Optical lens and camera module

Abstract

This application discloses an optical lens and a camera module. The optical lens includes a first lens group, a second lens group, and a third lens group. The first and third lens groups both have positive optical power, while the second lens group has negative optical power. The second lens group can move relative to the first lens group along the optical axis, enabling the optical lens to switch between a conventional observation position and a close-up magnified observation position. The first lens group includes a first lens, a second lens, and a third lens. The focal length f of the second and third lenses is... m The focal length f of the optical lens in the normal observation position w Satisfying the relation: -70 <f m / f w <-2; The focal length f2 of the second lens group and the focal length f of the optical lens in the normal observation position. w The relation satisfies: -4.5 <f2 / f w <-1.5. This optical lens achieves a balance between high zoom efficiency, low tolerance sensitivity, and high image quality during zooming.

Description

Technical Field

[0001] This application relates to the field of camera technology, and in particular to an optical lens and camera module. Background Technology

[0002] For professional cameras, different types of optical lenses are often required in different scenarios. For example, in the medical field, in order to make precise diagnoses of lesions, optical lenses with zoom and focus capabilities are needed as endoscope objectives. Zoom and focus of an optical lens is achieved by moving part of the lens within the optical lens, thereby changing the focal length of the optical lens and realizing the magnified observation requirements from normal observation to close-up observation.

[0003] In recent years, in the medical field, in order to improve the accuracy of precise diagnosis of lesions, how to develop an optical lens with zoom function that can achieve both high zoom efficiency and high image quality with good aberration correction during zooming has become an important issue in the industry. Summary of the Invention

[0004] The embodiments of this application provide an optical lens and camera module that can effectively balance high zoom efficiency, low tolerance sensitivity, and high image quality.

[0005] In a first aspect, embodiments of this application provide an optical lens, including a first lens group, a second lens group, and a third lens group arranged from the object side to the image side. The first lens group and the third lens group both have positive optical power, while the second lens group has negative optical power. The second lens group is movable relative to the first lens group along the optical axis, enabling the optical lens to switch between a conventional observation position and a close-up magnified observation position. The first lens group includes a first lens, a second lens, and a third lens arranged from the object side to the image side, and the focal length f of the second lens and the third lens... m The focal length f of the optical lens during normal observation w Satisfies the relation: -70 <f m / f w <-2; The focal length f2 of the second lens group is the same as the focal length f of the optical lens during normal observation. w The relation satisfies: -4.5 <f2 / fw<-1.5。

[0006] The beneficial effects of the optical lens provided in this application embodiment are as follows: by reasonably allocating the optical power of the first lens group, the second lens group, and the third lens group, and simultaneously controlling the ratio of the focal length of the second and third lenses in the first lens group to the focal length of the optical lens during normal observation, and the ratio of the focal length of the second lens group to the focal length of the optical lens during normal observation, the optical lens can switch between normal observation position and close magnification observation position. This not only helps to balance the optical power of the first lens group, the second lens group, and the third lens group to reduce aberrations and improve image quality, but also achieves the goal of balancing a large depth of field, high magnification efficiency, and low tolerance sensitivity during the zoom switching process between normal observation and close magnification observation.

[0007] In some embodiments, the first lens group further includes a fourth lens and a fifth lens arranged sequentially along the object side to the image side of the third lens on the image side, wherein the first lens and the fourth lens both have negative optical power, the second lens and the third lens both have optical power, the fifth lens has positive optical power, and the second lens and the third lens are cemented lenses.

[0008] The above configuration not only allows for a more flexible allocation of the optical power of each lens in the first lens group, enabling the optical power of the first lens group to be well balanced with that of the second and third lens groups, thereby reducing aberrations and improving the imaging quality of the optical lens, but also, since the first lens group includes five lenses, it helps to reduce the overall optical length of the optical lens and facilitates the miniaturization of the optical lens design.

[0009] In some embodiments, the second lens and the third lens are cemented lenses, and the fourth lens and the fifth lens are cemented lenses.

[0010] With the above configuration, the first lens group includes two cemented lenses. This not only further eliminates chromatic aberration and spherical aberration of the optical lens, but also reduces tolerance sensitivity and improves the imaging quality of the optical lens. Furthermore, it reduces the installation steps of the optical lens and facilitates its assembly.

[0011] In some embodiments, the focal length f2 of the second lens group and the focal length f3 of the third lens group satisfy the following relationship: -2 <f2 / f3<-0.5。

[0012] A reasonable allocation of optical power helps to balance the aberrations produced by the second and third lens groups, improves image quality, and simplifies the structure, which helps to reduce the total optical length of the optical lens.

[0013] In some embodiments, the focal length f1 of the first lens group and the focal length f2 of the second lens group satisfy the relationship: -0.7 <f1 / f2<-0.3。

[0014] By allocating optical power reasonably and controlling the ratio within the above range, it is not only beneficial to balance the aberrations generated by the first lens group and the second lens group, but also to reduce tolerance sensitivity and thus improve imaging quality. It can also be applied to small-aperture application scenarios.

[0015] In some embodiments, the second lens group includes a sixth lens and a seventh lens arranged from the object side to the image side, wherein the sixth lens and the seventh lens are cemented lenses.

[0016] By designing the sixth and seventh lenses as cemented lenses, not only can the travel of the moving lenses be reduced to improve zoom efficiency, but the tolerance sensitivity of the moving lenses during zooming can also be suppressed. Furthermore, the movement of the cemented lenses increases the aperture number at the magnified observation position, which is more conducive to increasing the depth of field. This makes the focal length adjustment range smaller and easier to operate when moving from the normal observation position to the magnified observation position, eliminating the need for frequent focusing.

[0017] In some embodiments, the third lens group includes an eighth lens, a ninth lens, and a tenth lens arranged from the object side to the image side, wherein the eighth lens and the ninth lens both have positive optical power, and the tenth lens has negative optical power.

[0018] The above settings not only allow for more flexible allocation of the optical power of each lens in the third lens group, but also enable the optical power of the third lens group to be well balanced with that of the first and second lens groups, thereby reducing aberrations and improving the imaging quality of the optical lens.

[0019] In some embodiments, the ninth and tenth lenses are cemented lenses.

[0020] With the above settings, not only can chromatic aberration and spherical aberration of the optical lens be further eliminated, but the assembly of the optical lens can also be facilitated.

[0021] In some embodiments, the third lens group has a filter on the side closer to the image side.

[0022] The above settings not only improve the imaging quality of the optical lens, but also broaden its application range.

[0023] In some embodiments, the filter is an infrared cutoff filter.

[0024] By using the above settings, the interference of infrared rays during the imaging process of the optical lens can be reduced, thereby further improving the imaging quality of the optical lens.

[0025] In some embodiments, the filter is provided with a laser cutoff film.

[0026] The above settings make the optical lens suitable for laser therapy.

