Eyepiece and eyepiece optical system

Abstract

The embodiment of the invention provides an eyepiece and an eyepiece optical system. The eyepiece comprises a first lens group and a second lens group which are arranged along the same optical axis, the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side; the first lens group comprises a first lens, a second lens and a third lens which are sequentially arranged along the optical axis; the second lens group comprises a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the optical axis; the eyepiece satisfies the following condition: 0.049 < n1 / f1 + n2 / f2 + n3 / f3 + n4 / f4 + n5 / f5 + n6 / f6 < 0.08; wherein n1 to n6 are the refractive indexes of the first lens to the sixth lens respectively, and f1 to f6 are the focal lengths of the first lens to the sixth lens respectively.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical technology, and more specifically, to an eyepiece and an eyepiece optical system. Background Art

[0002] Sighting lenses are widely used in scientific research, outdoor sports and other fields. In recent years, with the development of technology, the performance requirements for sighting lenses have become increasingly higher. When traditional sighting lenses meet these requirements, they often have problems such as complex structure, high production cost, and poor imaging effect. Therefore, a new type of sighting lens is needed to solve these problems. Summary of the invention

[0003] The purpose of this application is to provide a new technical solution for an eyepiece and an eyepiece optical system.

[0004] In a first aspect, the present application provides an eyepiece. The eyepiece includes a first lens group and a second lens group arranged along the same optical axis, the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side;

[0005] The first lens group includes a first lens, a second lens and a third lens arranged in sequence along the optical axis;

[0006] The second lens group includes a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis;

[0007] The eyepiece satisfies: 0.049<n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6<0.08; wherein n1~n6 are the refractive indices of the first lens to the sixth lens respectively, and f1~f6 are the focal lengths of the first lens to the sixth lens respectively.

[0008] Optionally, the eyepiece satisfies: 0.65<(EP×ED) / (f×h)<2.3; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

[0009] Optionally, the fourth lens, the fifth lens and the sixth lens are glued together in sequence to form a glued lens group.

[0010] Optionally, the fourth lens and the sixth lens both have positive optical power, and the fifth lens has negative optical power.

[0011] Optionally, the first lens, the second lens and the third lens all have positive optical power.

[0012] Optionally, the eyepiece satisfies: 0.042<(1 / F1)+(1 / F2)<0.08; wherein F1 is the focal length of the first lens group, and F2 is the focal length of the second lens group.

[0013] Optionally, the eyepiece satisfies: 1.19<F1 / f<1.3; wherein F1 is the focal length of the first lens group, and f is the total focal length of the eyepiece.

[0014] Optionally, the fourth lens is a biconvex lens, the fifth lens is a biconcave lens, and the sixth lens is a concave-convex lens.

[0015] Optionally, the first lens is a biconvex lens, the second lens is a plano-convex lens, and the third lens is a convex-concave lens.

[0016] Optionally, the exit pupil distance EP of the eyepiece is 35 mm to 45 mm, the exit pupil diameter ED of the eyepiece is 4 mm to 8 mm, and the F number of the eyepiece is 2.125 to 4.25.

[0017] Optionally, the image height of the eyepiece is 9.2 mm to 12.6 mm.

[0018] In a second aspect, the present application provides an eyepiece optical system. The eyepiece optical system comprises:

[0019] An eyepiece as described in the first aspect.

[0020] The beneficial effects of this application are:

[0021] The eyepiece provided in the embodiment of the present application is a sighting lens with a long exit pupil distance and a large aperture, which can solve the problems existing in the prior art. The eyepiece provided in the embodiment of the present application achieves excellent imaging effects at a long exit pupil distance through a specially designed combination of multiple lenses. At the same time, it has the characteristics of a large aperture and can provide clear imaging in low-light environments. The eyepiece provided in the embodiment of the present application provides a larger field of view and a comfortable visual observation experience based on the design of a long exit pupil distance. Therefore, the eyepiece of the present application has the effects of optimized imaging effects, a large aperture, a comfortable visual observation experience, and a wide range of application prospects, and can meet the observation needs in many fields such as scientific research and outdoor sports.

[0022] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0024] Figure 1 A schematic diagram of the structure of the eyepiece provided in an embodiment of the present application;

[0025] Figure 2 A dot array diagram of the eyepiece provided in an embodiment of the present application;

[0026] Figure 3 The MTF diagram of the eyepiece provided in the embodiment of the present application;

[0027] Figure 4 Distortion and field curvature diagram of the eyepiece provided in the embodiment of the present application;

[0028] Figure 5 This is a diagram of the vertical axis chromatic aberration of the eyepiece provided in an embodiment of the present application.

[0029] Description of reference numerals:

[0030] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0033] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0034] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0035] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] The eyepiece and the eyepiece optical system provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0037] According to one embodiment of the present application, an eyepiece is provided, see Figure 1The eyepiece comprises a first lens group and a second lens group arranged along the same optical axis, the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side; the first lens group comprises a first lens 1, a second lens 2 and a third lens 3 arranged in sequence along the optical axis; the second lens group comprises a fourth lens 4, a fifth lens 5 and a sixth lens 6 arranged in sequence along the optical axis; the eyepiece satisfies: 0.049<n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6<0.08; wherein n1~n6 are the refractive indices of the first lens 1 to the sixth lens 6, respectively, and f1~f6 are the focal lengths of the first lens 1 to the sixth lens 6, respectively.

