178-degree ultra-wide-angle optical imaging system

Abstract

The invention discloses a 178-degree ultra-wide-angle optical imaging system, which comprises an optical lens and a photoelectric conversion device, and is characterized in that the lens part comprises eight lenses, and the lenses are sequentially a negative lens, a negative lens, a negative lens, a positive lens, a positive lens, a positive lens, a negative lens and a negative lens along the light incidence direction; the focal length of the lens is 13.66 mm, the F number is 5.46, the field angle is 178 degrees, and the total optical length of the system is 151.87 mm; the lens works in a visible light wave band, is combined with a photoelectric conversion device to form an optical imaging system, is mainly configured at the front end of a video monitoring system, monitors an area through a single-path imaging unit, and is used for collecting panoramic images of an entrance, a square, a perimeter and a large-space scene; in the lens design process, the cost factor is fully considered, and eight spherical lenses are adopted; in the lens design process, edge distortion is actively relaxed, and the final lens has the advantages of being large in field angle, low in cost and good in image quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical design, in particular to a 178° ultra-wide-angle optical imaging system. BACKGROUND

[0002] With the rapid development of smart cities and security monitoring networks, the front-end equipment has increasingly urgent requirements for "single lens, large field of view, and low cost". Especially in the face of "thousands of roads" large-scale deployment, how to balance the field of view, image quality, and cost has become a core problem in technical research and development. At present, the common ultra-wide-angle optical imaging systems on the market mostly use aspherical plastic lenses or multi-piece (more than nine pieces) glass lens structures to achieve a field of view close to or exceeding 180°. However, these designs, although to some extent, can solve the problems of distortion and chromatic aberration, but they have many defects: first, the material cost of aspherical plastic lenses is high, and the processing difficulty is great; second, the structure of multiple lenses not only makes it difficult to guarantee the processing precision, but also increases the weight and volume of the system, affecting the stability and durability of the system, especially in scenes with large temperature changes, which is prone to problems such as focal length drift and aberration change; in addition, due to the complexity of the production process, the consistency is poor in batch production, further increasing the difficulty of quality control and large-scale deployment.

[0003] Therefore, there is an urgent need for a new optical imaging scheme that can maintain an ultra-wide field of view (178°) while reducing costs, simplifying the structure, and ensuring high stability of image quality. Based on this demand, the present application proposes an innovative solution that, through clever design, uses a structure of 8 spherical glass lenses, effectively controlling costs while achieving good optical performance. This design not only guarantees the field of view, but also fully considers aberration correction and reduces distortion by reasonably configuring the lens arrangement, improving the overall image quality. In addition, the total length of the system is significantly optimized, making the optical imaging system more compact and easy to integrate, providing an ideal front-end acquisition solution for security monitoring systems. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide an ultra-wide-angle vehicle-mounted optical imaging system scheme with low manufacturing cost and high cost performance. The 178° ultra-wide-angle optical imaging system provided by the present application selects a field of view of 102° according to actual application needs. The lenses of the system are all designed using spherical lenses, reducing the processing difficulty and manufacturing cost. All types of aberrations are corrected during lens design, and the final lens has the advantages of large field of view, low cost, good image quality, and miniaturization.

[0005] In order to achieve the above purpose, the present application realizes the following technical scheme.