[0027] Secondly, embodiments of this application also provide a camera module, including a photosensitive element and the optical lens described in the first aspect, wherein the photosensitive element is disposed on the image side of the optical lens.

[0028] The camera module in this embodiment achieves the same technical effect as the optical lens in the first aspect, and will not be described again here. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a structural diagram of the optical lens of Embodiment 1 of this application in a conventional observation position;

[0031] Figure 2 This is a structural diagram of the optical lens of Embodiment 1 of this application when viewed from a close-up magnified position;

[0032] Figure 3 This is an astigmatism image of the optical lens of Embodiment 1 of this application in a conventional observation position;

[0033] Figure 4 This is a distortion diagram of the optical lens of Embodiment 1 of this application in a normal viewing position;

[0034] Figure 5 This is a spherical aberration diagram of the optical lens of Embodiment 1 of this application in a conventional observation position;

[0035] Figure 6 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 1 of this application at a normal viewing position;

[0036] Figure 7 This is an astigmatism image of the optical lens of Embodiment 1 of this application at a close-range magnified observation position;

[0037] Figure 8 This is a distortion diagram of the optical lens of Embodiment 1 of this application at a close-range magnified observation position;

[0038] Figure 9This is a spherical aberration diagram of the optical lens of Embodiment 1 of this application at a close-range magnified observation position;

[0039] Figure 10 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 1 of this application at a close magnified observation position;

[0040] Figure 11 This is a structural diagram of the optical lens of Embodiment 2 of this application in a conventional observation position;

[0041] Figure 12 This is a structural diagram of the optical lens of Embodiment 2 of this application when viewed from a close-up magnified position;

[0042] Figure 13 This is an astigmatism image of the optical lens of Embodiment 2 of this application in a normal observation position;

[0043] Figure 14 This is a distortion diagram of the optical lens of Embodiment 2 of this application in a normal viewing position;

[0044] Figure 15 This is a spherical aberration diagram of the optical lens of Embodiment 2 of this application in a conventional observation position;

[0045] Figure 16 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 2 of this application at a conventional viewing position;

[0046] Figure 17 This is an astigmatism image of the optical lens of Embodiment 2 of this application at a close-range magnified observation position;

[0047] Figure 18 This is a distortion diagram of the optical lens of Embodiment 2 of this application at a close-range magnified observation position;

[0048] Figure 19 This is a spherical aberration diagram of the optical lens of Embodiment 2 of this application at a close-range magnified observation position;

[0049] Figure 20 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 2 of this application at a close magnified observation position;

[0050] Figure 21 This is a structural diagram of the optical lens of Embodiment 3 of this application in a conventional observation position;

[0051] Figure 22 This is a structural diagram of the optical lens of Embodiment 3 of this application when viewed from a close-up magnified position;

[0052] Figure 23 This is an astigmatism image of the optical lens of Embodiment 3 of this application in a normal viewing position;

[0053] Figure 24 This is a distortion diagram of the optical lens of Embodiment 3 of this application in a normal viewing position;

[0054] Figure 25 This is a spherical aberration diagram of the optical lens of Embodiment 3 of this application in a conventional observation position;

[0055] Figure 26 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 3 of this application at a normal viewing position;

[0056] Figure 27 This is an astigmatism image of the optical lens of Embodiment 3 of this application at a close-range magnified observation position;

[0057] Figure 28 This is a distortion diagram of the optical lens of Embodiment 3 of this application at a close-range magnified observation position;

[0058] Figure 29 This is a spherical aberration diagram of the optical lens of Embodiment 3 of this application at a close-range magnified observation position;

[0059] Figure 30 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 3 of this application at a close magnified observation position;

[0060] Figure 31 This is a structural diagram of the optical lens of Embodiment 4 of this application in a conventional observation position;

[0061] Figure 32 This is a structural diagram of the optical lens of Embodiment 4 of this application when viewed from a close-up magnified position;

[0062] Figure 33 This is an astigmatism image of the optical lens of Embodiment 4 of this application in a normal viewing position;

[0063] Figure 34 This is a distortion diagram of the optical lens of Embodiment 4 of this application in a normal viewing position;

[0064] Figure 35 This is a spherical aberration diagram of the optical lens of Embodiment 4 of this application in a conventional observation position;

[0065] Figure 36 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 4 of this application at a normal viewing position;

[0066] Figure 37 This is an astigmatism image of the optical lens of Embodiment 4 of this application at a close-range magnified observation position;

[0067] Figure 38 This is a distortion diagram of the optical lens of Embodiment 4 of this application at a close-range magnified observation position;

[0068] Figure 39 This is a spherical aberration diagram of the optical lens of Embodiment 4 of this application at a close-range magnified observation position;

[0069] Figure 40 This is a magnification chromatic aberration diagram of the optical lens of Embodiment 4 of this application at a close magnified observation position.

[0070] The following are the labeling elements in the figure:

[0071] First lens group G1; Second lens group G2; Third lens group G3; First lens L1; Second lens L2; ​​Third lens L3; Fourth lens L4; Fifth lens L5; Sixth lens L6; Seventh lens L7; Eighth lens L8; Ninth lens L9; Tenth lens L10; Filter L11; Aperture STO; Positioning glass plate L12; Protective glass plate L13. Detailed Implementation

[0072] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0073] Focal power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical lens to deflect light.

[0074] A lens or lens group with positive optical power, having a positive focal length, and having the effect of converging light.

[0075] A lens or lens group with negative optical power has a negative focal length and has the effect of diverging light.

[0076] Focal length, also known as focal length, is a measure of how well light converges or diverges in an optical lens. It refers to the perpendicular distance from the optical center of a lens or lens group to the focal plane when a distant object is focused into a clear image. For prime lenses, the position of their optical center remains constant; for telephoto lenses, changes in the optical center result in changes in the focal length.

[0077] Back focal length FBL is the length from the rearmost point of the optical system to the imaging plane.

[0078] Total Track Length (TTL) refers to the distance from the center of the lens to the focal point where light converges; in other words, within a module, it is the distance from the center of the lens to the imaging plane of the sensor surface.

[0079] The object side is defined by the lens; the side where the object is located is called the object side, and the surface of the lens closest to the object side is called the object side surface.

[0080] The image side is the side on which the image of the object is located, with the lens as the boundary. The surface of the lens closest to the image side is called the image side surface.

[0081] An aperture diaphragm is a device used to control the amount of light passing through the lens and entering the sensor inside the camera body; it is usually located inside the lens.

[0082] Aperture number, also known as F-number (FNO), is a relative value derived from the lens's focal length and entrance pupil diameter (the reciprocal of the relative aperture). A smaller aperture number allows more light to enter the lens in the same unit of time. A larger aperture number results in a shallower depth of field, blurring the background and creating an effect similar to a telephoto lens.

