A large-aperture target-viewing telescope optical system

Abstract

The present invention belongs to the technical field of telescope manufacturing, and discloses a large-aperture target observation telescope optical system, which is characterized in that: along the optical axis direction, from the object side to the image side, there are successively arranged an objective first lens, an objective second lens, a Porro first prism, a Porro second prism, a half pentaprism, a reticle, an eyepiece first lens, an eyepiece second lens, an eyepiece third lens, an eyepiece fourth lens, an eyepiece fifth lens, an eyepiece sixth lens, and an eyepiece seventh lens. This optical system can achieve continuous zooming from 25 times to 75 times, and has good imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of telescope manufacturing, and specifically to a large-aperture target observation telescope optical system. Background Technique

[0002] A target observation telescope is an optical instrument for long-distance observation and is widely used in environmental and military fields. Especially in the field of the wild environment, for the target observation telescope used by an operator, although high-magnification observation and aiming at a target are achieved, there are certain defects in the imaging quality. For example, during use, the imaging sharpness decreases, the distortion at the edge of the image plane is obvious, the image plane is blurred, and when the target observation telescope is used in cooperation with a digital camera to photograph birds, the quality of the photo is easily reduced after taking the photo. Summary of the Invention

[0003] The purpose of the present invention is to provide a large-aperture target observation telescope optical system to solve the problems raised in the above background technique.

[0004] To solve the above technical problems, the present invention provides the following technical solution: A large-aperture target observation telescope optical system, characterized in that: along the optical axis direction from the object side to the image side, an objective first lens, an objective second lens, a Porro first prism, a Porro second prism, a half pentaprism, a reticle, an eyepiece first lens, an eyepiece second lens, an eyepiece third lens, an eyepiece fourth lens, an eyepiece fifth lens, an eyepiece sixth lens, and an eyepiece seventh lens are sequentially arranged;

[0005] The objective first lens is a biconvex lens, the objective second lens is a meniscus lens with the concave surface facing the object side, the eyepiece first lens and the eyepiece second lens form a cemented lens, the eyepiece first lens is a meniscus lens with the concave surface facing the object side, the eyepiece second lens is a biconcave lens, the eyepiece third lens and the eyepiece fourth lens form a cemented lens, the eyepiece third lens is a plano-concave lens with the concave surface facing the image side, the eyepiece fourth lens is a biconvex lens, the eyepiece fifth lens is a biconvex lens, the eyepiece sixth lens and the eyepiece seventh lens form a cemented lens, the eyepiece sixth lens is a biconvex lens, the eyepiece seventh lens is a biconcave lens, and only the above 9 lenses of the optical system have optical power.

[0006] As a preferred technical solution, the object-side curvature radius of the objective first lens is 297.3 mm, the image-side curvature radius is 297.3 mm, the central thickness is 12.5 mm, the material is made of glass H-FK61, and the contour diameter is 107 mm; the object-side curvature radius of the objective second lens is -282.8 mm, the image-side curvature radius is 888.9 mm, the central thickness is 6 mm, the material is made of glass H-TF5, and the contour diameter is 107 mm;

[0007] The object-side curvature radius of the first eyepiece lens is -27.27 mm, the image-side curvature radius is 12.52 mm, the central thickness is 4.8 mm, the material is glass H-ZF4, and the contour diameter is 19 mm; the object-side curvature radius of the second eyepiece lens is -12.52 mm, the image-side curvature radius is -27.27 mm, the central thickness is 1.6 mm, the material is glass H-ZK9, and the contour diameter is 19 mm; the object-side of the third eyepiece lens is a plane, the image-side curvature radius is -34.26 mm, the central thickness is 2.4 mm, the material is glass H-ZF2, and the contour diameter is 32 mm; the object-side curvature radius of the fourth eyepiece lens is 34.26 mm, the image-side curvature radius is 34.26 mm, the central thickness is 10.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the fifth eyepiece lens is 58.8 mm, the image-side curvature radius is 58.8 mm, the central thickness is 7.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the sixth eyepiece lens is 30.6 mm, the image-side curvature radius is 30.6 mm, the central thickness is 8 mm, the material is glass H-ZK9, and the contour diameter is 28 mm; the object-side curvature radius of the seventh eyepiece lens is -30.6 mm, the image-side curvature radius is -305.4 mm, the central thickness is 2.1 mm, the material is glass H-ZF4, and the contour diameter is 28 mm, where a positive curvature radius indicates a convex surface and a negative curvature radius indicates a concave surface.

