Super-large area array visible light continuous zooming optical system

Abstract

The utility model relates to a super-large area array visible light continuous zooming optical system, belongs to the technical field of visible light imaging, and solves the problems of large size and narrow search range of a zooming optical system in the prior art. The system comprises a front fixed group with positive focal power, a zoom group with negative focal power, a compensation group with positive focal power, a diaphragm, a rear fixed group with positive focal power and an optical filter which are sequentially arranged along an optical axis from an object plane to an image plane, zooming of the optical system is realized through axial movement of the zooming group and the compensation group. The compensation group comprises a first compensation bonding lens formed by a first compensation lens and a second compensation lens, and a second compensation bonding lens formed by a third compensation lens and a fourth compensation lens; the rear fixed group comprises a first rear fixed lens, a first rear fixed balsaming lens formed by a second rear fixed lens and a third rear fixed lens, and a second rear fixed balsaming lens formed by a fourth rear fixed lens and a fifth rear fixed lens which are arranged in sequence. The visible light continuous zooming system is compact in structure, and the focal length change of the visible light continuous zooming system ranges from 20 mm to 100 mm.

Description

Technical Field

[0001] The utility model relates to the technical field of visible light imaging, in particular to an ultra-large array visible light continuous zoom optical system. Background Art

[0002] Medium-wave infrared (MWIR) is the most commonly used wavelength band for airborne electro-optical systems, suitable for day and night detection. However, due to the large pixel size of infrared optical systems and their dependence on temperature differences, they cannot distinguish small details in many scenarios. Infrared lenses are also expensive, making their use costly. Visible light systems have small pixel sizes, high resolution, and images closer to human vision. They are also inexpensive, making visible light continuous zoom systems the optimal choice for both large-field-of-view search and small-field-of-view recognition.

[0003] At present, traditional zoom optical systems are large in size and have a narrow search range, which cannot be adapted to high-definition and large-target visible light cameras. They are also unable to meet the requirements of airborne optoelectronic systems for small size, light weight and long-distance detection capabilities. Utility Model Content

[0004] In view of the above analysis, the present invention aims to provide an ultra-large array visible light continuous zoom optical system to solve the problems of large size and narrow search range of existing zoom optical systems.

[0005] The purpose of this utility model is mainly achieved through the following technical solutions:

[0006] The utility model provides an ultra-large array visible light continuous zoom optical system, comprising a front fixed group with positive optical power, a zoom group with negative optical power, a compensation group with positive optical power, an aperture, a rear fixed group with positive optical power, and a filter, which are arranged in sequence along the optical axis from the object plane to the image plane; wherein the zoom of the optical system is achieved by axial movement of the zoom group and the compensation group; wherein,

[0007] The front fixed group includes a first, a second, and a third front fixed lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second front fixed lenses constitute a front fixed cemented lens;

[0008] The zoom group includes first, second, and third zoom lenses arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third zoom lenses constitute a zoom cemented lens;

[0009] The compensation group includes a first, a second, a third, and a fourth compensation lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second compensation lenses constitute a first compensation cemented lens, and the third and fourth compensation lenses constitute a second compensation cemented lens;

[0010] The rear fixed group includes a first, second, third, fourth and fifth rear fixed lenses arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third rear fixed lenses constitute a first rear fixed cemented lens, and the fourth and fifth rear fixed lenses constitute a second rear fixed cemented lens.

[0011] Based on the further improvement of the above scheme, in the front fixation group,

[0012] The first front fixed lens is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0013] The second front fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller radius of curvature faces the object plane;

[0014] The third front fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0015] The front fixed cemented lens has positive optical power.

[0016] Based on the further improvement of the above solution, in the zoom group,

[0017] The first variable magnification lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0018] The second variable magnification lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0019] The third variable magnification lens is a meniscus lens with positive optical power, with its convex surface facing the object plane;

[0020] The variable power cemented lens has negative optical power.

[0021] Based on the further improvement of the above solution, in the compensation group,

[0022] The first compensation lens is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0023] The second compensating lens is a biconvex lens with positive optical power, wherein the convex surface with a smaller curvature radius faces the object plane;

[0024] The third compensating lens is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0025] The fourth compensating lens is a biconvex lens with positive optical power, wherein the convex surface with a smaller curvature radius faces the object plane;

[0026] The first and second compensating cemented lenses both have positive optical power.

[0027] Based on the further improvement of the above scheme, in the post-fixation group,

[0028] The first rear fixed lens is a meniscus lens with negative optical power, with its concave surface facing the object plane;

[0029] The second rear fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller radius of curvature faces the object plane;

[0030] The third rear fixed lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0031] The fourth rear fixed lens is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0032] The fifth rear fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0033] The first posterior fixed cemented lens has negative optical power, and the second posterior fixed cemented lens has positive optical power.

