Lens system, imaging module and camera device

Abstract

The application provides a lens system, an imaging module and a camera equipment, and belongs to the optical technical field, and is used for solving the problem that the existing automobile electronic camera imaging mode has high requirements on hardware and algorithms, and the spliced image may have a dead angle. The lens system comprises, in order from the object side to the image side, a catadioptric lens and a lens lens group. The object side surface of the catadioptric lens comprises a first transmission surface and a first internal reflection surface, the first transmission surface is a non-spherical convex surface, and the first internal reflection surface is located in the central region of the first transmission surface. The image side surface of the catadioptric lens comprises a second internal reflection surface and a second transmission surface, the second internal reflection surface is a concave surface, and the second transmission surface is located in the central region of the second internal reflection surface. The lens lens group comprises a plurality of coaxially arranged optical lenses. The lens system can realize image acquisition and recording of the road conditions around the automobile through one lens, and realize 360-degree dead angle-free viewfinder.

Description

Technical Field

[0001] This application belongs to the field of optical technology, specifically relating to a lens system, imaging module and camera device. Background Technology

[0002] Modern imaging devices are widely used in automotive electronic cameras, especially 360-degree surround-view cameras, which have become common equipment for intelligent driver assistance systems. However, current 360-degree surround-view cameras typically use four cameras, placed at the front, rear, left, and right of the car respectively, to capture road condition images from these directions. These images are then stitched together using image stitching algorithms to achieve the so-called 360-degree surround-view effect. This imaging method requires a large number of lenses and places high demands on hardware and algorithms. Furthermore, the stitched images may contain blind spots. Summary of the Invention

[0003] Therefore, the technical problem to be solved by this application is to provide a lens system, imaging module and camera device that can acquire and record images of the road conditions around a car through a single lens, and achieve 360° surround view without blind spots.

[0004] To address the aforementioned problems, a first aspect of this application provides a lens system comprising, from the object side to the image side, a catadioptric lens and a lens assembly. The object-side surface of the catadioptric lens includes a first transmissive surface and a first internal reflective surface. The first transmissive surface is a non-spherical convex surface, and the first internal reflective surface is located in the central region of the first transmissive surface. The image-side surface of the catadioptric lens includes a second internal reflective surface and a second transmissive surface. The second internal reflective surface is concave, and the second transmissive surface is located in the central region of the second internal reflective surface. The lens assembly includes a plurality of optical lenses coaxially arranged.

[0005] Optionally, from the object side to the image side, the lens group sequentially includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The second and fifth lenses have negative optical power. The first, third, fourth, and sixth lenses have positive optical power.

[0006] Optionally, the first lens and the second lens are cemented together to form a first cemented lens group. The fourth lens and the fifth lens are cemented together to form a second cemented lens group.

[0007] Optionally, the effective focal length of the first cemented lens group is f. 12 f 12 The range is -10.0 to 20 mm.

[0008] The effective focal length of the second cemented lens group is f. 45 f 45 >0.

[0009] The effective focal length of the third lens is f3, and the range of f3 is 0 to 15.0 mm.

[0010] The effective focal length of the sixth lens is f6, and the range of f6 is 0 to 20.0 mm.

[0011] Optionally,

[0012] The refractive index of the catadioptric lens is n, and the dispersion coefficient is v. n ranges from 1.50 to 1.65, and v ranges from 45 to 65.

[0013] The first lens has a refractive index of n1 and a dispersion coefficient of v1, where n1 ranges from 1.55 to 1.75 and v1 ranges from 45 to 65.

[0014] The refractive index of the second lens is n2, and the dispersion coefficient is v2, where n2 ranges from 1.65 to 1.95 and v2 ranges from 35 to 55.

[0015] The refractive index of the third lens is n3, and the dispersion coefficient is v3, where n3 ranges from 1.50 to 1.75 and v3 ranges from 45 to 65.

[0016] The fourth lens has a refractive index of n4 and a dispersion coefficient of v4, where n4 ranges from 1.50 to 1.75 and v4 ranges from 45 to 65.

[0017] The fifth lens has a refractive index of n5 and a dispersion coefficient of v5, where n5 ranges from 1.65 to 1.90 and v5 ranges from 20 to 40.

[0018] The sixth lens has a refractive index of n6 and a dispersion coefficient of v6, where n6 ranges from 1.65 to 1.85 and v6 ranges from 45 to 65.

