EP0609093A1
Expired / Lapsed
EP
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Negative abbe number radial gradient index relay, method of making, and use of same
Assignee: Gradient Lens Corp
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Filing: 1994-01-28
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Granted: —
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Expires: 2014-01-28
Abstract
Abstract Radial gradient index of refraction (GRIN) optical relays for overcorrecting axial chromatic aberration and a method for their manufacture are described. A relay including a radial GRIN rod in combination with a holographic optical element, or simple homogeneous or GRIN lenses, is described for adjusting axial chromatic and monochromatic aberrations, including spherical, coma, astigmatism, and distortion. The invention also describes remote viewing scopes, such as endoscopes and borescopes, which utilize said relays for achromatic, and reduced or corrected monochromatic aberration imaging. The use of segmented said relays provides a slight degree of flexibility in certain remote viewing scopes. A method for producing an exemplary negative dispersion GRIN lens is disclosed.
Inventors
- 👤 Leland G. Atkinson Iii
- 👤 Douglas S. Kindred
- 👤 Raymond J. Hensler
- 👤 Duncan T. Moore
- 👤 Robert J. Zinter
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 05:52
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/24; A; A61; A61B; A61B1/00; A61B1/002; G02B23/2407; G02B23/2446; G02B27/00; G02B27/0025; G02B27/0037; G02B27/42; G02B27/4205; G02B27/4211; G02B27/4216; G02B3/00; G02B3/0087; G02B13/00; G02B13/22
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
35 words
An optical relay (35) for propagating an image (30) along an optical axis (20) including a radial gradient index of refraction component (24) characterised by a negative Abbe number, for reducing undercorrected axial chromatic aberration.
Claim 2
Dependent Claim
47 words
An optical relay (35) according to claim 1 wherein said radial GRIN component (24) has a first end face (32) and a second end face (36), in which each end face has a contour selected from the group consisting of: planar; spherical convex; spherical concave; and, aspherical.
Claim 3
Dependent Claim
24 words
An optical relay (35) according to claim 1 or 2 wherein said optical component has a negative Abbe number between about -∞, to -50.
Claim 4
Dependent Claim
25 words
An optical relay (35) according to claim 1, 2 or 3 wherein said optical component has a negative Abbe number between about -500 to -175.
Claim 5
Dependent Claim
81 words
An optical relay (35) according to any one of claim 1 to 4 wherein said radial GRIN component (24) has gradient index coefficients N 00c , N 00d , N 00F and N 10c , N 10d and N 10F in the gradient index profile expression Nλ(r) = N 00,λ + N 10,λ r² +..., as follows: N 00c = 1.531100 N 10c = -0.1600E-02 N 00d = 1.534200 N 10d = -0.1597E-02 N 00F = 1.540900 N 10F = -0.1591E-02
Claim 6
Dependent Claim
38 words
An optical relay (35) according to any one of claims 1 to 5 wherein the radial GRIN lens (27) is in optical combination with a holographic optical element (42) for overcorrecting axial chromatic aberration in a transmitted image.
Claim 7
Dependent Claim
51 words
Remote viewing scope (120) including an optical relay (35) according to any preceeding claim wherein said GRIN component (24) further comprises a plurality of conventional optical components having net undercorrected axial chromatic aberration whereby a final image (30) transmitted by the remote viewing scope is substantially corrected for axial chromatic aberration.
Claim 8
Dependent Claim
28 words
A remote viewing scope according to claim 7, wherein said plurality of conventional optical components further comprise an objective (70) which is telecentric to the optical relay (35).