[0038] The eyepiece proposed in the embodiment of the present application is a sighting lens with a long exit pupil distance and a large aperture, and has a wide range of applications. The following is a description of its application range.

[0039] The eyepiece provided in the embodiment of the present application has the characteristics of long pupil distance and large aperture, and the eyepiece can provide clear and stable imaging effect. Therefore, the eyepiece provided in the present application is very suitable for use in optical devices such as telescopes and sights, and can meet the observation needs of users in complex environments.

[0040] In the field of scientific research, the imaging quality and stability of optical observation equipment are extremely high. The eyepiece of the embodiment of the present application can be used in optical equipment / instruments such as scientific research telescopes and microscopes due to its excellent optical performance, which can help researchers obtain more accurate experimental data.

[0041] For outdoor sports enthusiasts, telescopes or sighting equipment with excellent optical performance are indispensable. The eyepiece of the embodiment of the present application has a wide field of view and a comfortable observation experience, and is very suitable for outdoor scenes.

[0042] To sum up, the eyepiece provided in the embodiment of the present application has broad application prospects due to its long exit pupil distance, large aperture and excellent imaging quality, and can meet the usage needs of scientific research, outdoor sports and many other fields.

[0043] The eyepiece provided in the embodiment of the present application, from the perspective of its optical architecture, see Figure 1 The eyepiece includes two lens groups: a first lens group and a second lens group, which are arranged along the same optical axis. The first lens group is located on the exit pupil side, that is, the side close to the observer's eyes; and the second lens group is located on the focal plane side, that is, the side close to the observed object or the imaging surface. This layout ensures that light can pass through the eyepiece along a predetermined path, thereby achieving clear imaging.

[0044] Please continue to see Figure 1The first lens group is mainly composed of a first lens 1, a second lens 2 and a third lens 3, which work together to initially converge and adjust the light entering the eyepiece. The second lens group is mainly composed of a fourth lens 4, a fifth lens 5 and a sixth lens 6, which further focus and optimize the light to ensure the quality of the final image.

[0045] In the eyepiece optical architecture provided in the embodiment of the present application, it should be clearly pointed out that the specific number of lenses in the first lens group and the second lens group is not absolutely fixed, but can be flexibly adjusted according to the actual application scenario requirements and design specifications. In other words, the number of lenses in the two lens groups can be appropriately increased or decreased according to the final imaging effect requirements.

[0046] The first lens group is a lens group located on the exit pupil side, and its main function is to adjust and control the incident angle and path of light to ensure that the light can enter the eyepiece. Therefore, according to specific design requirements, the number of lenses in the first lens group can be appropriately increased or decreased to achieve the best optical effect.

[0047] The second lens group is a lens group located on the focal plane side, and its main function is to further focus and optimize the light to achieve high-quality imaging. In the second lens group, the number of lenses can also be adjusted according to specific imaging requirements. By increasing or decreasing the number of lenses, the performance parameters of the eyepiece such as imaging quality, aperture size, and field of view can be further optimized.

[0048] The lens quantity adjustment mechanism enables the eyepiece of the present application to better adapt to different application scenarios and usage requirements. Whether it is a telescope that requires high definition or an outdoor sports sighting device that requires a wide field of view, the specific performance requirements can be met by adjusting the number of lenses.

[0049] A key feature of the embodiment of the present application is that the eyepiece satisfies a specific relationship between the sum of the refractive index and the focal length, that is, 0.049 < n1 / f1 + n2 / f2 + n3 / f3 + n4 / f4 + n5 / f5 + n6 / f6 < 0.08. This specific constraint relationship ensures that the optical properties of the various lenses can match and coordinate with each other, thereby achieving an overall optimized imaging effect. Specifically, the setting of this parameter in the present application can not only ensure the imaging quality, but also take into account the large aperture effect, and can also ensure the stability of the optical performance of the eyepiece, and control the manufacturing cost, etc.

[0050] When n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6 is less than 0.049, it means that this parameter may be too small, which means that the refractive index of some lenses is not well matched to their focal length, which may result in the light not being fully converged and adjusted when passing through these lenses, thus affecting the final image quality.

[0051] Since the parameter n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6 is related to the aperture performance, if the parameter is too small, the large aperture effect may not be fully utilized, which will affect the imaging effect of the eyepiece in low light environments. In addition, this overly small parameter design may also require a more complex lens design or material selection, thereby increasing the difficulty and cost of design and production.

[0052] When n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6 is greater than 0.08, it means that this parameter may be too large. This excessively large parameter may also bring adverse effects. For example, it may cause an increase in various aberrations (such as spherical aberration, chromatic aberration, etc.). These aberrations will seriously affect the clarity and accuracy of the imaging.

[0053] In application, controlling the parameter n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6 in the range of 0.049 to 0.08 can ensure that the overall performance of the eyepiece of the present application reaches the optimal state.

[0054] The eyepiece provided in the embodiment of the present application is shown in FIG. Figure 1 By rationally combining lenses and adjusting the refractive index and focal length of each lens, the entire eyepiece can still maintain excellent imaging effects at a long exit pupil distance. This is due to the mutual matching and coordination of the optical properties of each lens. The eyepiece design provided in the embodiment of the present application has the characteristics of a large aperture and can provide clear imaging effects in low light environments.

