RU81347U1 - WIDE-OPEN Eyepiece - Google Patents

Abstract

The utility model relates to optical instrumentation, namely, to the eyepieces and can be used in observational instruments. A wide-angle eyepiece of four components, the first and second of which are positive double-glued lenses, the first component consisting of negative and positive lenses, characterized in that the difference in the dispersion coefficients of the materials of the positive and negative lenses in the first component is at least 25, and the positive double-glued lens of the second component consists of positive and negative lenses, the third component is made in the form of a positive meniscus, convex surface facing the space of objects, fourth The ith component is a negative meniscus facing a space of objects with a convex surface and the absolute value of its focal length is 3.3 ... 4 of the focal length of the eyepiece. The proposed wide-angle eyepiece in comparison with the prototype provides an increase in the front working segment, an increase in the removal of the exit pupil, an increase in the relative aperture of the eyepiece, and an increase in image quality over the entire field of view. 4 ill.

Description

The utility model relates to optical instrumentation, namely, to the eyepieces and can be used in observational instruments.

Known eyepiece with a remote exit pupil [1], containing four single lenses, the first of which is a negative meniscus facing a convex surface to the space of objects, the second and third lenses are biconvex, and the fourth is biconcave, while the absolute values of the optical power of the lenses are selected from the ratio of 1.9: 1.1: 0.78: 1.2, the difference in the refractive indices of materials of positive and negative lenses is not more than 0.002, and the difference in their coefficients of average dispersion is not less than 22.

The disadvantage of this eyepiece is a small front working segment of 0.874 of the focal length of the eyepiece f 'and a low relative aperture of 1: 6.

Of the known eyepieces, the closest to the proposed utility model according to the technical solution is the eyepiece [2], which contains four components, the first and second of which are positive double-glued lenses consisting of negative and positive lenses, the third is a single positive lens, and the fourth is positive meniscus, convex surface facing the space of objects.

However, this eyepiece has an imaginary anterior segment, a small removal of the exit pupil of 0.58 f ' _{ok, a} small relative aperture of 1: 9.6 and poor image quality due to large aberrations in a wide inclined beam of rays.

The objective of the proposed technical solution is to increase the front working segment, increase the removal of the exit pupil, increase the relative aperture of the eyepiece and improve image quality throughout the field of view.

The problem is achieved in that in the wide-angle eyepiece of four components, the first and second of which are positive double-glued lenses, while the first component consists of negative and positive lenses, unlike the prototype, the difference in the dispersion coefficients of the materials of the positive and negative lenses in the first component does not less than 25, the positive two-glued lens of the second component consists of positive and negative lenses, the third component is made in the form of a positive meniscus facing convex surface to the space objects, the fourth component is a negative meniscus facing a convex surface toward the object space and the absolute value of its focal length is 3.3 ... 4 the focal length of the eyepiece.

The use in the first component in the positive and negative lenses of two different materials with a dispersion coefficient difference of at least 25, gluing the second component from the positive and negative lenses, the third component in the form of a positive meniscus, convex surface facing the space of objects, and the fourth component in the form negative meniscus facing a convex surface toward the object space, the selection of the focal length of the fourth component is in the range of 3.3 ... 4 f _'ok allowed withdrawn chit front working distance up to 0,91 f _'ok upon removal of the exit pupil equal to 0,83 f' _ok, the eyepiece to increase the aperture ratio to 1: 4.3, to correct oblique aberrations wide beam of rays and thus provide good image quality within the angular field of view 2W = 52.

Figure 1 shows the optical scheme of the proposed wide-angle eyepiece.

Figure 2, 3, 4 presents graphs of the aberrations of the eyepiece in the Gauss plane when calculated in the reverse direction with the exit pupil diameter of 7 mm for the visible region of the spectrum.

The wide-angle eyepiece (figure 1) contains in the direction of the beam four components 1-4. The first component 1 is a positive two-glazed lens, consisting of a negative and a positive lens, while the negative lens is made in the form of a meniscus facing a convex surface to the space of objects, and the positive one is in the form of a biconvex lens. The second component 2 is also made in the form of a positive double-glued lens, consisting of positive and negative lenses, with the positive lens made biconvex and the negative biconcave. The third component 3 is made in the form of a positive meniscus facing a convex surface to the image space. The fourth component 4 is a negative meniscus with a convex surface facing the space of objects. The design parameters of the eyepiece are given in the table.

Table R D n _e ν _e 268.5 4,5 1.7616 27.16 54.08 fifteen 1.6940 54.48 -44.36 0.3 53.58 16.5 1.6615 50.59 -41.14 four 1.7616 27.16 1520.5 0.3 31.77 7 1.6734 46.83 42.76 0.3 21.18 4,5 1.7616 27.16 15,56

The focal length of the fourth component is equal to -117.8 mm, which is the absolute value of 3,93 f _'ca.

The wide-angle eyepiece works as follows: diverging beams of rays emanating from the points of a flat object located in the front focal plane of the eyepiece are converted by components 1-4 into parallel and build an image of the plane of objects on the retina of the eye. The large front working distance, which is 0.91 of the eyepiece focal length, allows you to place special prisms or mirrors between the plane of the eyepiece objects and its first component, with which you can enter various service information in the field of view, for example, the distance to the target in sights.

Large removal of the exit pupil, at least 0.83 of the focal length of the eyepiece, allows the observer to comfortably place the pupil of the eye in the exit pupil of the eyepiece and examine the field of view of the eyepiece and service information.

The high image quality of the eyepiece (see figure 2, 3, 4) allows us to distinguish the smallest details in the image of the object, that is, to increase the range of detection and recognition of objects of interest by telescopes, in which the proposed eyepiece can be used. A sufficiently large relative aperture of 1: 4.3 allows you to work in the twilight lighting of objects of observation.

The main characteristics of the wide-angle eyepiece:

Focal length mm thirty Diameter of exit pupil, mm 7

Distance from first surface

to the subject, mm 27.3 Removal of the exit pupil, mm 25 Linear field of view, mm 26 Eyepiece Length, mm 52,4

INFORMATION SOURCES

1. A.S. SU. No. 1721578. Eyepiece with remote exit pupil.

2. The patent of Germany No. 2001953. Wide-angle eyepiece (prototype).

Claims (1)

A wide-angle eyepiece of four components, the first and second of which are positive double-glued lenses, while the first component consists of negative and positive lenses, characterized in that the difference in the dispersion coefficients of the materials of the positive and negative lenses in the first component is at least 25, and the positive double-glued lens of the second component consists of positive and negative lenses, the third component is made in the form of a positive meniscus, convex surface facing the space of objects, fourth the ith component is a negative meniscus facing a space of objects with a convex surface and the absolute value of its focal length is 3.3 ... 4 of the focal length of the eyepiece.