Lens module and optical lens

Abstract

Embodiments of the present application provide a lens module and an optical lens; the lens module comprises an ocular lens, the ocular lens comprises a first lens group, a second lens group and a third lens group arranged in sequence along an optical axis on 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 glued in sequence, the second lens and the fourth lens both have positive refractive power, and the third lens has negative refractive power; the third lens group comprises a fifth lens and a sixth lens glued to each other, and the fifth lens has positive refractive power, and the sixth lens has negative refractive power.

Description

Technical Field

[0001] This application relates to the field of optical technology, and more specifically, to a lens module and an optical lens. Background Technology

[0002] Modern observation and aiming equipment needs to meet multiple needs of observers. A large exit pupil distance is a key factor in improving observation comfort, while a shorter focal length helps to significantly reduce the length of the lens, thus improving portability. Furthermore, high resolution allows observers to see more details of the target object, which is crucial for improving observation results. Currently, the lenses of mainstream observation and aiming equipment generally have an exit pupil distance of 4mm-6mm, and the focal length is mostly over 30mm. This design limits the portability and observation comfort of the equipment. To aim at the target, users often need to adjust their posture or position, which not only affects 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, this application provides a lens module. The lens module includes an eyepiece;

[0005] The eyepiece includes a first lens group, a second lens group, and a third lens group arranged sequentially 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 cemented together in sequence. The second lens and the fourth lens both have positive optical power, and the third lens has negative optical power.

[0008] The third lens group includes a fifth lens and a sixth lens bonded together, wherein the fifth lens has positive optical power and the sixth lens has negative optical power.

[0009] Optionally, the eyepiece satisfies: 4.4≤(F1+F2) / f≤4.6; where 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; where 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; where 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; where 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 relationship between the image height h of the eyepiece and the given image height h satisfies: 3.6 ≤ D max / h≤4.3.

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

[0015] Optionally, 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.

[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 and concave lenses.

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

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

[0021] Optionally, the display screen shows a reticle mark;

[0022] The objective lens system includes an imaging device, which is electrically connected to the display screen. The target image captured by the imaging device can be displayed on the display screen.

[0023] Optionally, when the light received by the objective lens system is visible light, the objective lens system is located on the 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] Secondly, this application provides an optical lens. The optical lens includes:

[0025] The outer casing; and

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

[0027] The beneficial effects of this application are as follows:

[0028] The lens module provided in this application is a short focal length, high definition observation and aiming lens design. The lens module of this application has a long exit pupil distance, which can achieve higher definition imaging effect and acquire 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 this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0031] Figure 1 This is a schematic diagram of the lens module provided in an embodiment of this application;

[0032] Figure 2 A dot array diagram of the lens module provided in the embodiments of this application;

[0033] Figure 3 MTF diagram of the lens module provided in the embodiments of this application;

[0034] Figure 4 Distortion and field curvature diagrams of the lens module provided in the embodiments of this application;

[0035] Figure 5 A transverse chromatic aberration diagram of the lens module provided in this application embodiment.

[0036] Explanation of reference numerals in the attached figures:

[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 Implementation

[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, numerical expressions, and values ​​of the components and steps 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 and is in no way intended to limit the scope of this application and its application or use.

[0040] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

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

[0042] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0043] The lens module and optical lens provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0044] According to one embodiment of this application, a lens module is provided, see [link to embodiment]. Figure 1 The lens module includes an eyepiece, which includes a first lens group, a second lens group, and a third lens group arranged sequentially 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 cemented together in sequence, wherein 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 cemented together, wherein the fifth lens 5 has positive optical power, and the sixth lens 6 has negative optical power.

[0045] The lens module proposed in this application is a short-focal-length, high-definition viewing lens design that also has a long exit pupil distance, and it has a wide range of applications. In particular, this application presents a new design for the optical architecture and parameters of the eyepiece in the lens module.

