Patent US4940636A successfully refreshed from Google Patents.
US4940636A
Expired / Lapsed
US
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Optical interference filter
Assignee: US Philips Corp
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Filing: 1988-07-21
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Granted: 1990-07-10
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Expires: 2008-07-21
Abstract
Abstract The optical interference filter is assembled from alternating amorphous SiO 2 layers and layers made of mixed oxides chosen from 88-95 mole.% TiO 2 and 5-12 mole.% ZrO 2 , 88-95 mole.% TiO 2 and 5-12 mole.% HfO 2 , TiO 2 .ZrO 2 .HfO 2 , TiO 2 .Nb 2 O 5 TiO 2 .Ta 2 O 5 and Ta 2 O 5 . 2TiO 2 . The mixed oxides have a crystal structure which corresponds to the crystal structure obtained after a heat treatment between 700 and 1100° C. The filter is stable, also after a long period at an elevated temperature.
Inventors
- 👤 Lieselotte Brock
- 👤 Gunter Frank
- 👤 Bruno Vitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:55
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285; C; C03; C03C; C03C17/00; C03C17/34; C03C17/3411; C03C17/3417; C03C2217/00; C03C2217/70; C03C2217/73; C03C2217/734
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
161 words
An optical interference filter having an alternating sequence of first low-refractive index layers and second high-refractive index layers on a glass substrate, the first layers consisting essentially of amorphous SiO 2 and the second layers being crystalline layers and consisting essentially of TiO 2 and a second metal oxide, characterized in that the material of the second layers is a mixed oxide chosen from a group consisting of: 88-95 mole. % TiO 2 and 5-12 mole. % ZrO 2 , 88-95 mole. % TiO 2 and 5-12 mole. % of an oxide selected from the group HfO 2 , TiO 2 .ZrO 2 , TiO 2 .HfO 2 , TiO 2 .Nb 2 O 5 , TiO 2 .Ta 2 O 5 and Ta 2 O 5 .2TiO 2 and mixtures or combinations of these materials, the crystal structure of the second layers corresponding to a crystal structure obtained in a heat treatment at a temperature between 700° and 1100° C.
Claim 2
Dependent Claim
161 words
An optical interference filter having an alternating sequence of first low-refractive index layers and second high-refractive index layers on a glass substrate, the first layers consisting essentially of amorphous SiO 2 and the second layers being crystalline layers and consisting essentially of TiO 2 and a second metal oxide, characterized in that the material of the second layers is a mixed oxide chosen from a group consisting of: 88-95 mole. % TiO 2 and 5-12 mole. % ZrO 2 , 88-95 mole. % TiO 2 and 5-12 mole. % of an oxide selected from the group HfO 2 , TiO 2 .ZrO 2 , TiO 2 .HfO 2 , TiO 2 .Nb 2 O 5 , TiO 2 .Ta 2 O 5 and Ta 2 O 5 .2TiO 2 and mixtures or combinations of these materials, the crystal structure of the second layers corresponding to a crystal structure obtained in a heat treatment at a temperature between 700° and 1100° C.
Claim 3
Dependent Claim
28 words
An optical interference as claimed in claim 1 wherein said material of the second layer is 88-95 mole % TiO 2 and 5-12 mole % ZrO 2 .
Claim 4
Dependent Claim
28 words
An optical filter as claimed in claim 1 wherein said material of the second layer is 88-95 mole % TiO 2 and 514 12 mole HfO 2 .
Claim 5
Dependent Claim
21 words
An optical filter as claimed in claim 1 wherein said material of the second layer is TiO 2 .ZrO 2 .
Claim 6
Dependent Claim
21 words
An optical filter as claimed in claim 1 wherein said material of the second layer is TiO 2 .HfO 2 .
Claim 7
Dependent Claim
23 words
An optical filter as claimed in claim 1 wherein said material of the second layer is TiO 2 .Nb 2 O 5 .
Claim 8
Dependent Claim
23 words
An optical filter as claimed in claim 1 wherein said material of the second layer is TiO 2 .Ta 2 O 5 .
Claim 9
Dependent Claim
23 words
An optical filter as claimed in claim 1 wherein said material of the second layer is Ta 2 O 5 .2TiO 2 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-09 | 1994-01-08 | 1994-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-09 | 1998-01-08 | 1998-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-09 | 2002-01-08 | 2002-07-10 | $7700.00 | Window Closed / Lapsed |