Optical lens, camera module, endoscope and endoscope system

Abstract

The utility model provides an optical lens, a camera module, an endoscope and an endoscope system.The optical lens comprises a plurality of lenses and a diaphragm, and the number of the lenses is at least six; the optical lens comprises a first glued lens and a second glued lens, the first glued lens is formed by two or three lenses, the second glued lens is formed by two or three lenses, and the diaphragm is located between the first glued lens and the second glued lens; the total optical length L of the optical lens and the focal length f of the optical lens meet the relational expression: 6.50 lt; l / flt; and 11.00. The optical lens can achieve the purposes of high resolution, wide field angle and high image quality.

Description

Technical Field

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

[0002] Camera modules, such as endoscope objectives, are usually used in conjunction with endoscopes to transmit images detected by the endoscope to detectors for better observation. They are commonly used in modern medical minimally invasive surgery and gastrointestinal examination and treatment.

[0003] To accurately diagnose lesions, endoscopes are expected to have excellent imaging quality, enabling doctors to better identify lesions and improve diagnostic efficiency. They are also expected to have a wider field of view and higher resolution, thereby increasing the doctor's observation range and shortening examination time. Developing an optical lens that combines high resolution, high image quality, and miniaturization has become a key issue in the industry. Utility Model Content

[0004] Embodiments of the present application provide an optical lens, a camera module, an endoscope, and an endoscope system with high resolution, high image quality, and miniaturization.

[0005] In a first aspect, an embodiment of the present application provides an optical lens. The optical lens includes a plurality of lenses and an aperture, wherein the number of the lenses is at least six; the optical lens includes a first cemented lens and a second cemented lens, wherein the first cemented lens is formed by two or three of the lenses, and the second cemented lens is formed by two or three of the lenses, and the aperture is located between the first cemented lens and the second cemented lens; the total optical length L of the optical lens and the focal length F of the optical lens satisfy the relationship: 6.50 <L / F<11.00。

[0006] The optical lens provided by the embodiment of the present application has the following beneficial effects: by arranging the aperture between the first cemented lens and the second cemented lens, it is not only beneficial to control the angle range of light entering the aperture, thereby facilitating the expansion of the angular range of the field of view; it is also beneficial to correct aberrations, thereby improving imaging quality; and it is also beneficial to simplify the assembly process of the optical lens. In addition, by rationally selecting the total optical length and focal length of the optical lens so that the ratio of the total optical length to the focal length satisfies the above-mentioned relationship, it is beneficial to achieve both high resolution and high image quality and miniaturization of the optical lens.

[0007] In some embodiments, among the multiple lenses, the number of the lenses with negative optical power is at least two, and the number of the lenses with positive optical power is at least two. Among them, the lens with negative optical power is a negative lens, and the lens with positive optical power is a positive lens; the first cemented lens is composed of one negative lens and one positive lens, so that the first cemented lens has positive optical power; the second cemented lens is composed of one negative lens and one positive lens, so that the second cemented lens has positive optical power.

[0008] With the above settings, not only is the tolerance sensitivity of the optical lens better, which is beneficial to improving the resolution and imaging quality of the optical lens, but also the assembly of the optical lens is convenient.

[0009] In some embodiments, in the first cemented lens, the refractive index Ndx of the negative lens and the refractive index Ndy of the positive lens satisfy the relational expression: -0.60 < Ndx - Ndy < -0.15; the Abbe number Vdx of the negative lens and the Abbe number Vdy of the positive lens satisfy the relational expression: -20 < Vdx - Vdy < 65.

[0010] With the above settings, the imaging quality of the optical lens is greatly improved.

[0011] In some embodiments, in the second cemented lens, the refractive index Ndm of the negative lens and the refractive index Ndn of the positive lens satisfy the relational expression: -0.60 < Ndm - Ndn < -0.15; the Abbe number Vdm of the negative lens and the Abbe number Vdn of the positive lens satisfy the relational expression: -20 < Vdm - Vdn < 65.

[0012] With the above settings, the imaging quality of the optical lens is further improved.

[0013] In some embodiments, the number of the lenses is six, and the aperture stop is located between the third lens and the fifth lens arranged from the object side to the image side.

[0014] With the above settings, not only is the structure of the optical lens symmetrical, but it is also beneficial to balance the imaging quality and the aperture size.

[0015] In some embodiments, the aperture stop is located between the third lens and the fourth lens arranged from the object side to the image side.

[0016] With the above settings, the structure of the optical lens is further made symmetrical, and it is also beneficial to balance the imaging quality and the aperture size.

[0017] In some embodiments, the second lens and the third lens arranged from the object side to the image side form the first cemented lens, and the fifth lens and the sixth lens arranged from the object side to the image side form the second cemented lens.

[0018] Through the above-mentioned setting, the light passing through the optical lens is made smoother, the tolerance sensitivity is reduced, and the imaging quality is further improved.

[0019] In some embodiments, the first lens arranged from the object side to the image side is the negative lens, and the fourth lens arranged from the object side to the image side is the positive lens.

[0020] Through the above setting, by reasonably allocating the optical power of the optical lens, not only the aberration is reduced, thereby further improving the imaging quality, but also the light passes through the aperture at a smaller angle, which is conducive to reducing the aperture of the optical lens.

[0021] In a second aspect, an embodiment of the present application further provides an optical lens comprising a plurality of lenses, an aperture and an optical element, wherein the number of the lenses is at least 6; the optical lens comprises a first cemented lens and a second cemented lens, wherein the first cemented lens is formed by 2 or 3 of the lenses, and the second cemented lens is formed by 2 or 3 of the lenses; along the direction from the object side to the image side, the first cemented lens, the aperture, the second cemented lens and the optical element are arranged in sequence; along the direction from the object side to the image side, the total optical length of the optical lens and the back focal length BFL of the optical lens satisfy the relationship: 3≤L / BFL≤4.5.

[0022] The optical lens provided by the embodiment of the present application has the following beneficial effects: by arranging the aperture between the first cemented lens and the second cemented lens, it is not only beneficial to control the angle range of light entering the aperture, thereby facilitating the expansion of the angular range of the field of view; it is also beneficial to correct aberrations, thereby improving imaging quality; at the same time, it is beneficial to simplify the assembly process of the optical lens; in addition, by reasonably selecting the total optical length of the optical lens and the back focal length of the optical lens so that the ratio of the total optical length to the back focal length satisfies the above-mentioned relationship, it is beneficial to achieve a balance between high resolution, high image quality, and the total length of the optical lens.

[0023] In some embodiments, the total optical length L of the optical lens and the focal length F of the optical lens satisfy the relationship:

[0024] 6.50 <L / F<11.00。

[0025] By reasonably selecting the total optical length L and the focal length F of the optical lens so that the ratio of the two satisfies the above relationship, it is helpful to further take into account the total length and imaging quality of the optical lens.

[0026] In some embodiments, along the direction from the object side to the image side, the distance T between the lens at the last position in the second cemented lens and the optical element is: 0.5 mm < T < 1.8 mm.

[0027] Through the above arrangement, the design efficiency of the optical lens is improved.

[0028] In some embodiments, a thickness t of the optical element along the optical axis of the optical lens is 0.3 mm ≤ t ≤ 1 mm.

[0029] The above arrangement is conducive to the miniaturization and lightweight design of the optical lens.

[0030] In some embodiments, a thickness t of the optical element along the optical axis of the optical lens is 0.65 mm.

[0031] The above arrangement is further conducive to the miniaturization and lightweight design of the optical lens.

[0032] In some embodiments, the optical element is a filter.

[0033] Through the above arrangement, not only the imaging quality of the optical lens can be improved, but also the application range can be widened.

[0034] In some embodiments, the filter is an infrared cutoff filter.

[0035] Through the above-mentioned setting, 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.

[0036] In some embodiments, the filter is provided with a laser cutoff film.

[0037] Through the above arrangement, the optical lens can be suitable for laser treatment.

[0038] In some embodiments, the optical element is a prism.

[0039] In a third aspect, an embodiment of the present application further provides a camera module, comprising the optical lens and photosensitive element described in the first or second aspect above, wherein the photosensitive element is arranged on the image side of the optical lens.

[0040] 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 or the second aspect, and will not be repeated here.

[0041] In some embodiments, a protective sheet is provided on the photosensitive element.

[0042] Through the above arrangement, the photosensitive element can be well protected.

[0043] In a fourth aspect, an embodiment of the present application further provides an endoscope comprising the camera module described in the third aspect above.

[0044] The endoscope in the embodiment of the present application achieves the same technical effects as the camera module in the third aspect, which will not be repeated here.

[0045] In a fifth aspect, an embodiment of the present application further provides an endoscope system, comprising a display, a light source host, an image processing device, and the endoscope described in the fourth aspect above.

[0046] The camera module in the embodiment of the present application has the same technical effect as that achieved by the endoscope in the fourth aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0048] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present application;

[0049] Figure 2 This is a light path diagram of the optical lens in Example 1 of the present application;

[0050] Figure 3 This is a diagram of the magnification spherical aberration of the optical lens in Example 1 of the present application;

[0051] Figure 4 spherical aberration diagram of the optical lens in Example 1 of the present application;

[0052] Figure 5 This is an astigmatism diagram of the optical lens in Example 1 of the present application;

[0053] Figure 6 This is a distortion diagram of the optical lens in Example 1 of the present application;

[0054] Figure 7 This is a schematic structural diagram of the optical lens in Example 2 of the present application;

[0055] Figure 8 This is a diagram of the magnification spherical aberration of the optical lens in Example 2 of the present application;

[0056] Figure 9 This is a spherical aberration diagram of the optical lens in Example 2 of the present application;

[0057] Figure 10This is an astigmatism diagram of the optical lens in Example 2 of the present application;

[0058] Figure 11 This is a distortion diagram of the optical lens in Example 2 of the present application;

[0059] Figure 12 This is a schematic structural diagram of the optical lens in Example 3 of the present application;

[0060] Figure 13 This is a diagram of the magnification spherical aberration of the optical lens in Example 3 of the present application;

[0061] Figure 14 This is a spherical aberration diagram of the optical lens in Example 3 of the present application;

[0062] Figure 15 This is an astigmatism diagram of the optical lens in Example 3 of the present application;

[0063] Figure 16 This is a distortion diagram of the optical lens in Example 3 of the present application;

[0064] Figure 17 This is a schematic structural diagram of the optical lens in Example 4 of the present application;

[0065] Figure 18 This is a diagram of the magnification spherical aberration of the optical lens in Example 4 of the present application;

[0066] Figure 19 This is a spherical aberration diagram of the optical lens in Example 4 of the present application;

[0067] Figure 20 This is an astigmatism diagram of the optical lens in Example 4 of the present application;

[0068] Figure 21 This is a distortion diagram of the optical lens in Example 4 of the present application;

[0069] Figure 22 This is a schematic structural diagram of the optical lens in Example 5 of the present application;

[0070] Figure 23 This is a diagram of the magnification spherical aberration of the optical lens in Example 5 of the present application;

[0071] Figure 24 This is a spherical aberration diagram of the optical lens in Example 5 of the present application;

[0072] Figure 25 This is an astigmatism diagram of the optical lens in Example 5 of the present application;

[0073] Figure 26 This is a distortion diagram of the optical lens in Example 5 of the present application;

[0074] Figure 27 Schematic diagram of the structure of the optical lens in Example 6 of the present application;

[0075] Figure 28 This is a diagram of the magnification spherical aberration of the optical lens in Example 6 of the present application;

[0076] Figure 29 This is a diagram of the spherical aberration of the optical lens in Example 6 of the present application;

[0077] Figure 30 This is an astigmatism diagram of the optical lens in Example 6 of the present application;

[0078] Figure 31 This is a distortion diagram of the optical lens in Example 6 of the present application.

[0079] Among them, the reference numerals in the figures are:

[0080] First cemented lens G1; second cemented lens G2; first lens L1; second lens L2; ​​third lens L3; fourth lens L4; fifth lens L5; sixth lens L6; optical element L7; protective sheet L8; aperture stop STO. DETAILED DESCRIPTION

[0081] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of this application are explained and described below.

[0082] 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.

[0083] A lens or lens group with positive optical power has a positive focal length and has the effect of converging light.

[0084] A lens or lens group with negative optical power has a negative focal length and has the effect of diverging light.

[0085] Focal length (F), also known as focal length, is a measure of light convergence or divergence in optical lenses. It refers to the vertical distance from the optical center of a lens or lens group to the focal plane, when an object at infinite distance forms a sharp image through the lens or lens group. From a practical perspective, it can be understood as the distance from the lens center to the plane when the object is at infinite distance. For fixed-focus lenses, the position of the optical center is fixed; for zoom lenses, changes in the optical center result in changes in the lens' focal length.

[0086] Back focal length FBL is the length from the rear end of the optical lens to the imaging surface.

[0087] Total Track Length (TTL) refers to the distance from the center of the lens to the focal point of light collection. In other words, in the module, it refers to the distance from the center of the lens to the imaging plane on the sensor surface.

[0088] The object side is divided 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.

[0089] The image side, with the lens as the boundary, 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.

[0090] The aperture (aperture diaphragm) is a device used to control the amount of light passing through the lens and entering the photosensitive surface inside the camera body. It is usually inside the lens.

[0091] Aperture number, also known as F-number (FNO), is a relative value calculated by dividing the focal length of a lens by the diameter of its entrance pupil (the inverse of the relative aperture). The smaller the aperture, the more light enters per unit time. A larger aperture reduces the depth of field, blurring the background in photos, similar to the effect of a telephoto lens.

[0092] 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.

[0093] 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.

[0094] The optical axis is an axis running perpendicularly through the center of a lens. It's the axis running through the centers of each lens element. When light rays parallel to the optical axis enter a convex lens, an ideal convex lens would have all the rays converge at a single point behind the lens. This point is the focal point.

[0095] Focus is the point where parallel light rays converge after being refracted by a lens or group of lenses.

[0096] 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 a point (also known as the optical axis image point). However, the light rays that actually pass through the lens with different apertures are unlikely to intersect perfectly at a point, but instead have a certain deviation from the position of the near-axis image point. These differences are collectively called aberrations.

