RU1781661C - Achromatic lens of microscope - Google Patents

Abstract

Usage: the invention relates to the field of optical instrumentation, namely to achromatic lenses of microscopes. The inventive lens contains a single plano-convex lens and three double-glued lenses, the first and second of which are two-convex, containing a negative meniscus and a two-convex lens, and the third is a negative meniscus, including a double-convex and two-concave lens, located at a distance of at least 2f from the second component and made of materials, the difference in the refractive indices of which is not less than 0.15, and the difference in the coefficients of the average dispersions is not more than 15, where f is the focal length of the lens. 3 ill.

Description

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

A micro-lens is known, containing two positive components separated by an air gap, and an image curvature compensator, a positive frontal lens is installed in front of the image curvature compensator, the first surface of which is flat, the second aplanatic, the image curvature compensator is made in the form of a glued meniscus with external aplinic surfaces, facing concavity to the object, while the optical power of the curvature compensator is 0.5-0.7 optical power of the entire micro lens, p z- NOSTA dispersion compensator lens glasses coefficient is not less than 15, and the positive component disposed directly behind the curvature compensator

made in the form of a biconvex taped lens.

Achromatic microscope objective is known, consisting of a plano-convex frontal lens and two positive bonded components, consisting of a positive and negative lenses, the dispersion coefficient of the positive lens of each bonded component is greater than the dispersion coefficient of the negative lens in each of these components, a double-glued component is inserted between the bonded components component consisting of positive and negative lenses, and the dispersion coefficient of the positive lens is less than the coefficient the dispersion of the negative lens, and the gluing surface is turned concavity to the space of objects; the positive lens of the double-glued component is made in the form of a plano-convex lens

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As a prototype, an achromatic microscope lens was chosen, containing a single lens and three double-glued components, the first of which contains a negative meniscus facing concavity to the image and a positive lens, the second contains a positive lens and negative meniscus facing concavity to the object, and the third is made in in the form of a negative meniscus facing concavity to the image and including biconvex and biconcave lenses.

But the specified lens does not provide the required image quality,

The aim of the invention is to improve image quality with eliminated chromaticity magnification,

The essence of the invention lies in the fact that the microscope objective is achromatic, containing a single lens and three double-glued components, the first of which contains a negative meniscus facing concavity to the image and a positive lens, the second contains a positive lens and negative meniscus facing concavity to the object, and the third is made in the form of a negative meniscus facing concavity to the image and includes biconvex and biconcave lenses, a single lens is made convex, the third is double einy component is located at a distance of not less than 2f and the second component is made of a material whose refractive index difference of not less than 0.15 and the difference coefficients dispersion medium is not more than 15, wherein f - lens focal distance,

A single lens is made in the form of a plano-convex and serves to correct spherical aberration of the third and higher orders for a point on the axis and for off-axis bundles, for correcting spherochromatism.

A distance between the second and third components of at least 2 was chosen experimentally and serves to correct the spherical aberration and coma of wide inclined beams of rays in the meridional and critical sections.

I will examine the presence of glasses in GOST 13659-78, we will see that for the correction of chromatic aberrations, especially chromaticity increase, for the correction of the image curvature, the difference in the refractive indices of the lenses of the third component is not less than 0.15, and the difference in the coefficients of the average dispersions is not more than 15.

Transverse spherical aberration for a point on the axis for the main wavelength

does not exceed 0.017 mm, and in the entire spectral range - 0.063 mm.

Image curvature and astigmatism are equal:

y -0.25 mm z t -3.28 mm z s -6.38

mm z s -z t -3.1 mm

y -0.184mm z t -1.65MM z s -3.22 MM z s - z t -1.57 MM

Chromatism of magnification over the field together with the tube lens does not exceed 0.21%.

The mean-square wave aberration in the plane of the best installation in the field is:

at Wcp.KB

10 0.130

8,660,110

7,070,094

5,00,083

00,080

The value of the mean-square wave aberration in the spectral interval, field and pupil is equal to:

excluding defocusing and distortion 0.171 I.

excluding defocusing, distortion and curvature of the image 0.089 I.

Strehl number in the field is

y 10 8.66 7.07 500 Strehl number 0.57 0.66 0.74 0.79 0.80

In FIG. 1 is an optical diagram of an achromatic microscope objective lens with design parameters, where 1 is a single plano-convex lens, 2, 3, 4 are the first, second, and third double-glued components, respectively, 5 is the negative meniscus of the first component, facing the concavity to the image space, 6 - two convex convex lenses of the first glued component, 7 — two convex convexes, 8 — negative meniscus of the second glued component, 9 two convex convexes, 10 — two lenses of the third glued component are bent, 11 — tube tube lens; in FIG. 2 is a table of aberrations of the objective of an achromatic microscope: in FIG. 3 - graphs of its aberrations.

The achromatic microscope objective is designed for infinity tube length. The object is placed in the front focal plane, so a diverging beam of rays falls on it, which is a follower

but it passes through all the components of lens 1. 2 3 and 4 (see Fig. 1) and creates an image of the object at infinity, which the tube lens 11 is transferred to the focal plane of the eyepiece

As a specific example, an achromatic microscope objective with the following optical characteristics was calculated:

Magnification40

Front Aperture: 0.65

Tube Length Infinity

Distance from the plane of objects to the last surface of the lens, mm 26.27 Front working segment, mm 0.6 Image size, mm 20

Claims (1)

The claims Achromatic microscope lens, containing a single lens and three double-glued components, the first of which contains negative meniscus, facing 0 a concave to the image and a positive lens, the second a positive lens and a negative meniscus facing concavity to the object, and the third is made in the form of a negative meniscus facing concavity to the image and includes a double-convex and double-concave lenses, characterized in that, for the purpose of image enhancement with eliminated enlargement chromatism, a single lens is made convex, the third double-glued component is located at least 2f from the second component and is made of material fishing, the difference in the refractive indices of which is not less than 0.15, and the difference in the coefficients of the average dispersions is not more than 15, where f is the focal length of the lens. Fie. 1 zo / 770ZA42. n & axis / / net / za. & w & sem MQot / $ t / oH € j 6 & e e eeveHt / g 3cgs tnt QJ6UO & & ЈҐ & No. / & qoc / z. L -4.0 ° C AS -, ° 0.1 V ° A  ELR 1,0 -f.O - /, 0