Day / night switching scope optics system

Abstract

This application relates to the field of optical instrument technology, and in particular to an optical system for a day / night switching sight, comprising an objective lens group, an image-rotating mirror group, and an eyepiece group arranged sequentially along the optical path, as well as a reticle and an optoelectronic imaging module. The reticle and the optoelectronic imaging module are configured to be selectively moved into the optical path between the objective lens group and the image-rotating mirror group. The optoelectronic imaging module is used to capture light signals and display images. The system also includes a switching unit, which is mechanically connected to the reticle and the optoelectronic imaging module, and is used to drive the reticle or the optoelectronic imaging module into the optical path to achieve switching between visible light aiming mode and low light aiming mode. This allows the user to see a clear and stable target image in bright daylight or in complete darkness, enabling precise aiming.

Description

Technical Field

[0001] This application relates to the field of optical instrument technology, and in particular to an optical system for a day / night switching sight. Background Technology

[0002] Currently, optical instruments are increasingly used in fields such as security and hunting, as well as in scenarios with special requirements such as geographic surveying, architectural photography, and others. White light sights are aiming devices that utilize natural light and image formation through optical systems such as lenses and prisms. The main problem with existing white light sights is their inability to function effectively both day and night; at night, they must be switched to dedicated night vision equipment. Furthermore, night vision equipment is bulky, consumes a lot of power, and requires complex operation for quick switching in field conditions, severely impacting continuous operational capability.

[0003] Currently, commonly used white light gun sights are usually based on the optical system principle of Kepler telescopes. These sights rely solely on visible light for imaging and can only be used in daylight or bright nighttime environments. In nighttime or completely dark environments, they must be manually switched to night vision gun sights, which is cumbersome and makes it easy to lose the target. Summary of the Invention

[0004] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This part of the invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] In view of this, an optical system for a day / night switching sight is proposed according to an embodiment of this application, comprising: The objective lens group, the image-rotating mirror group, and the eyepiece group are arranged sequentially along the optical path; A reticle and an optoelectronic imaging module are configured to be selectively moved into the optical path between the objective lens group and the rotating mirror group. The optoelectronic imaging module is used to capture light signals and display images. A switching unit is mechanically connected to the reticle and the photoelectric imaging module, and is used to drive the reticle or the photoelectric imaging module to enter the optical path to realize the switching between visible light observation mode and micro light observation mode.

[0007] In one feasible implementation, the photoelectric imaging module includes: An image sensing element is disposed on the image side of the objective lens group, and is used to receive light signals from the objective lens group and output electrical signals; An image display element is disposed on the object side of the rotating mirror assembly. The image display element is electrically connected to the image sensing element and is used to receive the electrical signal and display the image.

[0008] In one feasible implementation, in the visible light viewing mode, the system's spectral transmission range is 486nm~656nm, the magnification is not less than 3 times, the field of view is not less than 10°, the entrance pupil diameter is not less than 15mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

[0009] In one feasible implementation, in the low-light observation mode, the system's spectral transmission range is 480nm~900nm, the magnification is not less than 3 times, the field of view is not less than 15.6°, the entrance pupil diameter is not less than 50mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

[0010] In one feasible implementation, the objective lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical path, with the entrance pupil of the system located on the frame of the first lens. The first lens has a crown glass lens, and the optical power of the first lens is positive; The second lens has a barium flint glass lens, and the optical power of the second lens is positive; The third lens has a heavy flint glass lens, and the optical power of the third lens is negative. The fourth lens has a lanthanum crown glass lens, and the optical power of the fourth lens is positive. The fifth lens has a lanthanum flint glass lens, and the optical power of the fifth lens is positive. The sixth lens has a crown glass lens and has a negative optical power.

[0011] In one feasible implementation, in the visible light viewing mode, the focal length of the objective lens group is not less than 60mm, the field of view is not less than 10°, and the entrance pupil diameter is not less than 15mm.

[0012] In one feasible implementation, in the low-light observation mode, the focal length of the objective lens group is not less than 60mm, the field of view is not less than 15.6°, and the entrance pupil diameter is not less than 50mm.