[0034] Based on a further improvement of the above solution, the zoom group and the compensation group achieve the change from short focus to long focus of the optical system by synchronously moving toward each other along the optical axis;

[0035] The zoom group and the compensation group achieve the change from long focus to short focus of the optical system by synchronously moving relative to each other along the optical axis.

[0036] Based on the further improvement of the above solution, the magnification group and the compensation group are moved along the optical axis through a cam barrel.

[0037] Based on a further improvement of the above solution, the surfaces of the lenses in the front fixed group, the zoom group, the compensation group, and the rear fixed group are all spherical.

[0038] Based on the further improvement of the above solution, the aperture of the optical system is 5, and the adapted focal plane detector array reaches 5120*5120 / 2.5um.

[0039] Based on the further improvement of the above solution, the operating wavelength of the optical system is 0.4um to 0.7um, the total optical length is 130.1mm, and the optical distortion is less than 2%.

[0040] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0041] The utility model provides an ultra-large array visible light continuous zoom optical system, comprising a front fixed group with positive optical power, a zoom group with negative optical power, a compensation group with positive optical power, an aperture, a rear fixed group with positive optical power, and a filter, which are sequentially arranged along the optical axis from the object plane to the image plane. The zoom of the optical system is achieved by axial movement of the zoom group and the compensation group. The front fixed group comprises a front fixed cemented lens and a third front fixed lens formed by sequentially arranged first and second front fixed lenses, the zoom group comprises a first zoom lens, a second and a third zoom lens formed by sequentially arranged second and third zoom lenses, the compensation group comprises a first compensation cemented lens, a third and a fourth compensation lens formed by sequentially arranged first and second compensation lenses, The compensation lens constitutes a second compensating cemented lens, and the rear fixed group includes a first rear fixed lens, a second and a third rear fixed lens which are arranged in sequence to form a first rear fixed cemented lens, and a fourth and a fifth rear fixed lens which constitute a second rear fixed cemented lens, thereby forming a visible light continuous zoom system with a compact structure and a focal length variation of 20mm to 100mm. The system is small in size, light in weight and has the ability of long-distance detection, meeting the requirements of the optical system in the airborne optoelectronic system; and the optical system has a large target surface and a small pixel size, reaching the optical diffraction limit, and is compatible with a variety of ultra-high-definition cameras; in addition, the optical system can also eliminate the problem that the secondary spectrum of visible light continuous zoom is difficult to eliminate, and at the same time solve the contradiction between the volume of the optical system and the search range limitation.

[0042] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following content, and some advantages will become apparent from the description or be understood through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the text and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference symbols denote the same components.

[0044] Figure 1 A schematic diagram of a large field of view optical path in the ultra-large array visible light continuous zoom optical system provided in an embodiment of the present invention;

[0045] Figure 2 Schematic diagram of the middle field of view optical path in the ultra-large array visible light continuous zoom optical system provided in an embodiment of the present utility model;

[0046] Figure 3 A schematic diagram of a small field of view optical path in the ultra-large array visible light continuous zoom optical system provided in an embodiment of the present invention;

[0047] Figure 4 This is a diagram of the optical modulation transfer function of the optical system in a large field of view and short focus working state in an embodiment of the present utility model;

[0048] Figure 5 This is a diagram of the optical modulation transfer function in the optical system in the embodiment of the utility model under the telephoto working state of the field of view;

[0049] Figure 6 This is a diagram of the optical modulation transfer function of the optical system in the embodiment of the utility model in the small field of view and long focus working state;

[0050] Reference numerals:

[0051] 11-first front fixed lens; 12-second front fixed lens; 13-third front fixed lens;

[0052] 21-first zoom lens; 22-second zoom lens; 23-third zoom lens; 31-first compensating lens; 32-second compensating lens; 33-third compensating lens; 34-fourth compensating lens; 41-first rear fixed lens; 42-second rear fixed lens; 43-third rear fixed lens; 44-fourth rear fixed lens; 45-fifth rear fixed lens; 51-filter; 61-aperture. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings 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, and are not used to limit the scope of the present invention.

