High-performance visible light-long wave infrared two-in-one optical system

Abstract

The invention discloses a high-performance visible light-long wave infrared two-in-one optical system which mainly solves the problems that a traditional independent visible light system and a traditional independent infrared band optical system are large in size and weight and the like. The optical system comprises a main reflector, a spectrum light splitting element, a visible light continuous zooming optical module and a long-wave infrared optical module. A light beam from a target object is reflected by the main reflector to reach the spectrum light splitting element and then is divided into two paths, one path is reflected to enter the visible light continuous zooming optical module, and the other path is transmitted to enter the long-wave infrared optical module; the main reflecting mirror, the spectrum light splitting element and the visible light continuous zooming optical module jointly form a visible light continuous zooming optical system to receive visible light in the light beam; the main reflector, the spectrum light splitting element and the long-wave infrared optical module jointly form a long-wave infrared optical system to receive long-wave infrared light in the light beam. The optical system can meet the requirements for long-distance high-sensitivity detection and medium-short distance high-resolution high-contrast imaging of a target.

Description

Technical Field

[0001] The present invention relates to a multi-spectral optoelectronic imaging system, and in particular to a high-performance visible light-long-wave infrared two-in-one optical system, and in particular to a multi-spectral integrated optical system suitable for close-range high-resolution, high-contrast imaging and long-range high-sensitivity detection in a ground target range. Background Art

[0002] With the continuous development of optoelectronic technology, the demand for high-resolution, high-contrast imaging of the key processes in the initial stage of the target range measurement mission and high-sensitivity detection at long distances is becoming more and more urgent. At the same time, in order to meet the requirements of all-day combat, multiple bands need to be used to obtain information about the target. Therefore, the traditional single visible light band can no longer meet the application requirements. At present, the commonly used method is to use visible light systems and infrared band systems to obtain information together. Among them, the visible light system mainly relies on the sunlight reflected by the target for imaging, with high resolution and rich details, but it is greatly affected by the weather, especially under conditions of poor visibility such as haze, and it is easy to lose combat effectiveness. The infrared band system mainly relies on the target's own radiation for detection and imaging, is less affected by the weather, can work all day, and has the advantages of high-contrast imaging and high-sensitivity detection.

[0003] However, as the detection and imaging distance increases, the aperture of each system is also increasing. The traditional two independent imaging systems have exposed the shortcomings of large size and heavy weight, which is not conducive to the miniaturization and lightweight development of the system. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problem of large volume and weight of traditional independent visible light system and infrared band optical system, and to provide a high-performance visible light-long wave infrared two-in-one optical system.

[0005] In order to achieve the above objectives, the technical solutions provided by the present invention are as follows:

[0006] A high-performance visible light-long-wave infrared two-in-one optical system, which is special in that:

[0007] It includes a main reflector, a spectral spectrometer, a visible light continuous zoom optical module, and a long-wave infrared optical module;

[0008] The spectral beam splitter is located on the reflection light path of the main reflector. The light beam from the target object is reflected by the main reflector and reaches the spectral beam splitter, and is divided into two paths. One path is reflected by the spectral beam splitter and enters the visible light continuous zoom optical module, and the other path is transmitted by the spectral beam splitter and enters the long-wave infrared optical module.

[0009] The main reflector, the spectrum splitting element and the visible light continuous zoom optical module together constitute a visible light continuous zoom optical system for receiving visible light in the light beam;

[0010] The main reflector, the spectral splitter element and the long-wave infrared optical module together constitute a long-wave infrared optical system for receiving the long-wave infrared light in the light beam.

[0011] Furthermore, the visible light continuous zoom optical module comprises a first folding mirror, a correction mirror group, a second folding mirror and a visible light continuous zoom mirror group which are sequentially arranged along the reflection light path of the spectrum splitting element; wherein the first folding mirror and the second folding mirror are respectively used for turning the light path;

[0012] The correction lens group comprises a first correction lens, a second correction lens and a third correction lens arranged in sequence along the optical path; wherein the first correction lens is a meniscus heavy flint lens with negative focal length convex toward the object side; the second correction lens is a meniscus heavy phosphorus crown glass with positive focal length convex toward the image side; and the third correction lens is a meniscus light crown lens with positive focal length convex toward the image side.

[0013] The visible light continuous zoom lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a first cemented lens, a second cemented lens, a tenth lens, a third cemented lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens, which are sequentially arranged along the optical path; by adjusting the positions of the fifth lens, the first cemented lens, the second cemented lens, and the tenth lens along the optical axis, the visible light continuous zoom is achieved, wherein the fifth lens and the first cemented lens form a variable magnification lens group, which moves along the optical axis toward the image plane, and the second cemented lens and the tenth lens form a compensation lens group, which moves along the optical axis toward the object plane;

[0014] The first lens is a plano-convex heavy flint lens with positive optical power;

[0015] The second lens is a negative power biconcave heavy flint lens;

[0016] The third lens is a biconvex fluor crown lens with positive optical power;

[0017] The fourth lens is a biconvex fluor crown lens with positive optical power;

[0018] The fifth lens is a meniscus heavy flint lens with positive refractive power and convex toward the object side;

