Optical lens and camera module

Abstract

The invention discloses an optical lens and a camera module, the optical lens comprises a first lens group, a second lens group and a third lens group, both the first lens group and the third lens group have positive focal power, the second lens group has negative focal power, and the second lens group can move along an optical axis relative to the first lens group. The optical lens can realize zoom switching between a conventional observation position and a close-range magnification observation position; the first lens group comprises a first lens, a second lens and a third lens, and the focal length fm of the second lens and the third lens and the focal length fw of the optical lens at the conventional observation position meet the relational expression:-70lt; fm / fwlt; -2; the focal length f2 of the second lens group and the focal length fw of the optical lens at the conventional observation position meet the relational expression:-4.5 lt; f < 2 > / f < wlt >; and-1.5. The optical lens can achieve the purposes of high zoom efficiency, low tolerance sensitivity and high image quality in the zoom process.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to an optical lens and a camera module. Background Art

[0002] For professional cameras, different types of optical lenses are often required in different scenarios. For example, in the medical field, in order to accurately diagnose lesions, an optical lens that can be zoomed and focused is required as the endoscope objective lens. The zoom and focus of the optical lens is achieved by moving part of the lens in the optical lens to change the focal length of the optical lens, thereby achieving the requirements of magnified observation from conventional observation to close-range 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 a zoom function that can achieve both high zoom efficiency and high image quality with good aberration correction during the zoom process has become an important issue in the industry. Summary of the invention

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

[0005] In a first aspect, an embodiment of the present application provides an optical lens, comprising a first lens group, a second lens group, and a third lens group arranged from an object side to an image side, wherein the first lens group and the third lens group both have positive optical power, the second lens group has negative optical power, and the second lens group can move relative to the first lens group along an optical axis, so that the optical lens can achieve variable magnification switching between a normal observation position and a close-range magnified observation position; the first lens group comprises a first lens, a second lens, and a third lens arranged from an object side to an image side, and the focal lengths f of the second lens and the third lens are m The focal length f of the optical lens during conventional observation w Satisfies the relationship: -70 <f m / f w <-2; the focal length f2 of the second lens group is equal to the focal length f of the optical lens during normal observation w Satisfies the relationship: -4.5 <f2 / fw<-1.5。

[0006] The beneficial effect of the optical lens provided by the embodiment of the present application is that: by reasonably allocating the optical focal lengths of the first lens group, the second lens group and the third lens group, and simultaneously controlling the ratio of the focal lengths of the second lens and the third lens 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 be switched between the normal observation position and the close-range magnified observation position, which is not only beneficial for balancing the optical focal lengths of the first lens group, the second lens group and the third lens group to reduce aberrations and improve imaging quality, but also, in the process of switching the magnification between normal observation and close-range magnified observation, it is possible to achieve the purpose of having a large depth of field range, high magnification efficiency and low tolerance sensitivity.

[0007] In some embodiments, the first lens group further includes a fourth lens and a fifth lens sequentially arranged on the image side of the third lens from the object side to the image side, 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 arrangement is not only conducive to more flexible allocation of the optical focal length of each lens in the first lens group, so that the optical focal length of the first lens group can be well balanced with the optical focal length of the second lens group and the third lens group, thereby helping to reduce aberrations and improve the imaging quality of the optical lens, but also the first lens group includes five lenses, which is conducive to reducing the total optical length of the optical lens and facilitating the miniaturization design of the optical lens.

[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] Through the above arrangement, the first lens group includes two cemented lenses, which can not only further eliminate the chromatic aberration and spherical aberration of the optical lens; at the same time, the arrangement of multiple groups of cemented lenses not only reduces the tolerance sensitivity and improves the imaging quality of the optical lens, but also reduces the installation process of the optical lens and facilitates the assembly of the optical lens.

[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 relationship: <f2 / f3<-0.5。

[0012] Reasonable distribution of optical power is helpful to balance the aberrations produced by the second lens group and the third lens group, improve the imaging quality, and simplify the structure, which is helpful 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 reasonably distributing the optical focal length and controlling the above 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, reduce the tolerance sensitivity, thereby improving the imaging quality, but also can 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, and the sixth lens and the seventh lens are a cemented lens.

[0016] By designing the sixth lens and the seventh lens as a cemented lens, not only can the travel of the moving lens be reduced to improve the magnification efficiency, but also the tolerance sensitivity of the moving lens during the magnification process can be suppressed; and the movement of the cemented lens will increase the aperture number at the magnified observation position, which is more conducive to increasing the depth of field, so that the focal length adjustment range is small and easier to operate from the conventional observation position to the magnified observation position, without 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, the eighth lens and the ninth lens both have positive optical power, and the tenth lens has negative optical power.

[0018] The above arrangement is not only conducive to more flexible allocation of the optical focal length of each lens in the third lens group, but also enables the optical focal length of the third lens group to be well balanced with the optical focal length of the first lens group and the second lens group, thereby facilitating reduction of aberrations and improving the imaging quality of the optical lens.

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

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

[0021] In some embodiments, a filter is provided on a side of the third lens group close to the image side.

[0022] Through the above arrangement, not only the imaging quality of the optical lens can be improved, but also the application range can be widened.