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

[0047] Because the lens module provided in this 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 aiming device is essential. The lens module of this application not only provides a clear field of view, but also, due to its compact and lightweight structure, is easy to carry and use, making it ideal as an accessory for outdoor sports equipment.

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

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

[0051] The lens module provided in this application embodiment, from its optical architecture perspective, see... Figure 1 The lens module includes an eyepiece, which comprises three lens groups: a first lens group, a second lens group, and a third lens group. These three lens groups are arranged sequentially along the same optical axis. The first lens group is located on the exit pupil side, i.e., the side closer to the observer's eye. The second and third lens groups are sequentially located on the side of the first lens group away from the exit pupil side. This arrangement ensures that light maintains a stable path as it passes through each lens group, thereby reducing aberrations and distortions, which is beneficial for achieving clear imaging.

[0052] In the eyepiece provided in this application, the first lens group is located on the exit pupil side, which allows the observer's eye to be comfortably aligned with the eyepiece and receive a clear, distortion-free image. The first lens group in this application may consist of only one lens. Figure 1 The first lens 1 is shown in the figure.

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

[0054] Both the second lens 2 and the fourth lens 4 have positive optical power, meaning they converge light. The third lens 3 has negative optical power, meaning it diverges light. This combination of positive and negative optical power facilitates precise control of light to achieve high-quality imaging. Furthermore, through cementing technology, the air gaps between the three lenses are eliminated, effectively reducing stray light and reflections, thereby improving overall light transmission and image quality.

[0055] In the eyepiece provided in this application, the third lens group is mainly composed of a fifth lens 5 and a sixth lens 6, which are cemented together to form a compact cemented doublet lens group. The cementing design helps reduce the air gap between the lenses, thereby reducing aberrations and distortion, and improving image quality. Furthermore, the cemented lens design achieves structural compactness in the third lens group. This helps reduce the overall length and weight of the entire lens module, improving portability.

[0056] Regarding the third lens group, in terms of the optical power combination of the included lenses: the fifth lens 5 has positive optical power and converges light; the sixth lens 6 has negative optical power and diverges light. The fifth lens 5 and the fourth lens 4 (located in the second lens group) are adjacent but spaced apart. This combination of positive and negative optical power in the third lens group helps balance the imaging performance of the eyepiece, thereby improving the overall imaging performance of the lens module and enabling the formation of a clear image. Furthermore, this combination of positive and negative optical power allows the third lens group to provide sufficient back focal length without increasing the lens length, meeting the design requirements of a short-focal-length lens.

[0057] The third lens group, in combination with the first and second lens groups, forms the eyepiece provided in this application. The first lens group, located closest to the exit pupil, is used to focus or correct light. Its design coordinates with subsequent lens groups to ensure light can pass smoothly through the entire eyepiece. 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, working in conjunction with the first and second lens groups, focuses and adjusts the light passing through the first two lens groups. Through its collaborative work with the first and second lens groups, the third lens group ensures that light is accurately focused on the imaging plane, resulting in a clear image.

[0058] In the lens module provided in this application embodiment, the number of lenses included in the eyepiece design is not specifically limited and can be flexibly adjusted and optimized according to application requirements. That is to say, the eyepiece provided in this 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. It should be noted that, see [link to relevant documentation]. Figure 1 The lens configuration shown is fully capable of meeting the optical design requirements of short focal length and high resolution.

[0060] The lens module provided in this application embodiment has an eyepiece that uses a specially designed combination of a first lens group, a second lens group, and a third lens group. In particular, the positive and negative optical powers of the lenses in the second lens group and the third lens group are matched to effectively reduce aberrations and distortions and significantly improve the imaging quality.

[0061] The lens module provided in this application has a compact structure, wherein the eyepiece is constructed by sequentially arranging lens groups along the same optical axis and employing a cemented lens method. The use of cemented lenses reduces the air gap between lenses, further reducing optical aberrations and resulting in clearer imaging. 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 observation and aiming equipment, thus expanding its application range.

