Lens module and optical lens

Abstract

The embodiment of the invention provides a lens module and an optical lens. The lens module comprises an eyepiece, and the eyepiece comprises a first lens group, a second lens group and a third lens group which are sequentially arranged along the same optical axis of an exit pupil side; the first lens group comprises a first lens; the second lens group comprises a second lens, a third lens and a fourth lens which are glued in sequence, both the second lens and the fourth lens have positive focal power, and the third lens has negative focal power; and the third lens group comprises a fifth lens and a sixth lens which are glued with each other, the fifth lens has positive focal power, and the sixth lens has negative focal power.

Description

Technical Field

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

[0002] Modern observation and aiming equipment needs to meet the multiple needs of observers. Among them, a large pupil distance is one of the key factors to improve observation comfort, and a shorter focal length can help significantly reduce the length of the lens of the observation and aiming equipment, thereby improving its portability. In addition, high definition enables observers to see more details of the target object, which is crucial to improving the observation effect. At present, the lenses of mainstream observation and aiming equipment generally have an pupil distance of 4mm-6mm, and the focal length mostly exceeds 30mm. Such a design limits the portability and observation comfort of the observation and aiming equipment. In order to aim at the observation target, users often need to adjust their posture or position, which not only affects the observation efficiency, but also reduces the user experience. Summary of the invention

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

[0004] In a first aspect, the present application provides a lens module. The lens module includes an eyepiece;

[0005] The eyepiece comprises a first lens group, a second lens group and a third lens group which are arranged in sequence along the same optical axis on the exit pupil side;

[0006] The first lens group includes a first lens;

[0007] The second lens group includes a second lens, a third lens, and a fourth lens that are glued together in sequence, the second lens and the fourth lens both have positive focal power, and the third lens has negative focal power;

[0008] The third lens group includes a fifth lens and a sixth lens cemented to each other, wherein the fifth lens has positive focal power, and the sixth lens has negative focal power.

[0009] Optionally, the eyepiece satisfies: 4.4≤(F1+F2) / f≤4.6; wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and f is the total focal length of the eyepiece.

[0010] Optionally, the second lens group satisfies: 3.1≤|(f2+f4) / f3|≤3.3; wherein f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens.

[0011] Optionally, the third lens group satisfies: 1.6≤|f5 / f6|≤1.9; wherein f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens.

[0012] Optionally, the eyepiece satisfies: 1.2≤|F3 / F2|≤1.8; wherein F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group.

[0013] Optionally, the optical effective aperture D of the largest lens in the eyepiece max The image height h of the eyepiece satisfies: 3.6≤D max / h≤4.3.

[0014] Optionally, the first lens has positive optical power.

[0015] Optionally, the optical focal length of the first lens group is positive, the optical focal length of the second lens group is positive, and the optical focal length of the third lens group is negative.

[0016] Optionally, the first lens is a biconvex lens.

[0017] Optionally, the second lens is a biconvex lens, the third lens is a biconcave lens, and the fourth lens is a biconvex lens.

[0018] Optionally, the fifth lens and the sixth lens are convex-concave lenses.

[0019] Optionally, the lens module further includes an objective lens system, and the objective lens system is located on a side of the eyepiece away from an exit pupil side.

[0020] Optionally, when the light received by the objective lens system is infrared light, the lens module further includes a display screen, and the display screen is located between the third lens group and the objective lens system.

[0021] Optionally, a reticle mark is displayed on the display screen;

[0022] The objective lens system includes a shooting device, which is electrically connected to the display screen, and the target image shot by the shooting device can be displayed through the display screen.

[0023] Optionally, when the light received by the objective lens system is visible light, the objective lens system is located on a side of the third lens group away from the exit pupil side, and the objective lens system and the third lens group are spaced apart.

[0024] In a second aspect, the present application provides an optical lens. The optical lens comprises:

[0025] casing; and

[0026] A lens module as described in the first aspect.

[0027] The beneficial effects of this application are:

[0028] The lens module provided in the embodiment of the present application is a short-focal-length, high-definition sighting lens design. The lens module of the present application has a longer exit pupil distance, can achieve a higher-definition imaging effect, and obtain high-quality images; at the same time, the optical structure of the entire lens module is compact and has a wide range of applications.

[0029] 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

[0030] 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.

[0031] Figure 1 A schematic diagram of the structure of the lens module provided in an embodiment of the present application;

[0032] Figure 2 A dot array diagram of a lens module provided in an embodiment of the present application;

[0033] Figure 3 MTF diagram of the lens module provided in the embodiment of the present application;

[0034] Figure 4 Distortion and field curvature diagram of the lens module provided in the embodiment of the present application;

[0035] Figure 5 This is a vertical axis chromatic aberration diagram of the lens module provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Objective lens system; 8. Display screen. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] 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.

[0043] The lens module and optical lens provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0044] According to an embodiment of the present application, a lens module is provided. Figure 1 The lens module includes an eyepiece, and the eyepiece includes a first lens group, a second lens group and a third lens group arranged in sequence along the same optical axis on the exit pupil side; the first lens group includes a first lens 1; the second lens group includes a second lens 2, a third lens 3 and a fourth lens 4 glued together in sequence, and the second lens 2 and the fourth lens 4 both have positive optical power, and the third lens 3 has negative optical power; the third lens group includes a fifth lens 5 and a sixth lens 6 glued together, and the fifth lens 5 has positive optical power, and the sixth lens 6 has negative optical power.

[0045] The lens module proposed in the embodiment of the present application is a short-focus, high-definition sighting lens design that can also have a long pupil distance, and has a wide range of applications. In particular, the present application has a new design of the optical structure and parameters for the eyepiece in the lens module.