[0097] Spherical aberration. When light rays enter a spherical lens and reach the focal plane, they are more likely to bend and refract more severely at the edges than at the center. This phenomenon reduces sharpness and contrast, creates flare, and degrades image quality. It becomes more severe with larger apertures. While stopping down the aperture can improve this problem, it cannot be completely eliminated. This aberration caused by spherical lenses is called spherical aberration.

[0098] Distortion, also known as distortion, refers to the degree to which the image formed by an optical lens is distorted relative to the object itself. Distortion is caused by spherical aberration. The height at which the chief rays of light from different fields of view intersect 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. Therefore, distortion only changes the image position of off-axis object points on the ideal plane, distorting the image shape but not affecting image clarity.

[0099] Astigmatism occurs when the object point is not on the optical axis of an optical lens. The resulting beam is tilted at an angle to the optical axis. After refraction through the lens, the convergence points of the meridional and sagittal beamlets are not aligned. This means the beam cannot be focused to a single point, resulting in an unclear image. This is known as astigmatism. Meridional and sagittal beamlets are the names for beams in two perpendicular planes within a rotationally symmetric optical lens.

[0100] Meridian plane: The plane formed by the chief ray (chief beam) of an object point outside the optical axis and the optical axis is called the meridian plane.

[0101] The sagittal plane is the plane that passes through the main ray (main beam) of the object point outside the optical axis and is perpendicular to the meridian plane.

[0102] Field curvature describes the difference in the optical axis between the sharpest image point of non-central field rays and the sharpest image point of the central field rays after passing through an optical lens system. When a lens exhibits field curvature, the intersection of the entire light 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.

[0103] 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.

[0104] A laminated lens, also known as a cemented lens, is a composite lens composed of two or more lenses cemented together. Compared to single lenses, laminated lenses have better tolerance sensitivity. When used in endoscopes, they facilitate lens assembly and improve endoscope imaging quality.

[0105] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0106] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0107] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", and "connect" 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.

[0108] 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 the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0109] Camera modules, such as endoscope objectives, are usually used in conjunction with endoscopes to transmit images detected by the endoscope to detectors for better observation. They are commonly used in modern medical minimally invasive surgery and gastrointestinal examination and treatment.

[0110] To accurately diagnose lesions, endoscopes are expected to have excellent imaging quality, enabling doctors to better identify lesions and improve diagnostic efficiency. They are also expected to have a wide field of view, increasing the doctor's observation range and shortening examination time. Developing an optical lens with high resolution, a wide field of view, and high image quality has become a key issue in the industry.

[0111] To address the aforementioned technical issues, embodiments of the present application provide an optical lens and camera module. The optical lens comprises at least six lenses arranged from the object side to the image side and an aperture stop STO. A portion of the lenses form a first cemented lens G1 and a second cemented lens G2, with the aperture stop STO positioned between the first cemented lens G1 and the second cemented lens G2. By rationally designing the ratio of the optical lens's total optical length L to its focal length F, it is advantageous to achieve a balance between high resolution, a wide field of view, high image quality, and the overall length of the optical lens.

[0112] like Figure 1 As shown, in some embodiments, the camera module includes an optical lens and a photosensitive element, and the photosensitive element is located on the image side of the optical lens (located on the image side of the optical lens). Figure 1 (Image side view in IMAGE).

[0113] The working principle of the camera module is as follows: the light reflected by the photographed scene generates an optical image through the optical lens and is projected onto the photosensitive surface of the photosensitive element. The photosensitive element converts the optical image into an electrical signal, namely an analog image signal, and transmits it to the processor.

[0114] Among them, the photosensitive element (also known as an image sensor) is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When exposed to light, it generates an electric charge. The photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). CCD is made of a highly sensitive semiconductor material that can convert light into electric charge. A charge coupled device is composed of many photosensitive units, usually measured in millions of pixels. When the surface of the photosensitive element is exposed to light, each photosensitive unit will reflect the charge on the component. The signals generated by all the photosensitive units are added together to form a complete picture.

[0115] Among them, the optical lens mainly uses the refraction principle of the lens to form an image, that is, the light of the scene passes through the optical lens, forming a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element located on the focal plane.

[0116] The camera module can be used in electronic devices with video and photo recording capabilities. For example, the camera module can function as an endoscope with a camera function, with the optical lens serving as the objective lens of the endoscope. Of course, the electronic device can also be other electronic devices with a camera function, in addition to an endoscope with a camera function, and this is not specifically limited here.

[0117] like Figure 1 and Figure 2As shown, the optical lens includes multiple lenses and a stop STO, and the number of lenses is at least 6; the optical lens includes a first cemented lens G1 and a second cemented lens G2, the first cemented lens G1 is formed by two or three of the above lenses, and the second cemented lens G2 is formed by two or three of the above lenses, and the stop STO is located between the first cemented lens G1 and the second cemented lens G2; the total optical length L of the optical lens and the focal length F of the optical lens satisfy the relationship: 6.50 <L / F<11.00。

[0118] The first cemented lens G1 and the second cemented lens G2 are formed by cementing two or three lenses.

[0119] By setting the aperture STO between the first cemented lens G1 and the second cemented lens G2, it is not only beneficial to control the angle range of light entering the aperture STO, thereby helping to expand the field of view angle range and improve resolution; it is also beneficial to correct aberrations, thereby improving imaging quality. At the same time, the setting of two cemented lenses is beneficial to simplifying the assembly process of the optical lens.

[0120] The ratio of an optical lens's total optical length to its focal length is a crucial parameter for its optics. If this ratio is too small, the overall length of the lens will be reduced, facilitating miniaturization. However, this will make it difficult to correct aberrations, resulting in lower resolution and poor imaging quality. If this ratio is too large, while it facilitates wide field of view and high resolution, it will also make the overall length of the lens excessively long, hindering miniaturization. This is especially true for optical lenses used in endoscopes, where the aperture and overall length are typically relatively small, placing high demands on the lens' size.

[0121] By reasonably selecting the total optical length L and focal length F of the optical lens, the ratio of the total optical length L to the focal length F satisfies the above relationship. This is conducive to achieving a balance between high resolution, wide field of view, high image quality and the total length of the optical lens.

[0122] like Figure 1 As shown, in some embodiments, among the multiple lenses, there are at least two lenses with negative focal power and at least two lenses with positive focal power, wherein the lens with negative focal power is a negative lens and the lens with positive focal power is a positive lens; the first cemented lens G1 is composed of one negative lens ( Figure 1 The third lens L3 of the optical lens) and a positive lens ( Figure 1 The second lens L2 of the optical lens is composed of a negative lens ( Figure 1 The sixth lens L6 of the optical lens) and a positive lens ( Figure 1It consists of the fifth lens L5 of the optical lens, so that the second cemented lens G2 has a positive optical power.

[0123] Both the first cemented lens G1 and the second cemented lens G2 are composed of one positive lens and one negative lens. In this way, when the optical performance of the optical lens body meets the requirements, it is beneficial to simplify the manufacturing process, facilitate assembly, and reduce costs. Moreover, both the first cemented lens G1 and the second cemented lens G2 have positive optical powers and have the effect of converging light. In this way, when the light passes through the first cemented lens G1, the aperture stop STO, and the second cemented lens G2 of the optical lens, the light is relatively gentle and the tolerance sensitivity is good, which is beneficial to improving the resolution and imaging quality of the optical lens.

