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 and a second lens group which are arranged along the same optical axis of an exit pupil side; the first lens group comprises a first lens and a second lens, and the first lens group has positive focal power; the second lens group comprises a third lens and a fourth lens, and the second lens group has negative focal power; the eyepiece comprises a light splitting element, a phase retarder and a polarization reflection element, the light splitting element is arranged on the side, close to the exit pupil side, of the fourth lens, the polarization reflection element is arranged on the side, close to the exit pupil side, of the first lens, and the phase retarder is located between the light splitting element and the polarization reflection element.

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] As an important component of optical instruments such as telescopes and microscopes, the performance of eyepieces directly affects the visual experience and observation effect of the observer. Traditional eyepiece designs often fail to meet multiple requirements such as miniaturization, lightness, and high imaging quality while meeting basic imaging requirements. In particular, with the continuous advancement of modern optical technology, higher requirements are placed on the resolution, exit pupil diameter, and exit pupil distance of eyepieces. 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 includes a first lens group and a second lens group arranged along the same optical axis on the exit pupil side;

[0006] The first lens group includes a first lens and a second lens, and the first lens group has positive optical power;

[0007] The second lens group includes a third lens and a fourth lens, and the second lens group has negative optical power;

[0008] The eyepiece also includes a beam splitter, a phase delay and a polarization reflection element. The beam splitter is arranged on a side of the fourth lens close to the exit pupil, the polarization reflection element is arranged on a side of the first lens close to the exit pupil, and the phase delay is located between the beam splitter and the polarization reflection element.

[0009] Optionally, the eyepiece satisfies: 6.5mm≤F1+F2+f≤7.1mm; 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 eyepiece satisfies: 0.6<(EP×ED) / (f×h)<2.03; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

[0011] Optionally, the eyepiece satisfies: 0.6<EP / (NA×h)<2.03; wherein NA is the aperture of the eyepiece.

[0012] Optionally, the first lens group satisfies:

[0013] 4.74≤(f1+f2) / F1≤5;

[0014] Among them, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and F1 is the focal length of the first lens group.

[0015] Optionally, both the first lens and the second lens have positive optical power.

[0016] Optionally, the second lens group satisfies:

[0017] 4.34≤(f3+f4) / F2≤4.38;

[0018] Among them, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and F2 is the focal length of the second lens group.

[0019] Optionally, the third lens and the fourth lens both have negative optical power.

[0020] Optionally, the first mirror group satisfies: 2.29≤f1 / f2≤2.59, and the second mirror group satisfies: 1.75≤f4 / f3≤1.81.

[0021] Optionally, the eyepiece satisfies:

[0022] 4.35≤|(F1+F2) / TG|≤4.52;

[0023] Wherein, TG is the distance between the first mirror group and the second mirror group.

[0024] Optionally, the polarized reflection element and the phase retarder are stacked and arranged on a surface of the first lens close to the exit pupil side;

[0025] The beam splitter is disposed on a surface of the fourth lens close to the exit pupil side.

[0026] Optionally, a polarizing element is provided on a surface of the fourth lens away from the exit pupil side.

[0027] Optionally, the first lens is a plano-convex spherical mirror, the second lens is a convex-concave aspherical mirror, the third lens is a concave-convex spherical mirror, and the fourth lens is a plano-convex spherical mirror.

[0028] Optionally, the exit pupil distance EP of the eyepiece is 15 mm to 25 mm, the exit pupil diameter ED of the eyepiece is 25 mm to 35 mm, the aperture NA of the eyepiece is 1.337 to 1.872, the image height h of the eyepiece is 9.2 mm to 13 mm, and the FOV of the eyepiece is 11.2° to 15.9°.

[0029] 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.

[0030] 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 second lens group and the objective lens system.

[0031] Optionally, a reticle mark is displayed on the display screen;

[0032] 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.

[0033] Optionally, when the light received by the objective lens system is visible light, the objective lens system is located on a side of the second lens group away from the exit pupil side, and the objective lens system and the second lens group are spaced apart.

[0034] In a second aspect, the present application provides an optical lens, wherein the optical lens comprises:

[0035] casing; and

[0036] A lens module as described in the first aspect.

[0037] The beneficial effects of this application are:

[0038] The lens module provided in the embodiment of the present application is a high-definition sighting lens module with a large exit pupil. By combining a first lens group with positive focal length and a second lens group with negative focal length, and introducing optical film materials such as a spectroscopic element, a phase retarder, and a polarized reflective element in the module, excellent optical imaging performance is achieved, which is beneficial to improving imaging quality and clarity. In the lens module provided in the present application, the large exit pupil design of the eyepiece not only improves the user's comfort, but also expands the scope of application of the eyepiece. In addition, the present application realizes a miniaturized and lightweight design of the eyepiece. The above advantages make the lens module of the present application have a wide range of application prospects in optical instruments such as telescopes and microscopes, and have high practical value and market potential.

[0039] 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

[0040] 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.

[0041] Figure 1A schematic diagram of the structure of the lens module provided in an embodiment of the present application;

[0042] Figure 2 A dot array diagram of the eyepiece in the lens module provided in an embodiment of the present application;

[0043] Figure 3 The MTF diagram of the eyepiece in the lens module provided in the embodiment of the present application;

[0044] Figure 4 A diagram showing the distortion and field curvature of the eyepiece in the lens module provided in an embodiment of the present application;

[0045] Figure 5 This is a vertical axis chromatic aberration diagram of the eyepiece in the lens module provided in an embodiment of the present application.