[0046] See also Figure 1 The exit pupil distance refers to the distance from the position of the exit pupil of the lens module provided in the embodiment of the present application (i.e., the position where the observer's eyes should be placed) to the surface of the last lens (i.e., the sixth lens 6) of the lens module.

[0047] Since the lens module provided in the embodiment of the present application has the characteristics of short focal length and high definition, it is very suitable for use in observation and aiming equipment, such as telescopes.

[0048] For outdoor sports enthusiasts, a high-quality sighting device is essential. The lens module of the present application can not only provide a clear field of view, but also has a compact structure, is light, and is easy to carry and use, so it is very suitable as an accessory for outdoor sports equipment.

[0049] In the field of security monitoring, high-definition sighting lenses can capture more details, thereby improving the accuracy and reliability of monitoring. The high-definition imaging effect of the lens module of the present application makes it a better choice for security monitoring equipment.

[0050] In the field of scientific research and measurement, precise optical instruments are indispensable. The high definition and short focal length characteristics of the lens module of the present application make it an ideal tool for precision measurement and observation.

[0051] The lens module provided in the embodiment of the present application, from the perspective of its optical architecture, see Figure 1 The lens module includes an eyepiece, and the eyepiece includes three lens groups: a first lens group, a second lens group, and a third lens group, which are arranged in sequence along the same optical axis; wherein 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 and the third lens group are arranged in sequence on the side of the first lens group away from the exit pupil side. This layout ensures that the light can maintain a stable path when passing through each lens group, thereby reducing aberrations and distortions, which is conducive to achieving clear imaging.

[0052] In the eyepiece provided in the present application, the first lens group is located on the exit pupil side, so that the observer's eyes can be comfortably aligned with the eyepiece and receive a clear, distortion-free image. The first lens group in the present application may include only one lens, namely Figure 1 The first lens 1 is shown in FIG.

[0053] In the eyepiece provided in the present application, the second lens group includes a second lens 2, a third lens 3 and a fourth lens 4 glued together in sequence. Among these three lenses, the second lens 2 and the fourth lens 4 both have positive optical power, and the third lens 3 located between the two lenses has negative optical power.

[0054] The second lens 2 and the fourth lens 4 both have positive focal power, that is, they have a converging effect on light. The third lens 3 has a negative focal power, that is, it has a diverging effect on light. This combination of positive and negative focal powers helps to finely control the light to achieve high-quality imaging. In addition, through the gluing technology, the air gap between the three lenses is eliminated, effectively reducing stray light and reflection, thereby improving the overall light transmission performance and imaging quality.

[0055] In the eyepiece provided in the present application, the third lens group is mainly composed of the fifth lens 5 and the sixth lens 6 fixed together by gluing, which forms a compact double-glued lens group. The gluing design helps to reduce the air space between the lenses, thereby reducing aberrations and distortions and improving imaging quality. In addition, through the design of mutually glued lenses, the third lens group achieves structural compactness. This helps to reduce the overall length and weight of the entire lens module and improve portability.

[0056] For the third lens group, from the perspective of the focal power combination of the lenses included: the fifth lens 5 has a positive focal power and has a converging effect on light; the sixth lens 6 has a negative focal power and has a diverging effect on light. Among them, the fifth lens 5 and the fourth lens 4 (located in the second lens group) are adjacent and spaced apart. The combination of positive and negative focal powers in the third lens group helps to balance the imaging performance of the eyepiece of the present application, thereby improving the imaging performance of the entire lens module, so that a clear image can be formed. In addition, the combination of positive and negative focal powers enables the third lens group to provide sufficient back focal length without increasing the length of the lens, so as to meet the design requirements of the short-focus lens.

[0057] The third lens group, the first lens group and the second lens group form the eyepiece provided in this application. The first lens group is closest to the exit pupil side and is used to focus or correct the light. The design of the first lens group is coordinated with the subsequent lens groups to ensure that the light can pass through the entire eyepiece smoothly. Specifically, the design of the second lens group helps to further adjust the path and focal point of the light to achieve high-quality imaging. The third lens group cooperates with the first lens group and the second lens group to focus and adjust the light passing through the first two lens groups. By working in coordination with the first lens group and the second lens group, the third lens group can ensure that the light is accurately focused on the imaging surface, thereby obtaining a clear image.

[0058] In the lens module provided in the embodiment of the present application, the number of lenses included in the design of the eyepiece part is not specifically limited, and can be flexibly adjusted and optimized according to the application requirements. In other words, the eyepiece provided in the present application includes but is not limited to 6 lenses.

[0059] In other words, the first lens group has at least one lens, the second lens group has at least three lenses, and the third lens group has at least two lenses. Figure 1 The lens configuration shown is fully capable of meeting the optical design requirements of short focal length and high definition.

[0060] The lens module provided in the embodiment of the present application, wherein the eyepiece is effectively reduced in aberration and distortion and significantly improves the imaging quality through the combination of specially designed first lens group, second lens group and third lens group, especially the combination of positive and negative optical focal lengths of the lenses in the second lens group and the third lens group.

[0061] The lens module provided in the embodiment of the present application has a compact structure, wherein the eyepiece is provided by sequentially arranging lens groups along the same optical axis and adopting a cemented lens method. The use of cemented lenses reduces the air space between lenses, further reduces optical aberrations, and makes the image clearer. The cemented lens method also effectively shortens the length of the eyepiece. This compact design facilitates the integration of the eyepiece or the lens module containing the eyepiece into smaller devices, such as telescopes and other sighting devices, thereby expanding the scope of application.

