Abstract: Provided is a high refractive index glass, comprising, as a glass composition in terms of mass %, 0 to 10% of B2O2, 0.001 to 35% of SrO, 0.001 to 30% of ZrO2+TiO2, and 0 to 10% of La2O2+Nb2O5, having a mass ratio of BaO/SrO of 0 to 40 and a mass ratio of SiO2/SrO of 0.1 to 40, and having a refractive index nd of 1.55 to 2.3.

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: An optical glass contains a substance A generating light of a wavelength ?2 when irradiated with light of a wavelength ?1 and a substance B generating light of a wavelength ?3 when irradiated with light of the wavelength ?1 when a relation between the wavelength ?1 and the wavelength ?2 and the wavelength ?3 is assumed to be ?1<?2<?3 with respect to 100% of basic glass composition containing 2-10% of SiO2, 5-45% of B2O3, and 30-60% of La2O3 or further containing 0-15% of RO(R=Zn, Sr, Ba), 0-40% of Ln2O3(Ln=Y, Gd), and 0-30% of ZrO2+Nb2O5+Ta2O5, and the substance B generates fluorescent light with the wavelength ?3 of 650 nm or more when excited at the wavelength ?1 of 550 nm or less.

Abstract: An optical Glass characterized by comprising, denoted as molar percentages: B2O5—5 to 45 percent; SiO2—0 to 6 percent (excluding 6 percent); Li2O, Na2O, K2O in total—0 to 3 percent; ZnO—10 to 40 percent; La2O3—5 to 30 percent; Gd2O3—1 to 20 percent; and ZrO2, TaO2, TiO2, Nb2O5, WO3, and Bi2O3 in total—2.5 to 20 percent. The cation ratio of the Ti4+ content relative to the total content of Zr4+, Ta5+, Ti4+, Nb5+, W6+, and Bi3+ is 0.30 or lower; in that the temperature Tp at which a viscosity of 107.2 dPa·s is exhibited is 706° C. or lower. The refractive index nd and the Abbé number v(nu)d satisfy all of the following relations (I) to (IV): 34.0?vd<40 (I); nd?1.87 (II); nd?2.245?0.01×vd (III) and nd?2.28?0.01×vd (IV).

Abstract: An optical glass includes, by mass: 38 to 55% of P2O5; 1 to 10% of Al2O3; 0 to 5.5% of B2O3; 0 to 4% of SiO2; 3 to 24.5% of BaO; 0 to 15% of SrO; 1 to 10% of CaO; 0.5 to 14.5% of ZnO; 1 to 15% of Na2O; 1 to 4% of Li2O; 0 to 4.5% of K2O; 0 to 0.4% of TiO2; and 0 to 5% of Ta2O5, in which BaO+SrO+CaO+ZnO falls within a range of 25 to 39%, Na2O+Li2O+K2O falls within a range of 5 to 20%, Al2O3+SiO2+CaO+Ta2O5 falls within a range of 9 to 18% and P2O5+B2O3+Al2O3+SiO2+BaO+SrO+CaO+ZnO+Na2O+Li2O+K2O+TiO2+Ta2O5 is equal to 98% or more.

Abstract: An optical glass comprising, by mass %, 12 to 30% of total of B2O3 and SiO2, 55 to 80% of total of La2O3, Gd2O3, Y2O3, Yb2O3, ZrO2, Nb2O5 and WO3, 2 to 10% of ZrO2, 0 to 15% of Nb2O5, 0 to 15% of ZnO and 0% or more but less than 13% of Ta2O5, wherein the ratio of the content of Ta2O5 to the total content of La2O3, Gd2O3, Y2O3, Yb2O3, ZrO2, Nb2O5 and WO3 is 0.23 or less, the ratio of the total content of La2O3, Gd2O3, Y2O3 and Yb2O3 to the total content of B2O3 and SiO2 is from 2 to 4, the optical glass having a refractive index nd of 1.86 or more and an Abbe's number ?d of 38 or more, and a rod-shaped glass shaped material and an optical element formed of the above optical glass each.