[0083] Total track length (TTL) refers to the total length from the surface of the lens closest to the object to the imaging plane. TTL is a major factor in determining the height of the camera.

[0084] The imaging plane is located on the image side of all lenses in an optical lens, and is the surface on which the image is formed after light passes through each lens in the optical lens.

[0085] The optical axis is a vertical axis that passes through the center of a lens. The lens optical axis is the axis that passes through the centers of each lens in the lens.

[0086] The focal point is the point where parallel light rays converge after being refracted by a lens or lens group.

[0087] Aberrations: Optical lenses have the properties of an ideal optical system at the optical axis, where near-axis rays emitted from a point on an object intersect the image plane at a point (i.e., the optical axis image point). However, in reality, rays passing through different apertures of the lens rarely intersect perfectly at a single point, but rather deviate from the position of the near-axis image point. These differences are collectively referred to as aberrations.

[0088] Spherical aberration occurs when light rays entering a spherical lens are more easily refracted and bent at the edges of the lens compared to the center. This results in reduced sharpness and contrast, as well as the formation of bokeh, thus degrading image quality. The larger the aperture, the more severe the aberration. Stopping down the aperture can improve the situation, but it cannot completely eliminate it. This aberration caused by spherical lenses is called spherical aberration.

[0089] Distortion, also known as image distortion, refers to the degree of distortion in the image formed by an optical lens relative to the object itself. Distortion is caused by the spherical aberration of the aperture. The height of the intersection point between the principal ray and the Gaussian image plane after passing through the optical lens in different fields of view is not equal to the ideal image height; the difference between the two is the distortion.

[0090] Astigmatism occurs because the object point is not on the optical axis of the lens, causing the emitted beam of light to be tilted at an angle to the optical axis. After refraction by the lens, the convergence points of the meridional and sagittal beams are not at the same point. In other words, the beam cannot be focused at a single point, resulting in an unclear image and thus astigmatism. The meridional and sagittal beams are the names of the beams within two perpendicular planes of a rotationally symmetric optical lens.

[0091] The meridional plane is the plane formed by the principal ray (principal beam) of an object point outside the optical axis and the optical axis.

[0092] The sagittal surface is the plane that passes through the principal ray (principal beam) of an object point outside the optical axis and is perpendicular to the meridional plane.

[0093] Field curvature refers to the difference in optical axis between the position of the sharpest image point after rays from the off-center field of view pass through an optical lens assembly and the position of the sharpest image point in the center field of view. When a lens has field curvature, the intersection of the entire beam does not coincide with the ideal image point. Although a sharp image point can be obtained at each specific point, the entire image plane is a curved surface.

[0094] Magnification chromatic aberration is a color difference caused by the difference in image size due to the different imaging heights (i.e., magnification) of different colored lights.

[0095] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0096] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0097] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0099] For professional cameras, different types of optical lenses are often required in different scenarios. For example, in the medical field, in order to make precise diagnoses of lesions, optical lenses with zoom and focus capabilities are needed as endoscope objectives. Zoom and focus of an optical lens is achieved by moving part of the lens within the optical lens, thereby changing the focal length of the optical lens and realizing the magnified observation position required from the normal observation position to a close-up observation position.

[0100] In recent years, in the medical field, in order to improve the accuracy of precise diagnosis of lesions, how to develop an optical lens with zoom function that can achieve high zoom efficiency, low tolerance sensitivity and good aberration correction and high image quality during zooming has become an important issue in the industry.

[0101] To address the aforementioned technical problems, this application provides an optical lens comprising a first lens group, an aperture stop, a second lens group, and a third lens group arranged from the object side to the image side. By rationally allocating the optical power of the first, second, and third lens groups, and simultaneously controlling the ratio of the focal lengths of the second and third lenses in the first lens group to the focal length of the optical lens in the conventional observation position, and the ratio of the focal length of the second lens group to the focal length of the optical lens in the conventional observation position, the optical lens can switch between the conventional observation position and the close-range magnification observation position. This not only helps to balance the optical power of the first, second, and third lens groups to reduce aberrations and improve image quality, but also achieves a balance between high zoom efficiency, low tolerance sensitivity, and high image quality during the zoom switching process between the conventional observation position and the close-range magnification observation position.

[0102] This application provides a camera module, including as follows: Figure 1 , Figure 11 , Figure 21 and Figure 31The optical lens and sensing element shown are configured such that the photosensitive element is located on the image side of the optical lens (e.g., ...). Figure 1 (As shown on the far right).

[0103] The aforementioned photosensitive element can be a CCD (Charge Coupled Device) image sensor or a CMOS image sensor. In some embodiments, to protect the photosensitive element and facilitate its placement, it is fixed together with a protective glass plate L13. Furthermore, to improve the imaging quality of the optical lens, a positioning glass plate L12 is typically provided on the object side of the protective glass plate L13 near the optical lens. This allows the photosensitive element to be positioned by adjusting the relative position between the protective glass plate L13 and the positioning glass plate L12, improving the installation accuracy of the photosensitive element and thus contributing to improved imaging quality of the optical lens.

[0104] The aforementioned camera module can be used in electronic devices with video and photo-taking capabilities. This electronic device can be an endoscope with a camera function. Of course, besides endoscopes with camera functions, other electronic devices with camera functions can also be used; no specific limitation is made here.

[0105] like Figure 1 and Figure 2 As shown, this application provides an optical lens including a first lens group G1, a second lens group G2, and a third lens group G3 arranged from the object side to the image side. The first lens group G1 and the third lens group G3 both have positive optical power, while the second lens group G2 has negative optical power. The second lens group G2 is movable relative to the first lens group G1 along the optical axis, enabling the optical lens to be positioned in a conventional observation position (e.g., ...). Figure 1 The position shown) and the close-up magnified observation position (such as...) Figure 2 Zoom switching between positions shown; the first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3 arranged from the object side to the image side, the focal length f of the second lens L2 and the third lens L3. m The focal length f of the optical lens in the normal observation position w Satisfies the relation: -70 <f m / f w <-2; The focal length f2 of the second lens group G2 is the same as the focal length f of the optical lens in the normal observation position. w The relation satisfies: -4.5 <f2 / f w <-1.5.

[0106] It should be noted that during the zoom adjustment process of the optical lens, the first lens group G1 and the third lens group G3 are relatively fixed. The zoom adjustment of the optical lens is achieved by moving some or all of the lenses in the second lens group G2. This is an example of the zoom adjustment of the optical lens.

[0107] For example, in the optical lens of Embodiment 1, the second lens group G2 can move between the first lens group G1 and the third lens group G3. For example, the first lens group G1 and the third lens group G3 are fixed, and all the lenses of the second lens group G2, as a whole, can move between the first lens group G1 and the third lens group G3, i.e., in... Figure 1 and Figure 2 The two positions shown are moved relative to the first lens group G1, thereby achieving zoom focusing between the normal observation position and the close-up magnified observation position. Of course, zoom focusing can also be achieved by moving part of the lens in the second lens group G2, or by moving at least two of the first lens group G1, the second lens group G2, and the third lens group G3 relative to each other; no specific limitation is made here.