[0013] In one feasible implementation, the image-rotating mirror group includes a seventh lens, a cemented lens, a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially along the optical path, and the magnification of the image-rotating mirror group is -1x; The seventh lens has a lanthanum flint glass lens, and the optical power of the seventh lens is positive. The cemented lens includes a crown glass lens and a heavy flint glass lens, wherein the optical power of the crown glass lens is positive and the optical power of the heavy flint glass lens is negative. The tenth lens has a lanthanum crown glass lens, and the optical power of the tenth lens is positive. The eleventh lens has a lanthanum flint glass lens, and the optical power of the eleventh lens is positive. The twelfth lens has a crown glass lens and a negative optical power.

[0014] In one feasible implementation, the eyepiece group includes a thirteenth lens and a fourteenth lens arranged sequentially along the optical path; The thirteenth lens has a barium flint glass lens, and the optical power of the thirteenth lens is positive. The fourteenth lens has a low-dispersion light crown glass lens, and the optical power of the fourteenth lens is positive.

[0015] In one feasible implementation, the focal length of the eyepiece group is not less than 20mm, the relative aperture is not less than 4, the exit pupil distance is not less than 25mm, and the exit pupil diameter is not less than 5mm.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The day / night switching aiming scope optical system provided in this application includes an objective lens group, an image-rotating lens group, and an eyepiece group arranged sequentially along the optical path, as well as a reticle and an optoelectronic imaging module. The reticle and optoelectronic imaging module are configured to be selectively moved into the optical path between the objective lens group and the image-rotating lens group. The optoelectronic imaging module is used to capture light signals and display images. The system also includes a switching unit, which is mechanically connected to the reticle and the optoelectronic imaging module. The switching unit is used to drive the reticle or the optoelectronic imaging module to enter the optical path to realize the switching between visible light aiming mode and low light aiming mode. It can present clear and stable target images to the user in bright daylight or pitch black night, and achieve accurate aiming.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1A schematic structural diagram of a day / night switching sight optical system in visible light mode, according to an embodiment of this application; Figure 2 This is a schematic structural diagram of a day / night switching sight optical system in low-light mode, according to an embodiment of this application.

[0019] in, Figure 1 and Figure 2 The correspondence between the reference numerals and component names in the attached drawings is as follows: 1. Objective lens group; 2. Photoelectric imaging module; 3. Reticle; 4. Image rotating mirror group; 5. Eyepiece group. Detailed Implementation

[0020] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the technical solutions provided by the present invention. However, it will be apparent to those skilled in the art that the technical solutions provided by the present invention can be implemented without one or more of these details.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0022] Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the invention is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0023] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0024] like Figure 1 and Figure 2As shown in the embodiment of this application, a day / night switching aiming scope optical system is proposed, including an objective lens group 1, an image-rotating mirror group 4, and an eyepiece group 5 arranged sequentially along the optical path, as well as a reticle 3 and an optoelectronic imaging module 2. The reticle 3 and the optoelectronic imaging module 2 are configured to be selectively moved into the optical path between the objective lens group 1 and the image-rotating mirror group 4. The optoelectronic imaging module 2 is used to capture light signals and display images. The system also includes a switching unit, which is mechanically connected to the reticle 3 and the optoelectronic imaging module 2, and is used to drive the reticle 3 or the optoelectronic imaging module 2 into the optical path to realize the switching between visible light aiming mode and low light aiming mode. In the visible light viewing mode, the incident light is converged by the objective lens group 1 to the reticle 3 to form a primary inverted image, then passed through the image-rotating mirror group 4 to form a secondary upright image, and finally observed through the eyepiece group 5. In the low-light viewing mode, the incident light is converged by the objective lens group 1 and captured and displayed by the photoelectric imaging module 2 to form a primary inverted image. This primary inverted image is then passed through the image-rotating mirror group 4 to form a secondary upright image, and finally observed through the eyepiece group 5. Sufficient air gap is reserved between the objective lens group 1 and the image-rotating mirror group 4 to allow sufficient movement space for the reticle 3 and the photoelectric imaging module 2 to be inserted / exited. The photoelectric imaging module 2 can be a CCD / OLED integrated mechanism. The reticle 3 is a high-gloss flat glass plate with twelve-figure reticle lines. The twelve-figure reticle lines can be etched into different shapes according to actual needs, but the minimum scale interval should meet the minimum resolution requirements of the human eye. This invention adopts an internal focusing structure with good sealing performance. The rapid switching between the reticle 3 and the integrated mechanism can be easily achieved through the mechanical structure, thereby achieving rapid switching between day and night visible light / low light observation modes.