[0062] Through reasonable lens combination and focal length matching, the lens module provided in the embodiment of the present application realizes high-definition imaging at short focal length. This short focal length design not only improves the flexibility of imaging, but also enables the lens module to provide a wide field of view and clear images in a limited space.

[0063] In summary, the lens module provided in the embodiments of the present application achieves a combination of short focal length, high definition and long exit pupil distance.

[0064] In some examples of this application, see Figure 1 , the eyepiece satisfies: 4.4≤(F1+F2) / f≤4.6; wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and f is the total focal length of the eyepiece.

[0065] In this example of the present application, in order to further improve the optical performance of the eyepiece, a ratio range between the focal length F1 of the first lens group, the focal length F2 of the second lens group and the total focal length f of the eyepiece is specially designed, that is, it satisfies: 4.4≤(F1+F2) / f≤4.6. The focal length ratio provided in this example of the present application can enable the eyepiece (or lens module) to achieve a short focal length design while maintaining high definition, thereby meeting the needs of specific application scenarios.

[0066] In the eyepiece provided in the present application, the focal length F1 of the first lens group mainly affects the light reception and imaging quality on the exit pupil side. By adjusting the size of F1, the comfort of the observer's eyes can be optimized while ensuring the clarity and contrast of the imaging.

[0067] In the eyepiece provided in the present application, the focal length F2 of the second lens group plays a key role in the convergence of light and the sharpness of the image. By accurately setting the value of F2, the contrast of the image can be enhanced, the aberration and distortion can be reduced, and the overall image quality can be improved.

[0068] The total focal length f of the eyepiece is an important parameter for the overall imaging quality. By adjusting the ratio range of (F1+F2) / f, the total focal length of the eyepiece can be adjusted, thereby optimizing the position of the imaging surface and the imaging quality, which is conducive to achieving high-definition imaging even when achieving short focus.

[0069] It can be seen that by setting the ratio of (F1+F2) / f in the range of 4.4 to 4.6, it is ensured that the focal length designs of the first lens group and the second lens group reach a balanced state in the total focal length of the eyepiece. This range has a specific technical effect for the design of short-focus, high-definition eyepieces.

[0070] By controlling the ratio of the sum of the focal lengths of the first lens group and the second lens group to the total focal length of the eyepiece, the propagation path of light inside the eyepiece can be more effectively managed, reducing the generation of aberrations, thereby improving the clarity of the image. The ratio range provided in this example of the present application helps to balance the magnification and aberration correction of each lens group in the eyepiece, ensuring that the image in the entire field of view can meet high-definition standards. Short-focal-length eyepieces are particularly important in sighting devices because they can provide a wider field of view and faster focusing speed.

[0071] When (F1+F2) / f is less than 4.4, the sum of the focal lengths of the first lens group and the second lens group accounts for a relatively small proportion of the total focal length f of the eyepiece, which may result in a decrease in imaging quality, such as reduced image clarity and increased aberrations and distortions.

[0072] See also Figure 1 , the first lens group is located on the exit pupil side, and its focal length F1 directly affects the comfort of the observer's eyes. When F1 is too small, it may cause the observer's eyes to have difficulty aligning the eyepiece, or feel eye fatigue and discomfort during use. The second lens group can be used to converge light and enhance the contrast of the image. When the value of (F1+F2) / f is less than 4.4, if the focal length F2 of the second lens group is also reduced accordingly, it may lead to insufficient light convergence ability, thereby affecting the image quality.

[0073] When the value of (F1+F2) / f is greater than 4.6, the sum of the focal lengths of the first lens group and the second lens group accounts for a larger proportion of the total focal length f of the eyepiece. This may cause the overall focal length of the eyepiece to be too long, which is not conducive to a short focal length design, thereby increasing the volume size of the eyepiece, which is not conducive to portability and lightweight design. A focal length ratio that is too large may also cause the position of the imaging surface to shift, making it difficult for the observer to accurately capture the target image, which will affect the observation effect and accuracy of the eyepiece. In addition, a larger focal length ratio will also increase aberrations.

[0074] It can be seen that a focal length ratio of (F1+F2) / f less than 4.4 or greater than 4.6 may cause many problems, including reduced image quality, reduced observer eye comfort, insufficient light convergence ability, excessive focal length, image plane position offset, etc. Therefore, in the lens module provided in the embodiment of the present application, a new focal length ratio design is particularly carried out for the eyepiece therein, and it is crucial to control the focal length ratio range of 4.4≤(F1+F2) / f≤4.6.

[0075] In some examples of the present application, the second lens group satisfies: 3.1≤|(f2+f4) / f3|≤3.3; wherein f2 is the focal length of the second lens 2, f3 is the focal length of the third lens 3, and f4 is the focal length of the fourth lens 4.

[0076] By setting the range of |(f2+f4) / f3| to 3.1 to 3.3, the focal lengths of the three lenses included in the second lens group are reasonably regulated in this example of the present application. This design aims to optimize the imaging performance of the second lens group and ensure that light can form a good image quality after passing through the lens group.

[0077] In the second lens group, the control of the focal length ratio helps to ensure the performance stability of the eyepiece provided in the present application under different environmental conditions (such as temperature and humidity changes). This is because the change of the focal length ratio will directly affect the imaging performance of the eyepiece, and a reasonable ratio range can reduce this influence, so that the eyepiece can maintain a consistent imaging effect under various conditions.