[0008] As a preferred technical solution, the distance between the first objective lens and the second objective lens along the optical axis direction is 4.45 mm, the distance between the second objective lens and the first Porro prism is 408.5 mm, the distance between the first Porro prism and the second Porro prism is 6 mm, the distance between the second Porro prism and the half pentaprism is 12 mm, the distance between the half pentaprism and the reticle is 2 mm, the distance between the reticle and the first eyepiece lens is 9.9 - 19 mm, the distance between the second eyepiece lens and the third eyepiece lens is 11.76 - 49.35 mm, the distance between the fourth eyepiece lens and the fifth eyepiece lens is 0.3 mm, and the distance between the fifth eyepiece lens and the sixth eyepiece lens is 2.02 - 30.42 mm.

[0009] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0010] The magnification of the telescope optical system of this application can be continuously variable from 25 times to 75 times. The first objective lens and the second objective lens form an objective lens group, the focal length of the objective lens group is 560.1 mm, and the nearest focusing distance is 8.5 m; when the magnification is 25 times, the focal length of the eyepiece is 22.7 mm, the overall field of view of the machine is 1.57°, the exit pupil diameter is 4.25 mm, the exit pupil distance is 19.7 mm, the twilight index is 50.93, and the relative brightness is 18.06.

[0011] When the magnification is 75 times, the focal length of the eyepiece is 7.6 mm, the overall field of view is 0.88°, the exit pupil diameter is 1.42 mm, the exit pupil distance is 17.7 mm, the twilight index is 87.97, and the relative brightness is 2.02. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0013] Figure 1 is a schematic diagram of the optical system of the present invention;

[0014] Figure 2 is the field curvature distortion diagram of the present invention with a magnification of 25 times;

[0015] Figure 3 is the spot diagram of the present invention with a magnification of 25 times;

[0016] Figure 4 is the grid distortion diagram of the present invention with a magnification of 25 times;

[0017] Figure 5 is the field curvature distortion diagram of the present invention with a magnification of 75 times;

[0018] Figure 6 is the spot diagram of the present invention with a magnification of 75 times;

[0019] Figure 7 is the grid distortion diagram of the present invention with a magnification of 75 times. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0021] As shown in the attached Figure 1-4 figures, the present invention provides the following technical solution: An optical system for a large-aperture target observation telescope, characterized in that: along the optical axis direction from the object side to the image side, there are successively arranged an objective lens first lens 1, an objective lens second lens 2, a Porro first prism 3, a Porro second prism 4, a half pentaprism 5, a reticle 6, an eyepiece first lens 7, an eyepiece second lens 8, an eyepiece third lens 9, an eyepiece fourth lens 10, an eyepiece fifth lens 11, an eyepiece sixth lens 12, and an eyepiece seventh lens 13;

[0022] The first objective lens 1 is a biconvex lens, and the second objective lens 2 is a meniscus lens with the concave surface facing the object side. The first eyepiece lens 7 and the second eyepiece lens 8 form a cemented lens. The first eyepiece lens 7 is a meniscus lens with the concave surface facing the object side, and the second eyepiece lens 8 is a biconcave lens. The third eyepiece lens 9 and the fourth eyepiece lens 10 form a cemented lens. The third eyepiece lens 9 is a plano-concave lens with the concave surface facing the image side, and the fourth eyepiece lens 10 is a biconvex lens. The fifth eyepiece lens 11 is a biconvex lens. The sixth eyepiece lens 12 and the seventh eyepiece lens 13 form a cemented lens. The sixth eyepiece lens 12 is a biconvex lens, and the seventh eyepiece lens 13 is a biconcave lens. Only the above 9 lenses in the optical system have optical power.