[0019] The first cemented lens is a double concave cemented lens with negative focal power, which is formed by cementing a sixth lens and a seventh lens, wherein the sixth lens is arranged close to the fifth lens and is a meniscus heavy flint lens with positive focal power convex toward the image side, and the seventh lens is a heavy flint lens with negative focal power and double concave;

[0020] The second cemented lens is a biconvex cemented lens with positive focal power, which is formed by cementing an eighth lens and a ninth lens, wherein the eighth lens is arranged close to the seventh lens and is a meniscus heavy lanthanum flint lens with negative focal power convex toward the object side, and the ninth lens is a biconvex lanthanum crown lens with positive focal power;

[0021] The tenth lens is a biconvex crystal lens with positive optical power;

[0022] The third cemented lens is a biconvex cemented lens with positive focal power, which is formed by cementing an eleventh lens and a twelfth lens, wherein the eleventh lens is arranged close to the tenth lens and is a meniscus lanthanum flint lens with negative focal power convex toward the object side, and the twelfth lens is a heavy flint lens with positive focal power and biconvex;

[0023] The thirteenth lens is a double concave heavy flint lens with negative optical power;

[0024] The fourteenth lens is a meniscus heavy flint lens with positive refractive power and convex toward the image side;

[0025] The fifteenth lens is a meniscus heavy lanthanum flint lens with positive refractive power and convex toward the object side.

[0026] Further, the thickness of the first correction mirror is 25.54 mm, the radius of curvature of the front surface is 101.33 mm, and the radius of curvature of the rear surface is 74.42 mm;

[0027] The thickness of the second correction mirror is 14.00 mm, the radius of curvature of the front surface is -400.56 mm, and the radius of curvature of the rear surface is -181.49 mm;

[0028] The thickness of the third correction mirror is 19.99 mm, the radius of curvature of the front surface is -56.91 mm, and the radius of curvature of the rear surface is -61.7 mm;

[0029] The thickness of the first lens is 15.00 mm, the front surface is a plane, and the radius of curvature of the rear surface is -163.00 mm;

[0030] The thickness of the second lens is 6.00 mm, the radius of curvature of the front surface is -154.10 mm, and the radius of curvature of the rear surface is 108.00 mm;

[0031] The thickness of the third lens is 18.38 mm, the radius of curvature of the front surface is 172.92 mm, and the radius of curvature of the rear surface is -192.49 mm;

[0032] The thickness of the fourth lens is 17.81 mm, the radius of curvature of the front surface is 110.70 mm, and the radius of curvature of the rear surface is -9546.83 mm;

[0033] The fifth lens has a thickness of 19.79 mm, a radius of curvature of the front surface of 88.77 mm, and a radius of curvature of the rear surface of 113.28 mm;

[0034] The thickness of the sixth lens is 19.56 mm, the radius of curvature of the front surface is -356.66 mm, and the radius of curvature of the rear surface is -74.28 mm;

[0035] The thickness of the seventh lens is 15.08 mm, the radius of curvature of the front surface is -74.28 mm, and the radius of curvature of the rear surface is 87.29 mm;

[0036] The eighth lens has a thickness of 6.20 mm, a radius of curvature of the front surface of 19581.11 mm, and a radius of curvature of the rear surface of 80.32 mm;

[0037] The thickness of the ninth lens is 11.11 mm, the radius of curvature of the front surface is 80.32 mm, and the radius of curvature of the rear surface is -121.49 mm;

[0038] The thickness of the tenth lens is 9.42 mm, the radius of curvature of the front surface is 88.98 mm, and the radius of curvature of the rear surface is -187.54 mm;

[0039] The thickness of the eleventh lens is 5.45 mm, the radius of curvature of the front surface is 296.82 mm, and the radius of curvature of the rear surface is 36.94 mm;

[0040] The thickness of the twelfth lens is 25.00 mm, the radius of curvature of the front surface is 36.94 mm, and the radius of curvature of the rear surface is -947.764 mm;

[0041] The thirteenth lens has a thickness of 25.00 mm, a curvature radius of the front surface of -83.082 mm, and a curvature radius of the rear surface of 535.35 mm;

[0042] The thickness of the fourteenth lens is 5.47 mm, the radius of curvature of the front surface is -78.858 mm, and the radius of curvature of the rear surface is -54.565 mm;

[0043] The thickness of the fifteenth lens is 25.00 mm, the radius of curvature of the front surface is 54.217 mm, and the radius of curvature of the rear surface is 46.998 mm.

[0044] Furthermore, the long-wave infrared optical module comprises a third folding mirror, a fourth folding mirror, a fifth folding mirror and a long-wave infrared projection mirror group which are sequentially arranged along the transmission light path of the spectrum splitting element; wherein the third folding mirror, the fourth folding mirror and the fifth folding mirror are respectively used for turning the light path;

[0045] The long-wave infrared projection mirror group comprises a first long-wave mirror, a second long-wave mirror, a third long-wave mirror, and a fourth long-wave mirror arranged in sequence along the optical path;

[0046] The first long-wave mirror is a meniscus germanium lens with positive focal power and convex toward the object side;

[0047] The second long-wave mirror is a meniscus germanium lens with negative optical power and convex toward the image side;

[0048] The third long-wave mirror is a meniscus ZnS lens with negative optical power and convex toward the image side;

[0049] The fourth long-wave mirror is a meniscus germanium lens with positive optical power and convex toward the object side.

