A continuously variable zoom lens relay telescope optical system

Abstract

The application discloses a continuously variable magnification lens relay telescope optical system, which comprises, sequentially arranged along an optical path, an objective lens, an optical path folding assembly, a graticule mirror, a field lens, a relay first lens, a relay second lens, a diaphragm and an ocular lens, wherein the objective lens is a two-piece cemented lens formed by cementing a negative meniscus lens and a double convex lens; the optical path folding assembly comprises oppositely arranged first and second reflectors, and light rays passing through the objective lens cemented lens are folded in optical path after being reflected by the first and second reflectors in sequence; by adjusting one or more of the spacing between the field lens and the relay first lens, the spacing between the relay first lens and the relay second lens and the spacing between the relay second lens and the diaphragm, the focal length and / or the imaging high-low magnification can be changed. The optical system can effectively shorten the total length of the optical system, reduce the number of lenses of the optical system and effectively improve the imaging quality of the optical system.

Description

Technical Field

[0001] This invention belongs to the field of optical telescope system technology, and specifically relates to a continuously zoom telescope optical system. Background Technology

[0002] Observation scopes are optical instruments used for remote observation and are widely used in environmental and military fields. Conventional observation scopes mostly employ optical systems with fixed focal lengths and low magnification, which limits their practical use and prevents the application of varying magnification.

[0003] Chinese patent document CN207586530U discloses a continuous zoom target viewing optical system, such as Figure 1 As shown, the system includes, from left to right along the optical axis, a first objective lens, a second objective lens, a third objective lens, a focusing lens, a roof prism, a first cemented eyepiece lens, a second eyepiece lens, a third cemented eyepiece lens, a fourth eyepiece lens, and a fifth eyepiece lens. The first and second objective lenses are biconvex, the third objective lens is concave, the focusing lens is a cemented meniscus lens with its concave side facing the eyepiece, the first cemented eyepiece lens is biconcave, the second eyepiece lens has a horizontal structure on the left and a convex structure on the right, the third cemented eyepiece lens is biconvex, the fourth eyepiece lens has a horizontal structure on the left and a convex structure on the right, and the fifth eyepiece lens has a convex structure on the left. This optical system, through its rational optical system design, enables a large-aperture observation scope to have continuous magnification capabilities, ranging from 20*60*82, offering strong adaptability and a compact product structure.

[0004] However, to achieve continuous magnification, the objective lens of this type of continuous zoom telescope optical system typically has a long focal length at its telephoto end. Second-order spectral aberrations are the primary aberrations, which are generally beyond the correction capabilities of cemented doublets. Therefore, these high-magnification telescopes use a large number of lenses to ensure system aberration correction. This multiple lens configuration leads to lower overall light transmittance, affecting image quality. Furthermore, the optical path alteration in this system is usually achieved using prisms. Light is refracted within the prism, changing its direction. This prism-based refraction method also results in light loss due to transmission and absorption, further impacting transmittance. Moreover, to achieve continuous magnification, this optical system has numerous optical components and a long optical axis. The use of prisms and other components leads to a complex and large system structure, making it unsuitable for applications requiring lightweight and convenient operation. Summary of the Invention

[0005] To address at least one deficiency or improvement requirement of the prior art, the present invention provides a continuously zoom lens-image telescope optical system that can effectively improve the imaging quality of the optical system while effectively shortening the total length of the optical system and reducing the number of lenses.

[0006] To achieve the above object, the application provides a continuously variable zoom lens image conversion telescope optical system, comprising:

[0007] An objective lens, a light path folding assembly, a reticle, a field lens, a first image conversion lens, a second image conversion lens, a diaphragm and an ocular are sequentially arranged along an optical path, wherein,

[0008] The objective lens is a two-piece cemented lens formed by cementing a negative meniscus lens and a double convex lens;

[0009] The light path folding assembly is used for folding the light path and comprises oppositely arranged first and second mirrors, and the light passing through the objective lens cemented lens is reflected by the first and second mirrors in sequence, so that the light path is folded, and then enters the reticle, the field lens, the first image conversion lens, the second image conversion lens, the diaphragm and the ocular in sequence;

[0010] By adjusting one or more of the intervals between the field lens and the first image conversion lens, the interval between the first image conversion lens and the second image conversion lens, and the interval between the second image conversion lens and the diaphragm, the focal length and / or the imaging high-low magnification can be changed.

