Optical lens, camera module, and terminal

Abstract

The present application provides an optical lens, a camera module, and a terminal. By providing at least one non-rotationally symmetric lens in the lenses of the optical lens for imaging, the non-rotationally symmetric lens can adjust the symmetry relationship of the imaging area of the optical lens to two-axis symmetry, that is, there are two axes of symmetry for the imaging area, and the two axes of symmetry extend along the first direction and the second direction respectively. When the optical lens including the non-rotationally symmetric lens images a three-dimensional scene, it generates a contraction distortion along the first direction and / or a contraction distortion along the second direction, which can exactly correct the stretching deformation generated when the edge objects of the three-dimensional scene are imaged. At the same time, the deformations along these two directions can keep the straight lines in the image horizontal and vertical and still remain straight lines, so that the contraction distortion is not easily detected, thereby obtaining better imaging.

Description

[0001] This application is a divisional application. The application number of the original application is 201911403975.8, and the application date of the original application is December 28, 2019. The entire content of the original application is incorporated herein by reference. Technical Field

[0002] Embodiments of the present application relate to the field of lenses, and more particularly to an optical lens, a camera module, and a terminal. Background Art

[0003] When using a lens to obtain an image, the edge image often distorts. For example, in a group photo scenario, the edge figures often deform, looking fatter, stretched, etc. This phenomenon is more obvious during the process of shooting or video recording with a wide-angle lens with a large imaging field of view.

[0004] Please refer to Figure 1 , Figure 1 which shows a schematic diagram of the optical path principle when an optical lens captures an image of a three-dimensional scene. As can be seen from Figure 1 , the distortion of the edge of the image captured by the lens has nothing to do with imaging aberration. This distortion is caused by the objective projection relationship, resulting in the deformation of three-dimensional objects and poor image quality. Specifically, Figure 1 includes a lens 1, an object to be imaged A, an object to be imaged B, and an object to be imaged C on the object side of the lens 1, and an image A′, an image B′, and an image C′ on the object-image side of the lens 1. Among them, the objects to be imaged A, B, and C are spherical structures of the same size. The objects to be imaged B and C are respectively located on both sides of the object to be imaged A. The object to be imaged A faces the lens A directly, and the objects to be imaged B and C are both located at the edge of the imaging view angle of the lens 1. The image B′ formed by the object to be imaged B and the image C′ formed by the object to be imaged C are respectively located on both sides of the image A′ formed by the object to be imaged A. It can be seen from the figure that the sizes of the images formed by the objects to be imaged A, B, and C of the same size are different. The imaging of the objects to be imaged B and C closer to the edge of the imaging view angle is larger than that of the object to be imaged A facing the lens 1 directly, that is, the objects to be imaged located at the edge of the imaging view angle are stretched. Summary of the Invention

[0005] Embodiments of the present application provide an optical lens, a camera module including the optical lens, and a terminal including the camera module, aiming to avoid the edge of the image obtained by the optical lens from deforming and obtain a high-quality image.

[0006] In a first aspect, an optical lens is provided. The optical lens includes a plurality of lenses arranged from the object side to the image side, and at least one aspherical lens is included in the plurality of lenses. The aspherical lens is configured to adjust the symmetry characteristic of the imaging area of the optical lens to two-axis symmetry, so that the imaging of a three-dimensional scene after passing through the optical lens generates a pincushion distortion along a first direction and / or a pincushion distortion along a second direction, and the first direction is perpendicular to the second direction.

[0007] By providing at least one aspherical lens among the lenses of the optical lens for imaging, the aspherical lens can adjust the symmetry relationship of the imaging area of the optical lens to two-axis symmetry, that is, there are two axes of symmetry for the imaging area, and the two axes of symmetry extend along the first direction and the second direction respectively. When the optical lens including the aspherical lens images a three-dimensional scene, it generates a pincushion distortion along the first direction and / or a pincushion distortion along the second direction, which can exactly correct the stretching deformation generated when the edge objects of the three-dimensional scene are imaged. At the same time, the deformation along these two directions can keep the straight lines in the image horizontal and vertical and still remain straight lines, so that the pincushion distortion is not easily detected, and thus a better imaging is obtained.

[0008] In some embodiments, the aspherical lens includes an object side surface and an image side surface, and the object side surface and / or the image side surface is an aspherical surface. The aspherical surface satisfies the formula:

[0009]

[0010] where z is the sag of the optical surface; r is the radius height in the optical axis direction, where r 2 = x 2 + y 2 ; c is the radius of curvature; K is the conic constant; A i is the polynomial coefficient; E i is the power series in the x and y directions;

[0011]

[0012] Through the above formula, the coordinates of each position of the object side surface and the image side surface of the aspherical lens can be calculated, so as to design the required aspherical lens.

[0013] In some embodiments, the aspherical lens has two symmetry planes, one symmetry plane is parallel to the first direction, and the other symmetry plane is parallel to the second direction. Therefore, the aspherical lens can adjust the symmetry relationship of the imaging area of the optical lens to two-axis symmetry, so that the imaging of a three-dimensional scene after passing through the optical lens generates a pincushion distortion along the first direction and / or a pincushion distortion along the second direction.

[0014] In some embodiments, the non-rotationally symmetric lens is closer to the image side of the optical lens than the other lenses. The closer it is to the image side of the optical lens, the greater the work it undertakes in adjusting the optical path and the more important it is for the adjustment of the optical effect. When the lens closer to the image side of the optical lens is set as a non-rotationally symmetric lens, it is possible to achieve a better effect of correcting the stretching deformation generated when imaging the edge objects in a three-dimensional scene. Moreover, by setting the non-rotationally symmetric lens closer to the image side of the optical lens than the other lenses of the optical lens, the non-rotationally symmetric lens can correspondingly correct the aberration generated by the other lenses on its object side to obtain a better imaging effect.

[0015] In some embodiments, the optical lens causes the amount of pincushion distortion generated in the imaging in the first direction to gradually increase from the middle deformation position of the imaging field of view to the edge, and the optical lens causes the amount of pincushion distortion generated in the imaging along the second direction to gradually increase from the middle deformation position of the imaging field of view to the edge.

[0016] Since the stretching deformation of the imaging of a three-dimensional scene from the middle deformation position to the edge in the first direction and in the second direction gradually increases under a traditional optical lens with all lenses being rotationally symmetric lenses, therefore, by adjusting the non-rotationally symmetric lens, the optical lens including the non-rotationally symmetric lens causes the amount of pincushion distortion generated in the imaging in the first direction to gradually increase from the middle deformation position of the imaging field of view to the edge, and the optical lens causes the amount of pincushion distortion generated in the imaging along the second direction to gradually increase from the middle deformation position of the imaging field of view to the edge, so as to be able to correspondingly correct each position of the imaging to obtain better imaging.

