Optical system for a long eye relief binocular

Abstract

The application belongs to the technical field of telescope manufacturing, and discloses a long eye relief binocular telescope optical system, which is 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 lens, a half pentagonal prism, a roof prism, an isosceles prism, an eyepiece first lens, an eyepiece second lens, an eyepiece third lens, an eyepiece fourth lens and an eyepiece fifth lens are sequentially arranged; the exit pupil distance is 18.6mm under 12 times magnification, and the exit pupil distance is 14.1mm under 16 times magnification.

Description

Technical Field

[0001] This invention relates to the field of telescope manufacturing technology, specifically to an optical system for binoculars with a long external pupil distance. Background Technology

[0002] Binoculars are a common piece of outdoor equipment, and the exit pupil distance is a very important parameter. Currently, most binoculars with magnification of 12x or higher have an exit pupil distance of less than 14mm. Summary of the Invention

[0003] The purpose of this invention is to provide an optical system for binoculars with a long exit pupil distance 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 binoculars with a long exit pupil distance, characterized in that: along the optical axis from the object side to the image side, the following are arranged sequentially: a first objective lens, a second objective lens, a third objective lens, a focusing lens, a semi-pentaprism, a roof prism, an oblique prism, a first eyepiece lens, a second eyepiece lens, a third eyepiece lens, a fourth eyepiece lens, and a fifth eyepiece lens. The first objective lens is a biconvex lens; the second and third objective lenses are cemented lenses; the second objective lens is a biconvex lens; 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 are close together at their edges; the first eyepiece lens is a biconcave lens; the second eyepiece lens is a concave-convex lens with its concave surface facing the object side; the third and fourth eyepiece lenses form a cemented lens; the third eyepiece lens is a biconvex lens; the fourth eyepiece lens is a concave-convex lens with its concave surface facing the object side; and the fifth eyepiece lens is a biconvex lens. Only these nine lenses in the optical system possess optical power. The first objective lens has an object-side radius of curvature of +139.9 mm, an image-side radius of curvature of +263.6 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm. The second objective lens has an object-side radius of curvature of +77.6 mm, an image-side radius of curvature of +155.1 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm. The third objective lens has an object-side radius of curvature of -155.1 mm, an image-side radius of curvature of +139.9 mm, an image-side radius of curvature of +263.6 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm. The object-side radius of curvature is -155.1 mm, the center thickness is 2.5 mm, the material is H-BAF5 glass, and the diameter is 40.5 mm; the focusing lens has an object-side radius of curvature of +113.59 mm, an image-side radius of curvature of -52.07 mm, a center thickness of 1.8 mm, the material is H-K9L glass, and the diameter is 28.5 mm; the first eyepiece lens has an object-side radius of curvature of -30 mm, an image-side radius of curvature of -56.83 mm, and a center thickness of 1 mm. The first eyepiece is 0.5mm thick, made of H-ZK7 glass, and has a diameter of 26mm; the second eyepiece has an object-side radius of curvature of -135.8mm, an image-side radius of curvature of +18.73mm, a center thickness of 6mm, and is also made of H-ZK7 glass, with a diameter of 26mm; the third eyepiece has an object-side radius of curvature of +48.16mm, an image-side radius of curvature of +18.73mm, a center thickness of 8.9mm, and is also made of H-ZK7 glass, with a diameter of 27mm. The fourth eyepiece lens has an object-side radius of curvature of -18.73 mm, an image-side radius of curvature of +56.83 mm, a center thickness of 1.7 mm, is made of H-ZK71 glass, and has a diameter of 27 mm. The fifth eyepiece lens has an object-side radius of curvature of +26.76 mm, an image-side radius of curvature of +105 mm, a center thickness of 5.9 mm, is made of H-ZK9A glass, and has a diameter of 27 mm. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

