Optical system
By designing lens combinations and optimizing aperture stop positions, combined with filter settings, the problems of narrow band range and small aperture in existing optical systems have been solved, achieving high resolution and multi-band applications for small pixels, making it suitable for optical systems used both day and night.
Patent Information
- Application Number
- CN202520605802.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2035-04-01
AI Technical Summary
Existing optical systems have a narrow applicable wavelength range and small aperture, making them unable to achieve clear imaging in low-light environments, especially at night, and unable to meet the imaging requirements of CCD chips. Furthermore, large aperture systems are mainly designed for large pixels and do not address high resolution for small pixels.
Design an optical system comprising lenses and detectors arranged sequentially from the object side to the image side. The lens assembly adopts a spherical design, the aperture stop is attached to the image side of the cemented lens, and a filter is placed between the sixth lens and the detector. The lens materials and focal lengths meet specific ranges to achieve high resolution and multi-band applications with small pixels.
It achieves high-resolution imaging with small pixels, corrects various aberrations, covers visible light, near infrared and short-wave bands, and is applicable to wavelengths of 0.4um-1.7um. It is compatible with detectors with pixel sizes of 2.7 micrometers and above and provides clear imaging within a focal length range of 25mm to 50mm.
Smart Images
Figure CN223977418U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of optical imaging technology, and in particular to an optical system. Background Technology
[0002] In recent years, as the application range of optical systems has become increasingly wide, people have placed higher demands on the applicable illumination range of optical systems for both day and night use. However, existing optical systems generally have the following shortcomings:
[0003] 1. It has a narrow spectral range and can only be used in daylight conditions. In low-light environments at night, it needs infrared supplemental lighting to achieve clear imaging. It cannot cover both near-infrared and short-wave spectrum at the same time.
[0004] 2. The aperture is small, which cannot meet the minimum imaging illumination requirements of CCD chips under low light conditions, resulting in unclear imaging and poor performance in both day and night applications.
[0005] 3. Currently, large-aperture optical systems mainly focus on large pixels, and have not yet addressed the issue of high resolution with small pixels.
[0006] Therefore, a new type of optical system is urgently needed. Utility Model Content
[0007] Based on the above analysis, the present invention aims to provide an optical system to solve the problems of narrow applicable wavelength range, small aperture and large pixel size in existing optical systems.
[0008] The objective of this utility model is mainly achieved through the following technical solutions:
[0009] The optical system includes a first lens, a second lens, a cemented lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a detector arranged sequentially from the object side to the image side;
[0010] The detector has 1500 or fewer pixels in the horizontal direction and 1200 or fewer pixels in the vertical direction.
[0011] Based on further improvements to the above optical system, the optical system also includes an aperture stop;
[0012] The aperture stop is attached to the image side of the cemented lens.
[0013] Based on further improvements to the above optical system, the optical system also includes a filter;
[0014] The filter is disposed between the sixth lens and the detector;
[0015] The wavelength range of the filter is 0.4um-1.7um.
[0016] Based on further improvements to the aforementioned optical system, the assembly half-apertures of the first lens, second lens, cemented lens, third lens, fourth lens, fifth lens, and sixth lens are 17.9 mm, 10.9 mm, 7.8 mm, 7.8 mm, 7.8 mm, and 6.3 mm, respectively.
[0017] Based on further improvements to the optical system described above, the optical system is scaled proportionally to achieve a focal length range of 25mm to 50mm.
[0018] Based on further improvements to the aforementioned optical system, the focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy the following conditions:
[0019] 4.5 <f1 / f<5;
[0020] 3 <f2 / f<3.5;
[0021] -1.5 <f3 / f<-1;
[0022] 7.5 <f4 / f<8;
[0023] 1 <f5 / f<1.2;
[0024] 1.1 <f6 / f<1.3;
[0025] -1.6 <f7 / f<-1.4;
[0026] Where f, f1, f2, f3, f4, f5, f6 and f7 represent the focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens, respectively.
