RU127949U1 - MIRROR LENS VARIO LENS - Google Patents

Abstract

The mirror-lens zoom lens consists of two mirrors, the primary mirror being concave, facing concavity to the space of objects, with a hole in the central part, the secondary mirror is convex, facing the convex mirror surface to the image and installed with the possibility of input and output of the rays, and positive compensator, a positive component is located in front of the secondary mirror, characterized in that the said mirrors are aspherical, the shape of the mirrors is described by the equation, where z is the arrow rhnosti calculated along the optical axis of the lens; h - the current coordinate, measured along the axis perpendicular to the optical axis of the lens, expresses the height of the beam on the surface; c = 1 / r is the curvature of the surface at its vertex; r is the radius of curvature at the vertex; k is the eccentricity coefficient, the said positive compensator consists of a positive glued lens, consisting of a positive biconvex lens and a negative meniscus convex to the image, and a negative meniscus facing concavity to the object, separated by an air gap, and installed behind the primary mirror, said positive component made of glued from two components - a positive biconvex lens and a negative meniscus.

Description

The utility model relates to optical instrumentation, and more specifically, to lenses that work with CCD receivers and can be used to obtain information from external objects.

A well-known double-field lens, European patent EP 0145845, IPC G02B 17/08 published 06/26/1985, which contains 8 components. The lens has two channels: a mirror-lens optical system operating with a small field, and a lens optical system operating with a large field. Switching the optical system from narrow-field to wide-field is done by the output of the secondary mirror beyond the limits of light beams.

A disadvantage of the known lens is that the optical system cannot operate in the visible wavelength range; it has poor image quality and high design complexity.

The closest in technical solution is an infrared mirror lens with a double field of view, patent of the Russian Federation No. 2292066, IPC G02B 17/08, G02B 15/08, G02B 13/14 (2006/01), published June 15, 2005, with the following technical characteristics: narrow-field lens: focal length 180 mm, relative aperture 1: 2, angular field 2w = 7 angular degrees .; wide-field lens: focal length 74.5 mm, relative aperture 1: 2.4, angular field 2w = 17 angular degrees.

This lens is chosen by the authors for the prototype. The infrared mirror lens with a double field of view includes a lens compensator made in the form of a positive meniscus, convex to the object with an aperture in the central part, a concave primary Manzhen mirror, made in the form of a negative meniscus, convex to the image, on the convex surface of which is applied mirror coating with a hole in the central part, a secondary counter-mirror, with a mirror coating on a convex surface, convex to the image and installed Focal compensator made with the possibility of input and output from the ray path, made in the form of a positive meniscus convex to the object and installed in the hole of the primary Mangin mirror. In front of the lens compensator, the positive meniscus, there is a negative meniscus facing concavity to the object, and behind it, in front of the counter-mirror, there is a biconvex lens in the central opening of the lens compensator, the positive meniscus.

The disadvantage of the prototype is the lack of ability to work in the visible range of the spectrum, the small focal length of a narrow-field lens, a small difference in magnification when moving from a narrow-field lens to a wide-field lens.

The objective of the utility model is to ensure the operation of the lens in the visible wavelength range with two different magnifications, while the output of the secondary mirror from the path of the rays, the lens should work with an increased angular field.

The solution to this problem is achieved by the fact that in the mirror-lens zoom lens, consisting of two mirrors, the primary mirror is concave, facing concavity to the space of objects, with a hole in the central part, the secondary mirror is convex, facing the convex mirror surface to the image and installed with the possibility of input and its withdrawal from the path of the rays, and the positive compensator, in front of the secondary mirror is the positive component, the mentioned mirrors (first and second mirrors) are aspherical, shape Mirrors are described by the equation:

,

,

where z is the arrow of the surface, calculated along the optical axis of the lens, h is the current coordinate, measured along the axis perpendicular to the optical axis of the lens, expresses the height of the beam on the surface; c = 1 / r is the curvature of the surface at its vertex; r is the radius of curvature at the vertex; k is the coefficient of eccentricity; said positive compensator consists of a positive glued lens, consisting of a positive biconvex lens and a negative meniscus convex to the image, and a negative meniscus facing concavity to the object, separated by an air gap, and mounted behind the primary mirror; the common positive component is glued from two components, a positive biconvex lens and a negative meniscus.

The installation of the second component with the ability to input and output from the path of the rays makes it possible to operate the system with two different magnifications, and a lens working with a lower magnification works with an increased angular field. The implementation of the reflective surfaces of the first and second mirrors with aspherical surfaces provides aplanatic correction of aberrations in the lens, working with high magnification.

The implementation of a positive compensator of a positive glued lens and a negative meniscus, separated by an air gap, makes it possible to correct astigmatism. The implementation of the positive component located in front of the secondary mirror, in the form of a glued component of two lenses made of different brands of glass, as well as the implementation of the positive compensator of the glued positive lens, consisting of a positive biconvex lens and a negative meniscus, and a negative meniscus made of different brands glasses allows the system to operate in the visible wavelength range.