[0050] Furthermore, a compensation mirror is provided at the light incident end of the first long-wave mirror for detecting the long-wave infrared projection mirror group, wherein the compensation mirror is a meniscus germanium lens with negative optical power convex toward the object side.

[0051] Further, the thickness of the first long-wave mirror is 10.00 mm, the radius of curvature of the front surface is 106.1128 mm, and the radius of curvature of the rear surface is 355.04 mm;

[0052] The second long-wave mirror has a thickness of 8.00 mm, a front surface that is aspherical, a vertex curvature radius of -117.498 mm, and a rear surface that has a curvature radius of -147.996 mm;

[0053] The thickness of the third long-wave mirror is 20.00 mm, the radius of curvature of the front surface is -27.84 mm, and the radius of curvature of the rear surface is -42.642 mm;

[0054] The fourth long-wave mirror has a thickness of 5.00 mm, a radius of curvature of the front surface of 64.325 mm, and a radius of curvature of the rear surface of 120.0 mm;

[0055] The thickness of the compensation mirror is 9.16 mm, the curvature radius of the front surface is 498.85 mm, and the rear surface is an aspherical surface with a vertex curvature radius of 163.00 mm.

[0056] Furthermore, the main reflector is a hyperbolic surface, the vertex curvature radius of which is -1809.3 mm, and the quadratic constant k 1 =-1.04; the spectral splitter element is a positive focal length meniscus hyperbolic germanium lens convex toward the object side, with a thickness of 20.00 mm, a vertex curvature radius of the front surface of -815.451 mm, and a quadratic curve constant k 2 =-3.555; the vertex curvature radius of the rear surface is -526.94mm, and the quadratic curve constant k 2 =-1.9.

[0057] Furthermore, the aperture of the visible light continuous zoom optical system is 400 mm, the focal length is 1500 mm to 3000 mm, the relative aperture is 1 / 3.75 to 1 / 7.5, and the field of view is 0.42° to 0.84°;

[0058] The long-wave infrared optical system has an aperture of 400 mm, a focal length of 800 mm, a relative aperture of 1 / 2, and a field of view of 0.44°.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1. The present invention includes a main reflector, a spectral spectrometer, a visible light continuous zoom optical module, and a long-wave infrared optical module, wherein the main reflector, the spectral spectrometer and the visible light continuous zoom optical module together constitute a visible light continuous zoom optical system for receiving visible light in a light beam; the main reflector, the spectral spectrometer and the long-wave infrared optical module together constitute a long-wave infrared optical system for receiving long-wave infrared light in a light beam. The present invention uses a spectral spectrometer to divide the light beam from the target object into two paths by sharing the main reflector and the spectral spectrometer, and the spectral spectrometer is used to enter the visible light continuous zoom subsystem and the long-wave infrared subsystem respectively, so as to realize synchronous imaging of the two-path system. The system design and layout adopt the idea of ​​miniaturization and modularization, and the common aperture design realizes the characteristic of no parallax in close-range imaging. At the same time, the dual-band optical system has excellent imaging quality and highly sensitive detection performance, which fully meets the system's requirements for high-sensitivity detection of targets at long distances and high-resolution and high-contrast imaging at medium and short distances.

[0061] 2. The visible light continuous zoom optical module of the present invention includes a first folding mirror, a correction mirror group, a second folding mirror and a visible light continuous zoom lens group which are sequentially arranged along the optical path. It adopts a modular design concept, and each module can be assembled and tested independently, which reduces the difficulty of assembly, improves the imaging performance, and shortens the assembly cycle.

[0062] 3. The visible light continuous zoom optical system of the present invention adopts mechanical compensation continuous zoom, and realizes visible light continuous zoom by adjusting the positions of the variable magnification lens group and the compensation lens group along the optical axis, thereby enhancing the applicability and flexibility of the system.

[0063] 4. The long-wave infrared optical system of the present invention adopts a secondary imaging structure, and realizes the conjugation of the system exit pupil and the main mirror size and the matching of the exit pupil and the detector cold screen through the long-wave infrared projection mirror group, thereby reducing the system's own radiation. By setting a horizontal fourth folding axis mirror, the problem of mutual interference between the long-wave infrared and visible light systems is solved from the layout, and it is more manufacturable in focusing and camera installation.

[0064] 5. This system aims to solve the problem that the large-aperture long-wave infrared system process cannot be inspected. By adding a compensation mirror in front of the long-wave infrared projection lens group, the performance of the long-wave infrared projection lens group is guaranteed, while also ensuring the overall performance of the long-wave infrared system.

[0065] 6. The present invention adopts a spectral beam splitting element using a meniscus-shaped hyperbolic germanium lens with positive focal length convex toward the object side, replacing the traditional parallel plate beam splitting method, thereby avoiding the astigmatism and ghost image problems introduced by the flat plate beam splitter.