[0017] In some embodiments, the optical lens causes the amount of pincushion distortion generated at the same position in the first direction and at different positions in the second direction of the imaging to be the same; the optical lens causes the amount of pincushion distortion generated at the same position in the second direction and at different positions in the first direction of the imaging to be the same, so that the degree of pincushion distortion of the optical lens for the imaging corresponds to the degree of stretching of the imaging by the rotationally symmetric lens, enabling the pincushion distortion of the optical lens to correspondingly correct each position of the imaging and ensuring that the straight lines in the corrected imaging can still be basically horizontal and vertical without obvious bending, meeting the general judgment criteria of users for distortion-free imaging, thereby obtaining better imaging.

[0018] In some embodiments, the optical aberration generated by the optical lens in the imaging along the first direction and / or along the second direction is not less than 3%, so as to be able to fully correct the stretching deformation generated by the imaging of the edge objects in a three-dimensional scene, minimize the influence of the deformation of the two-dimensional scene, and thus obtain better imaging quality.

[0019] In some embodiments, the TV distortion of the imaging along the first direction and the second direction generated by the optical lens is not greater than 1%. The TV distortion is small, and the bending deformation of the imaging of the optical lens is not obvious after correction, so that a good imaging effect can be obtained.

[0020] In some embodiments, the distance from the object side surface of the first lens to the image plane corresponding to the infinite distance of the object is the total length TTL of the lens group system, and the half length of the diagonal of the effective pixel area of the imaging plane of the lens group is ImgH, satisfying the condition: TTL / ImgH ≤ 1.50. When TTL / ImgH ≤ 1.50, it can be ensured that the total length TTL of the lens group system of the optical lens 10 is small, and the half length of the diagonal of the effective pixel area of the imaging plane of the lens group is large, namely ImgH. Thus, while obtaining a high imaging pixel, the total length TTL of the lens group system of the optical lens 10 is small, which is convenient for the application of the optical lens 10 in terminal devices such as mobile phones, and realizes the thinning of terminal devices such as mobile phones.

[0021] In some embodiments, the focal length of the optical lens is less than 20 mm. That is, the distance between the lens of the optical lens and the photosensitive element can be small, so that the total length of the lens group system of the optical lens can be small.

[0022] In some embodiments, the maximum field of view angle of the optical lens exceeds 100°. That is, the optical lens of the present application can be a wide-angle lens or an ultra-wide-angle lens, having a large shooting field of view.

[0023] In some embodiments, the other lenses are aspherical symmetric curved surfaces, and the image side and the object side of each lens satisfy the formula:

[0024]

[0025] where y is the sag height of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the vertex spherical curvature of the aspherical surface, K is the conic constant, a i is the aspherical coefficient, and ρ is the normalized axial coordinate.

[0026] Through the above formula, the coordinates of each position of the object side and the image side of the non-rotationally symmetric lens can be calculated, so as to design the required rotationally symmetric lens.

[0027] In a second aspect, a camera module is provided. The camera module includes a photosensitive element and an optical lens. The photosensitive element is located on the image side of the optical lens, and light is projected onto the photosensitive element after passing through the optical lens.

[0028] The optical image obtained after passing through the optical lens is converted into an electrical signal by the photosensitive element, and then subsequent steps such as image processing are performed, so that an image with better imaging quality can be obtained. Moreover, the optical lens of the present application corrects the stretching deformation of the edge objects in the three-dimensional scene, and can obtain better imaging quality. Therefore, the camera module of the present application can also achieve good imaging quality.

[0029] In some embodiments, the photosensitive element is square, the photosensitive element includes a vertical first side and a second side, the first direction is the same as the extending direction of the first side, and the second direction is the same as the extending direction of the second side.

[0030] Due to the symmetric characteristics of the two-axis symmetry of the imaging area of the optical lens of the present application, the shrinkage distortion of the imaging area is along the first direction and the second direction, and the first direction is parallel to the first side of the photosensitive element, and the second direction is parallel to the second side of the photosensitive element, so that the straight lines in the image after shrinkage distortion can remain horizontal and vertical, and the introduced distortion is not easily detected, thereby obtaining better shooting quality.

[0031] In a third aspect, a terminal is provided. The terminal includes an image processor and a camera module. The image processor is communicatively connected to the camera module. The camera module is configured to acquire image data and input the image data into the image processor, and the image processor is configured to process the output image data.

[0032] In the present application, the image processor is used to process the image data of the two camera modules to obtain better captured pictures or videos. Moreover, the optical lens of the present application corrects the stretching deformation of the edge objects in the three-dimensional scene, and can obtain better imaging quality. Therefore, the terminal of the present application can capture images with good imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the optical path principle when capturing the image of a three-dimensional scene through an optical lens.

[0034] Figure 2 It is a schematic diagram of the structure of a terminal according to an embodiment of the present application.

[0035] Figure 3 It is a schematic diagram of the structure of a terminal according to another embodiment of the present application.

[0036] Figure 4 is Figure 3 The schematic diagram of the imaging principle of the shown terminal.

[0037] Figure 5 It is a schematic diagram of the structure of a camera module according to an embodiment of the present application.

[0038] Figure 6 It is a schematic structural diagram of a non-rotationally symmetric lens of an optical lens according to an embodiment of the present application.

[0039] Figure 7 is Figure 6 A schematic cross-sectional view of the non-rotationally symmetric lens shown in the A-A direction.

[0040] Figure 8 is Figure 6 A schematic cross-sectional view of the non-rotationally symmetric lens shown in the B-B direction.

[0041] Figure 8a It is the symmetry characteristic of the imaging surface of a traditional optical lens.

[0042] Figure 8b It is the symmetry characteristic of the imaging surface of the optical lens of the present application.

[0043] Figure 9 It is a schematic diagram of the imaging simulation structure of the optical lens according to some embodiments of the present application on the imaging surface.

[0044] Figure 10 A schematic diagram showing the positional relationship between the optical lens and the object to be imaged in some embodiments of the present application.

[0045] Figure 11 is Figure 10 An imaging schematic diagram of the object to be imaged shown obtained by shooting with different optical lenses.

[0046] Figure 12 is Figure 9 An enlarged schematic diagram of position II in

[0047] Figure 13 It is a schematic structural diagram of an optical lens according to an embodiment of the present application. Specific embodiments

[0048] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings.

[0049] For ease of understanding, the technical terms involved in the present application will be explained and described first below.

[0050] Focal length (focal length, f), also known as the focal length, is a measure of the convergence or divergence of light in an optical system. It refers to the perpendicular distance from the optical center of a lens or a lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through the lens or the lens group. From a practical perspective, it can be understood as the distance from the center of the lens to the imaging plane. For a fixed-focus lens, the position of its optical center is fixed; for a zoom lens, the change in the optical center of the lens brings about a change in the focal length of the lens.

[0051] Positive refractive power, also known as positive dioptric power, indicates that the lens has a positive focal length and the effect of converging light rays.

[0052] Negative refractive power, also known as negative dioptric power, indicates that the lens has a negative focal length and the effect of diverging light rays.

[0053] Optical total length (total track length, TTL) refers to the total length from the end of the optical lens far from the imaging surface to the imaging surface, which is the main factor in forming the height of the camera.

[0054] The dispersion coefficient is the ratio of the difference in refractive indices of an optical material at different wavelengths, representing the degree of material dispersion.