[0055] It should be noted that the design of long exit pupil distance enables the eyepiece to provide a larger field of view and a more comfortable visual observation experience during observation, which is especially suitable for scenarios of long-term use.

[0056] The eyepiece provided in the embodiment of the present application is a sighting lens with a long exit pupil distance and a large aperture, which can solve the problems existing in the prior art. The eyepiece provided in the embodiment of the present application achieves excellent imaging effects at a long exit pupil distance through a specially designed combination of multiple lenses. At the same time, it has the characteristics of a large aperture and can provide clear imaging in low-light environments. The eyepiece provided in the embodiment of the present application provides a larger field of view and a comfortable visual observation experience based on the design of a long exit pupil distance. Therefore, the eyepiece of the present application has the effects of optimized imaging effects, a large aperture, a comfortable visual observation experience, and a wide range of application prospects, and can meet the observation needs in many fields such as scientific research and outdoor sports.

[0057] In some examples of the present application, the eyepiece satisfies: 0.65<(EP×ED) / (f×h)<2.3; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

[0058] In this example of the present application, a key mathematical inequality regarding the performance of the eyepiece is given: 0.65<(EP×ED) / (f×h)<2.3, where the meanings of the various symbols are as follows:

[0059] EP: It refers to the exit pupil distance of the eyepiece provided in this application, which refers to the distance from the rearmost surface of the eyepiece to the exit pupil (i.e., the position where the observer's eyes should be placed).

[0060] ED: It refers to the exit pupil diameter of the eyepiece provided in this application. It is the diameter of the exit pupil, which will affect the brightness and breadth of the observer's field of view.

[0061] f: It refers to the total focal length of the eyepiece provided in this application, which is the distance from the optical center of the eyepiece to the imaging surface.

[0062] h: It refers to the image height of the eyepiece provided in this application, that is, the height of the imaging surface.

[0063] In this application, by adjusting the exit pupil diameter (ED), the observer's field of view can be expanded while ensuring sufficient field of view brightness. This is particularly important for sighting lenses, for example, because it needs to ensure a clear and bright field of view under a variety of lighting conditions.

[0064] The inequality provided in this example of the present application also takes into account the total focal length (f) and image height (h) of the eyepiece, which directly affect the clarity and field of view of the image. Through calculation and adjustment, stable imaging quality can be maintained under different focal lengths and image heights, thereby enhancing the applicability and performance of the eyepiece.

[0065] The inequality provided in this example of the present application provides a comprehensive design parameter to help technicians balance various performance indicators when designing eyepieces, such as field of view brightness, field of view range, imaging quality, exit pupil distance, etc. By optimizing these parameters, a sighting lens with excellent performance can be created.

[0066] When (EP×ED) / (f×h) is less than 0.65, it means that the exit pupil diameter (ED) is small relative to other parameters, which may lead to insufficient field of view brightness. In applications such as sighting lenses, a bright field of view is essential for accurate observation and aiming. Insufficient brightness may make it difficult for observers to see the target clearly in low light conditions.

[0067] A smaller exit pupil diameter may also limit the observer's field of view, resulting in only a limited area near the target being visible during observation, which may affect the comprehensiveness and accuracy of observation.

[0068] In addition, for observation lenses that need to be worn for a long time, a smaller exit pupil distance (EP) may cause eye discomfort or fatigue to the wearer, especially for observers wearing glasses, who may need more frequent adjustments to maintain a clear field of vision.

[0069] When (EP×ED) / (f×h) is greater than 2.3, it means that the exit pupil diameter is too large relative to other parameters, which may cause imaging distortions such as barrel distortion or pincushion distortion. These distortions affect the observer's accurate judgment of the shape and size of the target.

[0070] Excessively large exit pupil diameters may also increase the likelihood of flare and glare, especially near strong light sources. Flare and glare can interfere with the observer's line of sight and reduce the accuracy of observation.

[0071] In addition, under certain focal length and image height conditions, a too large ratio may lead to unstable imaging performance, such as focus drift or image blur, which will affect the applicability and performance of the eyepiece.

[0072] When the ratio of (EP×ED) / (f×h) falls between 0.65 and 2.3, the exit pupil diameter (ED) is relatively moderate, which can ensure that the observer obtains sufficient field of view brightness under different lighting conditions. The moderate exit pupil diameter also helps to expand the observer's field of view, allowing the observer to have a more comprehensive understanding of the surrounding environment, thereby improving the accuracy and safety of observation. Through reasonable design, the eyepiece of the present application can provide the observer with a comfortable wearing experience while maintaining a clear field of view. This helps to reduce eye fatigue and discomfort and improve the observer's satisfaction with use.

[0073] The ratio range provided in this example of the present application takes into account the total focal length and image height of the eyepiece, which directly affect the clarity and field of view of the image. Through precise calculation and adjustment, stable imaging quality can be maintained under different focal lengths and image heights, thereby enhancing the applicability and performance of the eyepiece. Since the ratio range can balance various performance indicators, the eyepiece of the present application can be applied to a variety of application scenarios and observation needs. This increases the market competitiveness and application range of the eyepiece.

