Optical lens, camera and electronic equipment

Abstract

The embodiment of the invention discloses an optical lens, a camera and electronic equipment. The optical lens, the camera and the electronic equipment have the characteristics of miniaturization, low cost, high imaging performance and relatively high thermal stability. The optical lens comprises four lens groups, the number of adopted lens groups is small on the premise that the function of the optical lens is achieved, and miniaturization can be achieved conveniently. At least one lens group in the optical lens comprises an even number of aspheric plastic lenses. On one hand, the aspheric plastic lenses are adopted, so that the cost is reduced, and meanwhile, the better imaging quality can be ensured; and on the other hand, the design of an even number of aspheric plastic lenses in the same lens group is helpful for improving the thermal stability of the optical lens, that is, the influence of the ambient temperature on the imaging quality is reduced, and good imaging in an environment of-30 DEG C to 70 DEG C can be ensured.

Description

Technical Field

[0001] This application relates to the field of optical imaging, and particularly to an optical lens, a camera, and an electronic device. Background Art

[0002] As a window for information input, surveillance lenses play an irreplaceable role in fields such as intelligent transportation, intelligent home, and intelligent security. In particular, in open scenarios, in order to cover all aspects of a large-scale scene, a pan-tilt-zoom camera is required for shooting and tracking. The pan-tilt-zoom camera integrates a pan-tilt system, a communication system, a camera system, etc., including parts such as motor control, image transmission, and imaging, and is usually large in volume and weight.

[0003] Moreover, in recent years, people's demand for the resolution and high-power zoom of lenses has been increasing day by day, resulting in an increasing proportion of the space occupied by lenses, which further exacerbates the bulkiness of the pan-tilt-zoom camera and is not conducive to the miniaturization design and cost control of the pan-tilt-zoom camera. Therefore, there is an urgent need for a lens that combines miniaturization, low cost, high imaging performance, and high thermal stability. Summary of the Invention

[0004] Embodiments of this application provide an optical lens, a camera, and an electronic device, which have the characteristics of miniaturization, low cost, high imaging performance, and high thermal stability.

[0005] In a first aspect, embodiments of this application provide an optical lens, which includes a first lens group, a second lens group, a third lens group, and a fourth lens group arranged along the optical axis from the object side to the image side. The positions of the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis. The first lens group, the third lens group, and the fourth lens group have positive optical powers, and the second lens group has a negative optical power. At least one lens group in the optical lens includes an even number of aspherical plastic lenses.

[0006] In this embodiment, the optical lens includes 4 lens groups. With a relatively small number of lens groups while ensuring the realization of the functions of the optical lens, it is convenient to achieve miniaturization. At least one lens group in the optical lens includes an even number of aspherical plastic lenses. On the one hand, using some aspherical plastic lenses can reduce costs while ensuring good imaging quality; on the other hand, designing an even number of aspherical plastic lenses in the same lens group helps to improve the thermal stability of the optical lens, that is, reduces the influence of the ambient temperature on the imaging quality, and can ensure good imaging in an environment of -30°C to 70°C.

[0007] In some possible embodiments, taking two aspherical plastic lenses in a lens group as an example, the signs of the optical powers of the two aspherical plastic lenses are opposite. Further, the absolute values of the optical powers of the two aspherical plastic lenses are similar or equal. In this way, as the temperature changes, the total optical power of the lens group remains as constant as possible, which is beneficial to reducing the influence of the ambient temperature on the performance stability of the lens and further improving the thermal stability of the entire lens. For example, the two aspherical plastic lenses are respectively denoted as the first aspherical plastic lens and the second aspherical plastic lens. represents the optical power of the first aspherical plastic lens. represents the optical power of the second aspherical plastic lens, then it satisfies In a possible scenario, that is In another possible scenario, Among the two aspherical plastic lenses, the one with the larger absolute value of the optical power is denoted as the first aspherical plastic lens, and the one with the smaller absolute value of the optical power is denoted as the second aspherical plastic lens, then It should be understood that the present application does not limit the specific value of the preset value, and in practical applications, the preset value can be flexibly set according to actual needs. For example, the preset value is 5, that is it is considered that the absolute values of the optical powers of the two aspherical plastic lenses are similar or equal.

[0008] In some possible embodiments, each lens group in the optical lens includes at least one glass lens, which is beneficial to improving the zoom ability, imaging quality and thermal stability of the optical lens.

[0009] In some possible embodiments, each glass lens in the optical lens is a spherical glass lens, which can appropriately reduce some costs compared with using an aspherical glass lens.

[0010] In some possible embodiments, the optical lens further includes a fixed-position aperture stop, and the aperture stop is located between the second lens group and the third lens group. The diameter of the aperture stop can be adjusted to flexibly adjust the aperture size of the optical lens.

[0011] In some possible embodiments, the minimum distance between the aperture stop and the second lens group is greater than or equal to 0.5 mm, and the distance between the aperture stop and the third lens group is greater than or equal to 0.5 mm. That is to say, the aperture stop should maintain a certain distance from both the second lens group and the third lens group, so that there is a certain position margin during the movement of the second lens group, which is convenient for controlling the movement stroke and can avoid collision with the aperture stop.

[0012] In some possible embodiments, the optical lens satisfies the following relational expressions: -0.5 < f2 / f1 < 0, 0 < f3 / f1 < 1, 0.5 < f4 / f1 < 1. Wherein, f1 represents the focal length of the first lens group, f2 represents the focal length of the second lens group, f3 represents the focal length of the third lens group, and f4 represents the focal length of the fourth lens group. Through this design, the optical lens has good zoom ability and imaging quality.

[0013] In some possible embodiments, the first lens group includes two aspherical plastic lenses, the second lens group includes two aspherical plastic lenses, and the third lens group includes two aspherical plastic lenses. Here, a specific embodiment of paired aspherical plastic lenses is given, which has the characteristics of miniaturization, low cost, high imaging performance, and relatively high thermal stability.

[0014] In some possible embodiments, the first lens group includes lens 1-1, lens 1-2, lens 1-3, lens 1-4, and lens 1-5, the second lens group includes lens 2-1, lens 2-2, and lens 2-3, the third lens group includes lens 3-1, lens 3-2, and lens 3-3, and the fourth lens group includes lens 4-1, lens 4-2, and lens 4-3. Lens 1-1, lens 1-2, lens 1-4, lens 2-1, lens 3-2, lens 4-1, lens 4-2, and lens 4-3 are glass spherical lenses. Lens 1-3, lens 1-5, lens 2-2, lens 2-3, lens 3-1, and lens 3-3 are aspherical plastic lenses. Here, a specific design method of each lens group in the optical lens is given, which has good practical effects.

[0015] In some possible embodiments, the second lens group includes two aspherical plastic lenses, the third lens group includes two aspherical plastic lenses, and the fourth lens group includes two aspherical plastic lenses. Here, another specific embodiment of paired aspherical plastic lenses is given, which has the characteristics of miniaturization, low cost, high imaging performance, and relatively high thermal stability.

[0016] In some possible embodiments, the first lens group includes lens 1-1, lens 1-2, lens 1-3, lens 1-4, and lens 1-5, the second lens group includes lens 2-1, lens 2-2, and lens 2-3, the third lens group includes lens 3-1, lens 3-2, and lens 3-3, and the fourth lens group includes lens 4-1, lens 4-2, and lens 4-3. Lens 1-1, lens 1-2, lens 1-3, lens 1-4, lens 1-5, lens 2-1, lens 3-2, and lens 4-2 are glass spherical lenses. Lens 2-2, lens 2-3, lens 3-1, lens 3-3, lens 4-1, and lens 4-3 are aspherical plastic lenses. Here, another specific design method of each lens group in the optical lens is given, which enriches the implementation methods of this solution.

[0017] In some possible embodiments, the second lens group is used for zooming by moving along the optical axis, and the fourth lens group is used for compensating for the offset of the image plane position by moving along the optical axis. That is to say, the fourth lens group is used to move in cooperation with the movement of the second lens group to keep the position of the image plane unchanged, that is, to keep the overall optical length of the optical lens unchanged.

[0018] In some possible embodiments, as the positions of the second lens group and the fourth lens group move, the focal length change range of the optical lens is from 5.5 mm to 129 mm, having good zooming ability.

[0019] In some possible embodiments, the aperture of the first lens group in the optical lens is the largest, which is beneficial to realizing a large field of view.

[0020] In some possible embodiments, the optical lens further includes a protective glass, which is located on the image side of the fourth lens group, providing good airtightness for the optical lens.

[0021] In some possible embodiments, the aperture number change range of the optical lens is from 1.6 to 4.8, having a large adjustable range of the aperture.

[0022] In a second aspect, an embodiment of the present application provides a camera. The camera includes a photosensitive element and an optical lens as introduced in any one of the embodiments of the first aspect. The photosensitive element is located on the image side of the optical lens. The optical lens is used to project a light beam from a photographed object onto the photosensitive element, and the photosensitive element is used to convert the light beam into image data.

[0023] In a third aspect, an embodiment of the present application provides an electronic device. The electronic device includes an image processor and a camera as introduced in the second aspect. The image processor is connected to the camera, and the image processor is used to obtain image data from the camera and process the image data.

[0024] In the embodiments of the present application, the optical lens includes 4 lens groups. With the premise of ensuring the realization of the functions of the optical lens, the number of lens groups adopted is small, which is convenient for realizing miniaturization. At least one lens group in the optical lens includes an even number of aspherical plastic lenses. On the one hand, using some aspherical plastic lenses can reduce costs while ensuring good imaging quality; on the other hand, designing an even number of aspherical plastic lenses in the same lens group helps to improve the thermal stability of the optical lens, that is, reduces the influence of the ambient temperature on the imaging quality, and can ensure good imaging in an environment of -30°C to 70°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a dome camera;

[0026] Figure 2 It is the first structural schematic diagram of the optical lens in the embodiment of the present application;

[0027] Figure 3 It is the second structural schematic diagram of the optical lens in the embodiment of the present application;

[0028] Figure 4 It is a schematic diagram of a zooming method of the optical lens in the embodiment of the present application;

[0029] Figure 5 It is the structural schematic diagram of a camera in the embodiment of the present application;

[0030] Figure 6 It is the structural schematic diagram of an electronic device in the embodiment of the present application. Specific Embodiments

[0031] The embodiment of the present application provides an optical lens, a camera, and an electronic device, which have the characteristics of miniaturization, low cost, high imaging performance, and high thermal stability.

[0032] It should be noted that the terms "first", "second", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order different from that shown or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0033] For ease of understanding, the technical terms involved in the embodiment of the present application are first explained below.

[0034] Focal power, which is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, characterizes the ability of the optical system to deflect light rays. A lens or lens group with positive focal power has a positive focal length and has the effect of converging light rays. A lens or lens group with negative focal power has a negative focal length and has the effect of diverging light rays.

[0035] Focal length, also known as the focal distance, is a measure of how light converges or diverges in an optical system. It refers to the perpendicular distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through the lens or lens group. For a thin lens, the focal length is the distance from the center of the lens to the imaging plane; for a thick lens or a lens group, the focal length is equal to the effective focal length (EFL), which is the distance between the rear principal plane of the lens or lens group and the imaging plane.

[0036] Object side: Taking the lens as the boundary, the side where the scene to be imaged is located is the object side.

[0037] Image side: Taking the lens as the boundary, the side where the image of the scene to be imaged is located is the image side.

[0038] Object side surface: Taking the lens as the boundary, the side where the object to be photographed is located is the object side, and the surface of the lens close to the object side is called the object side surface.

[0039] Image side surface: Taking the lens as the boundary, the side where the image of the object to be photographed is located is the image side, and the surface of the lens close to the image side is called the image side surface.

[0040] Imaging plane: It is located on the image side of all the lenses in the optical lens, and is the plane where the light forms an image after passing through each lens in the optical lens in sequence.

[0041] Aperture: It is a device used to control the amount of light passing through the lens and entering the photosensitive surface inside the camera body. It is usually inside the lens.

[0042] Aperture number, also known as the F-number (Fno), is the relative value obtained by dividing the focal length of the lens by the diameter of the entrance pupil of the lens (the reciprocal of the relative aperture). The smaller the aperture value, the more light enters in the same unit of time. The larger the aperture value, the smaller the depth of field, and the background content of the photo will be blurred, similar to the effect of a telephoto lens.

[0043] Field of view (FOV): In an optical instrument, with the vertex of the optical instrument's lens as the vertex and the two edges of the maximum range through which the image of the measured target can pass through the lens forming an included angle, it 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.

[0044] Aberration: The paraxial region of an optical system has the properties of an ideal optical system. The paraxial rays emitted from a point on the object intersect at a point on the image plane (i.e., the paraxial image point). However, the actual rays passing through different apertures of the lens are difficult to intersect perfectly at a point, but deviate from the position of the paraxial image point to a certain extent. These differences are collectively called aberrations.

[0045] The optical axis is a ray of light that perpendicularly 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. This point where all the rays converge is the focal point. When the light ray propagates along the optical axis, its propagation direction does not change.

[0046] The optical lens provided by the embodiment of the present application can be applied to a PTZ camera for monitoring and recognition of a large - scale scene.

[0047] Figure 1 It is a schematic structural diagram of a PTZ camera. A PTZ camera can also be called a spherical camera and is used for collecting videos. The PTZ camera can include a pan - tilt head driven by a stepper motor and a camera installed on the pan - tilt head. The pan - tilt head is a supporting device for fixing the camera, and the camera includes an optical lens. The pan - tilt head can rotate in the horizontal or vertical direction, and the camera installed on the pan - tilt head can rotate with the pan - tilt head in the horizontal or vertical direction. The focal length of the optical lens of the camera can be adjusted. By controlling the rotation of the pan - tilt head and adjusting the focal length of the optical lens, the monitoring range of the PTZ camera can be adjusted. The monitoring range of the PTZ camera can be regarded as the visible range of the PTZ camera or the shooting range when the PTZ camera collects videos.

[0048] It should be understood that the optical lens provided by the embodiment of the present application has better performance and lower cost. In this way, by adopting the optical lens provided by the embodiment of the present application, the cost of the PTZ camera can be effectively reduced. For example, while having the performance of a 6 - inch PTZ camera, the overall structural length can be shortened to the size of a 5 - inch PTZ camera. That is to say, applying the optical lens provided by the embodiment of the present application to a 5 - inch PTZ camera can achieve the performance of the original 6 - inch PTZ camera. In this case, while maintaining the high performance of the lens, the cost of the lens packaging structure can be saved, and the cost of the optical lens can be reduced by about 30%. Coupled with the mechanical structure cost reduction of about 40%. The following will introduce the optical lens provided by the embodiment of the present application in detail.