[0023] The object-side curvature radius of the first objective lens 1 is 297.3 mm, the image-side curvature radius is 297.3 mm, the central thickness is 12.5 mm, the material is glass H-FK61, and the contour diameter is 107 mm; the object-side curvature radius of the second objective lens 2 is -282.8 mm, the image-side curvature radius is 888.9 mm, the central thickness is 6 mm, the material is glass H-TF5, and the contour diameter is 107 mm;

[0024] The object-side curvature radius of the first eyepiece lens 7 is -27.27 mm, the image-side curvature radius is 12.52 mm, the central thickness is 4.8 mm, the material is glass H-ZF4, and the contour diameter is 19 mm; the object-side curvature radius of the second eyepiece lens 8 is -12.52 mm, the image-side curvature radius is -27.27 mm, the central thickness is 1.6 mm, the material is glass H-ZK9, and the contour diameter is 19 mm; the object side of the third eyepiece lens 9 is a plane, the image-side curvature radius is -34.26 mm, the central thickness is 2.4 mm, the material is glass H-ZF2, and the contour diameter is 32 mm; the object-side curvature radius of the fourth eyepiece lens 10 is 34.26 mm, the image-side curvature radius is 34.26 mm, the central thickness is 10.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the fifth eyepiece lens 11 is 58.8 mm, the image-side curvature radius is 58.8 mm, the central thickness is 7.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the sixth eyepiece lens 12 is 30.6 mm, the image-side curvature radius is 30.6 mm, the central thickness is 8 mm, the material is glass H-ZK9, and the contour diameter is 28 mm; the object-side curvature radius of the seventh eyepiece lens 13 is -30.6 mm, the image-side curvature radius is -305.4 mm, the central thickness is 2.1 mm, the material is glass H-ZF4, and the contour diameter is 28 mm. A positive curvature radius indicates a convex surface, and a negative curvature radius indicates a concave surface.

[0025] The distance between the first objective lens 1 and the second objective lens 2 along the optical axis is 4.45 mm, the distance between the second objective lens 2 and the first Porro prism 3 is 408.5 mm, the distance between the first Porro prism 3 and the second Porro prism 4 is 6 mm, the distance between the second Porro prism 4 and the half pentaprism 5 is 12 mm, the distance between the half pentaprism 5 and the reticle 6 is 2 mm, the distance between the reticle 6 and the first eyepiece lens 7 is 19 mm, the distance between the second eyepiece lens 8 and the third eyepiece lens 9 is 11.76 mm, the distance between the fourth eyepiece lens 10 and the fifth eyepiece lens 11 is 0.3 mm, and the distance between the fifth eyepiece lens 11 and the sixth eyepiece lens 12 is 30.42 mm.

[0026] The magnification of the above parameters corresponding to the optical system is 25 times, the focal length of the eyepiece is 22.7 mm, the overall field of view is 1.57°, the exit pupil diameter is 4.25 mm, the exit pupil distance is 19.7 mm, the twilight index is 50.93, and the relative brightness is 18.06. Embodiment

[0027] As shown in the attached Figure 1 , Figure 5-7 As shown, the present invention provides the following technical solution: a large-aperture target observation mirror optical system, characterized in that: along the optical axis direction, from the object side to the image side, there are sequentially arranged a first objective lens 1, a second objective lens 2, a first Porro prism 3, a second Porro prism 4, a half pentaprism 5, a reticle 6, a first eyepiece lens 7, a second eyepiece lens 8, a third eyepiece lens 9, a fourth eyepiece lens 10, a fifth eyepiece lens 11, and a sixth eyepiece lens 12, and a seventh eyepiece lens 13;