[0055] Field of view (FOV), in an optical instrument, with the vertex of the optical instrument's lens as the vertex, the angle formed by the two edges of the maximum range through which the image of the measured object can pass through the lens is called the field of view angle. The size of the field of view angle determines the field of view of the optical instrument. The larger the field of view angle, the larger the field of view and the smaller the optical magnification.

[0056] The optical axis is a ray of light that vertically passes through the center of an ideal lens. When a ray of light parallel to the optical axis enters a convex lens, an ideal convex lens should be such that all the rays converge at a point behind the lens, and this point where all the rays converge is the focal point.

[0057] The object side, with the lens as the boundary, the side where the object to be photographed is located is the object side.

[0058] The image side, with the lens as the boundary, the side where the image of the object to be photographed is located is the image side.

[0059] The object side surface, the surface of the lens close to the object side is called the object side surface.

[0060] The image side surface, the surface of the lens close to the image side is called the image side surface.

[0061] Optical distortion refers to the difference between the display positions of points in a distorted image and their positions in an ideal system, focusing on the position offsets of each point at the microscopic level.

[0062] TV distortion refers to the height difference between the square side lines and the middle side lines, focusing on the distortion of a macroscopic rectangular image.

[0063] This application provides a terminal, which can be a mobile phone, a tablet computer, a computer, a camera, a camera or other devices with a photographing or video recording function in other forms. Please refer to Figure 2 , Figure 2The following is a schematic structural diagram of a terminal 1000 according to an embodiment of the present application. In this embodiment, the terminal 1000 is a mobile phone. In other embodiments, the terminal 1000 may be other devices with a shooting function in the form of a tablet, a camera, etc.

[0064] The terminal 1000 includes a camera module 100 and an image processor 200 communicatively connected to the camera module 100. The camera module 100 is configured to acquire image data and input the image data into the image processor 200 so that the image processor 200 processes the image data. Among them, the communication connection between the camera module 100 and the image processor 200 may include data transmission through electrical connection means such as wire connection, or may also be achieved through other means capable of data transmission such as optical cable connection or wireless transmission.

[0065] The function of the image processor 200 is to optimize the digital image signal through a series of complex mathematical algorithm operations, and finally transmit the processed signal to a display or store it in a memory. The image processor 200 may be an image processing chip or a digital signal processing (DSP) chip.

[0066] Figure 2 In the illustrated embodiment, the camera module 100 is disposed on the back of the terminal 1000 and is a rear camera of the terminal 1000. It can be understood that in some embodiments, the camera module 100 may also be disposed on the front of the terminal 1000 as a front camera of the terminal 1000. Both the front camera and the rear camera can be used for selfies or for the shooter to photograph other objects.

[0067] In some embodiments, there are multiple camera modules 100, and multiple means two or more. The multiple camera modules 100 can cooperate to achieve a better shooting effect. Figure 2 In the illustrated embodiment, there are two rear cameras of the terminal 1000, and both of the two camera modules 100 are communicatively connected to the image processor 200 to process the image data of the two camera modules 100 through the image processor 200 to obtain better captured pictures or videos.

[0068] It should be understood that Figure 2The installation position of the camera module 100 of the terminal 1000 in the illustrated embodiment is merely illustrative. In some other embodiments, the camera module 100 may also be installed at other positions on the mobile phone. For example, the camera module 100 may be installed in the middle or upper right corner of the back of the mobile phone; or, the camera module 100 may not be provided on the main body of the mobile phone, but on a component that is movable or rotatable relative to the mobile phone. For example, this component may extend, retract, or rotate from the main body of the mobile phone, etc. The present application does not make any limitation on the installation position of the camera module 100.

[0069] Please refer to Figure 3 and Figure 4 , Figure 3 which is a schematic structural diagram of a terminal according to another embodiment of the present application. Figure 4 is Figure 3 a schematic diagram of the imaging principle of the illustrated terminal. In some embodiments, the terminal 1000 further includes an analog-to-digital converter (also referred to as an A / D converter) 300. The analog-to-digital converter 300 is connected between the camera module 100 and the image processor 200. The analog-to-digital converter 300 is configured to convert the analog image signal generated by the camera module 100 into a digital image signal and transmit it to the image processor 200, and then the image processor 200 processes the digital image signal, and finally the image or video is displayed through the display screen or monitor.

[0070] In some embodiments, the terminal 1000 further includes a memory 400. The memory 400 is communicatively connected to the image processor 200. After the image processor 200 processes the image digital signal, the image is transmitted to the memory 400 so that the image can be retrieved from the memory at any time when it is needed to view the image later and displayed on the display screen. In some embodiments, the image processor 200 also compresses the processed image digital signal and then stores it in the memory 400 to save the space of the memory 400. It should be noted that Figure 3 is only a schematic structural diagram of an embodiment of the present application, and the positional structures of the camera module 100, the image processor 200, the analog-to-digital converter 300, and the memory 400 shown therein are only illustrative.

[0071] Please refer to Figure 4, the camera module 100 includes an optical lens 10 and an image sensor 20. The image sensor 20 is located on the image side of the optical lens 10. When the camera module 100 is operating, the light reflected by the scene to be imaged is projected onto the image sensor 20 after passing through the optical lens 10. Specifically, the working principle of the camera module 100 is as follows: The light L reflected by the object to be photographed generates an optical image through the optical lens 10 and is projected onto the surface of the image sensor 20. The image sensor 20 converts the optical image into an electrical signal, i.e., an analog image signal S1, and transmits the converted analog image signal S1 to the analog-to-digital converter 300 to be converted into a digital image signal S2 by the analog-to-digital converter 300 and sent to the image processor 200.

[0072] The image sensor 20 is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When irradiated by light, it generates electric charges, thus completing the conversion of optical signals into electrical signals. Optionally, the image sensor 20 can be any device capable of converting optical signals into electrical signals. For example, the image sensor 20 can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor device (CMOS).

[0073] The optical lens 10 affects the imaging quality and imaging effect. The optical lens 10 includes multiple lenses 11 arranged from the object side to the image side, and it mainly uses the refraction principle of the lenses 11 for imaging. Specifically, the light of the object to be imaged forms a clear image on the focal plane through the optical lens 10, and the image of the scene is recorded by the image sensor 20 located on the focal plane. There can be an air gap between adjacent lenses 11, or they can be arranged closely. Each lens 11 plays a different main role, and the best imaging quality is obtained through the cooperation between different lenses 11.

[0074] In some embodiments, the optical lens 10 further includes a diaphragm 12. The diaphragm 12 can be disposed on the object side of the multiple lenses 11 or between the lenses close to the object side among the multiple lenses 11. For example, the diaphragm can be located between the first lens and the second lens close to the object side, or between the second lens and the third lens close to the object side among the multiple lenses 11. The diaphragm 12 can be an aperture diaphragm, and the aperture diaphragm is used to limit the amount of incident light to change the brightness of the image.

