Patent US3887485A successfully refreshed from Google Patents.
US3887485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid optical filter having selective wavelength permeability
Assignee: Schott AG
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Filing: 1972-09-01
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Granted: 1975-06-03
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Expires: 1992-09-01
Abstract
Abstract The invention relates to a stray light filter comprising a solid light ray permeable material having a powder dispersed therein. The refractive index of the powder in the short-wave spectral range changes more greatly than that of the solid material in which the powder is embedded, so that in a specific wave length range the refractive indices of the solid material and the powder are equal. The embedding material is solid at the operational range of the filter and may, for instance, consist of at least one alkali halide and/or alkaline earth halide. The powder to be dispersed in the solid embedding material is selected from the group consisting, for instance, of oxide glass, an inorganic oxide and salts of oxygen-containing inorganic acids or mixtures of these materials.
Inventors
- 👤 Norbert Neuroth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:38
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/206
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
AN OPTICAL FILTER COMPRISING A COMPRESSED SOLID MASS OF LIGHT RAY PERMEABLE EMBEDDING POWDER; AND DISPERSED POWDER, SAID EMBEDDING POWDER HAVING A REFRACTIVE INDEX IN A SHORT-WAVE SPECTRAL RANGE SMALLER THAN THAT OF THE DISPERSED POWDER, SAID DISPEERSED POWDER POWDER HAVING A REFRACTION INDEX THAT CHANGES IN RELATION TO THE WAVE LENGTH OF THE LIGHT MORE GREATLY THAN THE REFRACTIVE INDEX OF THE EMBEDDING POWDER SO THAT IN A SPECIFIC WAVE LENGTH RANGE THE REFRACTIVE INDICES HOF EMBEDDING POWDER AND THE DISPERSED POWDER ARE EQUAL, SAID EMBEDDING POWDER BEING SOLID AND CAPABLE OF WITHSTANDING OPERTIONAL TEMPERATURES OF THE FILTER AS HIGH AS BETWEEN ABOUT 400* TO 600*C, IN WHICH SAID EMBEDDING POWDER IS SELECTED FROM THE GROUP CONSISTING OF LIF, CAF2, LAF2, NAF, AND BAF2 AND IN WHICH SAID DISPERSED POWDER CONSISTS OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF QUARTZ GLASS, NHCO3, BORO SILICATE GLASS, BORO SILICATE GLASS CONTAINING BAO AND LA2O3, QUARTZ CRYSTAL, PHOSPHATE FLUORIDE GLASS, GEO2 POWDER, BATIO3, MAGNESIUNM-ALUMINIM-SILICOBORATE GLASS, AND BARIUM BOROSILICATE GLASS.
Claim 2
Dependent Claim
167 words
AN OPTICAL FILTER COMPRISING A COMPRESSED SOLID MASS OF LIGHT RAY PERMEABLE EMBEDDING POWDER; AND DISPERSED POWDER, SAID EMBEDDING POWDER HAVING A REFRACTIVE INDEX IN A SHORT-WAVE SPECTRAL RANGE SMALLER THAN THAT OF THE DISPERSED POWDER, SAID DISPEERSED POWDER POWDER HAVING A REFRACTION INDEX THAT CHANGES IN RELATION TO THE WAVE LENGTH OF THE LIGHT MORE GREATLY THAN THE REFRACTIVE INDEX OF THE EMBEDDING POWDER SO THAT IN A SPECIFIC WAVE LENGTH RANGE THE REFRACTIVE INDICES HOF EMBEDDING POWDER AND THE DISPERSED POWDER ARE EQUAL, SAID EMBEDDING POWDER BEING SOLID AND CAPABLE OF WITHSTANDING OPERTIONAL TEMPERATURES OF THE FILTER AS HIGH AS BETWEEN ABOUT 400* TO 600*C, IN WHICH SAID EMBEDDING POWDER IS SELECTED FROM THE GROUP CONSISTING OF LIF, CAF2, LAF2, NAF, AND BAF2 AND IN WHICH SAID DISPERSED POWDER CONSISTS OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF QUARTZ GLASS, NHCO3, BORO SILICATE GLASS, BORO SILICATE GLASS CONTAINING BAO AND LA2O3, QUARTZ CRYSTAL, PHOSPHATE FLUORIDE GLASS, GEO2 POWDER, BATIO3, MAGNESIUNM-ALUMINIM-SILICOBORATE GLASS, AND BARIUM BOROSILICATE GLASS.
Claim 3
Dependent Claim
166 words
An optical filter comprising a compressed solid mass of light ray permeable embedding powder; and dispersed powder, said embedding powder having a refractive index in a short-wave spectral range smaller than that of the dispersed powder, said dispersed powder having a refraction index that changes in relation to the wave length of the light more greatly than the refractive index of the embedding powder so that in a specific wave length range the refractive indices of embedding powder and the dispersed powder are equal, said embedding powder being solid and capable of withstanding operational temperatures of the filter as high as between about 400* to 600*C, in which said embedding powder is selected from the group consisting of LiF, CaF2, LaF2, NaF, and BaF2 and in which said dispersed powder consists of material selected from the group consisting of quartz glass, NHCO3, boro silicate glass, boro silicate glass containing BaO and La2O3, quartz crystal, phosphate fluoride glass, GeO2 powder, baTio3, magNesium-aluminum-silicoborate glass, and barium borosilicate glass.
Claim 4
Dependent Claim
166 words
An optical filter comprising a compressed solid mass of light ray permeable embedding powder; and dispersed powder, said embedding powder having a refractive index in a short-wave spectral range smaller than that of the dispersed powder, said dispersed powder having a refraction index that changes in relation to the wave length of the light more greatly than the refractive index of the embedding powder so that in a specific wave length range the refractive indices of embedding powder and the dispersed powder are equal, said embedding powder being solid and capable of withstanding operational temperatures of the filter as high as between about 400* to 600*C, in which said embedding powder is selected from the group consisting of LiF, CaF2, LaF2, NaF, and BaF2 and in which said dispersed powder consists of material selected from the group consisting of quartz glass, NHCO3, boro silicate glass, boro silicate glass containing BaO and La2O3, quartz crystal, phosphate fluoride glass, GeO2 powder, baTio3, magNesium-aluminum-silicoborate glass, and barium borosilicate glass.
Claim 5
Dependent Claim
21 words
Optical filter according to claim 1, in which said embedding material consists of a mixture of the materials of said group.
Claim 6
Dependent Claim
19 words
Optical filter according to claim 1, in which said dispersed powder has a grain size smaller than 60 micrometers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |