RU2497163C1 - Plan-apochromatic high-aperture microlens with long operating distance - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: microlens has five components arranged in series, the first of which is in form of a meniscus whose concave surface faces the object space. The second positive component is made from a glued biconvex lens and a negative meniscus whose concave surface faces the object space; the third double-glued component is made from a negative meniscus facing the image space with its concave surface, and a biconvex lens, and the fifth component is made from a single biconcave lens and two menisci facing the object space with their concave surfaces. The dispersion coefficient ν_d of the positive lenses of the second and third components and the meniscus situated behind the biconcave lens in the fifth component ν_d≥70, and the negative meniscus of the glued lens of the third and component and the biconcave lens of the fifth component have the dispersion coefficient 42≤ν_d≤48.

EFFECT: longer operating distance to enable operation with cuvettes and manipulators, as well as high input numerical aperture while maintaining plan-apochromatic correction.

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Description

The present invention relates to optical instrumentation, namely, microscope lenses, and can be used for visual observation and photographing of low-contrast microscopic structures that are at the limit of the resolution of light microscopes in natural light, visible luminescence light, in polarized light by the bright field, dark field method , phase contrast, etc.

A well-known achromatic microscope objective [1], containing three positive components, the first and second of which are plano-convex lenses, and the third component in the form of a single biconvex lens and a biconvex lens containing a negative meniscus and a biconvex lens.

The disadvantages of this lens include the residual chromaticity of magnification, astigmatism and curvature, which do not allow simultaneous observation of the entire field of view, as well as the inability to work in reflected light due to the presence of two flat surfaces, due to which the lens has a large illumination coefficient, as well as insufficient large field of view (20 mm).

The closest technical solution to the claimed invention is a planochromatic high aperture micro lens of small magnification [2].

It contains five components, the first of which is positive, made in the form of a single meniscus facing concavity to the space of objects, the second is a single positive component, the third two-parted from positive and negative lenses, the fourth single positive component, and the fifth negative, two-parted from positive and negative lenses and facing concavity to the space of images.

It has a high level of aberration correction over the entire field of view, but the front working distance is too small, and does not allow working with cuvettes in transmitted light and with manipulators in reflected light, and has an insufficiently high input aperture.

The main task to which the invention is directed is to increase the working distance to enable work with cuvettes and manipulators, as well as to increase the input numerical aperture while maintaining planochromatic correction.

The problem is solved using the proposed planochromatic high-aperture micro-lens with a large working distance, which, like the prototype, contains five components in series, the first of which is made in the form of a meniscus facing concavity to the space of objects, the second and fourth positive components, the third component is double-glued and the fifth component.

Unlike the prototype, the second positive component is made of glued from a biconvex positive lens and a negative meniscus facing concavity to the space of objects, the third two-glued component is made of a negative meniscus facing concavity to the space of images and a positive biconvex lens, and the fifth component is made of a single negative biconcave lens and two menisci facing concavity to the space of objects.

Moreover, the dispersion coefficient ν _{d of the} positive lenses of the second and third components and the meniscus located behind the biconcave negative lens in the fifth component ν _d ≥70, and the negative meniscus of the glued lens of the third and biconcave negative lens of the fifth component have a dispersion coefficient of 42≤ν _d ≤48.

The essence of the invention lies in the fact that the implementation of the second component is double-glazed, the third is glued from the negative meniscus and the positive biconvex lens, the fifth is from three single lenses, as well as the above choice of dispersion coefficients, significantly increase the working front segment (about twice) while ensuring the ability to work with cuvettes, as well as with manipulators, preserving planochromatic correction, and increase the input aperture by about 1.1 times.

Based on the foregoing, we can conclude that the new set of essential features of the claimed invention allowed us to obtain a technical result consisting in increasing the free working distance, as a result of which it is possible to work with cuvettes and manipulators, the input aperture is increased 1.1 times, while the planochromatic correction is saved, due to which the entire field of view is simultaneously observed.

The proposed planochromatic high-aperture micro lens with a large working distance is illustrated by the drawing, which shows its optical scheme, as well as the Appendix, which gives the design parameters and aberration releases.

The inventive planachromatic high-aperture micro-lens with a large working distance contains five components I, II, III, IY and Y, the first of which is a single meniscus 1, facing concavity to the space of objects, the second is two-parted from a positive biconvex lens 2 and a negative meniscus 3, facing concavity to object space, the third is double-glued from the negative meniscus 4, facing concavity to the image space, and the positive biconvex lens 5, the fourth is a single positive component ent 6, and the fifth, consisting of three single lenses 7, 8 and 9, the first of which is a biconcave lens 7, and two menisci 8 and 9, facing concavity to the space of objects.

The dispersion coefficient ν _{d of the} positive lenses 2 and 5 of the second II and third III components and the meniscus 8 located behind the biconcave negative lens 7 in the fifth component Y ν _d ≥70, and the negative meniscus 4 of the glued lens of the third III and biconcave negative lens 7 of the fifth Y component have a dispersion coefficient of 42≤ν _d ≤48.

The proposed lens works as follows.

The lens works with a tube lens f '= 160 mm.

Rays from the object of observation located in the front focal plane of the micro-lens pass through a single meniscus 1 of the first component I and a glued positive biconvex lens 2 and a negative meniscus 3 of the second component II, forming an imaginary image, introducing negative spherical aberration, to whom, positive astigmatism and curvature, further, the third component III, glued from the negative meniscus 4, turned concavity into the space of images, and a biconvex positive lens 5, forms a real image the image of the object, introducing negative spherical aberration and increase chromatism, redressing coma and astigmatism and curvature. The fourth component IY, consisting of a positive biconvex lens 6, transfers the image of the object to the front focal plane of the fifth component Y, introducing positive distortion and negative chromaticity of magnification, and then the fifth component Y, consisting of a biconcave lens 7 and two single menisci 8 and 9, facing concavity to the space of objects, transfers the image of the object to infinity, forming a plan-chromatic image of the object.

According to the proposed scheme, a micro lens with a magnification of 10 ^x , a numerical aperture of 0.38, a linear image field of 25 mm and a working distance of 4.67 mm is implemented.

Table 1 presents the Strehl number, which characterizes the image quality of the lens for the relative values of the image values.

Table 1 Rel image value Strehl number one 0.51 0.866 0.65 0.707 0.71 0.5 0.83 0 0.93

INFORMATION SOURCES

1. SU, copyright certificate No. 1580309, IPC: G02B 21/02, 1990

2. RU, copyright certificate No. 2195008, IPC: G02B 21/02, 2002 - prototype.

Claims (1)

A plano-chromatic high-aperture micro lens with a large working distance, containing five components in series, the first of which is made in the form of a meniscus facing concavity to the space of objects, the second and fourth positive components, the third component is double-glued and the fifth component, characterized in that the second positive component is made glued from a biconvex positive lens and a negative meniscus facing concavity to the space of objects, the third two the accelerated component is made of a negative meniscus facing concavity to the image space and a positive biconvex lens, and the fifth component is made of a single negative biconcave lens and two menisci facing concavity to the space of objects, with the dispersion coefficient ν _{d of the} positive lenses of the second and third components and the meniscus located behind the biconcave negative lens in the fifth component, ν _d ≥70, and the negative meniscus of the glued third lens and biconcave The fifth lens of the fifth component has a dispersion coefficient of 42≤ν _d ≤48.

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