Switchable visible dual view lens and optical system

Abstract

The application relates to a switchable visible light double-view-field lens and an optical system, which comprises a front fixed lens group, a zoom lens group and a rear fixed lens group; the front fixed lens group and the rear fixed lens group are coaxially distributed along the optical axis direction; the front fixed lens group is used for performing first aberration elimination on light; and the rear fixed lens group is used for performing second aberration elimination on light; the zoom lens group is distributed between the front fixed lens group and the rear fixed lens group and coaxially distributed with the front fixed lens group and the rear fixed lens group; or the zoom lens group avoids the light path between the front fixed lens group and the rear fixed lens group to realize switching from short focus to long focus. The application realizes switching of long focus and short focus modes through rotation design, greatly improves the capturing and continuous tracking capability of the system on a moving target, improves the imaging quality and resolution, simultaneously considers a large aperture and a long focal length, is convenient to use and low in cost.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and more specifically to a switchable visible light dual-field lens and optical system. Background Technology

[0002] A dual-field-of-view optical system is an optical device used for observing distant targets and precisely aiming and magnifying them. It combines the advantages of a short focal length with a wide field of view and large coverage, and a long focal length with a narrow field of view and precise magnification. Light is collected by the lens to correct aberrations before being imaged onto an image sensor. Different magnification levels can be achieved by adjusting the lens spacing. Due to its superior long-distance observation capabilities, it is widely used in military and security fields.

[0003] Currently, designing visible light dual-field-of-view lenses is challenging. The core challenge lies in controlling the slow field-of-view switching speed and aberrations to achieve high-quality imaging and high-resolution targets. This places higher demands on system aberration correction, assembly accuracy, and material stability. Such lenses often use small-aperture lenses, limiting their light-gathering capabilities and significantly reducing the image signal-to-noise ratio in low-light environments, thus affecting observation results. Simultaneously, the relatively short focal length makes it difficult to effectively magnify distant targets, resulting in insufficient detail identification.

[0004] When achieving dual-field switching, existing technologies mostly rely on motor-driven axial adjustment of specific lens intervals, resulting in slow switching speeds that cannot meet the system's dynamic requirements for rapid search and real-time continuous tracking. Summary of the Invention

[0005] This invention addresses the technical problems existing in the prior art by providing a switchable visible light dual-field lens and optical system.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A switchable visible light dual-field lens includes: a front fixed lens group, a zoom lens group, and a rear fixed lens group. The front fixed lens group and the rear fixed lens group are coaxially distributed along the optical axis. The front fixed lens group is used to perform aberration correction on the light first, and the rear fixed lens group is used to perform aberration correction on the light second. The zoom lens group is distributed between the front fixed lens group and the rear fixed lens group, and is coaxially distributed with the front fixed lens group and the rear fixed lens group; or the zoom lens group avoids the optical path between the front fixed lens group and the rear fixed lens group to achieve the switching from short focal length to long focal length.

[0007] The beneficial effects of this invention are as follows: First, the light is aberration-corrected by the front fixed lens group, improving image quality; then, the zoom lens group is used to select between telephoto and short focal length; finally, the image of the object is further aberration-corrected by the rear fixed lens group, further improving image quality, and finally imaged on the photodetector.

[0008] This invention achieves switching between telephoto and short-focal-length modes through a rotating design, which greatly improves the system's ability to capture and continuously track moving targets, while also improving image quality and resolution and accommodating both large aperture and long focal length. It is easy to use and low in cost.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, the zoom lens group includes a cemented doublet lens three and a cemented doublet lens four, which are coaxially distributed; the cemented doublet lens three and the cemented doublet lens four can be distributed between the front fixed lens group and the rear fixed lens group and distributed along the optical axis to be in a short focal length state, or the cemented doublet lens three and the cemented doublet lens four are not on the optical axis to be in a long focal length state.