[0049] Figure 2 It is the first schematic structural diagram of the optical lens in the embodiment of the present application. As Figure 2 shown, the lens groups 1, 2, 3, and 4 of the optical lens are arranged along the optical axis from the object side to the image side. Among them, the positions of lens group 1 and lens group 3 are fixed. Lens group 1 is mainly used to correct the large - field aberration, and lens group 3 mainly plays the role of focusing light and correcting spherical aberration. Lens groups 2 and 4 can move along the direction of the optical axis. Lens group 2 zooms by moving along the optical axis, and lens group 4 compensates for the offset of the image plane position by moving along the optical axis to correct various aberrations. That is to say, lens group 4 is used to move in cooperation with the movement of lens group 2 to keep the position of the image plane unchanged, that is, to keep the optical total length of the optical lens unchanged. For example, the optical total length of the optical lens is 93.3 mm.

[0050] Specifically, the lens group 1, the lens group 3 and the lens group 4 have positive optical powers, and the lens group 2 has a negative optical power, which is beneficial to achieving an ideal zoom ratio. The focal length of the lens group 1 is denoted as f1, the focal length of the lens group 2 is denoted as f2, the focal length of the lens group 3 is denoted as f3, and the focal length of the lens group 4 is denoted as f4. As an example, the optical lens satisfies the following relational expressions: -0.5 < f2 / f1 < 0, 0 < f3 / f1 < 1, 0.5 < f4 / f1 < 1. Through this design, the optical lens has good zooming ability and imaging quality. In some specific scenarios, the resolution of the central field of view 0F of the optical lens is higher than 1250 TVline, and the resolution of the peripheral 0.7F field of view is higher than 1000 TVline.

[0051] In some possible implementation manners, the optical lens further includes an aperture stop and a protective glass. Among them, the position of the aperture stop is fixed and is located between the lens group 2 and the lens group 3, and the protective glass is located on the image side of the lens group 4. The aperture stop can play a role in restricting the light entering the lens, and moreover, the diameter of the aperture stop is adjustable. By adjusting the aperture stop, the aperture size of the optical lens can be changed. For example, the aperture number range of the optical lens provided in the embodiment of the present application is from 1.6 to 4.8. In practical applications, the aperture stop needs to maintain a certain distance from both the lens group 2 and the lens group 3, so that there is a certain position margin during the movement of the lens group 2, which is convenient for controlling the movement stroke and can avoid collision with the aperture stop. For example, the minimum distance between the aperture stop and the lens group 2 is greater than or equal to 0.5 mm, that is, the distance when the lens group 2 moves to the closest position to the aperture stop is 0.5 mm, and the distance between the aperture stop and the lens group 3 is greater than or equal to 0.5 mm.

[0052] It should be noted that at least one of the above 4 lens groups includes an even number of aspherical plastic lenses. Such a design is mainly considered in the following aspects. First, on the premise of the same number of lenses, using some plastic lenses has a lower cost compared with glass lenses. Second, using aspherical lenses has smaller aberrations and better imaging quality compared with spherical lenses. Third, since the thermal expansion coefficient of plastic materials is larger than that of glass materials, it is more affected by high and low temperature environments, and the thermal expansion and contraction of the material itself will have a greater impact on the lens surface shape and thickness, resulting in worse thermal stability of the optical lens in extreme temperature environments. Therefore, in the embodiment of the present application, the aspherical plastic lenses are placed in pairs in the same lens group, which helps to improve the thermal stability of the optical lens, that is, reduces the influence of the environmental temperature on the imaging quality, and can ensure good imaging in the environment of -30°C to 70°C.

[0053] Optionally, taking two aspherical plastic lenses in a lens group as an example, the signs of the optical powers of the two aspherical plastic lenses are opposite. Further, the absolute values of the optical powers of the two aspherical plastic lenses are similar or equal. In this way, as the temperature changes, the total optical power of the lens group remains as constant as possible, thereby reducing the influence of the ambient temperature on the performance stability of the lens and improving the thermal stability of the entire lens. For example, the two aspherical plastic lenses are respectively denoted as the first aspherical plastic lens and the second aspherical plastic lens. represents the optical power of the first aspherical plastic lens. represents the optical power of the second aspherical plastic lens, then it satisfies In a possible scenario, that is In another possible scenario, Among the two aspherical plastic lenses, the one with the larger absolute value of the optical power is denoted as the first aspherical plastic lens, and the one with the smaller absolute value of the optical power is denoted as the second aspherical plastic lens, then It should be understood that the specific value of the preset value is not limited in this application, and in practical applications, the preset value can be flexibly set according to actual needs. For example, the preset value is 5, that is it is considered that the absolute values of the optical powers of the two aspherical plastic lenses are similar or equal.

[0054] It should be understood that the number of lenses in each lens group is not limited in the embodiments of this application, nor is it limited to which specific lens groups include an even number of aspherical plastic lenses. Generally, lens group 1 is the lens group with the largest aperture in the optical lens, which is beneficial to achieving a large field of view. Setting paired aspherical plastic lenses in lens group 1 is beneficial to maximizing cost reduction. In addition to the several embodiments provided in this application, other embodiments that can be flexibly transformed by those skilled in the art based on this are also within the protection scope of this application.