[0062] By combining lenses and adjusting optical power appropriately, the lens module provided in this application achieves high-resolution imaging at short focal lengths. This short focal length design not only improves imaging flexibility but also enables the lens module to provide a wide field of view and clear images within a limited space.

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

[0064] See some examples in this application. Figure 1 The eyepiece satisfies: 4.4≤(F1+F2) / f≤4.6; where 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 application, to further improve the optical performance of the eyepiece, a specific ratio range is designed 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, namely, satisfying: 4.4 ≤ (F1 + F2) / f ≤ 4.6. The focal length ratio provided in this example of the application allows the eyepiece to maintain high definition while achieving a short focal length design for the eyepiece (or lens module), thereby meeting the needs of specific application scenarios.

[0066] In the eyepiece provided in this application, the focal length F1 of the first lens group mainly affects the light reception and image 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 sharpness and contrast of the image.

[0067] In the eyepiece provided in this application, the focal length F2 of the second lens group plays a crucial role in light convergence and image sharpness. By precisely setting the value of F2, the contrast of the image can be enhanced, aberrations and distortions can be reduced, thereby improving the overall image quality.

[0068] The total focal length f of the eyepiece is an important parameter for overall image quality. By adjusting the range of the ratio (F1+F2) / f, the total focal length of the eyepiece can be adjusted, thereby optimizing the position of the imaging plane and the image quality. This is beneficial for achieving high-definition imaging even with a short focal length.

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

[0070] By controlling the ratio of the sum of the focal lengths of the first and second lens groups to the total focal length of the eyepiece, the propagation path of light within the eyepiece can be managed more effectively, reducing aberrations and thus improving image clarity. The ratio range provided in this example helps balance the magnification and aberration correction of each lens group in the eyepiece, ensuring that the image achieves high definition across the entire field of view. Short focal length eyepieces are particularly important in observation and aiming devices because they 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 and second lens groups is a smaller percentage of the total focal length f of the eyepiece. This may lead to a decrease in image quality, such as reduced image sharpness and increased aberrations and distortion.

[0072] See Figure 1 The first lens group is located on the exit pupil side, and its focal length F1 directly affects the observer's eye comfort. When F1 is too small, it may be difficult for the observer to align their eye with the eyepiece, or they may experience eye fatigue and discomfort during use. The second lens group is used to converge light and enhance image contrast. However, 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 result in insufficient light converging ability, thus affecting image quality.

[0073] When the value of (F1+F2) / f is greater than 4.6, the sum of the focal lengths of the first and second lens groups is disproportionately large relative to the total focal length f of the eyepiece. This may result in an excessively long overall focal length of the eyepiece, hindering the implementation of short focal length designs and increasing the size of the eyepiece, which is detrimental to portability and lightweight design. Furthermore, an excessively large focal length ratio may cause a shift in the position of the imaging plane, making it difficult for the observer to accurately capture the target image, thus affecting the observation effect and accuracy of the eyepiece. In addition, a large focal length ratio also increases aberrations.

[0074] Therefore, focal length ratios (F1+F2) / f less than 4.4 or greater than 4.6 can lead to various problems, including decreased image quality, reduced observer eye comfort, insufficient light convergence, excessively long focal length, and image plane position shift. Thus, in the lens module provided in this application embodiment, a new focal length ratio design has been specifically implemented for the eyepiece, and controlling the focal length ratio range of 4.4 ≤ (F1+F2) / f ≤ 4.6 is crucial.

[0075] In some examples of this application, the second lens group satisfies: 3.1≤|(f2+f4) / f3|≤3.3; where 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 |(f2+f4) / f3| within the range of 3.1 to 3.3, the focal lengths of the three lenses included in the second lens group are reasonably adjusted in this example of the application. This design aims to optimize the imaging performance of the second lens group and ensure that light can form good image quality after passing through the lens group.