[0019] Optionally, the center thickness of the catadioptric lens is D, and the range of D is 2 to 10.0 mm.

[0020] The optical lens has a center thickness of d and an edge thickness of d', where d ranges from 0.4 to 3.0 mm and d' ranges from 0.25 to 4.0 mm.

[0021] Optionally, the lens material of the catadioptric lens and the lens assembly is glass and / or plastic.

[0022] The refractive index of the lens material in the D band is Nd, and the range of Nd is 1.52 to 1.95.

[0023] Optionally, the effective focal length of the catadioptric lens is f, where f ranges from 0 to 5.0 mm.

[0024] If the effective focal length of the lens system is F, and the distance along the optical axis from the object surface of the catadioptric lens to the imaging plane is TL, then the range of F / TL is -0.1 to -0.02.

[0025] The second aspect provides an imaging module, which includes an image sensor, a filter, and the aforementioned lens system. The image sensor converts the light image on the sensing area into an electrical signal proportional to the light image. The filter, located between the lens system and the sensing area of ​​the image sensor, filters stray light from the light entering the lens system.

[0026] A third aspect provides a camera device, which includes the aforementioned imaging module, lens mount, and electronic components. The imaging module includes an image sensor, a filter, and the aforementioned lens system, which includes a catadioptric lens and a lens group. The lens system is mounted on the lens mount at a preset focusing distance.

[0027] Beneficial Effects: The lens system provided in this application includes a catadioptric lens and a lens assembly. The object-side surface of the catadioptric lens includes a first transmission surface and a first internal reflection surface, and the image-side surface of the catadioptric lens includes a second internal reflection surface and a second transmission surface. The first transmission surface is a non-spherical convex surface, and the second internal reflection surface is a concave surface. The first internal reflection surface is located in the central region of the first transmission surface, and the second transmission surface is located in the central region of the second internal reflection surface. With this configuration, light beams with different incident angles at the object side can enter the catadioptric lens through the first transmission surface, be reflected by the second internal reflection surface back to the first internal reflection surface, and then exit through the second transmission surface after further reflection. This invention, through the combined action of the first transmission surface, the first internal reflection surface, the second internal reflection surface, and the second transmission surface, can compress the field of view and couple light beams with different incident angles into the lens assembly. The lens assembly includes multiple optical lenses, and the combined action of these multiple optical lenses can balance the phase difference in the lens system and focus the light beam onto the imaging plane to achieve object imaging. This application can achieve a 360° surround view imaging effect with only one lens system, thereby reducing the number of components, lowering costs, and eliminating the need for image stitching, thus reducing the imaging difficulty. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the lens system in some embodiments of this application;

[0029] Figure 2 This is a schematic diagram of a catadioptric lens in some embodiments of this application;

[0030] Figure 3 This is a schematic diagram of the optical path of the imaging module in some embodiments of this application;

[0031] Figure 4This is a modulation transfer function curve of the imaging module in some embodiments of this application;

[0032] Figure 5 This is a contrast diagram of each field of view of the imaging module in some embodiments of this application;

[0033] Figure 6 The diagram shows the field curvature and F-θ distortion curves of the imaging module in some embodiments of this application;

[0034] Figure 7 This is a schematic diagram illustrating the application of the camera device in some embodiments of this application;

[0035] Figure 8 This is a schematic diagram of the imaging effect of the camera device in some embodiments of this application. Detailed Implementation

[0036] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0040] Firstly, this embodiment provides a lens system. Figure 1 This is a schematic diagram of the lens system in this embodiment. Figure 1 As shown, the lens system, from the object side to the image side, includes a catadioptric lens 1 and a lens group 2 in sequence.

[0041] like Figure 2 As shown, the object-side surface of the catadioptric lens 1 includes a first transmission surface S1 and a first internal reflection surface S3. The first transmission surface S1 is a non-spherical convex surface, and the first internal reflection surface S3 is located in the central region of the first transmission surface S1. The image-side surface of the catadioptric lens 1 includes a second internal reflection surface S2 and a second transmission surface S4. The second internal reflection surface S2 is a concave surface, and the second transmission surface S4 is located in the central region of the second internal reflection surface S2.