Claim 9
Dependent Claim
154 words
The remote viewing scope of claim 7 or 8 in which the objective (70) comprises a first refractive element D₁ having a first refracting surface d₁ and a second refracting surface d₂, an aperture stop substantially in contact with surface d₁, and a second refractive element D₂ having a first refracting surface d₃ immediately adjacent surface d₃ and a second refracting surface d₄, the refracting surfaces each having a radius of curvature r₁, r₂, r₃ and r₄, respectively; each element having a thickness tD1, tD₂, respectively; and each element having refractive indices n c , n d and n F , as follows: Element Radius of curvature Thickness (mm) Index D₁ r₁ = infinity tD₁ = 3.950000 n c = 1.617272 n d = 1.620409 n F = 1.627560 r₂ = -3.20000 D₂ r₃ = 3.20000 tD₂ = 3.950000 n c = 1.617272 n d = 1.620409 n F = 1.627560 r₄ = infinity
Claim 10
Dependent Claim
24 words
The remote viewing scope (120) of claim 6, 7 or 8 in which the plurality of conventional optical components comprise a coupler lens (140).
Claim 11
Dependent Claim
18 words
The remote viewing scope of claim 10 in which the coupler lens (140) comprises a Petzval lens configuration.
Claim 12
Dependent Claim
18 words
The remote viewing scope of claim 10 in which the coupler lens (140) comprises a two doublet configuration.
Claim 13
Dependent Claim
22 words
The remote viewing scope of claim 10 in which the coupler lens (140) comprises a radial GRIN lens having overcorrected axial colour.
Claim 14
Dependent Claim
133 words
The remote viewing scope of claim 10 in which the coupler lens (140) comprises a first refractive element C₁ having a first refracting surface c₁ and a second refracting surface c₂, a second refractive element C₂ having a first refracting surface c₃ immediately adjacent surface c₂ and a second refracting surface c₄, and a third refractive element C₃ having a first refracting surface c₅ immediately adjacent surface c₄ and a second refracting surface c₆, the refracting surfaces each having a radius of curvature rc₁, rc₂, rc₃, rc₄, rc₅ and rc₆, respectively; each element having a thickness tC₁, tC₂ and tC₃, respectively; C₁ and C₃ each having refractive indices n c , n d and n F , and C₂ having refractive indices n c , n d and n F , as follows:
Claim 15
Independent Claim
115 words
A method for producing a GRIN lens having low dispersion wherein the improvement comprises the steps of: a) providing a host glass having the form (X)Na₂O + (Y)Li₂O + (Z)R m O n + (100-X-Y-Z)SiO₂, where X, Y and Z represent mole % amounts, where Z is selected such that the gradient Abbe number of the host glass, after a concentration profile is created therein, is in one of a range between negative infinity to about -50 and the dispersion of the host glass is in the range between about 0.009 to 0.012; and b) creating a concentration profile of Li+ and Na+ ions in the base glass to produce a radial gradient index profile.
Claim 16
Dependent Claim
51 words
The method of claim 15 in which the step b) comprises the step of introducing the base glass into a supply of molten salt including Na⁺ ions for a sufficient time to allow ion exchange between the Li+ ions in the base glass and the Na⁺ ions in the molten salt.
Claim 17
Dependent Claim
20 words
The method of claim 15 or 16 in which (X)Na₂O + (Y)Li₂O equals an amount between about 20% to 40%.
Claim 18
Dependent Claim
35 words
The method of claim 15, 16 or 17 in which the ratio of Li₂O: Na₂O is in the range between about 1/6:1/2, for producing a gradient index glass having a nearly parabolic refractive index profile.
Claim 19
Dependent Claim
51 words
The method of claim 15, 16, 17 or 18 in which R m O n is selected from a group consisting of TiO₂, ZrO₂, HfO₂, GeO₂, Al₂O₃, Ga₂O₃, Y₂O₃, La₂O₃, Ta₂O₅, Nb₂O₅, W₂O₆, PbO, BaO, CaO, ZnO, SrO, MgO, and other metal oxides which increase the dispersion of the host glass.
Claim 20
Independent Claim
25 words
The method of any one of claims 15 to 19 in which (Z)R m O n equals a total amount between about 1% and 15%.
Claim 21
Independent Claim
49 words
The method of any one of claims 15 to 20 in which (Z)R m O n comprises at least one of TiO₂ in an amount between about 0 to 6%, ZrO₂ in an amount between about 0% to 10%, and Al₂O₃ in an amount between about 0% to 10%.
References Cited (Backward Citations)
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