[0108] Among them, f m / f w and f2 / f w These are two crucial parameters in the design process of optical lenses, directly affecting the zoom efficiency, tolerance sensitivity, and radial footprint (aperture) of the lens. If these parameters are too small, the focal length of the lens becomes smaller, leading to overcorrection of chromatic aberration and poor tolerance sensitivity during zooming, thus compromising image quality. Conversely, if these parameters are too large, the focal length becomes larger, resulting in undercorrection during zooming, decreased image quality, and an increased aperture for the first lens L1 in the first lens group G1, which is unsuitable for applications requiring small apertures and high image quality.

[0109] The optical lens provided in this application embodiment, by reasonably allocating the optical power of the first lens group G1, the second lens group G2, and the third lens group G3, helps to balance the optical power of the first lens group G1, the second lens group G2, and the third lens group G3, thereby reducing aberrations and improving image quality. At the same time, by controlling the ratio of the focal length of the second and third lenses in the first lens group G1 to the focal length of the optical lens in the normal observation position, and the ratio of the focal length of the second lens group G2 to the focal length of the optical lens in the normal observation position, the optical lens can switch between the normal observation position and the close magnification observation position. Thus, during the zoom switching process between the normal observation position and the close magnification observation position, it can achieve the goal of balancing high zoom efficiency, low tolerance sensitivity, and high image quality.

[0110] like Figure 1 and Figure 2 As shown, in some embodiments, the first lens group further includes a fourth lens L4 and a fifth lens L5 arranged sequentially along the object side to the image side of the third lens L3. That is, the first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 arranged along the object side to the image side. The first lens L1 and the fourth lens L4 both have negative optical power, the second lens L2 and the third lens L3 both have optical power, and the fifth lens L5 has positive optical power.

[0111] By rationally allocating the optical power of the five lenses in the first lens group G1, the selection and combination of optical power and focal length of each lens in the first lens group G1 becomes more flexible. This allows the optical power of the first lens group G1 to be better balanced with the optical power of the second lens group G2 and the third lens group G3, thereby helping to reduce aberrations and improve the imaging quality of the optical lens. Moreover, the five lenses in the first lens group G1 help to reduce the overall optical length of the optical lens, which is conducive to the miniaturization design of the optical lens. In this way, the optical lens can achieve the goal of balancing high image quality and miniaturization.

[0112] In some embodiments, the second lens L2 and the third lens L3 are cemented lenses, and the fourth lens L4 and the fifth lens L5 are cemented lenses. That is, the second lens L2 and the third lens L3 can be joined together by a cementing process to form a cemented lens, and the fourth lens L4 and the fifth lens L5 can be joined together by a cementing process to form a cemented lens.

[0113] By configuring the first lens group G1 as described above, two cemented lenses are included, thus maximizing the number of cemented lenses in the first lens group G1. This not only further eliminates chromatic aberration and spherical aberration of the optical lens, but also reduces tolerance sensitivity and increases the incident angle to generate more higher-order aberrations, thereby better offsetting primary aberrations and achieving aberration balance, thus improving the imaging quality of the optical lens. Furthermore, the multiple cemented lenses reduce the installation steps of the optical lens, facilitating its assembly.

[0114] In some embodiments, the focal length f1 of the first lens group G1 and the focal length f2 of the second lens group G2 satisfy the relationship: -0.7 <f1 / f2<-0.3。

[0115] Among these parameters, f1 / f2 are crucial in the design of optical lenses. These parameters are related to the lens aperture, i.e., the radial space occupied by the lens, and the image quality. If these parameters are small, not only will the refractive power of the first lens group G1 be weakened, thus increasing the lens aperture and making it unsuitable for small-aperture applications, but the aberrations of the lens cannot be properly corrected, resulting in poor image quality. If these parameters are large, the focal length of the first lens group G1 will be large. Although this can reduce the lens aperture, it will also introduce greater aberrations, severely degrading image quality and reducing tolerance sensitivity.

[0116] By allocating optical power reasonably and controlling the ratio within the range mentioned above, it is not only beneficial to balance the aberrations generated by the first lens group G1 and the second lens group G2, reduce tolerance sensitivity, and thus improve image quality, but also beneficial to the miniaturization design of optical lenses, especially for applications with small apertures, such as endoscopes.

[0117] In some embodiments, the focal length f2 of the second lens group G2 and the focal length f3 of the third lens group G3 satisfy the following relationship: -2 <f2 / f3<-0.5。

[0118] Among them, f2 / f3 is an important parameter in the optical lens design process. If the above parameters are small, the refractive power of the third lens group G3 will be stronger, which is not conducive to the correction of optical lens aberrations and thus affects image quality. If the above parameters are large, the refractive power of the third lens group G3 will be weaker, and the back focal length of the optical lens will be larger, resulting in a longer overall optical length of the optical lens, which is not conducive to the miniaturization design of the optical lens.

[0119] By rationally allocating optical power and controlling the ratio within the aforementioned range, it is not only beneficial to balance the aberrations generated by the second lens group G2 and the third lens group G3, thus improving image quality, but also to simplify the structure and reduce the total optical length of the optical lens, thereby facilitating the miniaturization design of the optical lens.

[0120] like Figure 1 and Figure 2 As shown, in some embodiments, the second lens group G2 includes a sixth lens L6 and a seventh lens L7 arranged from the object side to the image side, wherein the sixth lens L6 and the seventh lens L7 are cemented lenses.

[0121] Since the second lens group G2 can move along the optical axis according to the change of object distance to adjust the focusing position of the image plane, by designing the sixth lens L6 and the seventh lens L7 as cemented lenses, it is possible not only to reduce the travel of the second lens group G2 and improve the zoom efficiency, but also to suppress the tolerance sensitivity of the second lens group G2 during zoom. Moreover, the movement of the cemented lenses will increase the aperture number at the magnified observation position, which is more conducive to increasing the depth of field. This makes the focal length adjustment range smaller and easier to operate when moving from the normal observation position to the magnified observation position, without the need for frequent focusing. In addition, it is helpful to further eliminate chromatic aberration and spherical aberration, so that the optical lens can achieve the goals of high zoom efficiency, low tolerance sensitivity, miniaturization, and ease of operation.

[0122] like Figure 1 and Figure 2 As shown, in some embodiments, the third lens group G3 includes an eighth lens L8, a ninth lens L9, and a tenth lens L10 arranged from the object side to the image side. The eighth lens L8 and the ninth lens L9 both have positive optical power, and the tenth lens L10 has negative optical power.