[0046] Description of reference numerals:

[0047] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Polarization reflection element; 6. Phase retarder; 7. Beam splitter; 8. Polarization element; 9. Objective lens system; 10. Display screen. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] According to an embodiment of the present application, a lens module is provided. Figure 1The lens module includes an eyepiece, and the eyepiece includes a first lens group and a second lens group arranged along the same optical axis on the exit pupil side; the first lens group includes a first lens 1 and a second lens 2, and the first lens group has positive focal length; the second lens group includes a third lens 3 and a fourth lens 4, and the second lens group has negative focal length; the eyepiece also includes a beam splitter 7, a phase retarder 6 and a polarization reflection element 5, the beam splitter 7 is arranged on a side of the fourth lens 4 close to the exit pupil side, the polarization reflection element 5 is arranged on a side of the first lens 1 close to the exit pupil side, and the phase retarder 6 is located between the beam splitter 7 and the polarization reflection element 5.

[0055] The lens module proposed in the embodiment of the present application is a high-definition sighting lens module that can take into account a large exit pupil and has a wide range of applications. The following is a detailed description of its application range.

[0056] The lens module of the embodiment of the present application can be applied to a telephoto lens, especially a telephoto lens that requires high-definition observation and a wide exit pupil to meet the needs of long-term comfortable observation. The lens module of the present application can provide an excellent visual observation experience.

[0057] In sports such as shooting and archery, the accuracy and clarity of the aiming lens are crucial. The lens module provided in this application can be a choice for aiming lenses based on the high definition and precise optical design of the eyepiece therein. At the same time, its large exit pupil design can also make the shooter more comfortable when aiming and reduce eye fatigue.

[0058] The lens module of the present application is also applicable to photographic and video equipment that require high resolution and clear imaging. It can be used as a supplement to a macro lens, a telephoto lens or a wide-angle lens to help capture more delicate and clear images.

[0059] The lens module provided in the embodiment of the present application is shown in FIG. Figure 1 , which includes two major parts, an eyepiece and an objective lens. The eyepiece is described first. Specifically, the eyepiece of the present application includes two lens groups: a first lens group and a second lens group, and the two lens groups are arranged 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 is located on the side of the first lens group away from the exit pupil side, that is, the side close to the observed object or the imaging surface. This design ensures the effective transmission and focusing of light from the object side to the image side.

[0060] Please continue to see Figure 1The first lens group includes a first lens 1 and a second lens 2, and the first lens group has positive focal length, which can be used to converge light. The second lens group includes a third lens 3 and a fourth lens 4, and the second lens group has negative focal length, which can be used to correct aberrations and adjust focal length. This combination design of positive and negative focal lengths in the optical path helps to achieve high-quality imaging effects.

[0061] For the eyepiece provided in the embodiment of the present application, the first lens group has positive focal power, while the second lens group has negative focal power. The combination of positive focal power and negative focal power helps to correct chromatic aberration. Light of different wavelengths has different refractive indexes when passing through the lens, which will cause the image position to shift, i.e., chromatic aberration. Through the reasonable combination of positive and negative focal power, light of different wavelengths can be more accurately converged to the same point after passing through the eyepiece, thereby reducing or eliminating chromatic aberration and improving image quality.

[0062] Distortion is a common problem in optical systems, which causes the image to distort. The combination of positive and negative optical power can effectively control distortion by refraction and convergence of light, making the image more realistic and accurate.

[0063] In addition, by properly matching positive and negative focal powers, the number and complexity of lenses can be reduced while ensuring the optical performance of the eyepiece, which helps to reduce the size and weight of the eyepiece and improve its portability and comfort.

[0064] In the eyepiece provided in this application, see Figure 1 The polarized reflection element 5 is arranged on the side of the first lens 1 away from the second lens 2. The polarized reflection element 5 has a polarization property and can reflect or transmit light in a specific direction, thereby achieving control of the light path.

[0065] The beam splitter element 7 is disposed on a side of the fourth lens 4 close to the third lens 3 . The beam splitter element 7 is, for example, a semi-transparent and semi-reflective film, which can transmit and reflect light at the same time.

[0066] The phase retarder 6 is disposed between the polarized reflective element 5 and the beam splitter 7. The phase retarder 6 can change the phase of the light, further realizing the control of the light path. The phase retarder 6 is a quarter wave plate.

[0067] It should be noted that the phase retarder 6 should be located between the beam splitter element 7 and the polarized reflection element 5 .

[0068] In the present application, a folded optical path design is achieved by arranging a polarized reflection element 5 on the side of the first lens 1 away from the second lens 2, and arranging a beam splitter 7 (semi-transparent and semi-reflective film) on the side of the fourth lens 4 close to the third lens 3, and combining a phase retarder 6 (quarter wave plate) arranged between the two. This design not only makes the structure of the eyepiece more compact, but also reduces the length of the optical path, helps to reduce light loss, and improves imaging quality.

[0069] The eyepiece solution provided in the present application divides the eyepiece into a first lens group and a second lens group and adopts a folded optical path design, so that the structure of the entire eyepiece is more compact. This compact structural design not only reduces the volume and weight of the eyepiece, but also improves its portability, so that the eyepiece can be more widely used in various handheld or portable observation and aiming devices.

[0070] It should be noted that the eyepiece provided in the present application, wherein the first lens group includes but is not limited to 2 lenses, and lenses can be appropriately increased as needed. Of course, the second lens group also includes but is not limited to 2 lenses, and the number of lenses can be flexibly adjusted as needed.

[0071] The lens module provided in the embodiment of the present application is a high-definition sighting lens module with a large exit pupil. By combining a first lens group with positive focal length and a second lens group with negative focal length, and introducing optical film materials such as a beam splitter 7, a phase retarder 6 and a polarized reflective element 5 in the module, excellent optical imaging performance is achieved, which is beneficial to improving imaging quality and clarity. In the lens module provided in the present application, the large exit pupil design of the eyepiece not only improves the user's comfort, but also expands the scope of application of the eyepiece. In addition, the present application realizes a miniaturized and lightweight design of the eyepiece. The above advantages make the lens module of the present application have a wide range of application prospects in optical instruments such as telescopes and microscopes, and have high practical value and market potential.

