A continuously variable magnification prism telescope optical system

Abstract

The present invention discloses a continuously variable magnification prism telescope optical system, belonging to the technical field of optical telescope systems. The system comprises a first objective lens doublet, a third objective lens, a second objective lens doublet, a third objective lens doublet, a fourth objective lens doublet, a tenth objective lens, a first prism, a graticule, an eyepiece doublet, a fourth eyepiece lens, and a fifth eyepiece lens, arranged in sequence along a first optical path. Most of the objective lenses and eyepieces in the continuously variable magnification prism telescope optical system are doublets, which can effectively shorten the overall length of the optical system and reduce the number of lenses in the optical system, resulting in a smaller volume and weight of the entire optical system after assembly, while also achieving good image quality. The system achieves continuous changes in focal length and / or imaging magnification by moving the second objective lens doublet and / or the third objective lens doublet along the optical axis. The use of a variable magnification objective lens structure makes the eyepiece structure simple and highly reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of optical telescope systems, and in particular relates to a continuously variable magnification prism telescope optical system. Background Art

[0002] Observation scopes are optical instruments used for remote observation and are widely used in environmental and military fields. Conventional observation scopes mostly use fixed-focal-length optical systems with low magnification. Most are monocular, which has certain limitations in practical use and cannot achieve variable observation magnification. Furthermore, the eyepiece magnification used in existing variable-magnification telescopes not only complicates the eyepiece structure but also suffers from a series of problems such as a small magnification ratio, a small field of view, suboptimal clarity, and poor versatility. Therefore, it is necessary to design an optical system with a variable objective lens. Summary of the Invention

[0003] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a continuously variable magnification prism telescope optical system, which can effectively improve the imaging quality of the optical system while reducing the number of lenses in the optical system.

[0004] To achieve the above-mentioned object, the present invention provides a continuously variable magnification prism telescope optical system, which comprises a first objective lens doublet, a third objective lens, a second objective lens doublet, a third objective lens doublet, a fourth objective lens doublet, a tenth objective lens, a first prism, a graticule, an eyepiece doublet, a fourth eyepiece lens, and a fifth eyepiece lens, which are sequentially arranged along a first optical path, wherein:

[0005] The first cemented lens of the objective lens is formed by cementing a first biconvex lens and a first meniscus lens; the third lens of the objective lens is a meniscus lens; the second cemented lens of the objective lens is formed by cementing a second meniscus lens and a second biconcave lens; the third cemented lens of the objective lens is formed by cementing a third biconcave lens and a third meniscus lens; the fourth cemented lens of the objective lens is formed by cementing a fourth meniscus lens and a fourth biconvex lens; the tenth lens of the objective lens is a biconvex lens; the cemented lens of the eyepiece is formed by cementing a fifth meniscus lens, a fifth biconcave lens and a fifth biconvex lens in sequence; the fourth lens of the eyepiece is a meniscus lens, and the fifth lens of the eyepiece is a meniscus lens;

[0006] By moving the second cemented lens of the objective lens and / or the third cemented lens of the objective lens along the optical axis, one or more of the distance between the third lens of the objective lens and the second cemented lens of the objective lens, the distance between the second cemented lens of the objective lens and the third cemented lens, and the distance between the third cemented lens of the objective lens and the fourth cemented lens of the objective lens are adjusted individually or simultaneously to achieve changes in focal length and / or imaging height and magnification.

[0007] As a further improvement of the present invention, the graticule is a glued graticule, and the scale is engraved on the glued surface to improve the smoothness of the graticule, thereby improving the imaging quality.

[0008] As a further improvement of the present invention, the distance from the first cemented lens of the objective lens to the fourth lens of the eyepiece does not exceed 315 mm.

[0009] As a further improvement of the present invention, a first aperture is provided between the third lens of the objective lens and the second cemented lens of the objective lens, and / or a second aperture is provided between the third cemented lens of the objective lens and the fourth cemented lens of the objective lens, so as to improve the image quality throughout the entire zoom range.

