Long-wave infrared uncooled fisheye lens with 180-degree field angle

Abstract

The utility model relates to the technical field of optics, in particular to a long-wave infrared uncooled 180-degree field angle fisheye lens, which comprises a first lens. A second lens is arranged on one side of the first lens, a third lens is arranged on one side of the second lens, and a fourth lens is arranged on one side of the third lens. According to the utility model, by using the semi-symmetric optical structure, good imaging performance in a 180-degree full view field is realized, a good application effect is achieved, and the problems that the view field angle of a lens of a device in the prior art is small, and 360-degree peripheral patterns can be formed only by splicing a plurality of cameras are solved. Therefore, the problems that the cost is high, the installation and debugging are time-consuming, and the later image algorithm is more complicated are caused. The objective of the utility model is to solve the problems in the prior art that a lens covering a 180-degree field of view is urgently needed, the 360-degree field of view can be realized by splicing only two cameras, at the same time, the resolution of an infrared camera is upgraded to 1280 * 1024 pixels, the image surface size is larger, and the realization difficulty is further improved.

Description

Technical Field

[0001] This utility model belongs to the field of optical technology, specifically a long-wave infrared uncooled 180° field of view fisheye lens. Background Technology

[0002] In a vehicle driving system, a certain number of cameras need to be placed around the vehicle to transmit information about the surrounding environment, which is then used by the driving system or the driver to make judgments.

[0003] Existing technologies often require lenses with small fields of view, necessitating the stitching of multiple cameras to create a 360° peripheral pattern. This results in high costs, time-consuming installation and debugging, and more complex post-processing image algorithms. Therefore, there is an urgent need for a lens covering a 180° field of view, requiring only two cameras to achieve a 360° field of view. However, the resolution of infrared cameras has been upgraded to 1280x1024 pixels, resulting in a larger image size and further increasing the difficulty of implementation. Utility Model Content

[0004] To overcome the limitations of existing technologies where lenses have small field of view, multiple cameras are often required to stitch together a 360° peripheral pattern. This results in high costs, longer installation and debugging times, and more complex post-processing image algorithms. Therefore, there is an urgent need for a lens that covers a 180° field of view, requiring only two cameras to stitch together to achieve a 360° field of view. Meanwhile, infrared camera resolution has been upgraded to 1280x1024 pixels, with a larger image size, further increasing the difficulty of implementation. Therefore, a long-wave infrared uncooled 180° field of view fisheye lens is proposed.

[0005] The technical solution of this utility model is as follows: a long-wave infrared uncooled 180° field-of-view fisheye lens, comprising a first lens; a second lens disposed on one side of the first lens, a third lens disposed on one side of the second lens, and a fourth lens disposed on one side of the third lens; the first lens has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the second lens has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the third lens has positive optical power and is a meniscus glass positive lens with its concave surface facing the object; the fourth lens has positive optical power and is a biconvex glass positive lens; following the fourth lens is an uncooled detector, which includes a protective window and an imaging focal plane.

[0006] Furthermore, the first lens is a negative lens, made of germanium single crystal, with one side of the first lens being a first surface and the other side being a second surface, which is an aspherical surface.

[0007] Furthermore, the second lens is a negative lens made of germanium single crystal. One side of the second lens is a third surface, and the other side of the second lens is a fourth surface, which is an aspherical surface.

[0008] Furthermore, the third lens is a positive lens made of IRG206 glass, with a fifth surface on one side and a sixth surface on the other side. The fifth surface is aspherical.

[0009] Furthermore, the fourth lens is a positive lens made of IRG206 glass. One side of the fourth lens is the seventh surface, and the other side is the eighth surface, which is an aspherical surface.

[0010] Furthermore, the uncooled detector includes a protective window made of germanium single crystal.

[0011] Furthermore, the imaging focal plane has a resolution of 1280x1024 and a pixel size of 12μmx12μm.

[0012] The beneficial effects of this invention are as follows: This optical system is specifically designed for long-wavelength uncooled detectors with a resolution of 1280x1024 and a pixel size of 12 micrometers, meeting the requirements for high sensitivity and high precision detection. The system has a total length of 67.8mm and a maximum aperture of 46mm, with a compact and sophisticated overall structure. Particularly noteworthy is its 180° ultra-wide field of view, enabling comprehensive coverage of a wide range of scenes with excellent imaging quality, clear image details, and well-controlled edge distortion. From a design and manufacturing perspective, the system's structural length meets the requirements of the application scenario, effectively saving space; the smaller lens diameter reduces costs and manufacturing difficulty; and the reasonable tolerance settings ensure precise fit of all components, making assembly and adjustment simple and easy. These advantages enable large-scale mass production, improving production efficiency while ensuring product quality stability and consistency, providing a reliable guarantee for market applications. Attached Figure Description

[0013] Figure 1 The diagram shown is a three-dimensional structural schematic of this utility model.

[0014] The labels in the attached diagram are as follows: 110, first lens; 120, second lens; 130, third lens; 140, fourth lens; 150, uncooled detector; 152, protective window; 154, imaging focal plane; 1, first surface; 2, second surface; 3, third surface; 4, fourth surface; 5, fifth surface; 6, sixth surface; 7, seventh surface; 8, eighth surface. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Please see Figure 1 This utility model provides an embodiment: a long-wave infrared uncooled 180° field-of-view fisheye lens, including a first lens 110; a second lens 120 is disposed on one side of the first lens 110, a third lens 130 is disposed on one side of the second lens 120, and a fourth lens 140 is disposed on one side of the third lens 130; the first lens 110 has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the second lens 120 has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the third lens 130 has positive optical power and is a meniscus glass positive lens with its concave surface facing the object; the fourth lens 140 has positive optical power and is a biconvex glass positive lens; after the fourth lens 140 is an uncooled detector 150, which includes a protective window 152 and an imaging focal plane 154.