[0075] In some embodiments, the optical lens 10 further includes an infrared filter 30, which is located between the photosensitive element 20 and the lens 11 of the optical lens 10. The light refracted by the optical lens 10 irradiates onto the infrared filter 30 and is transmitted to the photosensitive element 20 through the infrared filter 30. The infrared filter can filter out unnecessary light projected onto the photosensitive element 20, preventing the photosensitive element 20 from generating false colors or ripples, so as to improve its effective resolution and color reducibility.

[0076] Please refer to Figure 5 , Figure 5 The figure shows a schematic structural diagram of a camera module according to some embodiments of the present application. In some embodiments, the optical lens 10 further includes a lens barrel 10a. A plurality of lenses 11 of the optical lens 10 are fixed in the lens barrel 10a, and the plurality of lenses 11 fixed in the lens barrel 10a are coaxially arranged. In the embodiments of the present application, the plurality of lenses 11 are fixed in the lens barrel 10a, and the distance between each lens 11 is fixed. The optical lens 10 is a fixed-focus lens. In some other embodiments of the present application, the plurality of lenses 11 of the optical lens 10 can move relative to each other in the lens barrel 10a to change the distance between the plurality of lenses 11, so as to change the focal length of the optical lens 10 and achieve focusing of the optical lens 10. The infrared filter 30 can be fixed to one end of the lens barrel 10a of the optical lens 10 facing the image side.

[0077] The camera module 100 further includes structures such as a fixed base 50 (holder) and a circuit board 60.

[0078] The fixed base 50 includes a receiving cavity. The optical lens 10 is received in the receiving cavity of the fixed base 50 and is fixed to the cavity wall of the receiving cavity. The optical lens 10 is fixed relative to the fixed base 50 and cannot move relative to the fixed base 50. The circuit board 60 is fixed to the side of the fixed base 50 facing away from the optical lens 10. The circuit board 60 is used to transmit electrical signals. The circuit board 60 can be a flexible printed circuit (FPC) or a printed circuit board (PCB). Among them, the FPC can be a single-sided flexible board, a double-sided flexible board, a multi-layer flexible board, a rigid-flexible board or a flexible circuit board with a hybrid structure, etc. Other components included in the camera module 100 will not be elaborated one by one here. The infrared filter 30 can be fixed to the cavity wall of the fixed base 50 and is located between the optical lens 10 and the circuit board 60; or, it can also be supported and fixed above the circuit board 60 by a bracket.

[0079] The photosensitive element 20 is fixed to the circuit board 60 by bonding or patching. In addition, the photosensitive element 20 is located on the image side of the optical lens 10 and is arranged opposite to the optical lens 10, and the optical image generated by the optical lens 10 can be projected onto the photosensitive element 20. In some embodiments, the analog-to-digital converter 300, the image processor 200, the memory 400, etc. are also integrated on the circuit board 60 by bonding or patching, so that the communication connection between the photosensitive element 20, the analog-to-digital converter 300, the image processor 200, the memory 400, etc. is realized through the circuit board 60.

[0080] In some embodiments, the lens barrel 10a of the optical lens 10 and the fixed base 50 can be moved relative to the fixed base 50 to change the distance between the optical lens 10 and the photosensitive element 20. When the focal length of the optical lens 10 changes, the distance between the optical lens 10 and the photosensitive element 20 is adjusted accordingly, thereby ensuring the imaging quality of the camera module 100. For example, in some embodiments, the fixed base 50 includes a cavity wall of a receiving cavity provided with an internal thread, and the outer wall of the lens barrel 10a is provided with an external thread, and the lens barrel 10a is threadedly connected to the fixed base 50. The lens barrel 10a is driven to rotate by a driving member, so that the lens barrel 10a moves in an axial direction relative to the fixed base 50, so that the lens 11 of the optical lens 10 is close to or away from the photosensitive element 20. It is understandable that the lens barrel 10a can also be connected to the fixed base 50 in other ways, and realize the movement relative to the fixed base 50. For example, the lens barrel 10a is connected to the fixed base 50 through a slide rail.

[0081] In the present application, at least one lens 11 among the multiple lenses 11 of the optical lens 10 is a non-rotationally symmetric lens. The object side surface and / or image side surface of the non-rotationally symmetric lens are non-rotationally symmetric surfaces. Wherein, the object side surface and / or image side surface of the non-rotationally symmetric lens are non-rotationally symmetric surfaces, which means: the non-rotationally symmetric lens can be a lens with both the object side surface and the image side surface being non-rotationally symmetric surfaces; or, the non-rotationally symmetric lens is a lens with the object side surface being a rotationally symmetric surface and the image side surface being a non-rotationally symmetric surface; or, the non-rotationally symmetric lens is a lens with the object side surface being a non-rotationally symmetric surface and the image side surface being a rotationally symmetric surface. Wherein, the rotationally symmetric surface can be obtained by linear rotation, while the non-rotationally symmetric surface cannot be obtained by linear rotation. Please refer to Figure 6 , Figure 7 and Figure 8 , Figure 6 The above is a schematic diagram of the structure of a non-rotationally symmetric lens of an optical lens 10 according to an embodiment of the present application. Figure 6 The X direction shown in FIG. 1 is the first direction, and the Y direction is the second direction. Figure 7 for Figure 6 The schematic cross-sectional view of the non-rotationally symmetric lens along the AA direction is shown, wherein the cross-sectional view AA is parallel to the X direction and passes through the optical axis of the lens;Figure 8 As shown in Figure 6 FIG. 2 is a schematic cross-sectional view of the non-rotationally symmetric lens along the B-B direction, wherein the cross-section B-B is parallel to the Y direction and passes through the optical axis of the lens. It can be seen from the figure that the cross-section A-A of the non-rotationally symmetric lens obtained along the A-A direction is different from the cross-section B-B of the non-rotationally symmetric lens obtained along the B-B direction, that is, the non-rotationally symmetric lens cannot be obtained by planar rotation. In this embodiment, the lenses on both sides of the non-rotationally symmetric lens in the A-A direction are symmetric, and the lenses on both sides of the non-rotationally symmetric lens in the B-B direction are symmetric. It can also be said that in this embodiment, the non-rotationally symmetric lens has two symmetry planes, one symmetry plane is parallel to the first direction and is the plane where the cross-section B-B is located; the other symmetry plane is parallel to the second direction and is the plane where the cross-section A-A is located. It can be understood that in some other embodiments, the lenses on both sides of the non-rotationally symmetric lens in the A-A direction may also be asymmetric, and the lenses on both sides of the non-rotationally symmetric lens in the B-B direction may also be asymmetric.

