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

Patent metadata

Field	Value
Publication number	US-11254602-B2
Application number	US-201816167227-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Oct 25, 2017
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

An optical glass includes La3+, Zn2+, Nb5+, and Ti4+ as a cation configuring glass. La3+, Zn2+, Nb5+, and Ti4+ which satisfy 10 cat %≤La3+≤20 cat %, 10 cat %≤Zn2+≤60 cat %, 20 cat %≤Nb5+≤60 cat %, and 0 cat %≤Ti4+≤40 cat % expressed by cation %.

First claim

What is claimed is:

1. An optical glass comprising:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,

wherein B 2 O 3 is not contained in the optical glass.

2. The optical glass according to claim 1 , satisfying:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤6.0 cat %;
30 cat %≤Nb 5+ ≤60 cat %; and
Ti 4+ =0 cat %.

3. The optical glass according to claim 1 , satisfying
60 cat % (Total amount of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Lu 3+ , Zn 2+ , and Nb 5± )≤100 cat %.

4. The optical glass according to claim 1 , wherein
a refractive index at a d-line is 2.20 or more and 2.28 or less, and
an Abbe number is 19 or more and 22 or less.

5. The optical glass according to claim 1 , wherein
a glass transition point (Tg) is 705° C. or less.

6. An optical element comprising:
an optical glass comprising:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,

wherein B 2 O 3 is not contained in the optical glass.

7. The optical element according to claim 6 , wherein
the optical element is any one of a lens, a prism or a mirror.

8. An optical instrument comprising:
an optical element, wherein
the optical element is the optical element according to claim 6 .

9. The optical instrument according to claim 8 , wherein
the optical instrument is a camera, and the optical element is a lens.

10. A method for manufacturing an optical glass using a containerless solidification method, the method comprising:
levitating a glass material with a levitation gas, wherein the glass material comprises:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,

wherein B 2 O 3 is not contained in the glass;

heating and melting the levitated glass material to obtain a melt; and
cooling and solidifying the melt in a state where the melt is levitated.

11. The method for manufacturing an optical glass according to claim 10 , wherein the optical glass material satisfies:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
30 cat %≤Nb 5+ ≤60 cat %; and
Ti 4+ =0 cat %.

12. The method for manufacturing an optical glass according to claim 10 , wherein
the optical glass material satisfies
60 cat %≤(Total amount of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Lu 3+ , Zn 2+ , and Nb 5+ )≤100 cat %.

Assignees

• Canon Kk

Inventors

• Endo Michio

Classifications

• C03C3/155 Primary

  containing zirconium, titanium, tantalum or niobium · CPC title

• C03B19/102

  by blowing a gas onto a stream of molten glass or onto particulate materials, e.g. pulverising · CPC title

• C03B2215/12

  Ceramics or cermets, e.g. cemented WC, Al2O3 or TiC · CPC title

• C03B11/122

  Heating · CPC title

• C03B2215/48

  Convex-concave · CPC title