[0010] As a further improvement of the present invention, the distance between the third lens of the objective lens and the second cemented lens of the objective lens is adjusted within the range of 7.5 to 9.5 mm;

[0011] The distance between the second cemented lens of the objective lens and the third cemented lens of the objective lens is adjusted within the range of 3.5 to 40.5 mm;

[0012] The distance between the third cemented lens of the objective lens and the fourth cemented lens of the objective lens is adjusted within the range of 2.5 to 37.5 mm.

[0013] As a further improvement of the present invention, the first cemented lens of the objective lens is formed by cementing two lenses made of different materials to correct the chromatic aberration of the objective lens.

[0014] As a further improvement of the present invention, the concave surface and / or the convex surface are both spherical surfaces.

[0015] As a further improvement of the present invention, the continuously variable magnification prism telescope optical system further includes a second optical path symmetrically arranged with respect to the first optical path, and the first optical path and the second optical path form a binocular optical system.

[0016] As a further improvement of the present invention, the first prism is formed by gluing two right-angle prisms together, and the distance between the eyepieces in the telescope binocular optical system is adjusted by rotating the two first prisms.

[0017] As a further improvement of the present invention, the distance between the eyepieces in the first optical path and the second optical path is adjusted within the range of 50 mm to 80 mm.

[0018] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0019] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0020] (1) The continuously variable magnification prism telescope optical system of the present invention, wherein the objective lens and the eyepiece are mainly cemented lenses, can effectively shorten the total length of the optical system, reduce the number of lenses in the optical system, and make the entire optical system smaller in size and weight after assembly. The system objective lens can correct chromatic aberration using only the first cemented lens of the objective lens to achieve good image quality; and can also make less light be absorbed and have better light transmittance.

[0021] (2) The continuously variable magnification prism telescope optical system of the present invention can achieve continuous change of focal length and / or imaging high and low magnification by adjusting one or more of the distance between the third lens of the objective lens and the second cemented lens of the objective lens, the distance between the second cemented lens of the objective lens and the third cemented lens, and the distance between the third cemented lens of the objective lens and the fourth cemented lens, individually or simultaneously. The use of the structure of the objective lens with variable magnification makes the eyepiece structure simple and highly reliable.

[0022] (3) The continuously variable magnification prism telescope optical system of the present invention improves the image quality by setting the graticule plate as a glued graticule plate and engraving the graticule on the glued surface; and by setting a first aperture between the third lens of the objective lens and the second glued lens of the objective lens, and setting a second aperture between the third glued lens of the objective lens and the fourth glued lens of the objective lens, so as to improve the image quality throughout the entire zoom range.

[0023] (4) The continuously variable magnification prism telescope optical system of the present invention forms a binocular optical system by setting a second optical path symmetrically arranged with the first optical path, and glues two right-angle prisms into a first prism. By rotating the first prism in the two optical paths to adjust the distance between the eyepieces in the first optical path and the second optical path, the binocular distance of the continuously variable magnification prism telescope optical system can be adjusted within a range of 50 mm to 80 mm, thereby improving the application range of the continuously variable magnification prism telescope optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 1 is an overall schematic diagram of the optical system of a continuously variable magnification prism telescope according to an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the overall structure of the optical system of the continuously variable magnification prism telescope in an embodiment of the present invention;

[0027] Figure 3This is a short-focus ray diagram of the continuously variable magnification prism telescope optical system in an embodiment of the present invention (the first prism is unfolded into a flat plate);

[0028] Figure 4 This is a long-focus ray diagram of the continuously variable magnification prism telescope optical system in an embodiment of the present invention (the first prism is unfolded into a flat plate);

[0029] Figure 5 1 is a diagram of short-focus field curvature and distortion of the continuously variable magnification prism telescope optical system in an embodiment of the present invention;

