RU182711U1 - OPTICAL SYSTEM OF OPTICAL ELECTRONIC COORDINATOR - Google Patents

Abstract

The utility model relates to the field of optical instrumentation. The optical system of the optoelectronic coordinator comprises a sequentially mounted radome, a lens containing the main and secondary mirrors, a projection system consisting of an eyepiece and a condenser, and a radiation receiver. Behind the secondary mirror, a spectro-splitting filter is installed that transmits the radiation of the spectral range Δλ and reflects the radiation of the spectral range Δλ, and a photodetector installed in the central hole of the secondary mirror. The projection system is installed behind the spectrodividing filter in the transmission radiation of the spectral range Δλ, is made with a negative increase in β, satisfying the condition 1 <β <1.3, and is a five-lens design, of which the first and fifth lenses are made in the form of positive menisci, convex to each other to a friend, the second, third and fourth lenses form a triplet with a third biconcave lens and second and fourth positive menisci facing each other. The optical power of the lenses satisfy the condition: 1 <ϕ / ϕ <1.3; 1 <ϕ / ϕ <1.3, where ϕ, ϕ are the optical powers of the first and fifth lenses, respectively, ϕ, ϕ are the optical powers of the triplet and the entire projection system as a whole, respectively. The primary and secondary mirrors are aspherical, the radii of curvature at the vertices of which R and R satisfy the condition: | R / R | <0.15 ÷ 0.2, between which there is a positive compensation meniscus convex to the main mirror. The technical result is the provision of work in two spectral ranges, an increase in aperture ratio at large pumping angles and small dimensions. 1 ill.

Description

The proposed utility model relates to the field of optical instrumentation and can be used for homing heads (GOS) in optoelectronic coordinators, in devices designed for the detection and subsequent tracking of objects, in particular, as part of on-board equipment operating in one or more spectral ranges .

A number of special requirements are imposed on GOS optical systems:

1. High aperture of the optical system (OS).

To register objects of finite sizes, whose images in the plane of the matrix receivers exceed the dimensions of the receiver elements (e.g., a pixel), the aperture ratio is proportional to the square of the relative aperture (D / f ') ² , where D is the diameter of the entrance pupil, f' is the focal length of the OS. For point objects whose image sizes fit in the pixel size, the aperture ratio is proportional to D ² . Therefore, for GOS working on small and large objects, the OS should have large diameters (D) and small focal lengths f '.

2. The presence of a spherical concentric protective glass and ensuring OS pumping within ± 20 °.

3. Small overall mass characteristics.

4. High image quality: the value of the energy concentration in the pixel is not less than 80% in the center of the field.

5. The presence of an intermediate image of the OS object for the installation of protective filters, image analyzers, etc.

A well-known optical system OEC GSN [1], consisting of a fairing arranged in the form of a convex-concave lens, a main mirror with a central hole, a second mirror with a dividing spectrum with a dividing surface, divided by radiation into two spectral ranges Δλ ₁ and Δλ _2, two lens aberrations compensators, one of which is mounted a secondary mirror reflected from Δλ ₁ radiation transmitted through the second surface radiation spektrodelitelnuyu Δλ ₂ and two radiation detectors cn ktralnyh ranges.

The disadvantage of the OEC optical system is the lack of an intermediate image of the object.

The closest technical solution to the proposed utility model is the OEC optical system [2], containing a sequentially mounted fairing, a lens containing the main (GB) and secondary (BZ) mirrors, a projection system consisting of an eyepiece and a condenser and a radiation receiver.

The disadvantages of the OS OEC taken as a prototype are:

- registration of the image of the object in only one spectral range Δλ ₂ ;

- large dimensions and mass due to the fact that the intermediate image is located behind the GB, and the design of the projection system consists of two components: an eyepiece and a condenser;

- reduced aperture, limited by the use of two component projection system;

- the difficulty of implementing large pumping angles.

The main task, which the utility model is aimed at, is to expand the functionality of the OEC operating system by providing operation in two spectral ranges, a large aperture ratio at large pumping angles and small dimensions.

To solve this problem, an optical system of an optoelectronic coordinator is proposed, which, like the prototype, contains a sequentially mounted fairing, a lens containing the main and secondary mirrors, a projection system consisting of an eyepiece and a condenser, and a radiation receiver.

In contrast to the prototype, the proposed optical system of the optoelectronic coordinator behind the secondary mirror has a spectro-splitting filter that transmits spectral radiation Δλ ₁ and reflects spectral radiation Δλ ₂ and a photodetector installed in the central hole of the secondary mirror, the projection system is installed behind the spectro-splitter filter radiation of the spectral range Δλ ₁ and performed with a negative increase in β, satisfying the condition 1 <β <1.3, and represents a five-lens design, of which the first and fifth lenses are made in the form of positive meniscuses convex to each other, the second, third and fourth lenses form a triplet with a third biconcave lens and second and fourth positive menisci facing each other, while the optical forces lenses satisfy the condition: 1 <ϕ ₁ / ϕ ₅ <1.3; 1 <ϕ _{2 ÷ 4} / ϕ <1.3, where ϕ ₁ , ϕ ₅ are the optical powers of the first and fifth lenses, respectively, ϕ _{2 ÷ 4} , ϕ are the optical powers of the triplet and the entire projection system as a whole, respectively, in addition, the main thing and the secondary mirror is aspherical, the radii of curvature at the vertices of which R _GB and R _BZ satisfy the condition:

| R _HR / R _OT | <0.15 ÷ 0.2, between which a positive compensation meniscus is installed, convex to the main mirror.

