Lens and imaging device

Abstract

The utility model discloses a lens and a camera device, and relates to the technical field of camera products, the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a lens assembly which are sequentially arranged from the image side to the object side along the same optical axis, and the first lens, the second lens and the fourth lens have negative focal lengths. The third lens, the fifth lens and the lens assembly have positive focal lengths. According to the technical scheme provided by the utility model, the problem that a local image is not clear when an existing lens is used for imaging is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of camera products, in particular to a lens and a camera device. Background Art

[0002] With the development of science and technology and the progress of society, video surveillance equipment is also constantly reforming and upgrading. In order to meet people's demand for "visible, clear, and miniaturized" video surveillance, as well as the consumption needs of the Internet of Things and 5G big data, video surveillance technology needs to have the characteristics of ultra-high network speed, ultra-low latency, and ultra-wide connection, while also ensuring low power consumption and low cost of the terminal. In the fields of smart home, Internet of Things, smart city, smart transportation, environmental monitoring, etc., video surveillance technology plays an important role, especially in the field of new energy vehicles, where video surveillance technology plays a vital role.

[0003] However, the video surveillance products currently on the market, especially fisheye lenses, cannot fully meet these needs. These products often have problems with optical accuracy and are prone to insufficient image clarity during the monitoring process. For example, sometimes the image is not clear around the edges or in a corner, which leads to inaccurate monitoring results. Utility Model Content

[0004] The main purpose of the utility model is to provide a lens and a camera device, aiming to solve the problem that a local image is not clear when imaging with an existing lens.

[0005] To achieve the above-mentioned purpose, the lens proposed in the utility model includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a lens assembly which are arranged in sequence from the image side to the object side along the same optical axis, and the first lens, the second lens and the fourth lens have a negative focal length, and the third lens, the fifth lens and the lens assembly have a positive focal length.

[0006] In one embodiment, the lens assembly includes a sixth lens and a seventh lens having different refractive indices, and the sixth lens and the seventh lens are bonded to each other to form a cemented lens.

[0007] In one embodiment, the image side surfaces of the first lens, the second lens and the fourth lens are all convex surfaces, and the object side surfaces of the first lens, the second lens and the fourth lens are all concave surfaces; the image side surfaces of the third lens and the seventh lens are all concave surfaces, and the object side surfaces of the third lens and the seventh lens are all convex surfaces; the fifth lens and the sixth lens are both biconvex lenses.

[0008] In one implementation, the third lens and the seventh lens are both made of a material with a high refractive index.

[0009] In one embodiment, the first lens and the fourth lens are both made of a material with a low dispersion coefficient.

[0010] In one embodiment, edges of the first lens, the second lens, and the third lens are all provided with cut edges.

[0011] In one embodiment, the lens further includes an aperture stop, and the aperture stop is disposed between the fourth lens and the fifth lens.

[0012] In one embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the lens assembly are all spaced apart from each other.

[0013] The utility model also provides a camera device, which includes the lens described in any one of the above embodiments.

[0014] In the technical solution of the utility model, by reasonably setting the positions of the first lens, the second lens and the fourth lens with negative focal length and the third lens, the fifth lens and the lens assembly with positive focal length, various aberrations, such as spherical aberration, coma, astigmatism, etc., can be effectively compensated, so as to obtain a clear image with high resolution and low distortion in the entire field of view. In addition, the use of a lens with a negative focal length helps to reduce the overall length of the lens, making the lens structure more compact, and maintaining good imaging performance while reducing the volume. The lens with a negative focal length can provide a wider field of view, and can monitor images in a wider range. The combination of positive focal length lenses helps to achieve a smaller minimum focusing distance, provides good close-up capability, can magnify a part of the monitoring image, and improve the overall and local clarity of the monitoring image. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0016] Figure 1 A schematic structural diagram of an embodiment of a lens provided by the utility model;

[0017] Figure 2 An MTF curve diagram of an embodiment of a lens provided by the utility model;

[0018] Figure 3 A through-focus MTF curve diagram of another embodiment of the lens provided by the utility model;

[0019] Figure 4 A spot diagram of another embodiment of the lens provided by the utility model;

[0020] Figure 5 A relative illumination curve diagram of another embodiment of the lens provided by the utility model;

[0021] Figure 6 A vertical axis chromatic aberration curve diagram of yet another embodiment of the lens provided by the utility model.

[0022] Description of Figure Numbers:

[0023] 100. Lens; 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Edge cutting.

