Infrared continuous zoom telescope using diffractive optics
First Claim
1. A color correcting lens system comprising:
- (a) a zoom afocal lens system including;
(i) an objective lens;
(ii) an eyepiece lens;
(iii) a plurality of lenses disposed between said objective lens and said eyepiece lens; and
(iv) a diffractive pattern disposed at a surface of said objective lens to provide color correction at a predetermined wavelength of light passing therethrough;
(b) all of said lenses of said system being germanium lenses.
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Accused Products
Abstract
An infrared continuous zoom telescope or afocal lens system using a diffractive surface for color correction. The lens system comprises an objective lens, an eyepiece lens, a plurality of lenses disposed between the objective lens and the eyepiece lens to provide the zoom function and a diffractive pattern disposed at a surface, preferably the interior surface and preferably integral therewith, of the objective lens to provide color correction at a predetermined wavelength of light passing through the objective lens. All of the lenses are preferably germanium. The diffractive pattern comprises a plurality of spaced ring-shaped steps, each ring concentric with the center of the objective lens and each step having a height equal to the predetermined wavelength for which the lens system is designed. The plurality of ring-shaped steps are formed in accordance with a known formula.
43 Citations
18 Claims
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1. A color correcting lens system comprising:
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(a) a zoom afocal lens system including; (i) an objective lens; (ii) an eyepiece lens; (iii) a plurality of lenses disposed between said objective lens and said eyepiece lens; and (iv) a diffractive pattern disposed at a surface of said objective lens to provide color correction at a predetermined wavelength of light passing therethrough; (b) all of said lenses of said system being germanium lenses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A color correcting lens system comprising:
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(a) a zoom afocal lens system including; (i) an objective lens; (ii) an eyepiece lens; (iii) a plurality of lenses disposed between said objective lens and said eyepiece lens; and (iv) a diffractive pattern disposed at a surface of said objective lens to provide color correction at a predetermined wavelength of light passing therethrough, said diffractive pattern comprising a plurality of spaced ring-shaped steps, each ring concentric with the center of said objective lens and each step having a height equal to said predetermined wavelength said plurality of ring-shaped steps being formed in accordance with the formula ##EQU2## where;
Z is Sag value along the z-axis or optical axisY is the semi-diameter height CC is the base curvature (i/radius) of the surface K is the conic coefficient of the surface A, B, C and D are the 4th, 6th, 8th and 10th order aspheric coefficients, respectively HOR is the diffraction order, generally 1 or -1 λ
is the design wavelength for the surfaceN1 is the refractive index of the material preceding the diffractive surface N2 is the refractive index of the material following the diffractive surface C1, C2 and C3 are coefficients for describing aspheric phase departure INT is an integer function; (b) all of said lenses of said system being germanium lenses. - View Dependent Claims (14, 15, 16)
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17. A color correcting objective lens comprising:
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(a) a germanium objective lens; and (d) a diffractive pattern disposed at a surface of said objective lens to provide color correction at a predetermined wavelength of light passing therethrough, said diffractive pattern comprising a plurality of spaced ring-shaped steps, each ring concentric with the center of said objective lens and each step having a height equal to said predetermined wavelength, said plurality of ring-shaped steps being formed in accordance with the formula ##EQU3## where;
Z is Sag value along the z-axis or optical axisY is the semi-diameter height CC is the base curvature (i/radius) of the surface K is the conic coefficient of the surface A, B, C and D are the 4th, 6th, 8th and 10th order aspheric coefficients, respectively HOR is the diffraction order, generally 1 or -1 λ
is the design wavelength for the surfaceN1 is the refractive index of the material preceding the diffractive surface N2 is the refractive index of the material following the diffractive surface C1, C2 and C3 are coefficients for describing aspheric phase departure INT is an integer function. - View Dependent Claims (18)
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Specification