A high-definition lawnmower image acquisition optical system and camera device with day and night confocal focus

Abstract

This invention relates to the field of optical imaging technology, and in particular to a high-definition lawnmower image acquisition optical system and camera device with day and night confocal focusing. The optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged along the object side to the image side. By rationally using cemented glass lenses and limiting the optical power of each lens, the spherical aberration, coma, astigmatism, field curvature, positional chromatic aberration, and magnification chromatic aberration of the entire lens system are effectively reduced. The design uses low-dispersion materials, which optimizes the purple fringing effect at the edges of objects, better restoring the true scene. The small distortion also gives the entire optical system a thermal compensation effect, with stable thermal drift at high temperatures of 85°C and low temperatures of -40°C, ensuring use in extreme external environments. The aperture reaches F2.0, and it has built-in infrared confocal focusing, which meets the needs of use in low-light conditions at night.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, specifically to a high-definition lawnmower image acquisition optical system and camera device with day and night confocal focus. Background Technology

[0002] Nowadays, traditional manual lawnmowers are gradually being replaced by new intelligent lawnmowers. Intelligent lawnmowers eliminate the need for direct human control and operation, saving labor costs and offering advantages such as higher efficiency and lower power consumption. Existing intelligent lawnmowers generally mow within a designated area through random collisions or by using GPS positioning to mow along pre-set routes. However, neither of these methods can accurately reflect the actual lawn environment, leading to repeated mowing, low efficiency, and missed mowing spots due to poor route planning. To achieve mowing based on the actual lawn environment, it's best to equip the lawnmower with an image acquisition optical system and camera equipment. By capturing the surrounding environment, the chip can better assist in identification and analysis, thus planning a reasonable mowing route and preventing missed or repeated mowing. However, existing lawnmower image acquisition optical systems and camera equipment generally suffer from problems such as insufficient holographic height (unable to match large target surfaces), significant distortion (causing edge image distortion), unclear images at night or in low light conditions, poor thermal drift stability under extreme environmental conditions, and severe purple fringing at the edges. Summary of the Invention

[0003] To address the problems existing in the prior art, the purpose of this invention is to provide a high-definition lawnmower image acquisition optical system and camera device with day and night confocal focus. This high-definition lawnmower image acquisition optical system and camera device with day and night confocal focus combines the advantages of day and night confocal focus, 4K high definition, large target area, low distortion, purple fringing optimization, and thermal drift stability.

[0004] The above-mentioned technical objective of this invention is achieved through the following technical solution: a high-definition lawnmower image acquisition optical system with day and night confocal focusing, comprising a first lens, a second lens, a third lens, a fourth lens, a first cemented lens group, a second cemented lens group, a third cemented lens group, and an eleventh lens arranged along the direction from the object side to the image side; the first lens is a meniscus glass lens with positive optical power; the second lens is a meniscus glass lens with negative optical power; the third lens is a meniscus glass lens with negative optical power; the fourth lens is a concave-convex glass lens with positive optical power; the first cemented lens group is a group of glass lenses with positive optical power; the second cemented lens group is a group of glass lenses with negative optical power; the third cemented lens group is a group of glass lenses with positive optical power; and the eleventh lens is a biconcave glass lens with negative optical power.

[0005] In some embodiments, the first cemented lens group includes a fifth lens and a sixth lens, wherein the fifth lens is a meniscus glass lens with positive optical power, and the sixth lens is a biconvex glass lens with positive optical power; the second cemented lens group includes a seventh lens and an eighth lens, wherein the seventh lens is a biconcave glass lens with negative optical power, and the eighth lens is a biconvex glass lens with positive optical power; the third cemented lens group includes a ninth lens and a tenth lens, wherein the ninth lens is a meniscus glass lens with positive optical power, and the tenth lens is a biconvex glass lens with negative optical power.

[0006] In some embodiments, the first lens has a convex surface facing the object side and a slightly concave surface facing the image side; the second lens has a convex surface facing the object side and a concave surface facing the image side; the third lens has a convex surface facing the object side and a concave surface facing the image side; the fourth lens has a slightly convex surface facing the object side and a slightly concave surface facing the image side; the fifth lens has a convex surface facing the object side and a concave surface facing the image side; the sixth lens has a convex surface facing the object side and a convex surface facing the image side; the seventh lens has a large concave surface facing the object side and a small concave surface facing the image side; the eighth lens has a small convex surface facing the object side and a large convex surface facing the image side; the ninth lens has a convex surface facing the object side and a concave surface facing the image side; the tenth lens has a convex surface facing the object side and a slightly convex surface facing the image side; and the eleventh lens has a slightly concave surface facing the object side and a concave surface facing the image side.

[0007] In some embodiments, the refractive index of both the third lens and the eleventh lens is equal to 1.50, and the Abbe coefficient is greater than 78 and less than 85.

[0008] In some embodiments, the refractive index of both the eighth and tenth lenses is 1.59, and the Abbe coefficient is greater than 65 and less than 71.

[0009] In some embodiments, the absolute values ​​of the effective focal lengths of the second lens and the seventh lens are both greater than 6 and less than 11.

[0010] In some embodiments, the relative aperture of the optical system is F2.0.

[0011] In some embodiments, the effective focal length f of the optical system satisfies the following condition: 4.9mm ≤ f ≤ 5.6mm.

[0012] A camera device that employs the day-night confocal high-definition lawnmower image acquisition optical system described in any of the above embodiments.

[0013] In summary, the present invention has the following beneficial effects:

[0014] This high-definition lawnmower image acquisition optical system and camera equipment with day and night confocal focusing effectively reduces spherical aberration, coma, astigmatism, field curvature, positional chromatic aberration, and magnification chromatic aberration of the entire lens system through glass-ceramic lenses, improving the final image quality and chromatic aberration correction to meet 4K high-definition applications. The design uses low-dispersion lens materials to optimize the purple fringing effect at the edges of objects, better restoring the real scene. At the same time, the entire optical system has a thermal compensation effect, with stable thermal drift at high temperatures of 85℃ and low temperatures of -40℃, ensuring that the resolution remains unchanged when the external environment changes between high and low temperatures. The aperture reaches F2.0, which can absorb more light, and it has a built-in infrared confocal function, which meets the needs of automatic lawnmowers to use in dark environments at night. The focal length is as long as 5.16mm, and the full image height can reach 9.43mm, which can capture objects at a greater distance. Matched with a 1 / 1.9” large target surface chip, the optical distortion is small, and the overall distortion is controlled within -7%, which will not cause distortion at the edge of the image. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a lens according to an embodiment of the present invention;

[0016] Figure 2 This is an analytical plot of 125 lp / mm MTF at 20°C according to an embodiment of the present invention;

[0017] Figure 3 This is a defocusing curve at 20°C with a focal length of 125 lp / mm, according to an embodiment of the present invention.

[0018] Figure 4 This is a defocusing curve at 85°C and 125 lp / mm, according to an embodiment of the present invention.

[0019] Figure 5 This is a defocusing curve at -40℃ with 125 lp / mm, according to an embodiment of the present invention.

[0020] Figure 6 This is a field curvature diagram of an embodiment of the present invention;

[0021] Figure 7 This is an optical distortion diagram according to an embodiment of the present invention.

[0022] In the diagram: E1, first lens; E2, second lens; E3, third lens; E4, fourth lens; E5, fifth lens; E6, sixth lens; E7, seventh lens; E8, eighth lens; E9, ninth lens; E10, tenth lens; E11, eleventh lens. Detailed Implementation

[0023] The following will provide an embodiment of the optical system of the present invention. It should be noted that the data listed in the table below are preferred data for the present invention and are not intended to limit the invention. Any person skilled in the art, after referring to the present invention, can make appropriate changes to the parameters or settings, and such changes should still fall within the scope of the present invention.

[0024] The parameters of the lens group are listed in Table 1:

[0025]

[0026]

[0027] Table 1

[0028] Aspherical coefficients are shown in Table 2:

[0029] SURFACE:19 K＝1130.993558723 E4＝-0.002203107542281 E6＝0.00002176967313163 R1＝152.700146235346 SURFACE:20 K＝-4.634957019301 E4＝-0.0007240685673266 E6＝0.00003857252319936 R2＝16.6075303856547

[0030] Table 2

[0031] The aspherical coefficients satisfy the following equation:

[0032]

[0033] Where z is the aspherical sagitta, c is the paraxial curvature of the aspherical surface, y is the lens aperture, k is the conic coefficient, a4 is the fourth-order aspherical coefficient, and a6 is the sixth-order aspherical coefficient.

[0034] Specifically, the R-values ​​and thicknesses of each lens surface in this embodiment are shown in Table 1, and the aspherical parameters are shown in Table 2.

[0035] The optical system provided in Table 1 has an effective focal length of 5.16mm, a total image height of 9.43mm, a light-transmitting aperture of F2.0, and a field of view of 89 degrees (2w). In Table 1, mirror numbers 1 and 2 represent the two mirrors of the first lens along the direction of light incidence, mirror numbers 3 and 4 represent the two mirrors of the second lens along the direction of light incidence, mirror numbers 5 and 6 represent the two mirrors of the third lens along the direction of light incidence, mirror numbers 7 and 8 represent the two mirrors of the fourth lens along the direction of light incidence, mirror number 10 represents the object-facing mirror of the fifth lens, mirror number 11 represents the cemented surface of the fifth and sixth lenses, and mirror number 12... The mirror number 13 represents the image-side surface of the sixth lens, the mirror number 14 represents the object-side surface of the seventh lens, the mirror number 15 represents the image-side surface of the eighth lens, the mirror number 16 represents the object-side surface of the ninth lens, the mirror number 17 represents the object-side surface of the ninth and tenth lenses, the mirror number 18 represents the image-side surface of the tenth lens, and the mirror numbers 19 and 20 represent the two mirrors of the eleventh lens along the direction of ray incidence, respectively.

[0036] like Figure 1 As shown in the embodiment of the present invention, a high-definition lawnmower image acquisition optical system with day and night confocal focusing includes a first lens, a second lens, a third lens, a fourth lens, a first cemented lens group, a second cemented lens group, a third cemented lens group, and an eleventh lens arranged along the direction from the object side to the image side; the first lens is a meniscus glass lens with positive optical power; the second lens is a meniscus glass lens with negative optical power; the third lens is a meniscus glass lens with negative optical power; the fourth lens is a concave-convex glass lens with positive optical power; the first cemented lens group is a group of glass lenses with positive optical power; the second cemented lens group is a group of glass lenses with negative optical power; the third cemented lens group is a group of glass lenses with positive optical power; and the eleventh lens is a biconcave glass lens with negative optical power.

[0037] The first cemented lens group includes a fifth lens and a sixth lens, wherein the fifth lens is a meniscus glass lens with positive optical power, and the sixth lens is a biconvex glass lens with positive optical power; the second cemented lens group includes a seventh lens and an eighth lens, wherein the seventh lens is a biconcave glass lens with negative optical power, and the eighth lens is a biconvex glass lens with positive optical power; the third cemented lens group includes a ninth lens and a tenth lens, wherein the ninth lens is a meniscus glass lens with positive optical power, and the tenth lens is a biconvex glass lens with negative optical power.

[0038] The first lens has a convex surface facing the object side and a slightly concave surface facing the image side; the second lens has a convex surface facing the object side and a concave surface facing the image side; the third lens has a convex surface facing the object side and a concave surface facing the image side; the fourth lens has a slightly convex surface facing the object side and a slightly concave surface facing the image side; the fifth lens has a convex surface facing the object side and a concave surface facing the image side; the sixth lens has a convex surface facing the object side and a convex surface facing the image side; the seventh lens has a large concave surface facing the object side and a small concave surface facing the image side; the eighth lens has a small convex surface facing the object side and a large convex surface facing the image side; the ninth lens has a convex surface facing the object side and a concave surface facing the image side; the tenth lens has a convex surface facing the object side and a slightly convex surface facing the image side; and the eleventh lens has a slightly concave surface facing the object side and a concave surface facing the image side.

[0039] The refractive index of both the third and eleventh lenses is 1.50, and their Abbe coefficients are both greater than 78 and less than 85.

[0040] The refractive index of both the eighth and tenth lenses is 1.59, and the Abbe coefficients are both greater than 65 and less than 71.

[0041] The absolute values ​​of the effective focal lengths of the second and seventh lenses are both greater than 6 and less than 11.

[0042] The relative aperture of the optical system is F2.0.

[0043] The effective focal length f of the optical system satisfies the following condition: 4.9mm≤f≤5.6mm.

[0044] The camera device described in this embodiment of the invention employs the aforementioned high-definition lawnmower image acquisition optical system with day and night confocal focus.

[0045] All of the above embodiments of the present invention meet the requirements.

[0046] In an embodiment of the present invention, Figure 2 This is a modulation transfer function (MTF) curve for the visible light band, representing the overall resolving power of an optical system. The horizontal axis represents spatial frequency, in cycles per millimeter (mm), and the vertical axis represents the MTF value. The MTF value is used to evaluate the image quality of a lens, ranging from 0 to 1. It is worth noting that the optical transfer function is a relatively accurate, intuitive, and common way to evaluate the image quality of an optical system. The higher and smoother the curve, the better the image quality and the stronger the ability to reproduce the true image. Figure 2It can be seen that in the visible light band, at a spatial frequency of 125 lp / mm, the MTF in the imaging region near the center is >0.6, indicating good imaging quality. Figure 3 The defocus curve shows that the lens has good MTF concentration, making focusing easy. From... Figure 4 and Figure 5 It can be seen that the defocus curves at both high and low temperatures meet the requirements of high resolution, with small changes in focus and stable thermal drift effect; Figure 6 Representing the field curve diagram, by Figure 6 It can be seen that the field curvature value should be controlled between -0.05mm and 0.05mm. The smaller the field curvature value, the better the image quality of the lens. Figure 7 Represents optical distortion diagrams, by Figure 7 It can be seen that the optical distortion is small, with the overall distortion controlled within -7%, and will not cause distortion at the edges of the image.

[0047] Through the above technical solutions, this invention provides a day-and-night confocal high-definition lawnmower image acquisition optical system and camera device. The optical system includes a first lens, a second lens, a third lens, a fourth lens, a first cemented lens group, a second cemented lens group, a third cemented lens group, and an eleventh lens arranged along the object-to-image direction. The surface of the first meniscus lens facing the object is convex. The first to tenth lenses are all spherical glass lenses, while the eleventh lens is an aspherical glass lens. The cemented glass lenses effectively reduce spherical aberration, coma, astigmatism, field curvature, positional chromatic aberration, and magnification chromatic aberration of the entire lens system, improving the final image quality and chromatic aberration correction to meet 4K high-definition applications. The design uses low-dispersion lens materials, optimizing the purple fringing effect at object edges for better reproduction of the real scene. Simultaneously, the entire optical system has a thermal compensation effect, maintaining thermal drift stability at high temperatures of 85 degrees Celsius and low temperatures of -40 degrees Celsius, ensuring consistent resolution under varying external environmental conditions. With an aperture of F2.0, it can absorb more light and has a built-in infrared confocal function, which meets the needs of automatic lawnmowers in low-light environments at night. The focal length is as long as 5.16mm and the full-image height can reach 9.43mm, which can capture distant objects. It is matched with a 1 / 1.9” large target surface chip, with low optical distortion and overall distortion controlled within -7%, so as not to cause distortion at the edge of the image.

[0048] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A high-definition lawnmower image acquisition optical system with day and night confocal focusing, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a first cemented lens group, a second cemented lens group, a third cemented lens group, and an eleventh lens arranged along the direction from the object side to the image side; The first lens is a meniscus glass lens with positive optical power; The second lens is a meniscus glass lens with negative optical power; The third lens is a meniscus glass lens with negative optical power; The fourth lens is a concave-convex glass lens with positive optical power; The first cemented lens group is a group of glass lenses with positive optical power; The second cemented lens group is a group of glass lenses with negative optical power; The third cemented lens group is a group of glass lenses with positive optical power; The eleventh lens is a biconcave glass lens with negative optical power; The first cemented lens group includes a fifth lens and a sixth lens, wherein the fifth lens is a meniscus glass lens with positive optical power, and the sixth lens is a biconvex glass lens with positive optical power. The second cemented lens group includes a seventh lens and an eighth lens, wherein the seventh lens is a biconcave glass lens with negative optical power, and the eighth lens is a biconvex glass lens with positive optical power. The third cemented lens group includes a ninth lens and a tenth lens, wherein the ninth lens is a meniscus glass lens with positive optical power, and the tenth lens is a biconvex glass lens with negative optical power. The optical system has 11 lenses; The first lens has a convex surface facing the object side and a concave surface facing the image side; The second lens has a convex surface facing the object side and a concave surface facing the image side; The third lens has a convex surface facing the object side and a concave surface facing the image side. The fourth lens has a convex surface facing the object side and a concave surface facing the image side. The fifth lens has a convex surface facing the object side and a concave surface facing the image side. The sixth lens has a convex surface on the object side and a convex surface on the image side. The seventh lens has a large concave surface on the object side and a small concave surface on the image side. The eighth lens has a small convex surface on the object side and a large convex surface on the image side. The ninth lens has a convex surface facing the object side and a concave surface facing the image side. The tenth lens has a convex surface on the object side and a convex surface on the image side. The eleventh lens has a concave surface on both the object side and the image side.

2. The high-definition lawnmower image acquisition optical system with day and night confocal focusing as described in claim 1, characterized in that: The refractive index of both the third and eleventh lenses is 1.50, and their Abbe coefficients are both greater than 78 and less than 85.

3. The high-definition lawnmower image acquisition optical system with day and night confocal focusing as described in claim 1, characterized in that: The refractive index of both the eighth and tenth lenses is 1.59, and the Abbe coefficients are both greater than 65 and less than 71.

4. The high-definition lawnmower image acquisition optical system with day and night confocal focusing as described in claim 1, characterized in that: The absolute values ​​of the effective focal lengths of the second and seventh lenses are both greater than 6 mm and less than 11 mm.

5. A high-definition lawnmower image acquisition optical system with day and night confocal focusing according to any one of claims 1-4, characterized in that: The relative aperture of the optical system is F2.

0.

6. A high-definition lawnmower image acquisition optical system with day and night confocal focusing according to any one of claims 1-4, characterized in that: The effective focal length f of the optical system satisfies the following condition: 4.9mm ≤ f ≤ 5.6mm.

7. A camera device, characterized in that: Including the high-definition lawnmower image acquisition optical system with day and night confocal focus as described in any one of claims 1 to 4.

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