Optical glass

• US 10,287,205 B2
• Filed: 04/06/2016
• Issued: 05/14/2019
• Est. Priority Date: 04/10/2015
• Status: Active Grant

• Current Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Original Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Inventors: Sun, Wei
• Primary Examiner(s): Bolden, Elizabeth A.
• Application Number:
  US15/546,244
• Publication Number:
  US 20180016182A1
• Time in Patent Office: 1,133 Days
• CPC Class Codes: C03C 2201/3411 Yttrium
• CPC Class Codes: C03C 2201/3417 Lanthanum
• CPC Class Codes: C03C 2201/3452 Gadolinium
• CPC Class Codes: C03C 2201/3488 Ytterbium
• CPC Class Codes: C03C 3/068 containing rare earths
• CPC Class Codes: G02B 1/00 Optical elements characterised by the material of which they are made; Optical coatings for optical elements
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures
• CPC Class Codes: G02B 27/0062 by controlling the dispersion of a lens material, e.g. adapting the relative partial dispersion
• CPC Class Codes: G02B 3/0087 with index gradient

Abstract

An optical glass with high refractive index and low dispersion, having refractive index nd of 1.78-1.95, Abbe number νd of 32-50, and contains no GeO₂, so it is not easily devitrified. An optical glass, represented by cation %, including: 1-20% of Si⁴⁺; 25-60% of B³⁺; 10-40% of La³⁺; 0-15% of Y³⁺; 0-20% of Nb⁵⁺; 0-15% of Ti⁴⁺; 0-10% of Ta⁵⁺; 0-5% of W⁶⁺; 0-15% of Zr⁴⁺; 0-10% of Zn²⁺; 0-10% of Bi³⁺. An optical glass with excellent transmittance, an optical glass preform and an optical element formed by the above optical glass. The optical element made by the above optical glass and the above glass preform or optical element blank, such as lens, can be used for optical systems.

Claims

1. An optical glass, represented by cation %, comprising:

30-less than 45% of B³⁺;

the total amount of Si⁴⁺ and B³⁺ being 40-55%;

5-13% of Si⁴⁺;

20-35% of La³⁺;

0-15% of Y³⁺;

1-8% of Gd³⁺;

0-5% of Yb³⁺;

the total amount of La³⁺, Y³⁺, Gd³⁺ and Yb³⁺ being 30-50%;

(Si⁴⁺+B³⁺)/(La³⁺+Y³⁺+Gd³⁺+Yb³⁺) is greater than 1 but less than 1.8;

0.5-10% of Nb⁵⁺;

3-8% of Ti⁴⁺;

0-10% of Ta⁵⁺;

0-5% of W⁶⁺;

the total amount of Nb⁵⁺, Ti⁴⁺, Ta⁵⁺ and W⁶⁺ being 3.5-15%;

(Nb⁵⁺+Ti⁴⁺)/(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺) being 0.7-1;

(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺)/(Si⁴⁺+B³⁺) being 0.06-0.35;

(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺)/(La³⁺+Y³⁺+Gd³⁺+Yb³⁺) being 0.07-0.4;

0-10% of Zr⁴⁺;

0-10% of Zn²⁺;

0-10% of Bi³⁺.

2. The optical glass according to claim 1, also optionally comprising:

Li⁺, Na⁺ and K⁺ in a total amount of less than 10%;

and Ba²⁺, Mg²⁺, Ca²⁺ and Sr²⁺ in a total amount of less than 10%.

3. The optical glass according to claim 2, wherein:

the total amount of Li⁺, Na⁺ and K⁺ being less than 5%;

and the total amount of Ba²⁺, Mg²⁺, Ca²⁺ and Sr²⁺ being less than 5%.

4. The optical glass according to claim 1, wherein 2.5-8% of Gd³⁺;

and 3-7% of Ti⁴⁺.

5. The optical glass according to claim 1, wherein the composition is free of Ta⁵⁺.

6. The optical glass according to claim 1, wherein the refractive index nd of glass is 1.85-1.95, the Abbe number ν

d is 32-40, and the corresponding wavelength is below 420 nm when the transmittance of glass reaches 70%, the glass density is below 5 g/cm³, and the upper limit of devitrification temperature of glass is below 1250°

C.

7. A glass preform, which is made of the optical glass according to claim 1.

8. An optical element, which is made of the optical glass according to claim 1.

9. An optical glass, represented by cation %, comprising:

5-13% of Si⁴⁺;

45-55% of B³⁺;

the total amount of Si⁴⁺ and B³⁺ being 50-65%;

15-35% of La³⁺;

0-10% of Y³⁺;

0-8% of Gd³⁺,

0-5% of Yb³⁺;

the total amount of La³⁺, Y³⁺, Gd³⁺ and Yb³⁺ being 25-45%;

(Si⁴⁺+B³⁺)/(La³⁺+Y³⁺+Gd³⁺+Yb³⁺) is 1.7-2.3;

0.5-20% of Nb⁵⁺;

0-5% of Ti⁴⁺;

0-7% of Ta⁵⁺;

0-5% of W⁶⁺;

the total amount of Nb⁵⁺, Ti⁴⁺, Ta⁵⁺ and W⁶⁺ being 0.5-20%;

(Nb⁵⁺+Ti⁴⁺)/(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺) being 0.7-1;

(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺)/(Si⁴⁺+B³⁺) being 0.01-0.35;

(Nb⁵⁺+Ti⁴⁺+Ta⁵⁺+W⁶⁺)/(La³⁺+Y³⁺+Gd³⁺+Yb³⁺) being 0.04-0.4;

0-10% of Zr⁴⁺;

0.5-5% of Zn²⁺;

0-6% of Bi³⁺.

10. The optical glass according to claim 9, also optionally comprising:

Li⁺, Na⁺ and K⁺ in a total amount of less than 10%;

and Ba²⁺, Mg²⁺, Ca²⁺ and Sr²⁺ in a total amount of less than 10%.

11. The optical glass according to claim 10, wherein:

the total amount of Li⁺, Na⁺ and K⁺ being less than 5%;

and the total amount of Ba²⁺, Mg²⁺, Ca²⁺ and Sr²⁺ being less than 5%.

12. The optical glass according to claim 9, wherein:

1.1-3% of Zn²⁺;

0-less than 2.5% of Gd³⁺;

0-less than 3% of Ti⁴⁺.

13. The optical glass according to claim 9, wherein the composition is free of Ta⁵⁺.

14. The optical glass according to claim 9, wherein the refractive index nd is 1.78-1.85, the Abbe number ν

d is 40-50, the corresponding wavelength is below 420 nm when the transmittance of glass reaches 80%, the density is below 5 g/cm³, and the upper limit of devitrification temperature is below 1250°

C.

15. A glass preform, which is made of the optical glass according to claim 9.

16. An optical element, which is made of the optical glass according to claim 9.