[0074] In some examples of this application, see Figure 1 The fourth lens 4, the fifth lens 5 and the sixth lens 6 are glued in sequence to form a glued lens group.

[0075] In this example of the present application, the cemented design of the fourth lens 4, the fifth lens 5 and the sixth lens 6 helps to correct chromatic aberration in different wavelength ranges from visible light to infrared light, and improves the imaging quality. The cemented lens group can also effectively control various aberrations, such as spherical aberration, coma and astigmatism. These aberrations are key factors affecting the clarity and sharpness of imaging.

[0076] The cemented lens design has higher mechanical strength than a single lens. This is because the cementing material tightly binds the multiple lenses together to form a more solid overall structure.

[0077] In actual applications, the sighting lens may be affected by external factors such as vibration and impact. The design of the cemented lens group helps to improve the impact resistance and stability of the lens.

[0078] Lenses made of different materials have different thermal expansion coefficients when the temperature changes. By properly selecting and matching these materials, the cemented lens group can maintain relatively stable optical performance when the temperature changes. This is especially important for sighting lenses that need to work in high or low temperature environments.

[0079] In addition, from the perspective of manufacturing cost and efficiency, the glued lens group is processed and assembled as a whole during the manufacturing process, which helps to simplify the assembly process and improve production efficiency. In contrast, if a single lens design is adopted, the position and angle of each lens need to be assembled and adjusted one by one, which will undoubtedly increase the manufacturing difficulty and cost.

[0080] In some examples of the present application, the fourth lens 4 and the sixth lens 6 both have positive refractive power, and the fifth lens 5 has negative refractive power.

[0081] In this example of the present application, the fourth lens 4 and the sixth lens 6 both have positive power, while the fifth lens 5 has negative power. This design produces a significant technical effect in the eyepiece of the present application, especially when these three lenses are part of the second lens group (focal plane side), the effect is more prominent. The following is a detailed analysis of this design.

[0082] Positive refractive power lenses such as the fourth lens 4 and the sixth lens 6 help converge light, while negative lenses such as the fifth lens 5 located between the two positive lenses play a role in diverging light. By combining these three lenses in positive, negative and positive modes, the focal length of the second lens group can be adjusted, and then the focal length of the entire eyepiece can be adjusted.

[0083] This design in this example of the present application helps to correct various aberrations, such as spherical aberration, coma and field curvature, thereby improving the imaging quality. In particular, the negative optical power fifth lens 5 can effectively balance the aberration introduced by the positive optical power lens, so that the aberration of the entire second lens group is better controlled.

[0084] For the eyepiece of the present application, the combined design of positive and negative optical powers in the second lens group also helps to achieve the optical effects of a large aperture and a long exit pupil distance of the entire eyepiece. Among them, the large aperture can increase the amount of light passing through the eyepiece, so that a bright image can be obtained even in a low-light environment. And the long exit pupil distance helps to reduce the distance between the eyepiece and the observer's eyes, improving the viewing comfort.

[0085] In this example of the present application, the positive focal lengths of the fourth lens 4 and the sixth lens 6 can converge more light, while the negative focal length of the fifth lens 5 plays a role in adjusting the focal length and correcting aberrations, thereby achieving the design goals of large aperture and long exit pupil distance. In addition, as part of the second lens group, the fourth lens 4 to the sixth lens 6 have a compact structural design that helps to miniaturize the entire eyepiece.

[0086] In some examples of the present application, the first lens 1 , the second lens 2 , and the third lens 3 all have positive refractive power.

[0087] In the eyepiece of the embodiment of the present application, the first lens group includes three lenses, namely a first lens 1, a second lens 2 and a third lens 3 which are sequentially arranged along the same optical axis.

[0088] In this example of the present application, the three lenses in the first lens group are all positive lenses, that is, the first lens 1 to the third lens 3 are all positive lenses, and the three of them work together to effectively converge the light emitted from the observed object. This design helps to increase the light throughput of the eyepiece and ensure that a clear image can be obtained even in a low-light environment. At the same time, the combination of positive-power lenses also helps to correct various aberrations, which is crucial to improving image quality.

[0089] There is a synergistic effect between the first lens group and the second lens group in this example of the present application. When the positive power lens in the first lens group is matched with the three lenses in the second lens group (especially the fourth lens 4 has positive power, the fifth lens 5 has negative power, and the sixth lens 6 has positive power), more complex and precise optical performance control can be achieved.

[0090] The negative focal length design of the fifth lens 5 helps to balance the positive focal length introduced by the first lens group, the fourth lens 4 and the sixth lens 6, thereby further correcting aberrations and improving imaging quality. At the same time, this design also helps to achieve the goals of long exit pupil distance and large aperture.

[0091] The design of long exit pupil distance helps to reduce the distance between the eyepiece and the observer's eyes, improving the viewing comfort. The positive power lens combination in the first lens group provides a design basis for the design of long exit pupil distance by converging light. When combined with the lens in the second lens group, the optical path of the entire eyepiece is optimized, further ensuring the realization of long exit pupil distance.

[0092] A large aperture can increase the amount of light passing through the lens, so that a bright image can be obtained even in a low-light environment. The positive power lens combination in the first lens group provides a basis for achieving a large aperture by converging more light. At the same time, the lens design in the second lens group also takes into account the need for a large aperture, and through precise power distribution and aperture design, the goal of a large aperture is achieved together.

