Large target surface industrial high magnification lens and camera module

Abstract

The embodiment of the application relates to the technical field of optical imaging, and provides a large-target industrial high-magnification lens and a camera module, the large-target industrial high-magnification lens comprising a zoom lens group and a fixed-focus lens group arranged from an object side to an image side; the zoom lens group comprising a first lens group, a second lens group, a diaphragm, a third lens group and a fourth lens group arranged in sequence from the object side to the image side, the first lens group, the second lens group and the fourth lens group all having positive refractive powers, and the third lens group having a negative refractive power; wherein the first lens group and the fourth lens group are fixed relative to the fixed-focus lens group, the second lens group and the third lens group can move relative to the fixed-focus lens group along the optical axis of the large-target industrial high-magnification lens to zoom, the diaphragm is relatively fixed with one of the second lens group and the third lens group, the moving directions of the second lens group and the third lens group are opposite, and the beam angle of light rays between the zoom lens group and the fixed-focus lens group is less than 1°.

Description

Technical Field

[0001] This application relates to the field of large-area industrial high-magnification lens technology, and in particular to a large-area industrial high-magnification lens and camera module. Background Technology

[0002] With the rapid development of China's economy in recent years, the demand for industrial product testing has become increasingly stringent, which has also driven the progress of the optical industry. As testing equipment is constantly updated, the demand and requirements for industrial lenses used in testing are also increasing.

[0003] Currently available industrial lenses can be matched with large image sensors, providing a wide field of view. However, their magnification is fixed and limited, failing to meet the needs of various scenarios. While some industrial lenses can be adapted to different objects by adjusting the magnification, the magnification of industrial lenses in related technologies is relatively low, resulting in lower detection accuracy. Summary of the Invention

[0004] The embodiments of this application provide a large-area industrial high-magnification lens and camera module that can well balance large target area, high magnification and high imaging quality.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: In a first aspect, embodiments of this application provide a large-aperture industrial high-magnification lens, comprising a zoom lens group and a fixed-focus lens group arranged from the object side to the image side; the zoom lens group includes a first lens group, a second lens group, an aperture stop, a third lens group, and a fourth lens group arranged sequentially from the object side to the image side, wherein the first lens group, the second lens group, and the fourth lens group all have positive optical power, and the third lens group has negative optical power; wherein the first lens group and the fourth lens group are fixed relative to the fixed-focus lens group, the second lens group and the third lens group are both movable relative to the fixed-focus lens group along the optical axis of the large-aperture industrial high-magnification lens, the aperture stop is fixed relative to one of the second lens group and the third lens group, and the second lens group and the third lens group move in opposite directions, so that the large-aperture industrial high-magnification lens can zoom between the wide-angle end and the telephoto end; the beam angle between the zoom lens group and the fixed-focus lens group is less than 1°.

[0006] In some feasible implementations, the second lens group is a compensation group, the third lens group is a focusing group, and the aperture stop is fixed relative to the second lens group.

[0007] In some feasible embodiments, the second lens group and the third lens group can be linked along the optical axis.

[0008] In some feasible implementations, the zoom ratio of the large-aperture industrial high-magnification lens is 2; wherein the zoom ratio is the ratio of the focal length of the zoom lens group at the telephoto end to the focal length of the zoom lens group at the wide-angle end.

[0009] In some feasible ways, during the zooming process of the large-area industrial high-magnification lens, the angle between the image-side principal rays is less than or equal to 1°.

[0010] In some feasible implementations, the large-area industrial high-magnification lens comprises multiple lenses; the refractive indices of the positive lenses in the first lens group and the second lens group satisfy the following relationship: , where nd Lx The refractive index of the Xth lens arranged from the object side to the image side in the large-area industrial high-magnification lens; and / or; the Abbe number of the positive lenses in the first lens group and the second lens group satisfies the following relationship: , among which, vd Lx The Abbe number is the Xth lens arranged from the object side to the image side in the large-area industrial high-magnification lens; wherein the positive lens is the lens with positive optical power.

[0011] In some feasible embodiments, the large-area industrial high-magnification lens comprises multiple lenses, the second lens group comprising a cemented lens and a positive lens; the third lens group comprising a cemented lens and a negative lens; the cemented lens comprising two or three of the lenses, the positive lens being the lens having positive optical power, and the negative lens being the lens having negative optical power.