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: An optical glass includes a substance A generating light of a wavelength ?2 when irradiated with light of a wavelength ?1 and a substance B generating light of a wavelength ?3 when irradiated with light of the wavelength ?1 in the case where the relation between the wavelength ?1, the wavelength ?2, and the wavelength ?3 is assumed to be ?1<?2<?3 with respect to a 100% of basic glass composition containing at least, 2-20% SiO2, 5-45% B2O3, and 10-29% La2O3, by weight, or with respect to a 100% of basic glass composition containing; at least, 2-20% SiO2, 5-45% B2O3, 10-29% La2O3, 0-45% RO (R=Zn, Sr, Ba), 0-10% Ln2O3 (Ln=Y, Gd), and 1-20% total of ZrO2+Nb2O5+TiO2+Ta2O5, by weight.

Abstract: An optical glass having a high refractive index (particularly preferably a refractive index of 1.6 or more), low dispersion (an Abbe number of 45 or more), a low deformation point, and improved resistance to devitrification upon molding, and suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure is provided. The optical glass contains 1.0-4.5 wt. % SiO2, 30.5-50.0 wt. % B2O3, 1.1-8.0 wt. % Li2O, 10.1-19.5 wt. % BaO, 15.5-30.0 wt. % ZnO, 3.0-15.0 wt. % Y2O3, and 10.0-19.5 wt. % La2O3.

Abstract: An aspect of the present invention relates to optical glass, which is oxide glass comprising various cationic components in prescribed amounts without Pb, with a refractive index nd of 1.750 to 1.850, an Abbé number ?d of 29.0 to 40.0, and a glass transition temperature of less than 630° C.

Abstract: The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

Abstract: A housing/enclosure/cover can include an ion-exchanged glass exhibiting the following attributes (1) radio, and microwave frequency transparency, as defined by a loss tangent of less than 0.03 and at a frequency range of between 15 MHz to 3.0 GHz; (2) infrared transparency; (3) a fracture toughness of greater than 0.6 MPa·m1/2; (4) a 4-point bend strength of greater than 350 MPa; (5) a Vickers hardness of at least 450 kgf/mm2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (6) a Young's Modulus ranging between about 50 to 100 GPa;; (7) a thermal conductivity of less than 2.0 W/m° C., and (9) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

Abstract: A fluorophosphate glass containing: P5+ in an amount of 20 to 45 cationic %; Al3+ in an amount of 15 to 35 cationic %; Ba2+ in an amount of 20 to 50 cationic %; B3+ in an amount of 0 to 5 cationic %; F? in an amount of 20 to 50 anionic %; and O2? in an amount of 50 to 80 anionic %. A molar ratio of O2?/P5+ is greater than or equal to 3.5. In addition, a molar ratio of Al3+/P5+ is less than or equal to 1. In addition, the Abrasion FA is less than or equal to 600, or the Knoop hardness number is greater than or equal to 300 MPa. Furthermore, the Abbe number (?d) of the glass is larger than or equal to 66. Moreover, a refractive index (nd) of the glass satisfies an expression (1): nd?2.0614?0.0071×?d.

Abstract: An optical glass is provided that includes a refractive index (nd) of no less than 1.75 and an Abbe number (vd) of no less than 10 as optical constants. A Bi2O3 content is no less than 10% by weight to no more than 80% by weight. The content of SiO2 is lower than the content of B2O3. The total content of SiO2+B2O3 is from no less than 1% by weight to no more than 60% by weight. The content of RO is from no less than 0.1% by weight to no more than 50% by weight. R represents one or more elements selected from the group consisting of Zn, Ba, Sr, Ca, and Mg. The optical glass has at least one of the properties of being substantially free from opacification and/or being substantially devitrified within the glass body under the conditions of a reheating testing.

Abstract: An optical class comprising, by mass %, 12 to 30% of total of B2O3 and SiO2, 55 to 80% of total of La2O3, Gd2O3, Y2O3, ZrO2, Nb2O5 and WO3, 2 to 10% of ZrO2, 0 to 15% of Nb2O5, 0 to 15% of ZnO and 0% or more but less than 13% of Ta2O5, wherein the ratio of the content of Ta2O5 to the total content of La2O3, Gd2O3, Y2O3, Yb2O3, ZrO2, Nb2O5 and WO3 is 0.23 or less, the ratio of the total content of La2O3, Gd2O3, Y2O3 and Yb2O3 to the total content of B2O3 and SiO2 is from 2 to 4, the optical glass having a refractive index nd of 1.86 or more and an Abbe's number ?d of 38 or more, and a rod shaped glass shaped material and an optical element formed of the above optical glass each.

