Optical glass, optical element blank, and optical element
An optical glass which has a refractive index nd of 1.80 to 2.00 and an Abbe number νd of 17 to 22, contains 25 to 40 mass % of P 2 O 5 , 15 to 40 mass % of Nb 2 O 5 , 10 to 35 mass % of TiO 2 , 3 to 12 mass % of B 2 O 3 , 0 to 15 mass % of BaO, greater than 0 mass % and 10 mass % or less of Li 2 O, greater than 0 mass % and 15 mass % or less of a total of Li 2 O, Na 2 O, K 2 O, and Cs 2 O [Li 2 O+Na 2 O+K 2 O+Cs 2 O], has a mass ratio [TiO 2 /(Nb 2 O 5 +TiO 2 +WO 3 +Bi 2 O 3 +Ta 2 O 5 )] of TiO 2 to the total of Nb 2 O 5 , TiO 2 , WO 3 , Bi 2 O 3 , and Ta 2 O 5 of 0.33 to 0.60, and does not substantially contain F.
1 . Optical glass,
wherein a refractive index nd is 1.80 to 2.00,
an Abbe's number νd is 17 to 22,
a content of P 2 O 5 is 25 to 40% by mass,
a content of Nb 2 O 5 is 15 to 40% by mass,
a content of TiO 2 is 10 to 35% by mass,
a content of B 2 O 3 is 3 to 12% by mass,
a content of BaO is 0 to 5% by mass,
a content of Li 2 O is greater than 0% by mass and 10% by mass or less,
a total content [Li 2 O+Na 2 O+K 2 O+Cs 2 O] of Li 2 O, Na 2 O, K 2 O, and Cs 2 O is greater than 0% by mass and 15% by mass or less,
a mass ratio [TiO 2 /(Nb 2 O 5 +TiO 2 +WO 3 +Bi 2 O 3 +Ta 2 O 5 )] of the content of TiO 2 to a total content of Nb 2 O 5 , TiO 2 , WO 3 , Bi 2 O 3 , and Ta 2 O 5 is 0.37 to 0.60, and
F is not substantially contained.
2 . An optical element blank, comprising the optical glass according to claim 1 .
3 . An optical element, comprising the optical glass according to claim 1 .
4 . Alight guide plate, comprising the optical glass according to claim 1 .
5 . An image display device, comprising:
an image display element; and
a light guide plate guiding light exiting from the image display element,
wherein the light guide plate comprises the optical glass according to claim 1 .
6 . Optical glass according to claim 1 ,
wherein a content of SiO 2 is 3% by mass or less,
a content of Al 2 O 3 is 3% by mass or less,
a total content [P 2 O 5 +B 2 O 3 +SiO 2 +Al 2 O 3 ] of P 2 O 5 , B 2 O 3 , SiO 2 , and Al 2 O 3 is 28 to 45% by mass,
a content of WO 3 is 5% by mass or less,
a content of Bi 2 O 3 is 5% by mass or less,
a total content [TiO 2 +Nb 2 O 5 +WO 3 +Bi 2 O 3 ] of TiO 2 , Nb 2 O 5 , WO 3 , and Bi 2 O 3 is 40 to 65% by mass,
a mass ratio [(P 2 O 5 +B 2 O 3 +SiO 2 +Al 2 O 3 )/(TiO 2 +Nb 2 O 5 +WO 3 +Bi 2 O 3 )] of the total content of P 2 O 5 , B 2 O 3 , SiO 2 , and Al 2 O 3 to the total content of TiO 2 , Nb 2 O 5 , WO 3 , and Bi 2 O 3 is 0.50 to 0.85,
a content of Na 2 O is 5.0% by mass or less,
a content of K 2 O is 12% by mass or less,
a content of Cs 2 O is 2% by mass or less,
a content of MgO is 10% by mass or less,
a content of CaO is 5% by mass or less,
a content of SrO is 5% by mass or less,
a total content [MgO+CaO+SrO+BaO] of MgO, CaO, SrO, and BaO is 10% by mass or less,
a content of ZnO is 5% by mass or less,
a content of ZrO 2 is 5% by mass or less,
a content of Ta 2 O 5 is 5% by mass or less,
a content of Sc 2 O 3 is 2% by mass or less,
a content of HfO 2 is 2% by mass or less,
a content of Lu 2 O 3 is 2% by mass or less,
a content of GeO 2 is 2% by mass or less,
a content of La 2 O 3 is 2% by mass or less,
a content of Gd 2 O 3 is 2% by mass or less,
a content of Y 2 O 3 is 2% by mass or less,
a content of Yb 2 O 3 is 2% by mass or less,
a total content of P 2 O 5 , Nb 2 O 5 , TiO 2 , B 2 O 3 , Li 2 O, BaO, SiO 2 , Al 2 O 3 , WO 3 , Bi 2 O 3 , Na 2 O, K 2 O, Cs 2 O, MgO, CaO, SrO, ZnO, ZrO 2 , Ta 2 O 5 , Sc 2 O 3 , HfO 2 , Lu 2 O 3 , GeO 2 , La 2 O 3 , Gd 2 O 3 , Y 2 O 3 , and Yb 2 O 3 is 95% by mass or more, and a content of TeO 2 is 2% by mass or less.
