RU2008710C1 - Mirror-lens objective for microscope - Google Patents

Abstract

FIELD: optical instrument technology. SUBSTANCE: mirror-lens objective has mirror-lens member with first concave spheroidal surface and two spherical concentric reflecting surfaces concave with respect to object direction. There is fourth refracting surface made convex and fixed and placed at distance not more then 5,5 F with respect to second reflecting surface. F is focal length of objective. Behind mirror-lens member positive meniscus is placed along optical axis with concavity directed to image, then there are biconcave lens, negative meniscus with concavity directed to object, which can be made like together bond of biconcave and biconvex lenses, finally there is negative meniscus which concavity is directed to image and it is perhaps made like together bond of biconvex and biconcave lenses. EFFECT: more effective objective construction. 2 cl, 4 dwg

Description

 The invention relates to optical instrumentation, namely to mirror-lens microscope lenses.

 Known mirror lens microscope with a magnification of 40x0.65, described in [1]. The front of the lens consists of two aplanatic menisci transmitting an image of the object in a scale of 225 *, which allows you to calculate the lens with the minimum allowable transverse dimensions. To compensate for the chromaticity of the position given by aplanatic menisci, the concave mirror is made of OF3 glass and has internal silvering. The largest wave aberration is 0.06 λ, the secondary spectrum is practically absent. As a prototype, the mirror-lens microscope objective described in [2] with a magnification of 60 x 0.85 was chosen. The object is located in the center of curvature of surface 1, surface 2 is aluminized and slightly retouched.

 The rays reflected from the aluminized concentric surfaces 2 and 3 meet the surface 4 without experiencing refraction on it.

 But this lens has not good enough image quality, a small front working segment.

 The aim of the invention is to increase the scale and improve image quality, increase the working length.

The essence of the invention lies in the fact that the mirror-lens microscope containing a mirror-lens component with a first concave spherical refractive surface, two reflective concentric surfaces facing concavity to the object, and a fourth refractive surface, the fourth refractive surface is convex and located at a distance not more than _about 5,5 f ¹ from the second reflective surface, and for the mirror-lens component introduced positive meniscus facing the concavity to Images Agen, biconcave lens and two negative meniscus, the first of which is concave to the object, and the second - to the image, wherein the thickness of the second meniscus at least _about 4.5 f ^1, where f ^{_v, 1} - lens focal distance.

 Mirror-lens lens - the first negative meniscus is made of glued from biconcave and biconvex lenses, and the second from biconvex and biconcave lenses.

The fourth refracting surface of the mirror-lens component is convex and located at a distance of not more than 5.5 f _about ¹ from the second reflecting surface to correct spherical aberration for a point on the axis, for wide inclined beams of rays, coma.

 Behind the mirror-lens component, a positive meniscus with concavity towards the image, a biconcave lens, and two negative meniscuses are introduced, the first of which faces the object with the concavity, and the second towards the image. All the lenses located behind the mirror-lens component are a compensator that provides correction of coma, image curvature and astigmatism, chromatic aberration - position chromatism, chromatism of increasing their spherochromatism.

The thickness of the second negative meniscus is not less than 4.5 f _rev ¹ , where f _rev ¹ is the focal length of the lens, provides correction of image curvature and astigmatism.

 The developed lens design provides a large front working segment, which in a specific example is 17.8 mm.

 In the mirror-lens lens according to claim 2, to increase the front working segment (up to 20.8 mm), the first negative meniscus is made of glued biconcave and biconvex lenses, and the second of biconvex and biconcave lenses.

 In FIG. 1 is an optical diagram of a specular-lens microscope objective with structural data according to claim 1, wherein 1 is a specular-lens component having two refracting surfaces 2 and 3 and two reflecting surfaces 4 and 5, 6 — a positive meniscus facing a concavity to the image , 7 - a biconcave lens, 8 - the first negative meniscus facing concavity to the subject, 9 - the second negative meniscus facing concavity to the image.

 In FIG. 2 presents graphs of its aberrations.

 In FIG. 3 shows the optical scheme of the mirror lens according to claim 2, where 10 and 11 are the biconcave and biconvex lenses of the first glued negative meniscus 8, respectively, and 12 and 13 are the biconvex and biconcave lenses of the second glued negative meniscus 9, respectively.

 In FIG. 4 presents graphs of its aberrations.

As a specific example, a mirror-lens lens with the following optical characteristics is calculated: Focal length 2.5 mm, Object size 0.34 mm, Working distance 17.8 mm, Aperture 0.9
The specified mirror lens has the following aberrations.

Transverse spherical aberration for the main wavelength for a point on the axis is: pupil edge 0.012 mm area 0.0003 mm
The pupil wave aberration for the main wavelength does not exceed 0.17 λ. Neusoplanasia coefficient: pupil margin - 0.23%, zone - 0.21%. Image curvature and astigmatism are equal: y = -0.17 z _t ¹ = -0.001 mm z _s ¹ = -0.0008 mm y = -0.12 z _t ¹ = -0.0006 mm z _s ¹ = -0, 0004 mm
The chromaticity of magnification over the entire field does not exceed 0.03, which is a small value for lenses of such magnification.

As a second specific example, a mirror-lens microscope with the following optical characteristics is calculated: Focal length 12.5 mm Object size 0.34 mm Working distance 20.8 mm Aperture 0.9
This mirror lens has the following aberrations. Transverse spherical aberration for the main wavelength for a point on the axis is: pupil edge 0.0007 mm area 0.0001 mm
The pupil wave aberration for the main wavelength does not exceed 0.12 λ. Image curvature and astigmatism are equal: y = -0.17 z _t ¹ = -0.0009 mm z _s ¹ = -0.0009 mm y = -0.12 z _t ¹ = -0.0006 mm z _s ¹ = - 0,0005 mm
A beam of rays coming from an object located in the front focal plane of the lens, within the lens aperture, sequentially passes components 1, 6, 7, 8, 9 and creates an image at infinity. (56) V.A. Popov and L.N. Andreev. Optics of microscopes. L.: Engineering, 1976, p. 216-218.

 Skvortsov G.E. et al. Microscopes. L.: Mechanical Engineering, 1969, p. 217-218.

Claims (2)

1. MIRROR-LENS LENS MICROSCOPE containing a zoom lens component with a first concave spherical refracting surface, two reflective concentric surfaces facing concavity to the object, and a fourth refracting surface, characterized in that, in order to increase the scale and improve image quality, the fourth refracting surface made convex and located at a distance of not more than 5.5 f $\genfrac{}{}{0ex}{}{\text{′}}{\text{about}}$ _b from the second reflecting surface, and behind the mirror-lens component, a positive meniscus with a concavity towards the image, a biconcave lens and two negative meniscuses are introduced, the first of which faces the object with concavity and the second to the image, while the thickness of the second meniscus is at least 4 , 5 f $\genfrac{}{}{0ex}{}{\text{′}}{\text{about}}$ _b , where f $\genfrac{}{}{0ex}{}{\text{′}}{\text{about}}$ _b - the focal length of the lens.  2. The lens according to claim 1, characterized in that, in order to increase the working length, the first negative meniscus is made of glued from biconcave and biconvex lenses, and the second from biconvex and biconcave lenses.

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