[0042] In some examples, the first transmission surface S1 is aspherical. This configuration allows the catadioptric lens 1 to have a better optical imaging coefficient. However, it is understood that in other embodiments, the first transmission surface S1 may also be spherical.

[0043] In some examples, the catadioptric lens 1 is a rotating body, so that light circumferentially rotating 360 degrees around the central axis of the catadioptric lens 1 can enter the catadioptric lens 1 through the first transmission surface S1, be reflected by the second inner reflection surface S2 onto the first inner reflection surface S3, and then be reflected by the first inner reflection surface S3 before entering the lens assembly 2 through the second transmission surface S4.

[0044] In some examples, the first internal reflecting surface S3 and the second transmitting surface S4 are planes perpendicular to the optical axis.

[0045] The catadioptric lens 1 of this embodiment has positive optical power, which can compress the field of view and couple beams with different incident angles into the lens group 2 behind the catadioptric lens 1 through two transmissions and two reflections.

[0046] See Figure 1 Lens assembly 2 includes multiple optical lenses arranged coaxially.

[0047] In some examples, the object-side and image-side surfaces of each optical lens can be either spherical or aspherical.

[0048] In some examples, multiple optical lenses in catadioptric lens 1 and lens group 2 are connected by lens barrels and spacers.

[0049] The lens assembly 2 in this embodiment is used to balance various aberrations of the optical system and can focus the light beam onto the imaging plane to image the target object.

[0050] The lens system provided in this embodiment includes a catadioptric lens 1 and a lens assembly 2. The object-side surface of the catadioptric lens 1 includes a first transmission surface S1 and a first internal reflection surface S3, and the image-side surface of the catadioptric lens 1 includes a second internal reflection surface S2 and a second transmission surface S4. The first transmission surface S1 is a non-spherical convex surface, the second internal reflection surface S2 is a concave surface, and the first internal reflection surface S3 is located in the central region of the first transmission surface S1, while the second transmission surface S4 is located in the central region of the second internal reflection surface S2. With this configuration, light beams with different incident angles on the object side can enter the catadioptric lens 1 through the first transmission surface S1, be reflected by the second internal reflection surface S2 to the first internal reflection surface S3, and then, after reflection by the first internal reflection surface S3, enter the lens assembly 2 through the second transmission surface S4. This invention, through the combined action of the first transmission surface S1, the first internal reflection surface S3, the second internal reflection surface S2, and the second transmission surface S4, can compress the field of view and couple light beams with different incident angles into the lens assembly 2. Lens assembly 2 includes multiple optical lenses. The combined effect of these lenses balances the phase difference within the lens system and focuses the light beam onto the imaging plane, thus achieving object imaging. This embodiment achieves 360° surround-view imaging with only one lens system, thereby reducing the number of components, lowering costs, and eliminating the need for image stitching, thus reducing imaging difficulty.

[0051] In some embodiments, the refractive index of the catadioptric lens 1 is n, and the dispersion coefficient is v. Wherein, n ranges from 1.50 to 1.65, and v ranges from 45 to 65.

[0052] In some examples, such as Figure 2 As shown, the refractive index n of the catadioptric lens 1 is 1.53, and the dispersion index v is 56.0. This configuration satisfies the ability of the catadioptric lens 1 to compress the field of view while also achieving good image quality.

[0053] Understandably, a larger dispersion coefficient (Abbe number) results in less noticeable chromatic aberration and better image quality, while a smaller dispersion coefficient (Abbe number) leads to more noticeable chromatic aberration and poorer image quality. Generally, the dispersion coefficient (Abbe number) is inversely proportional to the lens's refractive index; that is, a larger refractive index results in a smaller dispersion coefficient (Abbe number) and more noticeable chromatic aberration. The catadioptric lens 1 in this embodiment can maintain image quality while satisfying the requirement for field-of-view compression.

[0054] In some embodiments, the effective focal length of the catadioptric lens 1 is f, and the range of f is 0 to 5.0 mm.

[0055] The effective focal length of the lens system is F, and the distance along the optical axis from the object surface of the catadioptric lens 1 to the imaging plane is TL. Then the range of F / TL is -0.1 to -0.02.

[0056] It should be noted that the effective focal length refers to the distance from the center of the lens to the focal point. If the focal length is too short, the field of view will be too large, leading to difficulty in controlling distortion and the principal ray exit angle, resulting in low relative illumination, severe lens curvature, and difficulty in phase correction, making design challenging. If the focal length is too long, the lens will be too long, hindering system miniaturization, and the field of view will be too small to meet user needs.