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

[0078] The ratio in this example includes an absolute value sign; regardless of whether (f2+f4) and f3 have the same sign, the ratio must satisfy a given range. This reflects that when considering focal length relationships, not only the numerical magnitude is taken into account, but also the influence of the sign of optical power on imaging.

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

[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 cause light to be insufficiently refracted and focused when passing through the second lens group, thus affecting image quality. For example, this manifests as reduced image sharpness and increased aberrations.

[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 and fourth lenses is too large relative to the focal length of the third lens. This will lead to overcorrection of aberrations, thereby introducing new aberration problems. An unreasonable focal length ratio will also result in uneven spatial distribution within the eyepiece. To meet imaging requirements, it may be necessary to increase the number or thickness of lenses, leading to an increase in the overall size and weight of the eyepiece, and consequently, a larger and heavier lens module. This not only hinders the portability and lightweight design of optical lenses but may also increase manufacturing costs.

[0082] Therefore, the focal length ratio of 3.1 ≤ |(f2+f4) / f3| ≤ 3.3 is crucial for the imaging quality and performance of short-focal-length high-definition observation and aiming 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 decreased image quality, unstable eyepiece performance, overcorrection of aberrations, and increased eyepiece size.

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

[0084] In some examples of this application, the third lens group satisfies: 1.6≤|f5 / f6|≤1.9; where 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 cemented doublet lens group, see [link / reference]. Figure 1 The lens comprises a fifth lens 5 and a sixth lens 6. When the fifth lens 5 has a positive optical power and the sixth lens 6 has a negative optical power, their combination effectively eliminates aberrations, resulting in a clearer image. The cemented doublet lens allows for better control of the light propagation path, enabling more light to pass through the eyepiece and be captured by the imaging surface. This helps improve the light utilization rate of the eyepiece, further enhancing image quality. Furthermore, the design of controlling the focal length ratio of the fifth lens 5 and the sixth lens 6, |f5 / f6|, between 1.6 and 1.9 helps ensure the performance stability of the eyepiece under different environmental conditions. When the fifth lens 5 and the sixth lens 6 are cemented together, their optical performance is more stable and less susceptible to the influence of external factors such as temperature and humidity. Simultaneously, a reasonable focal length ratio further reduces the impact of environmental factors on the lens's imaging performance, ensuring consistent imaging results under various conditions.

[0086] While ensuring high-quality imaging, by reasonably controlling the focal length ratio of the two lenses in the third lens group, the overall size of the eyepiece and the image quality can be balanced to a certain extent. The focal length ratio range in this example implies a more compact relative position between the fifth lens 5 and the sixth lens 6, which helps to reduce the overall size of the eyepiece and improve its portability and lightweight design. This enables the miniaturization of the entire lens module.

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

[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 light to be insufficiently refracted and focused when passing through the third lens group, thus affecting image quality. For example, this may manifest as reduced image sharpness, increased aberrations, and potential image distortion or distortion.

[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 overcorrection of aberrations, thereby introducing new aberration problems. Furthermore, an unreasonable focal length ratio may result in uneven spatial distribution within the eyepiece. To meet imaging requirements and maintain a reasonable focal length ratio, it may be necessary to increase the number or thickness of the lenses, leading to an increase in eyepiece size. This not only hinders the portability and lightweight design of the eyepiece but may also increase its manufacturing cost.

[0090] Therefore, the focal length ratio range of 1.6 ≤ |f5 / f6| ≤ 1.9 is crucial for the imaging quality and overall performance of short-focal-length, high-resolution eyepieces. When the value of |f5 / f6| is less than 1.6 or greater than 1.9, it may lead to a number of problems, such as decreased image quality, unstable lens module performance, increased design complexity, overcorrection of aberrations, and increased lens module size. Therefore, this focal length ratio range should be carefully controlled during the design and manufacturing process of the eyepiece to ensure that the resulting eyepiece or lens module containing it has excellent imaging quality and stable performance.