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

[0024] Through the above-mentioned arrangement, 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 cut-off film.

[0026] Through the above arrangement, the optical lens can be suitable for laser treatment.

[0027] In a second aspect, an embodiment of the present application further provides a camera module, comprising a photosensitive element and the optical lens described in the first aspect, wherein the photosensitive element is arranged on the image side of the optical lens.

[0028] The camera module in the embodiment of the present application has the same technical effect as that achieved by the optical lens in the first aspect, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a structural diagram of the optical lens of Example 1 of the present application in a normal observation position;

[0031] Figure 2 This is a structural diagram of the optical lens of Example 1 of the present application at a close-range magnified observation position;

[0032] Figure 3 This is an astigmatism diagram of the optical lens of Example 1 of the present application at a normal observation position;

[0033] Figure 4 This is a distortion diagram of the optical lens of Example 1 of the present application at a normal observation position;

[0034] Figure 5 This is a spherical aberration diagram of the optical lens of Example 1 of the present application at a normal observation position;

[0035] Figure 6 This is a magnification chromatic aberration diagram of the optical lens of Example 1 of the present application at a normal observation position;

[0036] Figure 7 The astigmatism diagram of the optical lens of Example 1 of the present application when viewed at a close-up magnified observation position;

[0037] Figure 8 This is a distortion diagram of the optical lens of Example 1 of the present application when it is observed at a close distance;

[0038] Fig. 9This is a spherical aberration diagram of the optical lens of Example 1 of the present application when it is at a close-range magnified observation position;

[0039] Fig.10 A magnification chromatic aberration diagram of the optical lens of Example 1 of the present application when viewed at a close-up magnified observation position;

[0040] Fig.11 This is a structural diagram of the optical lens of Example 2 of the present application in a normal observation position;

[0041] Fig.12 This is a structural diagram of the optical lens of the second embodiment of the present application at a close-range magnified observation position;

[0042] Fig.13 This is an astigmatism diagram of the optical lens of Example 2 of the present application at a normal observation position;

[0043] Fig.14 This is a distortion diagram of the optical lens of Example 2 of the present application at a normal observation position;

[0044] Fig.15 This is a spherical aberration diagram of the optical lens of Example 2 of the present application at a normal observation position;

[0045] Fig.16 This is a magnification chromatic aberration diagram of the optical lens of Example 2 of the present application at a normal observation position;

[0046] Fig.17 This is an astigmatism diagram of the optical lens of Example 2 of the present application when it is at a close-range magnified observation position;

[0047] Fig.18 This is a distortion diagram of the optical lens of Example 2 of the present application when it is at a close-range magnified observation position;

[0048] Fig.19 This is a spherical aberration diagram of the optical lens of Example 2 of the present application when it is at a close-range magnified observation position;

[0049] Fig. 20 A magnification chromatic aberration diagram of the optical lens of Example 2 of the present application when viewed at a close-up magnification position;

[0050] Fig.21 This is a structural diagram of the optical lens of Example 3 of the present application in a normal observation position;

[0051] Fig. 22 This is a structural diagram of the optical lens of the third embodiment of the present application at a close-range magnified observation position;

[0052] Fig.23 This is an astigmatism diagram of the optical lens of Example 3 of the present application at a normal observation position;

[0053] Fig.24 This is a distortion diagram of the optical lens of Example 3 of the present application at a normal observation position;

[0054] Fig.25 This is a spherical aberration diagram of the optical lens of Example 3 of the present application at a normal observation position;

[0055] Fig.26 This is a magnification chromatic aberration diagram of the optical lens of Example 3 of the present application at a normal observation position;

[0056] Fig. 27 This is an astigmatism diagram of the optical lens of Example 3 of the present application when it is at a close-range magnified observation position;

[0057] Fig.28 This is a distortion diagram of the optical lens of Example 3 of the present application when it is at a close-range magnified observation position;

[0058] Fig.29 This is a spherical aberration diagram of the optical lens of Example 3 of the present application when it is at a close-range magnified observation position;

[0059] Fig.30 This is a magnification chromatic aberration diagram of the optical lens of Example 3 of the present application when it is at a close-range magnified observation position;

[0060] Fig.31 This is a structural diagram of the optical lens of Example 4 of the present application in a normal observation position;

[0061] Fig.32 This is a structural diagram of the optical lens of the fourth embodiment of the present application at a close-range magnified observation position;

[0062] Fig.33 This is an astigmatism diagram of the optical lens of Example 4 of the present application at a normal observation position;

[0063] Fig.34 This is a distortion diagram of the optical lens of Example 4 of the present application at a normal observation position;

[0064] Fig.35 This is a spherical aberration diagram of the optical lens of Example 4 of the present application at a normal observation position;

[0065] Fig.36 This is a magnification chromatic aberration diagram of the optical lens of Example 4 of the present application at a normal observation position;

[0066] Fig.37 This is an astigmatism diagram of the optical lens of Example 4 of the present application when it is at a close-range magnified observation position;

[0067] Fig.38 This is a distortion diagram of the optical lens of Example 4 of the present application when it is at a close-range magnified observation position;

[0068] Fig.39 This is a spherical aberration diagram of the optical lens of Example 4 of the present application when it is at a close-range magnified observation position;

[0069] Fig.40 This is a diagram of the chromatic aberration of the optical lens of Example 4 of the present application when it is observed at a close distance.

[0070] Among them, the reference numerals in the figure are:

[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 DESCRIPTION

[0072] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are explained and described below.

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

[0074] A lens or lens group with positive optical power has a positive focal length and has 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 the convergence or divergence of light in an optical lens. It refers to the vertical distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through the lens or lens group. For a fixed-focus lens, the position of its optical center is fixed; for a telephoto lens, the change of the optical center of the lens brings about a change in the focal length of the lens.

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

[0078] The total optical length TTL (Total Track Length) refers to the distance from the center of the lens to the focus of light gathering, that is, in the module, the distance from the center of the lens to the imaging plane of the sensor surface.

[0079] The object side is bounded by the lens. The side where the object is located is called the object side, and the surface of the lens close to the object side is called the object side.

[0080] The image side is bounded by the lens. The side where the image of the object is located is called the image side, and the surface of the lens close to the image side is called the image side.

[0081] The aperture (aperture diaphragm) is a device used to control the amount of light that passes through the lens and enters the photosensitive surface inside the camera body. It is usually inside the lens.

[0082] Aperture number, also known as F number (FNO), is a relative value obtained by dividing the focal length of the lens by the diameter of the lens entrance pupil (the inverse of the relative aperture). The smaller the aperture value, the more light enters in the same unit time. The larger the aperture value, the smaller the depth of field, and the background content of the photo will be blurred, similar to the effect of a telephoto lens.

[0083] Total track length (TTL) refers to the total length from the surface of the lens closest to the object side to the imaging surface. TTL is the main factor affecting the height of the camera.

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

[0085] The optical axis is an axis that passes vertically through the center of the lens. The optical axis of the lens is the axis that passes through the center of each lens of the lens.

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

[0087] Aberration: An optical lens has the properties of an ideal optical system at the optical axis. The near-axis light emitted from a point on the object intersects the image plane at one point (also known as the optical axis image point). However, the light rays that actually pass through the lens with different apertures are difficult to intersect perfectly at one point, but have a certain deviation from the position of the near-axis image point. These differences are collectively called aberrations.

[0088] Spherical aberration, generally speaking, when light from a spherical lens enters the lens and reaches the focal plane, it is more likely to be severely refracted and bent at the edge than at the center. This phenomenon will lead to a decrease in sharpness and contrast, and the generation of light spots, which will reduce image quality. The larger the aperture, the more serious it is. Therefore, this situation can be improved by closing the aperture, but it cannot be completely eliminated. This aberration caused by a spherical lens is called spherical aberration.

[0089] Distortion, also known as distortion, is the degree of distortion of the image formed by an optical lens relative to the object itself. Distortion is due to the influence of aperture spherical aberration. The height of the intersection of the main light of different fields of view with the Gaussian image plane after passing through the optical lens is not equal to the ideal image height. The difference between the two is the distortion.

[0090] Astigmatism, because the object point is not on the optical axis of the optical lens, the light beam it emits has an inclination angle with the optical axis. After the light beam is refracted by the lens, the convergence point of its meridional beamlet and sagittal beamlet is not at the same point. That is, the light beam cannot be focused on one point, and the image is not clear, so astigmatism occurs. Meridian beamlet and sagittal beamlet are the names of light beams in two vertical planes in a rotationally symmetric optical lens.

[0091] Meridian plane: The plane formed by the chief ray (chief light beam) of an object point outside the optical axis and the optical axis is called the meridian plane.

[0092] Sagittal plane: The plane that passes through the main ray (main light beam) of the object point outside the optical axis and is perpendicular to the meridian plane is called the sagittal plane.

[0093] Field curvature is used to indicate the difference between the clearest image point position of the non-central field of view light after passing through the optical lens group and the clearest image point position of the central field of view on the optical axis. When the lens has field curvature, the intersection point of the entire light beam does not coincide with the ideal image point. Although a clear image point can be obtained at each specific point, the entire image plane is a curved surface.

[0094] Chromatic aberration of magnification is a type of chromatic aberration caused by the difference in image size due to the different heights (i.e. magnification) of images of different colors of light.

[0095] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0096] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0097] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0098] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" 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 accurately diagnose lesions, an optical lens that can be zoomed and focused is required as the endoscope objective lens. The zoom and focus of the optical lens is achieved by moving some lenses in the optical lens to change the focal length of the optical lens, thereby achieving the requirements of magnified observation position from the normal observation position to the 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 a zoom function that can achieve high zoom efficiency, low tolerance sensitivity and high image quality with good aberration correction during the zoom process has become an important issue in the industry.

[0101] In order to solve the above technical problems, an embodiment of the present application provides an optical lens, including a first lens group, an aperture, a second lens group and a third lens group arranged from the object side to the image side. By reasonably allocating the optical power of the first lens group, the second lens group and the third lens group, and controlling the ratio of the focal length of the second lens and the third lens in the first lens group to the focal length of the optical lens at the conventional observation position, and the ratio of the focal length of the second lens group to the focal length of the optical lens at the conventional observation position, the optical lens can be switched between the conventional observation position and the close-range magnification observation position. This is not only conducive to balancing the optical power of the first lens group, the second lens group and the third lens group to reduce aberrations and improve imaging quality, but also, in the process of switching between the conventional observation position and the close-range magnification observation position, it is possible to achieve the purpose of high magnification efficiency, low tolerance sensitivity and high image quality.

