RU2282223C1 - Optical sight with alternating magnification - Google Patents

Abstract

FIELD: optical sights and telescopes operating in the visible range of radiation spectrum.

SUBSTANCE: the sight with an alternating magnification has a three-lens objective, sight reticule, field component, two-component panchromatic erecting system, range-finding reticule, collective lens and an ocular installed in succession in the direction of rays. The objective has cemented first two lenses-biconvex and negative ones, and the third lens-singular positive meniscus turned with the convexity to the object. The biconvex and singular lenses are made of the same material with dispersion factor ν_D, which corresponds to condition 50≤ν_D≤70 that is more than the dispersion factor of the material of the negative lens by 2 to 2.5 times. The relations given in the patent claim are fulfilled between the focal distances of the cemented lens, objective, biconvex lens, negative lens and singular lens.

EFFECT: improved accuracy characteristics, and namely, reduced errors of the sight angle.

1 dwg, 2 tbl

Description

The invention relates to optical instrumentation, in particular, to the sights used in conducting aimed fire from weapons, or to telescopes operating in the visible region of the radiation spectrum.

Known optical system of the sight with variable magnification [1], which contains a lens, pancratic wrapping system, a collective lens and an eyepiece. This scheme has a longitudinal size, L = 313.7 mm, a relative lens aperture D _sp / f '= 1: 3.5 and a resolution limit in the center of the angular field at a maximum magnification of not more than 10 ".

The closest in technical essence to the proposed solution is a variable zoom sight [2], constructed according to the optical scheme: a three-lens lens, a fixed field component, a pancratic wrapping system that includes two components, a collective lens and an eyepiece. The sighting device can contain an aiming grid immediately behind a three-lens lens, and after a pancratic reversing system, a rangefinder grid. In the example given in [2], the visible increase in the telescopic system is Γ = 3.2 ^X ... 9.8 ^X. The resolution limit of the telescopic system is not more than 6 "in the center of the angular field at maximum magnification (G = 9.8 ^X ). The sight lens has a rear focal length f '= 119.7 mm, the relative aperture D _sp / f' = 1: 3, and the angular field in the space of objects is 2ω = 7.6 ° ... 2.5 °. In this case, the longitudinal spherical aberration of the lens (ΔS '), calculated for a distance of -400 m for the main wavelength (λ _D ) is for the zone m = 14 1 mm ΔS _'0,707 = -0,003 mm, edge - m = 20,0 mm ΔS' _cr = 0.137 mm installation reticle in the image plane of the best lens is irremovable. rodolny parallax (ΔS _'m -Δ): Zone m = 14,1 mm (ΔS' -Δ _0,707) = - 0,082 mm for the edge - m = 20,0 mm (ΔS _{'cr -Δ.)} = 0.058 mm , which causes an additional angular parallax on the terrain equal to ± 16 ", with the position of the eye on the edge and in the area of the exit pupil of the sight. The large magnitude of the angular parallax is a disadvantage of the considered sighting system with variable magnification, since its use in an optical sight increases the error of the aiming angle when moving the eye in the plane of the exit pupil of the sight.

The objective of the invention is the creation of a sight with variable magnification with improved accuracy characteristics, namely with a reduced error of the angle of aim.

The technical result due to this task is achieved by the fact that in a sight with variable magnification, containing a three-lens lens, an aiming reticle, a field component, a two-component pancratic wraparound system, a rangefinder reticle, a collective lens and an eyepiece, sequentially installed along the rays of the beam, in contrast to the well-known in the lens, the first two lenses are biconvex and negative - glued, and the third lens is a single positive meniscus convex to the object, and biconvex and about inochnaya lenses are made from a material having a dispersion coefficient ν _D, which corresponds to the condition 50≤ν _D ≤70, which is 2 ... 2,5 times the dispersion coefficient of the negative lens material, wherein the following conditions are satisfied:

f ' _ckl = (3 ... 4) f'_about;

f ' ₁ = (0.8 ... 1.2) f'_about;

f ' ₂ = - (1 ... 1,5) f'_about;

f ' ₃ = (1 ... 1,5) f' _rev ,

where f ' _ccl , f' _about , f ' ₁ , f' ₂ , f ' ₃ are the focal lengths of the glued lens, lens, biconvex lens, negative lens, and single lens, respectively.

The drawing shows an optical diagram of an optical sight with variable magnification and the beam path in it at 2ω = 0 °.

The variable zoom sight consists of a lens 1, made in the form of a three-lens design, consisting of a biconvex lens 2, glued with a negative meniscus 3, convex to the image and a single positive meniscus 4, convex to the object, field component 5, pan-wrap system 6 consisting of two differentially moving components 7, 8, a collective lens 9 and an eyepiece 10. The observer's eye is located in the exit pupil of the optical sight 11. In the image plane A lens Nia reticle 12 is set in the image plane in the relay system - rangefinder 13. The mesh size L corresponds to the maximum longitudinal dimension of the proposed optical sight on its optical axis.