[0093] In some examples of the present application, the eyepiece satisfies: 0.042<(1 / F1)+(1 / F2)<0.08; wherein F1 is the focal length of the first lens group, and F2 is the focal length of the second lens group.

[0094] The eyepiece proposed in this example of the present application satisfies the condition that the focal length ratio of the first lens group and the second lens group is constrained and reasonably designed. By controlling the reciprocal of the sum of the focal lengths of the two lens groups (i.e. (1 / F1)+(1 / F2)) in the range of 0.042 to 0.08, more precise optical performance control can be achieved. This reasonable focal length ratio helps to better correct various aberrations.

[0095] Specifically, when the focal length ratio of the first lens group and the second lens group meets the above conditions, the optical power and aberration correction capability of each lens can be more effectively balanced, thereby obtaining a clearer image.

[0096] In addition, this focal length ratio also helps to improve the resolution of the lens. Resolution is one of the important indicators to measure the imaging quality of the lens. By precisely controlling the focal length ratio, the eyepiece can better retain the detailed information of the object during the imaging process, thereby improving the resolution.

[0097] The design of long pupil distance helps to improve observation comfort. In this example of the present application, by optimizing the focal length ratio, it can be ensured that the first lens group and the second lens group maintain a certain balance when converging light, thereby achieving the design goal of long pupil distance.

[0098] The design of a large aperture can increase the amount of light transmitted by the eyepiece of the present application, so that a bright image can be obtained even in a low-light environment. The optimization of the focal length ratio provided in this example of the present application helps to ensure that the eyepiece of the present application does not sacrifice too much imaging quality while maintaining a large aperture. This allows the eyepiece to maintain a good imaging effect even in a low-light environment.

[0099] The optimization of the focal length ratio also helps to improve the stability of the entire eyepiece. When the focal length ratio of the first lens group and the second lens group is kept within a reasonable range, it can be ensured that the eyepiece can maintain stable optical performance under various environmental conditions.

[0100] When (1 / F1)+(1 / F2) is less than 0.042, it means that the focal lengths of the first lens group and the second lens group are relatively long, or the difference between their focal lengths is relatively large. This may lead to a weakening of the light convergence ability. This is because a longer focal length means that the light convergence ability is weakened when passing through the eyepiece, which will lead to a reduction in the amount of light passing through the eyepiece, thereby affecting the brightness and clarity of the image.

[0101] The increase in focal length is accompanied by a reduction in the field of view, which may limit the observation range of the eyepiece and make it difficult for users to capture a wider scene.

[0102] In addition, a longer focal length may require the eyepiece to have a larger physical size, which is not conducive to achieving lightweight and miniaturization of the lens.

[0103] When (1 / F1)+(1 / F2) is greater than 0.08, it means that the focal lengths of the first lens group and the second lens group are relatively short, or the difference between their focal lengths is relatively small. A shorter focal length may cause light to converge excessively when passing through the eyepiece, resulting in an overly strong convergence effect. This may cause image distortion or other optical problems. A shortened focal length may also increase the generation of various aberrations. These aberrations may affect the image quality.

[0104] In addition, in order to achieve a shorter focal length and maintain high-quality imaging, higher-precision manufacturing processes and materials may be required, which will lead to an increase in the manufacturing cost of the eyepiece.

[0105] In summary, the condition of 0.042<(1 / F1)+(1 / F2)<0.08 plays a vital role in the design of the eyepiece of the present application. It ensures that the eyepiece can effectively correct aberrations and maintain stability while maintaining sufficient light throughput and field of view. When (1 / F1)+(1 / F2) exceeds the range constrained in this example of the present application, it will lead to problems such as weakened light convergence ability, limited field of view, increased difficulty in aberration correction, and reduced structural compactness (less than 0.042), or it will lead to problems such as excessive light convergence, increased aberrations, reduced eyepiece stability, and increased manufacturing costs (greater than 0.08).

[0106] In some examples of the present application, the eyepiece satisfies: 1.19<F1 / f<1.3; wherein F1 is the focal length of the first lens group, and f is the total focal length of the eyepiece.

[0107] In this example of the present application, the ratio range of 1.19<F1 / f<1.3 plays an important role in the design of the eyepiece, which ensures that the eyepiece can achieve good aberration correction and optical stability while maintaining a sufficient field of view, light convergence ability and imaging quality. In this example of the present application, the best optical performance is obtained by controlling the ratio of the focal length of the first lens group to the total focal length of the entire eyepiece.

[0108] When the ratio of F1 / f is less than 1.19, it means that the focal length F1 of the first lens group is shorter than the total focal length f of the entire eyepiece. A shorter focal length of the first lens group may lead to increased distortion at the edge of the field of view, affecting the accuracy and realism of the imaging. A shorter focal length of the first lens group may make the light convergence ability when passing through the eyepiece insufficient, resulting in a decrease in the brightness and contrast of the imaging. A shorter focal length of the first lens group may also increase aberrations, thereby affecting the imaging quality.