[0012] In some possible implementations, the cemented lens in the second lens group is located on the side away from the aperture stop, and the cemented lens in the third lens group is located on the side closer to the aperture stop.

[0013] In some feasible implementations, the positive lens in the second lens group is a biconvex lens.

[0014] The beneficial effects of the large-format industrial high-magnification lens provided in this application are as follows: By moving the second and third lens groups in the zoom lens group, the large-format industrial high-magnification lens can zoom between the wide-angle and telephoto ends. Simultaneously, the second and third lens groups move in opposite directions, which not only facilitates achieving high magnification but also effectively corrects aberrations during zooming, improving image quality. Furthermore, by rationally allocating the optical power of each lens group in the zoom lens group, aberrations are further corrected, thereby improving image quality. Based on this, by rationally arranging the number of lenses in each lens group of the large-format industrial high-magnification lens, it is beneficial to achieve a balance between high magnification and a large surface area. In addition, by adjusting the position of the aperture stop and optimizing the beam angle between the focal lens group and the fixed-focus lens group in the large-format industrial high-magnification lens, the object-side telecentricity during zooming can be effectively guaranteed, thereby improving detection accuracy. Thus, the large-format industrial high-magnification lens achieves the goal of balancing a large surface area, high magnification, high image quality, and detection accuracy.

[0015] Secondly, embodiments of this application provide a camera module, including the large-area industrial high-magnification lens and photosensitive element described in the first aspect, wherein the photosensitive element is disposed on the image side of the large-area industrial high-magnification lens.

[0016] The camera module in this embodiment has the same structure and technical effect as the medium-long telephoto zoom lens in the first aspect, and will not be described again here. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a large-area industrial high-magnification lens provided in an embodiment of this application at 5X magnification; Figure 2 A schematic diagram of the structure of a large-area industrial high-magnification lens provided in an embodiment of this application at 7X magnification; Figure 3 A schematic diagram of the structure of the large-area industrial high-magnification lens provided in the embodiments of this application at 10X magnification; Figure 4 The energy transfer function (MTF) graph of the large-area industrial high-magnification lens provided in the embodiments of this application at 5X magnification; Figure 5 The energy transfer function (MTF) diagram of the large-area industrial high-magnification lens provided in the embodiments of this application at 7X magnification; Figure 6 The energy transfer function (MTF) graph of the large-area industrial high-magnification lens provided in the embodiments of this application at 10X magnification; Figure 7 A focal shift diagram of a large-area industrial high-magnification lens provided in this application embodiment at 5X magnification; Figure 8 A focal shift diagram of a large-area industrial high-magnification lens provided in this application embodiment at 7X magnification; Figure 9 A focal shift diagram of a large-area industrial high-magnification lens provided in this application embodiment at 10X magnification; Figure 10 Field curvature diagram of a large-area industrial high-magnification lens provided in this application embodiment at 5X magnification; Figure 11 Field curvature diagram of a large-area industrial high-magnification lens provided in this application embodiment at 7X magnification; Figure 12 The field curvature diagram of the large-area industrial high-magnification lens provided in the embodiments of this application at 10X magnification.

[0018] Figure 13 The distortion diagram of the large-area industrial high-magnification lens provided in the embodiments of this application at 5X magnification; Figure 14 The distortion diagram of the large-area industrial high-magnification lens provided in the embodiments of this application at 7X magnification; Figure 15 The distortion diagram of a large-area industrial high-magnification lens at 10X provided for embodiments of this application; The following are the labeling elements in the figure: Zoom lens group J01; Fixed lens group J02; First lens group G01; Second lens group G02; Third lens group G03; Fourth lens group G04; 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; Eleventh lens L11; Twelfth lens L12; Thirteenth lens L13; Fourteenth lens L14; Fifteenth lens L15; Sixteenth lens L16; Seventeenth lens L17; Eighteenth lens L18; Eleventh lens L19; Twentieth lens L20; Twenty-first lens L21; Twenty-second lens L22; Aperture stop STO; Image plane IMAGE. Detailed Implementation

[0019] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0020] 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 a large-format industrial high-magnification lens to deflect light.