[0072] In some examples of the present application, the eyepiece satisfies: 6.5mm≤F1+F2+f≤7.1mm; 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.

[0073] The eyepiece provided in this example of the present application satisfies a specific focal length relationship, 6.5mm≤F1+F2+f≤7.1mm; 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. The setting of this focal length relationship in the present application is intended to optimize the optical performance of the eyepiece and ensure high definition imaging and a large exit pupil effect.

[0074] If the sum of the focal lengths F1+F2+f is less than 6.5mm, the image clarity will decrease. Specifically, a focal length that is too short may cause the light to not fully converge when passing through the eyepiece, thus forming a blurred image on the retina, affecting the observer's visual experience.

[0075] If the sum of focal lengths F1+F2+f is less than 6.5mm, the field of view of the entire eyepiece may be reduced, limiting the application range of the eyepiece. In addition, if the sum of focal lengths is too short, it may increase the distortion and chromatic aberration of the eyepiece, especially in the edge area, where these problems may be more obvious and affect the image quality.

[0076] If the sum of the focal lengths F1+F2+f is greater than 7.1 mm, this indicates that the focal length of the eyepiece may be too long, and a too long focal length usually means that the eyepiece requires more lens groups and a more complex structural design, which may increase the volume and weight of the eyepiece, thereby increasing the volume and weight of the entire lens module. In addition, a too long focal length may cause the exit pupil diameter to decrease, which will affect the observer's visual effect in a dark environment and reduce the comfort and accuracy of observation.

[0077] In this example of the present application, the eyepiece satisfies a specific focal length relationship: 6.5mm≤F1+F2+f≤7.1mm. This focal length range is set to balance multiple optical performance parameters, including image clarity and exit pupil effect. Through focal length matching and lens design, it can be ensured that light can be converged in the best way when passing through the eyepiece to form a high-quality image while ensuring a large exit pupil diameter.

[0078] Based on the special design of the eyepiece, the eyepiece in this example of the present application can maintain high resolution and clarity while also having excellent performances such as large exit pupil and high contrast. In particular, the large exit pupil design improves the user's comfort and adaptability, and the high contrast design helps reduce glare and reflections, and improves the three-dimensional sense and realism of the image.

[0079] In some examples of the present application, the eyepiece satisfies: 0.6<(EP×ED) / (f×h)<2.03; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

[0080] By controlling the proportional relationship between the eyepiece's exit pupil distance (EP) and exit pupil diameter (ED) and the eyepiece's total focal length (f) and image height (h), this example of the present application can ensure that the eyepiece can provide a larger and clearer field of view. It should be noted that the eyepiece involved in this application is mainly for sighting applications. Compared with optical devices such as virtual reality (VR), its field of view (FOV) is relatively small, but the "larger field of view" emphasized here is relative to similar sighting lenses, reflecting a significant advantage in specific application fields. For example, the field of view of the eyepiece of the present application is 11° to 16°.

[0081] A larger exit pupil distance (EP) allows the observer to observe the eyepiece comfortably at a greater distance, reducing eye fatigue. A larger exit pupil diameter (ED) allows more light to enter the eyepiece, improving the brightness and contrast of the image, especially in low-light environments. By controlling the above proportional relationship, the image quality of the eyepiece can be optimized. The impact of a small change in image height (h) on image quality is limited to a certain range, thereby improving the accuracy and stability of observation.

[0082] The proportional relationship in this example of the present application enables the eyepiece to adapt to different observation conditions and observer needs, and to maintain a clear imaging effect whether it is close-up observation or long-distance observation.

[0083] When the value of (EP×ED) / (f×h) is less than 0.6, it means that the exit pupil diameter (ED) and / or exit pupil distance (EP) of the eyepiece are small relative to the total focal length (f) and image height (h) of the eyepiece. This may result in a limited field of view for the observer and an inability to obtain a sufficient observation range. A smaller exit pupil diameter (ED) reduces the amount of light entering the eyepiece, which affects the brightness and contrast of the image. In low-light environments, this may cause the image to become blurred or difficult to recognize. A smaller exit pupil distance (EP) may also require the observer to put his eyes close to the eyepiece, which can increase eye fatigue and discomfort. Due to the limited field of view and reduced image clarity, the observer's observation accuracy may be affected, especially in scenes that require precise identification.

[0084] When the value of (EP×ED) / (f×h) is greater than 2.03, it means that the exit pupil diameter (ED) and / or the exit pupil distance (EP) of the eyepiece are too large relative to the total focal length (f) and image height (h) of the eyepiece. This may cause the eyepiece to introduce more aberrations, thereby affecting the clarity of the image. In order to meet the larger exit pupil diameter (ED) and exit pupil distance (EP), the design and manufacture of the eyepiece will become more complicated, which will undoubtedly increase the manufacturing cost and difficulty, and may also reduce the reliability of the entire lens module.

[0085] It can be seen that a ratio of (EP×ED) / (f×h) less than 0.6 or greater than 2.03 may cause a series of problems, including limited field of view, reduced image clarity, reduced observer comfort, limited observation accuracy, increased aberrations, increased system complexity, limited observation range, and unnecessary weight and volume. Therefore, when designing high-definition large exit pupil observation eyepieces, this ratio needs to be precisely controlled to ensure the optimal performance of the eyepiece.

[0086] In some examples of the present application, the eyepiece satisfies: 0.6<EP / (NA×h)<2.03; wherein NA is the aperture of the eyepiece.

