Optical glass, precision press molding preform, and optical element and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9255028-B2
Application number	US-201314397326-A
Country	US
Kind code	B2
Filing date	Apr 24, 2013
Priority date	Apr 26, 2012
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

The optical glass is described that may be an oxide glass including, denoted as cation %, a total of 5 to 60% of B 3+ and Si 4+ (with 5 to 50% of B 3+ ), a total of equal to or higher than 5% of Zn 2+ and Mg 2+ , a total of 10 to 50% of La 3+ , Gd 3+ , Y 3+ , and Yb 3+ , and a total of 6 to 45% of Ti 4+ , Nb 5+ , Ta 5+ , W 6+ , and Bi 3+ (a total content of Ti 4+ and Ta 5+ being higher than 0% and a content of W 6+ being higher than 5%).

First claim

The invention claimed is:

1. Optical glass, which is oxide glass comprising, denoted as cation %,
a total of 5 to 60% of B 3+ and with 5 to 50% of B 3+ ,
a total of equal to or higher than 5% of Zn 2+ and Mg 2+ ,
a total of 10 to 50% of La 3+ , Gd 3+ , Y 3+ , and Yb 3+ , and
a total of 6 to 45% of Ti 4+ , Nb 5+ , Ta 5+ , W 6+ , and Bi 3+ , with a total content of Ti 4+ and Ta 5+ being higher than 0% and a content of W 6+ being higher than 5%;
wherein a cation ratio of a content of Si 4+ to a content of B 3+ , Si 4+ /B 3+ , is equal to or lower than 0.70;
a cation ratio of a content of Ta 5+ to a total content of Ti 4+ and Ta 5+ , Ta 5+ /(Ti 4+ +Ta 5+ ), is equal to or higher than 0.23;
a cation ratio of a content of W 6+ to a total content of Nb 5+ and W 6+ , W 6+ /(Nb 5+ +W 6+ ), is equal to or higher than 0.30;
a cation ratio of a total content of Ti 4+ , Nb 5+ , Ta 5+ , W 6+ , and B 3+ to a total content of B 3+ and Si 4+ , (Ti 4+ +Nb 5+ +Ta 5+ +W 6+ +B 3+ )/(B 3+ +Si 4+ ), is higher than 0.37 but equal to or lower than 3.00;
a cation ratio of a total content of Zn 2+ , Mg 2+ , and Li + to a total content of La 3+ , Gd 3+ , Y 3+ , and Yb 3+ , (Zn 2+ +Mg 2+ +Li + )/(La 3+ +Gd 3+ +Y 3+ +Yb 3+ ), is equal to or higher than 0.40; and
which has a refractive index nd ranging from 1.90 to 2.00 and an Abbé number νd satisfying the following equation (1):
25≦ν d <(3.91− nd )/0.06  (1).

2. The optical glass according to claim 1 , which has a glass transition temperature of equal to or lower than 650° C.

3. The optical glass according to claim 1 , wherein a content of Ge is less than 5.0 mass % as a content of GeO 2 in a glass composition based on oxides, and a cation ratio of a content of Te 4+ to a total content of Zn 2+ and Mg 2+ , Te 4+ /(Zn 2+ +Mg 2+ ), is lower than 1.

4. The optical glass according to claim 1 , which comprises equal to or higher than 8 cation % of Zn 2+ and Mg 2+ combined.

5. The optical glass according to claim 1 , wherein a content of Yb is lower than 2.0 mass % as a content of Yb 2 O 3 in a glass composition based on oxides.

6. A precision press molding preform, which is comprised of the optical glass according to claim 1 .

7. An optical element, which is comprised of the optical glass according to claim 1 .

8. A method of manufacturing an optical element, which comprises heating and precision press molding with a pressing mold the precision press molding preform according to claim 6 to obtain an optical element.

9. The method of manufacturing an optical element according to claim 8 , which comprises heating the precision press molding preform together with a pressing mold after introducing the precision press molding preform into the pressing mold.

10. The method of manufacturing an optical element according to claim 8 , which comprises heating the precision press molding preform and then introducing into a pressing mold to conducting the precision press molding.

Assignees

• Negishi Tomoaki
• Fujiwara Yasuhiro
• Hoya Corp

Inventors

• Negishi Tomoaki
• Fujiwara Yasuhiro

Classifications

• C03B11/122

  Heating · CPC title

• C03B2215/63

  Pressing between porous dies supplied with gas, i.e. contactless pressing · CPC title

• C03B11/16

  Gearing or controlling mechanisms specially adapted for glass presses · CPC title

• C03C3/253 Primary

  containing germanium · CPC title

• C03B40/04

  using gas · CPC title