[0011] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. By using the methods that those skilled in the art can conceive of, the cemented doublet lens three and the cemented doublet lens four are not on the optical axis (long focal length state) or the cemented doublet lens three and the cemented doublet lens four are distributed between the front fixed lens group and the rear fixed lens group and on the optical axis (short focal length state), so as to realize the switching between long focal length and short focal length, which is convenient to use.

[0012] Furthermore, the zoom lens group also includes a rotating device, on which the cemented doublet lens three and the cemented doublet lens four are respectively mounted. The rotating device can drive the cemented doublet lens three and the cemented doublet lens four to rotate around the midpoint of the line connecting the centers of the cemented doublet lens three and the cemented doublet lens four to be horizontally coaxially distributed or vertically coaxially distributed.

[0013] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The rotating device drives the cemented doublet lens three and the cemented doublet lens four to rotate to the vertical coaxial or horizontal coaxial, so as to realize the rapid switching between long focal length and short focal length, and is convenient to use.

[0014] Furthermore, the front fixed lens group includes a first lens and a second lens, the first lens and the second lens are coaxially distributed and coaxially distributed with the zoom lens group, and the second lens is close to the zoom lens group.

[0015] The advantages of adopting the above-mentioned further scheme are that the structure is simple and the design is reasonable. It uses the first lens and the second lens to perform aberration correction on the light rays formed by the object, thereby improving the image quality.

[0016] Furthermore, the front fixed lens group also includes a cemented doublet lens one and a cemented doublet lens two, which are coaxially distributed between the second lens and the zoom lens group, and are also coaxially distributed with the zoom lens group, with the cemented doublet lens one being close to the second lens.

[0017] The advantages of adopting the above-mentioned further scheme are that the structure is simple and the design is reasonable. By using cemented doublet lens one and cemented doublet lens two to further perform aberration correction on the light rays formed by the object, the image quality is further improved.

[0018] Furthermore, the first lens is a biconvex lens with positive optical power, and the second lens is a convex-concave lens with positive optical power, with its convex surface close to the first lens and its concave surface close to the cemented doublet lens. The first cemented doublet lens is a convex-concave lens with negative optical power, including a convex-concave lens with positive optical power and close to the second lens and a convex-concave lens with negative optical power and close to the second cemented doublet lens. The second cemented doublet is a convex-concave lens with positive optical power, including a convex-concave lens with positive optical power that is close to the first cemented doublet and a convex-concave lens with negative optical power that is close to the zoom lens group.

[0019] The advantages of adopting the above-mentioned further scheme are that the structure is simple, the types of the first lens, the second lens, the cemented doublet one and the cemented doublet two are more reasonable, and aberration correction processing can be performed to improve the imaging quality.

[0020] Furthermore, the rear fixed lens group includes a cemented doublet lens five, a third lens, and a cemented doublet lens six. The cemented doublet lens five, the third lens, and the cemented doublet lens six are coaxially distributed in sequence and coaxially distributed with the zoom lens group, and the cemented doublet lens five is close to the zoom lens group.

[0021] The advantages of adopting the above-mentioned further scheme are that the structure is simple and the design is reasonable. By using the fifth, third and sixth cemented doublet lenses to perform aberration correction on the image of the object, the image is clearer and the image quality is guaranteed.

[0022] Furthermore, the rear fixed lens group also includes a fourth lens and a fifth lens, the fourth lens and the fifth lens being coaxially distributed and coaxially distributed with the cemented doublet lens six, and the fourth lens being close to the cemented doublet lens six.

[0023] The advantages of adopting the above-mentioned further scheme are that the structure is simple and the design is reasonable. The fourth and fifth lenses are used to further perform aberration correction on the image of the object, and at the same time, magnification is performed to make the image clearer and ensure the image quality.