[0078] The ratio in this example of the present application contains the absolute value sign, and no matter whether the signs of (f2+f4) and f3 are the same, the ratio needs to meet the given range. This reflects that when considering the focal length relationship, not only the numerical value is paid attention to, but also the influence of the positive and negative optical focal length on the imaging is considered.

[0079] As an important component of the eyepiece in the present application, the performance of the second lens group directly affects the overall performance of the eyepiece, and further affects the performance of the entire lens module. By optimizing the focal length ratio of each lens in the second lens group, the overall performance of the eyepiece can be improved, such as improving resolution, increasing field of view, reducing distortion, etc.

[0080] When the value of |(f2+f4) / f3| is less than 3.1, it means that the sum of the focal lengths of the second lens 2 and the fourth lens 4 is too small relative to the focal length of the third lens 3. This will result in that the light cannot be fully refracted and focused when passing through the second lens group, thereby affecting the image quality. For example, the image clarity is reduced and the aberration is increased.

[0081] When the value of |(f2+f4) / f3| is greater than 3.3, it means that the sum of the focal lengths of the second lens and the fourth lens is too large relative to the focal length of the third lens. This will lead to excessive correction of aberrations, thereby introducing new aberration problems. The unreasonable focal length ratio will also lead to uneven spatial distribution inside the eyepiece. In order to meet the imaging requirements, it may be necessary to increase the number or thickness of lenses, resulting in an increase in the volume and weight of the entire eyepiece, which in turn causes the entire lens module to be larger and heavier. This is not only not conducive to the portability and lightweight design of the optical lens, but may also increase manufacturing costs.

[0082] It can be seen that the design of the focal length ratio of 3.1≤|(f2+f4) / f3|≤3.3 is crucial to the imaging quality and performance of short-throw high-definition sighting lenses. When the value of |(f2+f4) / f3| is less than 3.1 or greater than 3.3, it will lead to problems such as reduced image quality, unstable eyepiece performance, over-corrected aberrations, and increased eyepiece volume.

[0083] The focal length ratio of the second lens group mentioned in this example of the present application, 3.1≤|(f2+f4) / f3|≤3.3, brings about technical effects such as optimizing imaging quality, enhancing the stability of eyepiece performance, and improving the overall performance of the lens. These effects together constitute the important characteristics of the short-focus, high-definition sighting lens, enabling it to meet the needs of various complex application scenarios.

[0084] In some examples of the present application, the third lens group satisfies: 1.6≤|f5 / f6|≤1.9; wherein f5 is the focal length of the fifth lens 5 , and f6 is the focal length of the sixth lens 6 .

[0085] The third lens group is a double-cemented lens group, see Figure 1 , which includes a fifth lens 5 and a sixth lens 6. When the fifth lens 5 has a positive focal power and the sixth lens 6 has a negative focal power, the combination of the two can effectively eliminate aberrations and make the image clearer. The double-cemented lens can better control the propagation path of light, so that more light can pass through the eyepiece and be captured by the imaging surface. This helps to improve the light utilization rate of the eyepiece and further improve the imaging quality. On this basis, the design of controlling the focal length ratio of the fifth lens 5 and the sixth lens 6, i.e., |f5 / f6|, to 1.6 to 1.9 helps to ensure the performance stability of the eyepiece under different environmental conditions. When the fifth lens 5 and the sixth lens 6 are bonded, the optical performance of the two is more stable and is not easily affected by external factors such as temperature and humidity. At the same time, a reasonable focal length ratio can further reduce the impact of environmental factors on the imaging performance of the lens, so that the lens can maintain a consistent imaging effect under various conditions.

[0086] Under the premise of ensuring high-quality imaging, by reasonably controlling the focal length ratio of the two lenses in the third lens group, the volume and imaging quality of the entire eyepiece can be balanced to a certain extent. The focal length ratio range in this example of the present application means that the relative position relationship between the fifth lens 5 and the sixth lens 6 is more compact, which helps to reduce the overall volume of the eyepiece and improve the portability and lightweight design of the eyepiece. In this way, the miniaturization of the entire lens module can be achieved.

[0087] In this example of the present application, by reasonably controlling the focal length ratio of the two lenses in the third lens group and adopting a cemented lens design, the volume of the eyepiece and the imaging quality can be balanced to a certain extent. A smaller focal length ratio range means that the relative position relationship between the lenses is more compact, which helps to reduce the overall volume of the lens and improve the portability and lightness of the lens.

[0088] When the value of |f5 / f6| is less than 1.6, it means that the focal length of the fifth lens 5 is too small relative to the focal length of the sixth lens 6. This will cause the light to be unable to be fully refracted and focused when passing through the third lens group, thereby affecting the image quality. For example, the image clarity is reduced, the aberration is increased, and the image may be distorted or distorted.

[0089] When the value of |f5 / f6| is greater than 1.9, it means that the focal length of the fifth lens 5 is too large relative to the focal length of the sixth lens 6. This will lead to over-correction of aberrations, thereby introducing new aberration problems. In addition, the unreasonable focal length ratio may lead to uneven spatial distribution inside the eyepiece. In order to meet the imaging requirements and maintain a reasonable focal length ratio, it may be necessary to increase the number or thickness of the lenses, resulting in an increase in the volume of the eyepiece. This is not only not conducive to the portability and lightweight design of the eyepiece, but may also increase the manufacturing cost of the eyepiece.