[0057] This embodiment is configured in such a way that a large field of view can be obtained, while ensuring the best imaging quality while maintaining a compact structure.

[0058] In some embodiments, the center thickness of the catadioptric lens 1 is D, and D ranges from 2 to 10.0 mm. The center thickness of the optical lens is d, and the edge thickness is d', wherein d ranges from 0.4 to 3.0 mm, and d' ranges from 0.25 to 4.0 mm.

[0059] As is understandable, center thickness measures the material thickness at the center of the lens. Center thickness is measured via the lens's mechanical axis, which is defined as the axis between the lens's outer edges. Variations in the lens's center thickness affect optical performance because the center thickness and its radius of curvature determine the optical path length of light passing through the lens.

[0060] The lens system in this embodiment can ensure that the path of the light beam entering the catadioptric lens meets the usage requirements, and can also better meet the requirements of miniaturization of the camera.

[0061] In some embodiments, such as Figure 1 As shown, from the object side to the image side, the lens group 2 sequentially includes: a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, a fifth lens 25, and a sixth lens 26. The second lens 22 and the fifth lens 25 have negative optical power. The first lens 21, the third lens 23, the fourth lens 24, and the sixth lens 26 have positive optical power.

[0062] As can be understood, optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam. It characterizes the ability of an optical system to deflect light rays and is commonly represented by the letter φ. The larger the value of φ, the more pronounced the refraction of the parallel beam. When φ > 0, the refraction is converging; when φ < 0, the refraction is diverging.

[0063] In this embodiment, the second lens 22 and the fifth lens 25 have negative optical power, while the first lens 21, the third lens 23, the fourth lens 24, and the sixth lens 26 have positive optical power. Through the combined effect of the lenses, various aberrations of the optical system can be balanced, and the light beam can be focused onto the image sensor to image the target.

[0064] In some embodiments, the first lens 21 and the second lens 22 are cemented together to form a first cemented lens group. The fourth lens 24 and the fifth lens 25 are cemented together to form a second cemented lens group.

[0065] In some examples, the effective focal length of the first cemented lens group is f. 12 f 12 The range is -10.0 to 20 mm. The effective focal length of the second cemented lens group is f. 45 f 45 >0. This setting allows for good image quality while maintaining a compact structure.

[0066] This embodiment achieves a short focal length, high magnification, and good image quality by using two lenses to form a lens group.

[0067] In some embodiments, the effective focal length of the third lens 23 is f3, and the range of f3 is 0 to 15.0 mm. The effective focal length of the sixth lens is f6, and the range of f6 is 0 to 20.0 mm.

[0068] In some examples, such as Figure 1 As shown, the image-side and object-side surfaces of the third lens 23 are both aspherical convex surfaces, and the object-side surface of the sixth lens is also an aspherical convex surface. This configuration can converge the light beam in the system, reduce distortion at the edges of the field of view, and improve sharpness.

[0069] This embodiment can improve the clarity of surround view imaging while meeting the requirement of lens miniaturization.

[0070] In some embodiments, the first lens 21 has a refractive index of n1 and a dispersion coefficient of v1, wherein n1 ranges from 1.55 to 1.75 and v1 ranges from 45 to 65. The second lens 22 has a refractive index of n2 and a dispersion coefficient of v2, wherein n2 ranges from 1.65 to 1.95 and v2 ranges from 35 to 55. The third lens 23 has a refractive index of n3 and a dispersion coefficient of v3, wherein n3 ranges from 1.50 to 1.75 and v3 ranges from 45 to 65. The fourth lens 24 has a refractive index of n4 and a dispersion coefficient of v4, wherein n4 ranges from 1.50 to 1.75 and v4 ranges from 45 to 65. The fifth lens 25 has a refractive index of n5 and a dispersion coefficient of v5, wherein n5 ranges from 1.65 to 1.90 and v5 ranges from 20 to 40. The sixth lens 26 has a refractive index of n6 and a dispersion coefficient of v6, where n6 ranges from 1.65 to 1.85 and v6 ranges from 45 to 65.

