RU193694U1 - PLANOCHROMATIC MICRO LENS - Google Patents

Abstract

A micro lens contains three components. The first component I with optical power ϕ is made in the form of a meniscus turned concavity into the space of the object, and a positive meniscus turned concavity into the space of the object. The second component II with an optical power ϕ consists of a biconvex lens glued together with a negative meniscus, turned concave into the object space, and a biconvex lens. The third component III with optical power ϕ contains a glued meniscus, in front of which along the beam there is a lens glued from a negative and biconvex lens, and a positive meniscus turned concavity into the image space, and the glued meniscus contains a negative and positive meniscus turned concavity into the space of the object. The relations are satisfied: 0.25≤ϕ / ϕ≤1.2, 0.15≤ϕ / ϕ≤0.9, -0.95≤ϕ≤-0.12, where ϕ is the optical power of the lens as a whole. The technical result is an increase in the working distance to use a variable thickness of the coverslip and achieve planochromatic correction to ensure high resolution. 1 s.p. f-ly, 4 ill.

Description

The proposed utility model relates to the field of microscopy 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.

Modern models of microscopes require a planochromatic micro-lenses to be equipped with the ability to observe cultured cells when using dishes to place the objects under study with large thickness differences (hereinafter - coverslip), which cause a significant change in aberrations, as well as a large working distance that allows manipulation with the studied object . Such a micro lens should be able to correct the arising aberrations.

A planochromatic microscope objective is known [1], which contains four components, the first of which has a positive force and contains three meniscus convex to the image, the second has a positive force containing a glued lens of negative and positive lenses and a single biconvex lens, the third glued component, contains a positive biconvex and negative biconcave lenses, the fourth component is a glued lens consisting of negative and positive menisci facing klostyu to the image.

The second component has the ability to move along the optical axis between the first and third components to compensate for the aberrations that occur when the thickness of the cover glass changes.

The lens has a large aperture (0.7), the ability to work with a variable thickness of the coverslip, high image quality over the entire linear field of view (2y '= 22 mm), but its working distance (~ 1.7 mm) does not allow manipulation with the studied object.

The closest technical solution to the proposed invention is a planachromatic high-aperture micro lens [2], which contains three components, the first of which is made in the form of a frontal meniscus facing concavity to the object’s space and a biconvex positive lens, and the second contains a bonded lens made of biconvex positive and a biconcave negative lens, a biconvex positive lens and a glued lens from a negative meniscus and a biconvex lens, and the third component in Full glued of the positive and negative meniscus facing concavity in the object space.

The micro lens has a high input aperture (20 × 0.7), planochromatic correction, but its working distance is small (no more than 1 mm) and it works with a constant thickness of the coverslip.

The main task to which the proposed utility model is directed is to increase the working distance for using a variable thickness of the coverslip when placing the objects under study and to achieve planochromatic correction to ensure high resolution when observing objects.

To solve this problem, we proposed a planochromatic micro lens, which, like the prototype, contains three components, the first of which I with the optical power ϕ _{I is} made in the form of a meniscus facing concavity into the space of the object and a positive lens, the second component II with the optical power ϕ _II , consisting of a bonded positive biconvex and negative lens and a positive biconvex lens, and a third component III with optical power ϕ _III , containing a glued meniscus.

Unlike the prototype, in the first component the positive lens is made in the form of a meniscus turned concave into the space of the object, in the second component the negative lens in the glued lens is made in the form of a meniscus turned concavity into the space of the object, and the third component is placed in front of the glued meniscus along the beam a glued lens consisting of negative and positive biconvex lenses, and a positive meniscus turned concavity into the image space, and the glued meniscus contains a negative and positive menisci facing concavity into the space of the object, while the ratio of the optical forces of the components and the lens as a whole ϕ _ob satisfy the following conditions: 0.25≤ϕ _I / ϕ _rev ≤1.2, 0.15≤ϕ _II / ϕ _rev ≤0.9, -0.95≤ϕ _III ≤-0.12.

In addition, the third component is capable of moving along the optical axis by a value from 0.1f 'to 0.4f' to compensate for aberrations that occur when the thickness of the cover glass changes, where f 'is the focal length of the micro-lens.

The essence of the proposed utility model is that, such a micro lens made it possible to obtain a large working distance (0.65-0.8) f 'with a variable thickness of the coverslip, while the plan-chromatic correction was achieved.

Thus, a technical result has been achieved, consisting in increasing the working distance, achieving plan-chromatic correction with a variable thickness of the cover glass.

The proposed utility model is illustrated by drawings, where in FIG. 1 - an optical diagram of a planochromatic micro-lens is presented; in FIG. 2 - Frequency-Contrast Characteristic at a thickness of 1 mm; FIG. 3 - Frequency-Contrast Characteristic with a thickness of cover glass 0.001 mm; FIG. 4 - Frequency-Contrast Characteristic at a thickness of 2 mm on the cover glass.

