Lens and camera device

Abstract

The present invention discloses a lens and a camera device, which are composed of a first negative power lens, a second negative power lens, a first positive power lens, a second positive power lens, a lens group, a fourth negative power lens, a fourth positive power lens and a fifth positive power lens arranged in sequence from the object side to the image side; the image side of the fifth positive power lens includes a filter and an image plane in sequence; the lens group satisfies the following conditions: #imgabs0# wherein f G1 is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens; the lens group is composed of a third negative power lens and a third positive power lens arranged in sequence from the object side to the image side. A full-frame optical lens with high resolution, large target surface, low distortion, miniaturization and low cost is realized.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a lens and a camera device. Background Art

[0002] In recent years, the field of security monitoring has ushered in a rapid development. Optical lenses have been increasingly used in the field of security, especially in the fields of smart buildings and smart transportation. The pixel requirements of optical imaging lenses are getting higher and higher. And as the number of lanes on the road gradually upgrades from 2 lanes to 3 lanes, 4 lanes and even 5 lanes, the field of view that needs to be monitored is getting larger and larger, so the image surface of the sensor is also constantly upgraded to a large target surface. Now full-frame large-target surface cameras are gradually appearing on the market, but there are few lenses that can meet the full-frame image surface. In addition, the large target surface introduces greater distortion, so there is an urgent need for a lens that meets the full-frame target surface imaging requirements and requires low distortion on the market.

[0003] With the rapid development of the security field, fixed-focus lenses have more stable optical performance than zoom lenses, and their demand is also the highest. However, the following problems still exist in current optical imaging lenses: 1. The existing lenses have small imaging target sizes and low image resolution. 2. The lens distortion is large and cannot meet the needs of scenes with low distortion requirements. 3. A large number of lenses are used and the lens size is large, making it impossible to achieve a miniaturized design for the entire camera. 4. The lens resolution is not high and the imaging quality is average. 5. The performance stability is poor under high and low temperature conditions.

[0004] Therefore, the market is in urgent need of a full-frame optical lens with high resolution, large target area, low distortion, miniaturization and low cost. Summary of the invention

[0005] The embodiments of the present invention provide a lens and a camera device, which are used to provide a full-frame optical lens with high resolution, large target surface, low distortion, miniaturization and low cost.

[0006] An embodiment of the present invention provides a lens, wherein the lens is composed of a first negative power lens, a second negative power lens, a first positive power lens, a second positive power lens, a lens group, a fourth negative power lens, a fourth positive power lens and a fifth positive power lens, arranged in sequence from the object side to the image side; the image side of the fifth positive power lens includes a filter and an image plane in sequence;

[0007] The lens group meets the following conditions:

[0008]

[0009] Among them, f G1is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens;

[0010] The lens group consists of a third negative power lens and a third positive power lens which are arranged in sequence from the object side to the image side.

[0011] Furthermore, the first negative power lens is a meniscus lens, and a surface thereof facing the object side is a convex surface;

[0012] The second negative power lens is a meniscus lens, and the surface facing the object side is a convex surface;

[0013] The first positive power lens is a biconvex lens;

[0014] The second positive power lens is a meniscus lens, and a surface thereof facing the object side is a convex surface;

[0015] The third negative power lens is a meniscus lens, and the surface facing the object side is a convex surface;

[0016] The third positive power lens is a biconvex lens;

[0017] The fourth negative power lens is a biconcave lens;

[0018] The fourth positive power lens is a biconvex lens;

[0019] The fifth positive power lens is a meniscus lens, and a surface thereof facing the image side is a convex surface.

[0020] Furthermore, the three negative power lenses and the third positive power lens are a cemented lens group.

[0021] Furthermore, the central curvature radius R6 of the image side surface of the first positive power lens and the central curvature radius R7 of the object side surface of the second positive power lens satisfy:

[0022] Furthermore, a distance TTL from the object plane side of the first negative power lens to the image plane and a focal length f9 of the fifth positive power lens satisfy the following relationship: TTL / f9≤1.10.