[0124] Of course, the positions of the positive lens and the negative lens in the first cemented lens G1 and the second cemented lens G2 can also be interchanged. For example, in Figure 7 the optical lens, the negative lens of the first cemented lens G1 is the second lens L2, and the positive lens is the third lens Lc, which is not specifically limited here.

[0125] As Figure 1 shown, in some embodiments, in the first cemented lens G1, the refractive index Ndx of the negative lens ( Figure 1 the third lens L3 of the optical lens) and the refractive index Ndy of the positive lens ( Figure 1 the second lens L2 of the optical lens) satisfy the relationship: -0.60 < Ndx - Ndy < -0.15; the Abbe number Vdx of the negative lens and the Abbe number Vdy of the positive lens satisfy the relationship: -20 < Vdx - Vdy < 65.

[0126] The refractive index and Abbe number of the optical lens are very important for improving the optical performance of the optical lens. Especially, the different position combinations of the positive lens and the negative lens in the cemented lens, and the different values of the corresponding refractive index and Abbe number are particularly important for the optical performance of the optical lens.

[0127] If the difference between the refractive index Ndx of the negative lens and the refractive index Ndy of the positive lens in the first cemented lens G1 is too large or too small, or the difference between the Abbe number Vdx of the negative lens and the Abbe number Vdy of the positive lens is too large or too small, it will make it difficult to correct the axial chromatic aberration and lateral chromatic aberration of the optical lens, resulting in a reduction in the imaging quality of the optical lens.

[0128] By reasonably selecting the refractive index and Abbe number of the positive lens and the negative lens in the first cemented lens G1, it is not only beneficial to the correction of axial chromatic aberration and lateral chromatic aberration, but also balances the lenses before and after the first cemented lens G, such as Figure 1 the aberration generated by the first lens L1 receiving light in, thus greatly improving the imaging quality of the optical lens.

[0129] As shown Figure 1 in some embodiments, in the second cemented lens G2, for the negative lens (the sixth lens L6 of the optical lens in Figure 1 ), the refractive index Ndm of the negative lens and the refractive index Ndn of the positive lens (the fifth lens L5 of the optical lens in Figure 1 ) satisfy the relationship: -0.60 < Ndm - Ndn < -0.15; the Abbe number Vdm of the negative lens and the Abbe number Vdn of the positive lens satisfy the relationship: -20 < Vdm - Vdn < 65.

[0130] If the difference between the refractive index Ndm of the negative lens and the refractive index Ndn of the positive lens in the second cemented lens G2 is too large or too small, or if the difference between the Abbe number Vdm of the negative lens and the Abbe number Vdn of the positive lens is too large or too small, it will be very difficult to correct the axial chromatic aberration and lateral chromatic aberration of the optical lens, resulting in a reduction in the imaging quality of the optical lens.

[0131] By reasonably selecting the refractive index and Abbe number of the positive lens and negative lens in the second cemented lens G2, it is not only beneficial to the correction of axial chromatic aberration and lateral chromatic aberration, but also balances the lenses before and after the second cemented lens G2. For example Figure 1 the aberration generated by the fourth lens L4 receiving light in further improves the imaging quality of the optical lens.

[0132] In some embodiments, the number of lenses is 6, and the aperture stop STO is located between the 3rd lens and the 5th lens arranged from the object side to the image side.

[0133] If the aperture stop STO is too close to the object side, although it is beneficial to reduce the aperture of the optical lens body, it increases the difficulty of correcting aberration and the imaging quality is relatively large; if the aperture stop STO is too close to the image side, although it can well correct aberration and improve the imaging quality, it will cause the aperture of the optical lens to be relatively large and the applicable range is limited, for example, it cannot be adapted to an endoscope.

[0134] By setting the aperture stop STO between the 3rd lens and the 5th lens arranged from the object side to the image side, in this way, it is equivalent to the aperture stop STO being located near the middle position of the 6 lenses, which not only makes the structure of the optical lens symmetric, but also is beneficial to taking into account both the imaging quality and the aperture size.

[0135] In some embodiments, the aperture stop STO is located between the 3rd lens and the 4th lens arranged from the object side to the image side.

[0136] By setting the aperture stop STO between the 3rd lens and the 4th lens arranged from the object side to the image side, in this way, it is equivalent to the aperture stop STO being located at the middle position of multiple lenses, which not only further improves the symmetry of the structure of the optical lens, but also further is beneficial to taking into account both the imaging quality and the aperture size.

[0137] In some embodiments, the second lens and the third lens arranged from the object side to the image side form a first cemented lens G1, and the fifth lens and the sixth lens arranged from the object side to the image side form a second cemented lens G2.

[0138] Through the above-mentioned setting, the light passing through the optical lens is made smoother, the tolerance sensitivity is reduced, and the imaging quality is further improved.

[0139] In some embodiments, the first lens arranged from the object side to the image side is a negative lens, and the fourth lens arranged from the object side to the image side is a positive lens.

[0140] Through the above arrangement, after the light passes through the first lens of the optical lens, it first diverges and then converges through the first cemented lens G1 before passing through the aperture STO, which is beneficial for reducing the aperture of the aperture STO. The light then enters the fourth lens and the second cemented lens G2 in sequence, where it further converges. This not only reduces the aperture of the optical lens, thereby facilitating a miniaturized design of the optical lens, but also effectively corrects the aberrations of the optical lens by rationally allocating the optical power of the optical lens, thereby further improving the imaging quality.

[0141] like Figure 1 As shown, an embodiment of the present application further provides an optical lens, comprising a plurality of lenses, a stop STO and optical elements, wherein the number of lenses is at least 6; the optical lens comprises a first cemented lens G1 and a second cemented lens G2, wherein the first cemented lens G1 is formed by 2 or 3 lenses, and the second cemented lens G2 is formed by 2 or 3 lenses; along the direction from the object side to the image side, the first cemented lens G1, the stop STO, the second cemented lens G2 and the optical element L7 are arranged in sequence; along the direction from the object side to the image side, the total optical length L of the optical lens and the back focal length BFL of the optical lens satisfy the relationship: 3<L / BFL<5.

[0142] In the design process of optical lenses, how to improve resolution and image quality while also balancing miniaturization is a challenge. On the one hand, this can be achieved by rationally selecting the total optical length (L) and the focal length (F) of the optical lens, so that the ratio of the total optical length (L) to the focal length (F) of the optical lens satisfies a certain relationship, thereby achieving the goals of high resolution, high image quality, and miniaturization. On the other hand, researchers have found that the ratio of the total optical length (L) to the back focal length (BFL) is also a very important parameter in the design process of optical lenses. The size of this ratio will directly affect the resolution, image quality, and total optical length of the optical lens.