An optical sight with variable magnification works as follows: the luminous flux passes through the lens 1 and is focused in the front plane of the image A; after passing through the field component 5 and the wrapping system 6, consisting of two differentially moving components 7, 8, it focuses in the rear plane of image B. This intermediate image is observed through the collective lens 9 and eyepiece 10 with the eye located in the exit pupil of the sight 11. In this scheme the eyepiece 10 can either have a constant diopter setting at (-0.75) ± 0.25 diopters or be able to diopter move the entire eyepiece by ± 5 diopters. In the front and rear planes of the image, the aiming and rangefinder grids can be installed, applied to plane-parallel plates 12, 13 and the flat surface of the collective lens 9, while the grid installed in the front plane of the image A of the lens — the aiming grid — can be made in the form of gluing, consisting of two plane-parallel plates 12, which is necessary to reduce the "indicator of the light locomotive of rotation" when counteracting unmasking optoelectronic systems. The change in the visible increase in the scope within T = 3.2 ^X ... 9.9 ^X occurs as a result of the differentiated movement of the components 7.8, which leads to a change in the air gaps l ₁ , l ₂ , l ₃ , while the front A and rear B plane of the image remain in the same position.

In accordance with the proposed solution, a variant of the optical sight was calculated. It has the design parameters of the optical system shown in table 1.

An optical sight with the following technical characteristics was obtained: a visible increase in the telescopic system G = 3.2 ^X ... 9.9 ^X , the rear focal length of the lens f ' _r = 120 mm and its relative aperture D _sp / f' = 1: 3, angular field in the space of objects 2ω = 7.6 ° ... 2.5 °. The exit pupil is located at a distance of 70 mm from the last surface of the eyepiece and has a diameter of 10.2 ... 4 mm. The longitudinal size of the sight in this case is L = 291 mm. The resolution limit of the sight is not more than 6 "in the center of the angular field at maximum magnification (G = 9.9 ^X ). The transmittance of the optics of the sight is at least 70%.

The optical scheme of the proposed sight is made with a lens in which the longitudinal spherical aberration shown in table 2 is less than the diffraction depth of the lens.

In optical sights, the plane of the strokes of the reticle must strictly coincide with the plane of the sharp image of the observed target. This requirement with a given accuracy is met when assembling and adjusting sights. However, in the absence of noticeable blurring of the image in the sight, there may be unavoidable angular parallax due to the longitudinal spherical aberration of the lens, which causes an additional error in the aiming angle with lateral displacement of the eye in the plane of the exit pupil of the sight.

In the proposed lens at any eye shift in the plane of the exit pupil, the angular parallax on the ground due to the longitudinal spherical aberration of the lens does not exceed the diffraction limit of the lens resolution equal to ± 3 ", which is significantly lower than the value of the additional angular parallax for the sight with variable magnification [2] equal to ± 16 ". For this optical system, the angular parallax on the ground is determined only by the accuracy of assembly and adjustment of the “lens-sighting grid” assembly, which significantly reduces the error in the aiming angle when moving the eye within the exit pupil. Thus, the achievement of the technical result.

Currently, according to the optical sight scheme, a series of modifications of the product manufactured according to the design parameters of the lens are commercially available; the obtained optical characteristics satisfy the functional purpose of the sights.

Information sources

1. Vizir with variable magnification "1P21", 1982, the development of the Novosibirsk Instrument-Making Plant. Optical circuit AL3.812.124, copies are in the file on application No. 99119299 (patent RU 2157556).

2. Vizir with variable magnification. Patent RU 2157556, IPC 7 G 02 B 23/14, F 41 G 1/38, publ. 2001 year

table 2
Axis point for Gmax m λ ₀ = D λ ₁ = F λ ₂ = C Δ (S ' _F -S' _C ) Tg σ ' ΔS ' ΔY ' ΔS ' ΔY ' ΔS ' ΔY ' 0 0 0 0 -0.0064 0 0.0863 0 -0.0927 10 0,084 -0.0079 -0,0007 0.0067 0,0005 0.0815 0.0068 -0.0748 14.1 0.119 -0.0112 -0.0013 0,0201 0.0024 0,0768 0.0091 -0.0567 17.3 0.146 -0.0098 -0.0014 0,0336 0.0049 0,0719 0.0105 -0.0383 twenty 0.169 -0.0035 -0,0006 0.0472 0.0080 0.0670 0.0113 -0.0198

Claims (1)

Variable-magnification optical sight containing a three-lens lens, a reticle, a field component, a two-component pan-wrap system, a range finder, a collective lens and an eyepiece sequentially installed along the rays of the beam, characterized in that the first two lenses are biconvex and negative are glued, and the third lens is a single positive meniscus convex to the object, and the biconvex and single lenses are made of the same material with a dispersion coefficient uu ν _D, which corresponds to the condition 50≤ν _D ≤70, which is 2 ÷ 2,5 times the dispersion coefficient of the negative lens material, wherein the following conditions are satisfied: f ' _SCL = (3 ÷ 4) f'_about; f ' ₁ = (0.8 ÷ 1.2) f'_about; f ' ₂ = - (1 ÷ 1,5) f'_about; f ' ₃ = (1 ÷ 1,5) f' _rev , where f ' _ccl , f' _about , f ' ₁ , f' ₂ , f ' ₃ are the focal lengths of the glued lens, lens, biconvex lens, negative lens, and single lens, respectively.