Large-view-field telescope optical system

Abstract

The invention belongs to the technical field of telescope manufacturing, and discloses a large-view-field telescope optical system which is characterized in that a first objective lens, a second objective lens, a third objective lens, a focusing lens, a semi-pentaprism, a roof prism, a first eyepiece lens, a second eyepiece lens and a third eyepiece lens are sequentially designed from the object side to the image side in the optical axis direction. According to the optical system, only the ten lenses have diopters, the requirement for the field of view of 6.7 degrees under the 8-fold condition is met, and the exit pupil distance reaches 22.6 mm.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of telescope production technology, and particularly relates to a large field of view telescope optical system. BACKGROUND

[0002] A telescope is an instrument for observing distant objects in the daytime, and many parameters need to be adjusted and balanced in the design process of the telescope, such as magnification, field of view, focal length, exit pupil distance, etc. At present, there are few large field of view telescope optical systems on the market. SUMMARY

[0003] The present application aims to provide a large field of view telescope optical system, which uses the cooperation of multiple objective lenses and eyepieces to achieve a 6.7° field of view at 8 times magnification, and the entire telescope optical system is more reasonable.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is: A large field of view telescope optical system, characterized in that: along the optical axis direction from the object side to the image side, there are in sequence an objective lens first lens, an objective lens second lens, an objective lens third lens, a focusing mirror, a half-pentaprism, a roof 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. The objective lens first lens is a double-convex lens, the objective lens second lens and the objective lens third lens form a cemented lens, the objective lens second lens is a double-convex lens, the objective lens third lens is a double-concave lens, the focusing mirror is a concave-convex lens with the convex surface facing the object side; the eyepiece first lens and the eyepiece second lens form a cemented lens, the eyepiece first lens is a double-concave lens, the eyepiece second lens is a double-convex lens, the eyepiece third lens is a concave-convex lens with the concave surface facing the object side, the eyepiece fourth lens and the eyepiece fifth lens form a cemented lens, the eyepiece fourth lens is a double-convex lens, the eyepiece fifth lens is a concave-convex lens with the concave surface facing the object side, the eyepiece sixth lens is a plano-convex lens with the convex surface facing the object side, and only the above 10 lenses in the optical system have refractive power.

[0005] As a further improvement of the present application, the first lens of the objective lens has a material of glass H-K9L, a curvature radius of 136.14mm on the object side, a curvature radius of -265.5mm on the image side, and a center thickness of 4.7mm; the second lens of the objective lens has a material of glass H-FK61, a curvature radius of 56.75mm on the object side, a curvature radius of -180.3mm on the image side, and a center thickness of 7.6mm; the third lens of the objective lens has a material of glass H-F4, a curvature radius of -180.3mm on the object side, a curvature radius of 180.3mm on the image side, and a center thickness of 3.5mm; the focusing mirror has a material of glass H-K9L, a curvature radius of 124.17mm on the object side, a curvature radius of 47.42mm on the image side, and a center thickness of 2.3mm; the first lens of the ocular lens has a material of glass H-K9L, a curvature radius of -48.64mm on the object side, a curvature radius of 48.64mm on the image side, and a center thickness of 3.8mm; the second lens of the ocular lens has a material of glass H-ZLAF50B, a curvature radius of 48.64mm on the object side, a curvature radius of -61.09mm on the image side, and a center thickness of 4.2mm; the third lens of the ocular lens has a material of glass H-ZK3, a curvature radius of -42.07mm on the object side, a curvature radius of -25.84mm on the image side, and a center thickness of 4mm; the fourth lens of the ocular lens has a material of glass H-ZK3, a curvature radius of 40.331mm on the object side, a curvature radius of -34.106mm on the image side, and a center thickness of 8.6mm; the fifth lens of the ocular lens has a material of glass H-ZF52A, a curvature radius of -34.106mm on the object side, a curvature radius of 170.868mm on the image side, and a center thickness of 1.4mm; and the sixth lens of the ocular lens has a material of glass H-ZK3, a curvature radius of 24.032mm on the object side, and a flat surface on the image side, with a center thickness of 7.5mm.