[0006] The application provides a 178-degree super-wide-angle optical imaging system, comprising an optical lens and a photoelectric conversion device, wherein the lens part is characterized in that: comprising a first negative lens 1, a second negative lens 2, a third negative lens 3, a first positive lens 4, a second positive lens 5, a third positive lens 6, a fourth negative lens 7 and a fifth negative lens 8 arranged coaxially in sequence along the light incident direction; the material of the first negative lens 1 is HLAF3_CDGM, the object side is convex, the image side is concave, the clear aperture is 131mm<132mm, the thickness is 12.5mm<13.5mm, the first surface curvature is 112<123, the second surface curvature is 27<28, the first surface refers to the optical surface of the lens that is first contacted when the light enters the lens, and the second surface refers to the optical surface of the lens that is contacted when the light exits after propagating through the lens; the material of the second negative lens 2 is HK9L_CDGM, the object side is concave, the image side is concave, the clear aperture is 55mm<56mm, the thickness is 5mm<6mm, the first surface curvature is -198<-197, and the second surface curvature is 28<29; the material of the third negative lens 3 is HZF6_CDGM, the object side is convex, the image side is concave, the clear aperture is 41mm<42mm, the thickness is 9.5mm<10.5mm, the first surface curvature is 82<83, and the second surface curvature is 25<26; the material of the first positive lens 4 is HLAF4_CDGM, the object side is convex, the image side is convex, the clear aperture is 36mm<37mm, the thickness is 12.5mm<13.5mm, the first surface curvature is 25<26, and the second surface curvature is -117<-116; the material of the second positive lens 5 is HQK3L_CDGM, the object side is convex, the image side is concave, the clear aperture is 29.5mm<30.5mm, the thickness is 9.5mm<10.5mm, the first surface curvature is 22<23, and the second surface curvature is 144<145; the material of the third positive lens 6 is HZK9A_CDGM, the object side is convex, the image side is convex, the clear aperture is 6.5mm<7.5mm, the thickness is 9.5mm<10.5mm, the first surface curvature is 41<42, and the second surface curvature is -10<-9; the material of the fourth negative lens 7 is HZF6_CDGM, the object side is concave, the image side is convex, the clear aperture is 11.5mm<12.5mm, the thickness is 4.5mm<5.5mm, the first surface curvature is -10<-9, and the second surface curvature is -46.5<45.5; the material of the fifth negative lens 8 is HQK3L_CDGM, the object side is concave, the image side is concave, the clear aperture is 16mm<17mm, the thickness is 15.5mm<16.5mm, the first surface curvature is -46.5<-45.5, and the second surface curvature is 150<151; and the aforementioned eight kinds of optical glasses realize good chromatic aberration and aberration correction effect through material matching.

[0007] Optionally, the first negative lens has an aperture of 131.60 mm, a thickness of 13 mm, a first surface curvature of 112.23, and a second surface curvature of 27.67; the second negative lens has an aperture of 55.33 mm, a thickness of 5.2 mm, a first surface curvature of -197.85, and a second surface curvature of 28.29; the third negative lens has an aperture of 41.07 mm, a thickness of 10 mm, a first surface curvature of 82.02, and a second surface curvature of 25.27; the first positive lens has an aperture of 36.88 mm, a thickness of 16 mm, a first surface curvature of 25.27, and a second surface curvature of -116.19; the second positive lens has an aperture of 29.77 mm, a thickness of 10 mm, a first surface curvature of 22.54, and a second surface curvature of 144.77; the third positive lens has an aperture of 7.04 mm, a thickness of 10 mm, a first surface curvature of 41.06, and a second surface curvature of -9.66; the fourth negative lens has an aperture of 12.04 mm, a thickness of 5 mm, a first surface curvature of -9.66, and a second surface curvature of -45.93; and the fifth negative lens has an aperture of 16.72 mm, a thickness of 16 mm, a first surface curvature of -45.93, and a second surface curvature of 150.57.

[0008] Optionally, the third negative lens and the first positive lens form a cemented lens, and the third positive lens, the fourth negative lens, and the fifth negative lens form a cemented lens.

[0009] Optionally, the distance between the center of the light exit surface of the fifth negative lens and the image surface is 1.0 mm.

[0010] Optionally, the optical size of the 178° super-wide-angle optical imaging system lens is φ112.2*151.87 mm.

[0011] Optionally, the working wavelength range of the 178° super-wide-angle optical imaging system lens is 400 nm-700 nm.

[0012] Optionally, the full field of view angle of the 178° super-wide-angle optical imaging system lens is 178°.

[0013] Optionally, the optical system focal length of the 178° super-wide-angle optical imaging system lens is 13.66 mm, and the F number is 5.46.