[0005] Furthermore, the first objective lens has an object-side radius of curvature of +100.4 mm, an image-side radius of curvature of +384.2 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm; the second objective lens has an object-side radius of curvature of +83.1 mm, an image-side radius of curvature of +134.35 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm; the third objective lens has an object-side radius of curvature of -134.35 mm. The first lens has an object-side radius of curvature of -134.35 mm, a center thickness of 2.5 mm, is made of H-BAF6 glass, and has a diameter of 40.5 mm. The focusing lens has an object-side radius of curvature of +113.59 mm, an image-side radius of curvature of -52.07 mm, a center thickness of 1.8 mm, is made of H-K9L glass, and has a diameter of 28.5 mm. The first eyepiece lens has an object-side radius of curvature of -24.87 mm, an image-side radius of curvature of -47.1 mm, and a center thickness of 2.5 mm. The first eyepiece has a thickness of 1.2mm, is made of H-ZK9A glass, and has a diameter of 23mm. The second eyepiece has an object-side radius of curvature of -111.7mm, an image-side radius of curvature of +15.76mm, a center thickness of 6.5mm, is also made of H-ZK9A glass, and has a diameter of 23mm. The third eyepiece has an object-side radius of curvature of +39.9mm, an image-side radius of curvature of +15.76mm, a center thickness of 9.3mm, and is made of H-ZK7 glass. The diameter is 25mm; the fourth eyepiece lens has an object-side radius of curvature of -15.76mm, an image-side radius of curvature of +47.1mm, a center thickness of 1.4mm, and is made of H-ZK71 glass; the fifth eyepiece lens has an object-side radius of curvature of +22.2mm, an image-side radius of curvature of +87.07mm, a center thickness of 6mm, and is made of H-ZK9A glass. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

[0006] Furthermore, along the optical axis, the distance between the first and second objective lenses is 0.5 mm, the distance between the third objective lens and the focusing lens is 41 mm, the distance between the focusing lens and the half-pentagonal prism is 33 mm, the distance between the roof prism and the rhomboid prism is 10 mm, the distance between the rhomboid prism and the first eyepiece lens is 8.83 mm, the distance between the first and second eyepiece lenses is 2.03 mm, the distance between the second and third eyepiece lenses is 0.2 mm, and the distance between the fourth and fifth eyepiece lenses is 0.3 mm.

[0007] Furthermore, along the optical axis, the distance between the first and second objective lenses is 0.5 mm, the distance between the third objective lens and the focusing lens is 42.5 mm, the distance between the focusing lens and the semi-pentagonal prism is 31.7 mm, the distance between the roof prism and the rhomboid prism is 10 mm, the distance between the rhomboid prism and the first eyepiece lens is 12.17 mm, the distance between the first and second eyepiece lenses is 1.87 mm, the distance between the second and third eyepiece lenses is 0.2 mm, and the distance between the fourth and fifth eyepiece lenses is 0.2 mm.

[0008] Compared with the prior art, the beneficial effects achieved by the present invention are: The telescope optical system of this application has a magnification of 12x. The objective lens group consists of a first objective lens, a second objective lens, and a third objective lens, with a focal length of 218.9mm. The eyepiece group consists of a first eyepiece, a second eyepiece, a third eyepiece, a fourth eyepiece, and a fifth eyepiece, with a focal length of 18.5mm. The overall field of view is 5.4°, the exit pupil diameter is 3.4mm, the exit pupil distance is 18.6mm, the minimum focusing distance is 4m, and the twilight index is 22.45.

[0009] The telescope optical system of this application has a magnification of 16x. The objective lens group consists of a first objective lens, a second objective lens, and a third objective lens, with a focal length of 230.2mm. The eyepiece group consists of a first eyepiece, a second eyepiece, a third eyepiece, a fourth eyepiece, and a fifth eyepiece, with a focal length of 14.8mm. The overall field of view is 4.2°, the exit pupil diameter is 2.46mm, the exit pupil distance is 14.1mm, the minimum focusing distance is 4m, and the twilight index is 25.92. Attached Figure Description

[0010] 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: Figure 1 This is a schematic diagram of the optical system of the present invention; Figure 2 This is a field distortion diagram of Embodiment 1 of the present invention; Figure 3 This is a mesh distortion diagram of Embodiment 1 of the present invention; Figure 4 This is a field distortion diagram of Embodiment 2 of the present invention; Figure 5 This is a mesh distortion diagram of Embodiment 2 of the present invention. Detailed Implementation

