RU2365954C1 - Telescopic optical system (versions) - Google Patents

Abstract

FIELD: instrument engineering.

SUBSTANCE: system can be used for operation in beam forward trace and flyback, e.g. as an afocal attachment for variable-magnification visualising instruments and in laser systems. The system comprises a first component that represents an einzel negative lens, and a second component consisting of two positive lenses with the first being einzel, and the second representing glued negative and positive lenses. According to the first version, the lens of the first component is biconcave, whereas the first lens of the second component is a meniscus with convexity facing an image, while the second lens is glued biconcave and biconvex lenses. The relation |R₁ ^2k| = |R₃ ^2k| = |R₄ ^2k| is observed, wherein R₁ ^2k; R₃ ^2k; R₄ ^2k are radiuses of the first, third and fourth optical surfaces of the second component. According to the second version, the lens of the first component is plano-concave. Lenses of the second component are meniscuses with their convexities facing an image. The relation |R₁ ^2k| = |R₄ ^2k| is observed.

EFFECT: higher diametre of entrance pupil and angular field within object space with high image quality.

5 cl, 2 dwg

Description

The group of inventions relates to optical instrumentation, can be used in telescopic systems operating in direct and reverse rays, for example, as an afocal nozzle for variable-magnification observation instruments and in laser systems.

The afocal nozzle is installed in front of the telescopic observing system (telescope) in the forward light path to increase the visible increase in the main telescope and in the reverse motion, i.e. rotated through an angle of 180 ° around an axis perpendicular to the optical axis of the system — to reduce the visible increase (I. A. Turygin, “Applied Optics”, M., “Mechanical Engineering”, 1965, p. 223, Fig. 6.28).

When working in a laser system, an afocal nozzle is used to increase the diameter of the laser beam or to reduce its angular divergence ("Theory of Optical Systems", B.N. Begunov et al., M., "Mechanical Engineering", 1981, p.336, Fig. 249).

Known telescopic systems (SU 1811625, publ. 1993, RU 2189064, publ. 2002, G02B 23/00), similar to the Galileo systems, but operating in the reverse direction of the rays.

The closest analogue to both versions of the claimed technical solutions is the Galilean telescopic system (RU 2209455; publ. 2003 G02B 23/00;) containing a lens and an eyepiece, in which the lens consists of two positive lenses, the first is glued from biconvex and biconcave lenses, the second is made in the form of a single convex flat lens, and the eyepiece is a single biconcave lens. The system, calculated for wavelengths of 589 and 1540 nm, has high image quality, a visible increase of 5.5 times with a short length of 45.89 mm. The angular field in the space of objects is 2′30 ″, the diameter of the entrance pupil is 22.5 mm, and the exit pupil is 4.1 mm. When the system operates in the reverse direction of the rays, its entrance pupil becomes the exit pupil with a size of 22.5 mm, and the angular field in the space of objects is 13′45 ″. When using the system, for example, as an afocal nozzle in conjunction with an observation system having an entrance pupil diameter of 30-32 mm, filling it requires an increase in the diameter of the exit pupil and the angular field of the nozzle, which is a consequence of the increased diameter of the entrance pupil of the nozzle.

The task of the invention is the creation of a telescopic optical system with improved performance with high image quality.

The technical result is an increase in the diameter of the entrance pupil and an increase in the angular field of view in the space of objects with high image quality.

The specified technical result is achieved when creating a telescopic optical system, which can be performed in two ways:

According to the first embodiment, the telescopic optical system consists of the first component, made in the form of a single biconcave lens, and the second component, consisting of two positive lenses. The first lens of the second component is single, and the second is glued from a biconcave and biconvex lens. A single lens of the second component is made in the form of a meniscus, convex to the image. The system retains the equality: | R ₁ ^2к | = | R ₃ ^2к | = | R ₄ ^2к |, where R ₁ ^2к ; R ₃ ^2k ; R ₄ ^2k - the radii of the first, third and fourth optical surfaces of the second component. Between the first and second components, a plane-parallel plate, for example a light filter, can be located.