[0024] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0028] The video surveillance products on the market, especially fisheye lenses, cannot fully meet these needs. These products often have the problem of optical accuracy cannot be guaranteed, and the image clarity is often insufficient during the monitoring process. For example, sometimes the image around or in a corner is not clear, which leads to inaccurate monitoring results.

[0029] Based on the above shortcomings, the utility model provides a lens.

[0030] See also Figure 1 In one embodiment of the utility model, the lens 100 includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a lens assembly arranged in sequence from the image side to the object side along the same optical axis, and the first lens 1, the second lens 2 and the fourth lens 4 have a negative focal length, and the third lens 3, the fifth lens 5 and the lens assembly have a positive focal length.

[0031] In the technical solution of the utility model, by reasonably setting the positions of the first lens 1, the second lens 2 and the fourth lens 4 with negative focal length and the third lens 3, the fifth lens 5 and the lens assembly with positive focal length, various aberrations such as spherical aberration, coma, astigmatism, etc. can be effectively compensated, so as to obtain a clear image with high resolution and low distortion in the entire field of view. In addition, the use of a lens with a negative focal length helps to reduce the overall length of the lens 100, making the structure of the lens 100 more compact, and can maintain good imaging performance while reducing the volume. The lens with a negative focal length can provide a wider field of view, and can monitor images in a wider range. The combination of positive focal length lenses helps to achieve a smaller minimum focusing distance, provides good close-up capability, can magnify a part of the monitoring image, and improve the overall and local clarity of the monitoring image.

[0032] In the embodiments of the present invention, please refer to Figure 1 , the lens assembly includes a sixth lens 6 and a seventh lens 7 with different refractive indices, and the sixth lens 6 and the seventh lens 7 are bonded to each other to form a cemented lens. By using lenses with different refractive indices and bonding them together to form a composite optical lens 100 of a lens assembly, the imaging effect of high and low temperatures is ensured, and aberrations in the optical system, such as spherical aberration and dispersion, can be reduced or eliminated. For example, a combination of flint glass and crown glass can be used to improve image quality. In addition, the use of different optical materials may also have a higher absorption of light of a specific wavelength. By bonding different lenses, the transmittance in the entire band can be improved. Moreover, by selecting the concave and convex of different lenses for combination, the deformation and refractive index changes caused by high and low temperatures can be compensated, and the optical properties of the lens group, such as focal length, aperture, etc., can be accurately controlled.

[0033] In the embodiments of the present invention, please refer to Figures 1 to 4 , the image side surfaces of the first lens 1, the second lens 2 and the fourth lens 4 are all convex, and the object side surfaces of the first lens 1, the second lens 2 and the fourth lens 4 are all concave, so that the three lenses have negative focal lengths, which can effectively reduce the volume of the lens 100, reduce the weight, and provide a larger field of view, so that the shooting range is wider. In addition, this design can also effectively correct aberrations and improve imaging quality. The image side surfaces of the third lens 3 and the seventh lens 7 are all concave, and the object side surfaces of the third lens 3 and the seventh lens 7 are all convex, so that the two lenses have positive focal lengths, can provide good imaging quality, and make the captured images clear and less distorted. At the same time, this design can also effectively control dispersion and aberrations to ensure the accuracy of the color of the picture. The fifth lens 5 and the sixth lens 6 are both biconvex lenses, so that the two lenses have positive focal lengths and can provide good imaging quality. At the same time, the biconvex lenses can effectively control spherical aberration and coma, making the picture clearer and the color more realistic. The lens 100 uses six different lenses, each of which has its own unique shape and function, and can work together to achieve the best imaging effect.

[0034] In the embodiments of the present invention, please refer to Figures 1 to 3 , the third lens 3 and the seventh lens 7 are both made of high refractive index materials. High refractive index materials have a larger refractive index, which can focus light more effectively, thereby improving the image quality, and also play a certain role in image telecentricity. In an optical system, the function of the focusing group is to collect and focus the light entering the system so that it forms a clear image on the image plane. By using high refractive index materials, the focusing group can complete this task more effectively and achieve high-quality imaging effects.

[0035] In the embodiments of the present invention, please refer to Figure 6 , the first lens 1 and the fourth lens 4 are both made of low dispersion coefficient materials, which can correct chromatic aberration and help improve the imaging performance of the optical system. In the optical system, the two lenses are located in different positions and have different functions, but they jointly participate in the refraction and focusing process of light. By using low dispersion coefficient materials, the two lenses can more effectively complete the refraction and focusing tasks of light, reduce chromatic aberration, and achieve high-quality imaging effects.