[0082] The non-rotationally symmetric lens can cause the imaging of a three-dimensional scene after passing through the optical lens 10 including the non-rotationally symmetric lens to generate a contraction distortion along the first direction and / or a contraction distortion along the second direction. Wherein, the first direction is perpendicular to the second direction. In some embodiments, the photosensitive element 20 is square, and the square photosensitive element 20 includes a first side and a second side that are perpendicular to each other, wherein the first direction is the same as the extending direction of the first side, and the second direction is the same as the extending direction of the second side. When imaging a three-dimensional scene, especially when imaging a three-dimensional scene with a wide-angle lens or an ultra-wide-angle lens, the edge objects of the three-dimensional scene are more likely to produce stretching deformation. The edge objects of the three-dimensional scene refer to the objects located at the edge of the field of view of the optical lens 10 when shooting the three-dimensional scene. For example, when taking a group photo, the people located at the edge of the field of view of the optical lens 10. In the embodiment of the present application, the imaging after passing through the optical lens 10 including the non-rotationally symmetric lens can generate a contraction distortion along the first direction and / or a contraction distortion along the second direction, which can correct the stretching deformation generated by the edge objects of the three-dimensional scene, thereby obtaining high-quality imaging.

[0083] By providing at least one non-rotationally symmetric lens in the lenses of the optical lens for imaging. By the non-rotationally symmetric lens, the symmetry characteristic of the imaging area of the optical lens is changed from the central rotational symmetry characteristic to the two-axis symmetry characteristic. Specifically, please refer to Figure 8a and Figure 8b , Figure 8a FIGS. 3 and 4 show the symmetry characteristics of the imaging surface of a conventional optical lens; Figure 8bThis is the symmetry characteristic of the imaging surface of the optical lens 10 of the present application. Each lens of a traditional optical lens is a rotationally symmetric lens. The imaging area of a traditional optical lens is an imaging circle, that is, its imaging area is circular, and the symmetry characteristic of the imaging circle is central rotational symmetry. Applying a traditional lens makes the direction of the shrinkage distortion generated by imaging shrink from all directions towards the center of the imaging circle (as shown by the arrow directions in Figure 8a . However, the imaging area of the optical lens 10 of the present application is square, and its symmetry characteristic is two-axis symmetry, that is, there are two symmetry axes of the imaging area, and the two symmetry axes extend along the first direction and the second direction respectively. Applying the optical lens 10 makes the direction of the shrinkage distortion generated by imaging shrink along the first direction and / or along the second direction (as shown by the arrow directions in Figure 8b ). The introduction of non-rotationally symmetric lenses can correct the stretching deformation generated in the imaging of objects at the edge of a three-dimensional scene in the first direction and / or the second direction, resulting in better imaging quality. For example, please refer to Figure 9 , Figure 9 shows a schematic diagram of the imaging simulation structure of the optical lens 10 of the present application on the imaging surface. Among them, the solid grid a is the structure to be imaged, and this structure is a planar structure. The grid formed by connecting "X" in the figure is the imaging simulation diagram of the solid grid a after passing through the optical lens 10. It can be seen from the figure that when imaging through the optical lens 10 including at least one non-rotationally symmetric lens, the optical lens 10 can cause the imaging to generate shrinkage distortion along the first direction and along the second direction. Therefore, when the optical lens 10 is applied to photographing a three-dimensional scene, the application of non-rotationally symmetric lenses in the optical lens 10 enables the shrinkage distortion along the first direction generated by imaging to correct the stretching deformation generated in the first direction during the imaging of objects at the edge of the three-dimensional scene, and the optical lens 10 enables the shrinkage distortion along the second direction generated by imaging to correct the stretching deformation generated in the second direction during the imaging of objects at the edge of the three-dimensional scene, and can weaken the stretching deformation generated in the imaging of objects at the edge of the three-dimensional scene when photographing the three-dimensional scene. At the same time, due to the two-axis symmetry characteristic of the imaging area of the optical lens 10 of the present application, the shrinkage distortion of the imaging area is along the first direction and the second direction, and the first direction is parallel to the first side of the photosensitive element 20, and the second direction is parallel to the second side of the photosensitive element 20. Thus, it can be ensured that the straight lines in the imaged image after shrinkage distortion can remain horizontal and vertical, and the introduced distortion is not easily detected, thereby obtaining better photographing quality.

[0084] For example, please refer to Figure 10 and Figure 11 , Figure 10 shows a schematic diagram of the positional relationship between the optical lens and the object to be imaged in some embodiments of the present application. Figure 11 As shown is Figure 10Schematic diagram of images obtained by photographing the object to be imaged through different optical lenses. Among them, the objects to be imaged are object A to be imaged, object B to be imaged, object C to be imaged, object D to be imaged, and object E to be imaged. The object A to be imaged is facing the optical lens and is located at the middle position of the field of view of the optical lens. Object B to be imaged and object C to be imaged are respectively located at the edges of the field of view in the first direction of the optical lens and are respectively located on both sides of object A to be imaged. Object D to be imaged and object E to be imaged are respectively located at the edges of the field of view in the second direction of the optical lens and are respectively located on both sides of object A to be imaged.

[0085] Figure 11 The dotted lines in the figure show the images obtained on the photosensitive element 20 when photographing object A to be imaged, object B to be imaged, object C to be imaged, object D to be imaged, and object E to be imaged through an existing ordinary optical lens. Among them, the image obtained for object A to be imaged is image A1, the image obtained for object B to be imaged is image B1, the image obtained for object C to be imaged is image C1, the image obtained for object D to be imaged is image D1, and the image obtained for object E to be imaged is image E1. The solid lines show the images obtained on the photosensitive element 20 when photographing object A to be imaged, object B to be imaged, object C to be imaged, object D to be imaged, and object E to be imaged through the optical lens 10 in this embodiment. Among them, the image obtained for object A to be imaged is image A2, the image obtained for object B to be imaged is image B2, the image obtained for object C to be imaged is image C2, the image obtained for object D to be imaged is image D2, and the image obtained for object E to be imaged is image E2. It can be easily seen from the figure that when photographing object B to be imaged, object C to be imaged, object D to be imaged, and object E to be imaged located at the edge of the field of view through an ordinary optical lens, stretching distortion will occur. Since the optical lens 10 of this embodiment enables the image to generate a contraction distortion in the first direction, which can correct the stretching distortion generated in the first direction when imaging the object at the edge of the three-dimensional scene, and enables the image to generate a contraction distortion in the second direction, which can correct the stretching distortion generated in the second direction when imaging the object at the edge of the three-dimensional scene, therefore, the stretching distortion of the object at the edge of the three-dimensional scene can be appropriately corrected, thereby obtaining the image shown by the solid line.

[0086] In some other embodiments, when the three-dimensional scene is imaged and mainly generates stretching deformation in the first direction (such as Figure 6 the X direction in the figure), a non-rotationally symmetric lens can be designed so that the optical lens 10 including the non-rotationally symmetric lens can enable the three-dimensional scene imaging to generate a contraction distortion in the first direction. Among them, the contraction distortion in the first direction generated by the optical lens 10 including the non-rotationally symmetric lens when imaging the three-dimensional scene can correct the stretching distortion generated in the first direction when imaging the object at the edge of the three-dimensional scene, thereby obtaining a better image. Or, when the three-dimensional scene is imaged and mainly generates stretching deformation in the second direction (such as Figure 6When there is a tensile deformation in the Y direction (in the middle), a non-rotationally symmetric lens can be designed so that the optical lens 10 including the non-rotationally symmetric lens can cause the imaging of a three-dimensional scene to produce a contraction distortion in the second direction. Among them, the contraction distortion in the second direction generated by the optical lens 10 including the non-rotationally symmetric lens can correct the tensile deformation generated in the second direction during the imaging of the three-dimensional scene, thereby obtaining better imaging.

