US4215914A
Expired / Lapsed
US
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Optical system having a radial difference in refractive index
Assignee: Carl Zeiss AG
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Filing: 1978-12-12
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Granted: 1980-08-05
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Expires: 1998-12-12
Abstract
Abstract An optical system in which at least one of the elements is made from so-called gradient glass having a radial difference in refractive index. The element having this radial difference may be either a lens with at least one curved surface, or a plane-parallel plate. The radial variation in refractive index varies in accordance with a formula which is given.
Inventors
- 👤 Franz Muchel
- 👤 Fritz Strahle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:29
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0087; G02B27/00; G02B27/18; G02B5/00; G02B5/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
An optical system having at least one element of so-called gradient glass having a radial difference in refractive index, characterized by the fact that the radial difference in refractive index of said element is substantially in accordance with the formula n=n.sub.o ·e.sup.Kh wherein the independent variable h represents the radial distance of a point of the optical element from the central axis of such element, the dependent variable n represents the index of refraction of the element at that point, K represents a constant material-dependent factor of the gradient glass element, and n o is the index of refraction of the gradient glass element on its central axis, and e represents the irrational number 2,7182818.
Claim 2
Dependent Claim
115 words
An optical system having at least one element of so-called gradient glass having a radial difference in refractive index, characterized by the fact that the radial difference in refractive index of said element is substantially in accordance with the formula n=n.sub.o ·e.sup.Kh wherein the independent variable h represents the radial distance of a point of the optical element from the central axis of such element, the dependent variable n represents the index of refraction of the element at that point, K represents a constant material-dependent factor of the gradient glass element, and n o is the index of refraction of the gradient glass element on its central axis, and e represents the irrational number 2,7182818.
Claim 3
Dependent Claim
51 words
An optical system according to claim 1, characterized by the fact that the element with radial difference in index of refraction is positioned at a place in the optical system where the aperture rays imaging an axial image point are of lesser height than the rays imaging an off-axis image point.
Claim 4
Dependent Claim
32 words
An optical system according to claim 2, characterized by the fact that the element with radial difference in refractive index is developed as a lens having at least one curved limiting surface.
Claim 5
Dependent Claim
26 words
An optical system according to claim 1, characterized by the fact that the element with radial difference in refractive index is developed as a plane-parallel plate.
Claim 6
Dependent Claim
29 words
An optical system according to claim 4, characterized by the fact that a plane-parallel plate is provided in at least one of the air spaces of the optical system.
Claim 7
Dependent Claim
31 words
An optical system according to claim 4, characterized by the fact that a plane-parallel plate with radial difference in refractive index is arranged behind the last optical surface of the system.
Claim 8
Dependent Claim
35 words
An optical system according to either claim 3 or claim 4, characterized by the fact that the element with radial difference in refractive index is arranged in the vicinity of the locus of the diaphragm.
References Cited (Backward Citations)
US1943521A
Cited
US2547416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-05 | 1984-02-04 | 1984-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-05 | 1988-02-04 | 1988-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-05 | 1992-02-04 | 1992-08-05 | $7700.00 | Window Closed / Lapsed |