[0011] As a further improvement of the application, the double convex lens is made of a material with a dispersion rate higher than 70.

[0012] As a further improvement of the application, the double convex lens is made of H-FK61 material.

[0013] As a further improvement of the application, the second mirror is closer to the objective lens than the first mirror, and the light passing through the objective lens is reflected by the first mirror and then incident on the second mirror, so that the optical path length is shortened.

[0014] As a further improvement of the application, the first mirror and the second mirror are both plane mirrors.

[0015] As a further improvement of the application, the optical path length between the objective lens and the ocular is not more than 327.8mm.

[0016] As a further improvement of the application, the focal length varies in the range of 281.7mm-1293.4mm, and the imaging high-low magnification continuously varies in the range of 12.7 times-57.4 times.

[0017] As a further improvement of the application, the first image conversion lens is a cemented lens formed by cementing a negative meniscus lens and a double convex lens; and / or,

[0018] The second lens is a cemented lens formed by cementing a negative meniscus lens and a biconvex lens.

[0019] As a further improvement of the present application, the eyepiece comprises a first eyepiece and a second eyepiece arranged in sequence along the optical path, the first eyepiece is a cemented lens formed by cementing a negative meniscus lens and a biconvex lens; and / or, the second eyepiece is a cemented lens formed by cementing a negative meniscus lens and a biconvex lens.

[0020] As a further improvement of the present application, one or more of the following intervals are adjusted in the range of 52.19-18.02 mm: the interval between the field lens and the first lens; the interval between the first lens and the second lens; and / or the interval between the second lens and the diaphragm.

[0021] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0022] (1) The continuous zoom lens relay telescope optical system provided by the present application adopts a two-piece cemented lens formed by cementing a negative meniscus lens and a biconvex lens as the objective lens, which not only effectively improves the image quality with fewer lenses, but also corrects aberrations with only two cemented lenses to achieve good image quality, and makes the light absorption less and the light transmission better.

[0023] (2) The continuous zoom lens relay telescope optical system provided by the present application adopts a plane mirror combination for the optical path folding component, which not only folds the optical path by reflection, and further improves the light transmission of the system by absorbing less light compared with lenses, but also makes the structure more compact and simple, and is more conducive to reducing the weight and volume of the entire optical system.

[0024] (3) The continuous zoom lens relay telescope optical system provided by the present application adopts an objective lens unit with fewer optical lenses, and the optical path folding component adopts a simple reflecting mirror, which not only makes the entire optical path system have good light transmission and reduces light absorption, but also makes the entire system structure compact and simple, and the size is smaller. By adjusting one or more of the intervals between the field lens and the first lens, the intervals between the first lens and the second lens, and the intervals between the second lens and the diaphragm, the focal length and / or the continuous change of the imaging high and low magnification can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a telescope optical system with continuous magnification in the prior art;

[0027] Figure 2 A schematic diagram of the structure of a lens-image-transfer telescope optical system with continuous magnification provided in one embodiment of this application;

[0028] Figure 3 The field curvature and distortion characteristics of an optical system according to an embodiment of this application are shown in a graph at a variable focal length.

[0029] Figure 4 for Figure 3 The axial aberration curves of the corresponding optical system;

[0030] Figure 5 The field curvature and distortion characteristics of an optical system according to one embodiment of this application are shown in a graph at a different zoom focal length.

[0031] Figure 6 for Figure 5 The axial aberration curves of the corresponding optical system;

[0032] Figure 7 The field curvature and distortion characteristics of an optical system according to an embodiment of this application are shown in the diagram at a third zoom focal length.

[0033] Figure 8 for Figure 7 The corresponding axial aberration curves of the optical system. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The terms "first", "second", "third", and the like in the description and claims of the present application and above figures are used for distinguishing between similar objects and are not necessarily used to describe a particular sequential or chronological order. Also, the terms "comprises", "comprising", "includes", "including", "contains", "containing" or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, includes, contains or contains elements or steps not listed is still within the scope of such terms. For example, a process, method, article, or apparatus that comprises or includes other steps or elements is still within the scope of the present application even if other steps or elements are not listed.