[0011] 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. Example 1

[0012] As attached Figure 1-3 As shown, the present invention provides the following technical solution: An optical system for binoculars with a long exit pupil distance is characterized by the following components arranged sequentially along the optical axis from the object side to the image side: a first objective lens 1, a second objective lens 2, a third objective lens 3, a focusing lens 4, a semi-pentaprism 5, a roof prism 6, an oblique prism 7, a first eyepiece lens 8, a second eyepiece lens 9, a third eyepiece lens 10, a fourth eyepiece lens 11, and a fifth eyepiece lens 12. The first objective lens 1 is a biconvex lens; the second objective lens 2 and the third objective lens 3 are cemented lenses; the second objective lens 2 is a biconvex lens; 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 8 and the second eyepiece lens 9 are close together at their edges; the first eyepiece lens 8 is a biconcave lens; the second eyepiece lens 9 is a concave-convex lens with its concave surface facing the object side; the third eyepiece lens 10 and the fourth eyepiece lens 11 form a cemented lens; the third eyepiece lens 10 is a biconvex lens; the fourth eyepiece lens 11 is a concave-convex lens with its concave surface facing the object side; and the fifth eyepiece lens 12 is a biconvex lens. Only these nine lenses in the optical system possess optical power. Objective lens 1 has an object-side radius of curvature of +139.9 mm, an image-side radius of curvature of +263.6 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm. Objective lens 2 has an object-side radius of curvature of +77.6 mm, an image-side radius of curvature of +155.1 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm. Objective lens 3 has an object-side radius of curvature of -155.1 mm, an image-side radius of curvature of +139.9 mm, an image-side radius of curvature of +263.6 mm, a center thickness of 5 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm. The object-side radius of curvature of the focusing lens 4 is -155.1 mm, the center thickness is 2.5 mm, the material is H-BAF5 glass, and the diameter is 40.5 mm; the object-side radius of curvature of the focusing lens 4 is +113.59 mm, the image-side radius of curvature is -52.07 mm, the center thickness is 1.8 mm, the material is H-K9L glass, and the diameter is 28.5 mm; the object-side radius of curvature of the first eyepiece lens 8 is -30 mm, the image-side radius of curvature is -56.83 mm, and the center thickness is 1. The first eyepiece is 5mm thick, made of H-ZK7 glass, and has a diameter of 26mm; the second eyepiece lens 9 has an object-side radius of curvature of -135.8mm, an image-side radius of curvature of +18.73mm, a center thickness of 6mm, and is made of H-ZK7 glass, with a diameter of 26mm; the third eyepiece lens 10 has an object-side radius of curvature of +48.16mm, an image-side radius of curvature of +18.73mm, a center thickness of 8.9mm, and is made of H-ZK7 glass, with a diameter of 27mm. The fourth eyepiece lens 11 has an object-side radius of curvature of -18.73 mm, an image-side radius of curvature of +56.83 mm, a center thickness of 1.7 mm, is made of H-ZK71 glass, and has a diameter of 27 mm. The fifth eyepiece lens 12 has an object-side radius of curvature of +26.76 mm, an image-side radius of curvature of +105 mm, a center thickness of 5.9 mm, is made of H-ZK9A glass, and has a diameter of 27 mm. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

[0013] Along the optical axis, the distance between objective lens 1 and objective lens 2 is 0.5 mm, the distance between objective lens 3 and focusing lens 4 is 41 mm, the distance between focusing lens 4 and half pentaprism 5 is 33 mm, the distance between roof prism 6 and rhomboid prism 7 is 10 mm, the distance between rhomboid prism 7 and eyepiece lens 8 is 8.83 mm, the distance between eyepiece lens 8 and eyepiece lens 9 is 2.03 mm, the distance between eyepiece lens 9 and eyepiece lens 10 is 0.2 mm, and the distance between eyepiece lens 11 and eyepiece lens 12 is 0.3 mm.