[0071] In some examples, such as Figure 1As shown, the refractive index n of the catadioptric lens 1 is 1.53, and the dispersion index v is 56.0; the refractive index of the first lens 21 is 1.62, and the dispersion is 56.7; the refractive index of the second lens 22 is 1.86, and the dispersion is 36.6; the refractive index of the third lens 23 is 1.58, and the dispersion is 52.7; the refractive index of the fourth lens 24 is 1.53, and the dispersion is 60.5; the refractive index of the fifth lens 25 is 1.85, and the dispersion is 23.8; and the refractive index of the sixth lens 26 is 1.82, and the dispersion is 46.6.

[0072] It should be noted that traditional fisheye lenses exhibit significant negative distortion at the edges of the field of view, with the resolution of detailed pixels decreasing progressively from the center to the edges of the image. However, the lens system of this embodiment, through the combined action of the catadioptric lens 1 and the first lens 21, second lens 22, third lens 23, fourth lens 24, fifth lens 25, and sixth lens 26, allows the number of pixels in the image to increase from the center to the edges of the field of view, resulting in higher resolution when the image is unfolded.

[0073] In some embodiments, the lens materials of the catadioptric lens 1 and the lens assembly 2 are glass and / or plastic.

[0074] The refractive index of the lens material in the D band (587nm band) is Nd, and the range of Nd is 1.52 to 1.95.

[0075] Glass lenses possess properties such as high temperature resistance, corrosion resistance, and scratch resistance, protecting the entire lens system from scratches during assembly, transportation, and use. They are also resistant to wind damage and deterioration in harsh environments such as high and low temperatures, strong light, and sandstorms, thus extending the lifespan of the lens system. Plastic lenses can be made from materials such as polymethyl methacrylate (i.e., plexiglass, commonly known as acrylic), polycarbonate, and cyclic olefin copolymers.

[0076] In this embodiment, the catadioptric lens 1 and the subsequent lens assembly 2 are made of a combination of plastic and glass lenses, which reduces production costs, improves the thermal stability and corrosion resistance of the lens system, and reduces the impact of excessively cold or hot temperatures on the focal length of the lens system.

[0077] In some embodiments, the lens system further includes at least one aperture stop. The aperture stop is located between two adjacent lenses.

[0078] In some examples, see Figure 1 The aperture stop is positioned between the catadioptric lens 1 and the first lens 21. It is understood that in other embodiments, the aperture stop may also be positioned between any two other adjacent lenses, depending on actual needs.

[0079] The lens system in this embodiment is equipped with an aperture stop, which can reduce spherical aberration and improve image sharpness.

[0080] In some embodiments, the aperture coefficient of the lens system is Fno, and Fno < 2.0.

[0081] As is understandable, the aperture size of a lens is expressed using the aperture coefficient, which is the ratio of the lens's focal length to the diameter of the aperture opening. Therefore, for lenses with the same focal length, a smaller aperture coefficient indicates a larger aperture opening, and a larger aperture coefficient indicates a smaller aperture opening.

[0082] The lens system of this embodiment has an aperture coefficient Fno < 2.0, which enables the imaging surface to have sufficient and appropriate illumination over a large field of view.

[0083] Secondly, this embodiment also provides an imaging module. Figure 3 This is a schematic diagram of the optical path of the imaging module in this embodiment. Figure 3 As shown, the imaging module includes: an image sensor 4, a filter 3, and the aforementioned lens system. The image sensor 4 is used to convert the light image on the sensing area into an electrical signal that is proportional to the light image. The filter 3 is used to filter stray light from the light entering the lens system and is located between the lens system and the sensing area of ​​the image sensor 4.

[0084] The imaging module in this embodiment can operate at F / 2.0 and achieve a field of view of 45 degrees to 101 degrees. See also... Figure 3 The specific surface coefficients of each surface are shown in Table 1.

[0085] Table 1:

[0086]

[0087]

[0088] The equations for the aspherical curves of the above lenses are expressed as follows:

[0089]

[0090] Where z is the position value along the optical axis at a height of h, with the vertex of the surface as a reference; c is the curvature of the lens surface near the optical axis, and is the reciprocal of the radius of curvature (R) (c = 1 / R), R is the radius of curvature of the lens surface near the optical axis, h is the perpendicular distance of the lens surface from the optical axis, k is the conic constant, and A2, A4, A6, A8, A10, A12, A14, A16, ... are higher-order aspherical coefficients.