[0006] As a further improvement of the present application, the profile diameter of the first lens of the objective lens, the second lens of the objective lens, and the third lens of the objective lens is 43mm, the profile diameter of the focusing mirror is 26mm, the profile diameter of the first lens of the ocular lens and the second lens of the ocular lens is 27mm, and the profile diameter of the third lens of the ocular lens, the fourth lens of the ocular lens, the fifth lens of the ocular lens, and the sixth lens of the ocular lens is 31mm.

[0007] As a further improvement of the present application, the distance between the first lens of the objective lens and the second lens of the objective lens along the optical axis is 0.5mm, the distance between the third lens of the objective lens and the focusing mirror is 32.59mm, the distance between the focusing mirror and the half-pentaprism is 20mm, the distance between the roof prism and the first lens of the ocular lens is 22.35mm, the distance between the second lens of the ocular lens and the third lens of the ocular lens is 3.54mm, the distance between the third lens of the ocular lens and the fourth lens of the ocular lens is 0.3mm, and the distance between the fifth lens of the ocular lens and the sixth lens of the ocular lens is 0.3mm.

[0008] The beneficial effects of the present application are as follows: The total length of the whole optical system is 151.39 mm, and the field of view of 6.7° is achieved in the case of 8 times, the exit pupil diameter is 5 mm, the exit pupil distance is 22.6 mm, the first lens of the objective lens, the second lens of the objective lens, the third lens of the objective lens, the objective lens front group, the focal length of the objective lens front group is 93.54 mm, the objective lens front group and the focusing lens form the objective lens group, the focal length of the objective lens group is 147.87 mm, the first lens of the eyepiece, the second lens of the eyepiece, the third lens of the eyepiece, the fourth lens of the eyepiece, the fifth lens of the eyepiece, the sixth lens of the eyepiece form the eyepiece group, and the focal length of the eyepiece group is 18.5 mm. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic diagram of the optical system structure of the present application; Figure 2 is the field curvature distortion chart of the present application; Figure 3 is the aberration chart of the present application. DETAILED DESCRIPTION

[0010] The present application will be further described below in combination with the drawings.

[0011] A large field of view telescope optical system, characterized in that: along the optical axis direction from the object side to the image side, there are in turn an objective lens first lens 1, an objective lens second lens 2, an objective lens third lens 3, a focusing lens 4, a half five prism 5, a ridge prism 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, and an eyepiece sixth lens 12. The objective lens first lens 1 is a double convex lens, the objective lens second lens 2 and the objective lens third lens 3 form a cemented lens, the objective lens second lens 2 is a double convex lens, the objective lens third lens 3 is a double concave lens, the focusing lens 4 is a concave-convex lens with the convex surface facing the object side; the eyepiece first lens 7 and the eyepiece second lens 8 form a cemented lens, the eyepiece first lens 7 is a double concave lens, the eyepiece second lens 8 is a double convex lens, the eyepiece third lens 9 is a concave-convex lens with the concave surface facing the object side, the eyepiece fourth lens 10 and the eyepiece fifth lens 11 form a cemented lens, the eyepiece fourth lens 10 is a double convex lens, the eyepiece fifth lens 11 is a concave-convex lens with the concave surface facing the object side, the eyepiece sixth lens 12 is a plano-convex lens with the convex surface facing the object side, and only the above 10 lenses of the optical system have refractive power.