[0014] The telescope optical system in this embodiment has a magnification of 12x. The objective lens group consists of a first objective lens, a second objective lens, and a third objective lens, with a focal length of 218.9mm. The eyepiece group consists of a first eyepiece, a second eyepiece, a third eyepiece, a fourth eyepiece, and a fifth eyepiece, with a focal length of 18.5mm. The overall field of view is 5.4°, the exit pupil diameter is 3.4mm, the exit pupil distance is 18.6mm, the minimum focusing distance is 4m, and the twilight index is 22.45.

[0015] Appendix Figure 2 This is the field curvature distortion diagram of this embodiment. Field curvature distortion diagram analysis is an important tool for evaluating the imaging quality of optical systems. It reveals the impact of field curvature and distortion on imaging effects. Also known as image field curvature, it describes how, after a planar object passes through a lens system, the sharp image point formed 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. We will illustrate this through the attached diagram. Figure 2 It can be seen that the field curvature of this application is very small, and the edges and center are relatively clear, resulting in good image quality.

[0016] Appendix Figure 3 The grid distortion in this embodiment is small with no distortion in the image plane, and a small amount of distortion at the edge of the image plane. The overall image quality of the optical system is high, with a maximum distortion of 3.9953%. Example 2

[0017] An optical system for binoculars with a long exit pupil distance is characterized by the following components arranged sequentially along the optical axis from the object side to the image side: a first objective lens 1, a second objective lens 2, a third objective lens 3, a focusing lens 4, a semi-pentaprism 5, a roof prism 6, an oblique prism 7, a first eyepiece lens 8, a second eyepiece lens 9, a third eyepiece lens 10, a fourth eyepiece lens 11, and a fifth eyepiece lens 12. The first objective lens 1 is a biconvex lens; the second objective lens 2 and the third objective lens 3 are cemented lenses; the second objective lens 2 is a biconvex lens; 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 8 and the second eyepiece lens 9 are close together at their edges; the first eyepiece lens 8 is a biconcave lens; the second eyepiece lens 9 is a concave-convex lens with its concave surface facing the object side; the third eyepiece lens 10 and the fourth eyepiece lens 11 form a cemented lens; the third eyepiece lens 10 is a biconvex lens; the fourth eyepiece lens 11 is a concave-convex lens with its concave surface facing the object side; and the fifth eyepiece lens 12 is a biconvex lens. Only these nine lenses in the optical system possess optical power. Furthermore, objective lens 1 has an object-side radius of curvature of +100.4 mm, an image-side radius of curvature of +384.2 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm; objective lens 2 has an object-side radius of curvature of +83.1 mm, an image-side radius of curvature of +134.35 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm; objective lens 3 has an object-side radius of curvature of -134.35 mm. The first lens has an object-side radius of curvature of -134.35 mm, a center thickness of 2.5 mm, is made of H-BAF6 glass, and has a diameter of 40.5 mm. The focusing lens 4 has an object-side radius of curvature of +113.59 mm, an image-side radius of curvature of -52.07 mm, a center thickness of 1.8 mm, is made of H-K9L glass, and has a diameter of 28.5 mm. The first eyepiece lens 8 has an object-side radius of curvature of -24.87 mm, an image-side radius of curvature of -47.1 mm, and a center thickness of 2.5 mm. The first eyepiece has a thickness of 1.2mm, is made of H-ZK9A glass, and has a diameter of 23mm; the second eyepiece lens 9 has an object-side radius of curvature of -111.7mm, an image-side radius of curvature of +15.76mm, a center thickness of 6.5mm, is made of H-ZK9A glass, and has a diameter of 23mm; the third eyepiece lens 10 has an object-side radius of curvature of +39.9mm, an image-side radius of curvature of +15.76mm, a center thickness of 9.3mm, is made of H-ZK7 glass, and has a diameter of... 25mm; the fourth eyepiece lens 11 has an object-side radius of curvature of -15.76mm, an image-side radius of curvature of +47.1mm, a center thickness of 1.4mm, is made of H-ZK71 glass, and has a diameter of 25mm; the fifth eyepiece lens 12 has an object-side radius of curvature of +22.2mm, an image-side radius of curvature of +87.07mm, a center thickness of 6mm, is made of H-ZK9A glass, and has a diameter of 25mm. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

[0018] Along the optical axis, the distance between objective lens 1 and objective lens 2 is 0.5 mm, the distance between objective lens 3 and focusing lens 4 is 42.5 mm, the distance between focusing lens 4 and semi-pentagonal prism 5 is 31.7 mm, the distance between roof prism 6 and rhombic prism 7 is 10 mm, the distance between rhombic prism 7 and eyepiece lens 8 is 12.17 mm, the distance between eyepiece lens 8 and eyepiece lens 9 is 1.87 mm, the distance between eyepiece lens 9 and eyepiece lens 10 is 0.2 mm, and the distance between eyepiece lens 11 and eyepiece lens 12 is 0.2 mm.

