CN118151352A - Long-focus infrared continuous zooming optical system of L-shaped light path - Google Patents
Long-focus infrared continuous zooming optical system of L-shaped light path Download PDFInfo
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- 239000005387 chalcogenide glass Substances 0.000 claims description 3
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- 229910052732 germanium Inorganic materials 0.000 claims description 3
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims description 3
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Abstract
The invention relates to a long-focus infrared continuous zooming optical system of an L-shaped optical path, which consists of a lens group and a plane-turning reflecting mirror, and adopts a three-component zooming structure form of a double compensation group, thereby effectively shortening the length of the optical system while realizing 30-180 mm large zoom ratio continuous zooming; the folding reflector is introduced to turn the optical path, so that the axial length of the system is shortened, and the miniaturization of the system is realized; through the combined configuration of the focal power of each lens in the system, the optical system has smooth and continuous motion curve and no inflection point in the zooming process, thereby ensuring clear imaging in the whole process of zooming and avoiding the clamping stagnation phenomenon.
Description
Technical Field
The invention relates to the field of infrared optical systems, in particular to a long-focus infrared continuous zooming optical system of an L-shaped optical path.
Background
Currently, with the development of infrared technology, the area array scale of uncooled infrared detectors is continuously increased, the resolution is continuously improved, and the technology of large area array and high resolution detectors with the resolution of 1024×768 and 12 μm is mature, so that the uncooled infrared detectors have been widely applied.
The photoelectric system for searching and identifying the target requires an infrared thermal imaging system to realize the target searching with a large field of view and the small field of view identification of a long-distance target. Therefore, the monoscopic infrared optical system cannot meet the requirement. The optical system of the thermal infrared imager needs to be designed as a zoom optical system to achieve this function. The continuous zooming infrared optical system has wide coverage of short focal length and large view field and high resolution of long focal length and small view field. A large field of view may be used to search for a target over a large area and a small field of view may be used to identify the target. The target image can be always kept clear in the zooming process, the transformation of any view field in the zooming range can be realized, the tracking target can not be lost in the continuous zooming process, and the proper working view field can be selected according to the scene and the target characteristics, so that the man-machine efficacy is greatly improved.
At present, most high-resolution infrared continuous optical systems are infrared detectors with the adaptive resolution of 640×512, continuous zoom optical systems with the adaptive resolution of 1024×768 are fewer, the zoom ratio is small, and long-distance target identification requirements are difficult to realize.
The Chinese patent application with the application number 201521011390.9 discloses a long-focus long-wave infrared continuous zoom lens, the effective focal length of the zoom lens is 35 mm-180 mm, the F number is 1.2, the total length of an optical system is 260mm, the maximum caliber is 175mm, the resolution of an adaptive detector is 640 multiplied by 480, and the pixel size is 25 mu m. The optical system is long, large in size and low in optical resolution, and cannot be adapted to the existing novel long-wave infrared detector with the resolution of 1024 multiplied by 768 and the pixel size of 12 mu m.
The Chinese patent application with the application number of 201721052438.X discloses a long-focus long-wave infrared continuous zoom lens, wherein the focal length of the system is 30-180 mm, the zoom ratio is 6 times, the adaptive resolution is 640 multiplied by 480, the pixel size is a 17-micrometer long-wave detector, the total length of an optical system is 305mm, and the maximum caliber is 152mm. The optical system is long and large in size, is difficult to meet the requirements of miniaturization and light weight in practical application, and cannot be adapted to the current novel long-wave infrared detector with the resolution of 800 multiplied by 600, the pixel size of 17 mu m or the resolution of 1024 multiplied by 768, and the pixel size of 12 mu m.
The Chinese patent application with the application number 201810040650.7 discloses a high-definition long-focus long-wave infrared lens, the focal length of the system is 25-300 mm, and the system can be matched with 1024X 768 and 1280X 1280 high-resolution large-area array long-wave infrared detectors. The total length of the optical system is 342.82mm, the length is longer, the volume is large, and the practical application is limited.
Chinese patent CN209182571U, CN209182572U, CN203965714U discloses several long-focus long-wave infrared zoom optical systems, but the focal length of the focal length end is either shorter and all adapt to a long-wave infrared detector with resolution of 640 x 480.