[0066] 7. The present invention greatly shortens the longitudinal dimension of the system and reduces the rotation radius of the system by adding the first folding mirror, the second folding mirror, the third folding mirror, the fourth folding mirror and the fifth folding mirror in the optical path. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 1 is a light path diagram of a visible light continuous zoom telephoto 3000mm optical system in an embodiment of the present invention.

[0068] Figure 2 1 is an optical path diagram of a visible light continuous zoom short-focus 1500mm optical system in an embodiment of the present invention.

[0069] Figure 3 Schematic diagram of the optical path of the long-wave infrared optical system in an embodiment of the present invention.

[0070] Figure 4 The optical path diagram of the long-wave infrared projection lens group with a compensation mirror added in the embodiment of the present invention.

[0071] Figure 5 This is an MTF curve diagram of an optical system with a spatial frequency of 50lp / mm and a visible light continuous zoom telephoto of 3000mm in an embodiment of the present invention.

[0072] Figure 6 This is an MTF curve diagram of an optical system with a spatial frequency of 50lp / mm and a visible light continuous zoom short focal length of 1500mm in an embodiment of the present invention.

[0073] Figure 7 This is an MTF curve diagram of the optical system with a spatial frequency of 33lp / mm and a long-wave infrared focal length of 800mm in an embodiment of the present invention.

[0074] Figure 8 This is an MTF curve diagram of the optical system with a spatial frequency of 33lp / mm and a long-wave infrared compensation detection optical path in an embodiment of the present invention.

[0075] Fig. 9 Graphs showing spherical aberration, field curvature and distortion of an optical system with a visible light continuous zoom and a telephoto focal length of 3000 mm in an embodiment of the present invention.

[0076] Fig.10 Graphs showing spherical aberration, field curvature and distortion of an optical system with a short-focus of 1500mm for visible light continuous zoom in an embodiment of the present invention.

[0077] Fig.11 The spherical aberration, field curvature and distortion curves of the optical system with a long-wave infrared focal length of 800 mm in the embodiment of the present invention are shown in FIG.

[0078] The reference numerals are as follows:

[0079] 1-main reflecting mirror, 2-spectral spectrometer, 3-first folding mirror, 4-second folding mirror, 5-first correction mirror, 6-second correction mirror, 7-third correction mirror, 8-first lens, 9-second lens, 10-third lens, 11-fourth lens, 12-fifth lens, 13-first cemented mirror, 131-sixth lens, 132-seventh lens, 14-second cemented mirror, 141-eighth lens, 142-ninth lens, 15-tenth lens, 16-third cemented mirror, 161-eleventh lens, 162-twelfth lens, 17-thirteenth lens, 18-fourteenth lens, 19-fifteenth lens, 20-third folding mirror, 21-fourth folding mirror, 22-fifth folding mirror, 23-first long-wave mirror, 24-second long-wave mirror, 25-third long-wave mirror, 26-fourth long-wave mirror, 27-compensation mirror. DETAILED DESCRIPTION

[0080] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth", "thirteenth", "fourteenth", "fifteenth", etc. are used for descriptive purposes only and do not imply their relative importance.

[0081] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 This embodiment provides a high-performance visible light-long-wave infrared two-in-one optical system, including a main reflector 1, a spectral splitting element 2, a visible light continuous zoom optical module, and a long-wave infrared optical module.

[0082] The spectral spectrometer 2 is located on the reflected light path of the main reflector 1. The light beam from the target object is reflected by the main reflector 1 and reaches the spectral spectrometer 2 and is divided into two paths. One path is reflected by the spectral spectrometer 2 and enters the visible light continuous zoom optical module, and the other path is transmitted by the spectral spectrometer 2 and enters the long-wave infrared optical module.

[0083] The main reflector 1, the spectral spectrometer 2 and the visible light continuous zoom optical module of this embodiment together constitute a visible light continuous zoom optical system for receiving visible light in a light beam. The visible light continuous zoom optical system has an aperture of 400mm, a focal length of 1500mm to 3000mm, a relative aperture of 1 / 3.75 to 1 / 7.5, and a field of view of 0.42° to 0.84°. The main reflector 1, the spectral spectrometer 2 and the long-wave infrared optical module together constitute a long-wave infrared optical system for receiving long-wave infrared light in a light beam. The long-wave infrared optical system has an aperture of 400mm, a focal length of 800mm, a relative aperture of 1 / 2, and a field of view of 0.44°. The high-performance visible light-long-wave infrared two-in-one optical system of the present invention has the characteristics of compact layout, small turning radius, and high detection and imaging performance. It is an optical system that satisfies the mutual compensation of high visible light resolution and high infrared contrast and high sensitivity detection.

[0084] The main reflector 1 is a hyperbolic surface, which is beneficial for aberration correction. The spectral beam splitter 2 is a meniscus germanium lens with positive focal power and convex toward the object side. The beam splitting surface and the rear surface are both hyperbolic surfaces. It is both a secondary reflector of the visible light continuous zoom optical system and a correction mirror of the long-wave infrared optical system. The optical parameters of the spectral beam splitter 2 are shown in Table 1.

[0085] Reference Figure 1 and Figure 2 The visible light continuous zoom optical module includes a first folding mirror 3, a correction mirror group, a second folding mirror 4 and a visible light continuous zoom mirror group which are sequentially arranged along the reflection light path of the spectral splitting element 2; wherein the first folding mirror 3 and the second folding mirror 4 are respectively used for turning the light path.

