US 12,351,502 B2
Optical glass and optical element
Koichi Tsuchiya, Saitama (JP); and Hideaki Takaku, Saitama (JP)
Assigned to Sumita Optical Glass, Inc., Saitama (JP)
Appl. No. 16/493,528
Filed by Sumita Optical Glass, Inc., Saitama (JP)
PCT Filed Apr. 18, 2017, PCT No. PCT/JP2017/015578
§ 371(c)(1), (2) Date Sep. 12, 2019,
PCT Pub. No. WO2018/185946, PCT Pub. Date Oct. 11, 2018.
Claims priority of application No. 2017-075549 (JP), filed on Apr. 5, 2017.
Prior Publication US 2020/0131072 A1, Apr. 30, 2020
Int. Cl. C03B 37/012 (2006.01); C03C 3/066 (2006.01); C03C 3/068 (2006.01); C03C 3/078 (2006.01); C03C 3/089 (2006.01); C03C 3/095 (2006.01); C03C 13/04 (2006.01)
CPC C03B 37/012 (2013.01) [C03C 3/066 (2013.01); C03C 3/068 (2013.01); C03C 3/078 (2013.01); C03C 3/089 (2013.01); C03C 3/095 (2013.01); C03C 13/04 (2013.01)] 17 Claims
 
1. An optical glass having a composition including only, in % by mass:
30% or more and 47% or less of SiO2;
0% or more and 10% or less of B2O3;
3% or more and 12% or less of Na2O;
0% or more and 5% or less of Li2O;
0% or more and 3.8% or less of CaO;
28% or more and 43% or less of BaO;
3% or more and 16% or less of ZnO;
0.5% or more and 8% or less of ZrO2; and
0% or more and 15% or less of La2O3,
wherein the composition optionally includes Sb2O3,
where the proportions of SiO2, B2O3, Na2O, Li2O, CaO, BaO, ZnO, ZrO2, and La2O3, are relative to the sum of the contents of the components except for Sb2O3, if included, constituting the composition, and
the optical glass has a proportion of a content of BaO in a sum of contents of CaO and BaO of 91.5% by mass or more.