[0024] Furthermore, the cemented doublet lens five is a convex-concave lens with negative optical power, including a biconvex lens with positive optical power and close to the zoom lens group and a biconcave lens with negative optical power and close to the third lens. The cemented doublet lens six is ​​a convex-concave lens with positive optical power, including a convex-concave lens with negative optical power and close to the third lens and a convex-concave lens with positive optical power and close to the fourth lens. The third lens is a convex-concave lens with positive optical power, its convex surface is close to the cemented doublet five, and its concave surface is close to the cemented doublet six; The fourth lens is a biconcave lens with negative optical power, and the fifth lens is a biconvex lens with positive optical power.

[0025] The advantages of adopting the above-mentioned further scheme are that the structure is simple, and the types of the third lens, fourth lens, fifth lens, cemented doublet five and cemented doublet six are more reasonable, which can perform aberration correction on the light rays formed by the object and improve the imaging quality.

[0026] The present invention also relates to an optical system comprising a switchable visible light dual-field lens as described above.

[0027] The beneficial effect of adopting the above-mentioned further solutions is that the present invention also provides an optical system that achieves switching between long focal length and short focal length modes through a rotation design, which greatly improves the system's ability to capture and continuously track moving targets, improves imaging quality and resolution, and simultaneously takes into account large aperture and long focal length. It is convenient to use and low in cost. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the lens structure in this invention; Figure 2 This is a dot plot of the telephoto (700mm) focal length in this invention; Figure 3 This is a field curvature distortion diagram at the telephoto (700mm) focal length in this invention; Figure 4 This is the full-field modulation transfer function (MTF) plot for a telephoto lens (700mm) with a resolution of 50lp / mm in this invention. Figure 5 This is the relative illumination diagram of the entire field of view at the telephoto (700mm) in this invention; Figure 6 This is a dot plot of the short focal length (380mm) in this invention; Figure 7 This is a field curvature distortion diagram for short focal length (380mm) in this invention; Figure 8 This is the full-field modulation transfer function (MTF) plot for a short focal length (380mm) and a resolution of 50lp / mm in this invention. Figure 9 This is a relative illumination diagram of the entire field of view at a short focal length (380mm) in this invention.

[0029] The attached diagram lists the components represented by each number as follows: 100. Front fixed lens group; 110. First lens; 120. Second lens; 130. Cemented doublet lens one; 140. Cemented doublet lens two; 200. Zoom lens group; 210. Cemented doublet lens three; 220. Cemented doublet lens four; 230. Rotating device; 300. Aperture stop; 400. Rear fixed lens group; 410. Cemented doublet lens five; 420. Third lens; 430. Cemented doublet lens six; 440. Fourth lens; 450. Fifth lens; 500. Photodetector. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the description of this application, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0033] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0034] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0035] Example 1 like Figures 1 to 9 As shown, this embodiment provides a switchable visible light dual-field lens, including: a front fixed lens group 100, a zoom lens group 200, and a rear fixed lens group 400. The front fixed lens group 100 and the rear fixed lens group 400 are coaxially distributed along the optical axis. The front fixed lens group 100 is used to perform aberration correction on the light once, and the rear fixed lens group 400 is used to perform aberration correction on the light again. The zoom lens group 200 is distributed between the front fixed lens group 100 and the rear fixed lens group 400, and is coaxially distributed with the front fixed lens group 100 and the rear fixed lens group 400; or the zoom lens group 200 avoids the optical path between the front fixed lens group 100 and the rear fixed lens group 400, so as to realize the switching from short focal length to long focal length.

[0036] First, the front fixed lens group 100 performs aberration correction on the light rays formed by the object to improve image quality; then, the zoom lens group 200 selects and switches between telephoto and short focal length; finally, the rear fixed lens group 400 further performs aberration correction on the image of the object to further improve image quality, and finally images the image onto the photodetector 500.

[0037] Preferably, in this embodiment, the aperture 300 is distributed between the zoom lens group 200 and the rear fixed lens group 400.

[0038] In addition, a photodetector 500 is provided on the side of the aforementioned rear fixed lens group 400 away from the zoom lens group 200, and the final image is formed on the photodetector 500.