[0086] The correction lens group includes a first correction lens 5, a second correction lens 6 and a third correction lens 7 which are sequentially arranged along the optical path; wherein the first correction lens 5 is a meniscus heavy flint lens with negative optical power convex toward the object side; the second correction lens 6 is a meniscus heavy phosphorus crown glass with positive optical power convex toward the image side; the third correction lens 7 is a meniscus light crown lens with positive optical power convex toward the image side. The optical parameters of each lens are shown in Table 1.

[0087] The visible light continuous zoom lens group includes a first lens 8, a second lens 9, a third lens 10, a fourth lens 11, a fifth lens 12, a first cemented lens 13, a second cemented lens 14, a tenth lens 15, a third cemented lens 16, a thirteenth lens 17, a fourteenth lens 18, and a fifteenth lens 19, which are sequentially arranged along the optical path. By adjusting the positions of the fifth lens 12, the first cemented lens 13, the second cemented lens 14, and the tenth lens 15 along the optical axis, the visible light continuous zoom is realized, wherein the fifth lens 12 and the first cemented lens 13 form a variable magnification lens group, which moves along the optical axis toward the image plane, and the second cemented lens 14 and the tenth lens 15 form a compensation lens group, which moves along the optical axis toward the object plane.

[0088] The first lens 8 is a plano-convex heavy flint lens with positive focal power; the second lens 9 is a biconcave heavy flint lens with negative focal power; the third lens 10 is a biconvex fluorine crown lens with positive focal power; the fourth lens 11 is a biconvex fluorine crown lens with positive focal power; the fifth lens 12 is a meniscus heavy flint lens with positive focal power convex toward the object side; the first cemented lens 13 is a biconcave cemented lens with negative focal power, which is formed by cementing a sixth lens 131 and a seventh lens 132, wherein the sixth lens 131 is arranged close to the fifth lens 12, which is a meniscus heavy flint lens with positive focal power convex toward the image side, and the seventh lens 132 is a biconcave heavy flint lens with negative focal power; the second cemented lens 14 is a biconvex cemented lens with positive focal power, which is cemented by an eighth lens 141 and a ninth lens 142, wherein the eighth lens 141 is close to the first The seventh lens 132 is arranged, which is a meniscus heavy lanthanum flint lens with negative focal power convex toward the object side, the ninth lens 142 is a lanthanum crown lens with positive focal power and double convex; the tenth lens 15 is a crystal lens with positive focal power and double convex; the third cemented lens 16 is a double convex cemented lens with positive focal power, which is formed by cementing an eleventh lens 161 and a twelfth lens 162, wherein the eleventh lens 161 is arranged close to the tenth lens 15, which is a meniscus lanthanum flint lens with negative focal power convex toward the object side, and the twelfth lens 162 is a heavy flint lens with positive focal power and double convex; the thirteenth lens 17 is a heavy flint lens with negative focal power and double concave; the fourteenth lens 18 is a meniscus heavy flint lens with positive focal power convex toward the image side; the fifteenth lens 19 is a meniscus heavy lanthanum flint lens with positive focal power convex toward the object side, and the optical parameters of each lens are shown in Table 1.

[0089] The long-wave infrared optical module includes a third folding mirror 20, a fourth folding mirror 21, a fifth folding mirror 22 and a long-wave infrared projection mirror group which are arranged in sequence along the transmission light path of the spectral splitter element 2; wherein the third folding mirror 20, the fourth folding mirror 21 and the fifth folding mirror 22 are respectively used to turn the light path, thereby reducing the radial and lateral dimensions of the system.

[0090] The long-wave infrared projection lens group includes a first long-wave mirror 23, a second long-wave mirror 24, a third long-wave mirror 25, and a fourth long-wave mirror 26, which are sequentially arranged along the optical path. Among them, the first long-wave mirror 23 is a meniscus germanium lens with positive focal length convex toward the object side; the second long-wave mirror 24 is a meniscus germanium lens with negative focal length convex toward the image side; the third long-wave mirror 25 is a meniscus ZnS lens with negative focal length convex toward the image side; the fourth long-wave mirror 26 is a meniscus germanium lens with positive focal length convex toward the object side. The optical parameters of each lens are shown in Table 1.

[0091] In view of the problem that the large-aperture long-wave infrared system process cannot be inspected, this embodiment adds a compensation mirror 27 in front of the long-wave infrared projection lens group, which is used to detect the long-wave infrared projection lens group, and ensures the performance of the long-wave infrared projection lens group while also ensuring the overall performance of the long-wave infrared system. The compensation mirror 27 is a meniscus germanium lens with negative optical power convex toward the object side, with a thickness of 9.16 mm, a front surface curvature radius of 498.85 mm, and a rear surface aspherical, with a vertex curvature radius of 163.00 mm. Other parameters are shown in Table 1.