[0025] In this technical solution, the day / night switching sight optical system also includes a scope barrel, with the objective lens group 1, image-rotating mirror group 4, eyepiece group 5, reticle 3, and photoelectric imaging module 2 all housed within the scope barrel. One specific implementation of the switching unit can employ a rotary lever structure. This lever is fixed to the scope barrel via a rotating shaft. Both ends of the lever have slots for holding the reticle 3 and photoelectric imaging module 2. When the operator moves the lever, one end causes the reticle 3 to engage the optical path, while the other end causes the photoelectric imaging module 2 to disengage from the optical path, and vice versa. The entire process is completed with a single action, ensuring synchronous switching. Another implementation uses a sliding push rod. The push rod is connected to a slider with two parallel guide grooves. The reticle 3 and photoelectric imaging module 2 are mounted on two independent slide blocks, which are embedded in the guide grooves. When the push rod slides back and forth, a linkage mechanism drives one slide block to engage the optical path while the other slide block disengages. This linear switching method is compact and occupies little space. Another implementation method can be an electromagnetic drive. Two miniature electromagnets are set up to control the locking and releasing of the reticle 3 and the photoelectric imaging module 2 respectively. When the switching signal is triggered, one electromagnet is de-energized to release the corresponding component, while the other electromagnet is energized to lock the other component. The component is switched in and out by a spring reset mechanism. This method can realize remote or automatic control.

[0026] Understandably, this design, which allows for selective movement of the reticle 3 and the electro-optical imaging module 2 via a switching unit, ensures the speed and reliability of switching between day and night observation modes. Whether using a mechanical lever, a sliding push rod, or an electromagnetic drive, the interchange of the two components is completed with a single action, avoiding cumbersome manual replacement operations and significantly shortening the mode switching time. The reserved air gap provides ample space for movement during the switching process, preventing collisions between the components and the optical lenses during movement and ensuring the system's stability and durability. This modular switching design not only simplifies the system structure but also improves overall sealing and environmental adaptability. Combined with the internal focusing structure, it allows the scope to maintain stable operation in various complex environments.

[0027] In one feasible implementation, the photoelectric imaging module 2 includes an image sensing element and an image display element. The image sensing element is disposed on the image side of the objective lens group 1 and is used to receive light signals from the objective lens group 1 and output electrical signals. The image display element is disposed on the object side of the rotating mirror group 4 and is electrically connected to the image sensing element, and is used to receive electrical signals and display images.

[0028] In this technical solution, the image sensing element can be a CCD sensor, and the image display element can be an OLED display. The integrated CCD / OLED module uses a low-light CCD module with a target surface size of 1 inch, an effective pixel size of 1152×864 (horizontal×vertical), and a pixel size of 13 micrometers×13 micrometers, and an OLED display with an effective pixel size of 1024×768 and a pixel size of 12 micrometers×12 micrometers.

[0029] Understandably, this design, which separates the image sensing element and the image display element, provides greater flexibility in the configuration of the optoelectronic imaging module 2, allowing for optimized combinations based on different application scenarios and cost requirements. Positioning the sensor on the object mirror side maximizes the reception of converged, weak light signals, ensuring imaging quality in low-light mode. Meanwhile, placing the display on the object mirror side ensures that the displayed image can be correctly imaged by the subsequent optical system and ultimately presented to the observer. This structural design not only guarantees imaging quality in low-light mode but also allows the entire optoelectronic imaging module 2 to be quickly replaced as an independent unit, perfectly complementing the switching mechanism of the reticle 3 and achieving seamless transition between day and night modes.

[0030] In one feasible implementation, in visible light viewing mode, the system's spectral transmission range is 486nm~656nm, the magnification is not less than 3 times, the field of view is not less than 10°, the entrance pupil diameter is not less than 15mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

[0031] In this technical solution, to achieve a spectral transmission range of 486nm~656nm, a visible light band antireflection coating can be deposited on the surface of each lens. For example, a MgF2 / SiO2 multilayer film system can be used, achieving a transmittance of greater than 99% at the center wavelength of 550nm, effectively reducing reflection loss in this band. A magnification of 3x can be achieved by matching the objective lens group 1 (at least 60mm) with the eyepiece group 5 (focal length 19.98mm). A field of view of 10° is ensured by limiting the aperture position and lens diameter, guaranteeing sufficient observation range. An entrance pupil diameter of 15mm can be achieved by designing the effective light-gathering aperture of the first lens to 16mm, leaving a 1mm machining allowance to ensure sufficient light intake. An exit pupil distance of 25mm and an exit pupil diameter of 5mm are achieved by optimizing the optical structure of the eyepiece group 5, such as by using a large field of view eyepiece design, allowing the observer to observe comfortably even while wearing a gas mask or goggles, improving the ergonomics of the scope, making it suitable for different observers, and compatible with various equipment.

[0032] In one feasible implementation, in low-light observation mode, the system's spectral transmission range is 480nm~900nm, the magnification is not less than 3 times, the field of view is not less than 15.6°, the entrance pupil diameter is not less than 50mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

[0033] In this technical solution, to achieve a broad spectral transmission range of 480nm~900nm, a broadband antireflective coating can be deposited on the lens surface, for example, using a three- or four-layer film system design, covering a wide band from visible blue light to near-infrared, ensuring that as many photons as possible can reach the sensor in low-light environments such as starlight and moonlight. The 3x magnification is also achieved through the focal length ratio of objective lens group 1 and eyepiece group 5, expanding the field of view to 15.6°. This requires objective lens group 1 to have a larger image-side field of view, achieved by optimizing lens curvature and spacing. The entrance pupil diameter is not less than 50mm, achieved by increasing the aperture of the first lens in objective lens group 1 to 52mm, significantly improving light-gathering capability. The parameters of exit pupil distance and exit pupil diameter are consistent with the visible light mode, satisfied through the unified design of eyepiece group 5, ensuring consistent observation experience in both modes.

[0034] Understandably, the wide spectral range of 480nm~900nm fully utilizes the abundant near-infrared light components in nighttime environments, significantly enhancing the detection capabilities of the photoelectric imaging module 2. The large entrance pupil diameter of no less than 50mm is crucial for the system to obtain clear images in low light conditions. It ensures sufficient photon flux is captured by the image sensor. The larger 15.6° field of view provides a wider field of view when searching for and monitoring targets at night, reducing blind spots and enabling the scope to maintain efficient aiming and observation capabilities during nighttime operations. This complements the visible light mode, truly meeting the needs of all-weather operation.

[0035] In one feasible implementation, objective lens group 1 adopts a six-lens structure, with some glass made of high Abbe number achromatic material, undertaking most of the achromatic function, ensuring good image quality in both visible and low-light modes. Objective lens group 1 includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical path. The entrance pupil of the system is located on the frame of the first lens. The first lens has a light crown glass lens with positive optical power, the second lens has a heavy barium flint glass lens with positive optical power, the third lens has a heavy flint glass lens with negative optical power, the fourth lens has a lanthanum crown glass lens with positive optical power, the fifth lens has a heavy lanthanum flint glass lens with positive optical power, and the sixth lens has a heavy crown glass lens with negative optical power.

[0036] In this technical solution, the first lens can be made of light crown glass with an Abbe number of 70.4 and an optical power of +0.8 diopters, primarily serving to converge light rays. The second lens can be made of heavy barium flint glass with an Abbe number of 48.4 and an optical power of +0.6 diopters, used in combination with the first lens to initially correct spherical aberration. The third lens can be made of heavy flint glass with an Abbe number of 20.9 and an optical power of -0.4 diopters, primarily used to correct positional chromatic aberration. The fourth lens can be made of lanthanum crown glass with an Abbe number of 60.2 and an optical power of +0.5 diopters, further correcting higher-order aberrations. The fifth lens can be made of heavy lanthanum flint glass with an Abbe number of 46.6 and an optical power of +0.7 diopters, used to balance field curvature and astigmatism. The sixth lens can be made of heavy crown glass with an Abbe number of 65.5 and an optical power of -0.3 diopters, serving as the final aberration correction element. In another implementation, the material combination of each lens can be adjusted. For example, the second lens can be made of H-ZBAF3 heavy barium flint glass and the fifth lens can be made of H-ZLAF52A heavy lanthanum flint glass. By fine-tuning the optical power distribution of each lens, a similar achromatic effect can be achieved, but better secondary spectral correction may be obtained.

