Optical system of small-caliber large field-of-view telescope

Abstract

The application belongs to the technical field of telescope manufacturing, and discloses a small-caliber large-view-field telescope optical system, characterized in that: from the object side to the image side along the optical axis direction, an objective lens first lens, an objective lens second lens, an objective lens third lens, a focusing mirror, a half-pentagonal prism, a ridge prism, an eyepiece first lens, an eyepiece second lens, an eyepiece third lens, an eyepiece fourth lens, an eyepiece fifth lens and an eyepiece sixth lens are sequentially arranged; and the optical system realizes a large view field of 6.7° under 10 times.

Description

Technical Field

[0001] This invention relates to the field of telescope manufacturing technology, specifically to an optical system for a small-aperture, large-field-of-view telescope. Background Technology

[0002] A telescope is a device for observing distant objects. The development of telescopes has a long history. Modern telescopes typically use Porro prisms and roof prisms. Telescopes using Porro prisms have a simple structure and high reliability, but the telescope body is relatively large and inconvenient to carry. With the development of roof prisms, the size of telescopes has been significantly reduced, but the structure has become more complex, and the requirements for manufacturing precision have also increased accordingly. There are many small-aperture telescopes in the current technology, but due to unreasonable optical design, the field of view of the entire telescope is relatively small and the distortion is relatively large. Summary of the Invention

[0003] The purpose of this invention is to provide an optical system for a small-aperture, large-field-of-view telescope to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an optical system for a small-aperture, large-field-of-view telescope, characterized in that: along the optical axis from the object side to the image side, a first objective lens, a second objective lens, a third objective lens, a focusing lens, a semi-pentagonal prism, a roof prism, a first eyepiece lens, a second eyepiece lens, a third eyepiece lens, a fourth eyepiece lens, a fifth eyepiece lens, and a sixth eyepiece lens are arranged sequentially.

[0005] The first objective lens is a plano-convex lens with its convex surface facing the object side. The second and third objective lenses form a cemented lens. The second objective lens is a biconvex lens, and the third objective lens is a biconcave lens. The focusing lens is a concave-convex lens with its convex surface facing the object side. The first and second eyepiece lenses form a cemented lens. The first eyepiece lens is a biconcave lens, and the second eyepiece lens is a concave-convex lens with its convex surface facing the object side. The third eyepiece lens is a concave-convex lens with its concave surface facing the object side. The fourth and fifth eyepiece lenses form a cemented lens. The fourth eyepiece lens is a concave-convex lens with its convex surface facing the object side. The fifth eyepiece lens is a biconvex lens. The sixth eyepiece lens is a concave-convex lens with its convex surface facing the object side. Only these 10 lenses in the optical system have optical power.

[0006] As a preferred technical solution, the first objective lens has an object-side radius of curvature of 54.4 mm, an image-side plane, a center thickness of 3.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the second objective lens has an object-side radius of curvature of 40.77 mm, an image-side radius of curvature of 156 mm, a center thickness of 4.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the third objective lens has an object-side radius of curvature of -156 mm, an image-side radius of curvature of -156 mm, a center thickness of 2 mm, is made of H-ZBaF21 glass, and has an outline diameter of 27 mm; the focusing lens has an object-side radius of curvature of 66.68 mm, an image-side radius of curvature of -24.5 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm.

