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US 4,061,419 AGranted
Variable magnification lens system
AssigneeXerox Corporation
InventorsEdgar Elmer Price, Louise Leone Spurles
Life of this patent
Estimating the term…
Abstract
A variable magnification lens is exemplified by a 6-element symmetrical zoom lens for use between fixed conjugates at magnification ranging from 1.007X to 0.615X. The outer elements remain fixed relative to the unit. The inner elements form two integral pairs on each side of the central aperture and move symmetrically with respect to it to effect magnification change while maintaining a substantially flat image field over the entire magnification range.
Claims6
A variable magnification lens including the following lens elements in alignment along an optical axis:
- a front positive crown element,
- a front negative flint element spaced from said crown element,
- a front meniscus element spaced from said flint element,
- a back meniscus element spaced from said front meniscus element,
- a back negative flint element spaced from said back meniscus element,
- a back positive crown element spaced from said back flint element,
- said crown elements being fixed relative to each other,
- said flint and meniscus elements being movable along said optical axis to vary the focal length of said lens.
5 more elements
A variable magnification lens including the following lens elements in alignment along an optical axis:
- a front positive crown element,
- a front negative flint element spaced from said crown element,
- a front meniscus element spaced from said flint element,
- a back meniscus element spaced from said front meniscus element,
- a back negative flint element spaced from said back meniscus element,
- a back positive crown element spaced from said back flint element,
- said crown elements being fixed relative to each other,
- said front flint and front meniscus elements together forming an integral pair,
- said back flint and back meniscus elements together forming an integral pair,
- at least one of said pairs being movable along said optical axis relative to said crown elements to vary the focal length of said lens.
7 more elements
A variable magnification lens including the following lens elements in alignment along an optical axis:
- a front positive crown element,
- a front negative flint element spaced from said crown element,
- a front meniscus element spaced from said flint element,
- a back meniscus element spaced from said front meniscus element,
- a back negative flint element spaced from said back meniscus element,
- a back positive crown element spaced from said back flint element,
- said crown elements being fixed relative to each other,
- said flint and meniscus elements being movable along said optical axis to vary the focal length of said lens,
- the parameters of lens radii (R) thicknesses (T) spacings (S) refractive indices (N.sub.d) and dispersion values (V.sub.d) being in accordance with the following table wherein radii, thicknesses, and spacings are expressed in inches and a negative sign indicates lens radii on centers of curvature on the object side of the lens:
- ______________________________________ Thick- ness Lens Radius (R) (T) Spacing (S) N.sub.d V.sub.d ______________________________________ 4 R.sub.1 2.50358 R.sub. 2 31.64727 T.sub.4.72176 1.5891 61.27 S.sub.1 (1.007X) .05202 (0.800X) .06872 (0.615X) .13403 6 R.sub.3 37.17555 R.sub.4 1.99482 T.sub.6.29455 1.5919 48.51 S.sub.2 .37619 8 R.sub.5 3.58139 R.sub.6 6.15101 T.sub.8.30862 1.6031 60.60 S.sub.3 (1.007X) .83602 (0.800X) .80262 (0.615X) .67198 10 R.sub.7 -6.15101 R.sub.8 -3.58139 T.sub.10.30862 1.6031 60.60 S.sub.4 .37619 12 R.sub.9 -1.99482 R.sub.10 -37.17555 T.sub.12.29455 1.5919 48.51 S.sub.5 (1.007X) .05202 (0.800X) .06872 (0.615X) .13403 14 R.sub.12 -31.64727 R.sub.14 -2.50358 T.sub. 14.72176 1.5891 61.27 ______________________________________
7 more elements
A variable magnification lens including the following lens elements in alignment along an optical axis:
- a front positive crown element,
- a front negative flint element spaced from said crown element,
- a front meniscus element spaced from said flint element,
- a back meniscus element spaced from said front meniscus element,
- a back negative flint element spaced from said back meniscus element,
- a back positive crown element spaced from said back flint element,
- said crown elements being fixed relative to each other,
- said flint and meniscus elements being movable along said optical axis to vary the focal length of said lens,
- the parameters of lens radii (R) thicknesses (T) spacings (S) refractive indices (N.sub.d) and dispersion values (V.sub.d) being in accordance with the following table wherein radii, thicknesses, and spacings are expressed in inches and a negative sign indicates lens radii on centers of curvature on the object side of the lens:
- ______________________________________ Thick- ness Lens Radius (R) (T) Spacing (S) N.sub.d V.sub.d ______________________________________ S.sub.0 (1.007X) 24.94296 (0.800X) 28.07371 (0.615X) 31.56181 4 R.sub.1 2.50358 R.sub.2 31.64727 T.sub.4.72176 1.5891 61.27 S.sub.1 (1.007X) .05202 (0.800X) .06872 (0.615X) .13403 6 R.sub.3 37.17555 R.sub.4 1.99482 T.sub.6.29455 1.5919 48.51 S.sub.2 .37619 8 R.sub.5 3.58139 R.sub.6 6.15101 T.sub.8.30862 1.6031 60.60 S.sub.3 (1.007X) .83602 (0.800X) .80262 (0.615X) .67198 10 R.sub.7 -6.15101 R.sub.8 -3.58139 T.sub.10.30862 1.6031 60.60 S.sub.4 .37619 12 R.sub.9 -1.99482 R.sub.10 -37.17555 T.sub.12.29455 1.5919 48.51 S.sub.5 (1.007X) .05202 (0.800X) .06872 (0.615X) .13403 14 R.sub.12 -31.64727 R.sub.14 -2.50358 T.sub.14.72176 1.5891 61.27 S.sub.I (1.007X) 25.13348 (0.800X) 22.00273 (0.615X) 18.51462 ______________________________________
7 more elements
Dependencies are inferred from the claim text.