[0090] It can be seen that the design of the focal length ratio range of 1.6≤|f5 / f6|≤1.9 is crucial to the imaging quality and overall performance of the short-focus high-definition eyepiece. When the value of |f5 / f6| is less than 1.6 or greater than 1.9, it may lead to many problems such as decreased imaging quality, unstable performance of the lens module, increased design difficulty, over-corrected aberrations, and increased size of the lens module. Therefore, in the design and manufacturing process of the eyepiece, this focal length ratio range should be controlled to ensure that the formed eyepiece or the lens module containing the eyepiece has high-quality imaging quality and stable performance.

[0091] In some examples of the present application, the eyepiece satisfies: 1.2≤|F3 / F2|≤1.8; wherein F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group.

[0092] The second lens group and the third lens group both include lenses with negative optical power. Reasonable setting of the focal length ratio between F3 and F2 helps to balance the optical power distribution of the entire eyepiece and also helps to reduce aberrations, thereby improving the imaging quality of the eyepiece group.

[0093] The focal length ratio range provided in this example of the present application is 1.2≤|F3 / F2|≤1.8, which provides a wider adaptability for the entire eyepiece. This range allows the eyepiece to maintain stable imaging performance at different focal lengths, thereby meeting the needs of various application scenarios.

[0094] Under the premise of ensuring high-quality imaging, the volume and weight of the eyepiece can be reduced to a certain extent by reasonably controlling the focal length ratio of the second lens group and the third lens group and introducing a negative focal power lens.

[0095] When the value of |F3 / F2| is less than 1.2, it means that the focal length of the third lens group is too short relative to the second lens group. This will cause the light to be unable to be fully converged or diverged when passing through the third lens group, thereby affecting the image quality. Specifically, the image may be blurred, the aberration may increase, and other problems. The shorter focal length of the third lens group may cause the field of view of the eyepiece to become smaller, limiting the shooting range of the eyepiece. In addition, in order to achieve high-quality imaging at a smaller focal length ratio, it may be necessary to increase the number or thickness of the lenses, resulting in an increase in the volume and weight of the eyepiece.

[0096] When the value of |F3 / F2| is greater than 1.8, it means that the focal length of the third lens group is too long relative to the second lens group, which will cause a large aberration when the light passes through the third lens group, thereby affecting the clarity of the image.

[0097] It can be seen that in this example of the present application, the design of 1.2≤|F3 / F2|≤1.8 is based on a comprehensive consideration of the performance of the eyepiece and the image quality. Exceeding this range may lead to problems such as reduced image quality, limited field of view, increased difficulty in lens design, increased lens volume and weight, and increased aberrations.

[0098] In this example of the present application, the design of 1.2≤|F3 / F2|≤1.8, combined with the introduction of negative focal lenses in the second lens group and the third lens group, together constitute the important characteristics of short-focus, high-definition sighting lenses. These designs help to optimize imaging quality, enhance eyepiece adaptability, improve eyepiece design flexibility, improve eyepiece volume and weight, and improve eyepiece stability. These effects together enable the eyepiece to meet the needs of various complex application scenarios and provide users with a better imaging experience.

[0099] In some examples of this application, see Figure 1, the optical effective aperture D of the largest lens in the eyepiece max The image height h of the eyepiece satisfies: 3.6≤D max / h≤4.3.

[0100] By controlling D max The ratio to h is between 3.6 and 4.3, which ensures that the light projected into the eyepiece can form a clear and sharp image after passing through each lens group.

[0101] Larger D max It helps to collect more light, while the image height h of the appropriate eyepiece ensures the resolution of the imaging. The combination of the two achieves high-definition imaging effects.

[0102] Within this ratio range of the example of the present application, the eyepiece can effectively utilize light and reduce light loss and aberration. When light passes through the lens group in the eyepiece, it will be refracted and focused, and a reasonable D max The h ratio ensures that the light is focused in the best possible way, resulting in a high-quality image.

[0103] That is, by controlling the optical effective aperture D of the largest lens in the eyepiece max The ratio between the image height h of the eyepiece is between 3.6 and 4.3, which can achieve technical effects such as high-definition imaging, optimized light utilization, short focal length design, wide field of view, good manufacturability and reliability. These effects together improve the overall performance and application value of the eyepiece.

[0104] When D max When the value of / h is less than 3.6, the problem that may arise is that the image clarity decreases. This is because the smaller D max It may mean that the lens's ability to collect light is limited, resulting in uneven light distribution or insufficient light on the focal plane. This may cause the edges of the image to become blurred, reducing the overall image clarity. Due to the small diameter of the lens, more light may be lost when passing through the lens, especially when the light enters the lens at an angle, which will reduce the efficiency of light utilization and affect the brightness and contrast of the image.

[0105] In order to maintain a certain imaging quality, when D max When the focal length of the lens is smaller, it is necessary to increase the focal length of the lens to compensate for the lack of light collection ability. This will increase the overall size of the eyepiece, which in turn affects the volume of the entire lens module.

[0106] When D maxWhen the value of / h is greater than 4.3, the possible problem is increased aberration, which will reduce the fineness and resolution of the image and affect the observation effect. A larger lens aperture requires a higher precision processing and assembly process, which will increase the manufacturing cost of the lens; at the same time, a larger lens also means that more materials are required, further increasing the cost. In addition, a larger lens aperture and focal length may cause the overall weight of the lens module to increase.

[0107] It can be seen that when D max When the ratio of / h is less than 3.6 or greater than 4.3, it may have an adverse effect on the eyepiece of the present application, and even the imaging quality, light utilization, focal length design, etc. of the lens module. Therefore, when designing the eyepiece, it is necessary to comprehensively consider multiple factors to ensure the overall performance of the lens module including the eyepiece. The ratio range in this example of the present application is a relatively reasonable choice, which can take into account factors such as the size, weight and cost of the lens module while ensuring the imaging quality.