[0030] Figure 6 1 is a diagram of the long-focus field curvature and distortion of the continuously variable magnification prism telescope optical system in an embodiment of the present invention;

[0031] Figure 7 1 is a short-focus axial aberration curve diagram of the continuously variable magnification prism telescope optical system in an embodiment of the present invention;

[0032] Figure 8 is a graph showing a long-focus axial aberration of the continuously variable magnification prism telescope optical system according to an embodiment of the present invention;

[0033] Figure 9 1 is a short-focus vertical axis aberration curve diagram of the continuously variable magnification prism telescope optical system in an embodiment of the present invention;

[0034] Figure 10 This is a long-focus vertical axis aberration curve diagram of the continuously variable magnification prism telescope optical system in an embodiment of the present invention.

[0035] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0036] 10. First cemented lens of objective lens; 11. First biconvex lens; 12. First meniscus lens; 20. Third lens of objective lens; 30. Second cemented lens of objective lens; 31. Second meniscus lens; 32. Second biconcave lens; 40. Third cemented lens of objective lens; 41. Third biconcave lens; 42. Third meniscus lens; 50. Fourth cemented lens of objective lens; 51. Fourth meniscus lens; 52. Fourth biconvex lens; 60. Tenth lens of objective lens; 70. First prism; 80. Graticule; 90. Eyepiece cemented lens; 91. Fifth meniscus lens; 92. Fifth biconcave lens; 93. Fifth biconvex lens; 100. Fourth lens of eyepiece; 110. Fifth lens of eyepiece; 120. First aperture; 130. Second aperture. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0040] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] Example:

[0043] See also Figure 1 The continuously variable magnification prism telescope optical system in the preferred embodiment of the present invention includes an objective first cemented lens 10, an objective third lens 20, an objective second cemented lens 30, an objective third cemented lens 40, an objective fourth cemented lens 50, an objective tenth lens 60, a first prism 70, a graticule 80, an eyepiece cemented lens 90, an eyepiece fourth lens 100 and an eyepiece fifth lens 110, which are arranged in sequence along a first optical path, thereby constituting the optical device structure of the entire optical system.

[0044] Among them, the first objective lens 10 is a first double convex lens 11 and a first meniscus lens 12 glued together; the third objective lens 20 is a meniscus lens; the second objective lens 30 is a second meniscus lens 31 and a second double concave lens 32 glued together; the third objective lens 40 is a third double concave lens 41 and a third meniscus lens 42 glued together; the fourth objective lens 50 is a fourth meniscus lens 51 and a fourth double convex lens 52 glued together; the tenth objective lens 60 is a double convex lens; the eyepiece glued lens (90) is a fifth meniscus lens 91, a fifth double concave lens 92 and a fifth double convex lens 93 glued together in sequence; the fourth eyepiece lens 100 is a meniscus lens, and the fifth eyepiece lens 110 is a meniscus lens. The objective lens and the eyepiece in this optical system mainly adopt glued lenses, which can effectively shorten the total length of the optical system, reduce the number of lenses in the optical system, and make the entire optical system smaller in size and weight after assembly.

[0045] Preferably, the first meniscus lens 12 and the fourth meniscus lens 51 are negative meniscus lenses, and the objective lens third lens 20, the second meniscus lens 31, the third meniscus lens 42, the fifth meniscus lens 91, the eyepiece fourth lens 100, and the eyepiece fifth lens 110 are positive meniscus lenses.

[0046] Specifically, along the direction of incidence of light, the front surface of the first cemented lens 10 of the objective lens is convex, and the rear surface is convex; the front surface of the third lens 20 of the objective lens is convex, and the rear surface is concave; the front surface of the second cemented lens 30 of the objective lens is concave, and the rear surface is concave; the front surface of the third cemented lens 40 of the objective lens is concave, and the rear surface is concave; the front surface of the fourth cemented lens 50 of the objective lens is convex, and the rear surface is convex; the front surface of the tenth lens 60 of the objective lens is convex, and the rear surface is convex; the front surface of the eyepiece cemented lens 90 is concave, and the rear surface is convex; the front surface of the fourth lens 100 of the eyepiece is concave, and the rear surface is convex; the front surface of the fifth lens 110 of the eyepiece is convex, and the rear surface is concave.