The essence of the proposed optical system of the optoelectronic coordinator is as follows.

где D - диаметр ГЗ входного зрачка оптической силы, f'-фокусное расстояние зеркально-линзовой системы, исправить сферическую аберрацию, кому и астигматизм.The execution of GB and VZ with concave aspherical shape with a radius of curvature at the vertices of the surfaces R _GB and R _VZ satisfy the condition: | R _GB / R _ВЗ | <0.15 ÷ 0.2 and setting a compensation positive meniscus between them, convex to GB, allowed over large relative holes

where D is the GB diameter of the entrance pupil of optical power, the f'-focal length of the mirror-lens system, correct spherical aberration, coma and astigmatism.

где

- половина линейного поля в плоскости изображения, А' - задняя апертура, в данной оптической системе весьма значительное и составляет при

А'=0,86, М=2,4 мм. Для сравнения, например, в классических высокоапертурных линзовых объективах микроскопов М≅0,1÷0,12 мм.Lagrange Number

Where

- half of the linear field in the image plane, A 'is the rear aperture, in this optical system is very significant and is at

A '= 0.86, M = 2.4 mm. For comparison, for example, in classical high-aperture lenses of microscopes М≅0.1 ÷ 0.12 mm.

In addition, this design of the mirror-lens component, which includes the GB, a compensation lens, and the VZ, allows one to obtain a back segment — the distance from the VZ to the focal plane of the mirror-lens optical component is sufficient to install a plane-parallel plate with a spectro-splitting coating on the surface that divides the radiation into ranges Δλ ₁ and Δλ ₂ .

The projection system, working with a negative increase in β, satisfying the condition 1 <β <1.3, provides a partial correction of field aberrations: coma, distortion, transverse chromatism.

The first and fifth lenses are positive menisci, close to aplanatic, with optical forces satisfying the condition: 1 <ϕ ₁ / ϕ ₅ <1.3, provide the triplet formed by the second, third and fourth lenses, working from a finite to a finite distance with negative magnification and with an optical power ϕ _{2 ÷ 4} satisfying the condition: 1 <ϕ _{2 ÷ 4} / ϕ <1,3, ϕ is the optical power of the entire projection lens with small input and output apertures and with compensated spherical aberration, astigmatism, coma and curvature of the image.

The essence of the proposed utility model is illustrated by the drawing, where in FIG. 1 - presents the optical scheme of the OEC.

The proposed optical system of the optoelectronic coordinator comprises a fairing 1, a concave main mirror 2 and a secondary mirror 3 made aspherical, the radii of curvature at the vertices of which R _GB and R _BZ satisfy the condition: | R _GB / R _BZ | <0.15 ÷ 0, 2, projection system 4, radiation receiver 5.

Behind VZ 3, in the gap in front of the equivalent focus F ' _0, a spectro-splitting filter 6 is installed, which transmits radiation Δλ ₂ and the photodetector 7 is installed in the central hole of VZ 3.

The projection system 4 is a compact symmetrical micro-lens made of five high-aperture lenses with an aperture diaphragm image.

The first lens 8 of the projection system 4 is made in the form of a positive meniscus convex to the image plane F ' ₂ , the second lens 9 is a positive meniscus facing concavity to the image plane F' ₂ , the third lens 10 is biconcave, the fourth lens 11 is a positive meniscus, facing the image plane F ' ₂ , the fifth lens 12 is a positive meniscus facing concavity to the image plane F' ₁ .

The first 8 and fifth 12 lenses are convex to each other, and the second 9, third 10 and fourth 11 lenses form a triplet.

Between GB 2 and VZ 3 there is a compensation meniscus 13 convex to GB 2. Together with fairing 1, they form a mirror-lens component with an equivalent focus F ' ₀ .

The optical system of the optical-electronic coordinator is as follows.

A registered object located at infinity emits radiation with a parallel path of rays, which, after passing through the fairing 1, is reflected from the GB 2, passes through the compensation lens 13, and after reflection from the VZ 3 it is divided by a spectro-splitting filter 6 into two ranges: infrared (IR) and photo-contrast ( FC).

In the focal planes of the mirror-lens component, images of the object are formed: in the plane F ' ₀ - the image given by the radiation Δλ ₁ , in the plane F' ₂ - the image given by the radiation Δλ ₂ .