[0012] As a further improvement of the application, the first lens 1 of the objective has a material of glass H-K9L, an object-side radius of curvature of 136.14 mm, an image-side radius of curvature of -265.5 mm, and a center thickness of 4.7 mm; the second lens 2 of the objective has a material of glass H-FK61, an object-side radius of curvature of 56.75 mm, an image-side radius of curvature of -180.3 mm, and a center thickness of 7.6 mm; the third lens 3 of the objective has a material of glass H-F4, an object-side radius of curvature of -180.3 mm, an image-side radius of curvature of 180.3 mm, and a center thickness of 3.5 mm; the focusing lens 4 has a material of glass H-K9L, an object-side radius of curvature of 124.17 mm, an image-side radius of curvature of 47.42 mm, and a center thickness of 2.3 mm; the first lens 7 of the eyepiece has a material of glass H-K9L, an object-side radius of curvature of -48.64 mm, an image-side radius of curvature of 48.64 mm, and a center thickness of 3.8 mm; the second lens 8 of the eyepiece has a material of glass H-ZLAF50B, an object-side radius of curvature of 48.64 mm, an image-side radius of curvature of -61.09 mm, and a center thickness of 4.2 mm; the third lens 9 of the eyepiece has a material of glass H-ZK3, an object-side radius of curvature of -42.07 mm, an image-side radius of curvature of -25.84 mm, and a center thickness of 4 mm; the fourth lens 10 of the eyepiece has a material of glass H-ZK3, an object-side radius of curvature of 40.331 mm, an image-side radius of curvature of -34.106 mm, and a center thickness of 8.6 mm; the fifth lens 11 of the eyepiece has a material of glass H-ZF52A, an object-side radius of curvature of -34.106 mm, an image-side radius of curvature of 170.868 mm, and a center thickness of 1.4 mm; and the sixth lens 12 of the eyepiece has a material of glass H-ZK3, an object-side radius of curvature of 24.032 mm, and an image-side radius of curvature of 0 mm, with a center thickness of 7.5 mm.

[0013] As a further improvement of the application, the first lens 1 of the objective, the second lens 2 of the objective, and the third lens 3 of the objective have a profile diameter of 43 mm, the focusing lens 4 has a profile diameter of 26 mm, the first lens 7 of the eyepiece and the second lens 8 of the eyepiece have a profile diameter of 27 mm, and the third lens 9 of the eyepiece, the fourth lens 10 of the eyepiece, the fifth lens 11 of the eyepiece, and the sixth lens 12 of the eyepiece have a profile diameter of 31 mm.

[0014] As a further improvement of the present invention, the distance between the first objective lens 1 and the second objective lens 2 along the optical axis is 0.5 mm, the distance between the third objective lens 3 and the focusing lens 4 is 32.59 mm, the distance between the focusing lens 4 and the semi-pentagonal prism 5 is 20 mm, the distance between the roof prism 6 and the first eyepiece lens 7 is 22.35 mm, the distance between the second eyepiece lens 8 and the third eyepiece lens 9 is 3.54 mm, the distance between the third eyepiece lens 9 and the fourth eyepiece lens 10 is 0.3 mm, and the distance between the fifth eyepiece lens 11 and the sixth eyepiece lens 12 is 0.3 mm.

[0015] The total length of the entire optical system is 151.39 mm, achieving a field of view of 6.7° at 8x magnification, with an exit pupil diameter of 5 mm and an exit pupil distance of 22.6 mm. The first, second, and third objective lenses form the front objective group, with a focal length of 93.54 mm. The front objective group and the focusing lens form the objective group, with a focal length of 147.87 mm. The first, second, third, fourth, fifth, and sixth eyepiece lenses form the eyepiece group, with a focal length of 18.5 mm.

[0016] Appendix Figure 2 The field curvature distortion diagram of this invention shows that the meridional field curvature (solid line) and sagittal field curvature (dashed line) curves have similar field curvature values ​​in the paraxial field of view, indicating good on-axis image quality. As the field of view increases, the curves gradually separate, indicating that there is a certain field curvature in the off-axis field of view, but the overall deviation is small, indicating that the system has a good field curvature correction effect. In the distortion diagram, the three curves of different wavelengths basically overlap in the entire field of view, and the distortion value is close to 0 when the field of view is small. As the field of view increases, the distortion value gradually increases, but the overall increase is relatively slow, indicating that the system has small distortion and good consistency of distortion at different wavelengths, and the distortion correction effect is ideal.

[0017] Appendix Figure 3 This is the chromatic aberration curve of the present invention. A chromatic aberration curve is a visualization tool that shows the chromatic aberration phenomenon in the imaging of an optical system. It reveals that because the lens has different refractive indices for different wavelengths of light, multicolored light is separated after passing through the lens and cannot be focused on the same point, thus producing chromatic aberration on the imaging surface. Under visible light conditions, the optical system of this application shows that the three curves have a high degree of overlap under the same field of view at different wavelengths, and the imaging quality is also good.