The plan-chromatic micro-lens contains three components, the first of which I with the optical power ϕ _{I is} made in the form of a negative meniscus 1 and a positive meniscus 2 facing concavity into the object space, while the ratio of the optical forces of the component I ϕ _I and the entire lens ϕ is _about 0.25≤ϕ _I / ϕ _rev ≤1.2, the second component II with optical power ϕ _II , consists of a glued positive biconvex lens 3 and a negative meniscus 4 turned concavity into the space of the object, and a single positive biconvex lens 5, while the ratio of optical forces 0.15≤ϕ _II / ϕ _about ≤0.9.

The third component with optical power ϕ _III contains a negative bonded lens of biconcave negative 6 and biconvex positive 7 lenses, positive meniscus 8 facing concavity to the image space, and positive 9 and negative 10 menisci facing concavity to the space of the object, while the ratio of optical forces -0.95≤ϕ _III ≤-0.12.

In addition, the third component is capable of moving along the optical axis by a value from 0.1f 'to 0.4f' to compensate for aberrations that occur when the thickness of the cover glass changes, where f 'is the focal length of the micro-lens.

The proposed planochromatic micro lens works as follows.

The micro lens works with a tube lens with a focus of 200 mm.

The front meniscus 1, facing concavity to the space of the object, together with the biconvex lens 2, builds an enlarged imaginary image of the object with moderate values of spherical aberration, coma, astigmatism and curvature and significant chromaticity of magnification (HR).

The second component II projects the image of the object with an additional increase in the focal plane of the third component III, introducing negative spherical aberration, positive coma and astigmatism, partially compensating for the chromaticity of the position and magnification.

Component III projects the image of the object to infinity, compensating for residual spherical aberration, chromaticity of position and magnification, astigmatism and curvature.

In accordance with the proposed technical solution, as a specific example, a planochromatic micro-lens was calculated with a magnification of 20 times, an input aperture of 0.45, a linear image field of 22 mm, while the thickness of the cover glass varies from 0 to 0.2f ' _rev , and the working distance from the coverslip to the surface of the first lens, from 0.65f ' _rev to 0.8f' _rev

The lens has high image quality over the entire linear field of view 2y = 22 mm.

Thus, over the entire linear field of view of the lens, the Strehl ratio is from 0.98 in the center to 0.8 at the field edge with a cover glass thickness of 1 mm, 0.95 in the center up to 0.52 at the field edge with a cover glass thickness of 0.001 mm and 0.9 in center to 0.66 at the edge of the field with a cover glass thickness of 2 mm.

Such large values cause a high concentration of energy in the center of the diffraction spot, and, consequently, a high image contrast over the entire field of observation.

Chromatic difference of magnifications in the lens of HRU ≤0.4%.

The calculation results are given in the appendix.

application

Focal length, mm: 10.085

Numerical aperture in the space of objects NA: 0.45

The size of the subject 2Y, mm: 1.100

The distance from the first surface to the square. fig., mm: 59.94

Thus, an increase in the working distance was achieved for using a variable thickness of the coverslip when placing the objects under study and planochromatic correction was achieved to ensure high resolution when observing objects.

INFORMATION SOURCES

1. United States, patent for the invention No. 201322920, IPC G02B 21/02, 2013

2. Russian Federation, patent for utility model No. 116250, IPC: G02B 21/02, 2012 - prototype.

Claims (3)

1. Plano-chromatic micro-lens containing three components, the first of which I with the optical power ϕ _{I is} made in the form of a meniscus, turned concavity into the space of the object, and a positive lens, the second component II with the optical power ϕ _II , consisting of glued from a positive biconvex and negative lenses and a positive biconvex lens, and the third component III with optical power ϕ _III , containing a glued meniscus, characterized in that in the first component the positive lens is made in the form of a meniscus facing concave остью into the object’s space, in the second component the negative lens in the glued lens is made in the form of a meniscus facing concavity into the object’s space, and in the third component, in front of the glued meniscus, a glued lens consisting of a negative and positive biconvex lens and a positive meniscus are placed facing concavity into the space of the image, and the glued meniscus contains negative and positive menisci turned concavity into the space of the object, while the ratio of optical and lens components in the whole _of φ satisfy the following conditions: 0.25≤ϕ _I / ϕ _rev ≤1.2, 0.15≤ϕ _II / ϕ _rev ≤0.9, -0.95≤ϕ _III ≤-0.12. 2. Plano-chromatic micro lens according to claim 1, characterized in that the third component is arranged to move along the optical axis by a value from 0.1f 'to 0.4f' to compensate for aberrations arising from a change in the thickness of the coverslip, where f 'is the focal length of the micro lens .

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