[0055] It should also be understood that except for the paired aspherical plastic lenses mentioned above, the materials and types of other lenses in the optical lens are not limited here. As an example, other lenses can all be glass lenses, which is beneficial to improving the zoom ability, imaging quality, and thermal stability of the optical lens. For example, a glass material with a high refractive index can be used to improve the zoom ability. Another example is to use a glass material with low dispersion to reduce the influence of chromatic aberration on the imaging quality. Further, the glass lenses used can specifically be glass spherical mirrors, which can appropriately reduce some costs compared to using glass aspherical mirrors.

[0056] In addition, when the optical lens provided by the embodiment of the present application is used in a low-light environment, it can image light in the near-infrared band, so as to cooperate with the visible light band to improve the resolution ability of the lens. That is to say, the optical lens provided by the embodiment of the present application can achieve confocal imaging in the visible light and infrared bands, and still can clearly capture the contour information and color information of an object in a dark low-light environment.

[0057] Next, a specific structural design of the optical lens will be introduced by taking Figure 2 as an example. Among them, Figure 2 the reference numerals of each lens in

[0058] Table 1

[0059] Label Name Label Name 1-1 Lens 1 of Lens Group 1 2-3 Lens 3 of Lens Group 2 1-2 Lens 2 of Lens Group 1 3-1 Lens 1 of Lens Group 3 1-3 Lens 3 of Lens Group 1 3-2 Lens 2 of Lens Group 3 1-4 Lens 4 of Lens Group 1 3-3 Lens 3 of Lens Group 3 1-5 Lens 5 of Lens Group 1 4-1 Lens 1 of Lens Group 4 2-1 Lens 1 of Lens Group 2 4-2 Lens 2 of Lens Group 4 2-2 Lens 2 of Lens Group 2 4-3 Lens 3 of Lens Group 4

[0060] Among them, the lens group 1 includes two aspheric plastic lenses, the lens group 2 includes two aspheric plastic lenses, and the lens group 3 includes two aspheric plastic lenses. Specifically, the lenses 1-1, 1-2, 1-4, 2-1, 3-2, 4-1, 4-2, and 4-3 are glass spherical lenses. The lenses 1-3, 1-5, 2-2, 2-3, 3-1, and 3-3 are aspheric plastic lenses. Figure 2 The detailed parameters of each lens in the shown embodiment are shown in Table 2 below.

[0061] Table 2

[0062] Surface Number Surface Type Radius R Thickness Material Effective Semi-Aperture Object Surface Standard Sphere Infinity Infinity AIR Infinity S1 Standard Sphere 65.8 1.9 H-ZLAF78B 12.5 S2 Standard Sphere 26.1 6.9 H-FK95N 11.1 S3 Standard Sphere -142.1 0.1 AIR 9.6 S4 Even Asphere 58.1 1.5 K26R 8.9 S5 Even Asphere 62.6 0.1 AIR 8.3 S6 Standard Sphere 36.6 3.5 H-LAK59A 8.0 S7 Standard Sphere 127.4 0.1 AIR 6.8 S8 Even Asphere 51.2 3.1 K26R 6.5 S9 Even Asphere 228.3 0.5 AIR 5.0 S10 Standard Sphere -35.7 0.9 H-ZLAF4LA 4.8 S11 Standard Sphere 6.0 1.9 AIR 4.0 S12 Even Asphere 23.0 1.0 EP3500 4.0 S13 Even Asphere 10.2 0.4 AIR 4.4 S14 Even Asphere 636.0 2.2 EP8000 4.6 S15 Even Asphere -11.3 33.1 AIR 4.6 Aperture Stop Standard Sphere Infinity 0.5 AIR 6.8 S17 Even Asphere 11.2 2.5 EP8000 7.2 S18 Even Asphere 15.2 0.1 AIR 6.7 S19 Standard Sphere 10.5 4.6 H-FK55 6.7 S20 Standard Sphere -20.9 0.1 AIR 6.4 S21 Even Asphere 365.4 0.7 EP8000 5.8 S22 Even Asphere 9.9 8.4 AIR 5.0 S23 Standard Sphere 27.3 2.8 EP9000 4.6 S24 Standard Sphere -9.9 0.1 AIR 4.5 S25 Standard Sphere -9.5 0.7 H-ZF62 4.5 S26 Standard Sphere 47.6 0.1 AIR 4.6 S27 Standard Sphere 20.8 2.8 H-K8 4.7 S28 Standard Sphere -13.4 9.7 AIR 4.8 S29 Standard Sphere Infinity 1 BSC7 3.5 S30 Standard Sphere Infinity 1 AIR 3.2 Image Surface Standard Sphere Infinity - - 3.1

[0063] In Figure 2 the shown embodiment, the optical lens includes 6 aspheric plastic lenses, and the aspheric surface shape of the aspheric plastic lens satisfies the following conditions:

[0064]

[0065] Among them, c is the radius of curvature, y is the radial coordinate (the unit is the same as the lens length unit), k is the conic quadratic curve coefficient (conic coefficient). When the conic coefficient is less than -1, the surface type is a hyperbola. When the conic coefficient is equal to -1, it is a parabola. When the conic coefficient is between -1 and 0, it is an ellipse. When the conic coefficient is equal to 0, it is a circle. When the conic coefficient is greater than 0, it is an oblate circle. A1, A2, A3, A4, A5, A6, A7, and A8 are high-order aspheric coefficients. The aspheric surface type of the lens can be set through the above parameters. Figure 2 The aspheric coefficients of each aspheric plastic lens in the shown embodiment are shown in Table 3 below.