[0036] As shown in Figure 2 The continuous zoom lens relay telescope optical system of the present application comprises, in sequence along the optical path of the optical system, an objective lens 10, a light path folding assembly 20, a grating 30, a field lens 40, a relay first lens 50, a relay second lens 60, a diaphragm 70, an eyepiece 80 and 90, thereby forming the optical device component structure of the entire optical system.

[0037] The objective lens 10 is a two-piece cemented lens formed by a negative meniscus lens 11 and a double convex lens 12. The objective lens 10 in the present application is composed of only two pieces of lens, and the double convex lens 12 is optionally made of low dispersion material, preferably with a dispersion rate higher than 70, for example, a dispersion rate of 70-80, preferably higher than 80, for example, optionally H-FK61 material. Such low dispersion material has excellent achromatic and apochromatic ability. By such double lens cemented composition, on the one hand, the light transmittance is higher than that of the traditional three or more optical lenses, and on the other hand, the complexity and volume weight of the optical system are reduced.

[0038] In an optional embodiment, the left end curvature radius of the negative meniscus lens 11 of the objective lens cemented lens 10 is 178.65 mm, the right end curvature radius is 93.76 mm, and the center thickness is 4 mm. The left end curvature radius of the double convex lens 12 of the objective lens cemented lens 10 is 93.76 mm, the right end curvature radius is -1132.4 mm, and the center thickness is 11 mm.

[0039] As shown in Figure 2 The light path folding assembly 20 of the present application comprises a reflecting mirror 21 and a reflecting mirror 22, wherein the light passing through the objective lens 10 is folded to reduce the optical path length, thereby shortening the length and volume of the entire optical system. Optionally, the reflecting mirror 21 and the reflecting mirror 22 are oppositely arranged, for example, parallel to each other, or other arrangements are also available. The reflecting mirror 21 is closer to the objective lens 10, and the reflecting mirror 22 is farther away from the objective lens 10, so that the light passing through the objective lens 10 is first reflected by the reflecting mirror 21 to fold back and then incident on the reflecting mirror 22 to be emitted again to fold, and then incident on the grating 30 and the subsequent optical devices, thereby minimizing the optical path length.

[0040] Optionally, the mirrors 21 and / or 22 can be plane mirrors, or other types of reflecting devices. The number of mirrors can not be limited to two, but can be one or more, as long as they can be used to fold the optical path and reduce the length of the optical path. The optical path folding assembly of the embodiments of the present application is composed of mirrors, which not only has a small and simple structure, a light volume and size, but also is easy to operate and handle. More importantly, the device does not absorb light relative to other optical path folding devices (such as prisms), so it has a higher light transmittance.

[0041] For example, the central thickness of the mirror 11 can be 5 mm, and the central thickness of the mirror 12 can be 5 mm. For example, the optical axis of the two mirrors is arranged at an angle of 15° and -15° with the normal, respectively.

[0042] As shown in Figure 2 , the folded light passes through the graticule mirror 30 and the field lens 40 in turn. In an optional scheme, the graticule mirror 30 is a plane mirror, and the central thickness thereof can be 3 mm, for example. The field lens 40 is a lens, and the radius of curvature of the left end thereof can be 0 mm, for example, the radius of curvature of the right end thereof can be -43.45 mm, and the central thickness thereof can be 5 mm, for example.

[0043] As shown in Figure 2 , the light after the field lens 40 passes through the image converter lens 50 and the image converter lens 60 in turn. The image converter lens 50 is preferably a cemented lens, which can be formed by cementing a negative meniscus lens 51 and a double convex lens 52, for example. The image converter lens 60 is preferably a cemented lens, which can be formed by cementing a negative meniscus lens 61 and a double convex lens 62, for example.

[0044] In a preferred scheme, at least one of the image converter lens 50 and the image converter lens 60 is movable, i.e., can be operated to move unidirectionally or back and forth along the optical path. For example, the image converter lens 50 and the image converter lens 60 can be separately moved unidirectionally or back and forth along the optical path, or both of them can be simultaneously moved unidirectionally or back and forth along the optical path. By using the above movable mode, the distance D1 between the field lens 40 and the image converter lens 50, the distance D2 between the image converter lens 50 and the image converter lens 60, and the distance D3 between the image converter lens 60 and the diaphragm 70 can be adjusted. For example, in an optional embodiment, D1 can be adjusted in the range of 52.19-18.02 mm, D2 can be adjusted in the range of 24.69-0.86 mm, and D3 can be adjusted in the range of 33.5-91.4 mm. For example, in an optional embodiment, the three distances in the optical system can be set as D1+D2+D3=110.378 mm.

