OPTICAL GLASS

• US 20180230038A1
• Filed: 08/10/2016
• Published: 08/16/2018
• Est. Priority Date: 08/14/2015
• Status: Active Application

• Current Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Original Assignee: CDGM Glass Company Limited (Konica Minolta Inc.)
• Inventors: SUN, Wei
• Granted Patent: US 10,259,738 B2
• Time in Patent Office: Days
• CPC Class Codes: C03C 3/068 containing rare earths
• CPC Class Codes: C03C 3/155 containing zirconium, titanium, tantalum or niobium

Abstract

A high refraction low dispersion optical glass having a refractive index of 1.86-1.92 and an Abbe number of 36-42. The components of the optical glass comprise, by weight percentage: B₂O₃: 1-30%; SiO₂: 0-20%; La₂O₃: 25-55%; Gd₂O₃: 5-40%; Y₂O₃: 0-25%; Yb₂O₃: 0-10%; Ta₂O₅: 0-10%; Nb₂O₅: 1-30%; TiO₂: 0-10%; ZrO₂: 0.5-20%; WO₃: 0-10%; ZnO: 0-15%; Al₂O₃: 0-10%; GeO₂: 0-10%; Bi₂O₃: 0-10%. The optical glass does not contain PbO or F. A high refraction low dispersion optical glass having excellent light transmittance may be obtained by introducing suitable amounts of rare earth oxides having a high refraction low dispersion effect and optimising the proportions of said components.

Claims

1. An optical glass, comprising by weight percentage:

B₂O₃;

1-30%;

SiO₂;

0-20%, wherein SiO₂≤

B₂O₃;

La₂O₃;

25-55%;

Gd₂O₃;

5-40%;

Y₂O₃;

0-25%;

Yb₂O₃;

0-10%;

Ta₂O₅;

0-10%;

Nb₂O₅;

1-30%;

TiO₂;

0-10%;

ZrO₂;

0.5-20%;

Nb₂O₅ is greater than or equal to ZrO₂;

Nb₂O₅/(Nb₂O₅+TiO₂+ZrO₂) is in the range of 0.4-0.8;

WO₃;

0-10%;

ZnO;

0-15%;

Al₂O₃;

0-10%;

GeO₂;

0-10%;

Bi₂O₃;

0-10%;

PbO and F are excluded;

the glass refractive index is 1.86-1.92 and the Abbe number is 36-42.

2. The optical glass according to claim 1, further containing:

Sb₂O₃;

0-1% and/or SnO₂;

0-1% and/or CeO₂;

0-1% and R₂O;

0-10%, wherein R₂O is one or more kinds of Li₂O, Na₂O or K₂O; and

/or RO;

0-10%, wherein RO is one or more kinds of BaO, SrO, MgO or CaO.

3. The optical glass according to claim 1, further containing B₂O₃:

5-25% and/or SiO₂;

0.1-15% and/or La₂O₃;

30-52% and/or Gd₂O₃;

5-35% and/or Y₂O₃;

1-20% and/or Ta₂O₅;

0-5% and/or Nb₂O₅;

2-25% and/or TiO₂;

0.1-5% and/or ZrO₂;

1-15% and/or WO₃;

0-5% and/or ZnO;

0-10% and/or R₂O;

0-5% and/or RO;

0-5% and/or Al₂O₃;

0-5% and/or GeO₂;

0-5% and/or Bi₂O₃;

0-5% and/or Sb₂O₃;

0-0.5% and/or SnO₂;

0-0.5% and/or CeO₂;

0-0.5%.

4. The optical glass according to claim 1, wherein SiO₂/(SiO₂+B₂O₃) is in the range of below 0.5;

and/or

Y₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃+Yb₂O₃) is in the range of below 0.2; and

/or

Y₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) is in the range of 0.01-0.15; and

/or Nb₂O₅/(Nb₂O₅+TiO₂+ZrO₂) is in the range of 0.45-0.7; and

/or (Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) is in the range of less than 1; and

/or (ZnO+Y₂O₃)/La₂O₃ is in the range of below 0.5.

5. The optical glass according to claim 1, wherein SiO₂/(SiO₂+B₂O₃) is in the range of 0.1-0.45;

and/or Y₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) is in the range of below 0.05-0.12; and

/or Nb₂O₅/(Nb₂O₅+TiO₂+ZrO₂) is in the range of 0.48-0.6; and

/or (Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) is in the range of 0.1-0.9; and

/or

(ZnO+Y₂O₃)/La₂O₃ is in the range of below 0.05-0.3.

6. The optical glass according to claim 1, wherein SiO₂/(SiO₂+B₂O₃) is in the range of 0.25-0.4;

and/or

(Nb₂O₅+Ta₂O₅+ZrO₂)/(SiO₂+B₂O₃) is in the range of 0.5-0.8; and

/or (ZnO+Y₂O₃)/La₂O₃ is in the range of below 0.08-0.15.

7. The optical glass according to claim 1, wherein the glass refractive index ranges from 1.87 to 1.91, and the Abbe number ranges from 37 to 41.

8. The optical glass according to claim 1, wherein the glass refractive index ranges from 1.88 to 1.90, and the Abbe number ranges from 38 to 40.

9. A glass preform, made of the optical glass according to claim 1.

10. An optical element, made of the optical glass according to claim 1.