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

[0092] Both the second and third lens groups contain lenses with negative optical power. Setting the focal length ratio between F3 and F2 appropriately 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 application, 1.2 ≤ |F3 / F2| ≤ 1.8, offers broader 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] While ensuring high-quality imaging, the size and weight of the eyepiece can be reduced to a certain extent by reasonably controlling the focal length ratio of the second and third lens groups and introducing negative power lenses.

[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 compared to the second lens group. This will cause light to not converge or diverge sufficiently when passing through the third lens group, thus affecting image quality. Specifically, this may manifest as blurred images, increased aberrations, and other problems. The shorter focal length of the third lens group may also result in a smaller field of view for the eyepiece, limiting its shooting range. Furthermore, to achieve high-quality imaging with a smaller focal length ratio, it may be necessary to increase the number or thickness of the lenses, leading to an increase in the size 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. This will cause greater aberrations when light passes through the third lens group, thus affecting the sharpness of the image.

[0097] Therefore, in this example of the application, the design of 1.2 ≤ |F3 / F2| ≤ 1.8 is based on a comprehensive consideration of the eyepiece's performance and imaging quality. Exceeding this range may lead to problems such as decreased imaging quality, limited field of view, increased difficulty in lens design, increased lens size and weight, and increased aberrations.

[0098] In this example of the application, the design of 1.2 ≤ |F3 / F2| ≤ 1.8, combined with the introduction of negative power lenses in the second and third lens groups, constitutes an important feature of the short-focal-length, high-definition observation and aiming lens. These designs contribute to optimizing image quality, enhancing eyepiece adaptability, improving eyepiece design flexibility, reducing eyepiece size and weight, and increasing eyepiece stability. These effects collectively enable the resulting eyepiece to meet the needs of various complex application scenarios and provide users with a superior imaging experience.

[0099] See some examples in this application. Figure 1The optical effective aperture D of the largest lens in the eyepiece max The relationship between the image height h of the eyepiece and the given image height h satisfies: 3.6 ≤ D max / h≤4.3.

[0100] By controlling D max A ratio between 3.6 and 4.3 for h ensures that the light projected onto the eyepiece forms a clear and sharp image after passing through each lens group.

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

[0102] Within this scale range of the example in this application, the eyepiece can effectively utilize light, reducing light loss and aberrations. Light is refracted and focused as it passes through the lens group in the eyepiece, and a reasonable D... max The ratio of h ensures that light is focused in the best way, thus forming a high-quality image.

[0103] In other words, by controlling the optically effective aperture D of the largest lens in the eyepiece max A ratio between 3.6 and 4.3 between the image height (h) and the eyepiece's image height (h) enables high-resolution imaging, optimized light utilization, a short focal length design, a wide field of view, and good manufacturability and reliability. These effects collectively enhance the overall performance and application value of the eyepiece.

[0104] When D max A value of / h less than 3.6 can lead to a decrease in image sharpness. This is because a smaller D... max This could mean that the lens has a limited ability to collect light, resulting in uneven light distribution or insufficient light on the focal plane. This can cause blurring at the edges of the image, reducing overall image sharpness. Due to the small aperture of the lens, more light may be lost as it passes through it, especially when light enters the lens at an angle. This reduces light utilization efficiency and affects the brightness and contrast of the image.

[0105] To maintain a certain image quality, when D max When the light collection capacity is small, the focal length of the lens needs to be increased to compensate for the insufficient light collection capacity. This will result in a larger overall size of the eyepiece, which in turn will affect the size of the entire lens module.

[0106] When D maxA value greater than 4.3 can lead to increased aberrations, which reduces image sharpness and resolution, affecting the viewing experience. Larger lens apertures require more precise machining and assembly processes, increasing manufacturing costs; simultaneously, larger lenses also mean more material is needed, further increasing costs. Furthermore, larger lens apertures and focal lengths may increase the overall weight of the lens module.