[0047] Preferably, the concave surface and / or convex surface of each lens is a spherical surface, so that the production cost of each lens is low and it is easy to process, test and assemble.

[0048] Preferably, the first cemented lens 10 of the objective lens is formed by cementing two lenses made of different materials to correct the chromatic aberration of the objective lens.

[0049] In an optional embodiment, the left end curvature radius of the first biconvex lens 11 of the first cemented lens 10 of the objective lens is selected to be 190 mm ~ 200 mm, the right end curvature radius is -220 mm ~ -210 mm, and the center thickness is 13 mm ~ 13.5 mm; the left end curvature radius of the first meniscus lens 12 is -220 mm ~ -210 mm, the right end curvature radius is -1040 mm ~ -1030 mm, and the center thickness is 4 mm ~ 4.5 mm.

[0050] like Figure 1 As shown, light enters the optical system and passes through the two lenses of the first objective lens 10 to eliminate chromatic aberration, and then passes through the third objective lens 20, the second objective lens 30, the third objective lens 40, the fourth objective lens 50, and the tenth objective lens 60. Preferably, the left end curvature radius of the third objective lens 20 is 135mm-140mm, and the right end curvature radius is 700mm ~750mm, with a center thickness of 9mm~9.5mm; the left end radius of curvature of the second meniscus lens 31 of the second cemented lens 30 of the objective lens is -170mm~-160mm, the right end radius of curvature is -40mm~-30mm, and the center thickness is 3mm~3.5mm; the left end radius of curvature of the second biconcave lens 32 is -40mm~-30mm, the right end radius of curvature is 50mm~60mm, and the center thickness is 1.5mm~2mm; the left end radius of curvature of the third biconcave lens 41 of the third cemented lens 40 of the objective lens is -65mm~-60mm, the right end radius of curvature is 13mm~14mm, and the center thickness is 1.5mm~2mm; the left end radius of curvature of the third meniscus lens 42 is 13mm~14mm, and the right end radius of curvature is 35 mm ~40mm, and the center thickness is 4mm~4.5mm; the left end radius of curvature of the fourth meniscus lens 51 of the fourth cemented lens 50 of the objective lens is 50mm~55mm, the right end radius of curvature is 25mm~30mm, and the center thickness is 2mm~2.5mm; the left end radius of curvature of the fourth biconvex lens 52 is 25mm~30mm, the right end radius of curvature is -150mm~-145mm, and the center thickness is 6mm~6.5mm; the left end radius of curvature of the tenth lens 60 of the objective lens is 130mm~135mm, the right end radius of curvature is -100 mm ~-95mm, and the center thickness is 3.5mm~4mm.

[0051] Preferably, at least one of the second and third objective lens 30, 40 is movable, i.e., can be operated to move unidirectionally or back and forth along the optical path. For example, the second and third objective lens 30, 40 can each be individually movable along the optical path, or both can be simultaneously movable along the optical path, or both can be simultaneously movable along the optical path. Utilizing the above movable manner, the spacing T1 between the third objective lens 20 and the second and third objective lens 30, the spacing T2 between the second and third objective lens 30, 40, and the spacing T3 between the third and fourth objective lens 40, 50 can be adjusted.

[0052] Specifically and preferably, T1 can be adjusted within the range of 7.5mm to 9.5mm, T2 can be adjusted within the range of 3.5mm to 40.5mm, and T3 can be adjusted within the range of 2.5mm to 37.5mm. By adjusting T1, T2 or T3 alone, or one or more of T1, T2 and T3 at the same time, the focal length and / or imaging high and low magnification changes can be achieved. Specifically, in an optional embodiment, a movement curve, such as a nonlinear movement curve, can be set for the second cemented lens 30 of the objective lens and the third cemented lens 40 of the objective lens, and a guide curve groove can be machined in the zoom tube according to the curve to ensure that the zoom hand wheel can rotate smoothly during the continuous zoom process, thereby changing the value of T1, T2 or T3 to achieve the function of changing the focal length and realizing the zoom function.