[0091] The aspherical coefficients are shown in Table 2.

[0092] Table 2:

[0093]

[0094] The modulation transfer function (MTF) curve of the imaging module in this embodiment is shown in the figure below. Figure 4 As shown, the horizontal axis represents spatial frequency (unit: period / mm), and the vertical axis represents OTF modulus. The curves represent the tangential and vector curves at positions of 45 degrees, 60 degrees, 80 degrees, 101 degrees, -45 degrees, -60 degrees, -80 degrees, and -101 degrees, respectively. Figure 4 As shown, with the increase of spatial frequency, the difference between the tangential and vector curves at each location becomes greater, and the OTF modulus is above 0.3.

[0095] The contrast of each field of view of the imaging module in this embodiment is as follows: Figure 5 As shown, the horizontal axis represents the Y-field (unit: degrees), and the vertical axis represents the relative illumination. Figure 5 As shown, the relative illuminance is above 0.9 between 0 and 101 degrees, and the relative illuminance shows an upward trend before 90.9 degrees.

[0096] The field curvature and F-θ distortion curves of the imaging module in this embodiment are as follows: Figure 6 As shown, the left side is the field curvature curve, and the right side is the distortion curve. Figure 6 As shown, the field curvature of the imaging module in this embodiment is within ±10μm, and the positive and negative distortions are both much less than 2%, which are almost imperceptible.

[0097] The imaging module provided in this embodiment uses seven lenses, and the arrangement of these lenses forms a 360-degree panoramic high-definition lens, reducing its production cost. (See also...) Figures 4-6 Through the combined action of the catadioptric lens 1 and the subsequent lens group 2, as the field of view increases from 45 degrees to 101 degrees, the lens exhibits a positive distortion opposite to that of ordinary lenses, resulting in richer image details at the edges of the field of view and significantly enhanced edge sharpness. The high-definition panoramic lens allows users to directly view a complete 360-degree scene. Its structure is simple and its manufacturing cost is low.

[0098] The optical path in the imaging module of this embodiment is as follows: Figure 3As shown, light beams with different incident angles can enter the catadioptric lens 1 through the first transmission surface S1, and be reflected by the second inner reflection surface S2 onto the first inner reflection surface S3. After being reflected again by the first inner reflection surface S3, they exit through the second transmission surface S4. Subsequently, through the combined action of the first lens 21, the second lens 22, the third lens 23, the fourth lens 24, the fifth lens 25, and the sixth lens 26, the light beam passes through the filter 3 and is focused onto the image sensor 4 to image the target.

[0099] The imaging module of this embodiment has an optical length of less than 28mm and a maximum optical aperture of less than 21mm. Therefore, the height of the high-definition panoramic camera module can be made very compact, making it suitable for use as a surveillance lens and video conferencing device, effectively meeting the miniaturization requirements of cameras. Its horizontal field of view reaches 360 degrees, with a downward angle of 45 degrees and an upward angle of 101 degrees, satisfying a wide framing range. While lens distortion is well controlled in this embodiment, the entire lens can meet the resolution requirements of high-definition detectors such as 4K, 1080P, and 720P.

[0100] In some embodiments, at least one surface of the filter 3 is coated with an infrared cutoff film.

[0101] It should be noted that an infrared cut-off film is an optical thin film that blocks the transmission of infrared wavelengths. In this embodiment, by coating the filter 3 with an infrared cut-off film, infrared light that interferes with image quality can be blocked, making the resulting image more in line with the optimal perception of the human eye.

[0102] Thirdly, this embodiment also provides a camera device 100. Figure 7 This is a schematic diagram illustrating the application of the camera device 100 in this embodiment. The camera device 100 includes: the imaging module, lens mount, and electronic components described above. The imaging module includes an image sensor, a filter, and the lens system described above. The lens system includes a catadioptric lens and a lens group. The lens system is mounted on the lens mount according to a preset focusing distance. Figure 7 As shown, the camera device 100 of this embodiment is placed on the roof of a car. With just one lens, it can capture a 360° panoramic view of the car without blind spots, allowing for image acquisition and recording of the road conditions around the vehicle. Combined with specific image cropping and processing methods, the target subject can be displayed in sections on a split screen. This camera device 100 has the unique characteristic of simultaneous 360-degree observation, providing a clear view of all people and activities, improving target confirmation speed, preventing the loss of unexpected events, and truly achieving panoramic monitoring. Its imaging effect is as follows: Figure 8 As shown.