Abstract: An optical glass composition contains, in % by mole, 0% or more and 25.0% or less of SiO2, 20.0% or more and 40.0% or less of B2O3, 0% or more and 5.0% or less of Li2O, 3.0% or more and 15.0% or less of ZnO, 0% or more and 10.0% or less of ZrO2, 2.0% or more and 7.0% or less of Ta2O5, 6.0% or more and 25.0% or less of La2O3, 5.0% or more and 22.0% or less of Gd2O3, 66.5% or less of La2O3+Gd2O3+B2O3 and 26.0% or more of La2O3+Gd2O3, and has nd of 1.83 or higher and 1.86 or lower, vd of 43 or higher and 46 or lower and a liquidus temperature of 1300° C. or lower, and a preform and an optical element are formed from the optical glass composition.

Abstract: The invention relates to a composition comprising mica and glass, said glass comprising: 10 to 30 mol % of SiO2 5 to 40 mol % of BaO 15 to 30 mol % of B2O3, the sum of the concentrations of zinc oxide, alkali metal oxide and alkaline earth oxide in the glass extending from 15 to 65 mol %. This composition is intended to be molded at a temperature above the Tg of the glass so as to form composite parts that can serve as an electrical insulator.

Abstract: A cover glass, containing, by mole percentage: 15 to 40% of P2O5; 15 to 30% of Al2O3; 0 to 15% of SiO2; 0 to 20% of B2O3; 0 to 10% of Li2O; 0 to less than 20% of Na2O; 0 to less than 20% of K2O, provided that Li2O+Na2O+K2O is in a range from 15 to less than 20%; and from 1 to 35% of MgO+CaO+SrO+ZnO. The cover glass being suitable for at least one selected from the group consisting of a solid-state imaging element package and an air-tight sealing of a resin package, and having a sufficient strength not to undergo breakage even when subjected to external force.

Abstract: A high-refractive index, low-dispersion optical glass which is small in a change of imaging properties due to a change in temperature of the use environment, specifically one capable of realizing an absolute value of multiplication (?×?) of an average coefficient of linear expansion (?) at from ?30 to +70° C. and a photoelastic constant (?) at a wavelength of 546.1 nm of not more than 130×10?12° C.?1×nm×cm?1×Pa?1, is manufactured without using large qualities of components which are high in an environmental load and scarce mineral resources. The optical glass of the invention has an absolute value of multiplication (?×?) of an average coefficient of linear expansion (?) at from ?30 to +70° C. and a photoelastic constant (?) at a wavelength of 546.1 nm of not more than 130×10?12° C.?1×nm×cm?1×Pa?1; and contains more than 0% of SiO2, B2O3 and La2O3, more than 13% and less than 20% of (ZrO2+Nb2O5) and less than 2.0% of ZnO in terms of % by mass on the oxide basis.

Abstract: Provided is an optical glass having optical constants, a refractive index (nd) of more than 1.9 and an Abbe number (?d) of not more than 38, having a small partial dispersion ratio and capable of being produced from inexpensive materials. The optical glass has a partial dispersion ratio (?g, F) of at most 0.615, and contains, as indispensable ingredients, B2O3, La2O3, TiO2, Nb2O5 and Ta2O5, wherein the ratio, as % by mass, of TiO2/Nb2O5 is at most 0.26 and GeO2/Nb2O5 is at most 0.38. The optical glass contains, in terms of % by mass, the following ingredients: B2O3 ??5 to 22%, La2O3 ??15 to 50%, TiO2 0.01 to 15%, Nb2O5 ??5 to 40%, and Ta2O5 ?0.1 to 25%, and SiO2 0 to 10% and/or GeO2 0 to 10% and/or Al2O3 0 to 10% and/or Gd2O3 0 to 16% and/or ZrO2 0 to 15% and/or WO3 0 to 22% and/or Sb2O3 0 to 1%.

Abstract: A compositional range of high strain point alkali metal free, silicate, aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates for photovoltaic devices, for example, thin film photovoltaic devices such as CIGS photovoltaic devices. These glasses can be characterized as having strain points ?570° C., thermal expansion coefficient of from 5 to 9 ppm/° C.