[0014] From the above technical solutions, it can be seen that the embodiments of the present application have the following advantages: 1. The 178° super-wide-angle optical imaging system has a lens composed of eight spherical lenses, and has low cost. 2. The spherical super-wide-angle optical imaging system, F number 5.46, strong lens light collecting capacity, ensures clear imaging of the surrounding environment, full field of view 178°, large field of view angle can ensure perfect capture of the surrounding environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The optical system structure diagram of the 178° super-wide-angle optical imaging system of the present application; Figure 2 The point diagram of the 178° super-wide-angle optical imaging system of the present application; Figure 3 The optical modulation transfer function of the 178° super-wide-angle optical imaging system of the present application; Reference signs: 1-first negative lens; 2-second negative lens; 3-third negative lens; 4-first positive lens; 5-second positive lens; STO-stop surface; 6-third positive lens; 7-fourth negative lens; 8-fifth negative lens; IMA-image surface. DETAILED DESCRIPTION

[0016] In order to make the personnel in the art better understand the present application scheme, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0017] Please refer to Figure 1As shown in the structural diagram of the optical system of the present application, the 178° super-wide-angle optical imaging system has a lens part comprising eight lenses arranged in the form of negative-negative-negative-positive-positive-positive-negative-negative, and the eight lenses comprise, in sequence along the light incident direction, a first negative lens 1, a second negative lens 2, a third negative lens 3, a first positive lens 4, a second positive lens 5, a third positive lens 6, a fourth negative lens 7, and a fifth negative lens 8 arranged coaxially. The first negative lens 1 is made of HLAF3_CDGM, has a convex object side and a concave image side, a clear aperture of 131mm<132mm, a thickness of 12.5mm<13.5mm, a first surface curvature of 112<123, and a second surface curvature of 27<28. The second negative lens 2 is made of HK9L_CDGM, has a concave object side and a concave image side, a clear aperture of 55mm<56mm, a thickness of 5mm<6mm, a first surface curvature of -198<-197, and a second surface curvature of 28<29. The third negative lens 3 is made of HZF6_CDGM, has a convex object side and a concave image side, a clear aperture of 41mm<42mm, a thickness of 9.5mm<10.5mm, a first surface curvature of 82<83, and a second surface curvature of 25<26. The first positive lens 4 is made of HLAF4_CDGM, has a convex object side and a convex image side, a clear aperture of 36mm<37mm, a thickness of 12.5mm<13.5mm, a first surface curvature of 25, and a second surface curvature of -117<-116. The second positive lens 5 is made of HQK3L_CDGM, has a convex object side and a concave image side, a clear aperture of 29.5mm<30.5mm, a thickness of 9.5mm<10.5mm, a first surface curvature of 22, and a second surface curvature of 144<145. The third positive lens 6 is made of HZK9A_CDGM, has a convex object side and a convex image side, a clear aperture of 6.5mm<7.5mm, a thickness of 9.5mm<10.5mm, a first surface curvature of 41, and a second surface curvature of -10<-9. The fourth negative lens 7 is made of HZF6_CDGM, has a concave object side and a convex image side, a clear aperture of 11.5mm<12.5mm, a thickness of 4.5mm<5.5mm, a first surface curvature of -10<-9, and a second surface curvature of -46.5<45.5. The fifth negative lens 8 is made of HQK3L_CDGM, has a concave object side and a concave image side, a clear aperture of 16mm<17mm, a thickness of 15.5mm<16.5mm, a first surface curvature of -46.5<-45.5, and a second surface curvature of 150<151.

[0018] In one of the embodiments, the first negative lens has an aperture of 131.60 mm, a thickness of 13 mm, a first surface curvature of 112.23, and a second surface curvature of 27.67; the second negative lens has an aperture of 55.33 mm, a thickness of 5.2 mm, a first surface curvature of -197.85, and a second surface curvature of 28.29; the third negative lens has an aperture of 41.07 mm, a thickness of 10 mm, a first surface curvature of 82.02, and a second surface curvature of 25.27; the first positive lens has an aperture of 36.88 mm, a thickness of 16 mm, a first surface curvature of 25.27, and a second surface curvature of -116.19; the second positive lens has an aperture of 29.77 mm, a thickness of 10 mm, a first surface curvature of 22.54, and a second surface curvature of 144.77; the third positive lens has an aperture of 7.04 mm, a thickness of 10 mm, a first surface curvature of 41.06, and a second surface curvature of -9.66; and the fourth negative lens has an aperture of 12.04 mm, a thickness of 5 mm, a first surface curvature of -9.66, and a second surface curvature of -45.93. In this way, the optical system has a focal length of 13.66 mm, an F number of 5.46, a full field of view of 178°, and an overall size of φ112.2*151.87 mm, and has the advantages of a large field of view, low cost, and good image quality.