[0027] Based on further improvements to the aforementioned optical system, the thickness of the first lens is 2.97 mm, the thickness of the second lens is 2.55 mm, the thickness of the first cemented lens is 3.85 mm, the thickness of the second cemented lens is 1.55 mm, the thickness of the third lens is 3.58 mm, the thickness of the fourth lens is 2.51 mm, the thickness of the fifth lens is 2.48 mm, and the thickness of the sixth lens is 2.59 mm.
[0028] The distance between the first lens and the second lens is 28.02 mm, the distance between the second lens and the first cemented lens is 6.76 mm, the distance between the second cemented lens and the third lens is 9.643 mm, the distance between the third lens and the fourth lens is 0.126 mm, the distance between the fourth lens and the fifth lens is 0.1 mm, the distance between the fifth lens and the sixth lens is 0.1 mm, and the distance between the sixth lens and the detector is 5.77 mm.
[0029] Based on the further improvements to the optical system described above, the object-side and image-side radii of curvature of the first lens are 49.66 mm and 87.346 mm, respectively.
[0030] The object-side and image-side radii of curvature of the second lens are 43.61 mm and -726.7 mm, respectively.
[0031] The object-side and image-side radii of curvature of the first cemented lens are 16.27 mm and -21.33 mm, respectively.
[0032] The object-side and image-side radii of curvature of the second cemented lens are 21.33 mm and 15.816 mm, respectively.
[0033] The object-side and image-side radii of curvature of the third lens are -12.599 mm and -13.36 mm, respectively.
[0034] The object-side and image-side radii of curvature of the fourth lens are 29.55 mm and -53.76 mm, respectively.
[0035] The object-side and image-side radii of curvature of the fifth lens are 12.38 mm and 26.67 mm, respectively.
[0036] The object-side and image-side radii of curvature of the sixth lens are 7.065 mm and 4.834 mm, respectively.
[0037] Based on further improvements to the optical system described above, the refractive index of the first lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20.
[0038] The refractive index of the second lens ranges from 1.43 to 1.55, and the Abbe number ranges from 75 to 90.
[0039] The refractive index of the third lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20.
[0040] Based on further improvements to the above optical system, the cemented lens includes a first cemented lens and a second cemented lens arranged sequentially from the object side to the image side;
[0041] The first cemented lens has a refractive index range of 1.55 to 1.65 and an Abbe number range of 65 to 75; the second cemented lens has a refractive index range of 1.85 to 1.95 and an Abbe number range of 15 to 20.
[0042] The fourth lens has a refractive index range of 1.65 to 1.85 and an Abbe number range of 30 to 50; the fifth lens has a refractive index range of 1.65 to 1.85 and an Abbe number range of 30 to 50; and the sixth lens has a refractive index range of 1.75 to 1.9 and an Abbe number range of 40 to 50.
[0043] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:
[0044] 1. By using the first lens, second lens, cemented lens, third lens, fourth lens, fifth lens and sixth lens arranged sequentially from the object side to the image side, the detector has less than or equal to 1500 pixels in the horizontal direction and less than or equal to 1200 pixels in the vertical direction, so that the optical system can also achieve clear imaging with small pixel high resolution.
[0045] 2. By attaching the aperture stop to the image side of the cemented lens, the effect of correcting various aberrations, including coma, is improved;
[0046] 3. Place a filter between the sixth lens and the detector, and place a filter with any wavelength in the range of 0.4um to 1.7um to realize multi-band multispectral applications.
[0047] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing this invention. The objectives and other advantages of this invention can be realized and obtained from the details specifically pointed out in the text and accompanying drawings. Attached Figure Description
[0048] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.
[0049] Figure 1 This is a schematic diagram of the structure of an optical system provided by this utility model.
[0050] Figure label:
[0051] 1-First lens; 2-Second lens; 3-Cemented lens; 4-Third lens;
[0052] 5-Fourth lens; 6-Fifth lens; 7-Sixth lens; 8-Filter;
[0053] 9-Detector. Detailed Implementation
[0054] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.