[0123] The above configuration allows for a more flexible allocation of the optical power of each lens in the third lens group G3, enabling the optical power of the third lens group G3 to be well balanced with that of the first lens group G2 and the second lens group G2, reducing aberrations and thus improving the imaging quality of the optical lens. Moreover, it helps to reduce the overall optical length of the optical lens, which is beneficial for the miniaturization design of the optical lens.

[0124] In some embodiments, the ninth lens L9 and the tenth lens L10 are cemented lenses. This not only helps to further eliminate chromatic aberration and spherical aberration of the optical lens, but also reduces the number of mounting steps for the optical lens, making the assembly of the optical lens more convenient.

[0125] like Figure 1 and Figure 2 As shown, in some embodiments, the third lens group G3 has a filter L11 on the side closer to the image side.

[0126] Through the above configuration, the optical lens can function as both the entry and exit light path for a specific filter L11 in the optical path. This means the filter L11 can block light or not, thus diversifying the lens's functionality. This not only improves image quality in specific applications but also allows for the selection of different filters L11 to suit various needs, broadening its application range. For example, in the cold light source path of a medical endoscope, without changing the light-emitting components, the bandwidth of a specific monochromatic light in the optical path can be altered to achieve the desired illumination mode for different wavelengths.

[0127] like Figure 1 and Figure 2As shown, in some embodiments, filter L11 is an infrared cutoff filter.

[0128] By implementing the above settings, infrared interference during the imaging process of the optical lens can be reduced, thereby further improving the imaging quality of the optical lens.

[0129] The aforementioned infrared cut-off sheet is short for infrared cut-off filter (also called infrared filter or heat-absorbing filter), a type of filter used to filter infrared wavelengths. For example, when installed on incandescent light equipment (such as slide projectors), it can prevent unnecessary heat from burning the lens; when installed on cameras with solid-state electronic devices (CCD image sensors or CMOS image sensors), it can prevent infrared light from passing through the camera lens and causing image distortion.

[0130] In some embodiments, the filter L11 is provided with a laser cutoff film (not shown in the figure).

[0131] By setting a laser cutoff film on the filter L11, the optical lens can be made suitable for laser therapy.

[0132] The aforementioned laser cutoff film can be a functional film such as a YAG laser cutoff film or an LD laser cutoff film. The laser cutoff film can be set on one side of the filter L11 or on both sides of the filter L11. No specific limitation is made here.

[0133] like Figure 1 and Figure 2 The structure of the optical lens in Embodiment 1 is shown. This optical lens includes a first lens group G1, an aperture stop STO, a second lens group G2, and a third lens group G3 arranged from the object side to the image side. In other words, the optical lens includes... Figure 1 The first lens group G1, the aperture stop STO, the second lens group G2, and the third lens group G3 are arranged from left to right. The first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 arranged from the object side to the image side. The second lens L2 and the third lens L3 are cemented lenses, as are the fourth lens L4 and the fifth lens L5. The second lens group G2 includes a sixth lens L6 and a seventh lens L7 arranged from the object side to the image side. The sixth lens L6 and the seventh lens L7 are cemented lenses. The third lens group G3 includes an eighth lens L8, a ninth lens L9, and a tenth lens L10 arranged from the object side to the image side. The ninth lens L9 and the tenth lens L10 are cemented lenses. A filter L11 is also provided on the side of the tenth lens L10 away from the ninth lens L9.

[0134] As an optional embodiment of this application, based on Embodiment 1 of this application, the parameter values ​​of each lens of the optical lens can be referred to Tables 1a to 1d.

[0135] Table 1a

[0136] Face number Surface type R value Thickness (mm) OBJ Standard Infinity 13(1.5) S1 Standard Infinity 0.60 S2 Standard 1.20 1.01 S3 Standard -2.04 0.90 S4 Standard -2.00 0.60 S5 Standard -3.43 2.53 S6 Standard 1.79 0.75 S7 Standard 1.00 0.80 S8 Standard -3.37 0.74 STO Standard Infinity 0.305(1.34) S10 Standard -3.70 0.30 S11 Standard 1.10 0.65 S12 Standard 6.00 1.59(0.56) S13 Standard 4.43 1.20 S14 Standard -3.24 0.51 S15 Standard 3.80 1.40 S16 Standard -1.92 1.01 S17 Standard -7.90 0.20 S18 Standard Infinity 0.40 S19 Standard Infinity 0.72 S20 Standard Infinity 0.60 S21 Standard Infinity 0.01 S22 Standard Infinity 0.4 IMAGE Standard Infinity /

[0137] It should be noted that in Table 1a, "Surface Number" refers to the number of each surface arranged from the object side to the image side. "Standard" in the surface type represents a standard sphere. The radius R value corresponds to the lens with the surface number, that is, the radius of curvature of the object side or image side of the lens corresponding to each surface number along the optical axis. "Infinite" in the "Radius of Curvature" parameter series indicates that the object side or image side of the lens is a plane. The last "IMAGE" in the "Surface Number" column refers to the image side of the optical lens. Since the optical lens of this application can zoom and focus, "OBJ" refers to the object surface. The two values ​​inside and outside the parentheses in the "Thickness" parameter series for "OBJ" refer to two different object distances of the optical lens. The first value in the "Thickness / Spacing" parameter series for each lens is the thickness of the lens along the optical axis, and the second value is the distance along the optical axis from the image side of the lens to the object side of the next lens. The value of the stop STO in the "Thickness" parameter series is the distance along the optical axis from the center of the stop STO to the object side of the next lens. For example, as... Figure 1 As shown, in this embodiment, when the object distance is 13mm, the distance between the aperture stop STO and the object-side surface of the sixth lens L6 is 0.305mm; when the object distance is 1.5mm, the distance between the aperture stop STO and the object-side surface of the sixth lens L6 is 1.34mm. The values ​​of “S1” to “S22” in the “thickness” parameter series represent the distances between adjacent object-side surfaces, image-side surfaces, and aperture stops STO from the object-side surface of the first lens L1 to the protective glass plate L13, which is the imaging surface of the optical lens. For example, the value of "S1" in the "thickness" parameter series represents the distance between the object side and the image side of the first lens L1, the value of "S2" in the "thickness" parameter series represents the distance between the image side of the first lens L1 and the object side of the second lens L2, the value of "S8" in the "thickness" parameter series represents the distance between the image side of the fifth lens L5 and the aperture STO, and the value of "S12" in the "thickness" parameter series represents the distance between the image side of the seventh lens L7 and the object side of the eighth lens L8. The values ​​inside and outside the parentheses correspond to the corresponding object distances.

[0138] In this embodiment, the total optical length L of the optical lens is 17.258 mm; the F-number at the normal viewing position is 6.32, and the focal length f is... w =0.933mm; F-number for close-up magnification observation position =9.50, focal length f =1.358mm.