[0087] In this example of the present application, by controlling the proportional relationship between the exit pupil distance EP of the eyepiece and its aperture NA and image height h, the exit pupil distance can be optimized while ensuring sufficient light input, so that the observer can observe the eyepiece at a more comfortable distance.

[0088] A larger pupil distance helps reduce the observer's eye fatigue and improves observation comfort.

[0089] The size of the aperture NA directly affects the amount of light entering the eyepiece. Under the proportional relationship provided in this example of the present application, by reasonably setting the aperture size, it is possible to ensure that the eyepiece provided by the present application obtains sufficient light intake, thereby improving the brightness and contrast of the image. This is particularly important in low-light environments and can significantly improve the visibility and recognition of the image.

[0090] The change of image height h has a certain influence on the imaging quality. By accurately controlling the proportional relationship between EP and NA×h, the influence of image height change on imaging quality can be reduced, thereby improving the accuracy and stability of observation.

[0091] When the value of EP / (NA×h) is less than 0.6, it means that the exit pupil distance EP is too small relative to the given aperture NA and image height h. This may cause the observer to put his eyes very close to the eyepiece when using the eyepiece, resulting in a narrow field of view, while increasing eye fatigue and discomfort. A smaller exit pupil distance EP may limit the angle and range of light entering the eyepiece, resulting in insufficient light utilization. This will affect the brightness and contrast of the image, especially in low-light environments, which may cause the image to become dim or difficult to observe. Due to the narrow field of view and insufficient light utilization, the observer's observation accuracy may be affected.

[0092] When the value of EP / (NA×h) is greater than 2.03, it means that the exit pupil distance EP is too large relative to the given aperture NA and image height h. This may cause the eyepiece to introduce more aberrations, thereby affecting the clarity and quality of the image. In addition, in order to meet the larger exit pupil distance EP, the design and manufacture of the eyepiece may require a more complex structure and more materials. In addition, a larger exit pupil distance EP may increase the overall size of the eyepiece, thereby limiting the observer's head movement range and observation angle.

[0093] It can be seen that a ratio of EP / (NA×h) less than 0.6 or greater than 2.03 may cause a series of problems, including narrow field of view, insufficient light utilization, limited observation accuracy, increased aberrations, increased structural complexity, and limited observation range. Therefore, when designing high-definition large-exit-pupil observation eyepieces, it is necessary to accurately control this ratio to ensure that the performance of the eyepiece is optimal.

[0094] In some examples of the present application, the first lens group satisfies: 4.74≤(f1+f2) / F1≤5; wherein f1 is the focal length of the first lens 1 , and f2 is the focal length of the second lens 2 .

[0095] In this example of the present application, the focal length relationship satisfied by the first lens group in the eyepiece is: 4.74≤(f1+f2) / F1≤5. This ratio reflects the relationship between the sum of the focal lengths of the first lens 1 and the second lens 2 and the overall focal length of the first lens group.

[0096] f1: the focal length of the first lens 1, which determines the ability of the first lens 1 to converge or diverge light.

[0097] F2: The focal length of the second lens 2, which also affects the convergence or divergence of light.

[0098] F1: The focal length of the first lens group is the overall focal length of the first lens 1 and the second lens 2 combined, reflecting the overall effect of the first lens group on light.

[0099] According to this example of the present application, by controlling the focal lengths of the first lens 1 and the second lens 2, and their proportional relationship to the overall focal length of the first lens group, the refraction and convergence of light can be optimized, thereby improving the clarity of imaging.

[0100] By properly designing the focal lengths of the first lens 1 and the second lens 2 , as well as their proportional relationship with the focal length of the first lens group, distortion can be effectively controlled to make the image more accurate.

[0101] By reasonably designing the focal lengths of the first lens 1 and the second lens 2, as well as their proportional relationship with the focal length of the first lens group, chromatic aberration can be reduced or eliminated, and imaging quality can be improved.

[0102] In some examples of the present application, both the first lens 1 and the second lens 2 have positive refractive power.

[0103] In this example of the present application, the first lens 1 and the second lens 2 are designed to have positive optical power, and the first lens group composed of them also has positive optical power, and the above relationship is satisfied: 4.74≤(f1+f2) / F1≤5; wherein f1 is the focal length of the first lens 1, and f2 is the focal length of the second lens 2.

[0104] In this example of the present application, both the first lens 1 and the second lens 2 have positive focal power, which means that they can converge light. The sum of the focal lengths of the first lens 1 and the second lens 2 and the focal length of the first lens group satisfy 4.74≤(f1+f2) / F1≤5. Since both the first lens 1 and the second lens 2 have positive focal power, they can converge light together, so that the light can be more accurately focused on one point after passing through the first lens group. This helps to improve the clarity of the image, especially in the application of high-definition large exit pupil observation eyepieces.

[0105] A lens with positive focal length can increase the convergence angle of light, thereby enhancing the light collection capability. In the first lens group of the present application, two lenses with positive focal length work together to further improve the light collection efficiency of the eyepiece, so that better imaging effects can be obtained even under low light conditions.

[0106] In some examples of the present application, the second lens group satisfies: 4.34≤(f3+f4) / F2≤4.38; wherein f3 is the focal length of the third lens 3 , and f4 is the focal length of the fourth lens 4 .

[0107] According to 4.34≤(f3+f4) / F2≤4.38 provided in this example of the present application, the focal length ratio relationship reflects the focal length control of the second lens group, which means that there is a balance between the combined focal length of the third lens 3 and the fourth lens 4 and the focal length of the second lens group.

[0108] In this example of the present application, by controlling the ratio of the sum of the focal lengths of the third lens 3 and the fourth lens 4 to the focal length of the second lens group, the light transmission path can be optimized, thereby reducing aberrations and distortions and improving the clarity of the image. This ratio range may help ensure that the light maintains proper diffusion when passing through the eyepiece, thereby providing a sufficiently large exit pupil while ensuring high clarity, suitable for users with different eye distances and pupil sizes.

