Abstract: A manufacturing method of a glass substrate for magnetic disk including a pair of principal surfaces is disclosed The method includes the steps of: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by sandwiching simultaneously the lump from both sides of the dropping path of the lump with surfaces of the pair of dies facing together, and performing press forming to the lump; and machining process for machining the sheet glass material, wherein the press forming sandwiches the lump while moving the pair of dies in the direction of drop of the lump so that relative speed of the lump to that of the pair of dies approaches zero.

Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.

Abstract: A lens system having an infrared filter for a compact camera module is provided. The lens system is an achromatic lens system and has two lenses. The first lens has a positive focal length, and the second lens has a negative focal length. The first lens is made of copper ion containing glass which absorbs infrared light and functions as an infrared filter. The second lens has an Abbe number that is smaller than that of the first lens with a difference between the Abbe numbers of the first lens and the second lens being at least 15.

Abstract: To provide a process for producing glass raw material granules which are less likely to be formed into fine powders which cause a change of the glass composition at a time of forming a glass melt or defects of glass, and which can be preferably used for producing glass. A process for producing glass raw material granules, which comprises a granulation step of adding boric acid to either one of or both of a glass raw material powder and an alkaline solution having a pH of at least 9 and mixing the glass raw material powder together with the alkaline solution. The glass raw material powder preferably contains at least 10 mass % of boric acid.

Abstract: A sputtering target comprises a low Tg glass or an oxide of copper or tin. Such target materials can be used to form mechanically-stable thin films that exhibit a self-passivating phenomenon and which can be used to seal sensitive workpieces from exposure to air or moisture. Low Tg glass materials may include phosphate glasses such as tin phosphates and tin fluorophosphates, borate glasses, tellurite glasses and chalcogenide glasses, as well as combinations thereof.

Abstract: Objective of the present invention is to provide a glass melting furnace, a process for modifying a glass melt and a process for producing glass melt, whereby composition-modified glass melt containing an additive component at a high concentration can be produced with an excellent quality. The glass melting furnace 10 of the present invention is a glass melting furnace 10 for adding an additive to a molten state glass to form composition-modified glass melt, discharging the composition-modified glass melt, and a forehearth 20, said forehearth comprising a feed portion to feed an additive, and a heating means to form a heating gas phase portion above the liquid surface of the glass melt to convert the additive from the feed portion into melted particles of additive below the feed portion.

Abstract: A solar concentrator includes a solid body of a transparent material, which comprises a light coupling-in surface and a light coupling-out surface. A supporting frame and a light-transmitting part are located between the light coupling-in surface and the light coupling-out surface.

Abstract: A source material, which is based on a glass, is arranged on a working surface of a mold substrate. The mold substrate is made of a single-crystalline material. A cavity is formed in the working surface. The source material is pressed against the mold substrate. During pressing a temperature of the source material and a force exerted on the source material are controlled to fluidify source material. The fluidified source material flows into the cavity. Re-solidified source material forms a glass piece with a protrusion extending into the cavity. After re-solidifying, the glass piece may be bonded to the mold substrate. On the glass piece, protrusions and cavities can be formed with slope angles less than 80 degrees, with different slope angles, with different depths and widths of 10 micrometers and more.

Abstract: Computer-implemented methods and apparatus are provided for predicting/estimating chemical depth of layer (DOL) and maximum surface compressive stress (CS) of glass articles after ion-exchange. The methods and apparatus can, for example, be used to select glass compositions, salt bath temperatures, and/or ion-exchange times which provide desired DOL and/or CS values. One or more manufacturing constraints, e.g., constraints on liquidus viscosity, zircon breakdown viscosity, and the like, can be applied to the process of predicting/estimating DOL and/or CS values so that glass compositions selected based on DOL and/or CS values can, for example, be manufactured commercially by a fusion or float process.

Abstract: Titanium oxide containing borosilicate glasses, which have been produced without the use of arsenic and antimony compounds, are provided. An environmentally friendly refining method for providing titanium oxide containing borosilicate glass is also provided. The method includes using oxygen containing selenium compounds as refining agents to provide glasses with good transmittance values in the infrared range and show no disturbing discolorations. The glasses of the present disclosure are particularly suitable for the production of IR light conductors, cover glasses for photo sensors, and UV filters.

Abstract: In one aspect, there is provided a process for manufacturing a lower mold for receiving a falling molten glass droplet, in which without narrowing the option for material for a lower mold, any occurrence of air retention can be favorably prevented and a lower mold excelling in durability can be obtained. The process comprises the film forming step of forming a coating layer on a base material and the surface roughening step of roughening the surface of the coating layer. Preferably, the coating layer contains at least one element selected from among chromium, aluminum and titanium.

Abstract: An optical glass that is an oxide glass having a very high refractive index in spite of its low-dispersion property, having excellent glass stability and having less susceptibility to coloring.

Abstract: A gyroscope having a resonator, a plurality of electrodes located around the resonator, and a thin gap being located between the resonator and the plurality of electrodes. The resonator is axi-symmetric and may be at least partially torroidal in shape or composed of concentric rings. Piezoelectric electrodes or transduction may be used to drive or detect displacements of the resonator. The resonator may be fabricated using a fused silica flowing process.

Abstract: This invention relates to a vacuum degassing vessel wherein even if bubbles of molten glass come into contact with an inner wall of an upper space of a vacuum degassing vessel to produce a molten glass flowing along the inner wall, a molten glass can be discharged to the outside of the vacuum degassing vessel, thereby performing vacuum degassing without deteriorating composition homogeneity of the molten glass.

Abstract: An optical glass that is an oxide glass and comprises, by cationic %, 20 to 40% of a total of Si4+ and B3+, 15 to 40% of a total of Nb5+, Ti4+, W6+ and Zr4+, 0.2 to 20% of a total of Zn2+, Ba2+, Sr2+ and Ca2+, and 15 to 55% of a total of Li+, Na+ and K+, the cationic ratio of the content of B3+ to the total content of B3+ and Si4+ being 0.01-0.5, the cationic ratio of the content of Zr4+ to the total content of Nb5+, Ti4+, W6+ and Zr4+ being 0.05 or less, the molar ratio of the total content of Zn2+ and Ba2+ to the total content of Zn2+, Ba2+, Sr2+ and Ca2+ being 0.8-1, the optical glass having a refractive index nd of 1.815 or more and an Abbe's number ?d of 29 or less.

Abstract: A crystalline silicon ingot and a method of fabricating the same are disclosed. The crystalline silicon ingot of the invention includes multiple silicon crystal grains growing in a vertical direction of the crystalline silicon ingot. The crystalline silicon ingot has a bottom with a silicon crystal grain having a first average crystal grain size of less than about 12 mm. The crystalline silicon ingot has an upper portion, which is about 250 mm away from said bottom, with a silicon crystal grain having a second average crystal grain size of greater than about 14 mm.

Abstract: Arnold (13) includes a recessed portion (21) for receiving a melt (2). The recessed portion (21) is constituted by an inner wall surface (29) for converting the melt (2) into a solidified portion when the inner wall surface (29) contacts the melt (2), and opens in a withdrawal direction (D1) of the solidified portion. A curved line formed by a first contour (23p) and a second contour (25p) has a cusp at a position of start points (43 and 45). The distance between the first contour (23p) and the second contour (25p) in a width direction (D2) increases continuously from an upstream side to a downstream side of the withdrawal direction (D1). The shape of the inner wall surface (29) of the recessed portion (21) is determined so that a cast rod (3) can be rotationally displaced clockwise or counterclockwise about an axis passing through a first end point (33) or a second end point (35) and perpendicular to a section of the mold 13.

Abstract: A process of producing high-purity silicon includes providing silicon-containing powder, feeding the silicon-containing powder into a gas stream, where the gas has a temperature sufficiently high to convert particles of metallic silicon from a solid state into a liquid and/or gaseous state, collecting and, optionally, condensing the liquid and/or gaseous silicon formed, and cooling the collected liquid and/or condensed silicon in a casting mold,

Abstract: The invention relates to red-dyed glass, comprising the components of a base glass, coloring additives, reductants, and stabilizers, wherein the coloring additives comprise copper oxides and neodymium oxides and wherein the reductants comprise tin oxides and wherein the stabilizers comprise antimony oxides, wherein the fraction of the copper oxides in the red-dyed glass is between 0.02 and 0.08 weight percent.