[0023] Further, f1, the focal length of the first negative power lens, f4, the focal length of the second positive power lens, and f8, the focal length of the fourth positive power lens, satisfy the following conditions: f1≤-90.5; f4≤98.2; f8≤69.6.

[0024] Furthermore, the Abbe number Vd2 of the second negative power lens, the Abbe number Vd3 of the first positive power lens, and the Abbe number Vd5 of the third negative power lens satisfy: Vd2≤78.6; Vd3≤62.5; Vd5≤26.4.

[0025] Furthermore, the refractive index Nd2 of the second negative power lens, the refractive index Nd7 of the fourth negative power lens, and the refractive index Nd8 of the fourth positive power lens satisfy: Nd2≤1.65; Nd7≤2.05; Nd8≤1.98.

[0026] Furthermore, an aperture stop is arranged between the third positive power lens and the fourth negative power lens.

[0027] On the other hand, an embodiment of the present invention provides a camera device, which includes: using any of the above-mentioned lenses to perform imaging.

[0028] The embodiment of the present invention provides a lens and a camera device, wherein the lens is composed of a first negative power lens, a second negative power lens, a first positive power lens, a second positive power lens, a lens group, a fourth negative power lens, a fourth positive power lens and a fifth positive power lens arranged in sequence from the object side to the image side; the image side of the fifth positive power lens includes a filter and an image plane in sequence; the lens group meets the following conditions: Among them, f G1 is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens; the lens group is composed of a third negative power lens and a third positive power lens arranged in sequence from the object side to the image side. In the embodiment of the present invention, 9 lenses with specific focal powers are arranged in sequence from the object side to the image side in a specific order in the lens, and the third negative power lens and the third positive power lens constitute a lens group, and the lens group satisfies: A full-frame optical lens with high resolution, large target area, low distortion, miniaturization and low cost has been realized. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 1 A schematic diagram of a lens structure provided by an embodiment of the present invention;

[0031] Figure 2 The optical transfer function (MTF) curve of the lens provided in Example 1 of the present invention at room temperature in the visible light band;

[0032] Figure 3 Field curvature and distortion diagram of the lens provided in Example 1 of the present invention in the visible light band;

[0033] Figure 4 A transverse light fan diagram of the lens provided in Example 1 of the present invention in the visible light band;

[0034] Figure 5 A spot diagram of the lens provided in Example 1 of the present invention in the visible light band;

[0035] Figure 6 An optical transfer function (MTF) curve of the lens provided in Example 2 of the present invention at room temperature in the visible light band;

[0036] Figure 7 Field curvature and distortion diagram of the lens provided in Example 2 of the present invention in the visible light band;

[0037] Figure 8 A transverse light fan diagram of the lens provided in Example 2 of the present invention in the visible light band;

[0038] Fig. 9 This is a point diagram of the lens provided in Example 2 of the present invention in the visible light band. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Figure 1 A schematic diagram of a lens provided by an embodiment of the present invention, wherein the lens is composed of a first negative power lens L1, a second negative power lens L2, a first positive power lens L3, a second positive power lens L4, a lens group G1, a fourth negative power lens L7, a fourth positive power lens L8 and a fifth positive power lens L9 arranged in sequence from the object side to the image side; the image side of the fifth positive power lens L9 includes a filter M and an image plane N in sequence;

[0041] The lens group meets the following conditions:

[0042]

[0043] Among them, f G1 is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens;

[0044] The lens group G1 is composed of a third negative power lens L5 and a third positive power lens L6 which are arranged in sequence from the object side to the image side.

[0045] An aperture stop P is provided between the third positive power lens L6 and the fourth negative power lens L7.

[0046] The aperture size of the aperture diaphragm determines the aperture value of the system and the depth of field during shooting. Its aperture size can be fixed, or an adjustable aperture diaphragm can be placed as needed to achieve adjustable light aperture, that is, to achieve the purpose of variable system aperture value and changing depth of field.