[0109] In the eyepiece provided in the present application, the first lens group is usually responsible for collecting and focusing light, and its precise coordination with the second lens group (especially f3 and f4 in this example of the present application) can further ensure the imaging quality.

[0110] When (f3+f4) / F2<4.34, it means that the combined focal length of the third lens 3 and the fourth lens 4 is smaller than the overall focal length of the second lens group. This may result in a suboptimal refraction path of light when passing through the two lenses, thereby causing an increase in aberrations and distortions. These aberrations and distortions will directly affect the clarity and accuracy of imaging.

[0111] In addition, a too small ratio may result in insufficient diffusion of light when passing through the eyepiece, thus limiting the size of the exit pupil. The size of the exit pupil is crucial to the comfort and range of use of the eyepiece. If the exit pupil is too small, some users may not be able to use the eyepiece comfortably, especially for users with wider eye distance or smaller pupils.

[0112] When (f3+f4) / F2>4.38, the combined focal length of the third lens 3 and the fourth lens 4 is larger than the overall focal length of the second lens group. This may cause the light to diverge excessively when passing through the two lenses, making it difficult to refocus in subsequent optical elements to form a clear image. In addition, the excessively divergent light may limit the field of view of the eyepiece. The user may not be able to see a sufficiently wide scene, which affects their observation efficiency and experience.

[0113] In some examples of the present application, the third lens 3 and the fourth lens 4 both have negative optical power.

[0114] In this example of the present application, the third lens 3 and the fourth lens 4 are both designed to have negative power, and the second lens group formed by the combination of the two also has negative power. By properly designing a lens with negative power, aberrations introduced by other lenses, such as spherical aberration and chromatic aberration, can be corrected. A lens with negative power helps to expand the field of view of the eyepiece, allowing the observer to see a wider scene.

[0115] In some examples of the present application, the first mirror group satisfies: 2.29≤f1 / f2≤2.59, and the second mirror group satisfies: 1.75≤f4 / f3≤1.81.

[0116] f1 and f2 represent the focal lengths of the first lens 1 and the second lens 2 in the first lens group, respectively. This ratio range ensures the balance of the optical power of the two lenses.

[0117] It should be noted that optical power is a measure of the lens's ability to refract light. A balanced optical power combination helps reduce aberrations and distortion, thereby improving image quality.

[0118] When f1 / f2 is too small, such as less than 2.29, the focal length of the first lens 1 is smaller than the focal length of the second lens 2. This will cause the refraction path of the light after passing through the first lens 1 to be less than optimized, and it will not be able to form a good match with the second lens 2, thereby causing an increase in aberrations and distortions, and reducing the imaging quality.

[0119] In addition, a too small ratio may cause insufficient focusing of the light in the first lens group, so that the light fails to reach an ideal focusing state before entering the second lens group, which will affect the processing of the light by subsequent lenses and further affect the imaging effect of the eyepiece.

[0120] When f1 / f2 is too large, such as greater than 2.59, the focal length of the first lens 1 is too large relative to the focal length of the second lens 2. This will cause the light to be over-focused in the first lens group, so that the light is too concentrated when entering the second lens group, thereby affecting the formation of a large and uniform field of view. Too large a ratio may also cause aberrations and distortion. After passing through the first lens 1, the light may be deflected too much, making it difficult to cooperate with the second lens 2, thereby affecting the image quality.

[0121] f3 and f4 represent the focal lengths of the third lens 3 and the fourth lens 4 in the second lens group, respectively. This ratio range ensures that the combination of the two lenses in terms of optical power can correct the aberration introduced by the first lens group or other lenses. By adjusting the ratio of f3 and f4, the aberration can be further reduced and the image quality can be improved.

[0122] When f4 / f3 is too small, such as less than 1.75, the focal length of the fourth lens 4 is smaller than the focal length of the third lens 3. This will result in the fourth lens 4 having insufficient correction capability for the aberration and distortion introduced by the third lens 3, thereby affecting the image quality. An excessively small ratio may result in insufficient diffusion of light in the second lens group, thereby limiting the field of view of the eyepiece.

[0123] When f4 / f3 is too large, such as greater than 1.81, the focal length of the fourth lens 4 is too large relative to the focal length of the third lens 3. This will cause excessive diffusion of light in the second lens group, making it difficult to refocus the light to form a clear image. An excessively large ratio may also cause an increase in aberrations and distortions, because the light may be deflected too much after passing through the fourth lens 4, making it difficult to cooperate with subsequent optical elements.

[0124] When the ratios of f1 / f2 and f4 / f3 exceed the given range, it may have an adverse effect on the imaging quality and field of view of the eyepiece. Therefore, when designing the eyepiece, the present application controls these ratios to ensure that the eyepiece has excellent performance and user experience.

[0125] In some examples of the present application, the eyepiece satisfies: 4.35≤|(F1+F2) / TG|≤4.52; wherein TG is the interval between the first lens group and the second lens group.

[0126] In this example of the present application, F1 and F2 represent the focal lengths of the first lens group and the second lens group, respectively, and TG represents the interval between the first lens group and the second lens group, that is, the interval between the second lens 2 and the third lens 3. This formula describes the proportional relationship between the sum of the focal lengths of the two lens groups and the interval between them.

[0127] By controlling the ratio of the sum of the focal lengths of the two lens groups and their spacing, various aberrations can be effectively corrected, thereby improving the image quality of the eyepiece. The reduction of aberrations directly improves the clarity of the image, allowing the observer to see more detailed images through the eyepiece.

[0128] In addition, optimizing the relationship between focal length and spacing helps achieve a larger exit pupil diameter, which is especially important for observers who require a wide field of view or wear glasses.