Abstract: An optical glass having a refractive index nd of 1.70 or greater and an Abbé number of 50 or greater. Given as mole percentages, it comprises: B2O3 (20 to 80 percent), SiO2 (0 to 30 percent), Li2O (1 to 25 percent), ZnO (0 to 20 percent), La2O3 (4 to 30 percent), Gd2O3 (1 to 25 percent), Y2O3 (0 to 20 percent), ZrO2 (0 to 5 percent), MgO (0 to 25 percent), CaO (0 to 15 percent), and SrO (0 to 10 percent), with the combined quantity of the above components being 97 percent or greater. The molar ratio of {ZnO/(La2O3+Gd2O3+Y2O3)} is 0.8 or less and the molar ratio of {(CaO+SrO+BaO)/(La2O3+Gd2O3+Y2O3)} is 0.8 or less. Ta2O5 may be incorporated as an optional component, with the molar ratio {(ZrO2+Ta2O5)/(La2O3+Gd2O3+Y2O3)} being 0.4 or less.

Abstract: This invention provides a molding die in which increase of the surface roughness due to crystal growth of chromium oxide is restrained, and thereby allowing long term use without deteriorating surface roughness of a glass gob or a molded glass article. The invention also provides a method for manufacturing the molding die, a glass gob, and a molded glass article. A molding die is provided with a substrate having a molding surface and protective film containing chromium formed thereon, and the protective film has the X-ray diffraction peak intensity of (110) plane of chromium higher than the X-ray diffraction peak intensity of (200) plane.

Abstract: New and improved compositions of doped fluorophosphate glasses for lasers have a high refractive index (nD) of approximately 1.6 to 1.7, high transmission in the near infrared part of the spectrum and a wide glass forming domain. These glass systems, Ba(PO3)2—Al(PO3)3—BaF2-Dopants, utilize dopants from the group of oxides or fluorides of the rare earth elements Sm, Eu, Nd, Er, Yb, Tm, Tb, Ho and Pr as well as MnO; and mixtures thereof. The composition of glass includes chemical durability, efficiency of laser use in the infrared spectrum and improved duration of luminescence.

Abstract: A glass container and related methods of manufacturing. The glass container has a glass composition including soda-lime base glass materials, and an oxide of vanadium for good ultraviolet light blocking properties and an oxide of selenium to decolor the glass for good clarity and decolorization. The glass composition of the glass container also may include an oxide of sulfur.

Abstract: Provided are a process for the production of a precision press-molded article having a high transmittance a method of treating a glass to color or decolor the glass, the process comprising heat-treating a press-molded article containing at least one selected from WO3, Nb2O5 or TiO2 in an oxidizing atmosphere to produce a glass molded article, and the method comprising heat-treating a colored glass containing at least one oxide of WO3 and Nb2O5 in an oxidizing atmosphere to decolor the glass, or heat-treating a glass containing at least one oxide selected from WO3, Nb2O5 or TiO2 in a non-oxidizing atmosphere to color the glass.

Abstract: New and improved compositions of doped fluorophosphate glasses for lasers have a high refractive index (nD) of approximately 1.6 to 1.7, high transmission in the near infrared part of the spectrum and a wide glass forming domain. These glass systems, Ba(PO3)2—Al(PO3)3—BaF2-Dopants, utilize dopants from the group of oxides or fluorides of the rare earth elements Sm, Eu, Nd, Er, Yb, Tm, Tb, Ho and Pr as well as MnO; and mixtures thereof. The composition of glass includes chemical durability, efficiency of laser use in the infrared spectrum and improved duration of luminescence.

Abstract: There is provided a one-press method for producing a glass vessel, the method enabling efficient production of even a glass vessel having the maximum thick wall part having a thickness larger than a predetermined value by using a divided type forming mold having a specific parting line.

Abstract: A method for manufacturing a lens unit including the steps of: forming a first lens array, having plural first lens sections and first reference surfaces formed in a predetermined arrangement, via glass forming by arranging a glass material between a first assembled molds and by clamping the molds; forming a second lens array, having plural second lens sections and second reference surfaces formed in a predetermined arrangement, via glass forming by arranging a glass material between a second assembled molds and by clamping the molds; forming a third lens array by stacking and bonding the first and second lens arrays so that an optical axis of each lens section of the first and second lens arrays coincide, by using the first and second reference surfaces; and cutting the third lens array into each lens unit which includes at least each one of the first and the second lens sections.