[0143] If the above ratio is too small, the back focal length BFL of the optical lens will decrease, which is beneficial to miniaturization. However, it makes it difficult to correct the aberration of the optical lens, resulting in a lower resolution and a poorer imaging quality. If the above ratio is too large, although it is beneficial to achieve high resolution, it will cause the total length of the optical lens to be too long, which is not conducive to the miniaturization of the optical lens. In particular, it cannot be applied to scenarios with a small installation space such as endoscopes. By reasonably selecting the ratio of the total optical length L to the back focal length BFL to satisfy the above relational expression, and at the same time, setting the aperture stop STO between the first cemented lens G1 and the second cemented lens G2, in this way, it is not only beneficial to control the angular range of light entering the aperture stop STO, thereby being beneficial to expanding the angular range of the field of view and improving the resolution; moreover, it is beneficial to correct the aberration, thereby improving the imaging quality, so that the optical lens achieves the purpose of兼顾 high resolution, high imaging quality and miniaturization.

[0144] In some embodiments, the total optical length L of the optical lens and the focal length F of the optical lens satisfy the relational expression: 6.50 < L / F < 11.00. The beneficial effects of the optical lens in this embodiment refer to the above embodiments and will not be elaborated here.

[0145] In some embodiments, along the direction from the object side to the image side, the distance T between the lens at the last position in the second cemented lens G2 (i.e., the sixth lens L6 in the optical lens) and the optical element L7 is: 0.5mm < T < 1.8mm. Figure 1

[0146] In the process of selecting the value of the back focal length BFL of the optical lens, the distance T between the lens at the last position in the optical lens and the optical element L7 is the main changing factor. By setting the above distance T within the above range, when the back focal length BFL is the same, it is convenient to determine the thickness of the optical element L7 and improves the design efficiency of the optical lens.

[0147] In some embodiments, the thickness t of the optical element along the optical axis of the optical lens is 0.3mm ≤ t ≤ 1mm.

[0148] Through the above settings, the weight of the optical lens is reduced, which is beneficial to the miniaturization and lightweight design of the optical lens.

[0149] In some embodiments, the thickness t of the optical element L7 along the optical axis of the optical lens is 0.65mm.

[0150] Through the above settings, it is further beneficial to the miniaturization and lightweight design of the optical lens and improves the design efficiency.

[0151] Figure 1 As shown, in some embodiments, the optical element is a filter.

[0152] Optical elements are filters. By placing filters within an optical lens, the lens can function as a filter in or out of the optical path, effectively blocking or not blocking light. This diversifies the functionality of the optical lens, improving imaging quality in specific applications and allowing for the selection of filters based on the specific application, broadening its application range. For example, the cold light source optical path of a medical endoscope can be modified by changing the bandwidth of a monochromatic light source within the optical path without replacing the light-emitting component, thereby enabling the selection of illumination modes with light sources of different wavelengths.

[0153] In some embodiments, the filter is an infrared cutoff filter.

[0154] Through the above-mentioned setting, 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.

[0155] The IR cutoff filter (also called an infrared filter or heat-absorbing filter) is a filter used to filter infrared wavelengths. For example, it can be installed on devices using incandescent lamps (such as slides and projectors) to prevent unnecessary heat from burning the lens. It can also be installed on cameras using solid-state electronic devices (CCD or CMOS image sensors) to prevent infrared rays from passing through the camera lens and causing image distortion.

[0156] In some embodiments, the filter is provided with a laser cutoff film (not shown in the figure).

[0157] By setting a laser cut-off film on the filter, the optical lens can be suitable for laser treatment.

[0158] The laser cutoff film may be a functional film such as a YAG laser cutoff film or an LD laser cutoff film. The laser cutoff film may be provided on one side of the filter or on both sides of the filter, and is not specifically limited here.

[0159] Of course, the optical element can be a prism in addition to a filter, so as to meet different application scenarios.

[0160] like Figure 1 As shown, in some embodiments, a protective sheet L8 is provided on the photosensitive element, that is, the protective sheet L8 is located between the photosensitive element and the optical element L7.

[0161] By providing the protective sheet L8 on the photosensitive element, it can not only play a bearing role and facilitate installation, but also well protect the photosensitive element, which is conducive to improving the reliability of the photosensitive element.

[0162] like Figure 1 and Figure 2The structure of the optical lens in the first embodiment of the present application 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. In other words, 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 (as shown in FIG. Figure 1 The lens (shown in the figure, arranged from left to right) comprises a first lens L1, a second lens L2, a third lens L3, an aperture stop STO, a fourth lens L4, a fifth lens L5, and a sixth lens L6. The second lens L2 and the third lens L3 form a first cemented lens G1, and the fifth lens L5 and the sixth lens L6 form a second cemented lens G2. The first cemented lens G1 has positive refractive power, and the second cemented lens G2 has positive refractive power. Specifically, the refractive power of each lens is shown in Table 1b below. An optical element L7 and a protective sheet L8 are also provided on the image side of the sixth lens L6.

[0163] 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.

[0164] Table 1a

[0165] Surface number Surface type R-value Thickness (mm) Refractive index Abbe number OBJ Standard Infinity 10 S1 Standard Infinity 0.600 1.83 42.0 S2 Standard 0.85 0.406 S3 Standard -11.00 0.816 2.00 27.3 S4 Standard -1.60 0.600 1.82 35.0 S5 Standard -7.30 0.344 STO Standard Infinity 0.219 S7 Standard Infinity 0.725 1.47 85.0 S8 Standard -1.20 1.026 S9 Standard 2.55 1.162 1.57 71.3 S10 Standard -1.63 0.450 1.78 25.7 S11 Standard -7.50 1.192 S12 Standard Infinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 1.52 64.2 IMAGE Standard Infinity /

[0166] 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 "curvature radius" parameter column 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 column refer to two different object distances of the optical lens. The first value of each lens in the "thickness / spacing" parameter column 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 column is the distance from the center of the aperture STO to the object side of the next lens on the optical axis. The values ​​"S1" through "S11" in the "Thickness" column represent the distances from the object-side surface of first lens element L1 to the adjacent object-side surface, image-side surface, and aperture stop STO of optical element L7. The value "S12" in the "Thickness" column represents the thickness of optical element L7, and the value "S13" in the "Thickness" column represents the thickness of protective sheet L8.

[0167] In the embodiment of the present application, the total optical length L of the optical lens is 8.54 mm; the focal length F is 1.08 mm; the image height is 1.20 mm; and the field of view angle is 160°.

[0168] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 1b.

[0169] Table 1b

[0170]

[0171] It should be noted that the "+" and "-" in Table 1b represent the positive and negative optical power of each lens in the optical lens of Example 1. Among them, "+" represents that the lens has positive optical power; "-" represents that the lens has negative optical power.

[0172] 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 1c.

[0173] Table 1c

[0174]

[0175] It should be noted that the "∞+," "--," "∞-," and "+-" in Table 1d represent the concave-convexity of the object-side or image-side surface of each lens at the optical axis. "∞+" indicates that the object-side surface of the lens is flat at the optical axis, and the image-side surface is convex toward the object at the optical axis; "--" indicates that both the object-side and image-side surfaces of the lens are concave toward the object at the optical axis; "∞-" indicates that the object-side surface of the lens is flat at the optical axis, and the image-side surface is concave toward the object at the optical axis; and "+-" indicates that both the object-side surface and the image-side surface of the lens are convex toward the object at the optical axis, i.e., a double-convex crescent structure. Of course, in addition to those shown in the table, the concave and convex situations also include "++", "-+", "+∞", "-∞", etc., among which "++" means that both the object side and the image side of the lens are convex toward the object at the optical axis; "-+" means 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; "+∞" means 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; "-∞" means 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.

[0176] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 1d.

[0177] Table 1d

[0178] parameter L / F L / BFL T Numerical 7.91 3.90 1.517 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.18 7.70 0.21 -45.60

[0179] Note: The following are explanations of the relationship between the optical lenses in each embodiment:

[0180] F is the focal length of the optical lens, which is equal to the EFL value of the optical lens.

[0181] BFL is the back focal length of the optical lens, from the object side to the image side, located between the last lens of the optical lens and the image side ( Figure 1 The distance between IMAGE) in Figure 1 The distance BFL between the sixth lens L6 and the image-side surface in the first embodiment is equal to the sum of the thickness values ​​of S11, S12, and S13 in Table 1a.

[0182] T is the direction from the object side to the image side, and the last lens in the second cemented lens G2 ( Figure 1 The distance between the sixth lens L6 and the optical element L7 shown in the figure is the same as the distance between the sixth lens L6 and the optical element L7 in Example 1, where T is equal to the value of S11 at the thickness in Table 1a plus half of the value of S11 at the thickness.

[0183] Ndx is the refractive index of the negative lens in the first cemented lens G1; for example, the refractive index of the third lens L3 in this embodiment is 1.82.

[0184] Ndy is the refractive index of the positive lens in the first cemented lens G1; for example, the refractive index of the second lens L2 in this embodiment is 2.00; Ndx-Ndy=1.82-2=-0.18.

[0185] Vdx is the Abbe number of the negative lens in the first cemented lens G1; for example, the Abbe number of the third lens L3 in this embodiment is 35.0.

[0186] Vdy is the Abbe number of the positive lens in the first cemented lens G1; for example, the Abbe number of the second lens L2 in this embodiment is 27.3.

[0187] Vdx-Vdy=35.0-27.3=7.70.

[0188] Ndm is the refractive index of the negative lens in the second cemented lens G2; for example, the refractive index of the sixth lens L6 in this embodiment is 1.78.

[0189] Ndn is the refractive index of the positive lens in the second cemented lens G2; for example, the refractive index of the fifth lens L5 in the embodiment is 1.57; Ndm-Ndn=1.78-1.57=0.21.

[0190] Vdm is the Abbe number of the negative lens in the second cemented lens G2; for example, the Abbe number of the sixth lens L6 in the embodiment is 25.7.

[0191] Vdn is the Abbe number of the positive lens in the second cemented lens G2; for example, the Abbe number of the fifth lens L5 in the embodiment is 71.3; Vdm-Vdn=25.7-71.3=-45.60.

[0192] The lenses corresponding to the above parameters Ndx, Ndy, Vdx, Vdy, Ndm, Ndn, Vdm and Vdn are determined according to the positions of the positive lens and the negative lens in the first cemented lens G1 and the second cemented lens G2 in different embodiments and are not specifically limited here.

[0193] Combine Figure 1 and Figure 2 The structural diagram and optical path diagram of the optical lens in the embodiment 1 shown in FIG. 1 and the main parameters of the optical lens in the embodiment 1 given in Tables 1a to 1c satisfy the relationship in Table 1d. The simulation results show that Figures 3 to 6 The simulation diagram shown. Figures 3 to 6 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 1.

[0194] in, Figure 3 In the magnification spherical aberration diagram shown, the horizontal axis 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.

[0195] Figure 4 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).

[0196] Figure 5 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.

[0197] Figure 6 In the distortion diagram shown, the horizontal axis is the distortion value, and the vertical axis is the field of view angle.

[0198] The above descriptions of the magnification spherical aberration diagram, spherical aberration diagram, astigmatism diagram, and distortion diagram are the same as those in other embodiments and will not be repeated hereafter.

[0199] from Figure 3 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0200] from Figure 4It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.05mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0201] from Figure 5 It can be seen that the astigmatism value of the optical lens is controlled between -0.01 and 0.06. 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.

[0202] from Figure 6 As can be seen from the figure, as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within the range of 80%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0203] In summary, the image height of the optical lens shown in Example 1 is 1.20 mm, indicating that the resolution of the optical lens is relatively high; the field of view is 160°, which can be applied to colonoscopy; and Figure 3-Figure 6 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0204] Figure 7 The structure of the optical lens of Example 2 is shown. The main differences between the structure of the optical lens of Example 2 and the optical lens of Example 1 are the parameters of each lens, the relationship they satisfy, the optical power, and the concave-convex condition at the optical axis.

[0205] 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.

[0206] In the embodiment of the present application, the total optical length L of the optical lens is 8.33 mm; the focal length F is 1.19 mm; the image height is 1.22 mm; and the field of view angle is 160°.

[0207] Table 2a

[0208] Surface number Surface type R-value Thickness (mm) Refractive index Abbe number OBJ Standard Infinity 13 S1 Standard Infinity 0.600 1.88 40.8 S2 Standard 0.89 0.395 S3 Standard -18.85 0.60 1.69 43.7 S4 Standard 2.45 0.776 2.00 25.3 S5 Standard -8.81 0.380 STO Standard Infinity 0.217 S7 Standard Infrinity 0.693 1.46 90.3 S8 Standard -1.18 0.633 S9 Standard 2.60 1.136 1.44 95.1 S10 Standard -1.78 0.600 1.98 1 5.9 S11 Standard -3.25 1.302 S12 Standard Infinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 1.52 64.2 IMAGE Standard Infinity /

[0209] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 2b.

[0210] Table 2b

[0211]

[0212] The concave-convex condition of the object side surface or image side surface of each lens in the optical lens of this embodiment at the optical axis is shown in Table 2c.

[0213] Table 2c

[0214]

[0215] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 2d.

[0216] Table 2d

[0217] parameter L / F L / BFL T Numerical 7.00 3.62 1.627 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.28 -15.40 0.54 -79.20

[0218] Combine Figure 7 The structural diagram of the optical lens in the second embodiment shown in FIG. 2 and the main parameters of the optical lens in the second embodiment given in Tables 2a to 2c satisfy the relationship in Table 2d, obtained by simulation Figures 8 to 11 The simulation diagram shown. Figures 8 to 11 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 2.

[0219] from Figure 8 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0220] from Figure 9 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.05mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0221] from Figure 10 It can be seen that the astigmatism value of the optical lens is controlled between 0 and 0.06. 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.

[0222] from Figure 11 As can be seen from the figure, as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within the range of 80%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0223] In summary, the image height of the optical lens shown in Example 1 is 1.22 mm, indicating that the resolution of the optical lens is relatively high; the field of view is 160°, which can be applied to colonoscopy; and Figures 8-11 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0224] Figure 12 The structure of the optical lens of Example 3 is shown. The main differences between the structure of the optical lens of Example 3 and the optical lens of Example 1 are the parameters of each lens, the relationship they satisfy, the optical power, and the concave-convex condition at the optical axis.

[0225] As an optional embodiment of the present application, based on the third embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 3a to Table 3d.