[0039] This embodiment achieves switching between telephoto and short-focal-length modes through a rotating design, which greatly enhances the system's ability to capture and continuously track moving targets, improves image quality and resolution, and simultaneously accommodates large aperture and long focal length. It is easy to use and low in cost.

[0040] Example 2 Based on Embodiment 1, in this embodiment, the zoom lens group 200 includes a cemented doublet lens 210 and a cemented doublet lens 220, which are coaxially distributed. The cemented doublet lens 210 and the cemented doublet lens 220 can be distributed between the front fixed lens group 100 and the rear fixed lens group 400, and distributed along the optical axis to be in a short focal length state, or the cemented doublet lens 210 and the cemented doublet lens 220 are not on the optical axis to be in a long focal length state.

[0041] This solution has a simple structure and a reasonable design. It utilizes methods that those skilled in the art can conceive of to make the cemented doublet lens 3 210 and the cemented doublet lens 4 220 not on the optical axis (long focal length state) or to make the cemented doublet lens 3 210 and the cemented doublet lens 4 220 distributed between the front fixed lens group 100 and the rear fixed lens group 400 and on the optical axis (short focal length state), thereby realizing the switching between long focal length and short focal length, which is convenient to use.

[0042] Example 3 Based on Embodiment 2, in this embodiment, the zoom lens group 200 further includes a rotating device 230. The cemented doublet lens 3 210 and the cemented doublet lens 4 220 are respectively mounted on the rotating device 230. The rotating device 230 can drive the cemented doublet lens 3 210 and the cemented doublet lens 4 220 to rotate around the midpoint of the line connecting the centers of the cemented doublet lens 3 210 and the cemented doublet lens 4 220 to a horizontally coaxial or vertically coaxial distribution.

[0043] The scheme has a simple structure and reasonable design. It uses a rotating device 230 to drive the cemented doublet lens 3 210 and the cemented doublet lens 4 220 to rotate to vertical coaxial (telephoto mode) or horizontal coaxial (shortphoto mode), so as to achieve rapid switching between telephoto and shortphoto modes and make it easy to use.

[0044] Preferably, in this embodiment, the rotating device 230 can be a rotary motor, with a mounting plate fixedly connected to the drive end of the rotary motor. The cemented doublet lens 210 and the cemented doublet lens 220 are respectively mounted on the mounting plate. In use, the rotary motor drives the mounting plate and the cemented doublet lens 210 and the cemented doublet lens 220 thereon to rotate.

[0045] Alternatively, the positions of the cemented doublet lens 3 210 and the cemented doublet lens 4 220 can be changed in other ways to achieve rapid switching between telephoto and short focal lengths, for example: Option 1: The cemented doublet lens 3 210 and the cemented doublet lens 4 220 are distributed between the front fixed lens group 100 and the rear fixed lens group 400, and are distributed along the optical axis. The cemented doublet lens 3 210 and the cemented doublet lens 4 220 are detachable and are in short focal length mode. When it is necessary to switch to long focal length mode, the cemented doublet lens 3 210 and the cemented doublet lens 4 220 can be removed.

[0046] Option 2: Replace the rotating device 230 with a telescopic device. For example, the telescopic device includes a telescopic cylinder, which is fixedly installed. Its telescopic end extends and retracts in a direction perpendicular to the optical axis and is fixedly connected to a mounting plate. The cemented doublet lens 210 and the cemented doublet lens 220 are respectively mounted on the mounting plate. In use, the telescopic cylinder extends and retracts to move the mounting plate and the cemented doublet lens 210 and the cemented doublet lens 220 on it to the area between the front fixed lens group 100 and the rear fixed lens group 400, and they are distributed along the optical axis, at which point they are in a short focal length state; or, the telescopic cylinder extends and retracts to move the mounting plate and the cemented doublet lens 210 and the cemented doublet lens 220 on it to an area outside the area between the front fixed lens group 100 and the rear fixed lens group 400, at which point they are in a long focal length state.

