Canon Kabushiki Kaisha

Hoya Corporation

The University of Tokyo

Michio Endo

Kohei Nakata

Shigeru Fujino

Kentaro Doguchi

Hiroyuki Inoue

Kiyoshi Yamamoto

Atsunobu Masuno

Shingo Eguchi

Provided is an optical glass containing glass-forming cations, the optical glass satisfying, expressed in cation percent, 10 cat %&#x2264;B&#x2264;50 cat %, 15 cat %&#x2264;La&#x2264;35 cat %, 20 cat %&#x2264;Nb&#x2264;50 cat %, and 15 cat %&#x2264;Ti&#x2264;25 cat %.

Optical glass, optical element, optical device, method for producing optical glass, and method for producing optical element

An optical glass includes La, Zn, Nb, and Tias a cation configuring glass. La, Zn, Nb, and Tiwhich satisfy 10 cat %&#x2264;La&#x2264;20 cat %, 10 cat %&#x2264;Zn&#x2264;60 cat %, 20 cat %&#x2264;Nb&#x2264;60 cat %, and 0 cat %&#x2264;Ti&#x2264;40 cat % expressed by cation %.

Optical glass, optical element, optical instrument, and method for manufacturing optical glass

An optical glass including B, Laand Nbas cationic components constituting the glass, wherein the optical glass satisfies the following expressions represented in cation percentages:

Optical glass, optical element, and method for manufacturing optical glass

Provided is an optical glass having homogeneous optical characteristics such that striae and devitrification hardly occur at the time of producing a gob. The optical glass includes cationic components having the following composition, provided that a total of the cationic components is 95 cat %, and has a refractive index (nd) of 1.6 or more and less than 1.7 and an Abbe number (vd) of 50 or more and 56 or less, Si3 cat % or more and 13 cat % or less B40 cat % or more and 55 cat % or less La4 cat % or more and 9 cat % or less Ca6 cat % or more and 12 cat % or less Li11 cat % or more and 18 cat % or less Zn6 cat % or more and 12 cat % or less Zr1 cat % or more and 4 cat % or less provided that Si/Bis 0.05 or more and 0.3 or less, and Li/Znis 1.3 or more and 2.0 or less.

Optical material and optical element

An optical element comprising a vacuum-sintered body comprising a plurality of particles each having a two-layer structure comprising a ceramic particle and a coating layer, wherein the ceramic particle comprises LnAlO, where Ln represents a rare-earth element, x represents 1&#x2266;x&#x2266;10, and y represents 1&#x2266;y&#x2266;5, and has an average particle diameter of 1 &#x3bc;m or more and 10 &#x3bc;m or less, and wherein the coating layer comprises a ceramic having a lower sintering temperature than a sintering temperature of the ceramic particle.

An optical element is formed by vacuum-sintering a molded body of ceramic particles having an average particle diameter of 1 &#x3bc;m or more and 10 &#x3bc;m or less and including LnAlO(Ln represents a rare-earth element, 1&#x2266;x&#x2266;10, and 1&#x2266;y&#x2266;5). Ln preferably includes at least one kind selected from La, Gd, Yb, and Lu. The optical element preferably has a refractive index of 1.85 or more and 2.06 or less, and an Abbe number of 48 or more and 65 or less. The obtained optical element has optical properties of high refractive index and low dispersibility.

An optical glass having a remarkably high refractive index and excellent stability can be give without being based on PbO, and the optical glass contains, as essential components, at least one oxide selected from LaO, GdO, YO, YbO, TiO, NbOor WO, at least one oxide selected from MgO, CaO, SrO or BaO and BOand optionally containing SiO, wherein on the basis of mass, the total content of BOand SiOis from 1 to 25%, the ratio of (BO+SiO)/(LaO+GdO+YO+YbO+TiO+NbO+WO) is from 0.05 to 0.3 and the ratio of (MgO+CaO+SrO+BaO)/(LaO+GdO+YO+YbO+TiO+NbO+WO) is from 0.1 to 0.4, the optical glass having a refractive index (nd) of 2.000 or more and an Abbe's number (vd) of 27 or less.

Optical glass, press-molding glass gob and optical element

An optical glass having a high light transmittance, a high refractive index and excellent production stability, which contains at least one of CaO and SrO together with SiO, BO, LaO, NbO, TiOand BaO, having a composition that substantially contains, by weight %, 1 to 18% of SiO, 3 to 24% of BO, provided that the ratio of content of BOto the content of SiO(BO/SiO) is over 1, 10 to 50% of LaO, 1 to 30% of NbO, 1 to 30% of TiO, over 6% but not more than 25% of BaO, less than 7% of CaO, 6% or less of SrO, 0 to 13% of MgO, provided that the total content of BaO, CaO, SrO and MgO is 40% or less, 0 to 15% of ZnO, 0 to 15% of ZrO, 0 to 10% of AlO, 0 to 20% of GdO, 0% or more but less than 2% of YO, 0 to 5% of YbO, 0 to 18% of TaO, 0 to 20% of BiO, 0 to 10% of GeO, 0% or more but less than 2% of SbO, and 0% or more but less than 2% of SnO, and having a refractive index (n) of over 1.8, Abbe's number (&#x3bd;) of 28 to 40 and a density of 4.2 g/cmor more.

Optical glass, glass gob for press-molding, optical part, process for producing glass shaped material and process for producing optical part

An optical glass whose refractive index is high and whose coloring is decreased comprising, by weight %, 2 to 45% of BO, 0 to 30% of SiOprovided that the content of BO&#x3e;the content of SiO, 10 to 50% of LaO, 0 to 30% of TiO, 0 to 15% of ZnO, 0 to 15% of ZrO, 0 to 35% of NbO, 0 to 35% of BaO, 0 to 5% of SrO, 0% or more but less than 8% of CaO, 0% or more but less than 13% of MgO, provided that the total content of BaO, SrO, CaO and MgO is 0 to 40%, 0 to 20% of GdO, 0 to 15% of YO, 0 to 18% of TaO, 0% or more but less than 0.5% of WO, 0% or more but less than 1.5% of a total of NaO, KO and LiO, 0 to 10% of GeO, 0 to 20% of BiO, 0 to 10% of YbO, 0 to 10% of AlO, 0% or more but less than 2% of SbOand 0 to 1% of SnO.

An optical glass that substantially does not contain any Ta O and has high-refractivity low-dispersion optical properties and various optical parts made of such optical glass are provided stably at a low cost, and an optical part made thereof is provided, the optical glass having a glass composition comprising, by weight %, 0 to 7% of SiO , 18 to 30% of B O , provided that the total content of SiO and B O is 23 to 35%, 2 to 10% of ZnO, 30 to 50% of La O , 0 to 20% of Gd O , 0 to 20% of Y O , provided that the total content of La O , Gd O and Y O is 45 to 60%, 3 to 8% of ZrO and 3 to 12% of Nb O , the total content of these components being at least 95% by weight, the optical glass having a refractive index &lsqb;nd&rsqb; and an Abbe's number &lsqb;&ngr;d&rsqb; which satisfy specified relational expressions.

Growing community of inventors

Utsunomiya, Japan

Michio Endo