[0047] The filter is an optical device used to select the required radiation band. By setting the filter, the filter in the lens provided by the embodiment of the present invention is simulated, so that the optical path difference of the filter in the lens is taken into account in the lens design, and the lens group in the lens satisfies: The lens performs better.

[0048] In the embodiment of the present invention, nine lenses with specific optical power are arranged in sequence from the object side to the image side in a specific order in the lens, and the third negative optical power lens and the third positive optical power lens constitute a lens group, and the lens group satisfies: A full-frame optical lens with high resolution, large target area, low distortion, miniaturization and low cost has been realized.

[0049] In order to further improve the imaging quality of the lens, in an embodiment of the present invention, the first negative optical power lens is a meniscus lens, and the surface facing the object side is a convex surface;

[0050] The second negative power lens is a meniscus lens, and the surface facing the object side is a convex surface;

[0051] The first positive power lens is a biconvex lens;

[0052] The second positive power lens is a meniscus lens, and a surface thereof facing the object side is a convex surface;

[0053] The third negative power lens is a meniscus lens, and the surface facing the object side is a convex surface;

[0054] The third positive power lens is a biconvex lens;

[0055] The fourth negative power lens is a biconcave lens;

[0056] The fourth positive power lens is a biconvex lens;

[0057] The fifth positive power lens is a meniscus lens, and a surface thereof facing the image side is a convex surface.

[0058] In order to make the lens more compact, in an embodiment of the present invention, the three negative power lenses and the third positive power lens are a cemented lens group.

[0059] In order to further improve the imaging quality of the lens and improve the processing performance of the lens, in an embodiment of the present invention, the central curvature radius R6 of the image side surface of the first positive focal power lens and the central curvature radius R7 of the object side surface of the second positive focal power lens satisfy the following relationship:

[0060] In order to further make the system compact, in an embodiment of the present invention, the distance TTL from the object plane side of the first negative power lens to the image plane and the focal length f9 of the fifth positive power lens satisfy: TTL / f9≤1.10.

[0061] In order to further improve the imaging quality of the lens, in an embodiment of the present invention, the focal length f1 of the first negative power lens, the focal length f4 of the second positive power lens and the focal length f8 of the fourth positive power lens satisfy: f1≤-90.5; f4≤98.2; f8≤69.6.

[0062] In the embodiment of the present invention, in order to achieve clear imaging in a wide temperature range of the lens, in the embodiment of the present invention, the Abbe number Vd2 of the second negative power lens, the Abbe number Vd3 of the first positive power lens, and the Abbe number Vd5 of the third negative power lens satisfy: Vd2≤78.6; Vd3≤62.5; Vd5≤26.4. In addition, satisfying: Vd2≤78.6; Vd3≤62.5; Vd5≤26.4 can also reduce the chromatic aberration of the image, thereby improving the imaging quality.

[0063] In order to improve the imaging quality of the lens and reduce the total length of the lens, in the embodiment of the present invention, the refractive index Nd2 of the second negative power lens, the refractive index Nd7 of the fourth negative power lens, and the refractive index Nd8 of the fourth positive power lens satisfy: Nd2≤1.65; Nd7≤2.05; Nd8≤1.98. In addition, satisfying: Nd2≤1.65; Nd7≤2.05; Nd8≤1.98 can also reduce spherical aberration and improve imaging quality.

[0064] On the other hand, an embodiment of the present invention provides a camera device, which includes: using the above-mentioned lens to perform imaging.

[0065] The optical performance achieved by the lens provided by the embodiment of the present invention is as follows:

[0066] The imaging target surface of the lens can support up to full-frame size, effectively realizing the miniaturization of the lens structure while ensuring the imaging quality. The imaging can support the use of sensors with a maximum target size of full frame, and the total mechanical length of the lens does not exceed 120mm; the full-field MTF value reaches more than 0.5 under the condition of 80lp / mm; the lens has a small number of lenses, good processability, and low cost control; the distortion is very small, within 2.5%, meeting the requirements of high-precision imaging; the optical performance is stable, meeting the requirements of high and low temperature working conditions of -30 to +70℃.