[0102] The present application embodiment provides a camera module, including: Figure 1 , Fig.11 , Fig.21 and Fig.31The optical lens and the sensing element shown in the figure, the sensing element is arranged on the image side of the optical lens (such as Figure 1 far right shown).

[0103] The above-mentioned photosensitive element can be a CCD (Charge coupled Device) image sensor or a CMOS image sensor. In some embodiments, in order to protect the photosensitive element and to facilitate the placement of the photosensitive element, the photosensitive element and the protective glass plate L13 are fixed together for arrangement. Furthermore, in order to improve the imaging quality of the optical lens, a positioning glass plate L12 is usually arranged on the protective glass plate L13 close to the object side of the optical lens. In this way, the photosensitive element can be positioned by adjusting the relative position between the protective glass plate L13 and the positioning glass plate L12, thereby improving the installation accuracy of the photosensitive element, which is beneficial to improving the imaging quality of the optical lens.

[0104] The camera module can be used on an electronic device with a camera function. The electronic device can be an endoscope with a camera function. Of course, the electronic device can be other electronic devices with a camera function in addition to an endoscope with a camera function, which is not specifically limited here.

[0105] like Figure 1 and Figure 2 As shown, the embodiment of the present 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 focal lengths, the second lens group G2 has negative focal lengths, and the second lens group G2 can move along the optical axis relative to the first lens group G1, so that the optical lens can be realized in a conventional observation position (such as Figure 1 The position shown) and the close-up magnification observation position (as shown Figure 2 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, and the focal lengths f of the second lens L2 and the third lens L3 are m The focal length f of the optical lens in the normal observation position w Satisfies the relationship: -70 <f m / f w <-2; the focal length f2 of the second lens group G2 is equal to the focal length f of the optical lens in the normal observation position w Satisfies the relationship: -4.5 <f2 / f w <-1.5.

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

[0107] For example, the second lens group G2 in the optical lens of the first embodiment can be moved 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 be moved between the first lens group G1 and the third lens group G3, that is, in the embodiment Figure 1 and Figure 2 The two positions shown are moved relative to the first lens group G1, so as to achieve variable magnification and focusing between the normal observation position and the close-range magnified observation position. Of course, variable magnification and focusing can also be achieved by moving some lenses in the second lens group G2, or by relatively moving at least two of the first lens group G1, the second lens group G2, and the third lens group G3, which is not specifically limited here.

[0108] Among them, f m / f w and f2 / f w These are two important parameters in the design process of optical lenses, which directly affect the zoom efficiency, tolerance sensitivity, and radial space occupied by the optical lens, i.e., the aperture. If the above parameters are small, the focal length of the optical lens will be reduced, and the chromatic aberration of magnification will be over-corrected and the tolerance sensitivity will be poor during the zoom and focus adjustment process, and the imaging quality of the optical lens cannot be guaranteed; if the above parameters are large, the focal length of the optical lens will be increased, and insufficient correction will occur during the zoom and focus adjustment process, the imaging quality will be reduced, and the aperture of the first lens L1 in the first lens group G1 will also increase, which cannot meet the application occasions of small aperture and high image quality.

[0109] The optical lens provided in the embodiment of the present application reasonably distributes the optical power of the first lens group G1, the second lens group G2 and the third lens group G3, which is beneficial to balancing the optical power of the first lens group G1, the second lens group G2 and the third lens group G3, so as to reduce aberrations and improve imaging quality; at the same time, by controlling the ratio of the focal length of the second lens and the third lens 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 the magnification between the normal observation position and the close-range magnification observation position, so that in the process of switching the magnification between the normal observation position and the close-range magnification observation position, the purpose of taking into account high magnification efficiency, low tolerance sensitivity and high image quality can be achieved.

[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 which are sequentially arranged on the image side of the third lens L3 from the object side to the image side. That is, the first lens group G1 includes the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 which are arranged from the object side to the image side, the first lens L1 and the fourth lens L4 both have negative refractive power, the second lens L2 and the third lens L3 both have refractive power, and the fifth lens L5 has positive refractive power.

[0111] By reasonably allocating the optical power of the five lenses in the first lens group G1, the optical power and focal length selection combination of each lens in the first lens group G1 is made more flexible, so that the optical power of the first lens group G1 can be better balanced with the optical power of the second lens group G2 and the third lens group G3, which is beneficial to reducing aberrations and improving the imaging quality of the optical lens. In addition, the five lenses in the first lens group G1 are beneficial to reducing the total optical length of the optical lens, which is beneficial to the miniaturized design of the optical lens, thereby enabling the optical lens to achieve the purpose of taking both high image quality and miniaturization into consideration.

[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 connected by a cementing process to form a cemented lens, and the fourth lens L4 and the fifth lens L5 can be connected by a cementing process to form a cemented lens.