[0129] In some examples of this application, see Figure 1 The polarization reflection element 5 and the phase retarder 6 are arranged on the surface of the first lens 1 close to the exit pupil side; the beam splitter element 7 is arranged on the surface of the fourth lens 4 close to the exit pupil side.

[0130] In this example of the present application, the polarization reflection element 5 and the phase retarder 6 are arranged on the surface of the first lens 1 close to the exit pupil side, and the beam splitter element 7 is arranged on the surface of the fourth lens 4 close to the exit pupil side.

[0131] The polarized reflective element 5 and the phase retarder 6 can be designed to be stacked to form a composite film material, which brings convenience to the film lamination process. The phase retarder 6 is, for example, a quarter wave plate.

[0132] The combination of the polarization reflection element 5 and the phase retarder 6 can effectively manage the polarization state of light. By arranging them on the surface of the first lens 1 close to the exit pupil side, it can be ensured that the light has been optimized before entering the observer's eyes, thereby reducing adverse factors such as glare and ghosting, and improving the clarity and contrast of observation.

[0133] The light splitting element 7 is, for example, a semi-transparent and semi-reflective film, which can be disposed on the surface of the fourth lens 4 by coating or pasting.

[0134] The polarized reflection element 5, the phase retarder 6 and the beam splitter 7 are respectively arranged at specific positions of the first lens 1 and the fourth lens 4, which not only optimizes the optical effect, but also helps to improve the integration of the eyepiece. This configuration makes the entire sighting lens more compact and lightweight, which is conducive to improving the user experience and portability.

[0135] In some examples of this application, see Figure 1 A polarizing element 8 is provided on a surface of the fourth lens 4 which is away from the exit pupil side.

[0136] The polarizing element 8 is a polarizing film, which is an optical film that can selectively transmit or reflect light of a specific vibration direction. Introducing the polarizing element 8 in the eyepiece of the present application can achieve polarization control of light, thereby improving the viewing experience and enhancing the contrast and clarity of the image.

[0137] For example, the introduction of the polarizing element 8 can significantly reduce glare and reflected light from water, snow, smooth surfaces, etc., which often interfere with the viewer's vision and reduce the visibility of the image.

[0138] For another example, the polarization element 8 can enhance the contrast between different objects in the image by filtering out unnecessary polarized light, making the observed target more prominent and easier to identify.

[0139] The polarizing element 8 is arranged on a side surface of the fourth lens 4 away from the exit pupil side, so that the light can be polarized after passing through the main optical components of the eyepiece, thereby more effectively utilizing the function of the polarizing element. This design can also reduce interference with the internal structure of the eyepiece and maintain the compactness and lightness of the eyepiece.

[0140] In some examples of this application, see Figure 1 The first lens 1 is a plano-convex spherical mirror, the second lens 2 is a convex-concave aspherical mirror, the third lens 3 is a concave-convex spherical mirror, and the fourth lens 4 is a plano-convex spherical mirror.

[0141] The first lens 1 is a plano-convex spherical lens: one side of the plano-convex spherical lens is a flat surface, and the other side is a convex spherical surface. This design helps to correct astigmatism and field curvature while maintaining a wide field of view.

[0142] The second lens 2 is a convex-concave aspheric lens: one side of the convex-concave aspheric lens is convex and the other side is concave. The aspheric design can more effectively correct various aberrations, such as spherical aberration, coma, etc., thereby improving the clarity of the image. At the same time, the convex-concave design helps to control the refraction path of light and achieve more precise optical performance.

[0143] The third lens 3 is a concave-convex spherical mirror: one side of the concave-convex spherical mirror is convex and the other side is concave. This design can correct aberrations to a certain extent while maintaining a relatively simple manufacturing process. The concave-convex spherical mirror helps to balance the refraction of light of different wavelengths and improve color reproduction.

[0144] The fourth lens 4 is a plano-convex spherical lens: the plano-convex spherical lens helps to further correct astigmatism and field curvature, and it can also provide additional focusing ability to ensure that the light can form a clear image when it reaches the observer's eyes.

[0145] Wherein, the first lens 1 to the fourth lens 4 may all be made of glass material.

[0146] By combining different types of lenses, especially the use of aspherical lenses, aberrations can be significantly reduced and image clarity can be improved.

[0147] The lenses in this application have flexibility in material selection, and can be made of all plastic or all glass to meet different application requirements and cost considerations. In terms of surface design, the lenses can be made of all aspherical surfaces, which can more effectively correct aberrations and improve image clarity and quality. In addition, the concave and convex directions of the lenses can also be converted to adapt to different optical designs and performance requirements.

[0148] In some examples of the present application, the exit pupil distance EP of the eyepiece is 15mm~25mm, the exit pupil diameter ED of the eyepiece is 25mm~35mm, the aperture NA of the eyepiece is 1.337~1.872, the image height h of the eyepiece is 9.2mm~13mm, and the FOV of the eyepiece is 11.2°~15.9°.

[0149] In this example of the present application, the eyepiece has an exit pupil distance EP of 15 mm to 25 mm, which allows the observer to clearly see the image in the eyepiece while maintaining a certain comfortable distance. A longer exit pupil distance helps reduce the observer's eye fatigue, especially when used for a long time, and can improve the comfort and durability of observation.

[0150] In this example of the present application, the exit pupil diameter ED of the eyepiece is 25 mm to 35 mm, which provides sufficient light channels so that the observer can obtain a wider field of view. This is particularly important in scenes that require wide-range observation, and can improve the observer's ability to capture environmental information.

[0151] In this example of the present application, the aperture NA of the eyepiece is set to 1.337-1.872, which not only ensures that sufficient light enters the eyepiece, but also avoids glare or image distortion caused by excessive light. By controlling the aperture size, the eyepiece of the present application can provide stable imaging effects under different lighting conditions and adapt to various complex environments.

