RU1806401C - High-power camera objective - Google Patents

Abstract

Usage: in the field of optical instrumentation, it belongs to the class of lenses and can be used in equipment for film, photo and television shooting. The essence of the invention lies in the fact that in the lens the first component is made in the form of a two-convex lens, in front of which, at a distance of 0.40-0.45 of the focal length of the lens, a single double-concave lens is mounted, while the third component is made in the form of a single a biconvex lens, spaced from the second component at a distance of 0.30-0.35 of the focal length of the lens. In the fourth component, the negative lens is made in the form of a meniscus facing concavity to the space of objects and is located behind the biconvex, the fifth component is glued from biconvex and biconcave lenses, and in the fourth and fifth components the refractive index of the negative lens material exceeds that of two convex not less than 0.18 with a dispersion coefficient difference of not less than 35.0, and the aperture diaphragm is located between the first and second components. 2 ill. (L

Description

The invention relates to the field of optical instrumentation and can be used in apparatus for photographing and televising.

The purpose of the invention is to increase the angular field in the space of objects in the absence of vignetting, to ensure the same aperture within the entire linear field in the image space while improving image quality.

In FIG. 1 is a schematic optical diagram of a fast photographic lens; in FIG. 2 - graphs

residual aberrations and curve of the function of the distribution of illumination over a linear field in the image space (F -1.0).

The optical scheme of the proposed lens contains sequentially located: along the beam, a biconcave lens 1, the first component, made in the form of a biconvex lens 2, aperture diaphragm 3, the second component, made in the form of a positive meniscus 4, facing the concavity to the image space A third component made in the form of a single biconcave lens 5, four

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a fifth component glued from a biconvex lens 6 and a negative meniscus 7 facing concavity to the space of objects, and a fifth component made of glued from a biconvex 8 and biconcave 9 lenses.

As is known, the development of the angular field in fast lens lenses is hindered by the possibility of physical transmission through optical surfaces within their allowable light diameters of wide inclined beams, as well as their aberrations, including chromatic aberrations of these beams. In general, both cannot be avoided. Therefore, they agree or resort to the so-called trimming of inclined beams or, what is the same, to their vignetting. And since in almost all optical schemes of lenses and without vignetting, for wide beams, the relative aperture decreases as their angle of inclination increases, with the introduction of vignetting this process is accelerated with all the ensuing consequences.

In order to eliminate the indicated reasons, the first component is made in the form of a biconvex lens 2 and a single double-concave lens is installed in front of it at a distance of 0.40-0.45 of the focal length of the lens. 1. The optical power of the system (lenses 1 and 2), and its angular magnification yK 1.0. This design allows to reduce the field angle in the space where the material diaphragm is located, and provides the ability to actively “both on the aberrations of wide inclined beams when passing them at the system inlet without vignetting, and on field aberrations, and therefore contributes to the development of angular floor in the space of objects.

, The second component is made in the form of. false meniscus 4, facing concavity to the space of images, and the third - in the form of a single biconcave lens 5, spaced from the second component at a distance of 0.30-0.35 of the focal length of the lens. The optical power of the system (lenses 4 and 5) is 0, and its angular increase is about 1.0. Such a construction promotes the development of an angular field, i.e. It allows one to actively influence field aberrations, as well as aberrations of wide inclined beams when passing through them in the middle part of the system without vinishing.

Part of the system (1.2.4 m 5 lenses) has an optical power of Ф 0 and an angular magnification of a) 1.0, which makes it possible to obtain an area

the entrance pupil of the lens for wide inclined beams within an angular field greater than or equal to the area of the entrance pupil to the axial beam. This makes it possible to obtain the same relative aperture for all wide beams, and therefore, the same aperture within the linear field of the image space of the lens. At the same time, the design allows one to develop an angular field, increase the posterior focal segment and actively influence all aberrations, including the chromatic aberrations of wide inclined beams without vignetting them.

The fourth component is glued from a biconvex lens 6 and a negative meniscus 7, facing a concavity to the space of objects. In this case, the refractive index of the meniscus material exceeds that of a biconvex lens by no less than 0.18 at. differences in the dispersion coefficients of their materials of not less than 35D. Such a component design determines the optical power of the lens, promotes the development of the angular field, the relative aperture for wide oblique beams and the correction of field aberrations, including their color analogues. . .

The fifth component is glued from a biconvex 8 and biconcave 9 lenses, and the refractive index of the material of the biconvex lens exceeds the refractive index of the biconcave lens by at least 0.18 when the dispersion coefficient of the materials of the biconvex and biconcave lenses is not less than 35 , 0. This component design provides optical power to the lens, allows wide inclined beams to be transmitted without vignetting, to develop an angular field in the space of objects and to actively influence the color aberrations of the entire system.

The task of developing an angular field, obtaining the same aperture within a linear field in the image space, while improving image quality, is one of the most difficult tasks in computational optics. Therefore, its solution is possible only if all the properties of the elements of the optical scheme are taken into account, as well as their interaction. The exclusion from such an interaction of at least one property from the elements makes it impossible to solve this problem. Therefore, only the totality of all elements of the circuit allows us to achieve a given goal, i.e. get a positive decision.

40,0

1 / 1.47

0.6907Р

0.5893

0.48613-0.65628

A fast photographic lens has the following basic optical characteristics:

angular field in

space

subjects, hail

relative

hole

back focal

segment mm

basic length

waves, microns

achromatization region, microns

The proposed design of a fast photographic lens, unlike the prototype, allows to increase the angular field in the space of objects by 11.5 (prototype 2 about 28.5) in the absence of vignetting (in the prototype vignetting on the edge of the floor is both the upper and lower 50 %), to obtain the same aperture within the entire linear field in the image space (see the graph from the wind distribution of Fig. 2) and improve the image quality within the entire increased angular field (see aberration graphs, Fig, 2).

An additional technical advantage is that the rear focal length is increased by 0.19F (prototype S 0.5015F.

The benefit of the national economy from the proposed invention may be that it is possible to create a competitive 6-object7 world market which can be used in various fields of science and technology.

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Claims (1)

 The claims A fast photographic lens containing an aperture diaphragm and five components, the first of which is 5 single positive lenses, the second is a single positive meniscus facing concavity to the image space, the third is a negative lens containing a double-concave lens, the fourth is a positive double-glued lens, of which one is two convex convex, the other is negative, and the fifth is a positive lens, characterized in that, in order to increase the angular field in space 5 objects in the absence of vignetting, ensuring the same aperture within the entire linear field in the image space while improving image quality, a single biconcave lens is inserted into the lens, mounted at a distance of 0.40-0.45 of the focal length of the lens from the first component made in the form of a biconvex lens, the third component 5 is made in the form of a single lens mounted at a distance of 0.30-0.35 of the focal length of the lens from the second component, in the fourth component, the negative lens is made in the form of a meniscus mounted behind a two-convex lens, the fifth component is made of two convex and biconcave lenses, in the fourth and fifth components the refractive index of the material is negative 5 lenses exceed the refractive index of the material of positive lenses by at least 0.18 with a dispersion coefficient difference of at least 35, and an aperture aperture is located between the first and 0. second components. 56} 8 9 . o -0.6 ..--- L / -g- && ./ | UN, Chi ° 5 h Lu. ..--- L / -g- && - “. Jfo .a / ax o FIG 2