[0066] Table 3

[0067] Conic A1 A2 A3 A4 A5 A6 A7 A8 S4 -6.8 0 -4.9E-06 -1.4E-08 -1.1E-10 -4.8E-13 -4.1E-16 6.4E-18 0 S5 -2.6 0 -1.8E-06 -1.7E-08 -6.0E-11 -9.0E-13 -1.3E-15 1.2E-17 0 S8 1.1 0 1.5E-06 -2.2E-09 -1.7E-11 4.7E-13 2.9E-15 -2.2E-17 0 S9 -10.0 0 -8.5E-06 1.5E-08 1.6E-10 7.2E-13 5.1E-16 -2.3E-17 0 S12 -10.0 0 -2.5E-03 4.5E-06 -1.9E-06 -6.0E-08 5.3E-09 3.2E-10 -3.8E-11 S13 -10.0 0 -2.1E-03 -2.1E-05 -1.4E-07 -9.3E-08 5.0E-09 -8.0E-11 -3.0E-12 S14 9.7 0 -2.2E-04 3.0E-05 -1.1E-06 2.0E-08 -.32E-10 5.5E-11 -1.8E-12 S15 2.4 0 -1.9E-05 2.5E-05 -3.0E-08 2.6E-08 4.4E-10 -6.3E-11 4.3E-13 S17 0.2 0 2.5E-04 -2.5E-06 -2.2E-08 7.9E-10 -9.9E-12 6.6E-14 9.1E-16 S18 2.2 0 4.3E-04 -3.5E-06 -1.6E-07 2.5E--09 -7.8E-12 2.4E-13 2.3E-15 S21 10.0 0 -2.5E-04 -1.3E-05 2.4E-07 -3.6E-09 2E-10 -6.3E-14 -5.5E-14 S22 1.7 0 -4.5E-04 -8.5E-06 -4.1E-07 4.0E-08 -1.1E-09 1.8E-11 -1.9E-13

[0068] Figure 3 This is the second structural schematic diagram of the optical lens in the embodiment of the present application. Different from the above Figure 2 shown optical lens, Figure 3 Another specific structural design of the optical lens is given. Among them, Figure 3 the reference numerals of each lens can still refer to Table 1. The lens group 2 includes two aspherical plastic lenses, the lens group 3 includes two aspherical plastic lenses, and the lens group 4 includes two aspherical plastic lenses. Specifically, the lenses 1-1, 1-2, 1-3, 1-4, 1-5, 2-1, 3-2, and 4-2 are glass spherical lenses. The lenses 2-2, 2-3, 3-1, 3-3, 4-1, and 4-3 are aspherical plastic lenses. Figure 3 The detailed parameters of each lens in the shown embodiment are as shown in Table 4 below.

[0069] Table 4

[0070]

[0071]

[0072] Figure 3 The aspherical coefficients of each aspherical plastic lens in the shown embodiment are as shown in Table 5 below.

[0073] Table 5

[0074]

[0075]

[0076] Next, the zoom scenario of the optical lens in the embodiment of the present application will be introduced. For example, as the positions of the lens group 2 and the lens group 4 move, the focal length change range of the optical lens can be from 5.5 mm to 129 mm. That is, the focal length of the optical lens provided in the embodiment of the present application reaches 5.5 mm at the wide-angle end and 129 mm at the telephoto end.

[0077] Figure 4 This is a schematic diagram of a zooming method of the optical lens in the embodiment of the present application. As Figure 4As shown in the figure, as the positions of lens group 2 and lens group 4 move, the focal length of the optical lens can change. Based on the change in the focal length of the optical lens, in this embodiment, the optical lens can be divided into three states: short focal length, medium focal length, and long focal length. Taking the initial state of the optical lens being short focal length as an example, lens group 2 moves towards lens group 3, and lens group 4 moves towards lens group 3, so that the optical lens switches to the medium focal length state. Furthermore, lens group 2 continues to move towards lens group 3, and lens group 4 moves away from lens group 3, so that the optical lens switches to the long focal length state.

[0078] In the above Figure 2 In the scenario shown above, as the positions of lens group 2 and lens group 4 move, the focal length change parameters of the optical lens can be as shown in Table 6 below. Among them, the spacing 1 in Table 6 represents the distance between lens group 1 and lens group 2, the spacing 2 represents the distance between lens group 2 and lens group 3, the spacing 3 represents the distance between lens group 3 and lens group 4, and the spacing 4 represents the distance between lens group 4 and the protective glass.

[0079] Table 6

[0080] Focal Length / mm 5.5 12.1 26.6 58.6 129.0 Spacing 1 / mm 0.5 13.8 22.7 29.5 33.2 Spacing 2 / mm 33.2 20.0 11.0 4.2 0.5 Spacing 3 / mm 8.5 4.3 0.9 2.0 17.8 Spacing 4 / mm 9.8 14.0 17.3 16.2 0.5

[0081] In the above Figure 3 In the scenario shown above, as the positions of lens group 2 and lens group 4 move, the focal length change parameters of the optical lens can be as shown in Table 7 below. Among them, the spacing 1 in Table 7 represents the distance between lens group 1 and lens group 2, the spacing 2 represents the distance between lens group 2 and lens group 3, the spacing 3 represents the distance between lens group 3 and lens group 4, and the spacing 4 represents the distance between lens group 4 and the protective glass.