[0109] When the ratio of F1 / f is greater than 1.3, it means that the focal length F1 of the first lens group is longer than the total focal length f of the entire eyepiece. The longer focal length of the first lens group may reduce the field of view of the entire eyepiece, which is not conducive to the user capturing a wider scene. The longer focal length of the first lens group is also not conducive to achieving lightweight and miniaturization of the eyepiece.

[0110] In some examples of this application, see Figure 1 The fourth lens 4 is a biconvex lens, the fifth lens 5 is a biconcave lens, and the sixth lens 6 is a concave-convex lens.

[0111] In the eyepiece of the present application, the second lens group includes a fourth lens 4, and the fourth lens 4 is adjacent to and spaced from the third lens 3 in the first lens group. The fourth lens 4 is a biconvex lens, and the design of the biconvex lens means that the lens has a convex shape on both surfaces, which can be used to enhance the positive focal length of the lens. In the eyepiece of the present application, the positive focal length helps to focus light onto the focal plane, thereby improving the clarity of the image.

[0112] By using a biconvex lens as the fourth lens, the aberration introduced by the first lens group can be further corrected. In addition, it also helps to improve the overall light throughput of the eyepiece, allowing the eyepiece to better capture images in low-light environments.

[0113] In the eyepiece of the present application, the second lens group includes a fifth lens 5, and the fifth lens 5 is a biconcave lens. The biconcave lens has a concave shape on both surfaces, which can be used to provide negative optical power. In the entire eyepiece design, the lens with negative optical power helps to disperse light, thereby balancing the focusing effect introduced by the positive optical power lens.

[0114] The fifth lens 5, as a biconcave lens, can further correct aberrations such as field curvature and distortion. By introducing an appropriate amount of negative optical power, it can also help adjust the overall focal length of the entire eyepiece to ensure that the image can be accurately focused on the focal plane.

[0115] The eyepiece of the present application, the second lens group also includes a sixth lens 6, and the sixth lens 6 is a concave-convex lens. One surface of the concave-convex lens is convex and the other surface is concave, which makes it possible to provide a combination effect of positive focal length and negative focal length to a certain extent. As a concave-convex lens, the sixth lens can further fine-tune the imaging performance of the eyepiece. In addition, it also helps to improve the contrast and resolution of the lens, making the image clearer and sharper.

[0116] In this example of the present application, the design of each lens of the second lens group achieves excellent imaging performance of a long exit pupil distance and large aperture aiming lens through precise optical focal length distribution and surface shape combination.

[0117] In some examples of this application, see Figure 1 The first lens 1 is a biconvex lens, the second lens 2 is a plano-convex lens, and the third lens 3 is a convex-concave lens.

[0118] The eyepiece provided in the embodiment of the present application is shown in FIG. Figure 1 , the first lens group includes a first lens 1 to a third lens 3.

[0119] The first lens 1 is a biconvex lens. The design of the biconvex lens means that it has a convex shape on both surfaces, thereby enhancing the positive focal length of the lens. In the eyepiece provided in the present application, the positive focal length is a key factor in focusing light to the focal plane. Using the first lens 1 as a biconvex lens can efficiently collect and focus incident light, thereby improving the luminous flux and imaging quality of the eyepiece.

[0120] The second lens 2 is a plano-convex lens, one surface of which is flat and the other surface is convex. This design can provide positive optical power to a certain extent while reducing weight and cost. As a plano-convex lens, the second lens 2 can further correct the aberration introduced by the first lens 1 while maintaining the overall optical power balance of the eyepiece. Its flat surface also helps to simplify the processing and assembly process.

[0121] The third lens 3 is a convexoconcave lens, one surface of which is convex and the other surface is concave, which enables it to provide a combined effect of positive and negative optical power to a certain extent. This design helps to achieve more complex aberration correction in the eyepiece. As a convexoconcave lens, the third lens 3 can fine-tune the imaging performance of the eyepiece and correct high-order aberrations such as chromatic aberration and field curvature by adjusting the curvature and thickness of its surface. It also helps to balance the optical power of the first lens group to ensure that the image can be accurately focused on the focal plane.

[0122] In the eyepiece of the present application, the second lens group includes the fourth lens 4 to the sixth lens 6. As previously analyzed, the fourth lens 4 is a biconvex lens design that enhances the positive focal length, further corrects aberrations and increases the light flux. The fifth lens 5 is a biconcave lens and provides negative focal length, which helps to disperse light and correct field curvature and distortion. The sixth lens 6 is a concave-convex lens that can fine-tune the imaging performance of the eyepiece, correct high-order aberrations, and improve contrast and resolution.

[0123] By combining the first lens 1 to the third lens 3 (first lens group) and the fourth lens 4 to the sixth lens 6 (second lens group), an efficient eyepiece can be formed. By precisely designing the focal length and surface shape of each lens, as well as the matching between them, various aberrations can be corrected and the luminous flux, contrast and resolution of the eyepiece can be improved. In addition, this design also helps to achieve the effects of long exit pupil distance and large aperture. The long exit pupil distance allows the eyepiece to maintain clear imaging over a wider viewing angle, while the large aperture allows the eyepiece to better capture images in low light environments. These characteristics enable the eyepiece to have excellent imaging performance in a variety of application scenarios.