Abstract: The invention provides a novel optical glass which has a refractive index (nd) of 1.78 to 2.2 and an Abbe value (?d) of 16 to less than 40 and is suitable for precision mold press molding by virtue of its having a low glass transition temperature, namely, an optical glass which contains by mole in terms of oxides 25 to 60% B2O3, 2 to 45% (in total) TiO2 and Nb2O5 and 1 to 25% WO3 and has a refractive index (nd) of 1.78 to 2.2 and an Abbe value (?d) of 16 to less than 40. Further, the glass contains 5 to 35% La2O3 and 1 to 40% ZnO and has a glass transition temperature (Tg) of 700° C. or below. The optical glass is excellent in meltability, stability and devitrification resistance and has a high refractive index, high light-dispersive power and excellent precision press moldability.

Abstract: A lead-free glass for covering electrodes including, as represented by mass % based on the following oxides, from 30 to 50% of B2O3, from 21 to 25% of SiO2, from 10 to 35% of ZnO, from 7 to 14% in total of K2O and either one or both of Li2O and Na2O, from 0 to 10% of Al2O3, and from 0 to 10% of ZrO2, wherein when it contains at least one component selected from the group consisting of MgO, CaO, SrO and BaO, the total of their contents is at most 5%, and when the molar fractions of Li2O, Na2O and K2O are represented by l, n and k, respectively, l is at most 0.025, and l+n+k is from 0.07 to 0.17.

Abstract: An optical glass includes a substance A generating light of a wavelength ?2 when irradiated with light of a wavelength ?1 and a substance B generating light of a wavelength ?3 when irradiated with light of the wavelength ?1 in the case where the optical glass includes 5-50 ppm Fe with respect to a 100% basic glass composition containing at least, 2-10% SiO2, 5-45% B2O3, and 30-60% La2O3, by weight, or the relation of the wavelength ?1, the wavelength ?2, and the wavelength ?3 is assumed to be ?1<?2<?3 with respect to a 100% basic glass composition containing; at least, 2-10% SiO2, 5-45% B2O3, 30-60% La2O3, 0-15% RO (R=Zn, Sr, Ba), 0-40% Ln2O3 (Ln=Y, Gd), and 0-30% total of ZrO2+Nb2O5+Ta2O5, by weight.

Abstract: The lead- and arsenic-free optical glass has a refractive index nd of 1.55?nd?1.64, an Abbe number ?d of 42??d?65, and a low transition temperature Tg?460° C., good producibility and processability, and crystallization stability. The optical glass has a composition within the following range, in wt. % based on oxide content: P2O5 40-58 ZnO 20-34 Li2O 0.5-5?? GeO2 0.1-11. The glass may also have a total content of SiO2, B2O3 and Al2O3 that is less than 9 wt. %. The glass may contain MgO, SrO, CaO and BaO, but the sum of these oxides is preferably at least 2 wt. % and at most 12 wt. %. The glass may contain at most 5 wt. % of each of La2O3, TiO2, Nb2O5, at most 2 wt. % Ta2O5 and less than 1 wt. % fluorine.

Abstract: An optical glass having refractive index (nd) exceeding 1.85, Abbe number (?d) of 36 or over, comprising SiO2, B2O3, La2O3, Gd2O3, Ta2O5 and Li2O as essential components, being free of Pb and As components, and having glass transition temperature (Tg) of 630° C. or below.

Abstract: An optical glass of the present invention has optical constants of a refractive index (nd) within a range from 1.75 to 1.85 and an Abbe number (?d) within a range from 35 to 45, comprises SiO2 and B2O3 as essential components and one or more components selected from the group consisting of ZrO2, Nb2O5, Ta2O5 and WO3, has a glass transition temperature (Tg) of 580° C. or below and has weathering resistance (surface method) of Class 1 or Class 2.

Abstract: A high-refractivity low-dispersion optical glass that can be stably supplied and has excellent glass stability and that has coloring reduced, comprises, by mass %, 5 to 32% of total of SiO2 and B2O3, 45 to 65% of total of La2O3, Gd2O3 and Y2O3, 0.5 to 10% of ZnO, 1 to 20% of total of TiO2 and Nb2O5, 0 to 15% of ZrO2, 0 to 2% of WO3, 0 to 20% of Yb2O3, 0 to 10% of total of Li2O, Na2O and K2O, 0 to 10% of total of MgO, CaO, SrO and BaO, 0 to 12% of Ta2O5, 0 to 5% of GeO2, 0 to 10% of Bi2O3, and 0 to 10% of Al2O3, wherein the mass ratio of the content of SiO2 to the content of B2O3, (SiO2/B2O3), is from 0.3 to 1.0, and the mass ratio of the total content of Gd2O3 and Y2O3 to the total content of La2O3, Gd2O3 and Y2O3, (Gd2O3+Y2O3)/(La2O3+Gd2O3+Y2O3), is from 0.05 to 0.6, the optical glass having a refractive index nd of 1.89 to 2.0 and an Abbe's number ?d of 32 to 38 and having a coloring degree ?70 of 430 nm or less.