[0139] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 1b.

[0140] Table 1b

[0141] parameter <![CDATA[-4.5<f2 / f w <-1.5]]> <![CDATA[-70<f m / f w <-2]]> <![CDATA[-0.7<f1 / f2<-0.3]]> <![CDATA[-2<f2 / f3<-0.5]]> numerical values -2.48 -17.63 -0.53 -0.85

[0142] Note: The following annotations explain the relationships between the optical lenses in the various embodiments:

[0143] f w This is the focal length of the optical lens in the normal viewing position, and is equal to the EFL value of the optical lens;

[0144] f1 is the focal length of the first lens group G1, that is, the focal length of all the lenses in the first lens group G1.

[0145] f2 is the focal length of the second lens group G2, which is the focal length of the sixth lens L6 and the seventh lens L7.

[0146] f m The focal lengths of the second lens L2 and the third lens L3;

[0147] The positive and negative values ​​of the optical power of each lens in the optical lens in this embodiment are shown in Table 1c.

[0148] Table 1c

[0149]

[0150] It should be noted that the "+" and "-" in Table 1c represent the positive and negative optical power of each lens in the optical lens of Example 1. "+" indicates that the lens has positive optical power; "-" indicates that the lens has negative optical power.

[0151] The concavity or convexity of the object side or image side of each lens in the optical lens of Embodiment 1 at the optical axis is shown in Table 1d.

[0152] Table 1d

[0153]

[0154] It should be noted that “++”, “+-”, “-+”, “∞+”, “+∞”, “--”, “∞-”, and “-∞” in Table 1d represent the concavity or convexity of the object side or image side at the optical axis in each lens. Among them, "++" represents that both the object side and image side of the lens are convex towards the object side at the optical axis; "+-" represents that both the object side and image side of the lens are convex towards the object side at the optical axis, i.e., a double-convex crescent structure; "-+" represents that both the object side and image side of the lens are concave towards the object side at the optical axis, i.e., a double-concave structure; "∞+-" represents that the object side of the lens is flat at the optical axis, and the image side is convex towards the object side at the optical axis; "+∞" represents that the object side of the lens is convex towards the object side at the optical axis, and the image side is flat at the optical axis; "--" represents that both the object side and image side of the lens are concave towards the object side at the optical axis; "∞-" represents that the object side of the lens is flat at the optical axis, and the image side is concave towards the object side at the optical axis; "-∞" represents that the object side of the lens is concave towards the object side at the optical axis, and the image side is flat at the optical axis.

[0155] Combination Figure 1 and Figure 2 The schematic diagram of the optical lens in Embodiment 1 shown, and the main parameters of the optical lens in Embodiment 1 given in Tables 1a to 1d, satisfy the relationship in Table 1b, are obtained through simulation. Figures 3 to 10 The simulation diagram is shown below. Among them, Figures 3 to 6 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at magnification of the optical lens of one embodiment in a conventional viewing position. Figures 7 to 10 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at close magnification using the optical lens in Example 1.

[0156] in, Figure 3 and Figure 7 The horizontal axis of the astigmatism diagram shown represents the vertical position of light of different wavelengths on the image plane of the photosensitive element, in mm; the vertical axis represents the field of view. Figure 4 and Figure 8 The horizontal axis of the distortion graph shown is the distortion value, and the vertical axis is the field of view angle.

[0157] Figure 5 and Figure 9 The horizontal axis of the spherical aberration diagram shown represents the axial position of light of different wavelengths on the image plane of the photosensitive element, in mm; the vertical axis represents the normalized entrance pupil coordinates (note: no unit).

[0158] Figure 6 and Figure 10 The horizontal axis of the magnification chromatic aberration diagram shown represents the vertical position of light of different wavelengths on the image plane of the photosensitive element, and the vertical axis represents the field of view.

[0159] The above descriptions of astigmatism, distortion, spherical aberration, and magnification chromatic aberration are the same as those in other embodiments, and will not be repeated below.

[0160] from Figure 3 It can be seen that the astigmatism value of the optical lens at the normal observation position is controlled between -0.02 and 0.03. Figure 7 As can be seen, the astigmatism value of the optical lens is controlled between -0.05 and 0.03 when viewed at close magnification. Figure 3 and Figure 7 As can be seen, as the field of view increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within ±0.05mm, and the image quality of the optical lens is good.

[0161] from Figure 4 and Figure 8 As can be seen, the distortion of the optical lens gradually increases with the increase of the field of view, but the distortion value can be controlled within 60%, reducing the impact of image distortion on image quality. This indicates that the optical lens has good imaging quality.

[0162] from Figure 5 and Figure 9 As can be seen, the axial values ​​of different wavelengths are controlled within ±0.03mm, and the chromatic difference is good throughout the entire entrance pupil range. Therefore, the on-axis chromatic difference of this optical lens is good.

[0163] from Figure 6 and Figure 10 As can be seen, the vertical chromatic aberration of the system gradually increases with the increase of the field of view, but the chromatic aberration can be controlled within the allowable offset of the diffraction limit, resulting in a smaller chromatic aberration and improved imaging quality.

[0164] In summary, the optical lens shown in Example 1 has a total optical length L of 17.258 mm. During the zoom process, the focal length of the optical lens changes by 0.425 mm, which can achieve the goal of balancing high zoom efficiency and low tolerance sensitivity.

[0165] Figure 11 and Figure 12 A structural diagram of the optical lens of Embodiment 2 is shown. The main differences between the optical lens of Embodiment 2 and the optical lens of Embodiment 1 lie in the parameters of each lens, the relationships they satisfy, the optical power, and the concavity / convexity at the optical axis.

[0166] As an optional embodiment of this application, based on Embodiment 2 of this application, the parameter values ​​of each lens of the optical lens can be referred to Tables 2a to 2d.

[0167] Table 2a

[0168] Face number Surface type R value Thickness (mm) OBJ Standard Infinity 13(1.5) S1 Standard Infinity 0.60 S2 Standard 2.40 0.78 S3 Standard -1.88 1.10 S4 Standard -2.20 0.80 S5 Standard -6.56 2.30 S6 Standard 2.55 0.60 S7 Standard 1.27 0.59 S8 Standard -4.42 0.30 STO Standard Infinity 0.30(1.88) S10 Standard 10.40 0.51 S11 Standard 1.60 0.61 S12 Standard 2.62 2.08(0.50) S13 Standard 11.93 0.99 S14 Standard -3.11 0.26 S15 Standard 3.64 1.40 S16 Standard -4.00 0.67 S17 Standard 15.66 0.24 S18 Standard Infinity 0.40 S19 Standard Infinity 0.60 S20 Standard Infinity 0.60 S21 Standard Infinity 0.01 S22 Standard Infinity 0.4 IMAGE Standard Infinity /

[0169] In Example 2, the total optical length L of the optical lens is 16.139 mm; the F-number at the normal observation position is 7.41, and the focal length f is... w =1.09mm; F-number for close-up magnification observation position =10.0, focal length f =1.39mm.