[0007] The first eyepiece lens has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm. The second eyepiece lens has an object-side radius of curvature of 11.69 mm, an image-side radius of curvature of -18.27 mm, a center thickness of 3 mm, is made of H-ZF4 glass, and has an outline diameter of 15 mm. The third eyepiece lens has an object-side radius of curvature of -42.8 mm, an image-side radius of curvature of 16.46 mm, a center thickness of 4.9 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The fourth eyepiece lens has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The first eyepiece has an object-side radius of curvature of 142.36 mm, an image-side radius of curvature of -19.75 mm, a center thickness of 2 mm, is made of H-ZF62 glass, and has an outline diameter of 23 mm. The second eyepiece has an object-side radius of curvature of 19.75 mm, an image-side radius of curvature of 32.52 mm, a center thickness of 7 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The third eyepiece has an object-side radius of curvature of 17.28 mm, an image-side radius of curvature of 246 mm, a center thickness of 5.5 mm, is made of H-ZK3 glass, and has an outline diameter of 22.5 mm. Positive radii of curvature indicate a convex surface, and negative radii of curvature indicate 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 is 0.4 mm, the distance between the third objective lens and the focusing lens is 21.5 mm, the distance between the focusing lens and the semi-pentagonal prism is 15.5 mm, the distance between the roof prism and the first eyepiece lens is 5 mm, the distance between the second eyepiece lens and the third eyepiece lens is 8.98 mm, the distance between the third eyepiece lens and the fourth eyepiece lens is 0.25 mm, and the distance between the fifth eyepiece lens and the sixth eyepiece lens is 0.25 mm.

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

[0010] The first objective lens, second objective lens, third objective lens, and focusing lens of this application constitute an objective lens group with a focal length of 117.1 mm. The focusing lens can move back and forth to adjust the focus. The side thickness of the semi-pentaprism and the roof prism is 12.5 mm. The first eyepiece lens to the sixth eyepiece lens constitute an eyepiece group with a focal length of 12 mm. The system can be made into binoculars or monoculars.

[0011] The telescope's optical system has a magnification of 10x, a field of view of 6.7°, an exit pupil diameter of 2.55mm, an exit pupil distance of 16mm, a minimum focusing distance of 1m, a twilight index of 15.81, a relative brightness of 6.5, and a total length of 103.4mm. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

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

[0014] Figure 2 This is the field distortion diagram of the present invention;

[0015] Figure 3 This is a dot diagram of the present invention;

[0016] Figure 4 This is the mesh distortion diagram of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] As attached Figure 1-4 As shown, the present invention provides the following technical solution: an optical system for a small-aperture, large-field-of-view telescope, characterized in that: along the optical axis from the object side to the image side, there are arranged in sequence the following components: objective lens 1, objective lens 2, objective lens 3, focusing lens 4, semi-pentagonal prism 5, roof prism 6, eyepiece lens 7, eyepiece lens 8, eyepiece lens 9, eyepiece lens 4, eyepiece lens 10, eyepiece lens 5, and eyepiece lens 6;

[0019] The first objective lens 1 is a plano-convex lens with its convex surface facing the object side. The second objective lens 2 and the third objective lens 3 form a cemented lens. The second objective lens 2 is a biconvex lens, and the third objective lens 3 is a biconcave lens. The focusing lens 4 is a concave-convex lens with its convex 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 biconcave lens, and the second eyepiece lens 8 is a concave-convex lens with its convex surface facing the object side. The third eyepiece lens 9 is a concave-convex lens with its concave surface facing the object side. The fourth eyepiece lens 10 and the fifth eyepiece lens 11 form a cemented lens. The fourth eyepiece lens 10 is a concave-convex lens with its convex surface facing the object side, and the fifth eyepiece lens 11 is a biconvex lens. The sixth eyepiece lens 12 is a concave-convex lens with its convex surface facing the object side. Only the above 10 lenses in the optical system have optical power.

[0020] As a preferred technical solution, the first objective lens 1 has an object-side radius of curvature of 54.4 mm, an image-side plane, a center thickness of 3.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the second objective lens 2 has an object-side radius of curvature of 40.77 mm, an image-side radius of curvature of 156 mm, a center thickness of 4.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the third objective lens 3 has an object-side radius of curvature of -156 mm, an image-side radius of curvature of -156 mm, a center thickness of 2 mm, is made of H-ZBaF21 glass, and has an outline diameter of 27 mm; the focusing lens 4 has an object-side radius of curvature of 66.68 mm, an image-side radius of curvature of -24.5 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm;