Abstract: An optical glass includes, by weight: 1% or more and 5% or less of silicon oxide (SiO2); 15% or more and 24% or less of boron oxide (B2O3); 0.1% or more and 3% or less of aluminum oxide (Al2O3); 1% or more and 14% or less of zinc oxide (ZnO); 35% or more and 45% or less of lanthanum oxide (La2O3); 5% or more and 10% or less of yttrium oxide (Y2O3); 5% or more and 13% or less of tantalum oxide (Ta2O5); and 0.5% or more and 3% or less of lithium oxide (Li2O).

Abstract: To provide a cover glass for a solid-state imaging element package, which is useful for air-tight sealing of a resin package and which has a strength not to undergo breakage even when subjected to external force. A cover glass for a solid-state imaging element package, which comprises, by mole percentage, P2O5: 15 to 40%, Al2O3: 15 to 30%, SiO2: 0 to 15%, B2O3: 0 to 20%, Li2O: 0 to 15%, Na2O: 0 to 25%, K2O: 0 to 25%, provided that Li2O+Na2O+K2O: 15 to 40%, and MgO+CaO+SrO+ZnO: 1 to 35%.

Abstract: The invention relates to aluminoborosilicate-based glasses suitable for use as a solid laser medium. In particular, these aluminoborosilicate-based laser glasses exhibit broad emission bandwidths of rare earth lasing ions. Although not entirely understood, the broadening of the emission bandwidth is believed to be achieved by the presence of significant amounts of lanthanide ions in the glass matrix. In addition, because of the high values of Young's modulus, fracture toughness and hardness, the rare earth aluminoborosilicate glass system according to the invention is also suitable as transparent armor window material.

Abstract: A glass composition that simultaneously has a low temperature coefficient of refractive index and a good light transmittance, being suitable for use in environments of intense temperature change. There is provided an optical glass containing SiO2, B2O3 and La2O3, which has a temperature coefficient (20° to 40° C.) of relative refractive index (546.07 nm) of 10.0×10?6 (° C.?1) or below. Further, there is provided an optical glass mentioned above having a temperature coefficient (20° to 40° C.) of relative refractive index (546.07 nm) of 4.6×10?6 (° C.?1) or below. Still further, there is provided an optical glass mentioned above having an internal transmittance (?;10 mm) at 400 nm of 80% or higher.

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 glass ceramic composition which is formed by firing into a sintered body having a relatively high relative dielectric constant and Q value is provided. It includes a CaZrO3-based ceramic and a Li2O—MgO—ZnO—B2O3—SiO2-based glass. The Li2O—MgO—ZnO—B2O3—SiO2-based glass is 1 to 12 percent by weight of the total composition, the content of Li2O is 3.5 to 15 percent by weight, the content of MgO is 20 to 50 percent by weight, the content of BaO is 0 to 25 percent by weight, the content of CaO is 0 to 10 percent by weight, the content of SrO is 0 to 25 percent by weight, the content of B2O3 is 16 to 29 percent by weight, the content of SiO2 is 11 to 35 percent by weight, the content of ZnO is 5 to 20 percent by weight, and the content of Al2O3 is 0 to 15 percent by weight. This glass ceramic composition is advantageously used for green glass ceramic layers to form a green laminate structure useful as a main component body of an LC filter or the like.

Abstract: An optical glass having high refractive index and low dispersion properties. There is provided an optical glass having an Abbe number (?d) and a refractive index (nd) in a region indicated by a shape bound by connecting three points, A(53, 1.70), B(53, 1.87), and C(40, 1.87) with straight lines on an orthogonal xy-coordinate system with the x-axis designating the Abbe number and the y-axis designating the refractive index; and comprising no less than 25% and no more than 65% of a combination of a SiO2 component and a B2O3 component, no less than 20% and no more than 55% of a Ln2O3 component (Ln represents at least one species selected from the group consisting of La, Gd, Dy, Yb, and Lu), and a ratio of a La2O3 component to a Ln2O3 component being no more than 0.6, by mol % on the basis of oxides.