[0067] The following is an example of lens parameters provided by the embodiment of the present invention.

[0068] Embodiment 1:

[0069] In a specific implementation process, the curvature radius R, center thickness Tc, refractive index Nd, Abbe constant Vd and cone coefficient k of each lens of the lens meet the conditions listed in Table 1:

[0070]

[0071] Table 1

[0072] The lens provided in the embodiment of the present invention has the following optical technical indicators:

[0073] Total optical length TTL≤118.5mm;

[0074] Lens focal length f: 30.0mm;

[0075] Field of view of the lens: 14.5°;

[0076] Optical distortion of the lens: -2.5%;

[0077] Aperture of lens system F.NO: 4.0;

[0078] Lens image size: Φ46mm.

[0079] In Embodiment 1 of the present invention, lens L5 and lens L6 form a cemented lens group G1, and the focal length of the cemented lens group G1 is f G1 ; The focal length of the lens is f, and the field of view is FOV; the following relationship is satisfied: The central curvature radius R6 of the image side surface of the lens L3 of the optical lens and the central curvature radius R7 of the object side surface of the lens L4 satisfy: The focal length of lens L9 in the optical lens is f9, and the optical total length TTL of the optical lens satisfies: TTL / f9=0.83; the focal length of lens L1 of the optical lens is f1=-92.24, the focal length of lens L4 is f4=72.07, and the focal length of lens L8 is f8=32.92; the Abbe number Vd2 of lens L2 of the optical lens is 75.50, the Abbe number Vd3 of lens L3 is 55.90, and the Abbe number Vd5 of lens L5 is 20.88; the refractive index Nd2 of lens L2 of the optical lens is 1.55, the refractive index Nd7 of lens L7 is 1.85, and the refractive index Nd8 of lens L8 is 1.95.

[0080] Embodiment 2:

[0081] In a specific implementation process, the curvature radius R, center thickness Tc, refractive index Nd, Abbe constant Vd and cone coefficient k of each lens of the lens meet the conditions listed in Table 2:

[0082]

[0083] Table 2

[0084] The lens provided in this embodiment has the following optical technical indicators:

[0085] Total optical length TTL≤118.1mm;

[0086] Lens focal length f: 35.0mm;

[0087] Field of view of the lens: 15.2°;

[0088] Optical distortion of the lens: -2.4%;

[0089] Aperture of lens system F.NO: 4.0;

[0090] Lens image size: Φ46mm.

[0091] In Embodiment 2 of the present invention, lens L5 and lens L6 form a cemented lens group G1, and the focal length of the cemented lens group G1 is f G1 ; The focal length of the lens is f, and the field of view is FOV; the following relationship is satisfied: The central curvature radius R6 of the image side surface of the lens L3 of the optical lens and the central curvature radius R7 of the object side surface of the lens L4 satisfy: The focal length of lens L9 in the optical lens is f9, and the optical total length TTL of the optical lens satisfies: TTL / f9=0.32; the focal length of lens L1 of the optical lens is f1=-148.44, the focal length of lens L4 is f4=93.45, and the focal length of lens L8 is f8=64.83; the Abbe number Vd2 of lens L2 of the optical lens is 64.78, the Abbe number Vd3 of lens L3 is 58.42, and the Abbe number Vd5 of lens L5 is 23.79; the refractive index Nd2 of lens L2 of the optical lens is 1.50, the refractive index Nd7 of lens L7 is 2.00, and the refractive index Nd8 of lens L8 is 1.74.

[0092] In summary, Example 1 and Example 2 respectively satisfy the relationship shown in Table 3 below.

[0093]

[0094] Table 3

[0095] The lens provided in this embodiment is further described below by analyzing the optical system of the embodiment in detail.

[0096] The optical transfer function is a relatively accurate, intuitive and common way to evaluate the imaging quality of an optical system. The higher and smoother the curve is, the better the imaging quality of the system is and the aberrations are well corrected.