[0087] Please refer to Figure 9 and Figure 12 , Figure 12 as shown in Figure 9 is an enlarged schematic view of position II in the middle. The imaging of a three-dimensional scene under a traditional optical lens with all rotationally symmetric lenses shows that the tensile deformation from the middle deformation position to the edge in the first direction gradually increases. Among them, the middle deformation position refers to the position where the deformation starts in the middle area of the imaging. In the embodiment of the present application, by introducing rotationally symmetric lenses, the amount of deformation of the contraction distortion generated by the optical lens 10 during imaging in the first direction gradually increases from the middle deformation position to the edge of the imaging field of view, that is, L5 is greater than L6, and L7 is greater than L8; the amount of deformation of the contraction distortion generated by the optical lens 10 causing the imaging in the second direction gradually increases from the middle deformation position to the edge of the imaging field of view, that is, L1 is greater than L3, and L2 is greater than L4. Therefore, the optical lens 10 including non-rotationally symmetric lenses can perform corresponding corrections on each position of the imaging to obtain better imaging.

[0088] In the embodiment of the present application, the amount of deformation of the contraction distortion generated by the optical lens 10 causing the imaging at the same position in the first direction and different positions in the second direction is basically the same, that is, L5 is basically equal to L7, and L6 is basically equal to L8; the amount of deformation of the contraction distortion generated by the optical lens 10 causing the imaging at the same position in the second direction and different positions in the first direction is basically the same, that is, L1 is basically equal to L2, and L3 is basically equal to L4. Therefore, the degree of contraction of the imaging by the optical lens 10 corresponds to the degree of stretching of the imaging by the rotationally symmetric lens, so that the contraction distortion of the optical lens 10 can perform corresponding corrections on each position of the imaging, and can ensure that the straight lines in the corrected imaging can still be basically horizontal and vertical without obvious bending, meeting the general judgment criteria of users for distortion-free imaging, thereby obtaining better imaging.

[0089] In some embodiments, among the image side and the object side of the non-rotationally symmetric lens, at least the image side of the non-rotationally symmetric lens is a non-rotationally symmetric surface. Since the image side is closer to the photosensitive element, the degree of convergence of light on the image side is better than that on the object side. When the image side is set as a non-rotationally symmetric surface, compared with only setting the object side as a non-rotationally symmetric surface, it can achieve a better effect of correcting the tensile deformation generated during the imaging of the edge objects in the three-dimensional scene.

[0090] In some embodiments, the non-rotationally symmetric lens is closer to the image side of the optical lens than other lenses of the optical lens. The closer it is to the image side of the optical lens, the greater the work it undertakes in adjusting the optical path, and the more important it is for adjusting the optical effect. When the lens closer to the image side of the optical lens is set as a non-rotationally symmetric lens, it is possible to achieve a better effect of correcting the stretching deformation generated when imaging an object at the edge of a three-dimensional scene. Moreover, making the non-rotationally symmetric lens closer to the image side of the optical lens than other lenses of the optical lens enables the non-rotationally symmetric lens to correspondingly correct the aberrations generated by other lenses on its object side, so as to obtain a better imaging effect.

[0091] In this application, the object side or the image side of multiple lenses 11 of the optical lens 10 can be spherical or aspherical. In some embodiments of this application, all the lenses 11 of the optical lens 10 are aspherical lenses, and the object side and / or the image side of the aspherical lens is / are free-form surfaces that are aspherical. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the edge of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberrations that occur during imaging as much as possible, thereby improving the imaging quality.

[0092] In an embodiment of this application, the non-rotationally symmetric surface of the non-rotationally symmetric lens is also a free-form surface that is aspherical, and the non-rotationally symmetric surface satisfies the formula:

[0093]

[0094] where z(x, y) is the sag of the optical surface; k is the conic constant; c is the radius of curvature; r is the radius height in the optical axis direction, where r2 = x2 + y2; Ai is the polynomial coefficient; Ei is the power series in the x and y directions. Specifically,

[0095]

[0096] In an embodiment of this application, the object side and the image side of other lenses 11 of the multiple lenses 11 of the optical lens 10 except the non-rotationally symmetric lens are both rotationally symmetric free-form surfaces. Among them, the rotationally symmetric free-form surface satisfies the formula:

[0097]

[0098] where z(x, y) is the sag of the optical surface; k is the conic constant; c is the radius of curvature; r is the radius height in the optical axis direction; r 2 = x 2 + y 2 ; α iis the polynomial coefficient; ρ i is the normalized radial coordinate.

[0099] Through the above relationships, the lens 11 with different aspherical surfaces can be obtained, so that different lenses 11 can achieve different optical effects, and thus a good shooting effect can be achieved through the cooperation of different aspherical lenses 11.

[0100] In some embodiments of the present application, the optical lens 10 causes the optical distortion along the first direction (such as Figure 11 the X direction in Figure 11 and along the second direction (such as Figure 11 the Y direction in Figure 11 of the imaging to be not less than 3%, so as to fully correct the stretching deformation generated by the imaging of the edge objects in the three-dimensional scene, and to minimize the influence of the two-dimensional scene deformation as much as possible, so as to obtain better imaging quality. Since the optical lens 10 with non-rotationally symmetric lenses can change the symmetry characteristic of the imaging area of the optical lens 10 to two-axis symmetry, causing the first direction and the second direction of the imaging to have shrinkage distortion, so that the optical lens 10 including non-rotationally symmetric lenses can correct the stretching deformation at each position of the imaging accordingly. Since the symmetry characteristic of the imaging area of the optical lens 10 is two-axis symmetry, there will be no obvious bending deformation at the edge after the imaging is corrected, ensuring that the TV distortion is small, so as to obtain better imaging quality. In this embodiment, the TV distortion of the optical lens is not more than 1%, that is, the TV distortion of the optical lens 10 along the first direction (such as Figure 11 the X direction in Figure 11 and along the second direction (such as

[0101] In some embodiments of the present application, the total length TTL of the lens group system of the optical lens 10 and the half length of the diagonal of the effective pixel area of the imaging surface of the lens group are ImgH, satisfying the condition: TTL / ImgH ≤ 1.50. When TTL / ImgH ≤ 1.50, it can ensure that the total length TTL of the lens group system of the optical lens 10 is small, and the half length of the diagonal of the effective pixel area of the imaging surface of the lens group is ImgH is large. Thus, while obtaining a high imaging pixel, the total length TTL of the lens group system of the optical lens 10 is small, which is convenient for the application of the optical lens 10 in terminal devices such as mobile phones, realizing the thinning of terminal devices such as mobile phones. In some embodiments, TTL / ImgH can also be greater than 1.50. However, when TTL / ImgH is greater than 1.50, the total length TTL of the lens group system of the optical lens is long, which is not suitable for applications in terminals such as mobile phones and tablets that require thinning as much as possible.