[0107] Therefore, when D max A ratio of / h less than 3.6 or greater than 4.3 may adversely affect the imaging quality, light utilization, and focal length design of the eyepiece and even the lens module in this application. Therefore, when designing the eyepiece, multiple factors need to be considered comprehensively to ensure the overall performance of the lens module containing the eyepiece. The ratio range in this example is a relatively reasonable choice, which can ensure imaging quality while taking into account factors such as the size, weight, and cost of the lens module.

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

[0109] See 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 towards the center, providing a basis for the subsequent imaging process. By coordinating the optical power distribution of the first lens group (positive optical power) with that of the second and third lens groups, the overall optical power of the eyepiece can be balanced, thereby ensuring high-quality imaging.

[0110] The first lens 1, with positive optical power, enhances the converging ability of light, allowing light to be more accurately focused onto the image plane after passing through the lens. This is crucial for improving the image sharpness and resolution of the eyepiece.

[0111] The eyepiece design in this application primarily achieves a short focal length and high resolution based on the allocation of optical power. The positive optical power design of the first lens 1 is an integral part of this scheme. Through the rational allocation and synergistic effect of optical power with other lens groups, high-resolution imaging performance can be maintained at a relatively short focal length. This not only improves the shooting effect of the eyepiece but also reduces its size and weight, enhancing its portability and practicality.

[0112] The positive optical power design of the first lens 1 plays a crucial role in short-focal-length, high-definition viewing lenses. By coordinating with the optical power distribution of the second and third lens groups, it achieves a balance in the overall eyepiece optical power and optimizes light convergence; simultaneously, it expands the field of view, controls aberrations, and improves eyepiece stability. These effects collectively achieve the technical goals of short focal length and high definition, providing technical support for the design and application of lens modules.

[0113] In some examples of this 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] Optical power is a physical quantity that describes the ability of a lens or lens group to refract light; its positive or negative value represents the converging or diverging effect of the lens or lens group on light. In this example of the application, the optical power of the first lens group is positive, the optical power of the second lens group is also positive, while the optical power of the third lens group is negative. This configuration achieves a short focal length design for the eyepiece.

[0115] Specifically, both the first and second lens groups are configured with positive optical power, which helps to converge light and shorten the overall length of the eyepiece. Positive optical power lens groups can effectively converge light from the observed object to the center of the lens, providing a good foundation for subsequent imaging. The third lens group is configured with negative optical power, which helps to diverge light, further shortening the lens's focal length and adjusting the light path to meet specific imaging requirements.

[0116] This example of the application optimizes aberration correction by appropriately combining lens groups with positive and negative optical powers. This configuration helps reduce light loss and distortion during refraction and reflection within the eyepiece, thereby improving image sharpness and accuracy.

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

[0118] In the eyepiece provided in this application, the first lens 1, located on the exit pupil side, is a biconvex lens to enhance light converging ability. Specifically, both sides of the biconvex lens are convex surfaces, causing light to be more strongly refracted when passing through the lens, thereby enhancing the light converging ability. This helps to achieve a clearer imaging effect at short focal lengths.

[0119] As the first lens on the exit pupil side, the power distribution of the first lens 1 has a significant impact on the overall performance of the eyepiece. The design of the biconvex lens allows the first lens 1 to have a more suitable positive power, providing a good foundation for the focal length distribution and imaging performance of subsequent lens groups.

[0120] In some examples of this 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 in this application includes a second lens group located between the first and third lens groups. This second lens group comprises three lenses cemented together. The second lens 2 is close to the first lens 1 and is a biconvex lens, further enhancing the light-convexity. Working in conjunction with the first lens, the eyepiece maintains high image sharpness at short focal lengths, helping to control aberrations and improve the image 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-convexity capability, enabling the eyepiece to capture more light information at a short focal length, thereby improving the brightness and clarity of the image. Simultaneously, this also helps to expand the eyepiece's field of view.