[0055] A specific embodiment of this utility model discloses an optical system, such as... Figure 1 As shown, the optical system includes a first lens 1, a second lens 2, a cemented lens 3, a third lens 4, a fourth lens 5, a fifth lens 6, a sixth lens 7, and a detector 9 arranged sequentially from the object side to the image side;
[0056] The detector 9 has 1500 or fewer pixels in the horizontal direction and 1200 or fewer pixels in the vertical direction.
[0057] Specifically, such as Figure 1 As shown, the optical system combines a first lens 1, a second lens 2, a cemented lens 3, a third lens 4, a fourth lens 5, a fifth lens 6, and a sixth lens 7 arranged sequentially from the object side to the image side, to create an image on the detector with a horizontal pixel count of less than or equal to 1500 and a vertical pixel count of less than or equal to 1200.
[0058] Preferably, the spacing between the pixels of the detector ranges from 2.7µm to 13µm, enabling the optical system to operate at high resolution with small pixels. For example, the detector has a resolution of 800*600.
[0059] Specifically, the first lens 1, the second lens 2, the cemented lens 3, the third lens 4, the fourth lens 5, the fifth lens 6, and the sixth lens 7 all adopt a spherical design and use a combination of positive and negative lenses to meet the application requirements of small pixel wide band large aperture high resolution.
[0060] Preferably, the optical system further includes an aperture stop;
[0061] The aperture stop is attached to the image side of the cemented lens 3.
[0062] Specifically, such as Figure 1 As shown, the cemented lens 3 includes an object plane on the left and an image plane on the right, with the aperture stop attached to the image plane of the cemented lens 3.
[0063] It is worth noting that, since the position of the aperture stop in the optical system plays a crucial role in correcting various aberrations such as coma, attaching the aperture stop to the image side of the cemented lens 3 can improve the effect of correcting various aberrations, including coma.
[0064] Preferably, such as Figure 1 As shown, the optical system also includes a filter 8;
[0065] The filter 8 is disposed between the sixth lens 7 and the detector 9;
[0066] The wavelength range of the filter 8 is 0.4um-1.7um.
[0067] Specifically, a filter interface is provided between the sixth lens 7 of the optical system and the detector 9, which can accommodate filters of any wavelength from 0.4um to 1.7um. The application of multi-band multispectral filtering from 0.4um to 1.7um is realized by placing a filter switching mechanism.
[0068] Preferably, the assembly half-apertures of the first lens 1, the second lens 2, the cemented lens 3, the third lens 4, the fourth lens 5, the fifth lens 6, and the sixth lens 7 are 17.9 mm, 10.9 mm, 7.8 mm, 7.8 mm, 7.8 mm, 7.8 mm, and 6.3 mm, respectively.
[0069] Specifically, such as Figure 1 As shown, the assembly half-aperture of each lens can be expressed as half the distance difference between the highest and lowest points of each lens.
[0070] It is understandable that the center point of all the lenses is on the same horizontal line.
[0071] Preferably, the focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy the following conditions:
[0072] 4.5 <f1 / f<5;
[0073] 3 <f2 / f<3.5;
[0074] -1.5 <f3 / f<-1;
[0075] 7.5 <f4 / f<8;
[0076] 1 <f5 / f<1.2;
[0077] 1.1 <f6 / f<1.3;
[0078] -1.6 <f7 / f<-1.4;
[0079] Where f, f1, f2, f3, f4, f5, f6 and f7 represent the focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens, respectively.
[0080] Specifically, the thickness of the first lens is 2.97 mm, the thickness of the second lens is 2.55 mm, the thickness of the first cemented lens is 3.85 mm, the thickness of the second cemented lens is 1.55 mm, the thickness of the third lens is 3.58 mm, the thickness of the fourth lens is 2.51 mm, the thickness of the fifth lens is 2.48 mm, and the thickness of the sixth lens is 2.59 mm.
[0081] The distance between the first lens and the second lens is 28.02 mm, the distance between the second lens and the first cemented lens is 6.76 mm, the distance between the second cemented lens and the third lens is 9.643 mm, the distance between the third lens and the fourth lens is 0.126 mm, the distance between the fourth lens and the fifth lens is 0.1 mm, the distance between the fifth lens and the sixth lens is 0.1 mm, and the distance between the sixth lens and the detector is 5.77 mm.