[0102] In some embodiments, the focal length of the optical lens 10 can be less than 20 mm, that is, the distance between the lens 11 of the optical lens 10 and the photosensitive element 20 can be relatively small, so that the total length of the lens group system of the optical lens can be relatively small. In some embodiments, the maximum field of view angle of the optical lens 10 can exceed 100°, that is, the optical lens 10 can be a wide-angle lens or an ultra-wide-angle lens. By providing at least one non-rotationally symmetric lens among the multiple lenses 11 of the optical lens 10, the stretching deformation generated at the edge of the imaging can be reduced, so as to ensure that the photos taken by the wide-angle lens or the ultra-wide-angle lens can also have a better imaging effect.

[0103] Please refer to Figure 13 , Figure 13 FIG. shows a schematic structural diagram of an optical lens 10 according to an embodiment of the present application. In this embodiment, the optical lens 10 includes six lenses 11 arranged in sequence from the object side to the image side. There is an air gap between adjacent lenses 11. An image with a better imaging effect is formed through the cooperation of the six lenses 11. It can be understood that in some other embodiments, the number of lenses 11 of the optical lens 10 can also be other numbers. For example, the number of lenses 11 of the optical lens 10 can be five or seven. The six lenses 11 are, in sequence from the object side to the image side, a first lens 111, a second lens 112, a third lens 113, a fourth lens 114, a fifth lens 115, and a sixth lens 116, and each lens 11 is coaxially arranged. It can be understood that the multiple lenses 11 of the present application are all lenses 11 with positive refractive power or negative refractive power. When a plane mirror is inserted between the multiple lenses 11, the plane mirror is not counted as a lens 11 of the optical lens of the present application. For example, when a plane mirror is inserted between the fourth lens 114 and the fifth lens 115, the plane mirror cannot be counted as the fifth lens 11 of the embodiment of the present application. In this embodiment, the aperture stop 12 is provided between the second lens 112 and the third lens 113.

[0104] Among them, the first lens 111 has positive refractive power, its object side surface is concave at the paraxial region, and its image side surface is convex at the paraxial region; the second lens 112 has negative refractive power, its object side surface is convex at the paraxial region, and its image side surface is convex at the paraxial region; the third lens 113 has positive refractive power, its object side surface is convex at the paraxial region, and its image side surface is concave at the paraxial region; the fourth lens 114 has positive refractive power, its object side surface is concave at the paraxial region, and its image side surface is concave at the paraxial region; the fifth lens 115 has negative refractive power, its object side surface is concave at the paraxial region, and its image side surface is concave at the paraxial region; the sixth lens 116 has positive refractive power, its object side surface is concave at the paraxial region, and its image side surface is convex at the paraxial region. Among them, the object side surface and the image side surface of the first lens 111, the second lens 112, the third lens 113, the fourth lens 114, and the fifth lens 115 are all rotationally symmetric free-form surfaces, and the object side surface and the image side surface of the sixth lens 116 are both non-rotationally symmetric free-form surfaces.

[0105] In the embodiments of the present application, the different lenses 11 of the optical lens 10 can play different roles respectively, so that an optical lens 10 with good imaging quality can be obtained through the cooperation of the lenses 11. Specifically, in this embodiment, the first lens 111 has a positive refractive power and can serve to increase the field angle; the second lens 112 has a negative refractive power and can serve to converge light; both the second lens 112 and the fourth lens 114 are meniscus structures and can form a quasi-Gauss structure, which helps to improve the aberration of the optical lens 10 to improve the imaging quality of the optical lens 10; the second lens 112 cooperates with the third lens 113 to correct chromatic aberration; the fifth lens 115 has a negative refractive power and is used to expand the light beam to increase the imaging image height; the sixth lens 116 can increase the system light transmission and correct distortion. It should be noted that only the roles played by the lenses 11 in this embodiment are given here. In other embodiments of the present application, the lenses 11 can play other roles, which are not limited here.

[0106] Satisfying the above distribution of positive and negative refractive powers is beneficial to slowing down the deflection angle of light, so as to achieve the purpose of increasing the field angle by using the retrofocus principle. Especially compared with the telephoto structure in which the first lens uses a positive lens, making the first lens have a negative refractive power can make it easier for the system to increase the field angle.

[0107] In this embodiment, the first lens 111, the second lens 112, the third lens 113, the fourth lens 114, the fifth lens 115 and the sixth lens 116 are all made of resin, and the infrared filter 30 is made of glass. Resin materials are easy to mold; glass materials have a small coefficient of thermal expansion and are more stable in performance under large temperature differences. Moreover, glass materials have a large refractive index range, and lenses with a thinner thickness and better imaging quality can be obtained according to needs. In some embodiments, the lenses 11 can also be made of glass. Considering the manufacturing cost, efficiency and optical effects, the specific application materials of different lenses 11 are reasonably matched according to needs.

[0108] According to the above relationship formula, the design parameters of the lenses of the optical lens in this embodiment are shown in Tables 1, 2 and 3 below.

[0109] Table 1 Design parameters of the optical lens 10

[0110]

[0111]

[0112] Among them, S1 represents the object side of the first lens 111, S2 represents the image side of the first lens 111, S3 represents the object side of the second lens 112, S4 represents the image side of the second lens 112, STO represents the stop 12, S5 represents the object side of the third lens 113, S6 represents the image side of the third lens 113, S7 represents the object side of the fourth lens 114, S8 represents the image side of the fourth lens 114, S9 represents the object side of the fifth lens 115, S 10 represents the image side of the fifth lens 115, S 11 represents the object side of the sixth lens 116, S 12 represents the image side of the sixth lens 116, S 13 represents the object side of the infrared filter 30, S 14 represents the image side of the infrared filter 30. It should be noted that in this application, the meanings represented by symbols such as S1, S2, S3, S4, STO, S5, S6, S7, S8, S9, S 10 , S 11 , S 12 , S 13 , S 14 are all the same. They will not be elaborated again when they appear later.

[0113] Table 2 Design parameters of the optical lens 10

[0114]

[0115]

[0116] Among them, K represents the conic coefficient, and symbols such as α1, α2, α3, α4, α5, α6, α7, α8, α9, α 10 , α 11 , α 12 , α 13 , α 14 , α 15 , α 16 represent polynomial coefficients.

[0117] By substituting the above parameters into the formula satisfied by the rotationally symmetric freeform surface:

[0118] the first lens 111, the second lens 112, the third lens 113, the fourth lens 114, and the fifth lens 115 can be designed.

[0119] Table 3 Design parameters of the optical lens 10

[0120] Parameter S11 S12 K -1.0181 -7.9092 <![CDATA[A1]]> 6.6144 0.1746 <![CDATA[A2]]> 6.5810 0.1039 <![CDATA[A3]]> -3.4192 -0.5776 <![CDATA[A4]]> -1.6785 -0.0347 <![CDATA[A5]]> -1.7459 -0.2677 <![CDATA[A6]]> 0.4120 -0.1045 <![CDATA[A7]]> 0.4520 0.0886 <![CDATA[A8]]> 1.5625 0.3330 <![CDATA[A9]]> 1.5491 0.3683 <![CDATA[A 10 > 0.3978 0.0766 <![CDATA[A 11 > -0.9257 -0.2685 <![CDATA[A 12 > 0.0178 -0.1608 <![CDATA[A 13 > -0.1031 -0.1197 <![CDATA[A 14 > 0.0388 -0.0184

[0121] By substituting the above parameters into the formula satisfied by the non-rotationally symmetric freeform surface:

[0122]

[0123]

[0124] the sixth lens 116 can be designed and obtained.