[0097] like Figure 2 , which is a graph of the optical transfer function (MTF) of the lens provided in Example 1 at room temperature in the visible light band;

[0098] like Figure 3 As shown, it is a diagram of field curvature and distortion of the lens provided in Example 1 in the visible light band;

[0099] like Figure 4 As shown, it is a transverse light fan diagram of the lens provided in Example 1 in the visible light band;

[0100] like Figure 5 As shown, it is a point diagram of the lens provided in Example 1 in the visible light band;

[0101] like Figure 6 , which is a graph of the optical transfer function (MTF) of the lens provided in Example 2 at room temperature in the visible light band;

[0102] like Figure 7 , which is a diagram of field curvature and distortion of the lens provided in Example 2 in the visible light band;

[0103] like Figure 8 As shown, it is a transverse light fan diagram of the lens provided in Example 2 in the visible light band;

[0104] like Fig. 9 As shown, it is a point diagram of the lens provided in Example 2 in the visible light band.

[0105] from Figure 2 It can be seen that the optical transfer function (MTF) curve of the lens in the visible light part at room temperature is relatively smooth and concentrated, and the average MTF value of the whole field of view (half image height Y'=23.0mm) is above 0.5; it can be seen that the lens provided in Example 1 of the present invention can meet higher imaging requirements;

[0106] from Figure 6 It can be seen that the optical transfer function (MTF) curve of the lens in the visible light part at room temperature is relatively smooth and concentrated, and the average MTF value of the whole field of view (half image height Y'=23.0mm) is above 0.5; it can be seen that the lens provided in Example 2 of the present invention can meet higher imaging requirements;

[0107] from Figure 3 and Figure 7 It can be seen that the field curvature of the lens is controlled within ±0.2mm. Field curvature is also called "image field curvature". When the lens has field curvature, the intersection of the entire light beam does not coincide with the ideal image point. Although a clear image point can be obtained at each specific point, the entire image plane is a curved surface. T stands for meridian field curvature and S stands for sagittal field curvature. The field curvature curve shows the distance from the current focal plane or image plane to the paraxial focal plane as a function of the field of view coordinates. The meridian field curvature data is the distance from the currently determined focal plane to the paraxial focal plane measured along the Z axis, and is measured on the meridian (YZ plane). The sagittal field curvature data measures the distance measured on a plane perpendicular to the meridian plane. The baseline in the schematic diagram is on the optical axis, and the top of the curve represents the maximum field of view (angle or height). No unit is set on the vertical axis because the curve is always normalized with the maximum radial field of view.

[0108] from Figure 3 and Figure 7 It can be seen that the lens distortion is well controlled within -2.5%. Figure 4 Refer to the curves of multiple wavelengths (0.436um, 0.486um, 0.546um, 0.587um and 0.656um) in Figure 4 Generally speaking, lens distortion is actually a general term for the inherent perspective distortion of optical lenses, that is, distortion caused by perspective. This distortion is very detrimental to the image quality of photos. After all, the purpose of photography is to reproduce, not exaggerate. However, because this is an inherent characteristic of the lens (convex lenses converge light, concave lenses diverge light), it cannot be eliminated, but can only be improved. Figure 3 and Figure 7It can be seen that the distortion of the lens provided in Example 1 of the present invention is -2.5%; the distortion of the lens provided in Example 2 of the present invention is -2.4%; the distortion is set in this way to balance the focal length, the field of view angle and the size of the corresponding camera target surface, and the deformation caused by the distortion can be corrected by post-image processing.

[0109] from Figure 4 and Figure 8 It can be seen that the curves in the light fan diagram are relatively concentrated, and the spherical aberration and dispersion of the lens are also well controlled. Figure 4 and Figure 8 In FIG. 1 , EX represents the aberration in the X direction, EY represents the aberration in the Y direction, PX represents the normalized pupil coordinate in the X direction, and PY represents the normalized pupil coordinate in the Y direction.