[0170] The parameters of the optical lens in Example 2 satisfy the relationship shown in Table 2b.

[0171] Table 2b

[0172] parameter <![CDATA[-4.5<f2 / f w <-1.5]]> <![CDATA[-70<f m / f w <-2]]> <![CDATA[-0.7<f1 / f2<-0.3]]> <![CDATA[-2<f2 / f3<-0.5]]> numerical values -3.91 -3.67 -0.47 -1.47

[0173] The positive and negative values ​​of the optical power of each lens in the optical lens of Example 2 are shown in Table 2c.

[0174] Table 2c

[0175]

[0176] The concavity or convexity of the object side or image side of each lens in the optical lens of Example 2 at the optical axis is shown in Table 2d.

[0177] Table 2d

[0178]

[0179] Combination Figure 11 and Figure 12 The schematic diagram of the optical lens in Embodiment 2 shown, and the main parameters of the optical lens in an optional embodiment of Embodiment 2 given in Tables 2a to 2c satisfying the relationship in Table 2b, as well as the concavity and convexity of each lens at the optical axis, were obtained through simulation. Figures 13 to 20 The simulation diagram is shown below. Among them, Figures 13 to 16 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at magnification of the optical lens in Example 2 at a normal viewing position. Figures 17 to 20 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at close magnification using the optical lens in Example 2.

[0180] from Figure 13 It can be seen that the astigmatism value of the optical lens is controlled between -0.02 and 0.06 at the normal observation position. Figure 17 As can be seen, the astigmatism value of the optical lens is controlled between -0.05 and 0.02 when viewed at close magnification. Figure 13 and Figure 17 As can be seen, as the field of view increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within ±0.05mm, and the image quality of the optical lens is good.

[0181] from Figure 14 and Figure 18 As can be seen, the distortion of the optical lens gradually increases with the increase of the field of view, but the distortion value can be controlled within 63%, reducing the impact of image distortion on image quality. This indicates that the optical lens has good imaging quality.

[0182] from Figure 15 and Figure 19 As can be seen, the axial values ​​of different wavelengths are controlled within ±0.07mm, and the chromatic difference is good throughout the entire entrance pupil range. Therefore, the on-axis chromatic difference of this optical lens is good.

[0183] from Figure 16 and Figure 20 As can be seen, the vertical chromatic aberration of the system gradually increases with the increase of the field of view, but the chromatic aberration can be controlled within the allowable offset of the diffraction limit, resulting in a smaller chromatic aberration and improved imaging quality.

[0184] In summary, the optical lens shown in Embodiment 2 has a total optical length L of 16.139 mm. During the zoom process, the focal length of the optical lens changes by 0.3 mm, which can achieve the goal of balancing high zoom efficiency, low tolerance sensitivity, and high image quality.

[0185] Figure 21 and Figure 22 A structural diagram of the optical lens of Embodiment 3 is shown. The main differences between the optical lens of Embodiment 3 and the optical lens of Embodiment 1 lie in the parameters of each lens, the relationships they satisfy, the optical power, and the concavity / convexity at the optical axis.

[0186] As an optional embodiment of this application, based on Embodiment 3 of this application, the parameter values ​​of each lens of the optical lens can be referred to Tables 3a to 3d.

[0187] Table 3a

[0188] Face number Surface R value Thickness (mm) OBJ Standard Infinity 13(1.5) S1 Standard Infinity 0.60 S2 Standard 1.33 1.37 S3 Standard -2.93 0.50 S4 Standard 4.10 0.66 S5 Standard -3.93 1.35 S6 Standard 4.90 0.45 S7 Standard 1.52 0.69 S8 Standard -2.73 0.54 STO Standard Infinity 0.25(1.70) S10 Standard Infinity 0.48 S11 Standard -2.16 0.44 S12 Standard 2.75 1.85(0.40) S13 Standard 12.50 0.91 S14 Standard -3.00 0.23 S15 Standard 3.55 1.10 S16 Standard -3.40 1.11 S17 Standard 27.43 0.34 S18 Standard Infinity 0.40 S19 Standard Infinity 0.72 S20 Standard Infinity 0.60 S21 Standard Infinity 0.01 S22 Standard Infinity 0.4 IMAGE Standard Infinity /

[0189] In Example 3, the total optical length L of the optical lens is 15.035 mm; the F-number at the normal observation position is 6.8, and the focal length f is... w =1.12mm; F-number for close-up magnification observation position =10.0, focal length f =1.50mm.

[0190] The parameters of the optical lens in Example 3 satisfy the relationship shown in Table 3b.

[0191] Table 3b

[0192] parameter <![CDATA[-4.5<f2 / f w <-1.5]]> <![CDATA[-70<f m / f w <-2]]> <![CDATA[-0.7<f1 / f2<-0.3]]> <![CDATA[-2<f2 / f3<-0.5]]> numerical values -2.79 -66.96 -0.52 -1.08

[0193] The positive and negative values ​​of the optical power of each lens in the optical lens of Example 3 are shown in Table 3c.

[0194] Table 3c

[0195]

[0196] The concavity or convexity of the object side or image side of each lens in the optical lens of Embodiment 3 at the optical axis is shown in Table 3d.

[0197] Table 3d

[0198]

[0199] Combination Figure 21 and Figure 22 The schematic diagram of the optical lens in Embodiment 3 shown, and the main parameters of the optical lens in an optional embodiment of Embodiment 3 given in Tables 3a to 3c satisfying the relationship in Table 3b, and the concavity and convexity of each lens at the optical axis, were obtained through simulation. Figures 23 to 30 The simulation diagram is shown below. Among them, Figures 23 to 26 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at magnification of the optical lens in Example 3 at a normal viewing position. Figures 27 to 30 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at close magnification using the optical lens in Example 3.

[0200] from Figure 23 It can be seen that the astigmatism value of the optical lens at a normal observation position is controlled between -0.01 and 0.05. Figure 27 As can be seen, the astigmatism value of the optical lens is controlled between -0.08 and 0.05 when viewed at close magnification. Figure 23 and Figure 27 As can be seen, as the field of view increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within ±0.08mm, and the image quality of the optical lens is good.

[0201] from Figure 24 and Figure 28 As can be seen, the distortion of the optical lens gradually increases with the increase of the field of view, but the distortion value can be controlled within 60%, reducing the impact of image distortion on image quality. This indicates that the optical lens has good imaging quality.

[0202] from Figure 25 and Figure 29 As can be seen, the axial values ​​of different wavelengths are controlled within ±0.09mm, and the chromatic difference is good throughout the entire entrance pupil range. Therefore, the on-axis chromatic difference of this optical lens is good.