[0021] A lens or lens group with positive optical power, having a positive focal length, and having the effect of converging light.

[0022] A lens or lens group with negative optical power has a negative focal length and has the effect of diverging light.

[0023] Focal length, also known as focal length, is a measure of light convergence or divergence in large-format, high-magnification industrial lenses. It refers to the perpendicular distance from the optical center of a lens or lens group to the focal plane when a distant object is projected into a sharp image. For prime lenses, the position of their optical center remains constant; for telephoto lenses, changes in the optical center result in changes in the focal length.

[0024] The effective focal length (EFL) of a lens refers to the distance from the center of the lens to the focal point.

[0025] The composite focal length is the combination of the focal lengths of the individual lenses in the lens group.

[0026] The object side is defined by the lens; the side where the object is located is called the object side, and the surface of the lens closest to the object side is called the object side surface.

[0027] The image side is the side on which the image of the object is located, with the lens as the boundary. The surface of the lens closest to the image side is called the image side surface.

[0028] An aperture diaphragm is a device used to control the amount of light passing through the lens and entering the sensor inside the camera body; it is usually located inside the lens.

[0029] The imaging plane is located on the image side of all lenses in a large-format industrial high-magnification lens, and is the surface on which the image is formed after light passes through each lens in the large-format industrial high-magnification lens in sequence.

[0030] The optical axis is a vertical axis that passes through the center of a lens. In large-format industrial high-magnification lenses, the optical axis is the axis passing through the centers of each lens element.

[0031] The focal point is the point where parallel light rays converge after being refracted by a lens or lens group.

[0032] The Abbe number, also known as the dispersion coefficient, is the ratio of the difference in refractive index of an optical material at different wavelengths, representing the degree of dispersion of the material.

[0033] Aberrations: Large-aperture industrial high-magnification lenses have the properties of an ideal optical system at the optical axis. Near-axis rays emitted from a point on the object intersect the image plane at a point (i.e., the optical axis image point). However, in reality, rays passing through different apertures of the lens rarely intersect perfectly at a single point. Instead, they deviate from the position of the paraxial image point. These differences are collectively referred to as aberrations.

[0034] Distortion, also known as image distortion, refers to the degree of distortion of the image formed by a large-format, high-magnification industrial lens relative to the object itself. Distortion is caused by the spherical aberration of the aperture; the height of the intersection point between the principal ray from different fields of view and the Gaussian image plane after passing through the lens is not equal to the ideal image height. The difference between the two is the distortion.

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] In the embodiments of this application, 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 indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0037] like Figure 1 As shown, in some embodiments, the camera module includes a large-area industrial high-magnification lens and a photosensitive element (not shown in the figure), with the photosensitive element located on the image side of the large-area industrial high-magnification lens.

[0038] The working principle of the camera module is as follows: the light reflected from the subject passes through a large-area industrial high-magnification lens to generate an optical image, which is then projected onto the photosensitive surface of the photosensitive element. The photosensitive element converts the optical image into an electrical signal, i.e., an analog image signal, and transmits it to the processor.

[0039] Among them, the photosensitive element (also known as the image sensor) is located in Figure 1The image sensor on the far right (IMAGE) is a semiconductor chip containing hundreds of thousands to millions of photodiodes that generate electrical charges when illuminated. The photosensitive element can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. A CCD is made of a highly sensitive semiconductor material that converts light into electrical charges. A CCD consists of many photosensitive units, typically measured in megapixels. When light illuminates the surface of the photosensitive element, each photosensitive unit reflects a charge onto the component. The signals generated by all the photosensitive units are added together to form a complete image.

[0040] Among them, the large-format industrial high-magnification lens mainly uses the refraction principle of the lens to form an image. That is, the light from the scene passes through the large-format industrial high-magnification lens and forms a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element located on the focal plane.

[0041] The aforementioned large-scale industrial high-magnification lenses refer to zoom lenses with a target area greater than or equal to 67mm, used for industrial inspection.