[0019] In one of the embodiments, the third negative lens 3 and the first positive lens 4 form a cemented lens, and the third positive lens 6, the fourth negative lens 7, and the fifth negative lens 8 form a cemented lens, and the optical material of the cemented lens is matched to ensure that the chromatic aberration of the optical system is well corrected.

[0020] In one of the embodiments, the 178° super-wide-angle optical imaging system has a field of view of 178°, and has the advantage of a super-large field of view.

[0021] Referring to Figure 2 The spot diagram of the optical system of the present application shows that the spot RMS within the full field of view is less than 7.7 μm, which indicates that the aberration of the optical system is well corrected as a whole, and the aberration correction effect of the area close to the central field of view, which has a greater viewing weight, is better than that of the edge field of view.

[0022] Referring to Figure 3 The optical modulation transfer function of the optical system of the present application shows that the optical modulation transfer function of most of the fields of view is higher than 0.2 within a spatial frequency range of 80 cycles / mm, which indicates that the optical system has good imaging quality.

[0023] The following table shows the lens data of the 178° super wide-angle optical imaging system. Table 1 shows the surface type and surface parameters of each lens in the optical system.

[0024] Table 1 Surface number Surface type Radius of curvature R Thickness D Refractive index nd / Dispersion coefficient vd OBJ Sphere Infinity Infinity S1 Sphere 112.2251 13.0000 1.74400 / 44.9 S2 Sphere 27.6667 29.5313 S3 Sphere -197.8457 5.2000 1.51680 / 64.2 S4 Sphere 28.2947 25.1386 S5 Sphere 82.0224 10.0000 1.75521 / 27.5 S6 Sphere 25.2687 16.0000 1.74950 / 35.0 S7 Sphere -116.1873 0.1000 S8 Sphere 22.5408 10.0000 1.48749 / 70.4 S9 Sphere 144.7719 10.6421 STO Sphere Infinity 0.2120 S11 Sphere 41.0570 10.0000 1.62041 / 60.4 S12 Sphere -9.6556 5.0000 1.75521 / 27.5 S13 Sphere -45.9349 16.0000 1.48749 / 70.4 S14 Sphere 150.5710 1.0497 S15 Sphere Infinity 8.0000 IMA Sphere Infinity 0.0000 The 178° super wide-angle optical imaging system has a focal length of 13.66 mm, an F number of 5.46, a field of view angle of 178°, and an optical size of φ112.2*151.87 mm. The lens is mainly configured in the front end of a video monitoring system to monitor an area with a single imaging unit, and is used to collect panoramic images of entrance and exit, squares, perimeters, and large space scenes. In the design process of the lens, cost factors are fully considered, a scheme of using all spherical lenses is adopted, various aberrations are corrected and balanced, and the lens has the advantages of large field of view angle, low cost, good image quality, and the like.

[0025] The specific embodiments of the application described above do not constitute a limitation on the protection scope of the application. Any various other corresponding changes and modifications made according to the technical concept of the application shall be included in the protection scope of the claims of the application.

Claims

1. A 178° ultra-wide-angle optical imaging system, comprising an optical lens and a photoelectric conversion device, wherein the lens portion is characterized by comprising a first negative lens, a second negative lens, a third negative lens, a first positive lens, a second positive lens, a third positive lens, a fourth negative lens, and a fifth negative lens arranged coaxially along the incident direction of light. The first negative lens is made of HLAF3_CDGM, with a convex object side and a concave image side. The aperture diameter is 131mm < 132mm, the thickness is 12.5mm < 13.5mm, the curvature of the first surface is 112 < 123, and the curvature of the second surface is 27 < 28. The material of the second negative lens is HK9L_CDGM, the object side is concave, the image side is concave, 55mm < light aperture < 56mm, 5mm < thickness < 6mm, -198 < first surface curvature < -197, 28 < second surface curvature < 29; The material of the third negative lens is HZF6_CDGM, the object side is convex, the image side is concave, 41mm < aperture < 42mm, 9.5mm < thickness < 10.5mm, 82 < first surface curvature < 83, 25 < second surface curvature < 26; The first positive lens is made of HLAF4_CDGM, with a convex object side and a convex image side. The aperture diameter is 36mm < 37mm, the thickness is 12.5mm < 13.5mm, the curvature of the first surface is 25 < 26, and the curvature of the second surface is -117 < -116. The material of the second positive lens is HQK3L_CDGM, the object side is convex, the image side is concave, 29.5mm < aperture diameter < 30.5mm, 9.5mm < thickness < 10.5mm, 22 < first surface curvature < 23, 144 < second surface curvature < 145; The material of the third positive lens is HZK9A_CDGM, the object side is convex, the image side is convex, 6.5mm < aperture diameter < 7.5mm, 9.5mm < thickness < 10.5mm, 41 < first surface curvature < 42, -10 < second surface curvature < -9; The fourth negative lens is made of HZF6_CDGM, with a concave object side and a convex image side. Its dimensions are: 11.5mm < aperture diameter < 12.5mm, 4.5mm < thickness < 5.5mm, -10 < first surface curvature < -9, -46.5 < second surface curvature < 45.

5. The fifth negative lens is made of HQK3L_CDGM material, with a concave object side and a concave image side. The aperture diameter is 16mm < 17mm, the thickness is 15.5mm < 16.5mm, the curvature of the first surface is -46.5 < -45.5, and the curvature of the second surface is 150 < 151.

2. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized by: The first negative lens has a light-transmitting aperture of 131.60 mm, a thickness of 13 mm, a first surface curvature of 112.23, and a second surface curvature of 27.

67. The second negative lens has a light-transmitting aperture of 55.33 mm, a thickness of 5.2 mm, a first surface curvature of -197.85, and a second surface curvature of 28.

29. The third negative lens has a light-transmitting aperture of 41.07 mm, a thickness of 10 mm, a first surface curvature of 82.02, and a second surface curvature of 25.

27. The first positive lens has a light-transmitting aperture of 36.88 mm, a thickness of 16 mm, a first surface curvature of 25.27, and a second surface curvature of -116.

19. The second positive lens has a light-transmitting aperture of 29.77 mm, a thickness of 10 mm, a first surface curvature of 22.54, and a second surface curvature of 144.

77. The third positive lens has a light-transmitting aperture of 7.04 mm, a thickness of 10 mm, a first surface curvature of 41.06, and a second surface curvature of -9.

66. The fourth negative lens has a light-transmitting aperture of 12.04 mm, a thickness of 5 mm, a first surface curvature of -9.66, and a second surface curvature of -45.

93. The fifth negative lens has a light-transmitting aperture of 16.72 mm, a thickness of 16 mm, a first surface curvature of -45.93, and a second surface curvature of 150.

57.

3. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized in that: the third negative lens and the first positive lens form a cemented lens, and the third positive lens, the fourth negative lens and the fifth negative lens form a cemented lens.

4. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized in that the distance between the center of the light emitting surface of the fifth negative lens and the image plane is 1.0 mm.

5. The ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized in that: the optical dimensions of the lens of the 178° ultra-wide-angle optical imaging system are φ112.2×151.87mm.

6. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized in that: the working wavelength range of the lens of the 178° ultra-wide-angle optical imaging system is 400nm~700nm.

7. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens portion is characterized in that: the full field of view of the lens of the 178° ultra-wide-angle optical imaging system is 178°.

8. The 178° ultra-wide-angle optical imaging system as described in claim 1, wherein the lens is characterized in that: the optical system focal length of the 178° ultra-wide-angle optical imaging system lens is 13.66mm and the F number is 5.

46.

9. A 178° ultra-wide-angle optical imaging system, wherein the photoelectric conversion device can be a CCD or a CMOS.

Images