[0053] Preferably, a first aperture 120 is provided between the third lens 20 of the objective lens and the second cemented lens 30 of the objective lens, and / or a second aperture 130 is provided between the third cemented lens 40 of the objective lens and the fourth cemented lens 50 of the objective lens, so as to improve the image quality throughout the zoom range.

[0054] The light after passing through the tenth lens 60 of the objective lens enters the first prism 70. Preferably, the first prism 70 can be formed by gluing two right-angle prisms. Figure 3 and Figure 4 They are respectively the short-focus ray diagram and the long-focus ray diagram when the first prism 70 is unfolded into a flat plate.

[0055] After passing through first prism 70, light enters eyepiece cemented lens 90, eyepiece fourth lens 100, and eyepiece fifth lens 110 through dividing plate 80. Preferably, dividing plate 80 is a cemented dividing plate, and the divisions are engraved on the cemented surface to improve the smoothness of the dividing plate and thus improve the imaging quality.

[0056] Preferably, the left end radius of curvature of the fifth meniscus lens 91 of the eyepiece cemented lens 90 is -280mm~-290mm, the right end radius of curvature is -20mm~-15mm, and the center thickness is 9mm~9.5mm; the left end radius of curvature of the fifth biconcave lens 92 is -20mm~-15mm, the right end radius of curvature is 35mm~40mm, and the center thickness is 1.5mm~2mm; the left end radius of curvature of the fifth biconvex lens 93 is 35mm~40mm, the right end radius of curvature is -35mm~-30mm, and the center thickness is 8.5mm~9mm; the left end radius of curvature of the fourth lens 100 of the eyepiece is -1300mm~-1280mm, the right end radius of curvature is -70mm~-65mm, and the center thickness is 3.5mm~4mm; the left end radius of curvature of the fifth lens 110 of the eyepiece is 25mm~30mm, and the right end radius of curvature is 165mm ~170mm, center thickness is 6mm~6.5mm.

[0057] In the embodiment of the present application, the zoom optical system designed with the above structure has a magnification range of 15x (short focal length) to 42x (telephoto length); an exit pupil distance greater than 25mm; an exit pupil diameter greater than 6mm at low magnifications, and greater than 2.3mm at high magnifications. In this application, the relative movement of the second objective doublet 30 and the third objective doublet 40 enables the system to achieve a continuous magnification range of 15x to 42x, maintaining good image quality during zooming.

[0058] Figure 5-Figure 8 The following are the field curvature and distortion diagrams and axial aberration curves of the continuously variable magnification prism telescope optical system at short and long focal lengths in the embodiment of the present invention. Figure 5-8 It can be seen that this optical system has good optical performance and achieves the characteristics of large field of view, low distortion and low chromatic aberration.

[0059] Table 1 is the parameter specifications of each optical element lens in the optical system of the embodiment of the present application

[0060]

[0061] More preferably, Figure 2 As shown, the continuously variable magnification prism telescope optical system of the present invention further includes a second optical path symmetrically arranged with the first optical path, and the first optical path and the second optical path form a binocular optical system.

[0062] Preferably, the first prism 70 in the binocular system is formed by gluing two right-angle prisms together, and the distance T4 between the eyepieces in the first light path and the second light path is adjusted by rotating the two first prisms 70. Preferably, the adjustment range of T4 is 50 mm to 80 mm.

[0063] See Figure 9 、 10 They are respectively the short-focus vertical axis aberration curve diagram and the long-focus vertical axis aberration curve diagram of the continuously variable magnification prism telescope optical system in the embodiment of the present invention. It can be seen that the optical axis consistency of the optical system at high and low magnification is good, with horizontal <20" and vertical <20".