[0047] Example 4 Based on the above embodiments, in this embodiment, the front fixed lens group 100 includes a first lens 110 and a second lens 120. The first lens 110 and the second lens 120 are coaxially distributed and coaxially distributed with the zoom lens group 200, and the second lens 120 is close to the zoom lens group 200.

[0048] The scheme has a simple structure and reasonable design. It uses the first lens 110 and the second lens 120 to perform aberration correction on the light rays formed by the object, thereby improving image quality.

[0049] Example 5 Based on Embodiment 4, in this embodiment, the front fixed lens group 100 further includes a cemented doublet lens 130 and a cemented doublet lens 140. The cemented doublet lens 130 and the cemented doublet lens 140 are coaxially distributed between the second lens 120 and the zoom lens group 200, and are coaxially distributed with the zoom lens group 200. The cemented doublet lens 130 is close to the second lens 120.

[0050] The scheme has a simple structure and reasonable design. It uses cemented doublet lens 130 and cemented doublet lens 240 to further aberration-correct the light rays formed by the object, thereby further improving the image quality.

[0051] Example 6 Based on embodiment 5, in this embodiment, the first lens 110 is a biconvex lens with positive optical power, and the second lens 120 is a convex-concave lens with positive optical power, with its convex surface close to the first lens 110 and its concave surface close to the cemented doublet lens 130. The cemented doublet lens 130 is a convex-concave lens with negative optical power, including a convex-concave lens with positive optical power and close to the second lens 120 and a convex-concave lens with negative optical power and close to the cemented doublet lens 140. The second cemented doublet lens 140 is a convex-concave lens with positive optical power, including a convex-concave lens with positive optical power that is close to the first cemented doublet lens 130 and a convex-concave lens with negative optical power that is close to the zoom lens group 200.

[0052] The scheme has a simple structure, and the types of the first lens 110, the second lens 120, the cemented doublet 130 and the cemented doublet 2 140 are relatively reasonable, which can perform aberration correction and improve imaging quality.

[0053] Example 7 Based on the above embodiments, in this embodiment, the rear fixed lens group 400 includes a cemented doublet lens 410, a third lens 420, and a cemented doublet lens 430. The cemented doublet lens 410, the third lens 420, and the cemented doublet lens 430 are coaxially distributed in sequence and coaxially distributed with the zoom lens group 200, and the cemented doublet lens 410 is close to the zoom lens group 200.

[0054] The scheme has a simple structure and reasonable design. It uses cemented doublet lens 410, third lens 420 and cemented doublet lens 430 to perform aberration correction on the image of the object, making the image clearer and ensuring the quality of the image.

[0055] Example 8 Based on Embodiment 7, in this embodiment, the rear fixed lens group 400 further includes a fourth lens 440 and a fifth lens 450. The fourth lens 440 and the fifth lens 450 are coaxially distributed and coaxially distributed with the cemented doublet lens 430, and the fourth lens 440 is close to the cemented doublet lens 430.

[0056] The scheme has a simple structure and reasonable design. It uses the fourth lens 440 and the fifth lens 450 to further perform aberration correction on the image of the object, making the image clearer and ensuring the image quality.

[0057] Example 9 Based on embodiment 8, in this embodiment, the doublet lens 410 is a convex-concave lens with negative optical power, including a biconvex lens with positive optical power and close to the zoom lens group 200 and a biconcave lens with negative optical power and close to the third lens 420. The doublet lens 430 is a convex-concave lens with positive optical power, including a convex-concave lens with negative optical power and close to the third lens 420 and a convex-concave lens with positive optical power and close to the fourth lens 440. The third lens 420 is a convex-concave lens with positive optical power, its convex surface is close to the cemented doublet 410, and its concave surface is close to the cemented doublet 430. The fourth lens 440 is a biconcave lens with negative optical power, and the fifth lens 450 is a biconvex lens with positive optical power.