[0018] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims with respect to the figures of the patent document.

Claims

1. A large field of view telescope optical system characterized by: The first lens (1), the second lens (2), the third lens (3), the focusing lens (4), the half pentagonal prism (5), the roof prism (6), the first eyepiece lens (7), the second eyepiece lens (8), the third eyepiece lens (9), the fourth eyepiece lens (10), the fifth eyepiece lens (11) and the sixth eyepiece lens (12) are sequentially arranged along the optical axis from the object side to the image side. The first lens (1) is a biconvex lens, the second lens (2) and the third lens (3) form a cemented lens, the second lens (2) is a biconvex lens, the third lens (3) is a biconcave lens, the focusing lens (4) is a meniscus lens with the 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, the second eyepiece lens (8) is a biconvex lens, the third eyepiece lens (9) is a meniscus lens with the 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 biconvex lens, the fifth eyepiece lens (11) is a meniscus lens with the concave surface facing the object side, the sixth eyepiece lens (12) is a plano-convex lens with the convex surface facing the object side, and only the above 10 lenses have refractive power.

2. A large field of view telescope optical system according to claim 1, characterized in that: The object side curvature radius of the first lens (1) of the objective lens is 136.14 mm, the image side curvature radius is -265.5 mm, the central thickness is 4.7 mm, and the material is glass H-K9L; the object side curvature radius of the second lens (2) of the objective lens is 56.75 mm, the image side curvature radius is -180.3 mm, the central thickness is 7.6 mm, and the material is glass H-FK61; the object side curvature radius of the third lens (3) of the objective lens is -180.3 mm, the image side curvature radius is 180.3 mm, the central thickness is 3.5 mm, and the material is glass H-F4; the object side curvature radius of the focusing mirror (4) is 124.17 mm, the image side curvature radius is 47.42 mm, the central thickness is 2.3 mm, and the material is glass H-K9L; the object side curvature radius of the first lens (7) of the ocular lens is -48.64 mm, the image side curvature radius is 48.64 mm, the central thickness is 3.8 mm, and the material is glass H-K9L; the object side curvature radius of the second lens (8) of the ocular lens is 48.64 mm, the image side curvature radius is -61.09 mm, the central thickness is 4.2 mm, and the material is glass H-ZLAF50B; the object side curvature radius of the third lens (9) of the ocular lens is -42.07 mm, the image side curvature radius is -25.84 mm, the central thickness is 4 mm, and the material is glass H-ZK3; the object side curvature radius of the fourth lens (10) of the ocular lens is 40.331 mm, the image side curvature radius is -34.106 mm, the central thickness is 8.6 mm, and the material is glass H-ZK3; the object side curvature radius of the fifth lens (11) of the ocular lens is -34.106 mm, the image side curvature radius is 170.868 mm, the central thickness is 1.4 mm, and the material is glass H-ZF52A; the object side curvature radius of the sixth lens (12) of the ocular lens is 24.032 mm, the image side is a plane, the central thickness is 7.5 mm, and the material is glass H-ZK3.

3. A large field of view telescope optical system according to claim 1, characterized in that: The profile diameter of the first lens (1), the second lens (2), and the third lens (3) of the objective lens is 43 mm, the profile diameter of the focusing mirror (4) is 26 mm, the profile diameter of the first lens (7) and the second lens (8) of the ocular lens is 27 mm, and the profile diameter of the third lens (9), the fourth lens (10), the fifth lens (11), and the sixth lens (12) of the ocular lens is 31 mm.

4. The optical system of claim 1, wherein: The distance between the first lens (1) and the second lens (2) of the objective lens along the optical axis direction is 0.5 mm, the distance between the third lens (3) and the focusing mirror (4) is 32.59 mm, the distance between the focusing mirror (4) and the half-pentaprism (5) is 20 mm, the distance between the roof prism (6) and the first lens (7) of the ocular lens is 22.35 mm, the distance between the second lens (8) and the third lens (9) of the ocular lens is 3.54 mm, the distance between the third lens (9) and the fourth lens (10) of the ocular lens is 0.3 mm, and the distance between the fifth lens (11) and the sixth lens (12) of the ocular lens is 0.3 mm.

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