[0092] Table 1 Optical parameters of each lens (unit: mm)

[0093]

[0094]

[0095]

[0096] In the table, the aspheric surface is an even-order sphere, and the aspheric surface equation is:

[0097]

[0098] Wherein, z is the z coordinate of the aspheric surface sagittal height, in mm;

[0099] r——radial distance, unit: mm,

[0100] c——corresponding to the radius of curvature;

[0101] k——conic constant;

[0102] A——r 4 Term coefficient;

[0103] B——r 6 Term coefficient;

[0104] C——r 8 Item coefficient.

[0105] The visible light system of this embodiment is applicable to visible light detectors with a resolution of 1920×1080, a pixel pitch of 10μm×10μm, or a target diagonal size less than or equal to 22.02mm. The refrigerated long-wave infrared optical system is applicable to refrigerated long-wave infrared thermal imagers with a resolution of 640×512, a pixel pitch of 15μm×15μm, or a target diagonal size less than or equal to 12.3mm, and a cold screen F number of F2.

[0106] Figure 1 The figure shows the optical path diagram of the visible light continuous zoom telephoto 3000mm optical system. Figure 2The figure shows the optical path diagram of the visible light continuous zoom short-focus 1500mm optical system. The visible light continuous zoom system has an aperture of 400mm, a system focal length of 1500mm to 3000mm continuous zoom, a relative aperture of 1 / 3.75 to 1 / 7.5, and a field of view of 0.42° to 0.84°.

[0107] Figure 3 The figure shows the optical path of the long-wave infrared focal length 800mm optical system. The focal length of the long-wave infrared system is 800mm, the relative aperture is 1 / 2, and the field of view is 0.44°. The visible light system and the long-wave infrared system share the main reflector 1 and the spectral beam splitter 2. A special spectral beam splitter film is plated on the surface of the spectral beam splitter 2 to divide the optical path into two paths: the visible light continuous zoom system optical path and the long-wave infrared system optical path.

[0108] The visible light system is a secondary imaging system, which is composed of a primary imaging system consisting of a primary reflector 1, a secondary reflector spectral beam splitter 2, a first folding mirror 3, and a correction mirror group. The primary imaging system images the target on the primary image plane, and then images the target on the target surface of the detector through a visible light continuous zoom lens group, realizing a visible light system focal length of 1500mm to 3000mm continuous zoom, wherein the primary imaging system is composed of a primary reflector 1, a secondary reflector (spectral beam splitter 2), a first folding mirror 3, and a correction mirror group, the primary image focal length is 3220mm, the relative aperture is 1 / 8.05, and the field of view is 0.84°; the focal length of the visible light continuous zoom lens group is: 100mm to 200mm, the image side numerical aperture NA is: 0.14 to 0.064, and the image side paraxial image height is 11mm.

[0109] In addition, the aperture stop of the visible light continuous zoom optical system of the present invention is arranged after the compensation lens group and is conjugate with the main reflector 1; in the visible light continuous zoom optical system, the primary image system and the first lens of the visible light continuous zoom lens group constitute an afocal telephoto system with a magnification of 14.8 times. There is a parallel optical path behind the first lens 8 of the visible light continuous zoom lens group, and an attenuation plate can also be arranged here to realize the optical dimming function.

[0110] The long-wave infrared system is also a secondary imaging system, which is composed of a primary imaging system consisting of a main reflector 1, a spectral splitter element 2, a third folding mirror 20, and a fourth folding mirror 21. The primary imaging system images the target on a primary image plane, which is then deflected by the fifth folding mirror 22 and incident on the long-wave infrared projection mirror group, and finally imaged on the target surface of the long-wave infrared detector.

[0111] Figure 4 Shown is the compensation detection optical path diagram of the long-wave infrared projection mirror group.

[0112] Figure 5 Shown is the MTF curve of the optical system with a spatial frequency of 50lp / mm and a visible light continuous zoom telephoto of 3000mm. Figure 6Shown is the MTF curve of the optical system with a spatial frequency of 50lp / mm and a visible light continuous zoom short focus of 1500mm. Figure 7 Shown is the MTF curve of the optical system with a spatial frequency of 33lp / mm and a long-wave infrared focal length of 800mm. Figure 8 The figure shows the MTF curve of the optical system with a spatial frequency of 33lp / mm and a long-wave infrared compensation detection optical path. Figures 5 to 8 It can be seen that at the corresponding spatial frequency, the MTF of each subsystem is close to the diffraction limit and has high imaging quality, meeting the system's requirements for high-resolution and high-contrast imaging of the target.

[0113] Figures 9 to 11 The spherical aberration (left), field curvature (middle) and distortion curve (right) of the optical system of the visible light continuous zoom system with a telephoto focal length of 3000mm; the spherical aberration (left), field curvature (middle) and distortion curve (right) of the optical system of the visible light continuous zoom system with a short focal length of 1500mm; and the spherical aberration (left), field curvature (middle) and distortion curve (right) of the optical system of the long-wave infrared focal length of 800mm. Figures 9 to 11 It can be seen that the system has smaller distortion, which meets the system's requirements for high-precision measurement of the target.