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

[0125] The eyepiece provided in this application also includes a third lens group, which comprises a fifth lens 5 and a sixth lens 6 cemented together. The fifth lens 5 and the sixth lens 6 are designed as convex and concave lenses, which allows the eyepiece to maintain a shorter focal length while possessing better focal length adjustment and aberration control capabilities. By adjusting the curvature and thickness of the convex and concave lenses, the imaging performance of the eyepiece can be further optimized. Furthermore, the convex and concave lens design helps enhance the structural stability of the eyepiece, enabling it to maintain stable imaging performance in complex lighting environments.

[0126] The eyepiece provided in this application is shown in [reference]. Figure 1 It includes at least 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. By reasonably combining and matching these six lenses, the following combined effect can be produced:

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

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

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

[0130] (4) Improve lens stability and durability: The proper matching and combination of lenses can enhance the structural stability of the lens and improve its durability and lifespan.

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

[0132] Spherical lenses offer stable imaging performance. Furthermore, their manufacturing process is relatively simple, efficient, and low-cost, making them suitable for mass production. Glass materials possess excellent light transmission and refractive index stability, enabling 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. Furthermore, the first lens 1 to the sixth lens 6 may all be aspherical lenses.

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

[0135] In the lens module provided in this application embodiment, the objective lens system 7 is located on the side of the eyepiece away from the exit pupil, and is able to receive light from the observed object. By reasonably designing the parameters of the objective lens system 7 (such as focal length, aperture, etc.), the light collection capability of the lens module can be significantly enhanced, thereby improving the light transmission and brightness of the lens module.

[0136] The introduction of the objective lens system 7 further enhances the optical performance of the lens module. The objective lens system 7 can perform preliminary adjustments and optimizations to the light, reducing light loss and distortion during propagation, thereby improving the overall image quality and sharpness of the lens module. The effect of the objective lens system 7 is particularly pronounced in long-distance observation or low-light environments.

[0137] With the introduction of the objective lens system 7, the application areas of the lens module can be further expanded.

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

[0139] When the objective lens system 7 receives 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. With the addition of 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 this application, the display screen 8 displays reticle markings; the objective lens system 7 includes an imaging device electrically connected to the display screen 8, and the target image captured by the imaging device can be displayed on the display screen 8.

[0141] The reticle markings displayed on the screen 8 provide the user with an intuitive reference frame. Users can use these reticles to more accurately locate the observation target, especially in scenarios requiring precise measurement or aiming; this design significantly improves the accuracy and precision of observations.

[0142] The electrical connection between the shooting device and the display screen 8 allows the target image captured by the shooting device to be displayed on the display screen 8 in real time. This real-time image display function facilitates immediate observation and judgment by the user.

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

[0144] In some examples of this application, when the light received by the objective lens system is visible light, the objective lens system 7 is located on the 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 is focused and forms a clear image on a plane, which is the image plane of the objective lens system 7. Because there is a gap between the objective lens system 7 and the third lens group of the eyepiece, this gap provides the necessary space for the formation of the image plane.

[0146] According to this example of the application, the spacing allows light to diffuse and focus sufficiently after passing through the objective lens system 7, thereby forming a clearer and sharper image plane. The sharpness and position of the image plane are crucial for subsequent imaging processes, as they directly affect the image quality seen by the observer through the eyepiece; the spacing also helps reduce optical interference between the objective lens system 7 and the third lens group, which could degrade image quality, and the spacing helps mitigate these adverse effects.

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

[0148] The eyepiece in this application is further described below through Examples 1 and 2.

[0149] Example 1

[0150] The eyepiece provided in this embodiment 1 is described in [reference]. Figure 1 It includes a first mirror group, a second mirror group, and a third mirror group arranged sequentially along the same optical axis on the exit pupil side;

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

[0152] The second lens group includes a second lens 2, a third lens 3, and a fourth lens 4 cemented 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.