[0108] In some examples of the present application, the first lens 1 has positive optical power.

[0109] See also Figure 1 The first lens 1 is located on the exit pupil side of the entire lens module. It has positive optical power and can guide light to focus on the center, providing a basis for the subsequent imaging process. By matching the optical power distribution of the first lens group (positive optical power) with the second lens group and the third lens group, the optical power balance of the entire eyepiece can be achieved, thereby ensuring high-quality imaging.

[0110] The first lens 1 with positive refractive power can enhance the convergence ability of light, so that the light can be more accurately focused on the image plane after passing through the lens, which is crucial to improving the imaging clarity and resolution of the eyepiece.

[0111] The eyepiece design of the present application is mainly based on the distribution of optical power to achieve the technical effect of short focus and high definition. The positive optical power design of the first lens 1 is an integral part of this solution. Through the reasonable distribution and synergy of the optical power with other lens groups, it is possible to achieve high-definition imaging performance at a shorter focal length. This can not only improve the shooting effect of the eyepiece, but also reduce the volume and weight of the eyepiece, and improve the portability and practicality of the eyepiece.

[0112] The design of the first lens 1 with positive focal length plays a vital role in the short-focus, high-definition sighting lens. By coordinating with the focal length distribution of the second lens group and the third lens group, the focal length of the entire eyepiece can be balanced and the light convergence ability can be optimized; at the same time, technical effects such as expanding the field of view, controlling aberrations and improving the stability of the eyepiece can also be achieved. These effects jointly achieve the technical goals of short-focus and high-definition, and provide technical support for the design and application of lens modules.

[0113] In some examples of the present application, the optical power of the first lens group is positive, the optical power of the second lens group is positive, and the optical power of the third lens group is negative.

[0114] The focal power is a physical quantity that describes the ability of a lens or lens group to refract light, and its positive or negative value represents the convergence or divergence of the lens or lens group on light. In this example of the present application, the focal power of the first lens group is positive, the focal power of the second lens group is also positive, and the focal power of the third lens group is negative. This configuration realizes a short focal length design of the eyepiece.

[0115] Specifically, the first lens group and the second lens group are both configured with positive focal length, which is conducive to converging light and shortening the total length of the eyepiece. The lens group with positive focal length can effectively converge the light from the observed object to the middle part of the lens, providing a good foundation for the subsequent imaging process. The third lens group is configured with negative focal length, which plays a role in diverging light, helps to further shorten the focal length of the lens, and adjusts the path of light to meet specific imaging requirements.

[0116] This example of the present application can optimize the aberration correction of the lens by properly matching the lens groups with positive and negative optical focal lengths. This configuration helps to reduce the loss and distortion of light during the refraction and reflection process inside the eyepiece, thereby improving the clarity and accuracy of imaging.

[0117] In some examples of the present application, the first lens 1 is a biconvex lens.

[0118] In the eyepiece provided in the present application, the first lens located on the exit pupil side, i.e., the first lens 1, adopts a biconvex lens to enhance the light convergence ability. Specifically, both sides of the biconvex lens are convex, so that the light will be subjected to a stronger refraction effect when passing through the lens, thereby enhancing the light convergence ability. This helps to achieve a clearer imaging effect at a short focal length.

[0119] As the first lens on the exit pupil side, the focal length distribution of the first lens 1 has an important influence on the performance of the entire eyepiece. The design of the biconvex lens can make the first lens 1 have a more suitable positive focal length, providing a good foundation for the focal length distribution and imaging performance of the subsequent lens group.

[0120] In some examples of the present application, the second lens 2 is a biconvex lens, the third lens 3 is a biconcave lens, and the fourth lens 4 is a biconvex lens.

[0121] The eyepiece provided by the present application includes a second lens group located between the first lens group and the third lens group, and the second lens group includes three lenses glued together. The second lens 2 is close to the first lens 1, and the second lens 2 is a double convex lens, which further enhances the light convergence ability, and cooperates with the first lens to enable the eyepiece to maintain a high imaging clarity at a short focal length, which helps to control aberrations and improve the imaging quality of the lens.

[0122] In the second lens group, the third lens 3 is a biconcave lens. The design of the biconcave lens can produce negative optical power, which helps to balance the optical power distribution of the entire eyepiece, further control aberrations, and improve the imaging performance of the eyepiece.

[0123] In the second lens group, the fourth lens 4 is a biconvex lens, which further enhances the light convergence capability, so that the eyepiece can capture more light information at a short focal length, improve the brightness and clarity of the image, and at the same time, it also helps to expand the field of view of the eyepiece.

[0124] In some examples of the present application, the fifth lens 5 and the sixth lens 6 are convex-concave lenses.

[0125] The eyepiece provided by the present application also includes a third lens group, and the third lens group includes a fifth lens 5 and a sixth lens 6 that are glued to each other. The fifth lens 5 and the sixth lens 6 are designed as convex-concave lenses, which can enable the eyepiece to have better focal length adjustment ability and aberration control ability while maintaining a shorter focal length. By adjusting the curvature and thickness of the convex-concave lens, the imaging performance of the eyepiece can be further optimized. In addition, the design of the convex-concave lens helps to enhance the structural stability of the eyepiece, so that the eyepiece can maintain stable imaging performance in a complex light environment.

[0126] The eyepieces provided in this application are Figure 1 , at least including a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a sixth lens 6. Reasonable matching and combination of the above six lenses can produce the following comprehensive effects:

[0127] (1) Achieve high-definition short-focus imaging: By rationally designing the surface shape of each lens and the distribution of optical power between them, high-definition imaging effects can be achieved at short focal lengths.