Abstract: A glass composition for electrode formation includes, as a glass composition expressed in terms of oxides by mass %, 60 to 90% of Bi2O3, 2 to 25% of B2O3, 0 to 25% of ZnO, 0.01 to 20% of MgO+CaO+SrO+BaO, and 0 to 25% of SiO2.

Abstract: Preforms for precision press molding made of optical glass, optical elements, and methods of manufacturing the same are provided. The preforms are suited to precision press molding having a broad range of dispersion characteristics, a low glass transition temperature, a low sag point, and good resistance to devitrification while containing no PbO. The optical element is obtained by precision press molding the preform. One example of the preform has a refractive index (nd) of greater than or equal to 1.7 and an Abbé number (?d) of less than or equal to 32. The other example of the preform has an Abbé number (?d) exceeding 32.

Abstract: An optical glass having optical constants of a refractive index (nd) of 1.78 or over, an Abbe number (?d) of 30 or below, and a partial dispersion ratio (?g, F) of 0.620 or below comprises SiO2 and Nb2O5 as essential components, wherein an amount of Nb2O5 in mass % is more than 40%. The optical glass further comprising, in mass % on oxide basis, less than 2% of K2O and one or more oxides selected from the group consisting of B2O3, TiO2, ZrO2, WO3, ZnO, SrO, Li2O and Na2O wherein a total amount of SiO2, B2O3, TiO2, ZrO2, Nb2O5, WO3, ZnO, SrO, Li2O and Na2O is more than 90% and TiO2/(ZrO2+Nb2O5) is less than 0.32.

Abstract: The optical glass of the present invention has 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, 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. The present invention further relates to a preform for precision press molding comprised of this glass, an optical element comprised of this glass, and methods of manufacturing the same.

Abstract: The present invention has an object to provide an optical glass which has middle refractive index and low dispersibility, a low yield point (Ts) and a liquidus temperature (L.T.) and excellent weather resistance, and is suitable for mold press molding. The present invention relates to an optical glass comprising, in mass % on oxide basis, SiO2: 20 to 40%, B2O3: 10 to 30%, SrO: 10 to 30%, Al2O3: 5.5 to 15%, La2O3: 0.5 to 11%, Li2O: 3 to 12%, CaO: 0 to 10%, BaO: 0 to 9.5%, and ZnO: 0 to 10%.

Abstract: An optical glass comprises, denoted as weight percentages, SiO2-2-22%, B2O3: 3-24%, ZnO:>8% and ?30%, CaO+BaO+ZnO: 10-50%, MgO: 0-3%, La2O3+Y2O3+Gd2O3+Yb2O3: 1-33%, TiO2: 2-20%, ZrO2: 0-10%, Nb2O5: 2-32%, Li2O: 0-5%, Na2O: 0-8%, K2O: 0-10%, WO3: 0-20%. The ratio by weight of La2O3 to the combined contents of La2O3, Y2O3, Gd2O3, and Yb2O3 (La2O3/(La2O3+Y2O3+Gd2O3+Yb2O3)) falls within a range of 0.7 to 1.

Abstract: The present invention relates to an optical glass, a preform for precision press molding, methods for manufacturing the same, and an image pickup device. The optical glass of the present invention not only has a high refractive index, a high dispersion property, and good precision press moldability, but also has good stability with respect to devitrification when reheated (referred to as “devitrification stability upon reheating”), and is an optical glass with a good partial dispersion ratio (Pg, F).

Abstract: An optical glass having optical constants of a refractive index (nd) of 1.78 or over, an Abbe number (?d) of 30 or below, and a partial dispersion ratio (?g, F) of 0.620 or below comprises SiO2 and Nb2O5 as essential components, wherein an amount of Nb2O5 in mass % is more than 40%. The optical glass further comprising, in mass % on oxide basis, less than 2% of K2O and one or more oxides selected from the group consisting of B2O3, TiO2, ZrO2, WO3, ZnO, SrO, Li2O and Na2O wherein a total amount of SiO2, B2O3, TiO2, ZrO2, Nb2O5, WO3, ZnO, SrO, Li2O and Na2O is more than 90% and TiO2/(ZrO2+Nb2O5) is less than 0.32.