[0203] from Figure 26 and Figure 30 As can be seen, the vertical chromatic aberration of the system gradually increases with the increase of the field of view, but the chromatic aberration can be controlled within the allowable offset of the diffraction limit, resulting in a smaller chromatic aberration and improved imaging quality.

[0204] In summary, the total length L of the optical lens shown in Embodiment 3 is 15.035mm. During the zoom process, the focal length of the optical lens changes by 0.38mm, which can achieve the goal of balancing high zoom efficiency, low tolerance sensitivity and high image quality.

[0205] Figure 31 and Figure 32 A structural diagram of the optical lens of Embodiment 4 is shown. The main differences between the optical lens of Embodiment 4 and the optical lens of Embodiment 1 lie in the parameters of each lens, the relationships they satisfy, the optical power, and the concavity / convexity at the optical axis.

[0206] As an optional embodiment of this application, based on Embodiment 4 of this application, the parameter values ​​of each lens of the optical lens can be referred to Tables 4a to 4d.

[0207] Table 4a

[0208] Face number Surface type R value Thickness (mm) OBJ Standard Infinity 13(1.5) S1 Standard Infinity 0.60 S2 Standard 1.40 1.22 S3 Standard -2.72 0.70 S4 Standard 3.90 0.80 S5 Standard -3.90 1.42 S6 Standard 4.96 0.44 S7 Standard 1.60 0.81 S8 Standard -2.87 0.48 STO Standard Infinity 0.24 S10 Standard Infinity 0.67 S11 Standard -2.20 0.42 S12 Standard 3.00 1.64 S13 Standard 13.25 1.05 S14 Standard -2.80 0.06 S15 Standard 3.40 1.21 S16 Standard -3.40 0.80 S17 Standard Infinity 0.23 S18 Standard Infinity 0.40 S19 Standard Infinity 0.72 S20 Standard Infinity 0.60 S21 Standard Infinity 0.01 S22 Standard Infinity 0.4 IMAGE Standard Infinity /

[0209] In Example 4, the total optical length L of the optical lens is 15.513 mm; the F-number at the normal observation position is 6.7, and the focal length f is... w =1.09mm; F-number for close-up magnification observation position =9.9, focal length f =1.45mm.

[0210] The parameters of the optical lens in Example 4 satisfy the relationship shown in Table 4b.

[0211] Table 4b

[0212] parameter <![CDATA[-4.5<f2 / f w <-1.5]]> <![CDATA[-70<f m / f w <-2]]> <![CDATA[-0.7<f1 / f2<-0.3]]> <![CDATA[-2<f2 / f3<-0.5]]> numerical values -2.75 -54.95 -0.54 -1.07

[0213] The positive and negative values ​​of the optical power of each lens in the optical lens of Example 4 are shown in Table 4c.

[0214] Table 4c

[0215]

[0216] The concavity or convexity of the object side or image side of each lens in the optical lens of Embodiment 4 at the optical axis is shown in Table 4d.

[0217] Table 4d

[0218]

[0219] Combination Figure 31 and Figure 32 The schematic diagram of the optical lens in Embodiment 4, and the main parameters of the optical lens in an optional embodiment of Embodiment 4 shown in Tables 4a to 4c satisfying the relationship in Table 4b, as well as the concavity and convexity of each lens at the optical axis, were obtained through simulation. Figures 33 to 40 The simulation diagram is shown below. Among them, Figures 33 to 36 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at magnification of the optical lens in Example 4 at a normal viewing position. Figures 37 to 40 The images shown are astigmatism, distortion, spherical aberration, and chromatic aberration at close magnification using the optical lens in Example 4.

[0220] from Figure 33 It can be seen that the astigmatism value of the optical lens at the normal observation position is controlled between -0.03 and 0.06. Figure 37 As can be seen, the astigmatism value of the optical lens is controlled between -0.015 and 0.0135 when viewed at close magnification. Figure 33 and Figure 37 As can be seen, as the field of view increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within ±0.06mm, and the image quality of the optical lens is good.

[0221] from Figure 34 and Figure 38 As can be seen, the distortion of the optical lens gradually increases with the increase of the field of view, but the distortion value can be controlled within 60%, reducing the impact of image distortion on image quality. This indicates that the optical lens has good imaging quality.

[0222] from Figure 35 and Figure 39 As can be seen, the axial values ​​of different wavelengths are controlled within the range of ±0.042mm, and the chromatic difference is good throughout the entire entrance pupil range. Therefore, the on-axis chromatic difference of this optical lens is good.

[0223] from Figure 36 and Figure 40 As can be seen, the vertical chromatic aberration of the system gradually increases with the increase of the field of view, but the chromatic aberration can be controlled within the allowable offset of the diffraction limit, resulting in a smaller chromatic aberration and improved imaging quality.

[0224] In summary, the total length L of the optical lens shown in Embodiment 4 is 15.513 mm. During the zoom process, the focal length of the optical lens changes by 0.36 mm, which can achieve the goal of balancing high zoom efficiency, low tolerance sensitivity and high image quality.

[0225] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0226] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical lens, characterized in that, It consists of a first lens group, a second lens group, and a third lens group arranged along the object side to the image side. The first lens group and the third lens group both have positive optical power, and the second lens group has negative optical power. The first lens group consists of a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged from the object side to the image side. The first lens and the fourth lens both have negative optical power, and the fifth lens has positive optical power. The second lens group consists of a sixth lens and a seventh lens arranged from the object side to the image side. One of the sixth lens and the seventh lens has positive optical power, and the other has negative optical power. The third lens group consists of an eighth lens, a ninth lens, and a tenth lens arranged from the object side to the image side. The eighth lens and the ninth lens both have positive optical power, and the tenth lens has negative optical power. The second lens group can move relative to the first lens group along the optical axis, so that the optical lens can switch between a normal observation position and a close-up magnified observation position; The combined focal length f of the second lens and the third lens m The focal length f of the optical lens in the normal observation position w Satisfying the relation: -70<f m / f w <-2; The focal length f2 of the second lens group and the focal length f of the optical lens in the normal observation position w Satisfying the relation: -4.5<f2 / f w <-1.5。 2. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens group and the focal length f3 of the third lens group satisfy the following relationship: -2 <f2 / f3<-0.5。 3. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens group and the focal length f2 of the second lens group satisfy the following relationship: -0.7 <f1 / f2<-0.3。 4. The optical lens according to claim 1, characterized in that, The third lens group has a filter on the side closest to the image.

5. The optical lens according to claim 4, characterized in that, The filter is an infrared cutoff filter; Alternatively, the filter may be equipped with a laser cutoff film.

6. A camera module, characterized in that, include: The optical lens according to any one of claims 1 to 5; A photosensitive element is disposed on the image side of the optical lens.

Images