RU2690044C2 - Eyepiece - Google Patents

Abstract

FIELD: optics.SUBSTANCE: eyepiece can be used in two-channel optoelectronic devices in various operating conditions. Eyepiece comprises beam-splitting prism in form of cube-prism, after which along the beam a plane-concave negative lens is placed, which faces the object space with a flat surface, and two biconvex positive lenses. Following relation is satisfied: ϕ= - (0.4÷1.2)⋅ϕ, where ϕis the optical power of the negative lens; ϕis eyepiece optical power.EFFECT: technical result is an increase in the exit pupil removal to a value equal to f, while maintaining high optical characteristics.1 cl, 4 dwg, 1 tbl

Description

The present invention relates to the field of opto-electronic equipment and can be used as an eyepiece for two-channel day-night vision devices in a wide variety of operating conditions.

Known eyepiece (patent RU 2155980 C1), containing three components, the first of which is positive gluing, consisting of negative and biconvex positive lenses, the second and third positive and negative lenses. The eyepiece also contains a beam-splitting prism located in front of the first component, and has the ability to display auxiliary information through the beam-splitting prism.

The disadvantage of this eyepiece is a narrow field of view in the additional channel (only a few degrees) and a relatively short anterior segment, which does not allow installing a microdisplay into the additional channel.

The closest in technical essence is the eyepiece (patent RU 2439631 C1, publ. 10.01.2012) containing a beam-splitting prism installed in front of the first lens component, and a convex single lens along the beam, facing a flat surface to the object space, and gluing biconvex along the beam. and negative lenses facing a biconvex lens to the space of objects. The eyepiece has an increased angle of view of the additional channel, equal to the angle of the field of view of the main channel, which makes it possible to work with the LCD display in the additional channel.

The disadvantage of this eyepiece is the small removal of the exit pupil, which is 0.85⋅f _ok , which limits its use in modern observational devices using personal protective equipment.

The present invention is to increase the removal of the exit pupil to a value equal to ⋅f _ok , while maintaining high optical characteristics.

The technical result, due to the task, is achieved by the fact that in the eyepiece containing the beam-splitting prism in the form of a cube-prism, unlike the known, after the cube-prism along the beam a flat-bent negative lens is set, facing the object space with two flat convex lenses, while the following relationship:

ϕ _о.л. = - (0.4 ÷ 1.2) ϕ _ok ,

where ϕ _о.л. - optical power of the negative lens;

ϕ _ok is the optical power of the eyepiece.

This eyepiece ensures the removal of the exit pupil to a value equal to ⋅f _ok , while maintaining high optical characteristics. The optical scheme of the eyepiece is shown in figure 1.

The eyepiece contains the beam-splitting cube-prism 1, the negative lens 2, the positive lenses 3 and 4. The eye of the observer is placed in the exit pupil 5.

The figure 2 shows the graphs of curvature and astigmatism, in figure 3 a graph of relative distortion, in figure 4 a graph of spherical aberrations for a point on the axis. The linear field of the eyepiece m = 16 mm, indicated on the scale of ordinates in the graphs of figures 2 and 3 corresponds to an angular field of the eyepiece ~ 40 degrees (for both channels). The scale value of 0.5 mm in the graph of figure 2 corresponds to ~ 0.95 diopters. The graph of spherical aberrations for a point on the axis in figure 4 is shown for a pupil diameter of an eye of 5.1 mm. All curves are for a wavelength of 587.6 nm.

The design parameters of the eyepiece design are given in table 1.

The parameters of this version of the eyepiece:

- angle of view in the image space in both channels ... 42 °;

- exit pupil diameter ... 6 mm;

- distortion at the edge of the visual field ... ≤5%;

- removal of the exit pupil ... 23 mm;

- focal length ... 23 mm;

- angular aberrations for the edge of the field of view ... ≤1 dptr.

The principle of the eyepiece is as follows.

The luminous flux from the subject plane A passes through the beam-splitting cube-prism 1 and lenses 2, 3 and 4, and enters the eye of the observer located in the exit pupil 5 of the eyepiece. Auxiliary information from the LCD, located in plane B, passes through the beam-splitting cube-prism 1, lenses 2, 3 and 4, and enters the exit pupil 5 simultaneously with the main image from the subject plane A. To increase the distance of the exit pupil, perform the following relationship:

ϕ _о.л. = - (0.4 + 1.2) - * + _ok ,

where ϕ is _about . _l is the optical power of the negative lens;

ϕ _ok is the optical power of the eyepiece.

As can be seen from the calculations on the charts in figures 2, 3 and 4, this eyepiece with the removal of the exit pupil, increased to a value equal to f _OK , ensures the preservation of high optical characteristics.

Claims (4)

An eyepiece containing a cube-prism beam-splitting prism, characterized in that after a cube-prism a flat-bent negative lens is set along the beam, facing a flat surface to the space of objects, and two biconvex positive lenses, and the following relationship holds: ϕ _о.л. = - (0.4 ÷ 1.2) ϕ _ok , where ϕ _о.л. - optical power of the negative lens; ϕ _ok is the optical power of the eyepiece.

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