[0113] Through the above arrangement, the first lens group G1 includes two cemented lenses, that is, the number of cemented lenses in the first lens group G1 is maximized, so that not only can the chromatic aberration and spherical aberration of the optical lens be further eliminated; at the same time, the arrangement of multiple groups of cemented lenses not only reduces the tolerance sensitivity, but also increases the incident angle to produce more high-order aberrations, thereby better offsetting the primary aberrations to achieve aberration balance, thereby improving the imaging quality of the optical lens, and the arrangement of multiple cemented lenses reduces the installation process of the optical lens and facilitates the assembly of the optical lens.

[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 them, f1 / f2 is an important parameter in the design process of the optical lens, and the above parameters are related to the aperture of the optical lens, that is, the radial occupied space of the optical lens and the imaging quality. If the above parameters are small, not only will the refractive power of the first lens group G1 become weaker, thereby increasing the aperture of the optical lens and failing to achieve small-aperture application scenarios, but also the aberration of the optical lens cannot be well corrected, resulting in poor imaging quality of the optical lens; if the above parameters are large, the focal length of the first lens group G1 is large, although the aperture of the optical lens can be reduced, but at the same time the optical lens will produce large aberrations, the image quality will be seriously reduced, and the tolerance sensitivity is also poor.

[0116] By reasonably distributing the optical focal length and controlling the above ratio within the above range, it is not only beneficial to balance the aberrations generated by the first lens group G1 and the second lens group G2, reduce the tolerance sensitivity, and thus improve the imaging quality, but also beneficial to the miniaturization design of the optical lens, especially for small-aperture application scenarios, 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 relationship: <f2 / f3<-0.5。

[0118] Among them, f2 / f3 is an important parameter in the design process of the optical lens. If the above parameters are small, the refractive power of the third lens group G3 becomes stronger, which is not conducive to the correction of the aberration of the optical lens, thereby affecting the image quality; if the above parameters are large, the refractive power of the third lens group G3 becomes weaker, the back focal length of the optical lens will become larger, and the total optical length of the optical lens will be longer, which is not conducive to the miniaturization design of the optical lens.

[0119] By reasonably distributing the optical power and controlling the above ratio within the above range, it is not only beneficial to balance the aberrations produced by the second lens group G2 and the third lens group G3 and improve the imaging quality, but also simplifies the structure and reduces the total optical length of the optical lens, which is beneficial to 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, and the sixth lens L6 and the seventh lens L7 are a cemented lens.

[0121] Since the second lens group G2 can move along the optical axis according to the change of the object distance to adjust the focus position of the image plane, by designing the sixth lens L6 and the seventh lens L7 as a cemented lens, it is not only possible to reduce the stroke of the second lens group G2 and improve the magnification efficiency, but also suppress the tolerance sensitivity of the second lens group G2 in the magnification process; and the movement of the cemented lens will increase the aperture number at the magnified observation position, which is more conducive to increasing the depth of field, so that the focal length adjustment range is small and easier to operate in the process from the conventional observation position to the magnified observation position, without the need for frequent focusing. In addition, it is conducive to further eliminating chromatic aberration and spherical aberration, so that the optical lens can achieve the purpose of high magnification efficiency, low tolerance sensitivity, miniaturization and easy 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 refractive power, and the tenth lens L10 has negative refractive power.

[0123] The above arrangement is conducive to more flexible allocation of the optical power of each lens in the third lens group G3, so that the optical power of the third lens group G3 can be well balanced with the optical power of the first lens group G2 and the second lens group G2, reducing aberrations, thereby improving the imaging quality of the optical lens; and it is conducive to reducing the total optical length of the optical lens, thereby facilitating the miniaturization design of the optical lens.

[0124] In some embodiments, the ninth lens L9 and the tenth lens L10 are cemented lenses, which is not only conducive to further eliminating the chromatic aberration and spherical aberration of the optical lens, but also reduces the installation process of the optical lens and facilitates the assembly of the optical lens.

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

[0126] Through the above arrangement, the optical lens can have the function of cutting into and out of the optical path of a certain filter L11 in the optical path, that is, the function of the filter L11 blocking light and not blocking light is realized, thereby diversifying the functions of the optical lens, not only improving the imaging quality in specific application scenarios, but also allowing different filters L11 to be selected according to different application scenarios, and having a wide range of applications. For example, the optical path of the cold light source of a medical endoscope can change the bandwidth of a certain monochromatic light in the optical path without replacing the light-emitting component, thereby realizing the need to select the illumination working mode of light sources with different wavelengths.

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

[0128] Through the above arrangement, 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.

[0129] The above-mentioned infrared cut-off film is the abbreviation of infrared cut-off filter (also called infrared filter or heat-absorbing filter), which is a filter used to filter infrared bands. For example, when installed on equipment with incandescent lamps (such as slides, 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 rays 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 providing a laser cut-off film on the filter L11, the optical lens can be suitable for laser treatment.

[0132] The laser cutoff film may be a functional film such as a YAG laser cutoff film or a LD laser cutoff film. The laser cutoff film may be provided on one side of the filter L11 or on both sides of the filter L11, which is not specifically limited here.