[0028] The first objective lens 1 is a biconvex lens, the second objective lens 2 is a meniscus lens with the concave surface facing the object side, the first eyepiece lens 7 and the second eyepiece lens 8 form a cemented lens, the first eyepiece lens 7 is a meniscus lens with the concave surface facing the object side, the second eyepiece lens 8 is a biconcave lens, the third eyepiece lens 9 and the fourth eyepiece lens 10 form a cemented lens, the third eyepiece lens 9 is a plano-concave lens with the concave surface facing the image side, the fourth eyepiece lens 10 is a biconvex lens, the fifth eyepiece lens 11 is a biconvex lens, the sixth eyepiece lens 12 and the seventh eyepiece lens 13 form a cemented lens, the sixth eyepiece lens 12 is a biconvex lens, and the seventh eyepiece lens 13 is a biconcave lens. Only the above 9 lenses of the optical system have optical power.

[0029] As a preferred technical solution, the object-side curvature radius of the first lens 1 of the objective lens is 297.3 mm, the image-side curvature radius is 297.3 mm, the central thickness is 12.5 mm, the material is glass H-FK61, and the contour diameter is 107 mm; the object-side curvature radius of the second lens 2 of the objective lens is -282.8 mm, the image-side curvature radius is 888.9 mm, the central thickness is 6 mm, the material is glass H-TF5, and the contour diameter is 107 mm;

[0030] The object-side curvature radius of the first lens 7 of the eyepiece is -27.27 mm, the image-side curvature radius is 12.52 mm, the central thickness is 4.8 mm, the material is glass H-ZF4, and the contour diameter is 19 mm; the object-side curvature radius of the second lens 8 of the eyepiece is -12.52 mm, the image-side curvature radius is -27.27 mm, the central thickness is 1.6 mm, the material is glass H-ZK9, and the contour diameter is 19 mm; the object-side of the third lens 9 of the eyepiece is a plane, the image-side curvature radius is -34.26 mm, the central thickness is 2.4 mm, the material is glass H-ZF2, and the contour diameter is 32 mm; the object-side curvature radius of the fourth lens 10 of the eyepiece is 34.26 mm, the image-side curvature radius is 34.26 mm, the central thickness is 10.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the fifth lens 11 of the eyepiece is 58.8 mm, the image-side curvature radius is 58.8 mm, the central thickness is 7.5 mm, the material is glass H-ZK3, and the contour diameter is 32 mm; the object-side curvature radius of the sixth lens 12 of the eyepiece is 30.6 mm, the image-side curvature radius is 30.6 mm, the central thickness is 8 mm, the material is glass H-ZK9, and the contour diameter is 28 mm; the object-side curvature radius of the seventh lens 13 of the eyepiece is -30.6 mm, the image-side curvature radius is -305.4 mm, the central thickness is 2.1 mm, the material is glass H-ZF4, and the contour diameter is 28 mm.

[0031] As a preferred technical solution, along the optical axis direction, the distance between the first lens 1 and the second lens 2 of the objective lens is 4.45 mm, the distance between the second lens 2 of the objective lens and the first Porro prism 3 is 408.5 mm, the distance between the first Porro prism 3 and the second Porro prism 4 is 6 mm, the distance between the second Porro prism 4 and the half pentaprism 5 is 12 mm, the distance between the half pentaprism 5 and the reticle 6 is 2 mm, the distance between the reticle 6 and the first lens 7 of the eyepiece is 9.9 mm, the distance between the second lens 8 and the third lens 9 of the eyepiece is 49.35 mm, the distance between the fourth lens 10 and the fifth lens 11 of the eyepiece is 0.3 mm, and the distance between the fifth lens 11 and the sixth lens 12 of the eyepiece is 2.02 mm.