[0021] The first eyepiece lens 7 has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm. The second eyepiece lens 8 has an object-side radius of curvature of 11.69 mm, an image-side radius of curvature of -18.27 mm, a center thickness of 3 mm, is made of H-ZF4 glass, and has an outline diameter of 15 mm. The third eyepiece lens 9 has an object-side radius of curvature of -42.8 mm, an image-side radius of curvature of 16.46 mm, a center thickness of 4.9 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The fourth eyepiece lens 10 has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The first eyepiece has an object-side radius of curvature of 142.36 mm, an image-side radius of curvature of -19.75 mm, a center thickness of 2 mm, is made of H-ZF62 glass, and has an outline diameter of 23 mm. The second eyepiece has an object-side radius of curvature of 19.75 mm, an image-side radius of curvature of 32.52 mm, a center thickness of 7 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm. The third eyepiece has an object-side radius of curvature of 17.28 mm, an image-side radius of curvature of 246 mm, a center thickness of 5.5 mm, is made of H-ZK3 glass, and has an outline diameter of 22.5 mm. Positive radii of curvature indicate a convex surface, and negative radii of curvature indicate a concave surface.

[0022] As a preferred technical solution, the distance between the first objective lens 1 and the second objective lens 2 along the optical axis is 0.4 mm, the distance between the third objective lens 3 and the focusing lens 4 is 21.5 mm, the distance between the focusing lens 4 and the semi-pentagonal prism 5 is 15.5 mm, the distance between the roof prism 6 and the first eyepiece lens 7 is 5 mm, the distance between the second eyepiece lens 8 and the third eyepiece lens 9 is 8.98 mm, the distance between the third eyepiece lens 9 and the fourth eyepiece lens 10 is 0.25 mm, and the distance between the fifth eyepiece lens 11 and the sixth eyepiece lens 12 is 0.25 mm.

[0023] The objective lens group in this application consists of a first objective lens 1, a second objective lens 2, a third objective lens 3, and a focusing lens 4. The focal length of the objective lens group is 117.1 mm. The focusing lens can move back and forth to adjust the focus. The side thickness of the semi-pentaprism 5 and the roof prism 6 is 12.5 mm. The eyepiece group consists of the first eyepiece lens 7 to the sixth eyepiece lens 12. The focal length of the eyepiece group is 12 mm. The system can be made into binoculars or monoculars. The optical system of the telescope has a magnification of 10x, a field of view of 6.7°, an exit pupil diameter of 2.55 mm, an exit pupil distance of 16 mm, a minimum focusing distance of 1 m, a twilight index of 15.81, and a relative brightness of 6.5.

[0024] Appendix Figure 2This is the field curvature distortion diagram of this application. Field curvature distortion diagram analysis is an important tool for evaluating the imaging quality of optical systems. It reveals the influence of field curvature and distortion on the imaging effect. Also known as image field curvature, it describes how the sharp image point formed after a planar object passes through a lens system is not on a plane, but on a curved surface. Distortion reflects the similarity between the object and the image, including types such as barrel distortion and pincushion distortion.

[0025] We attach Figure 2 It can be seen that when the telescope's optical system has a magnification of 10x, Figure 2 In the field curvature curves, the wavelengths are 0.486um, 0.588um, and 0.656um, where S represents the arc vector and T represents the meridional quantity. From the field curvature curves, we can see that the field curvature of this application is very small, and the edges and center are relatively clear, resulting in good image quality. The maximum field of view is 6.7°.

[0026] Appendix Figure 3 This is the dot plot of this application. The distribution of points in the dot plot should be uniform and dense, with no obvious outliers or isolated points. The more uniform the data distribution, the more stable the imaging quality. The dot plot of the optical system in this application has relatively concentrated energy and clear imaging.