[0058] The scheme has a simple structure, and the types of cemented doublet lens 410, third lens 420, cemented doublet lens 430, fourth lens 440 and fifth lens 450 are relatively reasonable. They can perform aberration correction on the light rays formed by the object and improve the image quality.

[0059] Preferably, in this embodiment, the lenses of the front fixed lens group 100, the zoom lens group 200, and the rear fixed lens group 400 are all spherical glass lenses.

[0060] Example 10 Based on the above embodiments, this embodiment also provides an optical system, including the switchable visible light dual-field lens as described above.

[0061] This embodiment also provides an optical system that achieves switching between telephoto and short-focal-length modes through a rotational design, greatly improving the system's ability to capture and continuously track moving targets, while also improving image quality and resolution and accommodating both large aperture and long focal length. It is easy to use and low in cost.

[0062] This invention provides a switchable visible light dual-field lens and optical system, the operating principle of which is as follows: First, the front fixed lens group 100 performs aberration correction on the light rays formed by the object; then, the zoom lens group 200 selects and switches between telephoto and short focal length; finally, the rear fixed lens group 400 further performs aberration correction on the image of the object, thereby further improving image quality.

[0063] The front fixed lens group 100 extends from the object side to the image side (i.e., attached) Figure 1 From left to right in the image, the lenses are a first lens 110, a second lens 120, a cemented doublet 130, and a cemented doublet 140, which perform preliminary aberration correction on the light and set a larger aperture to improve imaging resolution and imaging quality.

[0064] Light passes sequentially through the zoom lens group, including cemented doublet 3 210 and cemented doublet 4 220. The two lenses are quickly cut out by rotating the rotating device 230 by 90° to achieve the telephoto (700mm) mode, and vice versa for the short focal length (380mm) mode.

[0065] The rear fixed lens assembly 400 extends from the object side to the image side (i.e., the attached lens assembly). Figure 1 From left to right in the image, the lenses are: cemented doublet 410, third lens 420, cemented doublet 430, fourth lens 440, and fifth lens 450, which are ultimately imaged onto photodetector 500. This achieves rapid switching between long and short focal lengths and high-resolution imaging, while also possessing a larger aperture and a longer focal length.

[0066] It should be noted that the appendix Figure 1 The dashed box in the image represents zoom lens group 200 after being rotated 90°.

[0067] Figure 2 This is a dot plot of the telephoto (700mm) lens in an embodiment of the present invention. For example... Figure 2 As shown, the RMS spot radius across the entire field of view is <8.5μm, and the GEO spot radius is <12μm. The image quality is good at long focal lengths, which is beneficial for quickly locating and observing targets.

[0068] Figure 3 This is a field curvature distortion diagram of the entire field of view at a telephoto (700mm) according to an embodiment of the present invention. For example... Figure 3 As shown, at telephoto lenses, the field curvature across the entire field of view is <0.1mm, and the distortion is <0.4%. This is beneficial for improving the stability of the observation process.

[0069] Figure 4 This is the full-field modulation transfer function (MTF) diagram of the telephoto (700mm) lens in an embodiment of the present invention at a resolution of 50lp / mm. For example... Figure 4 As shown, the full-field optical modulation transfer function (MTF) is ≥0.5 at a spatial frequency of 50 lp / mm. The image quality is good at long focal lengths, which is beneficial for rapid target localization and observation stability.

[0070] Figure 5 This is a relative illumination diagram of the entire field of view at a telephoto (700mm) according to an embodiment of the present invention. For example... Figure 5 As shown, the relative illumination across the entire field of view is >0.85 at the telephoto (700mm) focal length. Increasing the illumination at the edge of the field of view is beneficial for observing and locating targets.

[0071] Figure 6 This is a dot plot of the short focal length (380mm) according to an embodiment of the present invention. For example... Figure 6 As shown, the RMS spot radius across the entire field of view is <5μm, and the GEO spot radius is <24μm. Good image quality is achieved at short focal lengths, which is beneficial for rapid target searching.

