Highly refractive and highly transparent optical glass
AssigneeSchott AG
InventorsSimone Ritter, Ute Woelfel, Stefanie Hansen
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Abstract
The optical glass has a refractive index nd of 1.945≦nd≦1.97, an Abbe number νd of 33≦νd≦36, and a composition with the following components in amounts expressed in % of their cations, with respect to the total number of cations in the composition: B3+, 35-46; La3+, 25-35; Ta5+, 6-14; W6+, 6-13; Zr4+, 1-7; Gd3+, 0-5; Nb5+, 0-4; Y+3, 0-4; Ba2+, 0-2; Σ alkaline earth metal cations, 0-2, Σ La3++Ta3++W6++Zr4++Gd3++Nb5++Y3+≧50; and at least one fining agent, 0-0.3. Also a ratio of B3+ to La+3 is 1.1 to 1.6 and a ratio of B3+ to Σ Si+4+B3+ is ≧0.5. The glass is free of lead, arsenic, Ti4+, Th4+, Zn2+, F−, and Hf+4.
Claims8
A lead-free and arsenic-free optical glass having a refractive index nd of 1.945≦nd≦1.97, an Abbe number νd of 33≦νd≦36, and an internal transmittance of >80% at 410 nm and at a thickness of 10 mm, wherein said optical glass has a composition comprising respective components in the following amounts expressed in % of corresponding cations of said respective components in said composition, with reference to a sum of all cations in the composition:
- B3+
- 35-46
- La3+
- 25-35
- Ta5+
- 6-14
- W6+
- 6-13
- Zr4+
- 1-7
- Gd3+
- 0-5
- Nb5+
- 0-4
- Y3+
- 0-4
- Ba2+
- 0-2
- Σalkaline earth metal cations
- 0-2
- ΣLa3+ + Ta5+ + W6+ + Zr4+ + Gd3+ + Nb5+ + Y3+
- ≧50
- cations of at least one fining agent
- 0-0.3,
- wherein a ratio of B3+ to La3+ is 1.1 to 1.6, a ratio of B3+ to Σ Si4++B3+ is greater than 0.5, and the glass is free of Ti4+, Th4+, Zn2+, F− and Hf4+, and wherein the glass contains less than 6 ppm of platinum.
A lead-free and arsenic-free optical glass having a refractive index nd of 1.945≦nd≦1.97, an Abbe number νd of 33≦νd≦36, and an internal transmittance of >80% at 410 nm and at a thickness of 10 mm, wherein said optical glass has a composition comprising respective components are contained in the following amounts expressed in % of the corresponding cations in said composition, with reference to the sum of the cations in the composition:
- B3+
- 37-44
- La3+
- 27-33
- Ta5+
- 8-12
- W6+
- 8-11
- Zr4+
- 2-5
- Gd3+
- 0.5-4
- Nb5+
- 0.5-2
- Y3+
- 0-2.5
- Ba2+
- 0-1
- Σalkaline earth metal cations
- 0-2
- ΣLa3+ + Ta5+ + W6+ + Zr4+ + Gd3+ + Nb5+ + Y3+
- ≧53
- cations of at least one fining agent
- 0-0.1,
- wherein a ratio of B3+ to La3+ is 1.2 to 1.5, a ratio of B3+ to Σ Si4++B3+ is greater than 0.8, and the glass is free of Ti4+, Th4+, Zn2+, F− and Hf4+, and wherein the glass contains less than 6 ppm of platinum.
Dependencies are inferred from the claim text.