[0152] In this example of the present application, the image height h of the eyepiece is controlled within the range of 9.2 mm to 13 mm, ensuring the accuracy and clarity of the imaging. Reasonable image height setting helps to reduce aberration and distortion and improve the recognition and accuracy of the image.

[0153] In this example of the present application, the field of view of the eyepiece is 11.2° to 15.9°, which enables the observer to observe a wider area without moving the head in the field of aiming lenses. However, this is different from the application of traditional folded optical paths in VR. The present application achieves a large aperture effect in a small field of view.

[0154] Through these key parameters, the overall performance of the eyepiece has been significantly improved. Whether in terms of clarity, contrast, brightness or field of view, the eyepiece performs well and meets various high-precision and high-demand application scenarios.

[0155] In some examples of this application, see Figure 1 The lens module also includes an objective lens system 9, which is located on a side of the eyepiece away from the exit pupil side.

[0156] In the lens module provided in the embodiment of the present application, the objective lens system 9 is located on the side of the eyepiece away from the exit pupil side, and can receive light from the observed object.

[0157] By rationally designing the parameters of the objective lens system 9 (such as focal length, aperture, etc.), the light collecting capability of the lens module can be significantly enhanced, thereby increasing the light throughput and brightness of the lens module.

[0158] After the objective lens system 9 is introduced, the optical performance of the lens module can be further improved. The objective lens system 9 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 9 is more obvious in long-distance observation or in a dark environment.

[0159] After the objective lens system 9 is introduced, the application field of the lens module can be further expanded.

[0160] In some examples of the present application, when the light received by the objective lens system 9 is infrared light, the lens module further includes a display screen 10 , and the display screen 10 is located between the second lens group and the objective lens system 9 .

[0161] When the light received by the objective lens system 9 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 10, the infrared imaging results can be displayed in real time, providing users with an intuitive observation experience.

[0162] In some examples of the present application, a graticule mark is displayed on the display screen 10 ; the objective lens system 9 includes a shooting device, which is electrically connected to the display screen 10 , and the target image shot by the shooting device can be displayed through the display screen 10 .

[0163] The graticule marks displayed on the display screen 10 provide an intuitive reference frame for the user. The user can use these graticules to more accurately locate the observation target, especially in scenes that require precise measurement or aiming. This design can significantly improve the precision and accuracy of observation.

[0164] The electrical connection between the shooting device and the display screen 10 enables the target image shot by the shooting device to be displayed in real time on the display screen 10. This real-time image display function facilitates the user to make instant observation and judgment.

[0165] Through the reticle marks and real-time image display function on the display screen 10, the user can observe more intuitively and conveniently. This design not only improves the practicality of the lens module, but also enhances the user experience.

[0166] In some examples of the present application, when the light received by the objective lens system 9 is visible light, the objective lens system 9 is located on a side of the second lens group away from the exit pupil side, and the objective lens system 9 and the second lens group are spaced apart.

[0167] When visible light passes through the objective lens system 9, it is focused and forms a clear image on a certain plane, which is the image plane of the objective lens system 9. Since there is a gap between the objective lens system 9 and the second lens group of the eyepiece, the gap provides the necessary space for the formation of the image plane.

[0168] According to this example of the present application, the spacing setting allows the light to diffuse and focus at a sufficient distance after passing through the objective lens system 9, 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 9 and the second lens group, which may reduce the imaging quality, and the spacing setting helps to reduce these adverse effects.

[0169] According to another embodiment of the present application, an optical lens is provided, which includes a housing and the lens module as described above.

[0170] The eyepiece in the present application is further described below through Example 1 and Example 2.

[0171] Example 1

[0172] The eyepiece provided in this embodiment 1 is shown in FIG. Figure 1 , comprising a first lens group and a second lens group arranged along the same optical axis, wherein the first lens group is located on the exit pupil side, and the second lens group is located on the focal plane side;

[0173] The first lens group includes a first lens 1 and a second lens 2, the first lens group has positive optical power, wherein the first lens 1 and the second lens 2 both have positive optical power;

[0174] The second lens group includes a third lens 3 and a fourth lens 4, the second lens group has negative optical power, wherein the third lens 3 and the fourth lens 4 both have negative optical power;

[0175] The first lens 1 is a plano-convex spherical mirror, the second lens 2 is a convex-concave aspherical mirror, the third lens 3 is a concave-convex spherical mirror, the fourth lens 4 is a plano-convex spherical mirror, and the first lens 1 to the fourth lens 4 are all made of glass;

[0176] The eyepiece further comprises a polarized reflection element 5, a phase retarder 6 and a beam splitter 7. The polarized reflection element 5 and the phase retarder 6 are arranged on the surface of the first lens 1 close to the exit pupil side; the beam splitter 7 is arranged on the surface of the fourth lens 4 close to the exit pupil side;

[0177] Wherein, the focal length F1 of the first lens group is 98.81 mm, and the focal length F2 of the second lens group is -139.1 mm;

[0178] The total focal length f of the eyepiece is 46.8 mm, and the total system length of the eyepiece is 31 mm;

[0179] The eyepiece has an exit pupil distance EP of 15 mm to 25 mm, and an exit pupil diameter ED of 25 mm to 35 mm;

[0180] The aperture NA of the eyepiece is 1.337-1.872;

[0181] The image height h of the eyepiece is 9.2 mm to 13 mm;

[0182] The FOV of the eyepiece is 11.2° to 15.9°.

[0183] Table 1 shows the optical parameters of each lens in the eyepiece, which are as follows.