Claims

1. A high-performance visible light-long-wave infrared two-in-one optical system, characterized by: It comprises a main reflector (1), a spectral splitting element (2), a visible light continuous zoom optical module, and a long-wave infrared optical module; The spectral beam splitting element (2) is located on the reflection light path of the main reflector (1); the light beam from the target object is reflected by the main reflector (1) and reaches the spectral beam splitting element (2) and is then split into two paths, one of which is reflected by the spectral beam splitting element (2) and enters the visible light continuous zoom optical module, and the other is transmitted by the spectral beam splitting element (2) and enters the long-wave infrared optical module; The main reflector (1), the spectrum splitting element (2) and the visible light continuous zoom optical module together constitute a visible light continuous zoom optical system, which is used to receive visible light in a light beam; The main reflector (1), the spectral splitting element (2) and the long-wave infrared optical module together form a long-wave infrared optical system for receiving long-wave infrared light in a light beam.

2. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 1 is characterized in that: The visible light continuous zoom optical module comprises a first folding mirror (3), a correction mirror group, a second folding mirror (4) and a visible light continuous zoom mirror group which are sequentially arranged along the reflection light path of the spectrum splitting element (2); wherein the first folding mirror (3) and the second folding mirror (4) are respectively used for turning the light path; The correction lens group comprises a first correction lens (5), a second correction lens (6) and a third correction lens (7) which are arranged in sequence along the optical path; wherein the first correction lens (5) is a meniscus heavy flint lens with a negative focal length convex toward the object side; the second correction lens (6) is a meniscus heavy phosphorus crown glass with a positive focal length convex toward the image side; and the third correction lens (7) is a meniscus light crown lens with a positive focal length convex toward the image side. The visible light continuous zoom lens group comprises a first lens (8), a second lens (9), a third lens (10), a fourth lens (11), a fifth lens (12), a first cemented lens (13), a second cemented lens (14), a tenth lens (15), a third cemented lens (16), a thirteenth lens (17), a fourteenth lens (18), and a fifteenth lens (19) which are sequentially arranged along an optical path; by adjusting the positions of the fifth lens (12), the first cemented lens (13), the second cemented lens (14), and the tenth lens (15) along the optical axis, the visible light continuous zoom is achieved, wherein the fifth lens (12) and the first cemented lens (13) form a variable magnification lens group which moves along the optical axis toward the image plane, and the second cemented lens (14) and the tenth lens (15) form a compensation lens group which moves along the optical axis toward the object plane; The first lens (8) is a plano-convex heavy flint lens with positive optical power; The second lens (9) is a negative power biconcave heavy flint lens; The third lens (10) is a positive power biconvex fluor crown lens; The fourth lens (11) is a positive power biconvex fluor crown lens; The fifth lens (12) is a meniscus heavy flint lens with positive refractive power and convex toward the object side; The first cemented lens (13) is a double concave cemented lens with negative optical power, which is formed by cementing a sixth lens (131) and a seventh lens (132), wherein the sixth lens (131) is arranged close to the fifth lens (12), and is a meniscus heavy flint lens with positive optical power convex toward the image side, and the seventh lens (132) is a heavy flint lens with negative optical power and double concave; The second cemented lens (14) is a biconvex cemented lens with positive focal power, which is formed by cementing an eighth lens (141) and a ninth lens (142), wherein the eighth lens (141) is arranged close to the seventh lens (132), and is a meniscus heavy lanthanum flint lens with negative focal power convex toward the object side, and the ninth lens (142) is a biconvex lanthanum crown lens with positive focal power; The tenth lens (15) is a biconvex crystalline lens with positive optical power; The third cemented lens (16) is a biconvex cemented lens with positive focal power, which is formed by cementing an eleventh lens (161) and a twelfth lens (162), wherein the eleventh lens (161) is arranged close to the tenth lens (15), and is a meniscus lanthanum flint lens with negative focal power and convex toward the object side, and the twelfth lens (162) is a heavy flint lens with positive focal power and biconvex; The thirteenth lens (17) is a negative power biconcave heavy flint lens; The fourteenth lens (18) is a meniscus heavy flint lens with positive refractive power and convex toward the image side; The fifteenth lens (19) is a meniscus heavy lanthanum flint lens with positive refractive power and convex toward the object side.

3. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 2 is characterized in that: The thickness of the first correction mirror (5) is 25.54 mm, the radius of curvature of the front surface is 101.33 mm, and the radius of curvature of the rear surface is 74.42 mm; The thickness of the second correction mirror (6) is 14.00 mm, the radius of curvature of the front surface is -400.56 mm, and the radius of curvature of the rear surface is -181.49 mm; The thickness of the third correction mirror (7) is 19.99 mm, the radius of curvature of the front surface is -56.91 mm, and the radius of curvature of the rear surface is -61.7 mm; The thickness of the first lens (8) is 15.00 mm, the front surface is a plane, and the radius of curvature of the rear surface is -163.00 mm; The thickness of the second lens (9) is 6.00 mm, the radius of curvature of the front surface is -154.10 mm, and the radius of curvature of the rear surface is 108.00 mm; The thickness of the third lens (10) is 18.38 mm, the radius of curvature of the front surface is 172.92 mm, and the radius of curvature of the rear surface is -192.49 mm; The thickness of the fourth lens (11) is 17.81 mm, the radius of curvature of the front surface is 110.70 mm, and the radius of curvature of the rear surface is -9546.83 mm; The fifth lens (12) has a thickness of 19.79 mm, a radius of curvature of the front surface of 88.77 mm, and a radius of curvature of the rear surface of 113.28 mm; The sixth lens (131) has a thickness of 19.56 mm, a curvature radius of the front surface of -356.66 mm, and a curvature radius of the rear surface of -74.28 mm; The seventh lens (132) has a thickness of 15.08 mm, a curvature radius of the front surface of -74.28 mm, and a curvature radius of the rear surface of 87.29 mm; The eighth lens (141) has a thickness of 6.20 mm, a curvature radius of the front surface of 19581.11 mm, and a curvature radius of the rear surface of 80.32 mm; The thickness of the ninth lens (142) is 11.11 mm, the radius of curvature of the front surface is 80.32 mm, and the radius of curvature of the rear surface is -121.49 mm; The thickness of the tenth lens (15) is 9.42 mm, the radius of curvature of the front surface is 88.98 mm, and the radius of curvature of the rear surface is -187.54 mm; The thickness of the eleventh lens (161) is 5.45 mm, the radius of curvature of the front surface is 296.82 mm, and the radius of curvature of the rear surface is 36.94 mm; The thickness of the twelfth lens (162) is 25.00 mm, the radius of curvature of the front surface is 36.94 mm, and the radius of curvature of the rear surface is -947.764 mm; The thirteenth lens (17) has a thickness of 25.00 mm, a curvature radius of the front surface of -83.082 mm, and a curvature radius of the rear surface of 535.35 mm; The thickness of the fourteenth lens (18) is 5.47 mm, the radius of curvature of the front surface is -78.858 mm, and the radius of curvature of the rear surface is -54.565 mm; The thickness of the fifteenth lens (19) is 25.00 mm, the radius of curvature of the front surface is 54.217 mm, and the radius of curvature of the rear surface is 46.998 mm.

4. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 1, characterized in that: The long-wave infrared optical module comprises a third folding mirror (20), a fourth folding mirror (21), a fifth folding mirror (22) and a long-wave infrared projection mirror group, which are sequentially arranged along the transmission light path of the spectral light splitting element (2); wherein the third folding mirror (20), the fourth folding mirror (21) and the fifth folding mirror (22) are respectively used for turning the light path; The long-wave infrared projection mirror group comprises a first long-wave mirror (23), a second long-wave mirror (24), a third long-wave mirror (25), and a fourth long-wave mirror (26) which are arranged in sequence along the optical path; The first long-wave mirror (23) is a meniscus germanium lens with positive focal power and convex toward the object side; The second long-wave mirror (24) is a meniscus germanium lens with negative optical power and convex toward the image side; The third long-wave mirror (25) is a meniscus ZnS lens with negative optical power and convex toward the image side; The fourth long-wave mirror (26) is a meniscus germanium lens with positive focal power and convex toward the object side.

5. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 4 is characterized in that: A compensating mirror (27) is provided at the light incident end of the first long-wave mirror (23) for detecting the long-wave infrared projection mirror group, wherein the compensating mirror (27) is a meniscus germanium lens with negative optical power and convex toward the object side.

6. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 5, characterized in that: The first long-wave mirror (23) has a thickness of 10.00 mm, a radius of curvature of the front surface of 106.1128 mm, and a radius of curvature of the rear surface of 355.04 mm; The second long-wave mirror (24) has a thickness of 8.00 mm, a front surface that is aspherical, a vertex curvature radius of -117.498 mm, and a rear surface that has a curvature radius of -147.996 mm; The thickness of the third long-wave mirror (25) is 20.00 mm, the radius of curvature of the front surface is -27.84 mm, and the radius of curvature of the rear surface is -42.642 mm; The fourth long-wave mirror (26) has a thickness of 5.00 mm, a curvature radius of the front surface of 64.325 mm, and a curvature radius of the rear surface of 120.0 mm; The thickness of the compensation mirror (27) is 9.16 mm, the curvature radius of the front surface is 498.85 mm, and the rear surface is an aspherical surface with a vertex curvature radius of 163.00 mm.

7. The high-performance visible light-long-wave infrared two-in-one optical system according to any one of claims 1 to 6, characterized in that: The main reflector (1) is a hyperbolic surface, the vertex curvature radius of which is -1809.3 mm, and the quadratic curve constant k1=-1.04; The spectral splitting element (2) is a meniscus-shaped hyperbolic germanium lens with positive focal power and convex toward the object side, with a thickness of 20.00 mm, a vertex curvature radius of the front surface of -815.451 mm, and a quadratic curve constant k2=-3.555; a vertex curvature radius of the rear surface of -526.94 mm, and a quadratic curve constant k3=-1.

9.

8. The high-performance visible light-long-wave infrared two-in-one optical system according to claim 7, characterized in that: The visible light continuous zoom optical system has an aperture of 400 mm, a focal length of 1500 mm to 3000 mm, a relative aperture of 1 / 3.75 to 1 / 7.5, and a field of view of 0.42° to 0.84°; The long-wave infrared optical system has an aperture of 400 mm, a focal length of 800 mm, a relative aperture of 1 / 2, and a field of view of 0.44°.

Images