[0128] (2) Optimizing aberrations: The synergy between lenses can further control aberrations and improve the imaging quality of the eyepiece.

[0129] (3) Reduce focal length: By rationally designing the lens shape and combination, the focal length of the eyepiece can be reduced, and the size and weight of the eyepiece can be reduced, thus achieving a lightweight design of the eyepiece.

[0130] (4) Improve lens stability and durability: Reasonable matching and combination of lenses can enhance the structural stability of the lens and improve the durability and service life of the lens.

[0131] Optionally, the first lens 1 to the sixth lens 6 are all glass spherical lenses.

[0132] Spherical lenses can provide stable imaging performance. In addition, the manufacturing process of spherical lenses is relatively simple, with high production efficiency and low cost, which is suitable for mass production. Glass materials have excellent light transmittance and refractive index stability, which enables lenses made of glass to provide clear, high-quality images.

[0133] Of course, the first lens 1 to the sixth lens 6 may also be partially or entirely made of plastic material. Furthermore, the first lens 1 to the sixth lens 6 may all be aspherical lenses.

[0134] In some examples of this application, see Figure 1 The lens module also includes an objective lens system 7, and the objective lens system 7 is located on a side of the eyepiece away from the exit pupil side.

[0135] In the lens module provided in the embodiment of the present application, the objective lens system 7 is located on the side of the eyepiece away from the exit pupil side, and can receive light from the observed object. By reasonably designing the parameters of the objective lens system 7 (such as focal length, aperture, etc.), the lens module's ability to collect light can be significantly enhanced, thereby increasing the light throughput and brightness of the lens module.

[0136] After the objective lens system 7 is introduced, the optical performance of the lens module can be further improved. The objective lens system 7 can make preliminary adjustments and optimizations to the light, reduce the loss and distortion of the light during the propagation process, and thus improve the imaging quality and clarity of the entire lens module. In particular, the effect of the objective lens system 7 is more obvious in long-distance observation or in a dark environment.

[0137] After the objective lens system 7 is introduced, the application field of the lens module can be further expanded.

[0138] In some examples of the present application, when the light received by the objective lens system 7 is infrared light, the lens module further includes a display screen 8, and the display screen 8 is located between the third lens group and the objective lens system 7.

[0139] When the light received by the objective lens system 7 is infrared light, the lens module can capture and image the infrared light. Infrared imaging technology can be applied to fields such as night observation and thermal imaging. By adding the display screen 8, the infrared imaging results can be displayed in real time, providing users with an intuitive observation experience.

[0140] In some examples of the present application, a graticule mark is displayed on the display screen 8 ; the objective lens system 7 includes a shooting device, the shooting device is electrically connected to the display screen 8 , and the target image shot by the shooting device can be displayed through the display screen 8 .

[0141] The graticule marks displayed on the display screen 8 provide an intuitive reference frame for the user. The user can locate the observation target more accurately through these graticules, especially in scenes that require precise measurement or aiming, and this design can significantly improve the precision and accuracy of observation.

[0142] The electrical connection between the shooting device and the display screen 8 enables the target image shot by the shooting device to be displayed in real time on the display screen 8. This real-time image display function facilitates users to make instant observations and judgments.

[0143] Through the reticle marks and real-time image display function on the display screen 8, the user can observe more intuitively and conveniently. This design not only improves the practicality of the lens module, but also improves the user experience and satisfaction.

[0144] In some examples of the present application, when the light received by the objective lens system is visible light, the objective lens system 7 is located on a side of the third lens group away from the exit pupil side, and the objective lens system 7 and the third lens group are spaced apart.

[0145] When visible light passes through the objective lens system 7, it will be focused and form a clear image on a certain plane, which is the image plane of the objective lens system 7. Since there is a gap between the objective lens system 7 and the third lens group of the eyepiece, this gap provides necessary space for the formation of the image plane.

[0146] According to this example of the present application, the spacing setting allows the light to have a sufficient distance to diffuse and focus after passing through the objective lens system 7, thereby forming a clearer and sharper image plane. The clarity and position of the image plane are crucial to the subsequent imaging process because it directly affects the image quality seen by the observer through the eyepiece; the spacing setting also helps to reduce the optical interference between the objective lens system 7 and the third lens group, which may reduce the imaging quality, and the spacing setting helps to reduce these adverse effects.

[0147] According to another embodiment of the present application, an optical lens is provided, which includes a housing and the lens module as described above.

[0148] The eyepiece in the present application is further described below through Example 1 and Example 2.

[0149] Example 1

[0150] The eyepiece provided in this embodiment 1 is shown in FIG. Figure 1 , which comprises a first lens group, a second lens group and a third lens group which are arranged in sequence along the same optical axis on the exit pupil side;

[0151] The first lens group includes a first lens 1, and the first lens 1 has positive optical power;

[0152] The second lens group includes a second lens 2, a third lens 3 and a fourth lens 4 which are glued together in sequence, the second lens 2 and the fourth lens 4 both have positive refractive power, and the third lens 3 has negative refractive power;

[0153] The third lens group includes a fifth lens 5 and a sixth lens 6 cemented to each other, wherein the fifth lens 5 has positive focal power, and the sixth lens 6 has negative focal power;

[0154] Wherein, the first lens 1 is a biconvex lens, the second lens 2 is a biconvex lens, the third lens 3 is a biconcave lens, the fourth lens 4 is a biconvex lens, the fifth lens 5 and the sixth lens 6 are convex-concave lenses, and the first lens 1 to the sixth lens 6 are all glass spherical mirrors;

[0155] The focal length F1 of the first lens group is 45.5 mm, the focal length F2 of the second lens group is 58.1 mm, and the focal length F3 of the third lens group is -100.2 mm.

