybdenum.
Abstract:
The present invention relates to low-dispersion optical glass having a low glass-transition temperature suited to precision press molding, a press molding preform comprised of this glass, a method of manufacturing the same, an optical element, and a method of manufacturing the same. The optical glass comprises, given as molar percentages, 28 to 50 percent of P2O5; more than 20 percent but not more than 50 percent of BaO; 1 to 20 percent MgO; a sum of Li2O, Na2O, and K2O exceeding 3 percent (with 0 to 25 percent of Li2O, greater than or equal to 0 percent and less than 10 percent of Na2O, and 0 to 12 percent of K2O); more than 0 percent but not more than 15 percent of ZnO; 0 to 25 percent of B2O3; 0 to 5 percent of Al2O3; 0 to 8 percent of Gd2O3; 0 to 20 percent of CaO; 0 to 15 percent of SrO; and 0 to 1 percent of Sb2O3; with a sum of oxide contents of P, Ba, Mg, Li, Na, K, Zn, B, Al, Gd, Ca, Sr, and Sb being greater than or equal to 98 percent. The press molding preform is comprised of the optical glass. In the method of manufacturing a press molding preform, a glass melt gob of prescribed weight is separated from a glass melt flow, and the press molding preform comprised of the optical glass is formed with the prescribed weight. In the method of manufacturing an optical element, the press molding preform or the press molding preform manufactured by the above method is heated and precision press molded.
Abstract:
Provided is an apparatus for forming glass elements, which includes top and bottom die assemblies, each of the die assemblies comprising a core mold, a mold die which supports the core mold, and a die plate, and a glass material being interposed between the top and bottom core molds, a first fastening member, which fastens the mold die and bottom die plate of the bottom die assembly together, a second fastening member, which fastens the die plate of the bottom die assembly and the heat insulating cylinder together, a third fastening member, which fastens the mold die and die plate of the top die assembly together, and a fourth fastening member, which fastens the die plate of the top die assembly and the heat insulating cylinder together. Each of the first to fourth fastening members is made of a material selected from the group consisting of carbon and molybdenum.
Abstract:
An array of optical microelements is produced by press molding, at a high temperature, a transparent glass with a press mold which has a molding surface formed into a shape corresponding to the optical microelement array and coated with a chemically stable thin film.
Abstract:
According to a method of molding a glass body, a glass preform is placed between upper and lower molds of a mold assembly. The mold assembly is then heated to a predetermined heating temperature falling within a heating temperature range corresponding to a glass viscosity range of the glass preform of 10.sup.8 to 10.sup.10.5 poise. A pressure high enough to mold the glass preform is applied between the upper and lower molds when the glass preform is at the predetermined heating temperature, so that an unfinished glass molded body is formed. The pressure is released, and the unfinished glass molded body and the mold assembly are gradually cooled to a temperature within a glass viscosity range of 10.sup.11.5 to 10.sup.14 poise while the unfinished glass molded body is held in the mold assembly. A glass molded body is then released from the mold assembly.