[0082] Table 7

[0083] Focal Length / mm 5.5 12.1 26.6 58.6 129.0 Spacing 1 / mm 0.5 13.9 23.2 30.3 34.1 Spacing 2 / mm 34.4 20.5 11.2 4.2 0.5 Spacing 3 / mm 5.3 2.8 0.7 1.4 16.1 Spacing 4 / mm 10.5 13.8 16.3 15.0 0.5

[0084] As can be seen from the above introduction, in the embodiment of the present application, the optical lens includes 4 lens groups. With a relatively small number of lens groups while ensuring the realization of the functions of the optical lens, it is convenient to achieve miniaturization. At least one lens group in the optical lens includes an even number of aspherical plastic lenses. On the one hand, using some aspherical plastic lenses can reduce costs while ensuring good imaging quality; on the other hand, designing an even number of aspherical plastic lenses in the same lens group helps to improve the thermal stability of the optical lens, that is, reduces the influence of the ambient temperature on the imaging quality, and can ensure good imaging in an environment of -30°C to 70°C.

[0085] The embodiments of the present application also provide a camera and an electronic device, which will be introduced separately below. It should be understood that the electronic device may be a device with a shooting function such as a mobile phone, a tablet computer, a wearable device, a spherical camera, etc., and specific details are not limited here.

[0086] Figure 5 It is a schematic structural diagram of a camera in an embodiment of the present application. As Figure 5 shown, the camera includes an optical lens 101 and a photosensitive element 102. Among them, the photosensitive element 102 is located on the image side of the optical lens 101. The optical lens 101 is used to project the light beam from the object to be photographed onto the photosensitive element 102, and the photosensitive element 102 is used to convert the light beam into image data. In some possible implementation manners, the camera further includes a prism or a mirror for changing the direction of the light path, so that the light after passing through the prism or the mirror can propagate along the extension direction of the optical axis of the optical lens 101. For example, in this way, the light path deflection is formed to realize a periscope light path.

[0087] It should be understood that the optical lens 101 may be the optical lens introduced in any of the above embodiments, which will not be elaborated here. The photosensitive element 102 is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When irradiated by light, it will generate charges. The photosensitive element 102 may be a charge coupled device (CCD) or a complementary metal-oxide semiconductor device (CMOS). The charge coupled device is made of a high-sensitivity semiconductor material and can convert light into charges. The charge coupled device consists of many photosensitive units, usually in units of millions of pixels. When the surface of the charge coupled device is irradiated by light, each photosensitive unit will reflect the charge on the component, and the signals generated by all the photosensitive units are added together to form a complete picture. The complementary metal-oxide semiconductor device mainly uses semiconductors made of silicon and germanium elements, so that N (negatively charged) and P (positively charged) type semiconductors coexist on the complementary metal-oxide semiconductor device. The current generated by these two complementary effects can be recorded and interpreted into an image by the image sensor.

[0088] Figure 6 It is a schematic structural diagram of an electronic device in an embodiment of the present application. As Figure 6 shown, the electronic device includes a camera 201 and an image processor 202. Among them, the camera 201 may be the camera introduced Figure 5 above. The image processor 202 is connected to the camera 201, and the image processor 202 is used to obtain image data from the camera 201 and process the image data.

[0089] It should be noted that the communication connection between the camera 201 and the image processor 202 can include data transmission through electrical connection means such as wiring, or data transmission can also be achieved through coupling or other means. It should be understood that the camera 201 and the image processor 202 can also be communicatively connected through other means capable of data transmission. The function of the image processor 202 is to optimize the digital image signal through a series of complex mathematical algorithm operations, and finally transmit the processed signal to the display for image display. The image processor 202 can be an image processing chip or a digital signal processing chip (DSP), etc., which can process image signals and digital signals. Its role is to quickly transfer the data obtained by the photosensitive chip of the camera 201 to the central processor and refresh the photosensitive chip. Therefore, the quality and stability of the DSP chip directly affect the picture quality (such as color saturation, clarity, etc.).

[0090] In some possible implementation manners, the electronic device may further include an analog-to-digital converter. The analog-to-digital converter is connected between the camera 201 and the image processor 202. The analog-to-digital converter is used to convert the signal generated by the camera 201 into a digital image signal and transmit it to the image processor 202, and then the image processor 202 processes the digital image signal, and finally the image or video is displayed through the display.

[0091] In some possible implementation manners, the electronic device may further include a memory. The memory is communicatively connected to the image processor 202. After the image processor 202 processes the image digital signal, the image is transmitted to the memory, so that the image can be retrieved from the memory at any time when it is necessary to view the image later and displayed on the display. In some embodiments, the image processor 202 will also compress the processed image digital signal and then store it in the memory to save memory space.