[0072] Figure 7 This is a field curvature and distortion diagram of the short focal length (380mm) full field of view and full wavelength of an embodiment of the present invention. For example... Figure 7 As shown, the field curvature is ≤0.16mm and the distortion is ≤0.3%. The short focal length results in less distortion, which improves the stability of observation.

[0073] Figure 8 This is the full-field modulation transfer function (MTF) diagram of the present invention at a resolution of 50 lp / mm for a short focal length (380 mm), as shown in the embodiment. Figure 8 As shown, the full-field optical modulation transfer function (MTF) is ≥0.55 at a spatial frequency of 50 lp / mm. This is beneficial for quickly locating the observation target and improving observation stability.

[0074] Figure 9 This is a relative illumination diagram of the entire field of view in a short focal length (380mm) embodiment of the present invention. For example... Figure 9 As shown, the relative illumination across the entire field of view is >0.92 at a short focal length (380mm). This improves the illumination at the edge of the field of view, which is beneficial for searching and locating targets.

[0075] In this embodiment of the invention, the distortion of the dual-field-of-view lens is ≤0.4%.

[0076] In this embodiment of the invention, the short focal length of the dual-field-of-view lens is ≤380mm.

[0077] In this embodiment of the invention, the focal length of the dual-field-of-view lens is ≥700mm.

[0078] This invention provides a switchable visible light dual-field lens and optical system, which achieves switching between telephoto and short-focal-length modes through a rotating design, greatly improving the system's ability to capture and continuously track moving targets, while also improving image quality and resolution and accommodating both large aperture and long focal length. It is easy to use and low in cost.

[0079] Compared with the prior art, the beneficial effects of the present invention are: This invention presents a global visible light dual-field optical system that uses mechanical structure rotation to switch between telephoto and short-focal-length modes, greatly improving the system's ability to capture and continuously track moving targets.

[0080] The global aperture design effectively reduces processing difficulty and manufacturing costs. Careful optical path design and aberration optimization effectively improve image quality and resolution, enriching image details; and combined with a larger aperture, it enhances the system's light-gathering capability and increases field-of-view brightness.

[0081] In summary, this embodiment effectively balances performance and cost. It achieves rapid switching between dual fields of view without using aspherical lenses, improving image quality and resolution while simultaneously accommodating a large aperture and long focal length.

[0082] This invention addresses the shortcomings of existing visible light dual-field-of-view lenses, primarily solving the following technical problems: 1) Overcoming the drawback of slow switching speed of traditional field of view axis, this embodiment uses a rotation method to achieve rapid switching from short focal length to long focal length mode; 2) Improved imaging resolution. This embodiment further improves imaging resolution and image quality by increasing the lens aperture and optimizing aberration control.

[0083] In view of the above-mentioned defects in the current technology, the purpose of this invention is to provide a high-resolution visible light dual-field lens that can be quickly switched, and can simultaneously achieve the goals of large aperture and long focal length.

[0084] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A switchable visible light dual-field lens, characterized in that, include: The system comprises a front fixed lens group (100), a zoom lens group (200), and a rear fixed lens group (400). The front fixed lens group (100) and the rear fixed lens group (400) are coaxially distributed at intervals along the optical axis. The front fixed lens group (100) is used to perform aberration correction on the light beam, and the rear fixed lens group (400) is used to perform aberration correction on the light beam again. The zoom lens group (200) is distributed between the front fixed lens group (100) and the rear fixed lens group (400), and is coaxially distributed with the front fixed lens group (100) and the rear fixed lens group (400); or the zoom lens group (200) avoids the optical path between the front fixed lens group (100) and the rear fixed lens group (400) to achieve the switching from short focal length to long focal length.