In the channel, radiation Δλ _{1, the} image F ' _{0 is} transferred by the projection system 4 to the plane F' ₂ , where a receiver 5 is installed to register the image of the object with radiation Δλ ₁ .

As an example, the optical system of the optoelectronic coordinator with the following characteristics is given.

The channel of the spectral range Δλ ₁ includes: a fairing 1, a concave main mirror 2, a compensation meniscus 13, a secondary mirror 3, a spectrodividing filter 6, a projection system 4 (The first lens 8, made in the form of a positive meniscus convex to the image plane F ' ₂ , the second lens 9 is the positive meniscus facing concavity to the image plane F ' ₂ , the third lens 10 is biconcave, the fourth lens 11 is the positive meniscus facing the image plane F' ₂ , the fifth lens 12 is the positive meniscus facing th concavity to the image plane F ' ₁ ), radiation receiver 5.

spectral range Δλ ₁ = IR range;

focal length, mm F '= 46.98 mm

the diameter of the entrance pupil is 50.6;

the diameter of the aperture diaphragm - the light diameter of the main mirror 2 - 50.6;

angular field, degrees - 2 β = 3.3 °;

magnification of the projection system 4 - β = -1.29 ^x ;

projection system 4:

optical power ϕ = 0.104;

the ratio of the optical powers of the triplet (lenses 9, 10, and 11) to the optical power of the lens ϕ _{2 ÷ 4} / ϕ = 1.174;

the ratio of the optical forces of the first and fifth lenses ϕ ₁ / ϕ ₅ = ϕ ₈ / ϕ ₁₂ = 1,156;

the ratio of the radii of curvature at the vertices of the main mirror 2

R ₂ = R _GB to the radius at the apex of the secondary mirror R _B3 = R ₃

R _GB / R _B3 = R ₂ / R ₃ = 0.176;

The main mirror 2 is a higher-order hyperboloid of rotation with an eccentricity e ² = 1.507543;

The secondary mirror 3 is a higher-order paraboloid of revolution with an eccentricity e ² = + 1.

The channel of the spectral range Δλ ₂ includes: a cowl 1, a concave main mirror 2, a compensation meniscus 13, a secondary mirror 3, a spectro-split filter 6, a photodetector 7.

spectral range Δλ ₂ = FC range;

the diameter of the entrance pupil is 50, 6;

the diameter of the aperture diaphragm - the light diameter of the main mirror 2 - 50.6;

angular field, degrees - 2 β = 4.6 °.

Quality OS OEC:

1. Channel Δλ ₁ = IR range

The concentration of energy in a pixel with a diameter of 160 microns

in the center of the field E = 0.68%

at the edge of the field E = 0.78%

2. Channel Δλ ₂ = FC range

The concentration of energy in a pixel with a diameter of 40 microns

in the center of the field E = 0.88%

on the edge of the field E = 0.90%

The advantages of the proposed OS OEC include the expansion of functionality by ensuring operation in two spectral ranges Δλ ₁ = IR and Δλ ₂ = FC, which significantly increases the probability of target detection and tracking; the presence of an intermediate image that allows you to install special protective, anti-laser filters, masks and other elements that increase the reliability and efficiency of the OS OEC; large aperture at small dimensions, increasing the detection range of the target, etc.

INFORMATION SOURCES

1. Russian Federation, patent for utility model No. 171187, IPC: G02B 17/08, G02B 23/04, publ. 05/23/2017

2. Russian Federation, patent for invention No. 2140659, IPC: G01S 7/483, publ. October 27, 1999 - a prototype.

Claims (1)

The optical system of the optoelectronic coordinator, comprising a sequentially mounted fairing, a lens containing the main and secondary mirrors, a projection system consisting of an eyepiece and a condenser, a radiation receiver, characterized in that a spectro-splitting filter is installed behind the secondary mirror, transmitting radiation of the spectral range Δλ ₁ and reflecting the radiation spectral band Δλ ₂ and a photodetector mounted in the central opening of the secondary mirror projection system is set for spectrum odelitelnym filter transmits radiation in a spectral band Δλ ₁ and is provided with a negative increase in β, satisfies the condition 1 <β <1,3, and represents pyatilinzovuyu structure from which the first and fifth lens are formed as positive meniscus, convexities facing each other, the second, third and fourth lenses form a triplet with a third biconcave lens and the second and fourth positive menisci facing each other, while the optical forces of the lenses satisfy the condition: 1 <ϕ ₁ / ϕ ₅ <l, 3; 1 <ϕ _{2 ÷ 4} / ϕ <1.3, where ϕ ₁ , ϕ ₅ are the optical powers of the first and fifth lenses, respectively, ϕ _{2 ÷ 4} , ϕ are the optical powers of the triplet and the entire projection system as a whole, respectively, in addition, the main thing and the secondary mirror is aspherical, the radii of curvature at the vertices of which R _GB and R _ВЗ satisfy the condition: | R _ГЗ / R _ВЗ | <0.15 ÷ 0.2, between which there is a positive compensation meniscus convex to the main mirror.

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