SU1748124A1 - Oil immersion microscope objective - Google Patents

Abstract

Usage: in optical instrument making, namely in various types of microscopes and as a lens for microphotographs. SUMMARY OF THE INVENTION: An oil immersion microscope objective contains five components, the first and second of which are flat-convex lenses, the power ratio of the two first components being 0.85: 2.29f1, the third is a positive meniscus glued together from negative and positive lenses, reversed concavity to the space of objects, the fourth - glued positive lens, including negative and positive lenses, the fifth component is made in the form of gluing a positive meniscus, facing the concavity to the object, and two lenses, the difference of the refractive indices of the lens material of the fifth component does not exceed 0.01, and the coefficient of the average dispersion of the material of the double forked lens exceeds the coefficient of the average dispersion of the material of the positive meniscus of the fifth component by no less than 22, where f is the objective focal length. 1 il.

Description

The invention relates to optical instrument making, namely to immersion lenses of microscopes, and can be used in various types of microscopes and as an objective for micrographs.

The oil immersion microscope objective is known, which contains four components, the first of which is a flat convex lens, the second is a single positive meniscus facing the concavity of the object, and the third and fourth are glued positive lenses, consisting of negative and positive lenses, glued are inserted behind the fourth component component consisting of plane-convex and

concave lens, and the coefficient of the average dispersion of the concave lens is greater than the coefficient of average dispersion of the plane-convex lens.

The closest to the present invention is an oil immersion microscope objective, containing five components, the first of which is a flat convex lens, the second is a single positive meniscus facing concavity to the space of the object, the third and fourth are glued positive lenses, including negative and positive lenses, and the fifth one is the glued component, the third component is made in the form of a meniscus with a concavity facing the space of 2

00

to

The fifth component is made in a co-convex and double-concave lenses.

However, a known lens does not provide the required image quality.

The aim of the invention is to improve the correction of aberrations while eliminating the increase chromatism.

The goal is achieved by the objective of an oil immersion microscope lens containing five components, the first of which is a flat-issue lens, the second is a positive lens, the third is a positive meniscus glued from negative and positive lenses, facing the space of objects, the fourth

- a glued positive lens, including a negative and a positive lens, and the fifth is a glued component, the second component is made in the form of a flat-convex lens, the ratio of the forces of the two First components is 0.83 - 2.29G, the fifth component is made in the form of gluing a positive meniscus facing concavity to the object, and a double-bent lens, the difference of the refractive indices of the lens material of the fifth component does not exceed 0.01, and the coefficient of the average dispersion of the material of the double-bent lens exceeds the average dispersion coefficient uu positive meniscus fifth component material is not less than 22, where f 1

-focal lens distance.

In the proposed large-aperture oil immersion microscope, it is necessary to correct the spherical aberration, the spherochromatism, and the chromatism of the position, for which the component in the bent convex lens, simple to manufacture, is used in the frontal part of the objective.

For correcting the curvature of the image, astigmatism and chromaticity magnification across the field in the lens, a double-concave lens, glued from a positive meniscus with a concavity facing the object and a double-concave lens, is used as the fifth component.

In order to improve the chromatism correction, the difference in the refractive indices of the lens material of the fifth component does not exceed 0.01, and the coefficient of the average dispersion of the material of the double-curved lens exceeds the coefficient of the average dispersion of the positive meniscus material of the fifth component by no less than 22.

In the above version of the calculation, the oil immersion microscope objective has the following aberrations: the transverse spherical aberration for a point on the axis in the entire spectral range does not exceed 0.19 mm at the edge of the pupil and 0.043 mm at the zone.

Wave pupil aberration is equal to hapEF1С1

1.0-0.62 0.006 -0.15

0.866 -0.40 0.046 -0.032 0.707 -0.22 0.007 -0.010 0.5-0.07 0.006 -0.010

O000

From the presented table of wave aberrations, it follows that the chromatism of the position and spherochromatism are corrected in the lens of the oil immersion microscope.

The chromatism of the increase over the entire field does not exceed 0.01%, which is negligible.

The image curvature in astigmatism is equal to:

edge floor Zt -24.4 mm; Zs -26,6 mm .; g5 - g -2,2mm;

Zt zone -12.43 mm: Zs -14.3 mm; Zs -Zt -1.87 mm.

The drawing shows the proposed device.

In the drawing, the following notation is accepted: 1 and 2 — flat-convex lenses; 3 - a positive meniscus reversed by the concavity k of an object glued together from a negative double-concave lens 4 and a positive double-convex lens 5; 6 - positive lens, glued from negative 7 and 8 positive lenses; 9 is a glued set consisting of a positive meniscus 10, facing the concavity to the object, and a double-concave lens 11.

The object is in front of the microscope lens at a distance somewhat larger than its focal length. Therefore, a diverging beam of light falls on the lens, which sequentially passes through components 1, 2, 3, 6, 9 and in the image plane creates an enlarged, inverted, real image of the object. The aperture beam, which goes from the center of the object to the edge of the aperture diaphragm of the HELL of the lens, coincides with the given focal plane of the lens.

As a concrete example, an oil immersion microscope objective was designed with the following characteristics: linear magnification. 100 times the front aperture 1.25; front focal length, -2.72 mm; back focal length, 1.80 mm; field magnification chromaticity 0.01; lens height 45 mm; image size 20 mm; tube length 160 mm,

Claims (1)

The advantages of the oil immersion microscope objective are improved image quality and the lack of chromatic magnification, which allows the use of simple eyepieces and the use of a lens for microphotographs. Invention The oil immersion microscope objective contains five components, the first of which is a flat convex lens, the second - a positive lens, the third - a positive meniscus, glued from negative and positive lenses and facing concavity to the space of objects, the fourth - glued position A positive lens, including a negative and a positive lens, and a fifth — a glued component, including a positive and a double-curved lens, characterized in that, in order to improve the image quality, the second component is made in the form of a flat convex lens, the ratio of optical forces of the first two components being equal to 0, 83: 2,291, the positive lens of the fifth component is made in the form of a meniscus with concavity facing the space of objects; the difference in the refractive indices of the materials of the lens of the fifth component does not exceed 0.01, and the difference be the coefficients of the dispersion medium materials biconcave lens and a positive meniscus fifth component is at least 22. wherein the focal length f of the objective lens. 7 8 4S 9 L-