2. The switchable visible light dual-field lens according to claim 1, characterized in that, The zoom lens group (200) includes a cemented doublet lens three (210) and a cemented doublet lens four (220), which are coaxially distributed. The cemented doublet lens three (210) and the cemented doublet lens four (220) can be distributed between the front fixed lens group (100) and the rear fixed lens group (400) and distributed along the optical axis to be in a short focal length state, or the cemented doublet lens three (210) and the cemented doublet lens four (220) are not on the optical axis to be in a long focal length state.

3. The switchable visible light dual-field lens according to claim 2, characterized in that, The zoom lens group (200) also includes a rotating device (230). The cemented doublet lens three (210) and the cemented doublet lens four (220) are respectively mounted on the rotating device (230). The rotating device (230) can drive the cemented doublet lens three (210) and the cemented doublet lens four (220) to rotate around the midpoint of the line connecting the centers of the cemented doublet lens three (210) and the cemented doublet lens four (220) to be horizontally coaxially distributed or vertically coaxially distributed.

4. The switchable visible light dual-field lens according to any one of claims 1-3, characterized in that, The front fixed lens group (100) includes a first lens (110) and a second lens (120), the first lens (110) and the second lens (120) are coaxially distributed and coaxially distributed with the zoom lens group (200), and the second lens (120) is close to the zoom lens group (200).

5. The switchable visible light dual-field lens according to claim 4, characterized in that, The front fixed lens group (100) further includes a cemented doublet lens one (130) and a cemented doublet lens two (140), which are coaxially distributed between the second lens (120) and the zoom lens group (200), and are coaxially distributed with the zoom lens group (200), and the cemented doublet lens one (130) is close to the second lens (120).

6. The switchable visible light dual-field lens according to claim 5, characterized in that, The first lens (110) is a biconvex lens with positive optical power, and the second lens (120) is a convex-concave lens with positive optical power, with its convex surface close to the first lens (110) and its concave surface close to the first cemented doublet lens (130). The first cemented doublet lens (130) is a convex-concave lens with negative optical power, including a convex-concave lens with positive optical power and close to the second lens (120) and a convex-concave lens with negative optical power and close to the second cemented doublet lens (140). The second cemented doublet (140) is a convex-concave lens with positive optical power, including a convex-concave lens with positive optical power that is close to the first cemented doublet (130) and a convex-concave lens with negative optical power that is close to the zoom lens group (200).

7. The switchable visible light dual-field lens according to any one of claims 1-3, characterized in that, The rear fixed lens group (400) includes a cemented doublet lens five (410), a third lens (420), and a cemented doublet lens six (430). The cemented doublet lens five (410), the third lens (420), and the cemented doublet lens six (430) are coaxially distributed in sequence and coaxially distributed with the zoom lens group (200), and the cemented doublet lens five (410) is close to the zoom lens group (200).

8. The switchable visible light dual-field lens according to claim 7, characterized in that, The rear fixed lens group (400) further includes a fourth lens (440) and a fifth lens (450), the fourth lens (440) and the fifth lens (450) being coaxially distributed and coaxially distributed with the cemented doublet lens six (430), and the fourth lens (440) being close to the cemented doublet lens six (430).

9. The switchable visible light dual-field lens according to claim 8, characterized in that, The doublet lens five (410) is a convex-concave lens with negative optical power, including a biconvex lens with positive optical power and close to the zoom lens group (200) and a biconcave lens with negative optical power and close to the third lens (420). The doublet lens six (430) is a convex-concave lens with positive optical power, including a convex-concave lens with negative optical power and close to the third lens (420) and a convex-concave lens with positive optical power and close to the fourth lens (440). The third lens (420) is a convex-concave lens with positive optical power, its convex surface is close to the cemented doublet five (410), and its concave surface is close to the cemented doublet six (430). The fourth lens (440) is a biconcave lens with negative optical power, and the fifth lens (450) is a biconvex lens with positive optical power.

10. An optical system, characterized in that, Including the switchable visible light dual-field lens as described in any one of claims 1-9.

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