[0019] The telescope optical system in this embodiment has a magnification of 16x. The objective lens group consists of a first objective lens, a second objective lens, and a third objective lens, with a focal length of 230.2mm. The eyepiece group consists of a first eyepiece, a second eyepiece, a third eyepiece, a fourth eyepiece, and a fifth eyepiece, with a focal length of 14.8mm. The overall field of view is 4.2°, the exit pupil diameter is 2.46mm, the exit pupil distance is 14.1mm, the minimum focusing distance is 4m, and the twilight index is 25.92.

[0020] Appendix Figure 4 This is the field distortion diagram of this embodiment, compared with the attached diagram. Figure 2 It was found that the field of view was reduced, with a half field of view of only 2.1°, and the distortion was significantly increased.

[0021] Appendix Figure 4 The mesh distortion in this embodiment is 5.2730%, with noticeable edge distortion.

[0022] 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 present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. An optical system for binoculars with a long exit pupil distance, characterized in that: Along the optical axis from the object side to the image side are arranged the following lenses in sequence: first objective lens (1), second objective lens (2), third objective lens (3), focusing lens (4), half pentaprism (5), roof prism (6), rhomboid prism (7), first eyepiece lens (8), second eyepiece lens (9), third eyepiece lens (10), fourth eyepiece lens (11), and fifth eyepiece lens (12). The first objective lens (1) is a biconvex lens, the second objective lens (2) and the third objective lens (3) are cemented lenses, the second objective lens (2) is a biconvex lens, the third objective lens (3) is a biconcave lens, the focusing lens (4) is a concave-convex lens with the convex surface facing the object side, the first eyepiece lens (8) and the second eyepiece lens (9) are close together at the edges, the first eyepiece lens (8) is a biconcave lens, the second eyepiece lens (9) is a concave-convex lens with the concave surface facing the object side, the third eyepiece lens (10) and the fourth eyepiece lens (11) form a cemented lens, the third eyepiece lens (10) is a biconvex lens, the fourth eyepiece lens (11) is a concave-convex lens with the concave surface facing the object side, the fifth eyepiece lens (12) is a biconvex lens, and only the above 9 lenses have optical power in the optical system; The first objective lens (1) has an object-side radius of curvature of +139.9 mm, an image-side radius of curvature of +263.6 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm; the second objective lens (2) has an object-side radius of curvature of +77.6 mm, an image-side radius of curvature of +155.1 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm; the third objective lens (3) has an object-side radius of curvature of -155.1 mm. The image-side radius of curvature is -155.1 mm, the center thickness is 2.5 mm, the material is H-BAF5 glass, and the diameter is 40.5 mm; the focusing lens (4) has an object-side radius of curvature of +113.59 mm, an image-side radius of curvature of -52.07 mm, a center thickness of 1.8 mm, the material is H-K9L glass, and the diameter is 28.5 mm; the first eyepiece lens (8) has an object-side radius of curvature of -30 mm, an image-side radius of curvature of -56.83 mm, and a center thickness of 1. The first eyepiece is 0.5mm thick, made of H-ZK7 glass, and has a diameter of 26mm; the second eyepiece lens (9) has an object-side radius of curvature of -135.8mm, an image-side radius of curvature of +18.73mm, a center thickness of 6mm, made of H-ZK7 glass, and has a diameter of 26mm; the third eyepiece lens (10) has an object-side radius of curvature of +48.16mm, an image-side radius of curvature of +18.73mm, a center thickness of 8.9mm, made of H-ZK7 glass, and has a diameter of 27mm. The fourth eyepiece lens (11) has an object-side radius of curvature of -18.73 mm, an image-side radius of curvature of +56.83 mm, a center thickness of 1.7 mm, is made of glass H-ZK71, and has a diameter of 27 mm. The fifth eyepiece lens (12) has an object-side radius of curvature of +26.76 mm, an image-side radius of curvature of +105 mm, a center thickness of 5.9 mm, is made of glass H-ZK9A, and has a diameter of 27 mm. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