Abstract: The present invention relates to an optical glass having optical constants in the form of a refractive index nd of 1.70 or higher and an Abbé number nud of 50 or higher, a preform for precision press molding comprised of this glass, an optical element comprised of this glass, and methods for manufacturing the preform and the optical element.

Abstract: There is provided an optical glass with a high refractive index and a low dispersion having a refractive index (nd) of not less than 1.75 and an Abbe's number (?d) of not less than 35 where the image formation characteristic is hardly affected by changes in temperature of the using environment. SiO2, B2O3 and La2O3 are contained as essential components and the ratio of the constituting components are adjusted whereby an optical glass in which a product of ? and ? where ? is an average linear expansion coefficient at ?30 to +70° C. and ? is an optical elasticity constant at the wavelength of 546.1 nm is not more than 130×10?12° C.?1×nm×cm?1×Pa?1 is able to be achieved.

Abstract: Optical glass having a refractive index (nd) of 1.85 or greater, and an Abbe number (?d) falling within the range of 10 to 30, which is suited for molding by precision mold press is provided. The optical glass is characterized by including B2O3+SiO2 in an amount of 3 to 60%, Bi2O3 in an amount of 25 to 80%, RO+Rn2O in an amount of 5 to 60% (wherein R represents one or more selected from a group consisting of Zn, Ba, Sr, Ca, and Mg; and Rn represents one or more selected from a group consisting of Li, Na, K, and Cs), with each component in the range expressed in oxide-based mole percentage, and is characterized in that transparency in the visible region is high, and that the transition point (Tg) is 480° C. or lower. The optical glass is characterized by having a spectral transmittance of 70% or greater at a wavelength of 600 nm for a thickness of 10 mm.

Abstract: The optical glasses designated to be used in the areas of imaging, sensors, microscopy, medical technology, digital projection, photolithography, laser technology, wafer/chip technology as well as telecommunications, optical communications engineering and optics/illumination in the automotive sector with a refractive index nd of 1.60?nd?1.72 and/or an Abbe number vd of 32?vd?45 and with a Tg of 567° C. to 640° C., pronounced short flint character, good chemical resistance, excellent resistance to crystallization, good solarization stability and the following composition (in % by weight based on oxides): SiO2 30-45 B2O3 ?8-12 Na2O ?8-15 CaO 0.1-7?? ZnO 0 ? 5 ZrO2 10-20 Nb2O5 12-24 Ta2O5 0 ? 9 AgO ?0 ? 5.

Abstract: A powder composition for forming a highly expansible crystallized glass substantially free of alkali metals is disclosed, which composition can provide, through its firing at a temperature of not more than 900° C., a seal between metal and ceramic. The powder composition is a powder composition for the formation of a sealing crystallized glass which is substantially free of alkali metals and consists of the powder of a glass containing, calculated as oxides, SiO2: 10-30% by mass, B2O3: 20-30% by mass, CaO: 10-40% by mass, MgO: 15-40% by mass, BaO+SrO+ZnO: 0-10% by mass, La2O3: 0-5% by mass, Al2O3: 0-5% by mass, and RO2: 0-3% by mass (wherein R represents Zr, Ti, or Sn), wherein the crystallized glass that is formed by firing the powder composition at 900±50° C. has a coefficient of thermal expansion of 90-120×10?7/° C. at 50-550 ° C.

Abstract: Provided is a glass composition for electrode formation including, as a glass composition expressed in terms of oxides by mass %, 73.1 to 90% of Bi2O3, 2 to 14.5% of B2O3, 0 to 25% of ZnO, 0.2 to 20% of MgO+CaO+SrO+BaO (total content of MgO, CaO, SrO, and BaO) , and 0 to 8.5% of SiO2+Al2O3 (total content of SiO2 and Al2O3).

Abstract: A high-refractivity optical glass which has both a low-temperature softening property suitable for precision press-molding and glass stability suitable for hot-shaping of a preform, which contains, by mass %, 13 to 30% of B2O3, 0.1 to 4% of Li2O, 17 to 35% of ZnO, 15 to 45% of La2O3, 4 to 15% of Ta2O5 exclusive of 15%, 0 to 10% of ZrO2, 0 to 10% of Nb2O5 provided that Ta2O5/(Ta2O5+ZrO2+Nb2O5)>0.3, 0 to 20% of WO3 and 0 to 1% of Sb2O3 and which has a refractive index (nd) of 1.80 to 1.84 and an Abbe's number (?d) of 40.0 to 45.0.