[0054] A specific embodiment of the present utility model discloses an ultra-large array visible light continuous zoom optical system, such as Figure 1 As shown, the optical system comprises a front fixed group with positive optical power, a zoom group with negative optical power, a compensation group with positive optical power, an aperture 61, a rear fixed group, and a filter 51, which are arranged in sequence along the optical axis from the object plane to the image plane; wherein the zoom of the optical system is achieved by axial movement of the zoom group and the compensation group; wherein,

[0055] The front fixed group includes a first, a second, and a third front fixed lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second front fixed lenses constitute a front fixed cemented lens;

[0056] The zoom group includes a first, a second, and a third zoom lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third zoom lenses constitute a zoom cemented lens;

[0057] The compensation group includes a first, a second, a third, and a fourth compensation lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second compensation lenses constitute a first compensation cemented lens, and the third and fourth compensation lenses constitute a second compensation cemented lens;

[0058] The rear fixed group includes a first, second, third, fourth and fifth rear fixed lenses arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third rear fixed lenses constitute a first rear fixed cemented lens, and the fourth and fifth rear fixed lenses constitute a second rear fixed cemented lens.

[0059] During implementation, in the front fixation group,

[0060] The first front fixed lens 11 is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0061] The second front fixed lens 12 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0062] The third front fixed lens 13 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0063] The front fixed cemented lens has positive optical power.

[0064] During implementation, in the zoom group,

[0065] The first variable magnification lens 21 is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0066] The second variable magnification lens 22 is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0067] The third variable magnification lens 23 is a meniscus lens with positive optical power, with its convex surface facing the object plane;

[0068] The variable power cemented lens has negative optical power.

[0069] When implemented, the compensation group,

[0070] The first compensation lens 31 is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0071] The second compensating lens 32 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0072] The third compensating lens 33 is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0073] The fourth compensating lens 34 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0074] The first and second compensating cemented lenses both have positive optical power.

[0075] During implementation, in the post-fixation group,

[0076] The first rear fixed lens 41 is a meniscus lens with negative optical power, with its concave surface facing the object plane;

[0077] The second rear fixed lens 42 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0078] The third rear fixed lens 43 is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane;

[0079] The fourth rear fixed lens 44 is a meniscus lens with negative optical power, with its convex surface facing the object plane;

[0080] The fifth rear fixed lens 45 is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane;

[0081] The first posterior fixed cemented lens has negative optical power, and the second posterior fixed cemented lens has positive optical power.

[0082] During implementation, the zoom group and the compensation group achieve the change from short focus to long focus of the optical system by synchronously moving toward each other along the optical axis; the zoom group and the compensation group achieve the change from long focus to short focus of the optical system by synchronously moving relative to each other along the optical axis.

[0083] Specifically, the cam barrel is used to achieve the movement of the zoom group and the compensating group along the optical axis. It can be understood that by rotating the cam barrel, the axial displacement of the zoom group and the compensating group along the optical axis is controlled, thereby achieving a change in the focal length of the optical system, effectively reducing the size of the system and making it suitable for small and lightweight airborne optical systems.

[0084] More specifically, the distance between the zoom group and the compensation group is greater than 7 mm to avoid structural interference.

[0085] Specifically, the surfaces of the lenses in the front fixed group, the zoom group, the compensation group, and the rear fixed group are all spherical.

[0086] Specifically, the aperture of the optical system is 5, which is suitable for the focal plane detector array of 5120*5120 / 2.5um.

[0087] Specifically, the operating wavelength of the optical system is 0.4um to 0.7um, the total optical length is 130.1mm, and the optical distortion is less than 2%.

[0088] More specifically, the parameters of each lens of the optical system in this embodiment are shown in Table 1.

[0089] Table 1 Parameters of each lens in the optical system

[0090]

[0091]

[0092] In this embodiment, the optical system's large, medium, and small field of view light paths are arranged as shown in the figure. Figure 1 、 Figure 2 、 Figure 3 As shown; the optical modulation transfer function diagram under the large field of view and short focus working state is as follows Figure 4 As shown; the optical modulation transfer function diagram under the telephoto working state of the field of view is as follows Figure 5 As shown; the optical modulation transfer function diagram under the small field of view and long focus working state is as follows Figure 6 As shown; it can be seen that when the optical system is in long focus, short focus and medium focus, the optical modulation transfer function is greater than 0.2 at the cutoff frequency of 200lp / mm. Considering the processing adjustment factor of 0.6, the human eye can distinguish it after processing and adjustment, which verifies the correctness and effectiveness of this optical system.