[0124] Optionally, in the present application, the first lens 1 to the sixth lens 6 are all glass spherical lenses. Spherical lenses can provide stable imaging performance. In addition, the manufacturing process of spherical lenses is relatively simple, with high production efficiency, and is suitable for large-scale production. Glass materials have excellent light transmittance and refractive index stability, which enables lenses made of glass to provide clear, high-quality images.

[0125] Of course, the first lens 1 to the sixth lens 6 may also be partially or entirely made of plastic material. The first lens 1 to the sixth lens 6 may all be aspherical lenses.

[0126] In some examples of the present application, the exit pupil distance EP of the eyepiece is 35 mm to 45 mm, the exit pupil diameter ED of the eyepiece is 4 mm to 8 mm, and the F number of the eyepiece is 2.125 to 4.25.

[0127] In this example of the present application, the pupil distance EP is 35 mm to 45 mm. This design can enhance wearing comfort. The pupil distance refers to the distance from the observer's eye to the eyepiece exit pupil surface. The pupil distance within the above range can accommodate the eye distance of most people, including observers wearing glasses, thereby providing a comfortable viewing experience.

[0128] The eyepiece provided in the present application has a longer pupil distance. The longer pupil distance makes the distance between the observer's eyes and the eyepiece more comfortable when using the eyepiece, reducing eye fatigue during long-term observation. This is particularly important for application scenarios that require long-term use of the sighting lens (such as shooting, telescope observation, etc.). As the pupil distance increases, the field of view observed by the observer through the eyepiece will also expand accordingly. This is an important advantage for sighting tasks that require a wide field of view.

[0129] In this example of the present application, the exit pupil diameter ED is 4 mm to 8 mm. This design ensures sufficient visual field brightness. The size of the exit pupil diameter directly affects the amount of light entering the observer's eyes. The exit pupil diameter within this range can ensure that the observer can obtain a sufficiently bright visual field under different lighting conditions, thereby improving the clarity of observation.

[0130] The eyepiece provided by the present application has a larger exit pupil diameter. A larger exit pupil diameter helps to expand the observer's field of view, enabling the observer to have a more comprehensive understanding of the surrounding environment and improve the accuracy and safety of observation.

[0131] In this example of the present application, the eyepiece F number is 2.125 to 4.25. This design can balance the image quality and light throughput. The F number is the ratio of the focal length of the eyepiece to the exit pupil diameter, which reflects the light throughput and image quality of the eyepiece. The F number within this range can balance the light throughput and image clarity, so that the eyepiece can provide high-quality imaging under various lighting conditions.

[0132] By adjusting the F number, you can adapt to different observation needs and scenes. For example, a smaller F number (i.e., a larger light flux) is suitable for bright environments, while a larger F number (i.e., a smaller light flux but higher image clarity) is suitable for dim environments.

[0133] The eyepiece parameter range in this example of the present application, namely, the exit pupil distance EP is 35mm to 45mm, the exit pupil diameter ED is 4mm to 8mm, and the eyepiece F number is 2.125 to 4.25, together achieves the following technical effects:

[0134] (1) Improving wearing comfort and adaptability: Through reasonable design of exit pupil distance and exit pupil diameter, the eyepiece provided in this application can be suitable for a wider range of people and usage scenarios.

[0135] (2) Ensure the brightness and clarity of the field of view: It can provide a sufficiently bright field of view and clear imaging effects under different lighting conditions.

[0136] (3) Optimizing image quality and light throughput: By balancing the F number, the best match between image quality and light throughput is achieved to meet diverse observation needs.

[0137] The above-mentioned technical effects jointly improve the overall performance and user experience of the eyepiece, making the eyepiece have broad application prospects in the field of observation and aiming.

[0138] In some examples of the present application, the image height of the eyepiece is 9.2 mm to 12.6 mm.

[0139] The image height determines the size of the image presented by the eyepiece. The image height within this range in this example of the present application can ensure that the observer has a sufficiently large field of view, so as to have a more comprehensive understanding of the surrounding environment and improve the observation efficiency. A larger image height can make the image clearer and more delicate, and the observer can more easily identify the target details, improving the observation experience.

[0140] When designing an eyepiece, a trade-off needs to be made between image quality and image height. Image height within this range can ensure that the eyepiece provides a sufficiently large field of view while maintaining good image quality.

[0141] As an important part of the sighting lens, the performance of the eyepiece directly affects the performance of the entire lens. Reasonable image height design can improve the overall performance of the system, including key indicators such as resolution and contrast.

[0142] The eyepiece of the present application is further described below through Example 1 and Example 2.

[0143] Example 1

[0144] The eyepiece provided in this embodiment 1 is shown in FIG. Figure 1 , comprising a first lens group and a second lens group arranged along the same optical axis, wherein the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side;

[0145] The first lens group includes a first lens 1, a second lens 2 and a third lens 3, and the first lens 1, the second lens 2 and the third lens 3 all have positive refractive power;

[0146] The second lens group includes a fourth lens 4, a fifth lens 5 and a sixth lens 6, wherein the fifth lens 5 has a negative optical power, and the fourth lens 4 and the sixth lens 6 both have positive optical power; wherein the fourth lens 4 and the third lens 3 are disposed adjacent to each other;

[0147] The first lens 1 is a biconvex lens, the second lens 2 is a plano-convex lens, the third lens 3 is a convex-concave lens, the fourth lens 4 is a biconvex lens, the fifth lens 5 is a biconcave lens, the sixth lens 6 is a concave-convex lens, and the first lens 1 to the sixth lens 6 are glass spherical mirrors;

[0148] The focal length F1 of the first lens group is 20.33 mm, the focal length F2 of the second lens group is -65.81 mm, and the total focal length f of the eyepiece is 17 mm;

[0149] The eyepiece has an exit pupil distance EP of 35 mm to 45 mm, and an exit pupil diameter ED of 4 mm to 8 mm;

[0150] The F number (aperture) of the eyepiece is 2.125 to 4.25;

[0151] The image height h of the eyepiece is 9.2 mm to 12.6 mm.