[0032] The magnification of the above parameters corresponding to the optical system is 75 times, the focal length of the eyepiece is 7.6 mm, the overall field of view of the whole machine is 0.88°, the exit pupil diameter is 1.42 mm, the exit pupil distance is 17.7 mm, the twilight index is 87.97, and the relative brightness is 2.02.

[0033] During the process of adjusting the optical system of the telescope from 25 times to 75 times, the cemented lens composed of the first eyepiece lens and the second eyepiece lens moves towards the object side, and the third eyepiece lens, the fourth eyepiece lens and the fifth eyepiece lens move as a whole towards the object side. Moreover, in order to eliminate chromatic aberration, in this application, an ED film is coated on the object side of the first objective lens and the second objective lens.

[0034] Appendix Figure 2 and Appendix Figure 5 are the field curvature and distortion diagrams of 25 times and 75 times of this application. The analysis of the field curvature and distortion diagram is an important tool for evaluating the imaging quality of the optical system. It reveals the influence of field curvature and distortion on the imaging effect, and is also called field curvature. It describes that after a flat object passes through the lens system, the formed clear image points are not on a plane, but a curved surface. Distortion reflects the similarity degree between the object and the image, including types such as barrel distortion and pincushion distortion.

[0035] We can see through Appendix Figure 2 that when the magnification of the telescope optical system is 25 times, Figure 2 in the field curvature curve, the wavelengths are 0.486 um, 0.588 um, 0.656 um, S represents the arc vector, and T represents the meridian quantity. From the field curvature curve, we can see that the field curvature of this application is very small, both the edge and the center are relatively clear, the image quality is good, and the maximum field of view is 1.57°; we can see through Appendix Figure 5 that when the magnification of the telescope optical system is 75 times, Figure 5 in the field curvature curve, the wavelengths are 0.486 um, 0.588 um, 0.656 um, S represents the arc vector, and T represents the meridian quantity. From the field curvature curve, we can see that the field curvature of this application is very small, both the edge and the center are relatively clear, the image quality is good, and the maximum field of view is 0.88°; we can easily find that the field of view is continuously shrinking during the process of magnification from 25 to 75.

[0036] Appendix Figure 3 and Appendix Figure 6 are the spot diagrams of this application. The distribution of points in the spot diagram should be uniform and dense, without obvious outliers or off - points. The more average the data distribution is, the more stable the imaging quality is. The energy of the spot diagram of the optical system in this application is relatively concentrated and the imaging is relatively clear. If using Figure 3 and Figure 6When making a comparison, it is not difficult to find that when the magnification is 75 times, the imaging quality deteriorates. Especially when the field of view is the maximum field of view of 0.88°, the point spread forms an elongated elliptical distribution.

[0037] Appendix Figure 4 and Appendix Figure 7 are the grid distortion diagrams of this application, as shown in Appendix Figure 4 : the maximum distortion at the edge of the image plane is 2% at a magnification of 25 times; as shown in Appendix Figure 7 : the maximum distortion at the edge of the image plane is 13% at a magnification of 75 times. From Appendix Figure 4 and Appendix Figure 7 we can easily find that there is almost no distortion at the imaging edge at a magnification of 25 times, but when the magnification reaches 75 times, the distortion at the edge of the image plane becomes very obvious.