[0093] Compared with the prior art, this embodiment provides an ultra-large array visible light continuous zoom optical system, comprising a front fixed group with positive optical power, a zoom group with negative optical power, a compensation group with positive optical power, an aperture, a rear fixed group with positive optical power, and a filter, which are arranged in sequence along the optical axis from the object plane to the image plane. The zoom of the optical system is achieved by axial movement of the zoom group and the compensation group. The front fixed group comprises a front fixed cemented lens and a third front fixed lens formed by first and second front fixed lenses arranged in sequence, the zoom group comprises a first zoom lens, a second and third zoom lenses arranged in sequence, and the compensation group comprises a first compensation cemented lens, a third and fourth compensation lenses arranged in sequence. The fourth compensating lens constitutes a second compensating cemented lens, and the rear fixed group includes a first rear fixed lens, a second and a third rear fixed lens, which are arranged in sequence to form a first rear fixed cemented lens, and a fourth and a fifth rear fixed lens, which constitute a second rear fixed cemented lens. This constitutes a visible light continuous zoom system with a compact structure and a focal length variation of 20 mm to 100 mm. The system is small in size, light in weight, and has the ability to detect at long distances, meeting the requirements of optical systems in airborne optoelectronic systems. In addition, the optical system has a large target surface and a small pixel size, reaching the optical diffraction limit, and is compatible with a variety of ultra-high-definition cameras. In addition, the optical system can also eliminate the problem that the secondary spectrum of visible light continuous zoom is difficult to eliminate, and at the same time solve the contradiction between the volume of the optical system and the limitation of the search range.

[0094] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. An ultra-large array visible light continuous zoom optical system, characterized in that: The optical system comprises a front fixed group with positive optical power, a zoom group with negative optical power, a compensation group with positive optical power, an aperture, a rear fixed group with positive optical power, and a filter, which are arranged in sequence along the optical axis from the object plane to the image plane; wherein the zoom of the optical system is achieved by axial movement of the zoom group and the compensation group; wherein, The front fixed group includes a first, a second, and a third front fixed lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second front fixed lenses constitute a front fixed cemented lens; The zoom group includes first, second, and third zoom lenses arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third zoom lenses constitute a zoom cemented lens; The compensation group includes a first, a second, a third, and a fourth compensation lens arranged in sequence along the optical axis from the object plane to the image plane; wherein the first and second compensation lenses constitute a first compensation cemented lens, and the third and fourth compensation lenses constitute a second compensation cemented lens; The rear fixed group includes a first, second, third, fourth and fifth rear fixed lenses arranged in sequence along the optical axis from the object plane to the image plane; wherein the second and third rear fixed lenses constitute a first rear fixed cemented lens, and the fourth and fifth rear fixed lenses constitute a second rear fixed cemented lens.

2. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: In the pre-fixation group, The first front fixed lens is a meniscus lens with negative optical power, with its convex surface facing the object plane; The second front fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller radius of curvature faces the object plane; The third front fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane; The front fixed cemented lens has positive optical power.

3. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: In the zoom group, The first variable magnification lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane; The second variable magnification lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane; The third variable magnification lens is a meniscus lens with positive optical power, with its convex surface facing the object plane; The variable power cemented lens has negative optical power.

4. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: In the compensation group, The first compensation lens is a meniscus lens with negative optical power, with its convex surface facing the object plane; The second compensating lens is a biconvex lens with positive optical power, wherein the convex surface with a smaller curvature radius faces the object plane; The third compensating lens is a meniscus lens with negative optical power, with its convex surface facing the object plane; The fourth compensating lens is a biconvex lens with positive optical power, wherein the convex surface with a smaller curvature radius faces the object plane; The first and second compensating cemented lenses both have positive optical power.

5. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: In the post-fixation group, The first rear fixed lens is a meniscus lens with negative optical power, with its concave surface facing the object plane; The second rear fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller radius of curvature faces the object plane; The third rear fixed lens is a biconcave lens with negative optical power, and the concave surface with a larger curvature radius faces the object plane; The fourth rear fixed lens is a meniscus lens with negative optical power, with its convex surface facing the object plane; The fifth rear fixed lens is a biconvex lens with positive optical power, and the convex surface with a smaller curvature radius faces the object plane; The first posterior fixed cemented lens has negative optical power, and the second posterior fixed cemented lens has positive optical power.

6. The ultra-large array visible light continuous zoom optical system according to claim 3 or 4, characterized in that: The zoom group and the compensation group move synchronously toward each other along the optical axis to achieve the change from short focus to long focus of the optical system; The zoom group and the compensation group achieve the change from long focus to short focus of the optical system by synchronously moving relative to each other along the optical axis.

7. The ultra-large array visible light continuous zoom optical system according to claim 6, characterized in that: The cam tube is used to realize the movement of the zoom group and the compensation group along the optical axis.

8. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: The surfaces of the lenses in the front fixed group, the zoom group, the compensation group and the rear fixed group are all spherical.

9. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: The aperture of the optical system is 5, and the adapted focal plane detector array reaches 5120*5120 / 2.5um.

10. The ultra-large array visible light continuous zoom optical system according to claim 1, characterized in that: The operating wavelength of the optical system is 0.4um to 0.7um, the total optical length is 130.1mm, and the optical distortion is less than 2%.

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