[0152] Table 1 shows the optical parameters of each lens in the eyepiece, which are as follows.

[0153] Table 1

[0154]

[0155] Example 2

[0156] The eyepiece provided in this embodiment 2 has the same optical structure as that of the above-mentioned embodiment 1, which can be seen in Figure 1 The differences are:

[0157] Wherein, the focal length F1 of the first lens group is 22.24 mm, the focal length F2 of the second lens group is -476 mm, and the total focal length f of the eyepiece is 17 mm;

[0158] The eyepiece has an exit pupil distance EP of 35 mm to 45 mm, and an exit pupil diameter ED of 4 mm to 8 mm;

[0159] The F number (aperture) of the eyepiece is 2.125 to 4.25;

[0160] The image height h of the eyepiece is 9.2 mm to 12.4 mm.

[0161] The optical parameters of each lens in the eyepiece are shown in Table 2.

[0162] Table 2

[0163]

[0164]

[0165] According to the eyepieces provided in the above-mentioned embodiments 1 and 2, the optical performance thereof is as follows: Figures 2 to 5 As shown: Figure 2 is a schematic diagram of the point diagram. Figure 3 is the MTF curve graph, Figure 4 is the field curvature distortion diagram, Figure 5 This is the vertical axis chromatic aberration diagram.

[0166] See also Figure 2 In the eyepieces provided in Example 1 and Example 2, the maximum value of the image point in the point array diagram is less than 30 μm.

[0167] See also Figure 3 , the eyepieces provided in Example 1 and Example 2 have an MTF of >0.2 at 14lp / mm.

[0168] See also Figure 4For the eyepieces provided in Example 1 and Example 2, the maximum distortion occurs in 1 field of view, and the absolute value is less than 14%, which is very small.

[0169] See also Figure 5 The eyepieces provided in Example 1 and Example 2 have a maximum chromatic aberration value of less than 3 μm.

[0170] According to another embodiment of the present application, an eyepiece optical system is provided, which includes the eyepiece as described above.

[0171] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0172] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An eyepiece, characterized in that: It comprises a first lens group and a second lens group arranged along the same optical axis, wherein the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side; The first lens group comprises a first lens (1), a second lens (2) and a third lens (3) which are arranged in sequence along the optical axis; The second lens group comprises a fourth lens (4), a fifth lens (5) and a sixth lens (6) which are arranged in sequence along the optical axis; The eyepiece satisfies: 0.049<n1 / f1+n2 / f2+n3 / f3+n4 / f4+n5 / f5+n6 / f6<0.08; wherein n1-n6 are the refractive indices of the first lens (1) to the sixth lens (6), and f1-f6 are the focal lengths of the first lens (1) to the sixth lens (6).

2. The eyepiece according to claim 1, characterized in that The eyepiece satisfies: 0.65<(EP×ED) / (f×h)<2.3; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

3. The eyepiece according to claim 1, characterized in that The fourth lens (4), the fifth lens (5) and the sixth lens (6) are glued together in sequence to form a glued lens group.

4. The eyepiece according to claim 3, characterized in that The fourth lens (4) and the sixth lens (6) both have positive refractive power, and the fifth lens (5) has negative refractive power.

5. The eyepiece according to claim 4, characterized in that The first lens (1), the second lens (2) and the third lens (3) all have positive refractive power.

6. The eyepiece according to any one of claims 1 to 5, characterized in that: The eyepiece satisfies: 0.042<(1 / F1)+(1 / F2)<0.08; wherein F1 is the focal length of the first lens group, and F2 is the focal length of the second lens group.

7. The eyepiece according to claim 6, characterized in that The eyepiece satisfies: 1.19<F1 / f<1.3; wherein F1 is the focal length of the first lens group, and f is the total focal length of the eyepiece.

8. The eyepiece according to claim 3, characterized in that The fourth lens (4) is a biconvex lens, the fifth lens (5) is a biconcave lens, and the sixth lens (6) is a concave-convex lens.

9. The eyepiece according to claim 8, characterized in that The first lens (1) is a biconvex lens, the second lens (2) is a plano-convex lens, and the third lens (3) is a convex-concave lens.

10. The eyepiece according to claim 2, characterized in that The exit pupil distance EP of the eyepiece is 35 mm to 45 mm, the exit pupil diameter ED of the eyepiece is 4 mm to 8 mm, and the F number of the eyepiece is 2.125 to 4.

25.

11. The eyepiece according to claim 2, characterized in that The image height of the eyepiece is 9.2 mm to 12.6 mm.

12. An eyepiece optical system, characterized in that: include: An eyepiece as claimed in any one of claims 1 to 11.

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