[0153] The third lens group includes a fifth lens 5 and a sixth lens 6 bonded together, wherein the fifth lens 5 has positive optical power and the sixth lens 6 has negative optical 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 of the first lens group is F1, which is 45.5mm; the focal length of the second lens group is F2, which is 58.1mm; and the focal length of the third lens group is F3, which is -100.2mm.

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

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

[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, as follows.

[0161] Table 1

[0162]

[0163] Example 2

[0164] The eyepiece provided in this embodiment 2 has the same optical structure as that in embodiment 1 described above, as can be found in [reference needed]. Figure 1 The difference lies in:

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

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

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

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

[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, as follows.

[0171] Table 2

[0172]

[0173]

[0174] The eyepieces provided in Examples 1 and 2 have the following optical performance: Figures 2 to 5 As shown: Figure 2 This is a schematic diagram of a dot-matrix diagram. Figure 3 It is an MTF curve. Figure 4 It is a field curvature and distortion diagram. Figure 5 It is a vertical axis color difference diagram.

[0175] See Figure 2 The maximum value of the image point in the dot matrix diagram provided by the eyepieces in Examples 1 and 2 is less than 6μm.

[0176] See Figure 3 The eyepieces provided in Examples 1 and 2 have an MTF > 0.3 at 80 lp / mm.

[0177] See Figure 4 The eyepieces provided in Examples 1 and 2 exhibit the largest distortion occurring in the field of view, with an absolute value of less than 13%, indicating very small distortion.

[0178] See Figure 5 The eyepieces provided in Examples 1 and 2 have a maximum chromatic difference value of less than 6 μm.

[0179] The above embodiments mainly describe 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. For the sake of brevity, they will not be elaborated here.

[0180] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A lens module, characterized in that, The lens module includes an eyepiece; The eyepiece includes a first lens group, a second lens group, and a third lens group arranged sequentially 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) cemented 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 includes a fifth lens (5) and a sixth lens (6) bonded together, wherein the fifth lens (5) has positive optical power and the sixth lens (6) has negative optical power; The eyepiece satisfies: 4.4 ≤ ( F 1+ F 2) / f ≤4.6; where, F 1 represents the focal length of the first lens group. F 2 is the focal length of the second lens group. f The total focal length of the eyepiece is denoted as .

2. The lens module according to claim 1, characterized in that, The second mirror group satisfies: 3.1 ≤ |( f 2+ f 4) / f 3|≤3.3; where, f 2 is the focal length of the second lens (2). f 3 is the focal length of the third lens (3). f 4 is the focal length of the fourth lens (4).

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

4. The lens module according to claim 1, characterized in that, The eyepiece satisfies: 1.2 ≤ | F 3 / F 2|≤1.8; in, F 2 is the focal length of the second lens group. F 3 represents the focal length of the third lens group.

5. The lens module according to claim 1, characterized in that, The optical effective aperture D of the largest lens in the eyepiece max Image height with the eyepiece h The condition is satisfied that: 3.6 ≤ D max / h ≤4.

3.

6. The lens module according to any one of claims 1-5, characterized in that, The first lens (1) has positive optical power.

7. The lens module according to claim 6, 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.

8. The lens module according to claim 6, characterized in that, The first lens (1) is a biconvex lens.

9. The lens module according to claim 8, 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.

10. The lens module according to claim 9, characterized in that, The fifth lens (5) and the sixth lens (6) are convex and concave lenses.

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

12. The lens module according to claim 11, characterized in that, When the light received by the objective lens system (7) is infrared light, the lens module also includes a display screen (8), which is located between the third lens group and the objective lens system (7).

13. The lens module according to claim 12, characterized in that, The display screen (8) displays the dividing line markings; The objective lens system (11) includes an imaging device that is electrically connected to the display screen (8), and the target image captured by the imaging device can be displayed on the display screen (8).

14. The lens module according to claim 11, characterized in that, When the light received by the objective lens system is visible light, the objective lens system (7) is located on the 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.

15. An optical lens, characterized in that, include: shell; and The lens module as described in any one of claims 1-14.

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