According to the second embodiment, the telescopic optical system consists of a first component made in the form of a single negative lens and a second component consisting of two positive lenses. The first lens of the second component is single, and the second is glued from negative and positive lenses. The lens of the first component is made in the form of a flat-concave, facing concavity to the image. The lenses of the second component are made in the form of menisci, convex to the image. The equality is preserved in the system: | R ₁ ^2к | = | R ₄ ^2к |, where R ₁ ^2к , R ₄ ^2к are the radii of the first and fourth optical surfaces of the second component. A plane-parallel plate, for example a light filter, can be installed in front of the first component. A plane-parallel plate may be glued to the first component.

In Fig.1 shows an optical diagram of a telescopic system according to the first embodiment, in Fig.2 - according to the second embodiment.

The telescopic optical system according to the first embodiment (figure 1) contains a first component made in the form of a biconcave lens 1, and a second component consisting of a single positive meniscus 2, convex to the image, and a positive lens glued from biconcave 3 and biconvex 4 lenses . Between the first and second components can be located plane-parallel plate 5, for example a filter.

The telescopic optical system according to the second embodiment (Fig. 2) contains a first component made in the form of a plane-concave lens 6 facing concavity to the image, and a second component consisting of a single positive meniscus 2, convex to the image, and a positive meniscus glued from negative 7 and positive menisci 8. All menisci are convex to the image. In front of the first component — lens 6 — a plane-parallel plate 9, for example a light filter, can be mounted. It can be glued to lens 6.

The aperture diaphragm (entrance pupil) coincides with the first surface of the lens 1 or lens 6, but can be located in another place.

Telescopic optical systems for both options work as follows. Light rays from an object located at infinity, passing sequentially through the optical elements of the system, come out in the form of parallel beams of rays, forming an image at infinity. The proposed telescopic optical system can also work in the reverse direction of the rays, that is, when the second component is located first along the rays, and after it the first component.

Two variants of the telescopic system are calculated. Option 1 is made in the form of two versions. Version 2 is distinguished by the use of a light filter 5. The design parameters of the telescopic optical system according to the first embodiment are given in Tables 1 and 2.

Options fixed in the visible range of the spectrum:

execution 1 of the first option - in the spectral range of 486 ... 656 nm;

execution 2 of the first option - in the spectral range 510 ... 656 nm;

the second option is in the spectral range of 510 ... 656 nm.

Table 1 CONSTRUCTION PARAMETERS OF THE TELESCOPIC SYSTEM FOR EXECUTION OF THE FIRST OPTION 1 Radius mm Thickness mm Glass mark Refractive index n _e Coeff. variances ν _e Light diameter mm R ₁ ^1k = -68.55 16 d ₁ = l, 3 STKZ 1.662237 57.09 R ₂ ^1k = 20.61 16 d ₂ = 36.16 one R ₁ ^2k = -91.41 27.5 d ₃ = 4 Tk16 1,615192 58.09 R ₂ ^2k = -44.87 28,4 d ₄ = 0.2 one R ₃ ^2k = -91.41 28.6 d ₅ = 2.6 F113 1,624583 36.12 R ₄ ^2k = 91.41 29.6 d ₆ = 7, l K8 1,518294 63.83 R ₅ ^2k = -34.83 30,2

The characteristics of the telescopic optical system according to the first embodiment:

Visible increase 0.34 times Entrance pupil diameter 10.26 mm Angular field in the space of objects 21 °

The design parameters of the telescopic system according to the second embodiment are given in table 3. The characteristics of the telescopic optical system according to the second embodiment:

Visible increase 0.5 times Entrance pupil diameter 16.12 mm Angular field in the space of objects 14 °

table 2 DESIGN PARAMETERS OF THE TELESCOPIC SYSTEM FOR EXECUTION 2 OF THE FIRST OPTION Radius mm Thickness mm Glass mark Refractive index n _e Coeff. variances ν _e Light diameter mm R ₁ ^2k = -68.55 16 d ₁ = 1.3 STK3 1.662237 57.09 R ₂ ^2k = 20.61 16 d ₂ = 5 one R ₁ ^PL = ∞: 17,2 d ₃ = 1.6 ZhS18 1,524994 63.83 R ₂ ^PL = ∞: 17,2 d ₄ = 30.1 one R ₁ ^2k = -91.41 27.5 d ₅ = 4 Tk16 1,615192 58.09 R ₂ ^2k = 44.87 28,4 d ₆ = 0.2 one R ₃ ^2k = -91.41 28.6 d ₇ = 2.6 F113 1,624583 36.12 R ₄ ^2k = 91.41 29.6 d ₈ = 7.1 K8 1,518294 63.83 R ₅ ^2k = -34.83 30,2