[0133] like Figure 1 and Figure 2 The structure of the optical lens in the first embodiment is shown. The optical lens comprises a first lens group G1, a stop STO, a second lens group G2 and a third lens group G3 arranged from the object side to the image side. That is, the optical lens comprises Figure 1 As shown, the first lens group G1, the aperture 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 a cemented lens, and the fourth lens L4 and the fifth lens L5 are a cemented lens; 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 a cemented lens; 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 a cemented lens, and a filter L11 is further provided on the side of the tenth lens L10 away from the ninth lens L9.

[0134] As an optional embodiment of the present application, based on the first embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 1a to Table 1d.

[0135] Table 1a

[0136] Surface 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" is the number of each surface arranged from the object side to the image side, "Standard" in the surface type represents a standard spherical surface, and the radius R value is the lens with the corresponding surface number, that is, the radius of curvature of the object side or image side of the lens corresponding to each surface number at the optical axis. The "infinity" in the "radius of curvature" parameter series of the lens means that the object side or image side of the lens is a plane; the last "IMAGE" in the "Surface Number" in the table refers to the image side of the optical lens. Since the optical lens of the present application can be zoomed and focused, "OBJ" refers to the object plane, and the two values ​​inside and outside the brackets of "OBJ" in the "Thickness" parameter series refer to two different object distances of the optical lens. The first value of each lens in the "Thickness / Spacing" parameter series is the thickness of the lens on the optical axis, and the second value is the distance from the image side of the lens to the object side of the next lens on the optical axis; the value of the aperture STO in the "Thickness" parameter series is the distance from the center of the aperture STO to the object side of the next lens on the optical axis. For example, Figure 1 As shown, in the optical lens of this embodiment, when the object distance is 13mm, the distance between the aperture 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 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 from the object side surface of the first lens L1 to the protective glass plate L13, that is, the imaging surface of the optical lens, and between the adjacent object side surface, image side surface, and aperture STO. For example, the value of “S1” in the “Thickness” parameter column represents the distance between the object side surface and the image side surface of the first lens L1, the value of “S2” in the “Thickness” parameter column represents the distance between the image side surface of the first lens L1 and the object side surface of the second lens L2, the value of “S8” in the “Thickness” parameter column represents the distance between the image side surface of the fifth lens L5 and the aperture STO, and the value of “S12” in the “Thickness” parameter column represents the distance between the image side surface of the seventh lens L7 and the object side surface of the eighth lens L8. The values ​​inside and outside the brackets correspond to the corresponding object distances.

[0138] In the embodiment of the present application, the total optical length L of the optical lens is 17.258 mm; the F number at the normal observation position is 6.32, and the focal length f w =0.933mm; F ​​number at close magnified 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]]> Numeric -2.48 -17.63 -0.53 -0.85

[0142] Note: The following are the explanations of the relationship between the optical lenses in each embodiment:

[0143] f w It is the focal length of the optical lens at the normal observation position, which 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 lengths of all lenses in the first lens group G1;

[0145] f2 is the focal length of the second lens group G2, that is, the focal lengths of the sixth lens L6 and the seventh lens L7;

[0146] f m is the focal length of the second lens L2 and the third lens L3;

[0147] The positive and negative conditions of the focal length of each lens in the optical lens of 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 conditions of the focal length of each lens in the optical lens in Example 1. Among them, "+" represents that the lens has a positive focal length; "-" represents that the lens has a negative focal length.

[0151] The concave-convex condition of the object side surface or image side surface of each lens in the optical lens of Example 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 concave and convex conditions of the object side or image side of each lens at the optical axis. Among them, "++" represents that both the object side and the image side of the lens are convex toward the object at the optical axis; "+-" represents that the object side of the lens is convex toward the object at the optical axis, and the image side is convex toward the object at the optical axis, that is, a double convex crescent structure; "-+" represents that the object side of the lens is concave toward the object at the optical axis, and the image side is convex toward the object at the optical axis, that is, a double concave structure; "∞+-" represents that the object side of the lens is flat at the optical axis, and the image side is convex toward the object at the optical axis; "+∞" represents that the object side of the lens is convex toward the object at the optical axis, and the image side is flat at the optical axis; "--' represents that both the object side and the image side of the lens are concave toward the object at the optical axis; "∞-" represents that the object side of the lens is flat at the optical axis, and the image side is concave toward the object at the optical axis; "-∞" represents that the object side of the lens is concave toward the object at the optical axis, and the image side is flat at the optical axis.

[0155] Combination Figure 1 and Figure 2 The structural diagram of the optical lens in the first embodiment shown in FIG. 1 and the main parameters of the optical lens in the first embodiment given in Tables 1a to 1d satisfy the relationship in Table 1b. The simulation results show that Figures 3 to 10 The simulation diagram shown. Figures 3 to 6 The astigmatism diagram, distortion diagram, spherical aberration diagram and magnification chromatic aberration diagram of the optical lens of the first embodiment at the normal observation position are respectively shown; Figures 7 to 10 The astigmatism diagram, distortion diagram, spherical aberration diagram and chromatic aberration diagram of the optical lens in the first embodiment at a close-up magnified observation position are respectively shown.

