RU2427864C1 - Eyepiece with pinhole exit pupil - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: eyepiece has four components in the direction of the beam path. The first component is in form of a negative meniscus 1, whose concave surface faces the object space. The second component is in form of a plane-convex lens 2, whose flat surface faces the object space. The third component comprises a biconcave 3 and a biconvex lens 4 glued together, and the convex surface of this component faces the exit pupil. The fourth component is in form of a plane-convex lens whose convex surface faces the exit pupil.

EFFECT: improved design.

5 dwg, 1 tbl

Description

The invention relates to optical instrumentation, namely, eyepieces, and can be used in digital displays, various observation devices, including night vision devices with image formation on a CCD matrix.

A microscope eyepiece is known containing a positive double-glued meniscus facing a concave surface to the space of objects, a biconvex lens and a positive meniscus facing a concave surface to the image space, the lenses of the glued meniscus being made in the form of positive and negative menisci [SU 1739341 A1, 1992]. The disadvantages of this eyepiece are insufficient image quality and insufficient removal of the exit pupil.

Also known is an eyepiece with a remote exit pupil, consisting of a first component installed sequentially on the optical axis, which includes a plano-convex lens facing a space of objects with a flat surface, a second component made in the form of a gluing consisting of a positive biconvex lens and a negative meniscus facing a convex surface to the image space, and the third component, made in the form of a positive gluing, consisting of biconvex and biconcave lenses, gap of the concave surface to the image space [BY C1 6216]. The disadvantage of this eyepiece is also insufficient image quality and insufficient removal of the exit pupil (1.07 focal length of the eyepiece).

Closest to the proposed invention in technical essence is an eyepiece that contains three components, the first of which is a negative meniscus facing a concave surface to the object, the second is a biconvex lens, and the third component is made in the form of gluing, including negative and positive lenses [SU 1800432 A1, 1993]. This eyepiece also has poor image quality and insufficient removal of the exit pupil.

The objective of the invention is to improve image quality while increasing the removal of the exit pupil.

The problem is achieved in that in an eyepiece with a remote exit pupil, consisting of a first component arranged in series on the optical axis, made in the form of a negative meniscus facing a space of objects, a second component made in the form of a positive lens, and a third component made in the form of a gluing containing a biconvex and biconcave lens, the lens on which the second component is made is plano-convex and faces the space with a flat surface objects, gluing, on which the third element is made, faces the exit pupil with the convex side, and the fourth component is introduced into the lens in the form of a plano-convex lens facing the exit pupil with a convex surface.

The invention is illustrated by drawings.

Figure 1 presents the optical scheme of the proposed eyepiece with a remote exit pupil,

figure 2 shows graphs of curvature and astigmatism,

figure 3 is a graph of relative distortion,

figure 4 is a graph of the frequency-contrast characteristics,

figure 5 - graphs of spherical aberrations for three values of the object; Y = 0 (point on the axis), Y = 3.2 mm (coordinate at the level of 0.7 field of view) and Y = 4.4 mm (coordinate for the edge of the field of view).

In Figs. 2, 3 and 5, the curves are presented for a wavelength of 546.1 nm. 5, the maximum scale of the ordinate axis is 20 arcminutes. The letters M and S in FIGS. 2 and 4 indicate a meridional (M) and sagittal (S) section.

The eyepiece with a remote exit pupil (figure 1) contains four components in the direction of the beam. The first component is made in the form of a negative meniscus 1, facing a concave surface to the space of objects. The second component is made in the form of a plano-convex lens 2, facing a flat surface to the space of objects, the third component is a gluing containing biconcave 3 and biconvex 4 lenses. This gluing is convex towards the exit pupil. The fourth component is made in the form of a plano-convex lens facing a convex surface to the exit pupil.

The eyepiece works as follows. Divergent beams of rays emanating from the points of a flat object located in the front focal plane of the eyepiece are converted into parallel ones and build an image of the plane of objects on the retina of the eye.

In accordance with the proposed technical solution, the eyepiece variant for the focal length f = 7 mm was calculated, while the exit pupil removal was 12 mm. The design parameters of the eyepiece lenses and the characteristics of the used glass brands of this lens are shown in the table.

Table Surface Radius of curvature Thickness Glass Diameter An object ∞ ∞ Nd Vd Aperture diaphragm ∞ 12 2 26.3 1.6 1.786 44.2 8.9 3 ∞ 0.2 8.9 four 6.56 3.3 1.786 44.2 8.9 5 -12.6 one 1.805 25.5 8.1 6 4.26 0.7 6.2 7 8.07 1.6 1.786 44.2 6.2 8 ∞ 0.2 6.2 9 6.56 1.5 1.786 44.2 5.9 10 11.7 2 5.4 Image plane ∞ 4.4

The proposed eyepiece operates in the spectral range of wavelengths - λ = 486.1 nm ... 656.3 nm.

As can be seen from the graphs of FIGS. curvature <5 / f diopters, distortion <2%) and high resolution (<1 mrad). The maximum value of spherical aberration in the eyepiece does not exceed 6-8 arc minutes.

Large removal of the exit pupil allows you to create a very short-focus eyepiece with high magnification (almost 40 times), for example, with a focus of 7 mm when removing 12 mm, which cannot be achieved in known eyepieces.

The high quality image of the eyepiece allows you to distinguish the smallest details in the image of the subject. Large removal of the exit pupil, at least 1.7 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 simultaneously examine the field of view of the eyepiece and service information. For this, it is not necessary to change the position of the observer’s head relative to the eyepiece, but rather to change the position of the observer’s eye. The field of view of the eyepiece is 2w> 35 °, which allows it to be used with standard monochrome and color LCD displays with a diagonal of 0.16 "to 1" and above. High technical characteristics allow the eyepiece to be used as a magnifier with modern LCD displays, the minimum pixel size of which is less than 10 um.

Claims (1)

An eyepiece with a remote exit pupil containing the first component mounted sequentially on the optical axis, made in the form of a negative meniscus facing the concave surface to the space of objects, the second component made in the form of a positive lens, and the third component made in the form of gluing containing biconvex and biconcave lenses, characterized in that the lens of which the second element is made is flat-convex and faces with a flat surface to the space of objects, gluing, from which n third element facing the convex surface to the exit pupil, and a fourth lens element is introduced in the form of a plano-convex lens facing the convex surface to the exit pupil.

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