Table 3 TELESCOPIC SYSTEM CONSTRUCTION PARAMETERS FOR THE SECOND OPTION Radius mm Thickness mm Glass mark Refractive index, n _e Coeff. variances ν _e Light diameter mm R ₁ ^PL = ∞ 16,2 d ₁ = 1.7 ZhS18 1,524994 63.83 R ₁ ^1k = ∞ 16.1 d ₂ = 1.8 K8 1,518294 63.83 R ₂ ^lK = 25.7 16.1 d ₃ = 37.79 one R ₁ ^1k = -179.47 29th d ₄ = 3.8 Tk16 1,615192 58.09 R ₂ ^2k = -54.45 29.6 d ₅ = 1 one R ₃ ^2k = -47.64 29.7 d ₆ = 2.7 F113 1,624583 36.12 R ₄ ^2k = -179.47 31.1 d ₇ = 5.7 K8 1,518294 63.83 R ₅ ^2k = -36.14 32

Table 4 shows the aberrations of the calculated telescopic system for λ = 546 nm for the first and second variants.

Thus, as a result of the proposed solutions, a technical result is obtained: telescopic optical systems with an increased diameter of the entrance pupil (at least 10.26 mm) and an angular field of view (at least 2W = 14 °) with high image quality are created, which follows from Table .four.

In addition, the proposed variants of the telescopic system are distinguished by increased manufacturability, since the radii: in the first embodiment - three, and in the second - two optical surfaces are equal in absolute value, which makes it possible to unify part of the test glasses and the processing tool.

Table 4 Type of aberration Aberration value, no more The first option, execution 1 The first option, execution 2 Second option Transverse spherical aberration for a point on the axis 0.183 min 0.381 min 0.05 min Transverse aberration of a wide inclined beam in the meridional section for the field of view 2W = 21 ° 1,366 min 1.57 min 0.05 min Transverse aberration of a wide inclined beam in a sagittal section for the field of view 2W = 21 ° 1,375 min 1,621 min 0.027 min Meridional astigmatic segment X _m for the field of view 2W = 21 ° -0.0285 diopters -0.0355 diopters 0.0188 diopters Sagittal astigmatic segment X _s for the field of view 2W = 21 ° -0.0283 diopters -0.0306 diopters -0.002 diopters Distortion for the field of view 2W = 21 ° -1.4% -1.4% -0.71%

Claims (5)

1. Telescopic optical system, consisting of the first component, made in the form of a single biconcave lens, and the second component, consisting of two positive lenses, the first of which is a single lens, and the second is glued from a biconcave and biconvex lens, characterized in that the single the lens of the second component is made in the form of a meniscus, convex to the image, and the equality
| R ₁ ^2k | = | R ₃ ^2k | = | R ₄ ^2k |,
where R ₁ ^2k ; R ₃ ^2k ; R ₄ ^2k - the radii of the first, third and fourth optical surfaces of the second component. 2. The telescopic optical system according to claim 1, characterized in that between the first and second components there is a plane-parallel plate, for example, a filter. 3. The telescopic optical system, consisting of the first component, made in the form of a single negative lens, and the second component, consisting of two positive lenses, the first of which is a single lens, and the second is glued from a negative lens and a positive lens, characterized in that the lens of the first component is made in the form of a flat-concave, and the lenses of the second component are made in the form of menisci, convex to the image, and the equality
| R ₁ ^2k | = | R ₄ ^2k |,
where R ₁ ^2k ; R ₄ ^2k - the radii of the first and fourth optical surfaces of the second component. 4. The telescopic optical system according to claim 3, characterized in that a plane-parallel plate, for example a light filter, is installed in front of the first component. 5. The telescopic optical system according to claim 4, characterized in that the plane-parallel plate is glued to the first component.

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