RU2010277C1 - Oil-immersion objective lens for microscope - Google Patents

Abstract

FIELD: optical instrumentation. SUBSTANCE: oil-immersion objective lens for microscope has single plano-convex lenses, collecting biconvex lens with equal radii, negative meniscus cemented from biconvex and biconcave lenses, second positive single biconvex lens, positive meniscus facing image space with concavity and cemented from convex- plano and plano-concave lenses and barrel lens. Focal distance 1.6 mm; magnification 100^x, front aperture 1.25; front working length 0.42 mm. EFFECT: increased operational characteristics. 3 dwg

Description

 The invention relates to optical instrumentation, namely to achromatic immersion lenses of microscopes.

 Known immersion microscope lens for the visible and ultraviolet regions of the spectrum, containing a positive front lens, a positive three-lens bonded component and a single positive lens, it introduced a single positive lens and a positive three-lens component installed after the front lens.

 Known achromatic lens with an increase of 100x1.25 oil immersion, which is designed for a tube length of 160 mm and the use of a glass cover, 0.17 mm thick. In fig. IV. 37 shows the optical design of this lens, which consists of a flat convex front lens, a positive meniscus facing concavity to the space of objects, and two double-glued components. In table IV. 10 shows the aberration of the lens. The chromaticity of the increase in this lens is 2%.

 As a prototype, an oil immersion microscope objective was selected that contains four components, the first of which is a plano-convex lens, the second is a single positive meniscus facing concavity to the object, and the third and fourth are a glued positive lens consisting of negative and positive lenses, behind the fourth component a glued component consisting of a plano-convex and concave-flat lenses is introduced, the coefficient of average dispersion of a concave-flat lens is greater than the coefficient of average dispersion of a plano-convex lens s.

 But this lens does not provide the required image quality and is not technologically advanced.

The essence of the invention lies in the fact that in the lens of the oil immersion microscope containing a plano-convex lens, a single positive lens, a first and second positive lenses and a glued component consisting of a plano-convex and plano-concave lenses, the average dispersion coefficient of the plano-concave lens exceeds the average dispersion coefficient of the plano-convex lens, a single positive lens is made plano-convex, the first positive lens is made a single biconvex with equal radii of curvature over nostrum, the second positive lens is made of a single biconvex, and between the first and second positive lenses introduced a negative meniscus glued from a biconvex and biconcave lenses, and the biconcave lens is made with equal radii of curvature of the surfaces, and the glued component is made in the form of a positive meniscus facing concavity to the space of images and installed at a distance from the second positive lens of at least 6 f _about , where f _about is the focal length of the lens.

 The purpose of the invention is improving image quality and improving the manufacturability of its design.

 A single positive lens is made convex and serves to correct spherical aberration of the third and higher orders for a point on the axis, as well as coma, in addition, it increases the manufacturability of the lens.

 The first positive lens is made of a single biconvex with equal radii of curvature of the surfaces, which is technologically advanced. The second positive lens is made of a single biconvex, the first and second single lenses provide correction of spherical aberration and coma in a wide inclined beam of rays in the meridional and sagittal sections.

 A negative meniscus glued from a biconvex and biconcave lenses is introduced between the first and second positive lenses, and the biconcave lens is made with equal radii of curvature of the surfaces, provides correction of image curvature, astigmatism, chromatic aberrations, especially chromaticity of position and spherochromatism, and also improves the manufacturability of the lens.

The glued component is made in the form of a positive meniscus, facing with a concavity to the image space and installed at a distance from the second positive lens of at least 6 f ' _rev , serves to correct image curvature, astigmatism and chromatic aberration, especially chromatic aberration.

The distance of 6 f ' _{about is} chosen experimentally and makes it possible to simultaneously correct the image curvature and the increase in chromatism.

 In FIG. 1 is an optical diagram of an oil immersion microscope lens with structural data, where 1,2 is a single plano-convex lens, 3 is the first positive biconvex lens with equal radii, 4 is a negative meniscus glued from biconvex 5 and biconcave 6 lenses, 7 is the second positive single biconvex lens, 8 - positive meniscus, facing concavity to the space of images and glued from a convex-flat 9 and plano-concave 10 lenses, 11 - tube lens.

 In FIG. 2 shows the aberration tables of a specific example of calculating the objective of an oil immersion microscope; in FIG. 3 - graphs of its aberrations.

An oil immersion microscope objective with the following optical characteristics was calculated as a specific example: Focal length of the lens, mm 1.6 Focal length of the tube lens, mm 160 Magnification 100 Front aperture 1.25 Front working distance, mm 0.42 Distance from the lens plane to the last lens surface, mm 25.94
The oil immersion microscope lens has the following image quality.

 Transverse spherical aberration for a point on the axis does not exceed 0.3 mm (on the very edge of the pupil) and 0.018 mm (on the zone) for the main wavelength and 0.3 mm in the entire spectral range.

The wave aberrations for a point on the axis throughout the pupil are equal to: h _sp.rel . l F 'C' 1.0 -0.230 0.641 0.594 0.866 -0.152 0.440 0.445 0.707 -0.137 0.224 0.295 0.5 -0.052 0.112 0.188 0 0 0 0
The coefficient of neusoplanasia does not exceed 0.2% throughout the pupil.

Image curvature and astigmatism are equal: y = -0.16 Z ' _t = -12.48 Z' _s = -12.07 Z ' _s -Z' _t = -0.41 y = -0.11 Z ' _t = -6.32 Z ' _s = -6.08 Z' _s -Z ' _t = -0.24
The chromaticity of the increase is 0.28%.

 The mean square wave aberration for a point on the axis is 0.097λ.

The mean square wave aberration over the field in the plane of the best setting is equal to: y 'W _sr. 10. 0.229 8.66 0.195 7.07 0.165 5.0 0.127 0 0.097
The value of the mean-square wave aberration in the spectral interval, field and pupil is equal to: without defocusing and distortion - 0.353 λ; excluding defocusing, image curvature and distortion - 0.099 λ. (56) Panov V.A. and Andreev L.N. Optics of microscopes. L.: Engineering, 1976, p. 117-121, fig. IV. 37.

 USSR author's certificate N 1101771, cl. G 02 B 21/02, 1983.

Claims (1)

 OIL IMMERSION MICROSCOPE LENS, containing a plano-convex lens, a single positive lens, a first and second positive lenses and a glued component, consisting of a plano-convex and plano-concave lenses, moreover, the coefficient of average dispersion of a plano-plano-lens lens image quality while increasing the design technology, in the lens a single positive lens is made convex, the first positive lens is od a night biconvex with equal radii of curvature of the surfaces, a second positive lens - a single biconvex, and also between the first and second positive lenses introduced a negative meniscus glued from a biconvex and biconcave lens, with a double-curved lens positive meniscus, turned concavity to the space of images, and installed at a distance from the second positive lens, at least six focal lengths of the objects willow.

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