Dual-band airborne infrared searching, tracking and imaging optical system

Abstract

A dual-band airborne infrared search tracking imaging optical system comprises: a primary mirror, the surface of which is plated with a reflective film; a through hole is formed along the axis; a light incident surface of the secondary lens group is plated with a light splitting film layer; the focusing side is arranged on the primary mirror; the first light splitting path assembly comprises a first reflex reflector, a long-wave collimating lens group, a long-wave flyback oscillating mirror, a long-wave imaging lens group and a long-wave detector; the first reflex reflector is arranged on one side, far away from the primary mirror, of the secondary lens group; the long-wave collimating lens group is arranged on the side of the primary lens, and the projections of the primary lens and the long-wave collimating lens group do not coincide in the system incident direction; the second light splitting path assembly comprises a medium-wave collimating lens group, a medium-wave flyback oscillating mirror, a medium-wave imaging lens group and a medium-wave detector; the medium wave collimating lens group is arranged on one side, close to the primary lens, of the secondary lens group; and the medium-wave flyback swing mirror, the medium-wave imaging lens group and the medium-wave detector are arranged on the non-focusing side of the primary mirror, so that an imaging light path corresponding to the second light splitting path assembly is arranged on the non-focusing side of the primary mirror. The device is simple in light path and high in transmittance.

Description

Technical Field

[0001] The invention relates to the field of infrared detection technology, and in particular to a dual-band airborne infrared search, tracking and imaging optical system. Background Art

[0002] With the development and maturity of refrigerated infrared detector technology, infrared optical systems are increasingly widely used in various optoelectronic detection equipment. In airborne infrared search and tracking systems, in order to improve the detection distance and recognition capabilities, it is often necessary to increase the amount of light entering the system, so a large-aperture, dual-band infrared optical system is required. The dual-band often uses an infrared band plus a visible light band or a medium-wave infrared band plus a long-wave infrared band. Limited by the detection distance of the visible light band, the optical solution of medium-wave infrared plus long-wave infrared is increasingly valued, but the current medium- and long-wave dual-band infrared detectors are not mature enough. Therefore, the optical solution of medium-wave infrared plus long-wave infrared generally uses medium- and long-wave splitting in the system and using two detectors.

[0003] In traditional airborne long-range infrared search and tracking systems, the optical imaging scheme generally adopts a multi-level optical path combination. The first-level optical path is designed to emit parallel light from the dual-band common optical path telescope optical path, so as to use a plane beam splitter for medium and long wave splitting. Since the platform needs to perform rapid search of the turntable, the system needs to design a secondary optical path to place a retracement mirror for retracement scanning to compensate for the imaging blur caused by rapid search, and finally design a tertiary optical path for imaging design. Therefore, airborne infrared search and tracking optical systems are often more complex, with at least three optical path levels, and are characterized by complex systems, long optical paths, and many lenses. This also leads to the system's transmittance being often relatively low, which has a greater limitation on the system's effective distance. Summary of the invention

[0004] The invention provides a dual-band airborne infrared search and tracking imaging optical system, which solves the problem that the airborne infrared search and tracking system is limited in long-distance detection due to complex optical path and low transmittance.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions: Provided is a dual-band airborne infrared search, tracking and imaging optical system, comprising: The main mirror is configured as a large-aperture parabolic reflector with a reflective film coated on the surface, which is used to focus the incoming light of the system; a through hole is opened along the axis of the main mirror; The secondary lens group is arranged on the focusing side of the primary mirror along the axis of the primary mirror and receives the reflected light of the primary mirror; the light incident surface of the secondary lens group is coated with a medium-wave reflection and long-wave transmission spectroscopic film layer; The first light splitting path component comprises a first folding reflector, a long-wave collimating mirror group, a long-wave retracement mirror, a long-wave imaging lens group and a long-wave detector which are sequentially arranged along the light path direction; the first folding reflector is arranged on the side of the secondary lens group away from the primary mirror; the long-wave collimating mirror group is arranged on the side of the primary mirror, and the projections of the two along the incident light direction of the system do not overlap; The second light splitting path component comprises a medium wave collimating mirror group, a medium wave retrace pendulum mirror, a medium wave imaging lens group and a medium wave detector which are sequentially arranged along the light path direction; the medium wave collimating mirror group is arranged on the side of the secondary lens group close to the primary mirror; the medium wave retrace pendulum mirror, the medium wave imaging lens group and the medium wave detector are arranged on the non-focusing side of the primary mirror, so that the imaging light path corresponding to the second light splitting path component is arranged on the non-focusing side of the primary mirror.

[0006] Furthermore, the secondary lens group has a set optical focal length, and is used to form a first intermediate image plane and a second intermediate image plane between the first folding reflector and the long-wave collimating lens group and between the secondary lens group and the medium-wave collimating lens group, respectively.

[0007] Furthermore, the secondary lens assembly includes a first lens and a second lens having different optical powers and arranged in sequence along the light path, and the incident surface of the first lens is configured as a light splitting surface.

[0008] Furthermore, the long-wave collimating lens group includes two positive power lenses, the materials of which are germanium and zinc selenide respectively.

[0009] Furthermore, the long-wave imaging lens group includes a first long-wave imaging lens, a second long-wave imaging lens and a third long-wave imaging lens which are arranged in sequence along the light path direction, and their materials are germanium, germanium and zinc sulfide respectively, and their surfaces include aspheric surfaces or diffraction surfaces; a second folding reflector is arranged between the second long-wave imaging lens and the third long-wave imaging lens, and the second folding reflector, the third long-wave imaging lens and the long-wave detector are arranged on the non-focusing side of the main mirror.

[0010] Furthermore, the medium wave collimating lens group includes a first medium wave collimating lens, a second medium wave collimating lens and a third medium wave collimating lens which are arranged in sequence along the light path direction, and the materials thereof are silicon, germanium and germanium respectively, and the surfaces thereof include aspheric surfaces or diffraction surfaces; the first medium wave collimating lens is arranged on the focusing side of the main mirror, a third folding reflector is arranged between the first medium wave collimating lens and the second medium wave collimating lens, and the third folding reflector, the second medium wave collimating lens and the third medium wave collimating lens are arranged on the non-focusing side of the main mirror.

[0011] Furthermore, by configuring the aperture relationship between the secondary lens group, the first medium-wave collimating lens and the primary mirror, a structure in which the system incident light blocking rate is ≤1 / 30 is formed.

[0012] Furthermore, the medium-wave imaging lens group includes a first medium-wave imaging lens, a second medium-wave imaging lens, a third medium-wave imaging lens and a fourth medium-wave imaging lens which are arranged in sequence along the light path, and their materials are germanium, germanium, silicon and germanium respectively, and their surfaces include aspherical surfaces or diffraction surfaces; a fourth folding reflector is arranged between the second medium-wave imaging lens and the third medium-wave imaging lens.

[0013] Furthermore, the long-wave imaging lens group and the medium-wave imaging lens group are both configured as a converging imaging optical path having an intermediate image plane.

[0014] Furthermore, the primary mirror, the secondary lens group, the first folding reflector and the long-wave collimating lens group constitute a long-wave telescopic optical path, which has an intermediate image plane. At the long-wave retracement swing mirror, the light is parallel light; the primary mirror, the secondary lens group and the medium-wave collimating lens group constitute a medium-wave telescopic optical path, which has an intermediate image plane. At the medium-wave retracement swing mirror, the light is parallel light.

[0015] The dual-band airborne infrared search and tracking imaging optical system of the present invention has the following beneficial effects: This optical system uses a primary mirror to achieve dual-band, large-aperture and common-aperture incidence, meeting the need to increase the amount of light entering the system in order to increase the detection distance in the airborne infrared search and tracking system; the secondary lens group is used to complete the medium and long-wave splitting, abandoning the traditional airborne long-range infrared search and tracking system that needs to telescope and reduce the incident light, and then add a plane beam splitter in the parallel optical path, thereby simplifying the system, thereby reducing the number of lenses and improving the system transmittance; the secondary lens group has a certain optical focal length for both the reflected optical path and the transmitted optical path, so the primary mirror and the secondary lens group also play a role in the optical path, cooperating with the medium-wave and long-wave collimating mirrors to complete the optical path collimation, and cooperating with the retracement swing mirror to realize the retracement compensation function when the system quickly searches and images; the medium-wave and long-wave imaging optical paths are located on both sides of the secondary lens respectively. Compared with the traditional airborne long-range infrared search and tracking system, under the same technical requirements, the overall length of the system can be shortened, the total weight of the system can be reduced, the system is convenient for compact layout, and it is beneficial to the control of the search and tracking turntable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a dual-band airborne infrared search, tracking and imaging optical system provided in an embodiment of the present application; Figure 2 A schematic structural diagram of another dual-band airborne infrared search, tracking and imaging optical system provided in an embodiment of the present application; Figure 3 A stereoscopic diagram of a dual-band airborne infrared search, tracking and imaging optical system provided in an embodiment of the present application.

[0017] Reference numerals: Main mirror 1; secondary lens group 2; first lens 21; second lens 22; first folding reflector 3; long-wave collimating mirror group 4; long-wave retrace pendulum mirror 5; long-wave imaging lens group 6; first long-wave imaging lens 61, second long-wave imaging lens 62; third long-wave imaging lens 63; long-wave detector 7; medium-wave collimating mirror group 8; first medium-wave collimating lens 81, second medium-wave collimating lens 82; third medium-wave collimating lens 83; medium-wave retrace pendulum mirror 9; medium-wave imaging lens group 10; first medium-wave imaging lens 101; second medium-wave imaging lens 102; third medium-wave imaging lens 103; fourth medium-wave imaging lens 104; medium-wave detector 11; second folding reflector 12; third folding reflector 13; fourth folding reflector 14. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the technical solutions in the embodiments of the present application are clearly described. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0019] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0020] The description of the method flow in the specification of the present application and the steps of the flowchart in the drawings of the present specification do not have to be strictly executed according to the step numbers, and the method steps can be executed in a different order. Moreover, some steps can be omitted, multiple steps can be combined into one step, and / or one step can be decomposed into multiple steps.

[0021] The dual-band airborne infrared search, tracking and imaging optical system provided in the embodiment of the present application is described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0022] In order to solve the problems of complex optical path and low transmittance of dual-band airborne infrared search, tracking and imaging systems, the embodiment of the present application provides a novel dual-band airborne infrared search, tracking and imaging optical system. The optical system eliminates the need for a plane beam splitter and the resulting complex optical path problem in the traditional infrared search and tracking system when splitting light, and by simplifying the system, the system has a higher transmittance, which can further improve the range of the airborne infrared search and tracking system.

[0023] See also Figure 1 and 3 , the embodiment of the present application provides a dual-band airborne infrared search and tracking imaging optical system, such as Figure 1 and 3 As shown, the optical system of the embodiment of the present application includes: The primary mirror 1 is configured as a large-aperture parabolic reflector (generally speaking, an optical system with a light-entry aperture greater than 200 mm can be considered a large-aperture optical system), and a reflective film is coated on the surface to focus the light entering the system; the primary mirror 1 is provided with a through hole along the axis; The secondary lens group 2 is arranged on the focusing side (parabolic side) of the primary mirror 1 along the axis of the primary mirror 1 and receives the reflected light of the primary mirror 1; the light incident surface of the secondary lens group 2 is coated with a medium-wave reflection and long-wave transmission spectroscopic film layer, forming a structure with medium- and long-wave infrared spectroscopic functions; The first light splitting path component comprises a first folding reflector 3, a long-wave collimating mirror group 4, a long-wave retracement mirror 5, a long-wave imaging lens group 6 and a long-wave detector 7 which are sequentially arranged along the light path direction; the first folding reflector 3 is arranged on the side of the secondary lens group 2 away from the primary mirror 1; the long-wave collimating mirror group 4 is arranged on the side of the primary mirror 1, and the projections of the two along the incident light direction of the system do not overlap; The second light splitting path component comprises a medium wave collimating mirror group 8, a medium wave retrace pendulum mirror 9, a medium wave imaging lens group 10 and a medium wave detector 11 which are sequentially arranged along the light path direction; the medium wave collimating mirror group 8 is arranged on the side of the secondary lens group 2 close to the primary mirror 1; the medium wave retrace pendulum mirror 9, the medium wave imaging lens group 10 and the medium wave detector 11 are arranged on the non-focusing side (plane side) of the primary mirror 1, so that the imaging light path corresponding to the second light splitting path component is arranged on the non-focusing side of the primary mirror.

[0024] Furthermore, the secondary lens group 2 has a set optical focal length, and is used to form a first intermediate image plane and a second intermediate image plane respectively between the first folding reflector 3 and the long-wave collimator group 4 and between the secondary lens group 2 and the medium-wave collimator group 8. The main mirror 1, the secondary lens group 2, the first folding reflector 3 and the long-wave collimator group 4 form a long-wave telescopic optical path, with an intermediate image plane, and at the long-wave retracement oscillating mirror 5, the light is parallel light; the main mirror 1, the secondary lens group 2, and the medium-wave collimator group 8 form a medium-wave telescopic optical path, with an intermediate image plane, and at the medium-wave retracement oscillating mirror 9, the light is parallel light.

[0025] The optical path structure is as follows: The light beams in the medium-wave infrared and long-wave infrared bands are incident on the primary mirror 1, which converges the light beams. After the light beams reach the incident surface of the secondary lens group 2, which is also the system's splitting surface, the medium-wave infrared is reflected and the long-wave infrared is transmitted.

[0026] In the long-wave optical path, the light beam transmitted by the secondary lens group 2 is first deflected to the side of the primary mirror 1 (for example, the upper side as shown in the figure) by the first deflecting reflector 3, and the light beam is collimated into parallel light by the long-wave collimating lens group 4. There is an intermediate image plane in the optical path between the first deflecting reflector 3 and the long-wave collimating lens group 4, and the optical path distance is greater than the semi-aperture of the primary mirror 1, so as to avoid blocking the incident light of the system; after being collimated by the long-wave collimating lens group 4, the emergent light is parallel light and reaches the long-wave retrace pendulum mirror 5. When the system is performing a rapid search, the long-wave retrace pendulum mirror 5 can perform imaging compensation by retracement; the light reflected by the long-wave retrace pendulum mirror 5 is finally imaged by the long-wave imaging lens group 6 and converged onto the long-wave detector 7 to form an image.

[0027] In the medium-wave optical path, the light beam reflected by the secondary lens group 2 is collimated by the medium-wave collimator group 8, and parallel light is emitted. There is an intermediate image plane elongated optical path structure between the secondary lens group 2 and the medium-wave collimator group 8, so that the medium-wave imaging optical path is arranged to the non-focusing side of the main mirror 1 (behind the main mirror 1 as shown in the figure), realizing a compact layout of the system. The parallel light is then retrace imaging compensation through the medium-wave retrace pendulum mirror 9, and finally imaged by the medium-wave imaging lens group 10 and converged onto the medium-wave detector 11 to form an image.

[0028] The principle of the present invention is that: on the basis of meeting the technical requirements of large aperture and dual band of airborne infrared search and tracking system, only one primary mirror 1 is used to realize dual band, large aperture and common aperture incidence, so as to ensure the light input of the system; the front surface of the secondary lens group 2 has the function of transmitting long wave and reflecting medium wave, so only the secondary lens group 2 is used to complete the medium and long wave splitting, and the plane beam splitter and the complicated optical path problem caused by the traditional infrared search and tracking system are eliminated when splitting. At the same time, the primary mirror 1 and the secondary lens group 2 are also matched with the medium wave and long wave collimating mirrors in the optical path to realize the parallel optical path (the secondary lens group 2 has a certain optical focal length for the reflected optical path and the transmitted optical path at the same time), so that the retracement swing mirror can be set to realize the system search function, and the imaging lens group can be used to realize the system imaging function. Therefore, the optical scheme greatly reduces the complexity of the system, makes the layout compact, reduces the number of lenses, and improves the system transmittance.

[0029] See also Figure 2In some possible implementations, the secondary lens group 2 includes a first lens 21 and a second lens 22 having different optical powers and arranged in sequence along the optical path, and the incident surface of the first lens 21 is configured as a beam splitting surface. The light beams in the medium-wave infrared and long-wave infrared bands are incident on the primary mirror 1, and the primary mirror 1 converges the light beams. After the light beams reach the incident surface of the first lens group 21, which is also the beam splitting surface of the system, the medium-wave infrared is reflected and the long-wave infrared is transmitted.

[0030] See also Figure 2 Furthermore, the long-wave collimator lens group 4 includes two positive power lenses, the materials of which are germanium and zinc selenide, respectively. A third intermediate image plane can be formed between the two lenses. By designing the intermediate image plane, it is ensured that the optical path distance between the first folding reflector 3 and the long-wave collimator lens group 4 is greater than the semi-aperture of the main mirror 1, so as to avoid blocking the incident light of the system.

[0031] See also Figure 2 Furthermore, the long-wave imaging lens group 6 includes a first long-wave imaging lens 61, a second long-wave imaging lens 62 and a third long-wave imaging lens 63 which are arranged in sequence along the light path direction, and the materials thereof are germanium, germanium and zinc sulfide, respectively, and the surfaces thereof include aspheric surfaces or diffraction surfaces; a second folding reflector 12 is arranged between the second long-wave imaging lens 62 and the third long-wave imaging lens 63, and the second folding reflector 12, the third long-wave imaging lens 63 and the long-wave detector 7 are arranged on the non-focusing side of the main mirror 1 to change the light path direction to form a compact layout.

[0032] See also Figure 2 Further, the medium wave collimating lens group 8 includes a first medium wave collimating lens 81, a second medium wave collimating lens 82 and a third medium wave collimating lens 83 which are sequentially arranged along the optical path direction, and the materials thereof are silicon, germanium and germanium respectively, and the surfaces thereof include aspheric surfaces or diffraction surfaces; the first medium wave collimating lens 81 is arranged on the focusing side of the primary mirror 1, and a third folding reflector 13 is arranged between the first medium wave collimating lens 81 and the second medium wave collimating lens 82, and the third folding reflector 13, the second medium wave collimating lens 82 and the third medium wave collimating lens 83 are arranged on the non-focusing side of the primary mirror 1. There is an intermediate image plane elongated optical path structure between the secondary lens group 2 and the medium wave collimating lens group 8, so that the third folding reflector 13 is inserted to arrange the medium wave imaging optical path behind the primary mirror, so as to realize a compact layout of the system, and the parallel light is then subjected to the medium wave retracement imaging compensation by the medium wave retracement swing mirror 9, and finally the medium wave imaging lens group 10 is imaged and converged to the medium wave detector 11 to form an image.

[0033] Furthermore, by configuring the aperture relationship between the secondary lens group 2, the first medium-wave collimating lens 81 and the primary mirror 1, a structure in which the system incident light blocking rate is ≤1 / 30 is formed.

[0034] See also Figure 2Furthermore, the medium wave imaging lens group 10 includes a first medium wave imaging lens 101, a second medium wave imaging lens 102, a third medium wave imaging lens 103 and a fourth medium wave imaging lens 104 which are arranged in sequence along the light path direction, and the materials thereof are germanium, germanium, silicon and germanium respectively, and the surfaces thereof include aspherical surfaces or diffraction surfaces; a fourth folding reflector 14 is arranged between the second medium wave imaging lens 102 and the third medium wave imaging lens 103 to change the light path direction to form a compact layout.

[0035] Furthermore, the long-wave imaging lens group 6 and the medium-wave imaging lens group 10 are both configured as a convergent imaging optical path with an intermediate image plane. The design can meet the 100% cold aperture efficiency of the cooling optical system for the cooling infrared detector required by the system, while ensuring the minimization of the retracement mirror and the system optical path aperture.

[0036] In the specific implementation process of the embodiment of the present application, the reflective film of the primary mirror 1 can be a gold film, a silver film, etc.; the primary mirror 1 is also fixedly connected to the external frame of the device through a substrate component; the substrate material is a metal material, for example, the substrate material can be an aluminum alloy, which has sufficient strength and hardness, and can also maintain the same thermal stress as the external frame, avoiding the lens stress and deformation caused by temperature changes or temperature shocks. The material of the secondary lens group 2 can be germanium, zinc selenide or zinc sulfide. In the design process, by controlling the aperture of the secondary lens, the shielding rate is ≤1 / 30 (area ratio) to ensure the incident light energy of the system. The materials of the long-wave collimator group 4 and the long-wave imaging lens group 6 can be germanium, zinc selenide or zinc sulfide. The materials of the medium-wave collimator group 8 and the medium-wave imaging lens group 10 can be silicon, germanium, zinc selenide or zinc sulfide. The long-wave detector 7 and the medium-wave detector 11 can be configured as refrigerated detectors. The above-mentioned retracement mirrors (5 and 9) and the folding reflectors (3, 12, 13 and 14) can be set at a 45° angle in the optical path.

[0037] Advantages of the present invention: 1) The optical system of the present invention has a dual operating band of medium-wave infrared 3.7μm-4.8μm and long-wave infrared 7.3μm-10.5μm, which meets the technical requirements of airborne long-range infrared search and tracking systems to improve target recognition capabilities; 2) The optical system of the present invention uses a primary mirror 1, which realizes dual-band, large-aperture and common-aperture incidence, and the light-through aperture can be greater than Φ200mm, meeting the need to increase the amount of light entering the system in order to increase the detection distance in the airborne infrared search and tracking system; 3) The optical system of the present invention uses the secondary lens 2 to complete the medium and long wave splitting, abandoning the solution of the traditional airborne long-distance infrared search and tracking system that needs to telescope the incident light and then add a plane beam splitter in the parallel light path, thereby simplifying the system; 4) The secondary lens 2 of the present invention has a certain optical focal length for both the reflected light path and the transmitted light path. Therefore, the primary mirror 1 and the secondary lens 2 also play a role in the optical path in conjunction with the medium-wave and long-wave collimating mirrors to complete the optical path collimation, and in conjunction with the retrace oscillating mirror to achieve the retrace compensation function when the system quickly searches for imaging; 5) By controlling the aperture of the secondary lens 2, the light path obstruction is reduced to achieve an obstruction rate of ≤1 / 30; 6) The medium-wave and long-wave imaging optical paths are located on both sides of the secondary lens, and both adopt an optical path structure with two intermediate image planes, which facilitates the compact layout of the system and is conducive to the control of the search and tracking turntable; 7) The medium-wave and long-wave imaging optical paths are located on both sides of the secondary lens. Compared with the traditional airborne long-range infrared search and tracking system, the overall length and weight of the system can be shortened under the same technical requirements; 8) The non-plane beam splitter feature of the optical system of the present invention and the optical path simplification effect it brings can reduce the number of lenses and improve the system transmittance.

[0038] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0039] It can be understood that the embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive, and those skilled in the art are aware that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, those of ordinary skill in the art can modify these features and embodiments to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention under the inspiration or teaching of the present application. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope protected by the present invention.

Claims

1. Dual-band airborne infrared search, tracking and imaging optical system, characterized in that: include: The main mirror is configured as a large-aperture parabolic reflector with a reflective film coated on the surface, which is used to focus the incoming light of the system; a through hole is opened along the axis of the main mirror; The secondary lens group is arranged on the focusing side of the primary mirror along the axis of the primary mirror and receives the reflected light of the primary mirror; the light incident surface of the secondary lens group is coated with a medium-wave reflection and long-wave transmission spectroscopic film layer; The first light splitting path component comprises a first folding reflector, a long-wave collimating mirror group, a long-wave retracement mirror, a long-wave imaging lens group and a long-wave detector which are sequentially arranged along the light path direction; the first folding reflector is arranged on the side of the secondary lens group away from the primary mirror; the long-wave collimating mirror group is arranged on the side of the primary mirror, and the projections of the two along the incident light direction of the system do not overlap; The second light splitting path component comprises a medium wave collimating mirror group, a medium wave retrace pendulum mirror, a medium wave imaging lens group and a medium wave detector which are sequentially arranged along the light path direction; the medium wave collimating mirror group is arranged on the side of the secondary lens group close to the primary mirror; the medium wave retrace pendulum mirror, the medium wave imaging lens group and the medium wave detector are arranged on the non-focusing side of the primary mirror, so that the imaging light path corresponding to the second light splitting path component is arranged on the non-focusing side of the primary mirror.

2. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The secondary lens group has a set optical focal length and is used to form a first intermediate image plane and a second intermediate image plane between the first folding reflector and the long-wave collimator group and between the secondary lens group and the medium-wave collimator group respectively.

3. The dual-band airborne infrared search, tracking and imaging optical system according to claim 2, characterized in that: The secondary lens assembly comprises a first lens and a second lens having different optical powers and arranged in sequence along the light path, and the incident surface of the first lens is configured as a light splitting surface.

4. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The long-wave collimator lens group includes two positive-power lenses, the materials of which are germanium and zinc selenide respectively.

5. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The long-wave imaging lens group includes a first long-wave imaging lens, a second long-wave imaging lens and a third long-wave imaging lens which are arranged in sequence along the light path, and the materials of the lenses are germanium, germanium and zinc sulfide respectively, and the surfaces of the lenses include aspheric surfaces or diffraction surfaces; a second folding reflector is arranged between the second long-wave imaging lens and the third long-wave imaging lens, and the second folding reflector, the third long-wave imaging lens and the long-wave detector are arranged on the non-focusing side of the primary mirror.

6. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The medium wave collimating lens group comprises a first medium wave collimating lens, a second medium wave collimating lens and a third medium wave collimating lens which are sequentially arranged along the light path direction, and the materials thereof are respectively silicon, germanium and germanium, and the surfaces thereof comprise aspheric surfaces or diffraction surfaces; the first medium wave collimating lens is arranged on the focusing side of the main mirror, a third folding reflector is arranged between the first medium wave collimating lens and the second medium wave collimating lens, and the third folding reflector, the second medium wave collimating lens and the third medium wave collimating lens are arranged on the non-focusing side of the main mirror.

7. The dual-band airborne infrared search, tracking and imaging optical system according to claim 6, characterized in that: By configuring the aperture relationship between the secondary lens group, the first medium-wave collimating lens and the primary mirror, a structure in which the system incident light blocking rate is ≤1 / 30 is formed.

8. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The medium wave imaging lens group includes a first medium wave imaging lens, a second medium wave imaging lens, a third medium wave imaging lens and a fourth medium wave imaging lens which are arranged in sequence along the light path direction, and the materials thereof are germanium, germanium, silicon and germanium respectively, and the surfaces thereof include aspherical surfaces or diffraction surfaces; a fourth folding reflector is arranged between the second medium wave imaging lens and the third medium wave imaging lens.

9. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The long-wave imaging lens group and the medium-wave imaging lens group are both configured as a converging imaging optical path with an intermediate image plane.

10. The dual-band airborne infrared search, tracking and imaging optical system according to claim 1, characterized in that: The primary mirror, secondary lens group, first folding reflector and long-wave collimator group form a long-wave telephoto optical path with an intermediate image plane. At the long-wave retracement swing mirror, the light is parallel light. The primary mirror, secondary lens group and medium-wave collimator group form a medium-wave telephoto optical path with an intermediate image plane. At the medium-wave retracement swing mirror, the light is parallel light.

Images