Abstract: A method and apparatus for melting a raw material such as glass. The method comprises a creating a flow of raw material interrupted by a heated phase separation barrier (3,31,32), wherein melting is achieved by transfer of heat from the phase separation barrier to the raw material. The process comprises: providing solid raw material to the phase separation barrier, wherein the phase separation barrier supports the solid raw material; heating the phase separation barrier to a temperature which is (a) at least 700° C. and (b) sufficient to cause melting of the solid raw material which contacts the barrier, wherein any melted raw material formed on contact with the phase separation barrier flows off or through the phase separation barrier; and collecting the melted raw material; wherein the phase separation barrier causes separation of the solid and melted phases within the flow of the raw material.

Abstract: A method for manufacturing glass containing a component(s) from Bi3+, Ti4+, Nb5+, and W6+, permitting stable production of high-quality glass with little coloration. A molten glass is contained in a container and is brought into contact with an electrode, a potential is applied so that the electrode serves as an anode and the container coming into contact with the molten glass serves as a cathode. The electrode has a standard electrode potential greater than that of the container. A voltage is applied between the cathode and the anode, with the value of the potential at which the current flowing between the cathode and anode essentially goes to zero as the upper limit thereof, to inhibit corrosion of the container. Further provided are methods of manufacturing a glass material for press molding and an optical element from the glass prepared by the above method.

Abstract: A sealing apparatus for use in conveying molten glass from a first vessel to a second vessel, wherein at least a portion of the first vessel is nested within the second vessel without contact between the first and second vessels, and a flexible member comprising a gas-tight seal separates an atmosphere enclosed by the sealing apparatus and an ambient atmosphere. The sealing apparatus is useful for flexibly sealing a non-contact joint between conduits for supplying molten glass to a forming body.

Abstract: A fluorophosphate glass having a fluorine content of 25% or more by anionic %, which is produced from a glass raw material containing 0.1 to 0.5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine, and a phosphate glass having a fluorine content of less than 25% by anionic %, which is produced from a glass raw material containing 0.1 to 5%, by anionic %, of a halide containing a halogen element selected from chlorine, bromine or iodine.

Abstract: Provided are an apparatus and method of extracting a silicon ingot. The apparatus for extracting a silicon ingot includes a chamber in which a silicon source material introduced into a cold crucible is melted, a primary extraction apparatus vertically movably installed in the chamber and configured to solidify the molten silicon to extract the silicon ingot, a movable apparatus configured to horizontally move the primary extraction apparatus, and a secondary extraction apparatus vertically movably installed under the chamber and configured to extract the silicon ingot in a state in which the primary extraction apparatus is moved to one side. Therefore, as the height of the extraction apparatus is reduced, manufacturing cost of equipment can be reduced and installation space of the extraction apparatus can also be reduced.

Abstract: To provide a method whereby it is possible to produce an alkali-free glass having little bubbles therein and excellent in homogeneity and flatness. A method for producing an alkali-free glass, which comprises melting a glass raw material containing a silicon source, followed by forming, wherein as the silicon source, a silica sand is used which has a median particle diameter D50 of from 20 ?m to 80 ?m and which contains particles having a particle diameter of at most 2 ?m at a ratio of at most 0.3 vol % and particles having a particle diameter of at least 100 ?m at a ratio of at most 2.5 vol %.

Abstract: Castable silicon-based compositions have enhanced toughness and related properties compared to silicon. The con-based compositions comprise silicon at a concentration greater than 50% by weight and one or more additional elements in structure comprising a cubic silicon phase and an additional phase which may impart toughness through mechanisms related to plastic flow or crack interaction with interfacial boundaries.

Abstract: Glass raw material particles are dropped from an oxygen combustion burner 24, and the glass raw material particles are heated by a flame F of an oxygen combustion burner 24 and a thermal plasma P, to melt the particles. Liquid glass particles 30 produced by the melting fall downwardly in a melting tank 12, and fall on a surface of a molten glass liquid G in the melting tank 12. Then, an upper layer G1 of the molten glass liquid G is heated by electrodes 40, 40 of a heating apparatus 38 provided in the melting tank 12. By this method, air and residual gas generated in the molten glass liquid G and the liquid glass particles 30 fallen onto the surface of the molten glass liquid G, become bubbles, surface and are smoothly discharged.