[0226] Table 3a

[0227] Surface number Surface type R-value Thickness (mm) Refractive index Abbe number OBJ Stardard Infrinity 15 S1 Standard Infrinity 0.600 1.83 50.0 S2 Standard 0.90 0.349 S3 Standard -10.31 0.513 1.81 40.9 S4 Standard 1.70 0.818 2.00 28.3 S5 Standard -8.38 0.347 STO Standard Infinity 0.015 S7 Standard Infrinity 0.892 1.47 80.0 SS Standard -1.15 0.900 S9 Standard 3.40 1.134 1.57 75.3 S10 Standard -1.47 0.500 1.73 28.3 S11 Standard -5.50 1.213 S12 Standard Infinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 <![CDATA[ 15 2]]> 64.2 IMAGE Standard Infinity /

[0228] In the embodiment of the present application, the total optical length L of the optical lens is 8.28 mm; the focal length F is 1.23 mm; the image height is 1.26 mm; and the field of view angle is 135°.

[0229] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 3b.

[0230] Table 3b

[0231]

[0232] The concave-convex condition of the object side or image side of each lens in the optical lens of this embodiment at the optical axis is shown in Table 3. c shown.

[0233] Table 3c

[0234]

[0235] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 3d.

[0236] Table 3d

[0237] parameter L / F L / BFL T Numerical 6.73 3.90 1.556 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.19 12.60 0.16 -47

[0238] Combine Figure 12 The structural diagram of the optical lens in the third embodiment shown in FIG. 3 and the main parameters of the optical lens in the third embodiment given in Tables 3a to 3c satisfy the relationship in Table 3d, obtained by simulation Figures 13 to 16 The simulation diagram shown. Figures 13 to 16 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 3.

[0239] from Figure 13 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0240] from Figure 14 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.08mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0241] from Figure 15 It can be seen that the astigmatism value of the optical lens is controlled between 0.01 and 0.08. 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.

[0242] from Figure 16 As can be seen from the figure, as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within the range of 70%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0243] In summary, the image height of the optical lens shown in Example 1 is 1.26 mm, indicating that the resolution of the optical lens is relatively high; the field of view angle is 135°, which can be applied to gastroscopy; and Figure 13-16 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0244] Figure 17 The structure of the optical lens of Example 4 is shown. The main differences between the structure of the optical lens of Example 4 and the optical lens of Example 1 are the parameters of each lens, the relationship they satisfy, the optical power, and the concave-convex condition at the optical axis.

[0245] As an optional embodiment of the present application, based on the fourth embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 4a to Table 4d.

[0246] Table 4a

[0247] Surface number Surface type R-value Thickness (mm) Refractive index Abbe number OBJ Standard Infinity 10 S1 Standard Infinity 0.500 1.90 45.0 S2 Standard 0.90 0.422 S3 Standard -2.60 0.500 1.61 55.1 S4 Standard 2.11 0.800 2.00 28.3 S5 Standard -8.00 0.438 STO Standard Infinity 0.201 S7 Standard Infinity 0.810 1.52 80.0 S8 Standard -1.08 0.283 S9 Standard 2.67 0.940 1.60 60.3 S10 Standard -1.30 0.700 1.73 28.3 S11 Standard -7.35 0.599 S12 Standard Infinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 1.52 64.2 IMAGE Standard Infinity /

[0248] In the embodiment of the present application, the total optical length L of the optical lens is 7.19 mm; the focal length F is 0.74 mm; the image height is 0.74 mm; and the field of view angle is 135°.

[0249] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 4b.

[0250] Table 4b

[0251]

[0252] Table 4c shows the concave-convex condition of the object side surface or image side surface of each lens in the optical lens of this embodiment at the optical axis.

[0253] Table 4c

[0254]

[0255] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 4d.

[0256] Table 4d

[0257] parameter L / F L / BFL T Numerical 9.72 4.50 0.924 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.39 26.80 0.13 -32

[0258] Combine Figure 17 The structural diagram of the optical lens in the fourth embodiment shown in FIG. 4 and the main parameters of the optical lens in the fourth embodiment given in Tables 4a to 4c satisfy the relationship in Table 4d are obtained through simulation. Figures 18 to 21 The simulation diagram shown. Figures 18 to 21 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 4.

[0259] from Figure 18 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0260] from Figure 19 It can be seen that the axial value range of different wavelengths is controlled within the range of ±0.05mm, and the chromatic aberration is good in the entire entrance pupil range. Therefore, the axial point chromatic aberration of this optical lens is good.

[0261] from Figure 20 It can be seen that the astigmatism value of the optical lens is controlled between 0.01 and 0.04. 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 ±0.04mm, and the image quality of the optical lens is good.

[0262] from Figure 21 As can be seen from the figure, as the field of view angle 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.

[0263] In summary, the image height of the optical lens shown in Example 1 is 0.74 mm, indicating that the resolution of the optical lens is relatively high; the field of view angle is 135°, which can be applied to gastroscopy; and Figures 18-21 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0264] Figure 22 The structure of the optical lens of Example 5 is shown. The main differences between the structure of the optical lens of Example 5 and the optical lens of Example 1 are the parameters of each lens, the relationship they satisfy, the optical power, and the concave-convex condition at the optical axis.

[0265] As an optional embodiment of the present application, based on the fifth embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 5a to Table 5d.

[0266] In the embodiment of the present application, the total optical length L of the optical lens is 7.16 mm; the focal length F is 0.83 mm; the image height is 0.86 mm; and the field of view angle is 160°.

[0267] Table 5a

[0268] Surface number Surface type R-value Thickness (mm) Refractive index Abbe number OBJ Standard Infinity 8 S1 Standard Infinity 0.500 1.85 43.0 S2 Standard 0.78 0.437 S3 Standard -2.73 0.500 1.48 92.3 S4 Standard 4.35 0.802 2.00 28.3 S5 Standard -4.50 0.568 STO Standard Infinity 0.220 S7 Standard Infinity 0.751 1.46 90.3 S8 Standard -1.20 0.100 S9 Standard 1.52 0.935 1.44 95.1 S10 Standard -1.10 0.600 1.78 25.7 S11 Standard -3.85 0.753 S12 Standard Infinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 1.52 64.2 IMAGE Standard Infinity /

[0269] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 5b.

[0270] Table 5b

[0271]

[0272] The concave-convex condition of the object side or image side of each lens in the optical lens of this embodiment at the optical axis is shown in Table 5. c shown.

[0273] Table 5c

[0274]

[0275] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 5d.

[0276] Table 5d

[0277] parameter L / F L / BFL T Numerical 8.63 4.08 1.078 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.52 64.00 0.34 -69.400

[0278] Combine Figure 22 The structural diagram of the optical lens in the fifth embodiment shown in FIG. 5 and the main parameters of the optical lens in the fifth embodiment given in Tables 5a to 5c satisfy the relationship in Table 5d are obtained through simulation. Figures 23 to 26 The simulation diagram shown. Figures 23 to 26 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 5.

[0279] from Figure 23 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0280] from Figure 24 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.

[0281] from Figure 25 It can be seen that the astigmatism value of the optical lens is controlled between -0.01 and 0.03. 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 ±0.03mm, and the image quality of the optical lens is good.