[0082] Specifically, the object-side and image-side radii of curvature of the first lens are 49.66 mm and 87.346 mm, respectively;
[0083] The object-side and image-side radii of curvature of the second lens are 43.61 mm and -726.7 mm, respectively.
[0084] The object-side and image-side radii of curvature of the first cemented lens are 16.27 mm and -21.33 mm, respectively.
[0085] The object-side and image-side radii of curvature of the second cemented lens are 21.33 mm and 15.816 mm, respectively.
[0086] The object-side and image-side radii of curvature of the third lens are -12.599 mm and -13.36 mm, respectively.
[0087] The object-side and image-side radii of curvature of the fourth lens are 29.55 mm and -53.76 mm, respectively.
[0088] The object-side and image-side radii of curvature of the fifth lens are 12.38 mm and 26.67 mm, respectively.
[0089] The object-side and image-side radii of curvature of the sixth lens are 7.065 mm and 4.834 mm, respectively.
[0090] Specifically, by setting the spacing, thickness, and radius of curvature of each lens in an optical system, the optical system can achieve the following specifications:
[0091] Focal length: 24.4mm;
[0092] Relative aperture: 1.0;
[0093] Operating wavelength: 0.45μm~1.7μm;
[0094] Field of view: 8°(H) × 6°(V);
[0095] Compatible detector specifications: 1500×1200.
[0096] Preferably, the refractive index of the first lens is in the range of 1.85 to 1.95, and the Abbe number is in the range of 15 to 20;
[0097] The refractive index of the second lens ranges from 1.43 to 1.55, and the Abbe number ranges from 75 to 90.
[0098] The refractive index of the third lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20.
[0099] Specifically, the purpose of eliminating chromatic aberration is achieved by using a combination of materials for the first lens 1, the second lens 2, and the third lens 4.
[0100] It is worth noting that the first lens 1 and the third lens 4 use high refractive index low Abbe number materials, which allows light to bend rapidly, while the second lens 2 uses low refractive index high Abbe number materials, which enables the optical system to better adapt to wide-band requirements.
[0101] Preferably, the cemented lens includes a first cemented lens and a second cemented lens arranged sequentially from the object side to the image side;
[0102] The first cemented lens has a refractive index range of 1.55 to 1.65 and an Abbe number range of 65 to 75; the second cemented lens has a refractive index range of 1.85 to 1.95 and an Abbe number range of 15 to 20.
[0103] The fourth lens has a refractive index range of 1.65 to 1.85 and an Abbe number range of 30 to 50; the fifth lens has a refractive index range of 1.65 to 1.85 and an Abbe number range of 30 to 50; and the sixth lens has a refractive index range of 1.75 to 1.9 and an Abbe number range of 40 to 50.
[0104] Specifically, such as Figure 1As shown, the cemented lens consists of a first cemented lens on the left and a second cemented lens on the right, achieving large aperture and large image plane aberration correction, making the optical system compact, with a large aperture and a wide-band day and night global surface.
[0105] It is worth noting that the optical system has an F-number of at least 1 and is applicable to wavelengths from 450nm to 1700nm, covering visible light, near-infrared, and shortwave. It can be adapted to and is compatible with detectors with a pixel size of 2.7 micrometers and above. All lenses adopt a spherical design to reduce production costs. The combination of positive and negative lenses achieves passive and thermal optical processing, further reducing production costs and filling the demand for small-pixel, wide-band, large-aperture, and high-resolution applications.
[0106] Preferably, the optical system is scaled proportionally so that the focal length range of the optical system is 25mm to 50mm.
[0107] Specifically, the focal length of the optical system can be adjusted by scaling proportionally, so that the optical system can produce clear images within a focal length range of 25mm to 50mm.