[0042] like Figure 1 As shown in the illustration, this application provides a large-aperture industrial high-magnification lens, including a zoom lens group J01 and a fixed-focus lens group J02 arranged from the object side to the image side. The zoom lens group J01 includes a first lens group G01, a second lens group G02, an aperture stop STO, a third lens group G03, and a fourth lens group G04 arranged sequentially from the object side to the image side. The first lens group G01, the second lens group G02, and the fourth lens group G04 all have positive optical power; the third lens group G03 has negative optical power. By rationally allocating the optical power of each lens group in the large-aperture industrial high-magnification lens, aberrations can be effectively corrected, thereby improving image quality.

[0043] In some feasible implementations, the second lens group G02 is a compensation group, the third lens group G03 is a zoom group, the aperture stop STO is fixed relative to the second lens group G02, and the second lens group G02 and the third lens group G03 move in opposite directions.

[0044] The aforementioned zoom module is responsible for changing the focal length of large-aperture industrial high-magnification lenses. When it moves, the image plane position shifts drastically.

[0045] The aforementioned compensation group is responsible for compensating for image plane displacement caused by the movement of the zoom group, ensuring that the image plane remains stable on the imaging plane.

[0046] By moving the second lens group G02 and the third lens group G03 in opposite directions, the distances between the various lens groups in the zoom lens group J01, especially the distance between the second lens group G02 and the third lens group G03, change rapidly. This not only facilitates high magnification but also effectively corrects aberrations during zooming, improving image quality. Furthermore, by rationally allocating the optical power of each lens group in the zoom lens group, aberrations are further corrected, thus improving image quality. Based on this, by rationally arranging the number of lenses in each lens group of a large-aperture industrial high-magnification lens, it is beneficial to achieve a balance between high magnification and a large aperture.

[0047] Based on this, the aforementioned second lens group G02 and third lens group G03 can, but are not limited to, move in tandem to achieve zoom. Compared to the individual movement of the second lens group G02 and the third lens group G03, the linkage not only improves the zoom speed but also enables image plane compensation during zooming, resulting in clear imaging. The large-area industrial high-magnification lens of this application, through the reverse linkage of the second lens group G02 and the third lens group G03, can achieve clear imaging within the 5X-10X magnification range.

[0048] The linkage between the focusing group and the compensation group mentioned above refers to the fact that, in order to maintain focus during zooming, the two lens groups must move according to a specific non-linear relationship. This linkage can be achieved through a precision mechanical cam. The curve of this cam determines the movement trajectory of the compensation group.

[0049] In addition, during the movement of the second lens group G02 and the third lens group G03, the first lens group G01, the fourth lens group G04 in the zoom lens group J01, and the fixed lens group J02 are relatively fixed. In this way, the large-format industrial high-magnification lens can effectively control the total optical length of the large-format industrial high-magnification lens while achieving high magnification, thereby achieving the goal of balancing high magnification, large surface area, and small size.

[0050] It should be noted that the second lens group G02 and the third lens group G03 mentioned above can, but are not limited to, be linked. This helps to improve zoom efficiency and facilitate user operation while achieving a wide zoom range.

[0051] Of course, the second lens group G02 and the third lens group G03 can also achieve zoom by moving themselves, which is not specifically limited here.

[0052] The aforementioned aperture stop STO is relatively fixed to one of the second lens group G02 and the third lens group G03. That is, while the second lens group G02 and the third lens group G03 move to achieve focusing, the aperture stop STO can move with either the second lens group G02 or the third lens group G03. By adjusting the actual position of the aperture stop STO, the beam angle of light between the focal lens group J01 and the fixed lens group J02 in the large-scale industrial high-magnification lens is optimized. Through multiple experiments, the beam angle of light between the zoom lens group J01 and the fixed lens group G02 is made less than 1°. In this way, the object-side telecentricity can be effectively guaranteed during the zoom process, thereby improving the detection accuracy.

[0053] In summary, this enables the large-area industrial high-magnification lens to achieve the goals of large target area, high magnification, high imaging quality, and detection accuracy.

[0054] It should be noted that the aforementioned aperture STO can move with the second lens group G02, and the aforementioned aperture STO can also move with the third lens group G03, without any specific limitation here.

[0055] refer to Figure 1 In this embodiment, the first lens group G01 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 arranged sequentially from the object side to the image side; the second lens group G02 includes a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially from the object side to the image side; the third lens group G03 includes a tenth lens L10, an eleventh lens L11, and a twelfth lens L12 arranged sequentially from the object side to the image side; the fourth lens group G04 includes a thirteenth lens L13, a fourteenth lens L14, a fifteenth lens L15, a sixteenth lens L16, a seventeenth lens L17, an eighteenth lens L18, and a nineteenth lens L19 arranged sequentially from the object side to the image side; and the fixed-focus group J02 includes a twentieth lens L20, a twenty-first lens L21, and a twenty-second lens L22 arranged sequentially from the object side to the image side. In other words, the large-aperture industrial high-magnification lens comprises a total of 22 lenses.

[0056] In some feasible implementations, within the 22 lenses of a large-aperture industrial high-magnification lens, each lens group includes cemented lenses, with each cemented lens comprising two or three lenses bonded together. This not only effectively eliminates chromatic aberration and improves tolerance sensitivity but also simplifies the structure, reduces assembly difficulty, and facilitates the assembly of large-aperture industrial high-magnification lenses. In particular, the second lens group G02 and the third lens group G03 both include cemented lenses. This not only dynamically eliminates chromatic aberration but also reduces the number of individual lenses in moving parts, enabling lightweight design and faster movement, thereby improving zoom efficiency.

[0057] In some feasible implementations, the second lens group G02 includes a cemented lens and a positive lens, and the third lens group G03 includes a cemented lens and a negative lens. The positive lens is a lens with positive optical power, and the negative lens is a lens with negative optical power. This arrangement not only effectively reduces aberrations by appropriately matching the optical powers of the second lens group G02 and the third lens group G03, but also corrects chromatic aberration by using a cemented lens. Furthermore, it reduces the angle of incidence of light, thereby lowering the tolerance sensitivity of large-aperture industrial high-magnification lenses and achieving higher image resolution.

[0058] refer to Figure 1 The second lens group G02 includes a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged from the object side to the image side. The third lens group G03 includes a tenth lens L10, an eleventh lens L11, and a twelfth lens L12 arranged from the object side to the image side. The seventh lens L7 and the eighth lens L8 are cemented together to form a cemented lens; the tenth lens L10 and the eleventh lens L11 are also cemented together to form a cemented lens. This makes the structures of the second lens group G02 and the third lens group G03, located on either side of the aperture stop STO, approximately symmetrical. In some feasible implementations, the lens closest to the aperture stop STO in the second lens group G02, i.e., the ninth lens L9, is a biconvex lens. This arrangement effectively reduces the principal ray angle of the system, achieving image-side telecenty.

[0059] It should be noted that the large-area industrial high-magnification lens of this application may include not only 22 lenses, but also 10, 11, 12, ..., 20, 21, 23, 24, 25, ... and other numbers of lenses, without specific limitation here.

[0060] In some feasible implementations, the refractive indices of the positive lenses in the first lens group G01 and the second lens group G02 satisfy the following relationship: , where nd Lx The Xth lens L in a large-area industrial high-magnification lens is arranged from the object side to the image side. X The refractive index of the lens; the Abbe number of the positive lenses in the first lens group G01 and the second lens group G02 satisfies the following relationship: , among which, vd Lx The Xth lens L in a large-area industrial high-magnification lens is arranged from the object side to the image side. X The Abbe number; where the positive lens is a lens with positive optical power. By reasonably selecting the material of the positive lens in the first lens group G01 and the second lens group G02, when the material of the positive lens is an aberrant dispersion material, this setting can effectively eliminate chromatic aberration, thereby improving image quality.

[0061] Figures 1 to 3 The diagram illustrates the structure of the large-aperture industrial high-magnification lens of this application at different magnifications. The large-aperture industrial high-magnification lens includes a zoom lens group J01 and a fixed-focus lens group J02 arranged from the object side to the image side. The zoom lens group J01 includes a first lens group G01, a second lens group G02, an aperture stop STO, a third lens group G03, and a fourth lens group G04 arranged from the object side to the image side. The first lens group G1, the second lens group G2, and the fourth lens group G4 all have positive optical power; the third lens group G3 has negative optical power.

[0062] Wherein: the first lens group G01 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6 arranged sequentially from the object side to the image side; the first lens L1 and the second lens L2 are cemented together to form a cemented lens; the fifth lens L5 and the sixth lens L6 are cemented together to form a cemented lens.

[0063] The second lens group G02 includes a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged sequentially from the object side to the image side. The seventh lens L7 and the eighth lens L8 are cemented together to form a cemented lens.

[0064] The third lens group G03 includes a tenth lens L10, an eleventh lens L11, and a twelfth lens L12 arranged sequentially from the object side to the image side; the tenth lens L10 and the eleventh lens L11 are cemented together to form a cemented lens.

[0065] The fourth lens group G04 includes the thirteenth lens L13, the fourteenth lens L14, the fifteenth lens L15, the sixteenth lens L16, the seventeenth lens L17, the eighteenth lens L18, and the nineteenth lens L19 arranged sequentially from the object side to the image side. The thirteenth lens L13 and the fourteenth lens L14 are cemented together to form a cemented lens, and the seventeenth lens L17 and the eighteenth lens L18 are cemented together to form a cemented lens.

[0066] In this embodiment, the second lens group G02 is a compensation group, the third lens group G03 is a zoom group, and the aperture stop STO is fixed relative to the second lens group G02. The second lens group G02 and the third lens group G03 can be, but are not limited to, linked together, and their movement directions are opposite. That is, the second lens group G02 and the third lens group G03 achieve zooming and image plane compensation simultaneously through reverse linkage, thereby achieving clear imaging between the wide-angle and telephoto ends.

[0067] Tables 1a to 1e provide the specific parameter values ​​for each lens of a large-area industrial high-magnification lens according to an optional embodiment of this application.

[0068] It should be noted that in Table 1a, "Surface Number" refers to the number of each surface arranged sequentially from the object side to the image side. The radius R value is the lens corresponding to the surface number, which is the radius of curvature of the object side or image side of the lens corresponding to each surface number on the optical axis. "Infinite" in the "Radius of Curvature" parameter series means that the object side or image side of the lens is a plane. The first value in the "Thickness" parameter series for each lens is the thickness of the lens on the optical axis, and the second value is the distance on the optical axis from the image side of the lens to the object side of the next lens.

[0069]

[0070] In this embodiment, the large-aperture industrial high-magnification lens achieves zoom by moving between the second lens group G02 and the third lens group G03 in reverse linkage, between the wide-angle end and the telephoto end, that is, between the maximum magnification of 10x (10X) and the minimum magnification of 5X. Therefore, when the large-aperture industrial high-magnification lens is at the three magnifications of 5X, 7X, and 10X, the distance between two adjacent lens groups in the zoom lens group is different. In this embodiment, the conjugate distance of the large-aperture industrial high-magnification lens is 550mm, where the conjugate distance refers to the distance between the object (image taken from the large-aperture industrial high-magnification lens) and the distance between the two lens groups. Figure 1 The object plane referred to by OBJ in the image plane is to its imaging plane. Figure 1 The total distance between (as indicated by IMAGE in the image). Magnification range is 5X-10X.

[0071] Table 1b below shows the large-area industrial high-magnification lenses shown in Table 1a at three magnifications: 5X, 7X, and 10X. Figure 1 The values ​​of the thickness between the three lens groups. Among them, d(12) represents the distance between the first lens group G01 and the second lens G02; d(23) represents the distance between the second lens group G02 and the third lens G03; d(23) represents the distance between the third lens group G03 and the fourth lens G04.

[0072]

[0073] The large-aperture industrial high-magnification lens of this application can achieve a maximum magnification of 10X and a minimum magnification of 5X. As shown in Table 1b above, at the telephoto end (5X magnification), the focal length of zoom lens group J01 is 27mm. At the wide-angle end (10X magnification), the focal length of zoom lens group J01 is 13.5mm, resulting in a zoom ratio of 2. This demonstrates that the large-aperture industrial high-magnification lens achieves both high magnification and a wide magnification range.

[0074] The positive and negative values ​​of the optical power of each lens in the large-area industrial high-magnification lens in the embodiment are shown in Table 1c.

[0075]

[0076] It should be noted that the "+" and "-" in Table 1c represent the positive and negative optical power of each lens in the large-area industrial high-magnification lens of Example 1. "+" indicates that the lens has positive optical power; "-" indicates that the lens has negative optical power.

[0077] The concavity or convexity of the object side or image side of each lens in the large-target industrial high-magnification lens of the embodiment at the optical axis is shown in Table 1d.

[0078]

[0079] It should be noted that in Table 1d, "+-", "-+", "--", "+∞", and "∞-" represent the concavity / convexity of the object-side or image-side of each lens along the optical axis. Specifically, "+-" indicates that both the object-side and image-side of the lens are convex towards the object along the optical axis, i.e., a biconvex structure; "-+" indicates that both the object-side and image-side of the lens are concave towards the object along the optical axis, i.e., a biconcave structure; "--" indicates that both the object-side and image-side of the lens are concave towards the object along the optical axis; "+∞" indicates that the object-side of the lens is convex towards the object along the optical axis, while the image-side is flat along the optical axis; and "∞-" indicates that the object-side of the lens is flat along the optical axis, while the image-side is concave towards the object along the optical axis. Of course, in addition to the above-mentioned concave and convex configurations, the lenses in large-area industrial high-magnification lenses can also include any one or more of "++", "∞+", and "-∞". Among them, "++" means that both the object-side and image-side surfaces of the lens are convex towards the object side at the optical axis; "∞+" means that the object-side surface of the lens is flat at the optical axis and the image-side surface is convex towards the object side at the optical axis; "-∞" means that the object-side surface of the lens is concave towards the object side at the optical axis and the image-side surface is flat at the optical axis. No specific limitation is made here.

[0080] In this embodiment, the lenses with positive optical power in the first lens group G01 and the second lens group G02, namely the positive lenses, are the first lens L1, the third lens L3, the fourth lens L4, the fifth lens L5, the eighth lens L8 and the ninth lens L9. The refractive index and Abbe number of the above positive lenses are shown in Table 1e.

[0081]

[0082] As can be seen from Table 1e, the refractive indices of the positive lenses in the first lens group G01 and the second lens group G02 satisfy the following relationship: 1.40 ≤ ndLx ≤1.60, where nd Lx The Xth lens L in a large-area industrial high-magnification lens is arranged from the object side to the image side. X The refractive index of the lens; the Abbe number of the positive lens satisfies the relationship: 65.0 ≤ vd Lx ≤95.5, where vd Lx The Xth lens L in a large-area industrial high-magnification lens is arranged from the object side to the image side. X The Abbe number; where the positive lens is a lens with positive optical power. By reasonably selecting the material of the positive lens in the first lens group G01 and the second lens group G02, when the material of the positive lens is an aberrant dispersion material, this setting can effectively eliminate chromatic aberration, thereby improving image quality.

[0083] The large-aperture industrial high-magnification lens of this application achieves a maximum magnification of 10X, a minimum magnification of 5X, and a zoom ratio of 2. This demonstrates that the large-aperture industrial high-magnification lens achieves both high magnification and a wide magnification range.

[0084] Combination Figures 1-3 A schematic diagram of the structure of a large-aperture industrial high-magnification lens is provided, along with Tables 1a to 1e, which list the main parameters of the lens and the concavity / convexity of each lens along the optical axis. Simulations were used to obtain the energy transfer function (MTF), focal shift, field curvature, and distortion diagrams of this large-aperture industrial high-magnification lens at three different magnifications between the telephoto and wide-angle ends. Figures 4-15 .

[0085] Among them, the Energy Transfer Function (MTF) graph, or MTF graph for short, is a modulation transfer function graph. The horizontal axis of the MTF graph is the distance from the center to the edge, and the vertical axis reflects the quality of contrast, or in other words, the quality of image reproduction. The MTF graph is a curve that reflects the contrast (image reproduction) of large-format industrial high-magnification lenses. The higher the value of the vertical axis of the MTF graph, the better the image reproduction and the higher the resolution of the large-format industrial high-magnification lens.

[0086] The field curvature diagram above shows the field curvature value of this large-area industrial high-magnification lens as the field of view changes. The horizontal axis represents the magnitude of the field curvature, the vertical axis represents the normalized field of view height, the solid line represents the meridional direction, and the dashed line represents the sagittal direction. In the field of optical imaging, the field curvature value within 0.8 of the field of view is typically used to determine the resolving power of an optical lens.

[0087] from Figures 10 to 12This indicates that the field curvature in both directions of the large-area industrial high-magnification lens has been well corrected, and the overall resolving power performance of the large-area industrial high-magnification lens is excellent.

[0088] The distortion graph above represents the percentage distortion of this large-area industrial high-magnification lens as the field of view changes, where the horizontal axis represents the percentage distortion and the vertical axis represents the normalized field of view height. From Figures 13 to 15 It can be seen that the maximum absolute value of this large-area industrial high-magnification lens is no higher than 0.1%, and the image is basically without distortion.

[0089] Combination Figures 4-15 It can be seen that the large-area industrial high-magnification lens in this embodiment meets the optical performance requirements in terms of fidelity, resolution, and distortion, indicating that the large-area industrial high-magnification lens has good optical performance.

[0090] In summary, the large-area industrial high-magnification lens in this embodiment achieves high magnification and an object-side resolution of up to 1µm, indicating high detection accuracy. While maintaining minimal distortion, its target area can reach 67mm. This achieves a balance between high magnification, a large target area, and high imaging quality, demonstrating that the large-area industrial high-magnification lens offers high detection accuracy when applied to industrial inspection.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A large-area industrial high-magnification lens, characterized in that, This includes zoom lens groups and fixed-focus lens groups arranged from the object side to the image side; The zoom lens group includes a first lens group, a second lens group, an aperture stop, a third lens group, and a fourth lens group arranged sequentially from the object side to the image side. The first lens group, the second lens group, and the fourth lens group all have positive optical power, and the third lens group has negative optical power. In this design, the first lens group and the fourth lens group are fixed relative to the fixed-focus lens group. The second lens group and the third lens group are both movable relative to the fixed-focus lens group along the optical axis of the large-aperture industrial high-magnification lens. The aperture stop is fixed relative to one of the second lens group and the third lens group. The second lens group and the third lens group move in opposite directions to enable the large-aperture industrial high-magnification lens to zoom between the wide-angle end and the telephoto end. The beam angle between the zoom lens group and the fixed-focus lens group is less than 1°.

2. The large-area industrial high-magnification lens according to claim 1, characterized in that, The second lens group is a compensation group, the third lens group is a focusing group, and the aperture stop is fixed relative to the second lens group.

3. The large-area industrial high-magnification lens according to claim 1, characterized in that, The second lens group and the third lens group can be linked along the optical axis.

4. The large-area industrial high-magnification lens according to claim 1, characterized in that, The zoom ratio of the large-aperture industrial high-magnification lens is 2; wherein, the zoom ratio is the ratio of the focal length of the zoom lens group at the telephoto end to the focal length of the zoom lens group at the wide-angle end.

5. The large-area industrial high-magnification lens according to claim 1, characterized in that, During the zooming process of the large-target industrial high-magnification lens, the angle between the principal rays on the image side is less than or equal to 1°.

6. The large-area industrial high-magnification lens according to any one of claims 1-5, characterized in that, The large-area industrial high-magnification lens includes multiple lenses; The refractive indices of the positive lenses in the first lens group and the second lens group satisfy the following relationship: , where nd Lx The refractive index of the Xth lens arranged from the object side to the image side in the large-area industrial high-magnification lens; and / or; The Abbe numbers of the positive lenses in the first lens group and the second lens group satisfy the following relationship: , among which, vd Lx The Abbe number of the Xth lens arranged from the object side to the image side in the large-area industrial high-magnification lens; The positive lens is a lens with positive optical power.

7. The large-area industrial high-magnification lens according to any one of claims 1-5, characterized in that, The large-area industrial high-magnification lens includes multiple lenses, the second lens group includes a cemented lens and a positive lens; the third lens group includes a cemented lens and a negative lens. The cemented lens comprises two or three lenses, wherein the positive lens is the lens with positive optical power and the negative lens is the lens with negative optical power.

8. The large-area industrial high-magnification lens according to claim 7, characterized in that, The cemented lens in the second lens group is located on the side away from the aperture stop, and the cemented lens in the third lens group is located on the side closer to the aperture stop.

9. The large-area industrial high-magnification lens according to claim 7, characterized in that, The positive lens in the second lens group is a biconvex lens.

10. A camera module, characterized in that, include: Large-area industrial high-magnification lens as described in any one of claims 1 to 9; A photosensitive element is disposed on the image side of the large-area industrial high-magnification lens.

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