[0184] Table 1

[0185]

[0186] Example 2

[0187] 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:

[0188] Wherein, the focal length F1 of the first lens group is 99.75 mm, and the focal length F2 of the second lens group is -139.5 mm;

[0189] The total focal length f of the eyepiece is 46.8 mm, and the total system length of the eyepiece is 30.9 mm;

[0190] The eyepiece has an exit pupil distance EP of 15 mm to 25 mm, and an exit pupil diameter ED of 25 mm to 35 mm;

[0191] The aperture NA of the eyepiece is 1.337-1.872;

[0192] The image height h of the eyepiece is 9.2 mm to 12.4 mm;

[0193] The FOV of the eyepiece is 11.2° to 15.1°.

[0194] The optical parameters of each lens in the eyepiece are shown in Table 2.

[0195] Table 2

[0196]

[0197] 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 distortion diagram, Figure 5 This is the vertical axis chromatic aberration diagram.

[0198] See also Figure 2In the eyepieces provided in Example 1 and Example 2, the maximum value of the image point in the point array diagram is less than 8 μm.

[0199] See also Figure 3 , the eyepieces provided in Example 1 and Example 2 have an MTF of >0.6 at 30lp / mm.

[0200] 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 8%, and the distortion is very small.

[0201] See also Figure 5 The eyepieces provided in Example 1 and Example 2 have a maximum chromatic aberration value of less than 16 μm.

[0202] 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.

[0203] 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: Includes eyepiece; The eyepiece includes a first lens group and a second lens group arranged along the same optical axis on the exit pupil side; The first lens group comprises a first lens (1) and a second lens (2), and the first lens group has positive optical power; The second lens group comprises a third lens (3) and a fourth lens (4), and the second lens group has negative optical power; The eyepiece further comprises a beam splitter (7), a phase retarder (6) and a polarized reflection element (5); the beam splitter (7) is arranged on a side of the fourth lens (4) close to the exit pupil; the polarized reflection element (5) is arranged on a side of the first lens (1) close to the exit pupil; and the phase retarder (6) is located between the beam splitter (7) and the polarized reflection element (5).

2. The lens module according to claim 1, characterized in that: The eyepiece satisfies: 6.5 mm ≤ F1 + F2 + f ≤ 7.1 mm; 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 1, characterized in that: The eyepiece satisfies: 0.6<(EP×ED) / (f×h)<2.03; wherein EP is the exit pupil distance of the eyepiece, ED is the exit pupil diameter of the eyepiece, f is the total focal length of the eyepiece, and h is the image height of the eyepiece.

4. The lens module according to claim 3, characterized in that: The eyepiece satisfies: 0.6<EP / (NA×h)<2.03; wherein NA is the aperture of the eyepiece.

5. The lens module according to claim 1, characterized in that: The first lens group satisfies: 4.74≤(f1+f2) / F1≤5; Wherein, f1 is the focal length of the first lens (1), f2 is the focal length of the second lens (2), and F1 is the focal length of the first lens group.

6. The lens module according to claim 5, characterized in that: The first lens (1) and the second lens (2) both have positive refractive power.

7. The lens module according to claim 1, characterized in that: The second lens group satisfies: 4.34≤(f3+f4) / F2≤4.38; Wherein, f3 is the focal length of the third lens (3), f4 is the focal length of the fourth lens (4), and F2 is the focal length of the second lens group.

8. The lens module according to claim 7, characterized in that: The third lens (3) and the fourth lens (4) both have negative optical power.

9. The lens module according to claim 1, characterized in that: The first mirror group satisfies: 2.29≤f1 / f2≤2.59, and the second mirror group satisfies: 1.75≤f4 / f3≤1.

81.

10. The lens module according to claim 1, characterized in that: The eyepiece satisfies: 4.35≤|(F1+F2) / TG|≤4.52; Wherein, TG is the distance between the first mirror group and the second mirror group.

11. The lens module according to claim 1, characterized in that: The polarized reflection element (5) and the phase retarder (6) are stacked and arranged on a surface of the first lens (1) close to the exit pupil side; The light splitting element (7) is arranged on a surface of the fourth lens (4) close to the exit pupil side.

12. The lens module according to claim 11, characterized in that: A polarizing element (8) is provided on a surface of the fourth lens (4) which is away from the exit pupil side.

13. The lens module according to claim 1, characterized in that: The first lens (1) is a plano-convex spherical mirror, the second lens (2) is a convex-concave aspherical mirror, the third lens (3) is a concave-convex spherical mirror, and the fourth lens (4) is a plano-convex spherical mirror.

14. The lens module according to claim 1, characterized in that: The exit pupil distance EP of the eyepiece is 15 mm to 25 mm, the exit pupil diameter ED of the eyepiece is 25 mm to 35 mm, the aperture NA of the eyepiece is 1.337 to 1.872, the image height h of the eyepiece is 9.2 mm to 13 mm, and the FOV of the eyepiece is 11.2° to 15.9°.

15. The lens module according to claim 1, characterized in that: The lens module also includes an objective lens system (9), and the objective lens system (9) is located on a side of the eyepiece away from the exit pupil side.

16. The lens module according to claim 15, characterized in that: When the light received by the objective lens system (9) is infrared light, the lens module further comprises a display screen (10), and the display screen (10) is located between the second lens group and the objective lens system (9).

17. The lens module according to claim 16, characterized in that: The display screen (10) displays a dividing line mark; The objective lens system (9) comprises a shooting device, which is electrically connected to the display screen (10), and the target image shot by the shooting device can be displayed through the display screen (10).

18. The lens module according to claim 15, characterized in that: When the light received by the objective lens system (9) is visible light, the objective lens system (9) is located on a side of the second lens group away from the exit pupil side, and the objective lens system (9) and the second lens group are arranged at an interval.

19. An optical lens, characterized in that: include: shell; and A lens module as described in any one of claims 1-18.

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