[0108] Compared with the prior art, the optical system provided by this utility model embodiment uses a first lens, a second lens, a cemented lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side. The detector has a horizontal pixel count of less than or equal to 1500 and a vertical pixel count of less than or equal to 1200, enabling the optical system to achieve clear imaging even with small pixel resolution. At the same time, by attaching the aperture stop to the image side of the cemented lens, the effect of correcting various aberrations, including coma, is improved. Furthermore, by placing a filter between the sixth lens and the detector, a filter with any wavelength range from 0.4µm to 1.7µm can be placed to achieve multi-band multispectral applications.
[0109] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.
Claims
1. An optical system characterized by comprising: The optical system comprises, in order from the object side to the image side, a first lens, a second lens, a cemented lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a detector. The detector has a pixel number less than or equal to 1500 in the horizontal direction and a pixel number less than or equal to 1200 in the vertical direction.
2. The optical system of claim 1, wherein The optical system further comprises an aperture stop. The aperture stop is attached to the image side of the cemented lens.
3. The optical system of claim 2, wherein, The optical system further comprises a filter. The filter is arranged between the sixth lens and the detector. The filter has a wavelength range of 0.4um-1.7um.
4. The optical system of claim 3, wherein The assembly half radii of the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens are 17.9mm, 10.9mm, 7.8mm, 7.8mm, 7.8mm, 7.8mm and 6.3mm respectively.
5. The optical system of claim 1, wherein The optical system is scaled proportionally so that the focal length range of the optical system is 25mm-50mm.
6. The optical system of claim 5, wherein, The focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens satisfy the following conditions: 4.5 3 -1.5 7.5 1 1.1 -1.6 wherein f, f1, f2, f3, f4, f5, f6 and f7 represent the focal lengths of the optical system, the first lens, the second lens, the cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens respectively.
7. The optical system of claim 4, wherein The thicknesses of the first lens, the second lens, the first cemented lens, the second cemented lens, the third lens, the fourth lens, the fifth lens and the sixth lens are 2.97mm, 2.55mm, 3.85mm, 1.55mm, 3.58mm, 2.51mm, 2.48mm and 2.59mm respectively. The spacings between the first lens and the second lens, the second lens and the first cemented lens, the second cemented lens and the third lens, the third lens and the fourth lens, the fourth lens and the fifth lens, the fifth lens and the sixth lens and the sixth lens and the detector are 28.02mm, 6.76mm, 9.643mm, 0.126mm, 0.1mm, 0.1mm and 5.77mm respectively.
8. The optical system of claim 7, wherein, The radii of curvature of the object side and the image side of the first lens are 49.66mm and 87.346mm respectively. The radii of curvature of the object side and the image side of the second lens are 43.61mm and -726.7mm respectively. The radii of curvature of the object side and the image side of the first cemented lens are 16.27mm and -21.33mm respectively. The radii of curvature of the object side and the image side of the second cemented lens are 21.33mm and 15.816mm respectively. The curvature radius of the object side and the image side of the third lens is -12.599mm and -13.36mm respectively; The curvature radius of the object side and the image side of the fourth lens is 29.55mm and -53.76mm respectively; The curvature radius of the object side and the image side of the fifth lens is 12.38mm and 26.67mm respectively; The curvature radius of the object side and the image side of the sixth lens is 7.065mm and 4.834mm respectively.
9. The optical system of claim 1, wherein, The refractive index of the first lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20; The refractive index of the second lens ranges from 1.43 to 1.55, and the Abbe number ranges from 75 to 90; The refractive index of the third lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20.
10. The optical system of claim 9, wherein, The cemented lens comprises a first cemented lens and a second cemented lens arranged in sequence from the object side to the image side; The refractive index of the first cemented lens ranges from 1.55 to 1.65, and the Abbe number ranges from 65 to 75; the refractive index of the second cemented lens ranges from 1.85 to 1.95, and the Abbe number ranges from 15 to 20; The refractive index of the fourth lens ranges from 1.65 to 1.85, and the Abbe number ranges from 30 to 50; the refractive index of the fifth lens ranges from 1.65 to 1.85, and the Abbe number ranges from 30 to 50; the refractive index of the sixth lens ranges from 1.75 to 1.9, and the Abbe number ranges from 40 to 50.