[0282] from Figure 26 As can be seen from the figure, as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within the range of 80%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0283] In summary, the image height of the optical lens shown in Example 1 is 0.86 mm, indicating that the resolution of the optical lens is relatively high; the field of view is 160°, which can be applied to colonoscopy; and Figure 23-26 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0284] Figure 27 The structure of the optical lens of Example 6 is shown. The main differences between the structure of the optical lens of Example 6 and the optical lens of Example 1 are the parameters of each lens, the relationship they satisfy, the optical power, and the concave-convex condition at the optical axis.

[0285] As an optional embodiment of the present application, based on the sixth embodiment of the present application, the parameter values ​​of each lens of the optical lens can refer to Table 6a to Table 6d.

[0286] Table 6a

[0287] Surface number Surface type R-value Thickness (mn) Refractive index Abbe number OBJ Standard Infrinity 10 S1 Standard Infinity 0.500 1.S8 40.8 S2 Standard 0.80 0.433 S3 Standard -2.89 0.600 1.81 33.3 S4 Standard 1.30 0.822 2.00 28.3 S5 Standard -3.67 0.754 STO Standard Infinity 0.324 S7 Stardard Infinity 0.750 146 90.3 S8 Staindard -2.00 0.099 S9 Standard 1.82 0.450 1.78 25.7 S10 Standard 1.00 1.067 1.59 71.3 S11 Standard -4.52 1.081 S12 Standard Infiinity 0.650 1.52 64.2 S13 Standard Infinity 0.350 1.52 64.2 IMAGE Standard Infinity /

[0288] In the embodiment of the present application, the total optical length L of the optical lens is 7.87 mm; the focal length F is 0.76 mm; the image height is 0.81 mm; and the field of view angle is 160°.

[0289] The positive and negative conditions of the optical power of each lens in the optical lens of this embodiment are shown in Table 6b.

[0290] Table 6b

[0291]

[0292] The concave-convex condition of the object side or image side of each lens in the optical lens of this embodiment at the optical axis is shown in Table 6. c shown.

[0293] Table 6c

[0294]

[0295] The parameters of the optical lens in this embodiment satisfy the relationship shown in Table 6d.

[0296] Table 6d

[0297] parameter L / F L / BFL T Numerical 10.35 3.78 1.405 parameter Ndx-Ndy Vdx-Vdy Ndm-Ndn Vdm-Vdn Numerical -0.19 5.00 0.19 -45.60

[0298] Combine Figure 27 The structural diagram of the optical lens in Example 6 shown in FIG. 1 and the main parameters of the optical lens in Example 6 given in Tables 6a to 6c satisfy the relationship in Table 6d. The simulation results show that Figures 28 to 31 The simulation diagram shown. Figures 28 to 31 Shown are diagrams of magnification chromatic aberration, spherical aberration, astigmatism, and distortion of the optical lens in Example 6.

[0299] from Figure 28 It can be seen that as the field of view angle increases, the vertical chromatic aberration of the optical lens gradually increases, but the vertical axis chromatic aberration can be controlled within the offset allowed by the diffraction limit, making the chromatic aberration smaller and improving the imaging quality.

[0300] from Figure 29 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.

[0301] from Figure 30 It can be seen that the astigmatism value of the optical lens is controlled between -0.04 and 0.03. 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 ±0.04mm, and the image quality of the optical lens is good.

[0302] from Figure 31 As can be seen from the figure, as the field of view increases, the distortion of the optical lens gradually increases, but the distortion value can be controlled within the range of 80%, reducing the impact of image distortion on image quality. This shows that the imaging quality of the optical lens is good.

[0303] In summary, the image height of the optical lens shown in Example 1 is 0.81 mm, indicating that the resolution of the optical lens is relatively high; the field of view is 160°, which can be applied to colonoscopy; and Figures 28-31 It can be seen that the optical lens can achieve the goals of high resolution, wide field of view and high image quality.

[0304] The present application also provides an endoscope comprising the camera module of any of the above embodiments. The beneficial effects achieved by the endoscope are the same as those of the camera module of the above embodiments, which will not be described in detail here.

[0305] The present application also provides an endoscope system including a display, a light source host, an image processing device, and an endoscope. The beneficial effects achieved by the endoscope system are the same as those of the endoscope in the above embodiment, and will not be repeated here.

[0306] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An optical lens, characterized in that: comprising a plurality of lenses and apertures, wherein the number of the lenses is at least 6; The optical lens comprises a first glued lens G1 and a second glued lens G2, wherein the first glued lens G1 is formed by gluing two or three lenses, and the second glued lens G2 is formed by gluing two or three lenses, and the aperture is located between the first glued lens G1 and the second glued lens G2; The total optical length L of the optical lens and the focal length F of the optical lens satisfy the relationship: 6.50 <L / F<11.00。 2. The optical lens according to claim 1, characterized in that: Among the plurality of lenses, the number of the lenses having negative optical power is at least 2, and the number of the lenses having positive optical power is at least 2, wherein the lenses having negative optical power are negative lenses, and the lenses having positive optical power are positive lenses; The first cemented lens G1 is composed of one negative lens and one positive lens, so that the first cemented lens G1 has positive power; The second cemented lens G2 is composed of one negative lens and one positive lens, so that the second cemented lens G2 has positive refractive power.

3. The optical lens according to claim 2, characterized in that: In the first cemented lens G1, the refractive index Ndx of the negative lens and the refractive index Ndy of the positive lens satisfy the relationship: -0.60 <Ndx-Ndy<-0.15; The Abbe number Vdx of the negative lens and the Abbe number Vdy of the positive lens satisfy the relationship: <Vdx-Vdy<65。 4. The optical lens according to claim 2, characterized in that: In the second cemented lens G2, the refractive index Ndm of the negative lens and the refractive index Ndn of the positive lens satisfy the relationship: -0.60 <Ndm-Ndn<-0.15; The Abbe number Vdm of the negative lens and the Abbe number Vdn of the positive lens satisfy the relationship: <Vdm-Vdn<65。 5. The optical lens according to any one of claims 2 to 4, characterized in that: The number of the lenses is 6, and the aperture is located between the third lens and the fifth lens arranged from the object side to the image side.

6. The optical lens according to claim 5, characterized in that: The aperture stop is located between the third lens and the fourth lens arranged from the object side to the image side.

7. The optical lens according to claim 5, characterized in that: The second lens and the third lens arranged from the object side to the image side form the first cemented lens G1. The fifth lens and the sixth lens arranged from the object side to the image side form the second cemented lens G2.

8. The optical lens according to claim 7, characterized in that: The first lens arranged from the object side to the image side is the negative lens, and the fourth lens arranged from the object side to the image side is the positive lens.

9. A camera module, characterized in that: include: The optical lens according to any one of claims 1 to 8, The photosensitive element is arranged on the image side of the optical lens.

10. The camera module according to claim 9, characterized in that: A filter is also provided between the photosensitive element and the optical lens.

11. An endoscope, characterized in that: include: A camera module as described in any one of claims 9-10.

12. An endoscope system, characterized in that: include: A display, a light source host, an image processing device, and an endoscope as claimed in claim 11.

Images