[0103] It should be noted that the camera device 100 in this embodiment can be used not only as an electronic camera for automobiles, but also in virtual reality devices or augmented reality devices. For example, black boxes, around-view monitoring (AVM) systems, or rear-view cameras. Furthermore, it can be applied to various action camera devices, such as drones or camcorders used for leisure or sports activities, and various surveillance cameras. This embodiment does not impose further limitations in this regard.

[0104] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0105] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A lens system, characterized in that, The sequence from the object side to the image side consists of a catadioptric lens and a lens assembly. The object-side surface of the catadioptric lens includes a first transmission surface and a first internal reflection surface. The first transmission surface is a non-spherical convex surface, and the first internal reflection surface is located in the central region of the first transmission surface. The image-side surface of the catadioptric lens includes a second internal reflection surface and a second transmission surface. The second internal reflection surface is a concave surface, and the second transmission surface is located in the central region of the second internal reflection surface. The first internal reflection surface and the second transmission surface are planes perpendicular to the optical axis. From object to image, the lens group consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; the second lens and the fifth lens have negative optical power; the first lens, the third lens, the fourth lens, and the sixth lens have positive optical power; the first lens and the second lens are cemented together to form a first cemented lens group; the fourth lens and the fifth lens are cemented together to form a second cemented lens group; the effective focal length of the first cemented lens group is f. 12 f 12 The range is -10.0~20mm; the effective focal length of the second cemented lens group is f. 45 f 45 >0; the effective focal length of the third lens is f3, and the range of f3 is 0~15.0mm; the effective focal length of the sixth lens is f6, and the range of f6 is 0~20.0mm.

2. The lens system according to claim 1, characterized in that, The refractive index of the catadioptric lens is n, and the dispersion coefficient is v; wherein, n ranges from 1.50 to 1.65, and v ranges from 45 to 65. The first lens has a refractive index of n1 and a dispersion coefficient of v1, wherein n1 ranges from 1.55 to 1.75 and v1 ranges from 45 to 65. The second lens has a refractive index of n2 and a dispersion coefficient of v2, wherein n2 ranges from 1.65 to 1.95 and v2 ranges from 35 to 55. The third lens has a refractive index of n3 and a dispersion coefficient of v3, wherein n3 ranges from 1.50 to 1.75 and v3 ranges from 45 to 65. The fourth lens has a refractive index of n4 and a dispersion coefficient of v4, wherein n4 ranges from 1.50 to 1.75 and v4 ranges from 45 to 65. The fifth lens has a refractive index of n5 and a dispersion coefficient of v5, wherein n5 ranges from 1.65 to 1.90 and v5 ranges from 20 to 40. The sixth lens has a refractive index of n6 and a dispersion coefficient of v6, wherein n6 ranges from 1.65 to 1.85 and v6 ranges from 45 to 65.

3. The lens system according to claim 1, characterized in that, The center thickness of the catadioptric lens is D, and the range of D is 2~10.0 mm; The lens group has a center thickness of d and an edge thickness of d', where d ranges from 0.4 to 3.0 mm and d' ranges from 0.25 to 4.0 mm.

4. The lens system according to claim 1, characterized in that, The lens materials of the catadioptric lens and the lens assembly are glass and / or plastic; The refractive index of the lens material in the D band is Nd, and the range of Nd is 1.52~1.

95.

5. The lens system according to claim 1, characterized in that, The effective focal length of the catadioptric lens is f, and the range of f is 0~5.0mm; The effective focal length of the lens system is F, and the distance along the optical axis from the object surface of the catadioptric lens to the imaging surface is TL. Then the range of F / TL is -0.1 to -0.

02.

6. An imaging module, characterized in that, include: Image sensor, filter and lens system as described in any one of claims 1 to 5; The image sensor is used to convert the light image on the sensing area into an electrical signal that is proportional to the light image. The filter is used to filter stray light in the light entering the lens system and is located between the lens system and the sensing area of ​​the image sensor.

7. A camera device, characterized in that, include: The imaging module, lens mount, and electronic components as described in claim 6; The lens system is mounted on the lens base at a preset focusing distance.

Images