RU2656015C1 - Optical system - Google Patents

Abstract

FIELD: optics.

SUBSTANCE: invention can be used in optical devices that form an image with a significant removal of the entrance or exit pupil. Optical system contains four components along the path of the rays. First component is a single positive lens and a negative three-glazed lens, containing the first biconcave lens along the rays, the second and third lenses in the form of positive meniscus facing concavities to the image. Second and third components are made in the form of positive single lenses, equal in values to the radii of optical surfaces, thicknesses and grades of glasses and facing each other by convex spherical surfaces of curvature equal in absolute value. Fourth component is made in form of a single negative meniscus, which is turned by a concavity to the image.

EFFECT: high image quality.

1 cl, 1 dwg, 2 tbl

Description

The invention relates to optical instrumentation and can be used in various optical devices that form an image with a significant removal of the input or output pupil.

Known optical system described in the patent application RU No. 96111476/28, IPC G02B 25/00, publ. 12/27/1997, containing seven sequentially located along the optical axis of the lens. The first from the plane of the entrance pupil is a single lens made in the form of a meniscus facing concavity to the entrance pupil, the second is a positive lens with an aspherical surface facing the plane of the exit pupil, the third is a lens glued from the negative and positive lenses, the fourth is a negative lens, glued from the positive and negative lenses, and a single negative lens located behind the fourth negative glued lens. This optical system projects the plane of objects located in the front focus to infinity in the space of images. However, this optical system has a complex structure and lack of manufacturability, since it contains one aspherical parabolic surface, and the three lenses of this optical system are made of lanthanum glass of the CTK19 superheavy crown group.

The closest analogue to the claimed technical solution is the optical system described in US patent No. 2549158, NKI 88-57, FIG. 3, publ. 04/17/1951, This optical system projects the plane of objects located in the front focus, to infinity in the space of images. It consists of six lenses in four components along the rays: the first component is a glued positive lens, including along the rays a positive meniscus facing concavity to the object, a biconcave lens and a biconvex lens; the second component is a biconvex lens, in which the second surface is steeper than the first; the third component is a convex flat lens, the plane facing the image, and the fourth component, the positive meniscus, facing the concavity to the image. However, this optical system, calculated in the reverse direction of the rays, recalculated to a focal length of 146, 91 mm for a wavelength of 640 nm with a relative aperture of 1: 10.06, the angular field in the image space 2W = 16 ° when the exit pupil is projected at 59.1 mm, after the last optical surface has insufficient image quality. So, in this optical system, with an angular field of 2W = 16 °, a significant transverse aberration is detected in the meridional section - 0.046 mm, as well as a significant meridional astigmatic segment equal to 1.1612 mm.

The task of the invention is the creation of an optical system with enhanced image quality.

The technical result is an increase in image quality.

This is achieved by the fact that in an optical system containing four components along the rays, of which a three-glued lens is included in the first component, the second and third components are made in the form of positive single lenses, the fourth component is made in the form of a single meniscus, facing the concavity to the image, unlike the known one, in the first component there is a single positive lens in front of the three-glued lens, the three-glued lens is made negative, the first lens along the rays entering the three-glued lens, hollow-concave, and the second and third lenses of the three-glued lens are made in the form of positive menisci facing concavity to the image, the second and third components are identical in values of the radii of the optical surfaces, thicknesses and brands of glasses, and the convex spherical optical surfaces of the radii of curvature of the second and third the components are facing each other, and the fourth component is negative.

The drawing shows an optical diagram of the proposed optical system.

The optical system contains four components along the rays, of which a three-glued lens is included in the first component, in front of which there is a single positive lens 1, which can be made convex flat, convex to the object, the three-glued lens is negative, the first lens 2 in the direction of entry into a three-glued lens, biconcave, and the second lens 3 and the third lens 4 of the three-glued lens are made in the form of positive menisci facing concavities to the image. The second and third components are made in the form of positive single lenses 5 and 6, identical in values of the radii of the optical surfaces, thicknesses and brands of glasses, with convex spherical optical surfaces of the same modulus of radius of curvature of the lenses 5 and 6 facing each other, the fourth component is made in in the form of a single negative meniscus 7, facing concavity to the image.

The proposed optical system operates as follows. The luminous flux from an object located in the front focal plane enters the optical system, where it passes through lenses 1, 2, 3, 4, 5, 6, 7 and forms an image of the object at infinity. The exit pupil is located after the last optical surface at a distance of 59.1 mm. The proposed optical system can also work as a lens, i.e. in reverse rays.

In accordance with the proposed solution, a specific design of the optical system with a remote exit pupil was calculated, corrected in the spectral range from 600 to 660 nm, for the main wavelength of 640 nm.

The design parameters of the proposed optical system are shown in table 1.

Characteristics of the calculated optical system:

focal length 146.91 mm front focal length -44.08 mm relative hole 1: 10.06 angular field in image space 16 deg.

Table 2 shows the aberrations of the proposed optical system for a wavelength of 640 nm in the reverse path of the rays, as well as the closest analogue in the reverse path of the rays, calculated at a focal length of 146.91 mm when the entrance pupil is taken out by 59.1 mm. From table 2 it follows that the proposed optical system has a higher image quality than the closest analogue.

Thus, a technical result is obtained: an optical system with improved image quality is created.

Claims (1)

An optical system containing four components along the rays, of which a triple-bonded lens is included in the first component, the second and third components are made in the form of positive single lenses, the fourth component is made in the form of a single meniscus facing concavity to the image, characterized in that in the first component in front of the three-glued lens there is a single positive lens, the three-glued lens is made negative, the first lens along the rays entering the three-glued lens is biconcave, and the second and three The lenses of the three-glued lens are made in the form of positive menisci facing concavities to the image, the second and third components are identical in values of the radii of the optical surfaces, thicknesses and grades of glasses, and the convex spherical optical surfaces of the radii of curvature of the same modulus are facing each other , and the fourth component is negative.

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