[0017] When using,

[0018] surface radius of curvature Thickness (gap) Material caliber 1 34.96 5.7 Ge 46 2 24.603 12.86 31.6 3 16.695 4 Ge 21 4 11.838 5.16 14.6 5 -54.853 5.5 IRG206 12.3 6 -27.014 10.71 21 7 68.61 8.5 IRG206 37 8 -42.751 13.38 37 Protect window Infinity 1 Ge Image Infinity 1

[0019] The aspherical surfaces mentioned in the four lenses above are all even-order aspherical surfaces, and their expressions are as follows:

[0020] Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a position of height r, c represents the vertex curvature of the surface, k is the conic coefficient, and α2, α3, α4, α5, and α6 are higher-order aspherical coefficients;

[0021] Table 2 shows the aspheric coefficients of surfaces 1, 3, and 6:

[0022] Table 2

[0023]

[0024] Please see Figure 1 In this embodiment, the first lens 110 is a negative lens made of germanium single crystal. One side of the first lens 110 is a first surface 1, and the other side of the first lens 110 is a second surface 2. The second surface 2 is aspherical, which reduces light energy loss, effectively corrects aberrations, and improves imaging clarity.

[0025] Please see Figure 1 In this embodiment, the second lens 120 is a negative lens made of germanium single crystal. One side of the second lens 120 is the third surface 3, and the other side is the fourth surface 4. The fourth surface 4 is an aspherical surface. The aspherical surface compensates for specific aberrations, improves edge imaging, and expands the imaging range.

[0026] Please see Figure 1In this embodiment, the third lens 130 is a positive lens made of IRG206 glass. One side of the third lens 130 is the fifth surface 5, and the other side is the sixth surface 6. The fifth surface 5 is an aspherical surface. The positive lens balances the optical power, and the aspherical surface enables the system to be lightweight.

[0027] Please see Figure 1 In this embodiment, the fourth lens 140 is a positive lens made of IRG206 glass. One side of the fourth lens 140 is the seventh surface 7, and the other side is the eighth surface 8. The eighth surface 8 is an aspherical surface, which works in conjunction with the third lens 130 to enhance light correction. The aspherical surface fine-tunes the remaining aberrations, ensuring high-resolution imaging details.

[0028] Please see Figure 1 In this embodiment, the uncooled detector 150 includes a protective window 152 made of germanium single crystal. The germanium single crystal material ensures efficient transmission of infrared signals, provides reliable protection, and extends the lifespan of the detector.

[0029] Please see Figure 1 In this embodiment, the imaging focal plane is 154 with a resolution of 1280x1024 and a pixel size of 12μmx12μm. The combination of high resolution and small pixel size enhances the ability to capture details and detect small targets.

[0030] Working principle:

[0031] surface radius of curvature Thickness (gap) Material caliber 1 34.96 5.7 Ge 46 2 24.603 12.86 31.6 3 16.695 4 Ge 21 4 11.838 5.16 14.6 5 -54.853 5.5 IRG206 12.3 6 -27.014 10.71 21 7 68.61 8.5 IRG206 37 8 -42.751 13.38 37 Protect window Infinity 1 Ge Image Infinity 1

[0032] The aspherical surfaces mentioned in the four lenses above are all even-order aspherical surfaces, and their expressions are as follows:

[0033]

[0034] Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a position of height r, c represents the vertex curvature of the surface, k is the conic coefficient, and α2, α3, α4, α5, and α6 are higher-order aspherical coefficients;

[0035] Table 2 shows the aspheric coefficients of surfaces 1, 3, and 6:

[0036] Table 2

[0037]

Claims

1. A long-wave infrared uncooled 180° field-of-view fisheye lens, characterized in that, It includes a first lens (110); a second lens (120) is disposed on one side of the first lens (110), a third lens (130) is disposed on one side of the second lens (120), and a fourth lens (140) is disposed on one side of the third lens (130); the first lens (110) has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the second lens (120) has negative optical power and is a meniscus germanium negative lens with its convex surface facing the object; the third lens (130) has positive optical power and is a meniscus glass positive lens with its concave surface facing the object; the fourth lens (140) has positive optical power and is a biconvex glass positive lens; after the fourth lens (140) is an uncooled detector (150), which includes a protective window (152) and an imaging focal plane (154).

2. The long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The first lens (110) is a negative lens made of germanium single crystal. One side of the first lens (110) is the first surface (1), and the other side of the first lens (110) is the second surface (2). The second surface (2) is an aspherical surface.

3. The long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The second lens (120) is a negative lens made of germanium single crystal. One side of the second lens (120) is the third surface (3), and the other side of the second lens (120) is the fourth surface (4). The fourth surface (4) is an aspherical surface.

4. The long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The third lens (130) is a positive lens made of IRG206 glass. One side of the third lens (130) is the fifth surface (5), and the other side of the third lens (130) is the sixth surface (6). The fifth surface (5) is an aspherical surface.

5. A long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The fourth lens (140) is a positive lens made of IRG206 glass. One side of the fourth lens (140) is the seventh surface (7), and the other side of the fourth lens (140) is the eighth surface (8). The eighth surface (8) is an aspherical surface.

6. A long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The uncooled detector (150) includes a protective window (152) made of germanium single crystal.

7. A long-wave infrared uncooled 180° field-of-view fisheye lens according to claim 1, characterized in that, The imaging focal plane is (154), with a resolution of 1280x1024 and a pixel size of 12μmx12μm.

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