[0064] The continuous zoom optical system of the present invention has a large degree of freedom in design and many variables can be selected for the optical system optimization design, so that the optical system aberration design can easily achieve excellent results and obtain excellent image quality.

[0065] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A continuously variable magnification prism telescope optical system, characterized in that: include: The first objective lens (10), the third objective lens (20), the second objective lens (30), the third objective lens (40), the fourth objective lens (50), the tenth objective lens (60), the first prism (70), the graticule (80), the eyepiece lens (90), the fourth eyepiece lens (100) and the fifth eyepiece lens (110) are sequentially arranged along the first optical path, wherein: The first objective lens (10) is formed by gluing a first biconvex lens (11) and a first meniscus lens (12); the third objective lens (20) is a meniscus lens; the second objective lens (30) is formed by gluing a second meniscus lens (31) and a second biconcave lens (32); the third objective lens (40) is formed by gluing a third biconcave lens (41) and a third meniscus lens (42); the fourth objective lens (50) is formed by gluing a fourth meniscus lens (51) and a fourth biconvex lens (52); the tenth objective lens (60) is a biconvex lens; the eyepiece lens (90) is formed by gluing a fifth meniscus lens (91), a fifth biconcave lens (92) and a fifth biconvex lens (93) in sequence; the fourth eyepiece lens (100) is a meniscus lens, and the fifth eyepiece lens (110) is a meniscus lens; By moving the second cemented lens (30) and / or the third cemented lens (40) of the objective lens along the optical axis, one or more of the distance between the third lens (20) of the objective lens and the second cemented lens (30), the distance between the second cemented lens (30) of the objective lens and the third cemented lens (40), and the distance between the third cemented lens (40) of the objective lens and the fourth cemented lens (50) of the objective lens are adjusted individually or simultaneously, so as to achieve a change in focal length and / or imaging height and magnification.

2. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: The graticule (80) is a glued graticule, and the graticule is engraved on the glued surface to improve the smoothness of the graticule, thereby improving the imaging quality.

3. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: The distance between the first cemented lens (10) of the objective lens and the fourth lens (100) of the eyepiece lens does not exceed 315 mm.

4. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: A first diaphragm (120) is provided between the third lens (20) of the objective lens and the second cemented lens (30) of the objective lens, and / or a second diaphragm (130) is provided between the third cemented lens (40) of the objective lens and the fourth cemented lens (50) of the objective lens, so as to improve the image quality throughout the zoom range.

5. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: The distance between the third lens (20) of the objective lens and the second cemented lens (30) of the objective lens is adjusted within the range of 7.5 to 9.5 mm; The distance between the second cemented lens (30) of the objective lens and the third cemented lens (40) of the objective lens is adjusted within the range of 3.5 to 40.5 mm; The distance between the third cemented lens (40) of the objective lens and the fourth cemented lens (50) of the objective lens is adjusted within the range of 2.5 to 37.5 mm.

6. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: The first cemented lens (10) of the objective lens is formed by cementing two lenses made of different materials to correct the chromatic aberration of the objective lens.

7. The continuously variable magnification prism telescope optical system according to claim 1, characterized in that: The concave and / or convex surfaces of each lens are spherical.

8. The continuously variable magnification prism telescope optical system according to any one of claims 1 to 7, characterized in that: It also includes a second optical path symmetrically arranged with the first optical path, and the first optical path and the second optical path form a binocular optical system.

9. The continuously variable magnification prism telescope optical system according to claim 8, characterized in that: The first prism (70) is formed by gluing two right-angle prisms together, and the distance between the eyepieces in the first light path and the second light path can be adjusted by rotating the two first prisms.

10. The continuously variable magnification prism telescope optical system according to claim 9, characterized in that: The distance between the eyepieces in the first optical path and the second optical path is adjusted within the range of 50 mm to 80 mm.

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