[0110] from Figure 5 and Fig. 9 It can be seen that the lens spot radius is small and concentrated, and the corresponding aberration and coma are also very good.

[0111] In summary, the embodiment of the present invention provides a full-frame large target surface, low distortion, low-cost, high-definition imaging optical lens. Nine optical lenses with specific structural shapes are used, and they are arranged in sequence from the object side to the image side in a specific order, and through the allocation and combination of the specific optical power of each optical lens, the lens can achieve better distortion control and excellent imaging characteristics.

[0112] The embodiment of the present invention provides a lens and a camera device, wherein the lens is composed of a first negative power lens, a second negative power lens, a first positive power lens, a second positive power lens, a lens group, a fourth negative power lens, a fourth positive power lens and a fifth positive power lens arranged in sequence from the object side to the image side; the image side of the fifth positive power lens includes a filter and an image plane in sequence; the lens group meets the following conditions: Among them, f G1 is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens; the lens group is composed of a third negative power lens and a third positive power lens arranged in sequence from the object side to the image side. In the embodiment of the present invention, 9 lenses with specific focal powers are arranged in sequence from the object side to the image side in a specific order in the lens, and the third negative power lens and the third positive power lens constitute a lens group, and the lens group satisfies: A full-frame optical lens with high resolution, large target area, low distortion, miniaturization and low cost has been realized.

[0113] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0114] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0116] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0117] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A lens, characterized in that: The lens is composed of a first negative power lens, a second negative power lens, a first positive power lens, a second positive power lens, a lens group, a fourth negative power lens, a fourth positive power lens and a fifth positive power lens arranged in sequence from the object side to the image side; the image side of the fifth positive power lens includes a filter and an image plane in sequence; The lens group meets the following conditions: Among them, f G1 is the focal length of the lens group, f is the focal length of the lens, and FOV is the field of view of the lens; The lens group is composed of a third negative power lens and a third positive power lens arranged in sequence from the object side to the image side; The central curvature radius R6 of the image side surface of the first positive power lens and the central curvature radius R7 of the object side surface of the second positive power lens satisfy: or The distance TTL from the object plane side of the first negative power lens to the image plane and the focal length f9 of the fifth positive power lens satisfy the following: TTL / f9≤1.

10.

2. The lens according to claim 1, characterized in that: The first negative power lens is a meniscus lens, and the surface facing the object side is a convex surface; The second negative power lens is a meniscus lens, and the surface facing the object side is a convex surface; The first positive power lens is a biconvex lens; The second positive power lens is a meniscus lens, and a surface thereof facing the object side is a convex surface; The third negative power lens is a meniscus lens, and the surface facing the object side is a convex surface; The third positive power lens is a biconvex lens; The fourth negative power lens is a biconcave lens; The fourth positive power lens is a biconvex lens; The fifth positive power lens is a meniscus lens, and a surface thereof facing the image side is a convex surface.

3. The lens according to claim 1, wherein: The third negative power lens and the third positive power lens form a cemented lens group.

4. The lens according to claim 1, wherein: The focal length f1 of the first negative power lens, the focal length f4 of the second positive power lens and the focal length f8 of the fourth positive power lens satisfy: f1≤-90.5mm; f4≤98.2mm; f8≤69.6mm.

5. The lens according to claim 1, wherein: The Abbe number Vd2 of the second negative power lens, the Abbe number Vd3 of the first positive power lens, and the Abbe number Vd5 of the third negative power lens satisfy: Vd2≤78.6; Vd3≤62.5; Vd5≤26.

4.

6. The lens according to claim 1, wherein: The refractive index Nd2 of the second negative power lens, the refractive index Nd7 of the fourth negative power lens, and the refractive index Nd8 of the fourth positive power lens satisfy: Nd2≤1.65; Nd7≤2.05; Nd8≤1.

98.

7. The lens according to claim 1, wherein: An aperture stop is arranged between the third positive power lens and the fourth negative power lens.

8. A camera device, characterized in that: The imaging device comprises the lens according to any one of claims 1 to 7.

Images