[0156] The total focal length f of the eyepiece is 23 mm, and the total length of the system is 31.6 mm;

[0157] The eyepiece has an exit pupil distance of 30 mm and an exit pupil diameter ED of 6 mm;

[0158] The half-image height of the eyepiece (focal plane) is 5.55 mm;

[0159] The optical effective aperture D of the largest lens in the eyepiece max The image height h of the focal plane satisfies: 3.71≤D max / h≤4.2.

[0160] Table 1 shows the optical parameters of each lens in the eyepiece provided in this embodiment 1, which are as follows.

[0161] Table 1

[0162]

[0163] Example 2

[0164] 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:

[0165] The focal length F1 of the first lens group is 40.145 mm, the focal length F2 of the second lens group is 58.13 mm, and the focal length F3 of the third lens group is -73.85 mm.

[0166] The total focal length f of the eyepiece is 22 mm, and the total length of the system is 31.2 mm;

[0167] The eyepiece has an exit pupil distance of 30 mm and an exit pupil diameter ED of 6 mm;

[0168] The half image height of the eyepiece is 5.55 mm;

[0169] The optical effective aperture D of the largest lens in the eyepiece max The image height h of the focal plane satisfies: 3.67≤D max / h≤4.3.

[0170] Table 2 shows the optical parameters of each lens in the eyepiece provided in this embodiment 2, which are as follows.

[0171] Table 2

[0172]

[0173]

[0174] The eyepieces provided in Example 1 and Example 2 have optical properties such as 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 and distortion diagram, Figure 5 This is the vertical axis chromatic aberration diagram.

[0175] 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 6 μm.

[0176] See also Figure 3 , the eyepieces provided in Example 1 and Example 2 have an MTF of >0.3 at 80lp / mm.

[0177] See also Figure 4 For 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 13%, and the distortion is very small.

[0178] See also Figure 5 , the eyepieces provided in Example 1 and Example 2 have a maximum chromatic aberration value of less than 6 μm.

[0179] 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.

[0180] 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. A lens module, characterized in that: The lens module includes an eyepiece; The eyepiece comprises a first lens group, a second lens group and a third lens group which are arranged in sequence along the same optical axis on the exit pupil side; The first lens group comprises a first lens (1); The second lens group comprises a second lens (2), a third lens (3) and a fourth lens (4) which are glued together in sequence, the second lens (2) and the fourth lens (4) both have positive optical power, and the third lens (3) has negative optical power; The third lens group comprises a fifth lens (5) and a sixth lens (6) which are cemented to each other, wherein the fifth lens (5) has positive focal power, and the sixth lens (6) has negative focal power.

2. The lens module according to claim 1, characterized in that: The eyepiece satisfies: 4.4≤(F1+F2) / f≤4.6; wherein F1 is the focal length of the first lens group, F2 is the focal length of the second lens group, and f is the total focal length of the eyepiece.

3. The lens module according to claim 2, characterized in that: The second lens group satisfies: 3.1≤|(f2+f4) / f3|≤3.3; wherein f2 is the focal length of the second lens (2), f3 is the focal length of the third lens (3), and f4 is the focal length of the fourth lens (4).

4. The lens module according to claim 1, characterized in that: The third lens group satisfies: 1.6≤|f5 / f6|≤1.9; wherein f5 is the focal length of the fifth lens (5), and f6 is the focal length of the sixth lens (6).

5. The lens module according to claim 1, characterized in that: The eyepiece satisfies: 1.2≤|F3 / F2|≤1.8; wherein F2 is the focal length of the second lens group, and F3 is the focal length of the third lens group.

6. The lens module according to claim 1, characterized in that: The optical effective aperture D of the largest lens in the eyepiece max The image height h of the eyepiece satisfies: 3.6≤D max / h≤4.

3.

7. The lens module according to any one of claims 1 to 6, characterized in that: The first lens (1) has positive refractive power.

8. The lens module according to claim 7, characterized in that: The optical power of the first lens group is positive, the optical power of the second lens group is positive, and the optical power of the third lens group is negative.

9. The lens module according to claim 7, characterized in that: The first lens (1) is a biconvex lens.

10. The lens module according to claim 9, characterized in that: The second lens (2) is a biconvex lens, the third lens (3) is a biconcave lens, and the fourth lens (4) is a biconvex lens.

11. The lens module according to claim 10, characterized in that: The fifth lens (5) and the sixth lens (6) are convex-concave lenses.

12. The lens module according to claim 1, characterized in that: The lens module also includes an objective lens system (7), and the objective lens system (7) is located on a side of the eyepiece away from the exit pupil side.

13. The lens module according to claim 12, characterized in that: When the light received by the objective lens system (7) is infrared light, the lens module further comprises a display screen (8), and the display screen (8) is located between the third lens group and the objective lens system (7).

14. The lens module according to claim 13, characterized in that: The display screen (8) displays a dividing line mark; The objective lens system (11) comprises a shooting device, which is electrically connected to the display screen (8), and the target image shot by the shooting device can be displayed on the display screen (8).

15. The lens module according to claim 12, characterized in that: When the light received by the objective lens system is visible light, the objective lens system (7) is located on a side of the third lens group away from the exit pupil side, and the objective lens system (7) and the third lens group are arranged at an interval.

16. An optical lens, characterized in that: include: shell; and A lens module as described in any one of claims 1-15.

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