[0038] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A large-aperture target viewing mirror optical system, characterized in that: An objective lens first lens (1), an objective lens second lens (2), a Porro first prism (3), a Porro second prism (4), a half pentaprism (5), a graticule (6), an eyepiece first lens (7), an eyepiece second lens (8), an eyepiece third lens (9), an eyepiece fourth lens (10), an eyepiece fifth lens (11), an eyepiece sixth lens (12), and an eyepiece seventh lens (13) are sequentially arranged along the optical axis from the object side to the image side; The first lens (1) of the objective lens is a biconvex lens, the second lens (2) of the objective lens is a concave-convex lens, with the concave surface facing the object side, the first lens (7) of the eyepiece and the second lens (8) of the eyepiece form a cemented lens, the first lens (7) of the eyepiece is a concave-convex lens, with the concave surface facing the object side, the second lens (8) of the eyepiece is a biconcave lens, the third lens (9) of the eyepiece and the fourth lens (10) of the eyepiece form a cemented lens, the third lens (9) of the eyepiece is a plano-concave lens, with the concave surface facing the image side, the fourth lens (10) of the eyepiece is a biconvex lens, the fifth lens (11) of the eyepiece is a biconvex lens, the sixth lens (12) of the eyepiece and the seventh lens (13) of the eyepiece form a cemented lens, the sixth lens (12) of the eyepiece is a biconvex lens, and the seventh lens (13) of the eyepiece is a biconcave lens, and the optical system has only the above 9 lenses having optical power; The first lens (1) of the objective lens has an object side curvature radius of 297.3 mm, an image side curvature radius of 297.3 mm, a center thickness of 12.5 mm, is made of glass H-FK61, and has a profile diameter of 107 mm; the second lens (2) of the objective lens has an object side curvature radius of -282.8 mm, an image side curvature radius of 888.9 mm, a center thickness of 6 mm, is made of glass H-TF5, and has a profile diameter of 107 mm; The first lens (7) of the eyepiece has a curvature radius of -27.27 mm on the object side, a curvature radius of 12.52 mm on the image side, a center thickness of 4.8 mm, and is made of glass H-ZF4 with a profile diameter of 19 mm; the second lens (8) of the eyepiece has a curvature radius of -12.52 mm on the object side, a curvature radius of -27.27 mm on the image side, a center thickness of 1.6 mm, and is made of glass H-ZK9 with a profile diameter of 19 mm; the third lens (9) of the eyepiece has a flat object side, a curvature radius of -34.26 mm on the image side, a center thickness of 2.4 mm, and is made of glass H-ZF2 with a profile diameter of 32 mm; the fourth lens (10) of the eyepiece has a curvature radius of 34.26 mm on the object side, a curvature radius of 34.26 mm on the image side, and a center thickness of 10.5 mm , the material is glass H-ZK3, and the outline diameter is 32mm; the object side curvature radius of the eyepiece fifth lens (11) is 58.8mm, the image side curvature radius is 58.8mm, the center thickness is 7.5mm, the material is glass H-ZK3, and the outline diameter is 32mm; the object side curvature radius of the eyepiece sixth lens (12) is 30.6mm, the image side curvature radius is 30.6mm, the center thickness is 8mm, the material is glass H-ZK9, and the outline diameter is 28mm; the object side curvature radius of the eyepiece seventh lens (13) is -30.6mm, the image side curvature radius is -305.4mm, the center thickness is 2.1mm, the material is glass H-ZF4, and the outline diameter is 28mm, wherein a positive number for the curvature radius indicates a convex surface, and a negative number for the curvature radius indicates a concave surface.

2. The large-aperture target viewing scope optical system according to claim 1, characterized in that: Along the optical axis direction, the distance between the first lens (1) of the objective lens and the second lens (2) of the objective lens is 4.45 mm, the distance between the second lens (2) of the objective lens and the first Porro prism (3) is 408.5 mm, the distance between the first Porro prism (3) and the second Porro prism (4) is 6 mm, the distance between the second Porro prism (4) and the semi-penta prism (5) is 12 mm, the distance between the semi-penta prism (5) and the graticule (6) is 2 mm, the distance between the graticule (6) and the first lens (7) of the eyepiece is 9.9-19 mm, the distance between the second lens (8) of the eyepiece and the third lens (9) of the eyepiece is 11.76-49.35 mm, the distance between the fourth lens (10) of the eyepiece and the fifth lens (11) of the eyepiece is 0.3 mm, and the distance between the fifth lens (11) of the eyepiece and the sixth lens (12) of the eyepiece is 2.02-30.42 mm.

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