[0045] By adjusting D1, D2, or D3 individually, or by simultaneously adjusting one or more of D1, D2, and D3, the focal length and / or magnification can be varied. Specifically, in an optional embodiment, a movement curve, such as a non-linear movement curve, can be set for the image-shifting lens 50 and the image-shifting lens 60, and a guide curve groove is machined on the zoom tube according to the curve to ensure that the zoom handwheel can rotate smoothly during continuous zooming, thereby changing the values ​​of D1, D2, or D3 to change the focal length and achieve the zoom function. Figures 3-8 The graphs show the field curvature and distortion characteristics at different zoom focal lengths.

[0046] like Figure 2 As shown, the light rays after passing through the image-spinning lens 60 are shaped by the aperture 70 and then enter the eyepiece unit. In one embodiment, the diameter of the aperture 70 can optionally be 17mm, but it can also be other sizes; this solution is not specifically limited.

[0047] In one embodiment, the eyepiece unit includes an eyepiece 80 and an eyepiece 90 arranged sequentially along the optical path, which together constitute the eyepiece unit of the system. Optionally, eyepiece 80 is a cemented lens, formed by cementing a negative meniscus lens 81 and a biconvex lens 82. Optionally, eyepiece 90 is also a cemented lens, formed by cementing a biconvex lens 91 and a negative meniscus lens 92. For example, optionally, the negative meniscus lens 81 of eyepiece 80 has a left-end radius of curvature of 1472 mm, a right-end radius of curvature of 20.7 mm, and a center thickness of 2.5 mm. The biconvex lens 82 of eyepiece 80 has a left-end radius of curvature of 20.7 mm, a right-end radius of curvature of -27.61 mm, and a center thickness of 11 mm. The biconvex lens 91 of eyepiece 90 has a left-end radius of curvature of 26 mm, a right-end radius of curvature of -67.92 mm, and a center thickness of 8 mm. The negative meniscus lens 92 of eyepiece 90 has a left-end radius of curvature of -67.92 mm, a right-end radius of curvature of -88.92 mm, and a center thickness of 2 mm. Of course, the above are merely optional reference examples, and this application does not impose specific limitations on the dimensions and parameters of the eyepiece device.

[0048] On the one hand, by using cemented lenses in both the objective and eyepiece, the overall length of the optical system is effectively shortened and the number of lenses in the optical system is reduced, which enables the entire optical system to achieve a smaller size and weight after assembly.

[0049] In this application, by setting up mirrors 21 and 22 between the objective lens 10 and the reticle 30, which are at a certain angle to the normal, the optical path is refracted, effectively reducing the system length and satisfying the portability of the entire telescope system.

[0050] In this application, all glass surfaces used are spherical, which has the advantages of low production cost, easy processing, easy testing and easy assembly.

[0051] In the present application, the optical system continuous zooming optical system design has great freedom, and the optical system optimization design has many selectable variables, so that the optical system aberration design can easily achieve excellent results and obtain excellent image quality.

[0052] In one specific embodiment of the present application, the focal length of the zoom optical system full system designed by the above structure is 281.7mm (short focus end) to 1293.4mm (long focus end); the magnification of the zoom optical system full system is 12.7 times (short focus end) to 57.4 times (long focus end); F=3.9~17.7, F is the aperture number, which is the reciprocal of the ratio of the entrance pupil diameter to the focal length, i.e. F=f / D; the working waveband range is 450nm~650nm. In the present application, the transfer lens 50 and the transfer lens 60 can realize continuous change of the focal length 281.7mm~1293.4mm and the magnification 12.7 times~57.4 times by moving each other, and the image quality is maintained well during zooming.

[0053] Table 1: Lens parameters of each optical element in the optical system of the embodiment of the present application

[0054]

[0055] During the zooming and focusing process, the transfer lens 50 and the transfer lens 60 move relative to each other to change the interval distance, and the variable interval data is shown in Table 2.

