US4145113A
Expired / Lapsed
US
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Color correcting interference filter
Assignee: C Reichert Optische Werke AG
•
Filing: 1977-08-05
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Granted: 1979-03-20
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Expires: 1997-08-05
Abstract
Abstract An interference filter having a plurality of alternating layers of high and low index of refraction and layer thickness increasing toward the center can compensate for errors in spectral energy distribution produced by an optical system.
Inventors
- 👤 Guenther Ranninger
- 👤 Franz Twaroch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:12
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
142 words
In an instrument having a light source with a chosen spectral energy distribution, an optical system including optical elements that change the energy distribution of light passing therethrough and detection means responsive to light, the detection means being adapted to respond in a given manner to said chosen energy distribution, the improvement comprising an interference filter having a transparent substrate and nine alternating layers of first and second dielectric coating materials; said first material having a given index of refraction; said second material having an index of refraction of about 1.5 times said given index of refraction; the first and ninth layers having a thickness of λ o /16, the second and eighth layers having a thickness of λ o /8 and the remaining layers having a thickness of λ o /4 and where 480 nm ≦ λ o ≦ 670 nm.
Claim 2
Dependent Claim
142 words
In an instrument having a light source with a chosen spectral energy distribution, an optical system including optical elements that change the energy distribution of light passing therethrough and detection means responsive to light, the detection means being adapted to respond in a given manner to said chosen energy distribution, the improvement comprising an interference filter having a transparent substrate and nine alternating layers of first and second dielectric coating materials; said first material having a given index of refraction; said second material having an index of refraction of about 1.5 times said given index of refraction; the first and ninth layers having a thickness of λ o /16, the second and eighth layers having a thickness of λ o /8 and the remaining layers having a thickness of λ o /4 and where 480 nm ≦ λ o ≦ 670 nm.
Claim 3
Dependent Claim
62 words
The improvement according to claim 1 wherein the interference filter has the following parameters: ______________________________________
Layer Refractive Index
Material Layer-Thickness (nm)
______________________________________
1 2.05 ZrO.sub.2
35
2 1.38 MgF.sub.2
70
3 2.05 ZrO.sub.2
140
4 1.38 MgF.sub.2
140
5 2.05 ZrO.sub.2
140
6 1.38 MgF.sub.2
140
7 2.05 ZrO.sub.2
140
8 1.38 MgF.sub.2
70
9 2.05 ZrO.sub.2
35
Substrate
1.52 Glass
______________________________________
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) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |