Visible light and infrared dual-mode seeker optical system and imaging method

Abstract

The invention relates to the technical field of optics, in particular to a visible light and infrared dual-mode seeker optical system and an imaging method.The visible light and infrared dual-mode seeker optical system comprises an along-light-path fairing, an infrared imaging optical module and a visible light imaging optical module, and the infrared imaging optical module is arranged on one side of the along-light-path fairing; an opening is formed in the side, close to the light path fairing, of the infrared imaging optical module, and the visible light imaging optical module is arranged in the opening. The visible light imaging system module is only composed of the visible light first lens, the visible light second lens, the visible light third lens and the prism, the structure is simple and compact, the size is small, the weight is light, the research and development cost is low, the machining and installation adjustment difficulty is effectively reduced, operation is easy, and cost is low. In this way, the technical problems that in the prior art, an optical system is limited in focal length expansion, redundant in system size, poor in imaging quality and complex in structure are solved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and particularly to an optical system and imaging method for a visible light and infrared dual-mode seeker. Background Art

[0002] The use of visible light and infrared imaging compound homing technology has multiple advantages: it can improve target recognition and guidance accuracy; implementing passive detection and tracking helps reduce exposure and improve the survivability of the system in a hostile environment; the dual-mode compound system can more effectively counter the target's stealth technology because it is almost impossible to simultaneously perform visible light and infrared imaging on the same target; the seeker dual-mode system obtains visible light and infrared images with their respective characteristics, making target recognition more effective; in addition, the system has all-weather and all-round target detection capabilities, and has the characteristics of small size, light weight, and low cost, and can also achieve the "fire-and-forget" ability.

[0003] In the prior art, Patent 201822027153.1 describes a visible light and long-wave infrared coaxial common aperture compound optical system, whose structural design uses an infrared lens' first lens to embed a visible light lens and a visible light detector. However, this design severely limits the length of the visible light system and restricts the focal length of the visible light. On the other hand, Patent 201910315209.X provides a visible light and long-wave infrared common aperture compound imaging optical system, which avoids the space occupied by the visible light optical path in the infrared optical path and ensures the action distance of the visible light at the same time. However, this system uses a combination of a prism and a mirror, resulting in a large size and volume, and also increasing the difficulty of debugging. Secondly, Patent 202311098207.2 discloses an optical system for a television and infrared dual-mode seeker, which uses the method of folding the optical path, similarly limiting the length of the visible light system and being restricted by the focal length of the visible light.

[0004] In summary, the existing optical systems have problems such as limited focal length expansion, redundant system volume, poor imaging quality, and complex structure. Summary of the Invention

[0005] The purpose of the present invention is to provide an optical system and imaging method for a visible light and infrared dual-mode seeker, aiming to solve the technical problems of limited focal length expansion, redundant system volume, poor imaging quality, and complex structure in the existing optical systems.

[0006] To achieve the above object, an optical system for a visible light and infrared dual-mode seeker adopted by the present invention includes an on-optical-path fairing, an infrared imaging optical module, and a visible light imaging optical module. The infrared imaging optical module is disposed on one side of the on-optical-path fairing, and an opening is provided on the side of the infrared imaging optical module close to the on-optical-path fairing. The visible light imaging optical module is placed in the opening.

[0007] Among them, the infrared imaging optical module includes a first infrared lens, a second infrared lens, and a third infrared lens. The first infrared lens, the second infrared lens, and the third infrared lens are all disposed on the front side of the detector, and the first infrared lens, the second infrared lens, and the third infrared lens are arranged in sequence from the on-optical-path fairing to the detector.

[0008] Among them, the visible light imaging optical module includes a lens group and a prism. The lens group is disposed in the opening, and the prism is disposed on the side of the first infrared lens close to the second infrared lens.

[0009] Among them, the lens group includes a first visible light lens, a second visible light lens, and a third visible light lens. The first visible light lens, the second visible light lens, and the third visible light lens are all disposed in the opening, and the first visible light lens, the second visible light lens, and the third visible light lens are arranged in sequence from the on-optical-path fairing to the detector.

[0010] Among them, the working wavelength band of the infrared imaging optical module is 8μm - 12μm, and the field of view angle ≥ 8.8°×7°; the working wavelength band of the visible light imaging optical module is 0.45μm - 0.85μm, and the field of view angle ≥ 9.9°×7.9°.

[0011] The present invention also provides an optical system imaging method, which is applied to the visible light and infrared dual-mode seeker optical system as described above.

[0012] The visible light imaging optical module reflects visible light to a visible light detector through the prism for imaging.

[0013] An optical system for a visible light and infrared dual-mode seeker and an imaging method thereof according to the present invention. The visible light imaging system module of the present invention is only composed of the first visible light lens, the second visible light lens, the third visible light lens, and the prism. It has a simple and compact structure, small volume and light weight, low R & D cost, effectively reduces the processing and alignment difficulty, and is easy to operate. In this way, the technical problems of limited focal length expansion, redundant system volume, poor imaging quality, and complex structure existing in the prior art optical system are solved.

[0014] It can effectively avoid the influence of the heat generation of the visible light detector on the infrared optical path imaging quality, further improve the visible light focal length and recognition distance, the visible light and infrared imaging are independent, and it has a small volume and light weight, excellent imaging quality, and a simple structure that is easy to assemble and adjust.

[0015] The visible light imaging optical module and the infrared imaging optical module image independently of each other without interference. While meeting the optical indicators, it has a simple and compact structure, a small volume, a light weight, a low R & D cost, effectively reduces the processing and assembly and adjustment difficulties, and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of the optical system of the visible light and infrared dual-mode seeker of the present invention.

[0018] Figure 2 It is a schematic diagram of the infrared imaging optical module of the present invention.

[0019] Figure 3 It is a schematic diagram of the 20°C infrared optical MTF of the present invention.

[0020] Figure 4 It is a schematic diagram of the 20°C infrared optical blur spot diameter of the present invention.

[0021] Figure 5 It is a schematic diagram of the -40°C infrared optical MTF of the present invention.

[0022] Figure 6 It is a schematic diagram of the -40°C infrared optical blur spot diameter of the present invention.

[0023] Figure 7 It is a schematic diagram of the -60°C infrared optical MTF of the present invention.

[0024] Figure 8 It is a schematic diagram of the -60°C infrared optical blur spot diameter of the present invention.

[0025] Figure 9 It is a schematic diagram of the field curvature and distortion of the infrared optical system of the present invention.

[0026] Figure 10 It is a schematic diagram of the visible light optical module of the present invention.

[0027] Figure 11It is a schematic diagram of the 20°C visible light optical MTF of the present invention.

[0028] Figure 12 It is a schematic diagram of the 20°C visible light optical spot diameter of the present invention.

[0029] Figure 13 It is a schematic diagram of the -40°C visible light optical MTF of the present invention.

[0030] Figure 14 It is a schematic diagram of the -40°C visible light optical spot diameter of the present invention.

[0031] Figure 15 It is a schematic diagram of the 60°C visible light optical MTF of the present invention.

[0032] Figure 16 It is a schematic diagram of the 60°C visible light optical spot diameter of the present invention.

[0033] Figure 17 It is a schematic diagram of the field curvature and distortion of the visible light optical system of the present invention.

[0034] 1 - Optical path fairing along the way, 2 - Infrared imaging optical module, 3 - Visible light imaging optical module, 4 - First infrared lens, 5 - Second infrared lens, 6 - Third infrared lens, 7 - First visible light lens, 8 - Second visible light lens, 9 - Third visible light lens, 10 - Prism. Detailed implementation mode

[0035] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation of the present invention.

[0036] Please refer to Figures 1 to 17 , where Figure 1 It is a schematic diagram of the structure of the optical system of the visible light and infrared dual-mode seeker of the present invention. Figure 2 It is a schematic diagram of the infrared imaging optical module of the present invention. Figure 3 It is a schematic diagram of the 20°C infrared optical MTF of the present invention. Figure 4 It is a schematic diagram of the 20°C infrared optical spot diameter of the present invention. Figure 5 It is a schematic diagram of the -40°C infrared optical MTF of the present invention. Figure 6 It is a schematic diagram of the -40°C infrared optical spot diameter of the present invention. Figure 7 It is a schematic diagram of the -60°C infrared optical MTF of the present invention. Figure 8 It is a schematic diagram of the -60°C infrared optical spot diameter of the present invention. Figure 9 It is a schematic diagram of the field curvature and distortion of the infrared optical system of the present invention. Figure 10It is a schematic diagram of the visible light optical module of the present invention. Figure 11 It is a schematic diagram of the visible light optical MTF at 20°C of the present invention. Figure 12 It is a schematic diagram of the visible light optical spot diameter at 20°C of the present invention. Figure 13 It is a schematic diagram of the visible light optical MTF at -40°C of the present invention. Figure 14 It is a schematic diagram of the visible light optical spot diameter at -40°C of the present invention. Figure 15 It is a schematic diagram of the visible light optical MTF at 60°C of the present invention. Figure 16 It is a schematic diagram of the visible light optical spot diameter at 60°C of the present invention. Figure 17 It is a schematic diagram of the field curvature and distortion of the visible light optical system of the present invention.

[0037] The present invention provides a visible light and infrared dual-mode seeker optical system, including an on-path fairing 1, an infrared imaging optical module 2, and a visible light imaging optical module 3 along the optical path. The infrared imaging optical module 2 is disposed on one side of the on-path fairing 1, and the infrared imaging optical module 2 has an opening on the side close to the on-path fairing 1, and the visible light imaging optical module 3 is placed in the opening.

[0038] The infrared imaging optical module 2 includes an infrared first lens 4, an infrared second lens 5, and an infrared third lens 6. The infrared first lens 4, the infrared second lens 5, and the infrared third lens 6 are all disposed on the front side of the detector, and along the on-path fairing 1 to the detector are the infrared first lens 4, the infrared second lens 5, and the infrared third lens 6 in sequence.

[0039] The visible light imaging optical module 3 includes a lens group and a prism 10. The lens group is disposed in the opening, and the prism 10 is disposed on the side of the infrared first lens 4 close to the infrared second lens 5.

[0040] The lens group includes a visible light first lens 7, a visible light second lens 8, and a visible light third lens 9. The visible light first lens 7, the visible light second lens 8, and the visible light third lens 9 are all disposed in the opening, and along the on-path fairing 1 to the detector are the visible light first lens 7, the visible light second lens 8, and the visible light third lens 9 in sequence.

[0041] The working wavelength band of the infrared imaging optical module 2 is 8μm - 12μm, and the field of view angle ≥ 8.8°×7°; the working wavelength band of the visible light imaging optical module 3 is 0.45μm - 0.85μm, and the field of view angle ≥ 9.9°×7.9°.

[0042] For this specific embodiment, the visible light imaging system module of the present invention is only composed of the first visible light lens 7, the second visible light lens 8, the third visible light lens 9, and the prism 10. It has a simple and compact structure, small size, light weight, low R & D cost, effectively reduces the processing and alignment difficulties, and is easy to operate. In this way, the technical problems of the existing optical systems, such as limited focal length expansion, redundant system volume, poor imaging quality, and complex structure, are solved.

[0043] It can effectively avoid the influence of the heat generated by the visible light detector on the imaging quality of the infrared optical path, can further increase the visible light focal length and recognition distance, the visible light and infrared imaging are independent, and it has a small volume and light weight, excellent imaging quality, and a simple structure that is easy to assemble and adjust.

[0044] The visible light imaging optical module 3 and the infrared imaging optical module 2 image independently of each other. While meeting the optical specifications, it has a simple and compact structure, small size, light weight, low R & D cost, effectively reduces the processing and alignment difficulties, and is easy to operate.

[0045] The present invention also provides an optical system imaging method, which is applied to the visible light and infrared dual-mode seeker optical system as described above.

[0046] The visible light imaging optical module 3 reflects the visible light to the visible light detector through the prism 10 for imaging. In the present invention, the working band of the visible light imaging optical module 3 is 0.45μm - 0.85μm, the field of view angle ≥ 9.9°×7.9°, the focal length is 40mm, and the relative aperture is 1 / 5.

[0047] The specific parameters of the visible light optical imaging module are shown in Table 1:

[0048]

[0049] In Table 1, the radius of curvature R1 and R2 respectively refer to the radius of curvature of the front and back surfaces of each lens, and the thickness D is the central thickness of the lens.

[0050] In the present invention, the working band of the infrared optical imaging module is 8μm - 12μm, the field of view angle ≥ 8.8°×7.03°, the focal length is 50mm, the F number is 1, and the operating temperature is -40°C to +60°C.

[0051] The specific parameters of the infrared optical imaging system are shown in Table 2:

[0052]

[0053] In Table 2, the back surface of No. 1 is an aspherical surface, the back surface of No. 2 is an aspherical surface, and No. 3 is a double-sided aspherical surface.

[0054] The definition of the displacement in the optical axis direction of the aspheric surface with respect to the surface fixed point is as follows:

[0055]

[0056]

[0057] Among them, Z: displacement in the optical axis direction, c: height of the optical axis, r: paraxial curvature radius, K: conic coefficient, and A, B, C, D, E, F are aspheric coefficients.

[0058] Using an optical system and an imaging method for a visible light and infrared dual-mode seeker of the present invention, the visible light imaging system module of the present invention is only composed of the first visible light lens 7, the second visible light lens 8, the third visible light lens 9, and the prism 10. It has a simple and compact structure, small volume and light weight, low R & D cost, effectively reduces the processing and alignment difficulty, and is easy to operate. In this way, the technical problems of limited focal length expansion, redundant system volume, poor imaging quality, and complex structure existing in the prior art optical system are solved.

[0059] It can effectively avoid the influence of the heat generated by the visible light detector on the imaging quality of the infrared optical path, can further improve the visible light focal length and recognition distance, the visible light and infrared imaging are independent, and it has a small volume and light weight, excellent imaging quality, and a simple structure that is easy to align.

[0060] The visible light imaging optical module 3 and the infrared imaging optical module 2 image independently of each other without interference. While meeting the optical indicators, it has a simple and compact structure, small volume and light weight, low R & D cost, effectively reduces the processing and alignment difficulty, and is easy to operate.

[0061] The above-disclosed is only a preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand the entire or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A visible light and infrared dual-mode seeker optical system, characterized in that it includes an along-optical-path fairing, an infrared imaging optical module, and a visible light imaging optical module. The infrared imaging optical module is arranged on one side of the along-optical-path fairing, and the infrared imaging optical module has an opening on the side close to the along-optical-path fairing, and the visible light imaging optical module is placed in the opening.

2. The visible light and infrared dual-mode seeker optical system according to claim 1, characterized in that the infrared imaging optical module includes an infrared first lens, an infrared second lens, and an infrared third lens. The infrared first lens, the infrared second lens, and the infrared third lens are all arranged in front of the detector, and the infrared first lens, the infrared second lens, and the infrared third lens are arranged in sequence from the along-optical-path fairing to the detector.

3. The visible light and infrared dual-mode seeker optical system according to claim 2, characterized in that the visible light imaging optical module includes a lens group and a prism. The lens group is arranged in the opening, and the prism is arranged on the side of the infrared first lens close to the infrared second lens.

4. The visible light and infrared dual-mode seeker optical system according to claim 3, characterized in that the lens group includes a visible light first lens, a visible light second lens, and a visible light third lens. The visible light first lens, the visible light second lens, and the visible light third lens are all arranged in the opening, and the visible light first lens, the visible light second lens, and the visible light third lens are arranged in sequence from the along-optical-path fairing to the detector.

5. The visible light and infrared dual-mode seeker optical system according to claim 4, characterized in that the working band of the infrared imaging optical module is 8μm - 12μm, and the field of view angle ≥ 8.8°×7°; the working band of the visible light imaging optical module is 0.45μm - 0.85μm, and the field of view angle ≥ 9.9°×7.9°.

6. An optical system imaging method applied to the visible light and infrared dual-mode seeker optical system according to claim 5, characterized in that the visible light imaging optical module reflects visible light to a visible light detector through the prism for imaging.

Images