[0092] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

Claims

1. An optical lens, characterized in that, Comprising: A first lens group, a second lens group, a third lens group, and a fourth lens group arranged along the optical axis from the object side to the image side, wherein the positions of the first lens group and the third lens group are fixed, and the second lens group and the fourth lens group are movable along the optical axis; The first lens group, the third lens group, and the fourth lens group have positive optical powers, the second lens group has a negative optical power, and at least one lens group in the optical lens comprises an even number of aspherical plastic lenses.

2. The optical lens according to claim 1, wherein Every two aspherical plastic lenses in the same lens group form a pair. The signs of the optical powers of the two aspherical plastic lenses in the same pair are opposite, and the ratio of the absolute values of the optical powers of the two aspherical plastic lenses in the same pair satisfies where represents the optical power of the first aspherical plastic lens among the two aspherical plastic lenses in the same pair, represents the optical power of the second aspherical plastic lens among the two aspherical plastic lenses in the same pair.

3. The optical lens according to claim 1 or 2, characterized in that, Each lens group in the optical lens comprises at least one glass lens.

4. The optical lens according to claim 3, wherein Each glass lens in the optical lens is a spherical glass lens.

5. The optical lens according to any one of claims 1 to 4, characterized in that, The optical lens further comprises a fixed-position aperture stop, which is located between the second lens group and the third lens group, and the diameter of the aperture stop is adjustable.

6. The optical lens according to claim 5, wherein The minimum distance between the aperture stop and the second lens group is greater than or equal to 0.5 mm, and the distance between the aperture stop and the third lens group is greater than or equal to 0.5 mm.

7. The optical lens according to any one of claims 1 to 6, characterized in that, The optical lens satisfies the following relational expressions: -0.5 < f2 / f1 < 0, 0 < f3 / f1 < 1, 0.5 < f4 / f1 < 1; wherein, f1 represents the focal length of the first lens group, f2 represents the focal length of the second lens group, f3 represents the focal length of the third lens group, and f4 represents the focal length of the fourth lens group.

8. The optical lens according to any one of claims 1 to 7, characterized in that, The first lens group comprises two aspherical plastic lenses, the second lens group comprises two aspherical plastic lenses, and the third lens group comprises two aspherical plastic lenses.

9. The optical lens according to claim 8, characterized in that, The first lens group comprises lens 1-1, lens 1-2, lens 1-3, lens 1-4, and lens 1-5, the second lens group comprises lens 2-1, lens 2-2, and lens 2-3, the third lens group comprises lens 3-1, lens 3-2, and lens 3-3, and the fourth lens group comprises lens 4-1, lens 4-2, and lens 4-3; Lens 1-1, lens 1-2, lens 1-4, lens 2-1, lens 3-2, lens 4-1, lens 4-2, and lens 4-3 are spherical glass lenses, and lens 1-3, lens 1-5, lens 2-2, lens 2-3, lens 3-1, and lens 3-3 are aspherical plastic lenses.

10. The optical lens according to any one of claims 1 to 7, characterized in that, The second lens group comprises two aspherical plastic lenses, the third lens group comprises two aspherical plastic lenses, and the fourth lens group comprises two aspherical plastic lenses.

11. The optical lens according to claim 10, wherein, The first lens group comprises lens 1-1, lens 1-2, lens 1-3, lens 1-4, and lens 1-5, the second lens group comprises lens 2-1, lens 2-2, and lens 2-3, the third lens group comprises lens 3-1, lens 3-2, and lens 3-3, and the fourth lens group comprises lens 4-1, lens 4-2, and lens 4-3; Lens 1-1, lens 1-2, lens 1-3, lens 1-4, lens 1-5, lens 2-1, lens 3-2, and lens 4-2 are spherical glass lenses, and lens 2-2, lens 2-3, lens 3-1, lens 3-3, lens 4-1, and lens 4-3 are aspherical plastic lenses.

12. The optical lens according to any one of claims 1 to 11, characterized in that, The second lens group is used for zooming by moving along the optical axis, and the fourth lens group is used for compensating for the shift of the image plane position by moving along the optical axis.

13. The optical lens according to any one of claims 1 to 12, characterized in that, As the positions of the second lens group and the fourth lens group move, the focal length variation range of the optical lens is from 5.5 mm to 129 mm.

14. The optical lens according to any one of claims 1 to 13, characterized in that, In the optical lens, the first lens group has the largest aperture.

15. The optical lens according to any one of claims 1 to 14, characterized in that, The optical lens further includes a protective glass, and the protective glass is located on the image side of the fourth lens group.

16. The optical lens according to any one of claims 1 to 15, characterized in that, The aperture number variation range of the optical lens is from 1.6 to 4.

8.

17. A camera, characterized in that, Comprising: An image sensor and the optical lens according to any one of claims 1 to 16, the image sensor being located on the image side of the optical lens, the optical lens being configured to project a light beam from a subject onto the image sensor, and the image sensor being configured to convert the light beam into image data.

18. An electronic device, characterized in that, Comprising: An image processor and the camera according to claim 17, the image processor being connected to the camera, and the image processor being configured to acquire image data from the camera and process the image data.

Images