[0125] The optical lens 10 designed according to the above parameters has the basic parameters shown in Table 4.

[0126] Table 4 Basic parameters of the optical lens 10

[0127] Focal length f 3.05 mm Aperture F value 2.2 FOV 120° Overall optical length TTL 5.564 mm Optical distortion in the first direction -9.5％ Optical distortion in the second direction -4.5％ TV distortion in the first direction 0.2％ TV distortion in the second direction 0.1％

[0128] In the embodiment of the present application, the focal length of the optical lens 10 is 3.05 mm, the overall optical length TTL is 5.564 mm, and ImgH is 5.186 mm, that is, in this embodiment, TTL / ImgH≤1.50. When TTL / ImgH≤1.50, while achieving a relatively high imaging pixel, the total length TTL of the lens group system of the optical lens 10 is relatively small, which is convenient for the application of the optical lens 10 in terminal devices such as mobile phones, and realizes the thinning of terminal devices such as mobile phones. The FOV of the optical lens 10 is 120°, that is, the optical lens 10 in this embodiment is a wide-angle lens. The optical distortions in the first direction and the second direction of the optical lens 10 are both greater than 3%, that is, the shrinkage distortion in the first direction and the shrinkage distortion in the second direction generated by the imaging of the objects at the edge of the three-dimensional scene after passing through the optical lens 10 can both be greater than 3%, so as to produce a better correction effect on the stretching deformation generated by the imaging of the objects at the edge of the three-dimensional scene, and thus obtain better imaging quality. The TV distortion of the optical lens 10 is less than 1%, so as to ensure that there is no obvious bending deformation at the edge of the obtained image after correction, and thus obtain better imaging quality. It should be noted that only one embodiment of the optical lens 10 is given in the present application, but there are other embodiments of the optical lens 10 in the present application to correct the stretching deformation generated when imaging the objects at the edge of the three-dimensional scene, so as to obtain better imaging.

[0129] In this application, by providing at least one aspherical lens in the lens 11 of the optical lens 10 for imaging, the aspherical lens can adjust the symmetry relationship of the lens imaging plane, changing from a rotationally symmetric relationship centered to a two-axis symmetric relationship, causing the optical lens 10 to produce a contraction distortion along the first direction and / or a contraction distortion along the second direction when imaging an object at the edge of a three-dimensional scene. The contraction distortion along the first direction and / or the contraction distortion along the second direction generated by the optical lens 10 can exactly correct the stretching deformation generated when imaging an object at the edge of a three-dimensional scene, thereby obtaining a better image. At the same time, the deformations along these two directions can keep the straight lines in the image horizontal and vertical and still remain straight lines, making it difficult to detect the contraction distortion, and thus obtaining a better image.

[0130] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. An optical lens, characterized in that, Comprising a plurality of lenses arranged from the object side to the image side, at least one of the plurality of lenses being a non-rotationally symmetric lens for adjusting the symmetry characteristic of the imaging area of the optical lens to two-axis symmetry, such that the imaging of a three-dimensional scene through the optical lens produces a contraction distortion in a first direction and / or a contraction distortion in a second direction, the first direction being perpendicular to the second direction; The optical lens causes the imaging to produce the same amount of deformation of the contraction distortion at the same position in the first direction and at different positions in the second direction; The optical lens causes the imaging to produce the same amount of deformation of the contraction distortion at the same position in the second direction and at different positions in the first direction; The optical lens causes the optical distortion produced by the imaging in the first direction and / or in the second direction to be not less than 3%; 2. The optical lens according to claim 1, characterized in that, The non-rotationally symmetric lens includes an object side surface and an image side surface, the object side surface and / or the image side surface being a non-rotationally symmetric surface, the non-rotationally symmetric surface satisfying the formula: Among them, z is the sag of the optical surface; r is the radius height in the optical axis direction, where r 2 = x 2 + y 2 ; c is the radius of curvature; K is the conic coefficient; A i is the polynomial coefficient; E i is the power series in the x and y directions; 3. The optical lens according to claim 1 or 2, characterized in that, The non-rotationally symmetric lens has two symmetric planes, one of the symmetric planes being parallel to the first direction and the other symmetric plane being parallel to the second direction.

4. The optical lens according to claim 1, wherein, The non-rotationally symmetric lens is closer to the image side of the optical lens than the other lenses.

5. The optical lens according to claim 1, characterized in that, The optical lens causes the amount of deformation of the contraction distortion in the first direction of the imaging to gradually increase from the middle deformation position to the edge of the imaging field of view, and the optical lens causes the amount of deformation of the contraction distortion in the second direction of the imaging to gradually increase from the middle deformation position to the edge of the imaging field of view.

6. The optical lens according to claim 1, characterized in that The optical lens causes the TV distortion produced by the imaging in the first direction and / or in the second direction to be not greater than 1%; 7. The optical lens according to claim 1, characterized in that, When the distance from the object side surface of the first lens to the image surface corresponding to the object at infinity is the total length TTL of the lens group system, and the half length of the diagonal of the effective pixel area of the imaging surface of the lens group is ImgH, the condition is satisfied: TTL / ImgH ≤ 1.

50.

8. The optical lens according to claim 1, wherein The focal length of the optical lens is less than 20 mm.

9. The optical lens according to claim 1, wherein The maximum field of view angle of the optical lens exceeds 100°.

10. The optical lens according to claim 1, characterized in that, The other lenses of the optical lens except the non-rotationally symmetric lens are rotationally symmetric lenses, and the object side surface and / or the image side surface of the rotationally symmetric lens is a rotationally symmetric free-form surface, the rotationally symmetric free-form surface satisfying the formula: where y is the sag of the aspheric surface, r is the radial coordinate of the aspheric surface, c is the vertex spherical curvature of the aspheric surface, K is the conic constant, a i is the aspheric coefficient, and ρ is the normalized axial coordinate.

11. A camera module, characterized in that, Comprising a photosensitive element and an optical lens according to any one of claims 1-10, the photosensitive element being located on the image side of the optical lens, and light passing through the optical lens is projected onto the photosensitive element.

12. The camera module according to claim 11, wherein, The photosensitive element is square, the photosensitive element includes a first side and a second side that are perpendicular, the first direction is the same as the extending direction of the first side, and the second direction is the same as the extending direction of the second side.

13. A terminal, characterized in that, Comprising an image processor and a camera module according to claim 11 or 12, the image processor is communicatively connected to the camera module, the camera module is used to acquire image data and input the image data into the image processor, and the image processor is used to process the output image data.

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