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

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

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

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

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

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

[0162] from Figure 5 and Fig. 9 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.03mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0163] from Figure 6 and Fig.10 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the system gradually increases, but the vertical axis chromatic aberration can be controlled within the deviation allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0164] In summary, the total optical length L of the optical lens shown in Example 1 is 17.258 mm. During the zooming process, the focal length of the optical lens changes by 0.425 mm, which can achieve the purpose of both high zooming efficiency and low tolerance sensitivity.

[0165] Fig.11 and Fig.12 The structure of the optical lens of the second embodiment is shown. The main differences between the structure of the optical lens of the second embodiment and the optical lens of the first embodiment are the parameters of each lens, the relationship they satisfy, the focal power, and the concave-convex condition at the optical axis.

[0166] As an optional embodiment of the present application, based on the second embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 2a to Table 2d.

[0167] Table 2a

[0168] Surface 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 Standaard -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 the second embodiment, the total optical length of the optical lens L = 16.139 mm; the F number at the normal observation position = 7.41, and the focal length f w =1.09mm; F ​​number at close magnified 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]]> Numeric -3.91 -3.67 -0.47 -1.47

[0173] The positive and negative conditions of the focal length of each lens in the optical lens of Example 2 are shown in Table 2c.

[0174] Table 2c

[0175]

[0176] The concave-convex condition of the object side surface or image side surface 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 Fig.11 and Fig.12 The structural diagram of the optical lens in the second embodiment shown in the figure, and the main parameters of the optical lens of an optional embodiment in the second embodiment given in Tables 2a to 2c satisfy the relationship in Table 2b, and the concave-convex condition of each lens at the optical axis, are obtained through simulation. Figures 13 to 20 The simulation diagram shown. Figures 13 to 16 The astigmatism diagram, distortion diagram, spherical aberration diagram and magnification chromatic aberration diagram of the optical lens in the second embodiment at the normal observation position are shown respectively; Figures 17 to 20 The astigmatism diagram, distortion diagram, spherical aberration diagram and chromatic aberration diagram of the optical lens in the second embodiment at a close-up magnified observation position are respectively shown.

[0180] from Fig.13 It can be seen that the astigmatism value of the optical lens in the conventional observation position is controlled between -0.02 and 0.06. Fig.17 It can be seen that the astigmatism value of the optical lens is controlled between -0.05 and 0.02 when the optical lens is in the close-up magnified observation position. Fig.13 and Fig.17 It can be seen that as the field of view angle increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within the range of ±0.05mm, and the image quality of the optical lens is good.

[0181] from Fig.14 and Fig.18 It can be seen that as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within 63%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0182] from Fig.15 and Fig.19 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.07mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0183] from Fig.16 and Fig. 20 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the system gradually increases, but the vertical axis chromatic aberration can be controlled within the deviation allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0184] In summary, the total optical length L of the optical lens shown in Example 2 is 16.139 mm. During the zooming process, the focal length of the optical lens changes by 0.3 mm, which can achieve the goals of high zooming efficiency, low tolerance sensitivity and high image quality.

[0185] Fig.21 and Fig. 22 The structure of the optical lens of the third embodiment is shown. The structure of the optical lens of the third embodiment is different from that of the optical lens of the first embodiment mainly in the parameters of each lens, the relationship they satisfy, the focal power, and the concave-convex condition at the optical axis.

[0186] As an optional embodiment of the present application, on the basis of Embodiment 3 of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 3a to Table 3d.

[0187] Table 3a

[0188] Surface number Surface Class 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 the third embodiment, the total optical length of the optical lens L = 15.035 mm; the F number at the normal observation position = 6.8, and the focal length f w =1.12mm; F ​​number at close magnified 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]]> Numeric -2.79 -66.96 -0.52 -1.08

[0193] The positive and negative conditions of the focal length of each lens in the optical lens of Example 3 are shown in Table 3c.

[0194] Table 3c

[0195]

[0196] The concave-convex condition of the object side surface or image side surface of each lens in the optical lens of Example 3 at the optical axis is shown in Table 3d.

[0197] Table 3d

[0198]

[0199] Combination Fig.21 and Fig. 22 The structural schematic diagram of the optical lens in the third embodiment shown in the figure, and the main parameters of the optical lens of an optional embodiment in the third embodiment given in Tables 3a to 3c satisfy the relationship in Table 3b, and the concave-convex condition of each lens at the optical axis, are obtained through simulation. Figures 23 to 30 The simulation diagram shown. Figure 23 to Figure 26 The astigmatism diagram, distortion diagram, spherical aberration diagram and magnification chromatic aberration diagram of the optical lens in the third embodiment at the normal observation position are shown respectively; Figures 27 to 30 The astigmatism diagram, distortion diagram, spherical aberration diagram and chromatic aberration diagram of the optical lens in the third embodiment at a close-up magnified observation position are respectively shown.

[0200] from Fig.23 It can be seen that the astigmatism value of the optical lens in the conventional observation position is controlled between -0.01 and 0.05. Fig. 27 It can be seen that the astigmatism value of the optical lens is controlled between -0.08 and 0.05 when the optical lens is in the close-up magnified observation position. Fig.23 and Fig. 27 It can be seen that as the field of view angle increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within the range of ±0.08mm, and the image quality of the optical lens is good.