7 . Phosphate optical glass containing Nb 2 O 5 and TiO 2 ,
wherein a mass ratio [(P 2 O 5 +B 2 O 3 +SiO 2 +Al 2 O 3 )/(TiO 2 +Nb 2 O 5 +WO 3 +Bi 2 O 3 )] of the total content of P 2 O 5 , B 2 O 3 , SiO 2 , and Al 2 O 3 to the total content of TiO 2 , Nb 2 O 5 , WO 3 , and Bi 2 O 3 is 0.50 to 0.85,
an Abbe's number νd is 17 or more, and
a refractive index nd and a specific gravity d satisfy Expression (1) described below:
nd≥ 0.5× d+ 0.225 (1).
8 . An optical element blank, comprising the optical glass according to claim 7 .
9 . An optical element, comprising the optical glass according to claim 7 .
10 . Alight guide plate, comprising the optical glass according to claim 7 .
11 . An image display device, comprising:
an image display element; and
a light guide plate guiding light exiting from the image display element,
wherein the light guide plate comprises the optical glass according to claim 7 .
12 . Phosphate optical glass according to claim 7 , wherein a content of P 2 O 5 is 25 to 40% by mass.
13 . Phosphate optical glass according to claim 7 , wherein a content of Nb 2 O 5 is 15 to 40% by mass.
14 . Phosphate optical glass according to claim 7 , wherein a content of TiO 2 is 10 to 35% by mass.
15 . Phosphate optical glass according to claim 7 , wherein a content of B 2 O 3 is 3 to 12% by mass.
16 . Phosphate optical glass according to claim 7 , wherein a content of BaO is 0 to 15% by mass, and a content of Li 2 O is greater than 0% by mass and 10% by mass or less.
17 . Phosphate optical glass according to claim 7 , wherein a total content [Li 2 O+Na 2 O+K 2 O+Cs 2 O] of Li 2 O, Na 2 O, K 2 O, and Cs 2 O is greater than 0% by mass and 15% by mass or less.
18 . Phosphate optical glass according to claim 7 , wherein a mass ratio [TiO 2 /(Nb 2 O 5 +TiO 2 +WO 3 +Bi 2 O 3 +Ta 2 O 5 )] of the content of TiO 2 to a total content of Nb 2 O 5 , TiO 2 , WO 3 , Bi 2 O 3 , and Ta 2 O 5 is 0.33 to 0.60.
19 . Phosphate optical glass according to claim 7 , wherein F is not substantially contained.
20 . Phosphate optical glass according to claim 7 ,
wherein a content of SiO 2 is 3% by mass or less,
a content of Al 2 O 3 is 3% by mass or less,
a total content [P 2 O 5 +B 2 O 3 +SiO 2 +Al 2 O 3 ] of P 2 O 5 , B 2 O 3 , SiO 2 , and Al 2 O 3 is 28 to 45% by mass,
a content of WO 3 is 5% by mass or less,
a content of Bi 2 O 3 is 5% by mass or less,
a total content [TiO 2 +Nb 2 O 5 +WO 3 +Bi 2 O 3 ] of TiO 2 , Nb 2 O 5 , WO 3 , and Bi 2 O 3 is 40 to 65% by mass,
a content of Na 2 O is 5.0% by mass or less,
a content of K 2 O is 12% by mass or less,
a content of Cs 2 O is 2% by mass or less,
a content of MgO is 10% by mass or less,
a content of CaO is 5% by mass or less,
a content of SrO is 5% by mass or less,
a total content [MgO+CaO+SrO+BaO] of MgO, CaO, SrO, and BaO is 10% by mass or less,
a content of ZnO is 5% by mass or less,
a content of ZrO 2 is 5% by mass or less,
a content of Ta 2 O 5 is 5% by mass or less,
a content of Sc 2 O 3 is 2% by mass or less,
a content of HfO 2 is 2% by mass or less,
a content of Lu 2 O 3 is 2% by mass or less,
a content of GeO 2 is 2% by mass or less,
a content of La 2 O 3 is 2% by mass or less,
a content of Gd 2 O 3 is 2% by mass or less,
a content of Y 2 O 3 is 2% by mass or less,
a content of Yb 2 O 3 is 2% by mass or less,
a total content of P 2 O 5 , Nb 2 O 5 , TiO 2 , B 2 O 3 , Li 2 O, BaO, SiO 2 , Al 2 O 3 , WO 3 , Bi 2 O 3 , Na 2 O, K 2 O, Cs 2 O, MgO, CaO, SrO, ZnO, ZrO 2 , Ta 2 O 5 , Sc 2 O 3 , HfO 2 , Lu 2 O 3 , GeO 2 , La 2 O 3 , Gd 2 O 3 , Y 2 O 3 , and Yb 2 O 3 is 95% by mass or more, and a content of TeO 2 is 2% by mass or less.