[0027] Appendix Figure 4 This is the mesh distortion map of this application, provided by Appendix Figure 4 The data shows that at a magnification of 10x, the maximum distortion at the edge of the image plane is 4%.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An optical system for a small-aperture, large-field-of-view telescope, characterized by: Along the optical axis from the object side to the image side are arranged the following lenses in sequence: objective lens 1 (1), objective lens 2 (2), objective lens 3 (3), focusing lens (4), semi-pentagonal prism (5), roof prism (6), eyepiece 1 (7), eyepiece 2 (8), eyepiece 3 (9), eyepiece 4 (10), eyepiece 5 (11), and eyepiece 6 (12). The first objective lens (1) is a plano-convex lens with its convex surface facing the object side. The second objective lens (2) and the third objective lens (3) form a cemented lens. The second objective lens (2) is a biconvex lens, and the third objective lens (3) is a biconcave lens. The focusing lens (4) is a concave-convex lens with its convex 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 biconcave lens, and the second eyepiece lens (8) is a concave-convex lens with its convex surface facing the object side. The third eyepiece lens (9) is a concave-convex lens with its concave surface facing the object side. The fourth eyepiece lens (10) and the fifth eyepiece lens (11) form a cemented lens. The fourth eyepiece lens (10) is a concave-convex lens with its convex surface facing the object side. The fifth eyepiece lens (11) is a biconvex lens. The sixth eyepiece lens (12) is a concave-convex lens with its convex surface facing the object side. Only the above 10 lenses in the optical system have optical power. The objective lens (1) has an object-side radius of curvature of 54.4 mm, an image-side plane, a center thickness of 3.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the objective lens (2) has an object-side radius of curvature of 40.77 mm, an image-side radius of curvature of 156 mm, a center thickness of 4.5 mm, is made of H-FK61 glass, and has an outline diameter of 27 mm; the objective lens (3) has an object-side radius of curvature of -156 mm, an image-side radius of curvature of -156 mm, a center thickness of 2 mm, is made of H-ZBaF21 glass, and has an outline diameter of 27 mm; the focusing lens (4) has an object-side radius of curvature of 66.68 mm, an image-side radius of curvature of -24.5 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm; The first eyepiece lens (7) has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 mm, is made of H-K9L glass, and has an outline diameter of 15 mm; the second eyepiece lens (8) has an object-side radius of curvature of 11.69 mm, an image-side radius of curvature of -18.27 mm, a center thickness of 3 mm, is made of H-ZF4 glass, and has an outline diameter of 15 mm; the third eyepiece lens (9) has an object-side radius of curvature of -42.8 mm, an image-side radius of curvature of 16.46 mm, a center thickness of 4.9 mm, is made of H-LaK2A glass, and has an outline diameter of 23 mm; the fourth eyepiece lens (10) has an object-side radius of curvature of -31.7 mm, an image-side radius of curvature of -11.69 mm, a center thickness of 1.3 ...K9L glass, and has an outline diameter of 15 mm; The radius is 142.36mm, the image-side radius of curvature is -19.75mm, the center thickness is 2mm, the material is glass H-ZF62, and the outline diameter is 23mm; the fifth eyepiece (11) has an object-side radius of curvature of 19.75mm, an image-side radius of curvature of 32.52mm, a center thickness of 7mm, the material is glass H-LaK2A, and the outline diameter is 23mm; the sixth eyepiece (12) has an object-side radius of curvature of 17.28mm, an image-side radius of curvature of 246mm, a center thickness of 5.5mm, the material is glass H-ZK3, and the outline diameter is 22.5mm, where a positive radius of curvature indicates a convex surface, and a negative radius of curvature indicates a concave surface.

2. The optical system for a small-aperture, large-field-of-view telescope according to claim 1, characterized in that: Along the optical axis, the distance between the first objective lens (1) and the second objective lens (2) is 0.4 mm, the distance between the third objective lens (3) and the focusing lens (4) is 21.5 mm, the distance between the focusing lens (4) and the semi-pentagonal prism (5) is 15.5 mm, the distance between the roof prism (6) and the first eyepiece lens (7) is 5 mm, the distance between the second eyepiece lens (8) and the third eyepiece lens (9) is 8.98 mm, the distance between the third eyepiece lens (9) and the fourth eyepiece lens (10) is 0.25 mm, and the distance between the fifth eyepiece lens (11) and the sixth eyepiece lens (12) is 0.25 mm.

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