[0056] Table 2: Variable surface interval data

[0057]

[0058] It should be noted that, for the foregoing method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0059] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0060] In several embodiments provided in the present application, it should be understood that the disclosed apparatus can be implemented in other manners. For example, the division of the apparatus embodiments is merely an example, and for example, the division of the units can be different, the units or components can be combined, or some features can be ignored or not executed. In addition, the display or discussion of a relative relationship between the units or the direct or indirect coupling or communication connection between the units should be understood as logical or physical connection or communication connection, and can be implemented in other manners.

[0061] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0062] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0063] The above is only an exemplary embodiment of the present disclosure, and cannot limit the scope of the present disclosure. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure are still within the scope of the present disclosure. Those skilled in the art will easily think of embodiments of the present disclosure after considering the specification and practicing the disclosure herein. The present application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or conventional techniques in the art not described in the present disclosure. The specification and examples are only considered exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0064] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0065] Those skilled in the art will readily understand that the above description is merely of the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A continuously variable power catadioptric telescope optical system, characterized in that, Comprise: consist of an objective lens (10), a light path folding assembly (20), a graticule mirror (30), a field lens (40), a first relay lens (50), a second relay lens (60), a diaphragm (70) and an eyepiece unit (80, 90) arranged in sequence along the light path, wherein, the objective lens (10) is a two-piece cemented positive lens formed by cementing a first negative meniscus lens (11) and a first double convex lens (12); the light path folding assembly (20) is used for light path turning, which consists of oppositely arranged first mirror (22) and second mirror (21), the light passing through the objective lens (10) cemented positive lens is reflected by the first mirror (22) and the second mirror (21) in turn, and then the light path is folded to reduce the light path length, and then enters the graticule mirror (30), the field lens (40), the first relay lens (50), the second relay lens (60), the diaphragm (70) and the eyepiece unit (80, 90) in turn; by adjusting one or more of the distance between the field lens (40) and the first relay lens (50), the distance between the first relay lens (50) and the second relay lens (60), and the distance between the second relay lens (60) and the diaphragm (70) separately or simultaneously, the focal length and / or the imaging high-low magnification change can be realized; wherein the second mirror (21) is closer to the objective lens (10) than the first mirror (22), and the light after the objective lens (10) is reflected by the first mirror (22) and then turns to the second mirror (21), which can shorten the light path length; wherein the first relay lens (50) is a cemented positive lens formed by cementing a second negative meniscus lens (51) and a second double convex lens (52); and, the second relay lens (60) is a cemented positive lens formed by cementing a third negative meniscus lens (61) and a third double convex lens (62); wherein the eyepiece unit (80, 90) consists of a first eyepiece (80) and a second eyepiece (90) arranged in sequence along the light path, the first eyepiece (80) is a cemented positive lens formed by cementing a fourth negative meniscus lens (81) and a fourth double convex lens (82); and, the second eyepiece (90) is a cemented positive lens formed by cementing a fifth double convex lens (91) and a fifth negative meniscus lens (92).

2. The continuously variable power catadioptric telescope optical system of claim 1, wherein, The first double convex lens (12) is made of a material with a dispersion rate higher than 70.

3. The continuously variable power catadioptric telescope optical system of claim 1, wherein, The first double convex lens (12) is made of H-FK61 material.

4. The continuously variable power catadioptric telescope optical system of claim 1, wherein, The first mirror (22) and the second mirror (21) are both plane mirrors.

5. The continuously variable power catadioptric telescope optical system of claim 1, wherein, The light path length between the objective lens (10) and the eyepiece unit (80, 90) is not more than 327.8mm.

6. The continuously variable power catadioptric telescope optical system of claim 1, wherein, The focal length changes in the range of 281.7mm-1293.4mm, and the imaging high-low magnification continuously changes in the range of 12.7 times-57.4 times.

7. The continuously variable magnification lens relay telescope optical system according to claim 1, wherein, the distance between the field lens (40) and the first relay lens (50) is adjusted in the range of 52.19-18.02mm; The distance between the first relay lens (50) and the second relay lens (60) is adjusted in the range of 24.69-0.86mm; and / or One or more of the distances between the second relay lens (60) and the diaphragm (70) is adjusted in the range of 33.5-91.4mm.

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