Abstract: Disclosed is a mold for glass substrate molding, which enables to produce a glass substrate having high flatness by a method for producing a glass substrate through press molding of molten glass. Also disclosed is a method for producing a glass substrate by using such a mold. Specifically disclosed is a mold comprising a lower mold having a first molding surface for pressing a molten glass supplied thereto, and an upper mold having a second molding surface for pressing the molten glass against the first molding surface. In the first molding surface, the surface roughness Ra of the peripheral portion which is in contact with the molten glass after pressing is higher than the surface roughness Ra of the central portion which is in contact with the molten glass before pressing.

Abstract: The present invention is directed to a method for making infrared transmitting graded index optical elements by selecting at least two different infrared-transmitting materials, each with a different refractive index, having similar thermo-viscous behavior; assembling the infrared-transmitting materials into a stack comprising one or more layers of each infrared-transmitting material resulting in the stack having a graded index profile; and forming the stack into a desired shape. Also disclosed is the related optical element made by this method.

Abstract: This invention relates to lead free and cadmium free copper-containing glass fits that can be used as pigments to color other glass fits or to impart color to solid substrates such as glass, ceramic or metals, or to impart color to a thermoplastic mass. The compositions comprise silica, alkali metal oxides, alkaline earth metal oxides, tin oxide and copper oxide. The resulting compositions can be used to decorate and protect automotive, beverage, architectural, pharmaceutical and other glass substrates, generally imparting a red color.

Abstract: The invention relates to a known method for drawing a quartz glass cylinder from a melt crucible comprising an inner crucible chamber extending in the direction of a center crucible axis and bounded by a side wall and a floor, wherein SiO2 granulate is fed into the melt crucible and therein softened into a quartz glass mass, and said mass is drawn vertically downward as a cylindrical quartz glass strand by means of a first draw-off device through a first draw nozzle provided in the floor of the melt crucible, and the quartz glass cylinder is cut off therefrom.

Abstract: A glass for a display substrate composed of 50 to 70% SiO2, 10 to 25% Al2O3, 8.4 to 20% B2O3, 0 to 10% MgO, 6 to 15% CaO, 0 to 10% BaO, 0 to 10% SrO, 0 to 10% ZnO, 0 to 5% TiO2, 0 to 5% P2O5, 0.01 to 0.2% alkali metal, and from 0.01% to less than 0.4% ZrO2, as expressed in % by mass. The glass can have a ?-OH value of 0.20/mm or more and an area of 0.1 m2 or more. The glass is produced by mixing raw materials to provide the SiO2, Al2O3, B2O3, MgO, CaO, BaO, SrO, ZnO, TiO2, P2O5 and alkali metal contents, electrically melting the raw materials in a melting furnace constructed of a high zirconia refractory; and refining, homogenizing and forming the glass melt.

Abstract: The present invention provides (i) a process for producing molten glass from glass raw material particles and glass cullet pieces by an in-flight melting method; (ii) a process for producing glass products using the process (i); (iii) a glass melting furnace for carrying out this process (i); and (iv) an apparatus for producing glass products using the melting furnace (iii).

Abstract: A glass-melting furnace, which suppresses the effect of exhaust gas on molten glass quality, a process for producing molten glass, and a process and apparatus for producing glass products. The glass-melting furnace containing: a raw glass material particle feed portion disposed downwardly at a furnace wall portion in an upper portion of the glass-melting furnace; a heating unit provided under the feed portion, which forms a gas phase portion for converting raw glass material particles into liquid glass particles; a flue inlet disposed on the upstream side of the gas phase portion in a flow direction of the molten glass liquid; a furnace-bottom portion, which accumulates the liquid glass particles that produce the molten glass liquid; and a discharge portion, which discharges the molten glass liquid.

Abstract: A fining agent for reducing the concentration of seeds or bubbles in a silicate glass. The fining agent includes at least one inorganic compound, such as a hydrate or a hydroxide that acts as a source of water. In one embodiment, the fining agent further includes at least one multivalent metal oxide and, optionally, an oxidizer. A fusion formable and ion exchangeable silicate glass having a seed concentration of less than about 1 seed/cm3 is also provided. Methods of reducing the seed concentration of a silicate glass, and a method of making a silicate glass having a seed concentration of less than about 1 seed/cm3 are also described.