[0036] In the embodiments of the present invention, please refer to Figure 1 , Figure 4 and Figure 5, the edges of the first lens 1, the second lens 2 and the third lens 3 are all provided with a cutting edge 8, and the design of the cutting edge 8 helps to reduce aberrations in the edge area, such as vignetting and edge dark angle. This can ensure the consistency and clarity of the image from the center to the edge, and improve the overall imaging quality. In addition, the cutting edge 8 design of the lens edge helps to improve the alignment accuracy of the lens assembly during the assembly process of the lens 100, thereby reducing assembly time and improving production efficiency.

[0037] In an embodiment of the present invention, the lens 100 further includes an aperture, which is disposed between the fourth lens 4 and the fifth lens 5, and can effectively reduce stray light and unnecessary light, ensuring that only light beneficial to imaging passes through, thereby improving the clarity and uniformity of imaging.

[0038] In the embodiments of the present invention, please refer to Figure 1 , the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5 and the lens assembly are spaced apart so that each lens can fully exert its function without interfering with each other, thereby achieving the best imaging effect. First, the spacing setting can effectively correct aberrations and improve imaging quality. Secondly, this design can make the light transmission of each lens more efficient, improve light transmittance, reduce halo and ghosting phenomena, and make the picture more transparent and delicate.

[0039] Of course, in other embodiments, the above-mentioned embodiments can also be combined and arranged, and the obtained optical lens 100 is a fixed-focus lens 100, with an angle of 190 degrees, a focal length of 1.08 and 1 / 4 of the target surface, and an optical total length of 17.38mm, while ensuring high resolution; adopting a temperature compensation design, it works in an environment of -40℃~+80℃ without defocusing; adopting mutual compensation of positive and negative lens focal lengths, not only ensures the performance of the optical system, but also reduces the processing cost of parts, simplifies the structure, reduces weight, and is conducive to mass production, meeting market demand; while using low-dispersion materials, it can also improve the image quality. Table 1 shows the surface type, radius of curvature, thickness / distance, refractive index, dispersion coefficient and focal length of each lens in the lens 100, where the units of radius of curvature and thickness are both millimeters (mm).

[0040] Table 1:

[0041] Face number Surface type Radius of curvature Thickness / distance Refractive Index Dispersion coefficient focal length S1 Spherical 13.12 0.8 1.671028 47.281988 -11.001 S2 Spherical 4.62 2.373 S3 Spherical 8.254 0.683 1.755002 52.329298 -4.14 S4 Spherical 2.192 1.673 S5 Spherical -11.609 1.245 1.808108 22.690566 14.287 S6 Spherical -6.091 0.1 S7 Spherical 10.069 0.973 1.456500 90.269745 -4.065 S8 Spherical 1.522 0.3 STOP unlimited In 0.1 S10 Spherical 4.137 3.791 1.658439 50.866500 3.1 S11 Spherical -2.578 0.1 S12 Spherical 6.187 2.026 1.696801 56.199825 646.815 S13 Spherical -1.99 0.6 1.945958 17.943914 38.435 S14 Spherical -6.415 1.82

[0042] The present invention further provides a camera device, which includes the lens 100 described in any of the above embodiments. The specific structure of the lens 100 refers to the above embodiments. Since the camera device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0043] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A lens, characterized in that: The lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a lens assembly which are arranged in sequence from the image side to the object side along the same optical axis, and the first lens, the second lens and the fourth lens have a negative focal length, and the third lens, the fifth lens and the lens assembly have a positive focal length.

2. The lens according to claim 1, characterized in that: The lens assembly includes a sixth lens and a seventh lens having different refractive indices, and the sixth lens and the seventh lens are bonded to each other to form a cemented lens.

3. The lens according to claim 2, characterized in that: The image side surfaces of the first lens, the second lens and the fourth lens are all convex surfaces, and the object side surfaces of the first lens, the second lens and the fourth lens are all concave surfaces; the image side surfaces of the third lens and the seventh lens are all concave surfaces, and the object side surfaces of the third lens and the seventh lens are all convex surfaces; the fifth lens and the sixth lens are both biconvex lenses.

4. The lens according to claim 2, characterized in that: The third lens and the seventh lens are both made of materials with high refractive index.

5. The lens according to claim 1, wherein: The first lens and the fourth lens are both made of materials with low dispersion coefficient.

6. The lens according to claim 1, wherein: The edges of the first lens, the second lens and the third lens are all provided with cut edges.

7. The lens according to claim 1, wherein: The lens further includes an aperture stop, and the aperture stop is arranged between the fourth lens and the fifth lens.

8. The lens according to any one of claims 1 to 7, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the lens assembly are all arranged at intervals.

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

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