2. The optical system for a binoculars with a long exit pupil distance according to claim 1, characterized in that: The first objective lens (1) has an object-side radius of curvature of +100.4 mm, an image-side radius of curvature of +384.2 mm, a center thickness of 5 mm, is made of H-K9L glass, and has a diameter of 44 mm; the second objective lens (2) has an object-side radius of curvature of +83.1 mm, an image-side radius of curvature of +134.35 mm, a center thickness of 6 mm, is made of H-FK61 glass, and has a diameter of 40.5 mm; the third objective lens (3) has an object-side radius of curvature of -134.35 mm. The image-side radius of curvature is -134.35mm, the center thickness is 2.5mm, the material is H-BAF6 glass, and the diameter is 40.5mm; the focusing lens (4) has an object-side radius of curvature of +113.59mm, an image-side radius of curvature of -52.07mm, a center thickness of 1.8mm, the material is H-K9L glass, and the diameter is 28.5mm; the first eyepiece lens (8) has an object-side radius of curvature of -24.87mm, an image-side radius of curvature of -47.1mm, and a center thickness of 1.8mm. The first eyepiece has a thickness of 1.2mm, is made of glass H-ZK9A, and has a diameter of 23mm; the second eyepiece (9) has an object-side radius of curvature of -111.7mm, an image-side radius of curvature of +15.76mm, a center thickness of 6.5mm, is made of glass H-ZK9A, and has a diameter of 23mm; the third eyepiece (10) has an object-side radius of curvature of +39.9mm, an image-side radius of curvature of +15.76mm, a center thickness of 9.3mm, is made of glass H-ZK7, and has a diameter of 2. 5mm; the fourth eyepiece lens (11) has an object-side radius of curvature of -15.76mm, an image-side radius of curvature of +47.1mm, a center thickness of 1.4mm, is made of glass H-ZK71, and has a diameter of 25mm; the fifth eyepiece lens (12) has an object-side radius of curvature of +22.2mm, an image-side radius of curvature of +87.07mm, a center thickness of 6mm, is made of glass H-ZK9A, and has a diameter of 25mm. In the radius of curvature, "+" indicates a convex surface and "-" indicates a concave surface.

3. The optical system for a binoculars with a long exit pupil distance 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 0.5 mm, the distance between the third objective lens (3) and the focusing lens (4) is 41 mm, the distance between the focusing lens (4) and the half pentaprism (5) is 33 mm, the distance between the roof prism (6) and the rhomboid prism (7) is 10 mm, the distance between the rhomboid prism (7) and the first eyepiece lens (8) is 8.83 mm, the distance between the first eyepiece lens (8) and the second eyepiece lens (9) is 2.03 mm, the distance between the second eyepiece lens (9) and the third eyepiece lens (10) is 0.2 mm, and the distance between the fourth eyepiece lens (11) and the fifth eyepiece lens (12) is 0.3 mm.

4. The optical system for a binoculars with a long exit pupil distance according to claim 2, characterized in that: Along the optical axis, the distance between the first objective lens (1) and the second objective lens (2) is 0.5 mm, the distance between the third objective lens (3) and the focusing lens (4) is 42.5 mm, the distance between the focusing lens (4) and the half pentaprism (5) is 31.7 mm, the distance between the roof prism (6) and the rhomboid prism (7) is 10 mm, the distance between the rhomboid prism (7) and the first eyepiece lens (8) is 12.17 mm, the distance between the first eyepiece lens (8) and the second eyepiece lens (9) is 1.87 mm, the distance between the second eyepiece lens (9) and the third eyepiece lens (10) is 0.2 mm, and the distance between the fourth eyepiece lens (11) and the fifth eyepiece lens (12) is 0.2 mm.

Images