Abstract: The present invention provides (i) a glass melting furnace, (ii) a process for producing molten glass, (iii) an apparatus for producing a glass product, and (iv) a process for producing a glass product, which are capable of preventing deterioration of the quality of molten glass caused by deposition of particles floating on a wall of the furnace. The melting furnace described herein includes a melting tank in which a flue located substantially at the center of a ceiling wall and a number of first heating units are disposed, such that particles floating in the furnace are suctioned off by a suction power of the flue and discharged from the furnace without being directed to a surrounding furnace wall. This drastically reduces the amount of floating particles deposited on the furnace wall, which prevents damage to the furnace wall and deterioration of the quality of glass produced therein.

Abstract: The present invention provides a process for producing a molten glass which can produce a molten glass having a good quality, a glass-melting furnace, a process for producing glass products and an apparatus for producing glass products. While an oxygen combustion burner 20 is rotated by a motor 38, glass raw material particles (not shown) are dropped into a high-temperature gas phase atmosphere produced by a flame F of the oxygen combustion burner 20, to be changed into liquid glass particles. By rotation of an outlet (nozzle) of the oxygen combustion burner 20, the falling position of the liquid glass particles 26, 26 . . . changes with time. Accordingly, generation of bubbles caused by continuous fall of the liquid glass particles in a particular position on a molten glass liquid surface is prevented. Accordingly, it is possible to produce a molten glass having a good quality with few bubbles.

Abstract: The present invention provides a glass-melting furnace etc. which can maintain homogeneity of molten glass in an apparatus and a process for producing molten glass by melting glass raw material particles and glass cullet pieces. In the present invention, glass raw material particles are dropped from a glass raw material particle heating unit 14 constituted by oxygen combustion burners 34, 34 . . . and a glass raw material particle feed portion, and the glass raw material particles are changed into liquid glass particles 38, 38 . . . in high-temperature gas phases produced by flames 32, 32 . . . of oxygen combustion burners 34, 34 . . . . In the step of heating and melting the glass raw material particles, glass cullet pieces 30, 30 . . . are feed by an feed means 40 of a glass cullet piece feed portion 12 so as to be spread radially toward the plurality of flames 32, 32 . . . around the feed portion.

Abstract: A mold for use in production of a glass optical element includes an upper mold and a lower mold on which a molten glass is dropped, the lower mold being provided with a molding surface for press molding the molten glass with the upper mold. A recess for forming a positioning protrusion on the glass optical element is provided at an outer side of the molding surface. An inclined section is provided at an inner circumferential surface of the recess closer to the molding surface. The inclined section is inclined such that, when the molten glass dropped on the molding surface spreads toward the outer side, the molten glass enters the recess while maintaining contact with the inclined section.

Abstract: A method for manufacturing a glass optical element includes the steps of: feeding molten glass onto a lower mold part; and compression-molding the molten glass using an upper mold part and the lower mold part. The upper mold part is provided with a recess for forming a positioning protrusion of the glass optical element. A surface of the recess includes a first region where a protective film against the molten glass is formed, and a second region where the protective film is not formed and the upper mold part is exposed. In the step of compression-molding the molten glass, after the molten glass enters the recess, the molten glass is compression-molded in a state where a part of the molten glass and the second region do not contact each other, to thereby form the positioning protrusion of the glass optical element.

Abstract: A luminescent borate glass and a preparation method thereof are disclosed. The preparation method includes: weighing raw materials according to a composition of the formula: aM2O.bY2O3.cAl2O3.d B2O3.eSiO2.xCeO2.y Tb2O3, wherein M represents at least one selected element from the group consisting of Na, K, and Li; a, b, c, d, e, x, and y are, by mole parts, 0˜20, 7˜15, 20˜40, 40˜60, 0˜15, 0.1˜1.5, 0.1˜3, respectively; melting the raw materials and then cooling and molding; and heat treating the molded glass to obtain the luminescent borate glass. The luminescent borate glass prepared according to the method has some advantages such as high luminous intensity, uniformity and stability.

Abstract: In a method for producing a fluorophosphate optical glass comprising melting a glass raw material to give a molten glass, and refining, homogenizing and then quickly quenching the molten glass to produce the fluorophosphate optical glass, even if the glass is flown from a refining tank that is set to a high temperature to an operation tank that is set to a low temperature, bubbles are not generated in the glass. The content of Fe in terms of Fe2O3 and the content of Cu in terms of CuO is controlled so that the total of the contents of Fe and Cu is 20 ppm or more, and the obtained fluorophosphate optical glass has such transmittance property that the internal transmittance in terms of a thickness of 10 mm becomes 98% or more at a wavelength region of at least from 400 to 500 nm.