[0037] Understandably, this six-lens structure achieves apochromatic aberration under both visible and low-light broad-spectrum conditions by rationally allocating positive and negative optical powers and selecting glass materials with different dispersion characteristics. The use of high Abbe number materials, such as light crown glass and lanthanum crown glass, effectively compensates for the dispersion caused by low Abbe number materials, such as heavy flint glass, enabling the system to maintain sharp imaging across the entire operating wavelength range. The meticulous design of the optical powers of each lens not only corrects axial and transverse chromatic aberration but also balances various aberrations such as spherical aberration, coma, astigmatism, and field curvature, ensuring uniform high image quality from the center to the edge of the field of view in both modes. This guarantees that objective group 1 can provide a high-quality initial image regardless of which mode is switched to.

[0038] In one feasible implementation, in visible light viewing mode, the focal length of objective lens group 1 is not less than 60mm, the field of view is not less than 10°, and the entrance pupil diameter is not less than 15mm.

[0039] In this technical solution, the 60mm focal length of objective lens group 1 is achieved through precise calculation and allocation of the curvature radius, thickness, and air gap of the six lenses. As shown in the table, the first lens has a front surface curvature radius of 74.4mm, a rear surface curvature of -457.1mm, and a center thickness of 7.57mm; the second lens has a front surface curvature radius of 44.938mm, a rear surface curvature of 340.4mm, and a center thickness of 7.32mm, and so on. Through optimized combination using optical design software, a final focal length of 60mm is achieved. A field of view of not less than 10° is ensured by controlling the image-side field of view angle of objective lens group 1, ensuring that the principal rays of the peripheral field of view can pass through the subsequent optical system without obstruction. An entrance pupil diameter of not less than 15mm is achieved by designing the effective aperture of the first lens to be 16mm and placing the system entrance pupil on its frame, with the frame itself acting as an aperture stop.

[0040] Understandably, in visible light mode, the 60mm focal length of objective lens group 1, when combined with eyepiece group 5, provides a practical magnification of at least 3x without making objective lens group 1 too long or heavy. A field of view of at least 10° provides the observer with a suitable observation range, allowing for target locking while also taking into account the surrounding environment. An entrance pupil diameter of at least 15mm ensures sufficient light throughput for the system to produce a bright and clear image under bright daylight conditions.

[0041] In one feasible implementation, in low-light observation mode, the focal length of objective lens group 1 is not less than 60mm, the field of view is not less than 15.6°, and the entrance pupil diameter is not less than 50mm.

[0042] In this technical solution, the focal length of objective lens group 1 remains constant at 60mm in low-light mode, ensuring the consistency of the system magnification. The field of view is expanded to no less than 15.6°. Objective lens group 1 can appropriately increase the aperture of the third and fourth lenses and adjust the air gap between them to reduce vignetting. The entrance pupil diameter is no less than 50mm, and the effective light-passing aperture of the first lens is significantly increased to 52mm or even larger. At the same time, the apertures of subsequent lenses are also increased accordingly to match the passage of large light beams.

[0043] Understandably, the design of maintaining the same focal length while significantly increasing the field of view and entrance pupil diameter in low-light mode is a specific optimization for nighttime environments. Maintaining the same focal length ensures that the magnification perceived by the observer remains unchanged when switching from visible light mode to low-light mode, eliminating the need for readjustment. The expanded field of view to 15.6° greatly enhances nighttime search and situational awareness capabilities, enabling rapid target detection and identification in complex environments. The increased entrance pupil diameter to at least 50mm allows objective lens 1 to collect several times more photons than in visible light mode, significantly improving the image signal-to-noise ratio and enabling the optoelectronic imaging module 2 to output usable images in extremely low light conditions. This allows objective lens 1 to "see far," "see wide," and "see clearly" in low-light mode, fully demonstrating the design advantages of a day / night switching sight.

