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

Patent metadata

Field	Value
Publication number	US-11840480-B2
Application number	US-202017088216-A
Country	US
Kind code	B2
Filing date	Nov 3, 2020
Priority date	May 11, 2018
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

Provided is an optical glass containing glass-forming cations, the optical glass satisfying, expressed in cation percent, 10 cat %≤B3+≤50 cat %, 15 cat %≤La3+≤35 cat %, 20 cat %≤Nb5+≤50 cat %, and 15 cat %≤Ti4+≤25 cat %.

First claim

The invention claimed is:

1. An optical glass, comprising:
glass-forming cations, the optical glass satisfying, expressed in cation percent:
10 cat %≤B 3+ ≤50 cat %,
15 cat %≤La 3+ ≤35 cat %,
20 cat %≤Nb 5+ ≤50 cat %, and
15 cat %≤Ti 4+ ≤25 cat %.

2. The optical glass according to claim 1 ,
wherein the optical glass satisfies 20 cat %≤B 3+ ≤50 cat %.

3. The optical glass according to claim 1 , wherein the optical glass satisfies:
0 cat %≤Al 3+ ≤5 cat %,
0 cat %≤Ga 3+ ≤5 cat %,
0 cat %≤Zn 2+ ≤10 cat %, and
0 cat %≤Ta 5+ ≤15 cat %.

4. The optical glass according to claim 1 ,
wherein the optical glass satisfies 0 cat %≤Pb 2+ ≤3 cat %.

5. The optical glass according to claim 1 ,
wherein the optical glass satisfies 85 cat % (total amount of B 3+ , La 3+ , Nb 5+ , and Ti 4+ )≤100 cat %.

6. The optical glass according to claim 1 , wherein the optical glass has a refractive index of 2.07 or more and 2.31 or less and an Abbe number of 18 or more and 25 or less for a d line.

7. The optical glass according to claim 1 , wherein the optical glass has a glass transition temperature (Tg) of 710° C. or lower.

8. An optical element, comprising the optical glass according to claim 1 , the optical glass being molded.

9. An optical device, comprising a housing and an optical system including multiple optical elements in the housing,
wherein each of the optical elements is the optical element according to claim 8 .

10. A method for producing an optical glass using a containerless solidification method, comprising the steps of levitating a glass material with a levitation gas, the glass material satisfying, expressed in cation percent:
10 cat %≤B 3+ ≤50 cat %,
15 cat %≤La 3+ ≤35 cat %,
20 cat %≤Nb 5+ ≤50 cat %, and
15 cat %≤Ti 4+ ≤25 cat %,
heating and melting the levitated glass material to form a melt, and cooling and solidifying the melt in a levitated state.

11. The method for producing an optical glass according to claim 10 ,
wherein the glass material satisfies
0 cat %≤Pb 2+ ≤3 cat %.

12. The method for producing an optical glass according to claim 10 , wherein the glass material satisfies:
0 cat %≤Al 3+ ≤5 cat %,
0 cat %≤Ga 3+ ≤5 cat %,
0 cat %≤Zn 2+ ≤10 cat %, and
0 cat %≤Ta 5+ ≤15 cat %.

13. The method for producing an optical glass according to claim 10 ,
wherein the glass material satisfies
85 cat %≤(total amount of B 3+ , La 3+ , Nb 5+ , and Ti 4+ )≤100 cat %.

14. A method for producing an optical element, comprising the steps of:
providing a lens preform of an optical glass containing glass-forming cations, the optical glass satisfying, expressed in cation percent:
10 cat %≤B 3+ ≤50 cat %,
15 cat %≤La 3+ ≤35 cat %,
20 cat %≤Nb 5+ ≤50 cat %, and
15 cat %≤Ti 4+ ≤25 cat %;
press-molding the heated lens preform with a mold member; and
releasing the molded lens preform from the mold member to form an optical element.

15. The method for producing an optical element according to claim 14 , wherein the mold member has a release film on a surface that comes into contact with the lens preform.

16. The method for producing an optical element according to claim 14 , wherein the release film is an amorphous carbon film.

Assignees

• Canon Kk

Inventors

• Endo Michio

Classifications

• C03C3/155 Primary

  containing zirconium, titanium, tantalum or niobium · CPC title

• C03B11/084

  material composition or material properties of press dies therefor · CPC title

• C03B2215/24

  Carbon, e.g. diamond, graphite, amorphous carbon · CPC title

• C03B11/086 Primary

  of coated dies (use of materials as release or lubricating compositions C03B40/02) · CPC title

• G02B1/00

  Optical elements characterised by the material of which they are made; Optical coatings for optical elements · CPC title