[0201] from Fig.24 and Fig.28 It can be seen that as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within 60%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0202] from Fig.25 and Fig.29 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.09mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0203] from Fig.26 and Fig.30 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the system gradually increases, but the vertical axis chromatic aberration can be controlled within the deviation allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

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

[0205] Fig.31 and Fig.32 The structure of the optical lens of the fourth embodiment is shown. The main differences between the structure of the optical lens of the fourth embodiment and the optical lens of the first embodiment are the parameters of each lens, the relationship they satisfy, the focal power, and the concave-convex condition at the optical axis.

[0206] As an optional embodiment of the present application, on the basis of Embodiment 4 of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 4a to Table 4d.

[0207] Table 4a

[0208] Surface 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 the fourth embodiment, the total optical length of the optical lens L = 15.513 mm; the F number at the normal observation position = 6.7, and the focal length f w =1.09mm; F ​​number at close magnified 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]]> Numeric -2.75 -54.95 -0.54 -1.07

[0213] The positive and negative conditions of the focal length of each lens in the optical lens of Example 4 are shown in Table 4c.

[0214] Table 4c

[0215]

[0216] The concave-convex condition of the object side surface or image side surface of each lens in the optical lens of Example 4 at the optical axis is shown in Table 4d.

[0217] Table 4d

[0218]

[0219] Combination Fig.31 and Fig.32 The structural diagram of the optical lens in the fourth embodiment shown in the figure, and the main parameters of the optical lens of an optional embodiment in the fourth embodiment given in Tables 4a to 4c satisfy the relationship in Table 4b, and the concave-convex condition of each lens at the optical axis, are obtained through simulation. Figures 33 to 40 The simulation diagram shown. Figure 33 to Figure 36 The astigmatism diagram, distortion diagram, spherical aberration diagram and magnification chromatic aberration diagram of the optical lens in the fourth embodiment at the normal observation position are shown respectively; Figures 37 to 40 The astigmatism diagram, distortion diagram, spherical aberration diagram and chromatic aberration diagram of the optical lens in the fourth embodiment are shown respectively when the optical lens is at a close-range magnified observation position.

[0220] from Fig.33 It can be seen that the astigmatism value of the optical lens in the conventional observation position is controlled between -0.03 and 0.06. Fig.37 It can be seen that the astigmatism value of the optical lens is controlled between -0.015 and 0.0135 when it is in the close-up magnified observation position. Fig.33 and Fig.37 It can be seen that as the field of view angle increases, the astigmatism of the system gradually increases, but the astigmatism value can be controlled within the range of ±0.06mm, and the image quality of the optical lens is good.

[0221] from Fig.34 and Fig.38 It can be seen that as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within 60%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0222] from Fig.35 and Fig.39 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.042mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0223] from Fig.36 and Fig.40 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the system gradually increases, but the vertical axis chromatic aberration can be controlled within the deviation allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0224] In summary, the total length L of the optical lens shown in Example 4 is 15.513 mm. During the zooming process, the focal length of the optical lens changes by 0.36 mm, which can achieve the goals of high zooming 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 an appropriate manner in any one or more embodiments or examples.

[0226] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An optical lens, characterized in that: The optical lens comprises 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, the second lens group has negative optical power, and the second lens group can move along the optical axis relative to the first lens group, so that the optical lens can be switched between a normal observation position and a close-range magnification observation position for variable magnification; 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 lengths of the second lens and the third lens are f m The focal length f of the optical lens in the normal observation position w Satisfies the relationship: -70<f m / f w <-2; The focal length f2 of the second lens group is equal to the focal length f2 of the optical lens in the normal observation position. w Satisfies the relationship: -4.5<f2 / f w <-1.5。 2. The optical lens according to claim 1, characterized in that: The first lens group further includes a fourth lens and a fifth lens which are sequentially arranged on the image side of the third lens from the object side to the image side, the first lens and the fourth lens both have negative optical power, the second lens and the third lens both have optical power, and the fifth lens has positive optical power.

3. The optical lens according to claim 2, characterized in that: The second lens and the third lens are a cemented lens, and the fourth lens and the fifth lens are a cemented lens.

4. The optical lens according to any one of claims 1 to 3, characterized in that: The focal length f2 of the second lens group and the focal length f3 of the third lens group satisfy the relationship: -2 <f2 / f3<-0.5。 5. The optical lens according to any one of claims 1 to 3, characterized in that: 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。 6. The optical lens according to any one of claims 1 to 3, characterized in that: The second lens group includes a sixth lens and a seventh lens arranged from the object side to the image side, and the sixth lens and the seventh lens are cemented lenses.

7. The optical lens according to claim 6, characterized in that: The third lens group includes 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 refractive power, and the tenth lens has negative refractive power.

8. The optical lens according to claim 7, characterized in that: The ninth lens and the tenth lens are cemented lenses.

9. The optical lens according to claim 8, characterized in that: A filter is provided on a side of the third lens group close to the image side.

10. The optical lens according to claim 9, characterized in that: The filter is an infrared cutoff filter; Alternatively, the optical filter is provided with a laser cut-off film.

11. A camera module, characterized in that: include: The optical lens according to any one of claims 1 to 10; A photosensitive element is arranged on the image side of the optical lens.

Images