[0044] In one feasible embodiment, the image-spinning lens group 4 adopts a six-element structure, including a set of cemented doublet lenses. The image-spinning lens group 4 includes a seventh lens, a cemented lens, a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially along the optical path. The magnification of the image-spinning lens group 4 is -1x. The seventh lens has a heavy lanthanum flint glass lens with positive optical power. The cemented lens includes an eighth lens and a ninth lens. The eighth lens is a heavy crown glass lens, and the ninth lens is a heavy flint glass lens. The two have similar refractive indices but a large difference in Abbe number. The heavy crown glass lens has positive optical power, and the heavy flint glass lens has negative optical power. The tenth lens has a lanthanum crown glass lens with positive optical power, the eleventh lens has a heavy lanthanum flint glass lens with positive optical power, and the twelfth lens has a heavy crown glass lens with negative optical power.

[0045] In this technical solution, a specific embodiment of the cemented lens can employ a combination of a crown glass lens and a heavy flint glass lens, as shown in lenses 8 and 9 in the table. The crown glass lens has a refractive index of 1.62 and an Abbe number of 63.4, while the heavy flint glass lens has a refractive index of 1.85 and an Abbe number of 23.8. Although their refractive indices are similar, their Abbe numbers differ significantly. After cementation, they can effectively correct the second-order spectrum. The optical power of the crown glass lens is set to +0.9 diopters, and the optical power of the heavy flint glass lens is set to -0.9 diopters. The seventh lens can be H-ZLAF68 heavy lanthanum flint glass, with an optical power of +0.7 diopters, used for preliminary correction of spherical aberration. The tenth lens can be H-LAK6A lanthanum crown glass, with an optical power of +0.5 diopters, used for correcting coma. The eleventh lens can be H-ZLAF52A heavy lanthanum flint glass, with an optical power of +0.6 diopters, used to balance astigmatism. The twelfth lens can be made of H-ZK14 crown glass, with an optical power of -0.6 diopter, to compensate for field curvature. In another embodiment, the cemented lens can be a combination of H-ZK11 crown glass and H-ZF3 heavy flint glass, while the optical power of the seventh lens is adjusted to +0.8 diopter and the optical power of the twelfth lens is adjusted to -0.5 diopter. This fine-tuning optimizes the imaging quality of the entire image-rotating lens group 4.

[0046] Understandably, this solution incorporates a six-element image-rotating lens group 4 design with cemented doublet lenses, achieving -1x magnification while precisely correcting aberrations. The cemented doublet lenses utilize two types of glass with significantly different dispersion characteristics to effectively eliminate axial chromatic aberration and second-order spectral distortion, ensuring wide-band imaging quality from visible light to low light.

[0047] In one feasible implementation, the eyepiece group 5 adopts a large field-of-view two-lens structure. The eyepiece group 5 includes a thirteenth lens and a fourteenth lens arranged sequentially along the optical path. The thirteenth lens has a heavy barium flint glass lens with positive optical power, and the fourteenth lens has a low-dispersion light crown glass lens with positive optical power.

[0048] In this technical solution, the thirteenth lens can be made of heavy barium flint glass, which has a high refractive index of approximately 1.66 and an optical power of +2.5 diopters. This high refractive index material can achieve a large optical power within a relatively short lens thickness, which helps to shorten the overall length of eyepiece group 5. The fourteenth lens can be made of light crown glass, which has an Abbe number as high as 70.4 and extremely low dispersion. Its optical power is set to +1.8 diopters, mainly used to compensate for the chromatic aberration generated by the thirteenth lens and further converge the light.

[0049] Understandably, the thirteenth lens uses high-refractive-index barium flint glass, enabling eyepiece group 5 to achieve a large exit pupil distance and diameter within a limited size, thus ensuring good ergonomic performance. The fourteenth lens uses low-dispersion light crown glass or fluorite glass, effectively eliminating residual chromatic aberration in the eyepiece system itself, ensuring that the final observed image has true colors and sharp edges.

[0050] In one feasible implementation, the eyepiece group 5 has a focal length of 20.03 mm, a relative aperture of 4.001, an exit pupil distance of not less than 25 mm, and an exit pupil diameter of not less than 5 mm.

[0051] In this technical solution, the 20.03mm focal length, combined with the 60mm focal length of objective lens group 1, achieves a system magnification of approximately 3 times, which is consistent with commonly used aiming magnification. The relative aperture of F / 4.001 ensures sufficient field-of-view brightness while effectively controlling aberrations, resulting in a clear image across the entire field of view. The 25mm exit pupil distance and 5mm exit pupil diameter ensure that the observer can quickly and comfortably locate the entire field of view, making it easy to use even when wearing glasses or a gas mask, and providing sufficient tolerance for minor changes in eye position.