The specified combination provides the necessary and sufficient number of parameters of the optical system that allows you to create a zoom lens that operates in the visible wavelength range with two different magnifications, while working with a lower magnification, the lens works with an increased angular field, which is achieved due to the structural design of the optical circuit of the lens.

The combination of all the features allows us to solve the problem, the exclusion of any of them leads to the inability to implement a mirror-lens lens with the ability to change the magnification and the increased field of the lens.

The invention is illustrated by drawings: where in Fig.1 a, b two optical schemes of a mirror-lens lens are presented, a is a system with a secondary mirror, b is a system after the secondary mirror is removed from the path of the rays;

figure 2 a, b presents graphs of frequency-contrast characteristics for two optical lens circuits according to the invention, a - a secondary mirror is installed during the rays, b - the secondary mirror is removed from the rays.

The mirror-lens zoom lens contains five components sequentially located along the beam, the first component 1 is a concave mirror, the second 2 is a convex mirror, the third component 3 is a positive glued lens, the fourth component is a single negative meniscus facing concavity to the space of objects 4, fifth component - positive component 5 installed in front of the secondary mirror.

The lens works as follows:

1. The luminous flux from an infinitely distant object sequentially passes through all the lens elements, in the case a, when the secondary mirror is installed during the rays, 1-4, the image is formed in the focal plane 6 of the lens. The image is then combined with the photosensitive layer of the CCD matrix (not shown in the drawings).

2. In order to change the magnification, a convex mirror is replaced by a positive lens component, the light flux from an infinitely distant object passes through the lens elements 5, 3, 4, after which an image is formed in the focal plane 6 of the lens. The image is then combined with the photosensitive layer of the CCD matrix (not shown in the drawings).

An example of a specific implementation of the invention is a mirror-lens zoom lens, focal length of a narrow-field lens 1000 mm, focal length of a wide-field lens 333.3 mm, relative aperture 1: 5 angular fields 2w = 2 ° and 10 °, respectively, full linear fields in the image space - 17.5 mm and 29.1 mm.

The design parameters for the two configurations of the mirror-lens zoom lens are presented in tables 1.1 and 1.2, the technical characteristics of the lens as a whole are given in table 2.

Table 1.1. The design parameters of the lens with high magnification and a small angular field. N surface Radii, mm Thickness mm Glass brands Light diameters, mm Aspheric Ratio An object infinity - 1 - aperture -712.62 -240 Mirror 200.25 1.154801 2 -359.16 251.41 Mirror 74.46 6.024484 3 233.23 fifteen N-bak1 44.22 four -110.8 4.17 - 42.49 5 -118.17 4.34 SSKN8 40.38 6 4152.62 twenty - 39.48 7 -72.76 10.9 P-SK57 35.34 8 -237.36 26.55 35.84 Picture 35.19

Table 1.2. The design parameters of the lens with an enlarged field and a smaller increase. N surface Radii, mm Thickness mm Glass brands Light diameters, mm An object infinity - 1 - aperture 205.95 fifteen N-PSK58 66.47 2 -112.98 8 KZFS1 66.42 3 -1005.68 245 66.52 four 233.23 fifteen N-bak1 59.96 5 -110.8 4.17 - 58.95 6 -118.17 4.34 SSKN8 56.48 7 4152.62 twenty - 55.56 8 -72.76 10.9 P-SK57 52.88 9 -237.36 26.55 55.36 Picture 59.31 Table 2. Lens specifications. N Feature Name Value one Focal length mm 333.3 2 Angular field, angle 10 3 Relative hole 1: 5 four Rear focal length, mm 26.55 5 Total length mm 348.97 N Feature Name Value one Focal length mm 1000 2 Angular field, angle 2 3 Relative hole 1: 5 four Rear focal length, mm 26.55 5 Total length mm 332.37

The technical advantage of the invention in comparison with the prototype is the ability to work in the visible wavelength range.

Realization of the technical advantages of the lens according to the proposed utility model increases its information content, which allows it to be used as a mirror-lens lens with variable magnification and allowing to search for an object with an increased field in the visible wavelength range.

Claims (1)

The mirror-lens zoom lens consists of two mirrors, the primary mirror being concave, facing concavity to the space of objects, with an aperture in the central part, the secondary mirror is convex, facing the image with a convex mirror surface, and installed with the possibility of input and output from the rays, and positive compensator, in front of the secondary mirror there is a positive component, characterized in that the said mirrors are aspherical, the shape of the mirrors is described by the equation

, where z is the surface arrow calculated along the optical axis of the lens; h is the current coordinate, measured along the axis perpendicular to the optical axis of the lens, expresses the height of the beam on the surface; c = 1 / r is the curvature of the surface at its apex; r is the radius of curvature at the vertex; k is the eccentricity coefficient, the said positive compensator consists of a positive glued lens, consisting of a positive biconvex lens and a negative meniscus convex to the image, and a negative meniscus facing concavity to the object, separated by an air gap, and installed behind the primary mirror, said positive component made of glued from two components - a positive biconvex lens and a negative meniscus.

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