[0052] The table below shows the optical system structure parameters of a specific embodiment of the optical system of the present invention, which also reflects the experimental results.

[0053]

[0054] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A day / night switching sight optical system, characterized in that, include: The objective lens group, the image-rotating mirror group, and the eyepiece group are arranged sequentially along the optical path; A reticle and an optoelectronic imaging module are configured to be selectively moved into the optical path between the objective lens group and the rotating mirror group. The optoelectronic imaging module is used to capture light signals and display images. A switching unit is mechanically connected to the reticle and the photoelectric imaging module, and is used to drive the reticle or the photoelectric imaging module to enter the optical path to realize the switching between visible light observation mode and micro light observation mode.

2. The day / night switching sight optical system according to claim 1, characterized in that, The photoelectric imaging module includes: An image sensing element is disposed on the image side of the objective lens group, and is used to receive light signals from the objective lens group and output electrical signals; An image display element is disposed on the object side of the rotating mirror assembly. The image display element is electrically connected to the image sensing element and is used to receive the electrical signal and display the image.

3. The day / night switching sight optical system according to claim 1, characterized in that, In the visible light viewing mode, the system's spectral transmission range is 486nm~656nm, the magnification is not less than 3 times, the field of view is not less than 10°, the entrance pupil diameter is not less than 15mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

4. The day / night switching sight optical system according to claim 1, characterized in that, In the aforementioned low-light observation mode, the system's spectral transmission range is 480nm~900nm, the magnification is not less than 3 times, the field of view is not less than 15.6°, the entrance pupil diameter is not less than 50mm, the exit pupil distance is not less than 25mm, and the exit pupil diameter is greater than 5mm.

5. The day / night switching sight optical system according to claim 1, characterized in that, The objective lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along the optical path, with the entrance pupil of the system located on the frame of the first lens; The first lens has a crown glass lens, and the optical power of the first lens is positive; The second lens has a barium flint glass lens, and the optical power of the second lens is positive; The third lens has a heavy flint glass lens, and the optical power of the third lens is negative. The fourth lens has a lanthanum crown glass lens, and the optical power of the fourth lens is positive. The fifth lens has a lanthanum flint glass lens, and the optical power of the fifth lens is positive. The sixth lens has a crown glass lens and has a negative optical power.

6. The day / night switching sight optical system according to claim 5, characterized in that, In the visible light viewing mode, the focal length of the objective lens group is not less than 60mm, the field of view is not less than 10°, and the entrance pupil diameter is not less than 15mm.

7. The day / night switching sight optical system according to claim 5, characterized in that, In the low-light observation mode, the focal length of the objective lens group is not less than 60mm, the field of view is not less than 15.6°, and the entrance pupil diameter is not less than 50mm.

8. The day / night switching sight optical system according to claim 1, characterized in that, The image-rotating mirror group includes a seventh lens, a cemented lens, a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially along the optical path, and the magnification of the image-rotating mirror group is -1. The seventh lens has a lanthanum flint glass lens, and the optical power of the seventh lens is positive. The cemented lens includes a crown glass lens and a heavy flint glass lens, wherein the optical power of the crown glass lens is positive and the optical power of the heavy flint glass lens is negative. The tenth lens has a lanthanum crown glass lens, and the optical power of the tenth lens is positive. The eleventh lens has a lanthanum flint glass lens, and the optical power of the eleventh lens is positive. The twelfth lens has a crown glass lens and a negative optical power.

9. The day / night switching sight optical system according to claim 1, characterized in that, The eyepiece group includes a thirteenth lens and a fourteenth lens arranged sequentially along the optical path; The thirteenth lens has a barium flint glass lens, and the optical power of the thirteenth lens is positive. The fourteenth lens has a low-dispersion light crown glass lens, and the optical power of the fourteenth lens is positive.

10. The day / night switching sight optical system according to claim 9, characterized in that, The focal length of the eyepiece group is not less than 20mm, the relative aperture is not less than 4, the exit pupil distance is not less than 25mm, and the exit pupil diameter is not less than 5mm.

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