Disclosure of Invention
The invention aims to solve the technical problem that a long-wave infrared long-focus lens suitable for a current high-resolution detector is difficult to realize miniaturization and large zoom ratio, and provides a long-focus infrared continuous zooming optical system of an L-shaped optical path.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
The long-focus infrared continuous zooming optical system of the L-shaped optical path comprises a first meniscus positive lens, a first biconcave negative lens, a first biconvex positive lens, a second biconvex negative lens, a second biconvex positive lens, a plane turning mirror and a second meniscus positive lens which are coaxially arranged in sequence along an optical axis from an object side to an image side, wherein the plane turning mirror is positioned between the second biconvex positive lens and the second meniscus positive lens, an included angle between the normal line of the plane turning mirror and the optical axis of the system is 45 degrees, and the included angle between the emergent light of the second biconvex positive lens and the incident light of the second meniscus positive lens is 90 degrees through the plane turning mirror, wherein the first biconvex negative lens is a variable-magnification group, the first biconvex positive lens is a first compensation group, and the second biconvex negative lens is a second compensation group.
Further, when the system changes from short focus to long focus, the zoom group moves towards the direction close to the plane turning mirror; when the system changes from short focus to long focus, the first compensation group and the second compensation group move towards the direction far away from the plane turning reflector.
Further, the interval between the centers of the first meniscus positive lens and the first biconcave negative lens is 20-63.3 mm, the interval between the centers of the first biconcave negative lens and the first biconvex positive lens is 5.8-90.3 mm, the interval between the centers of the first biconvex positive lens and the second biconcave negative lens is 8.2-38.6 mm, and the interval between the centers of the second biconcave negative lens and the second biconvex positive lens is 4.2-14.9 mm.
Further, in the process of changing from short focus to long focus, the stroke of the first biconcave negative lens is 43.3mm, the stroke of the first biconvex positive lens is 41.2mm, and the stroke of the second biconcave negative lens is 10.7mm.
Further, the image plane defocus compensation of the system in the temperature range of-40 ℃ to +60 ℃ is realized by adopting the mode of axially moving the second meniscus positive lens, and the system defocus compensation caused by the distance change of the observed scenery is realized, so that the clear imaging of objects in different distances is ensured.
Further, the first meniscus positive lens, the first biconcave negative lens, the first biconvex positive lens and the second meniscus positive lens are all made of monocrystalline germanium Ge; the second biconcave negative lens is made of chalcogenide glass IRG206, and the second biconvex positive lens is made of zinc selenide ZNSE.
Further, the first meniscus positive lens satisfies the following conditions: f 1/f is more than or equal to 0.8 and less than or equal to 1.0, wherein f is the focal length of the optical system in a long focal state, and f 1 is the effective focal length of the first meniscus positive lens;
The first biconcave negative lens satisfies the following conditions: -0.3 +.f 2/f +.0.2, where f is the focal length of the optical system in the tele state and f 2 is the effective focal length of the first biconcave negative lens;
The first biconvex positive lens meets the following conditions: f 3/f is more than or equal to 0.3 and less than or equal to 0.4, wherein f is the focal length of the optical system in a long focal state, and f 3 is the effective focal length of the first biconvex positive lens;
the second biconcave negative lens satisfies the following conditions: -0.8 +.f 4/f +.0.6, where f is the focal length of the optical system in the tele state and f 4 is the effective focal length of the second biconcave negative lens;
The second biconvex positive lens satisfies the following conditions: f 5/f is more than or equal to 1.8 and less than or equal to 2.0, wherein f is the focal length of the optical system in a long focal state, and f 5 is the effective focal length of the second biconvex positive lens;
the second meniscus positive lens satisfies the following conditions: f 7/f is more than or equal to 0.2 and less than or equal to 0.4, wherein f is the focal length of the long focal state of the optical system, and f 7 is the effective focal length of the second meniscus lens.
The emergent surface of the first biconcave negative lens, the incident surface of the second biconcave negative lens and the incident surface of the second meniscus positive lens are all aspheric.
The incidence surface of the first biconvex positive lens is an aspheric surface, and a continuous relief structure is machined on the aspheric surface substrate by diamond turning to form a diffraction aspheric surface.
The technical parameters of the optical system are as follows: working wave band: 8-12 μm; f #: 1.2; focal length: 30 mm-180 mm; the field of view is: 23.2 degrees x 17.5 degrees to 3.91 degrees x 2.93 degrees; adapting 1024×768, 12 μm long wave infrared detector; wherein, F # is F/D, F is the focal length of the optical system, and D is the diameter of the entrance pupil.
The beneficial effects are that:
1. The optical system can be adapted to a long-wave detector with the current resolution of 1024 multiplied by 768 and 12 mu m, adopts a three-component zooming structure form of a double compensation group, and effectively shortens the length of the optical system while realizing continuous zooming with a large zoom ratio of 30mm to 180 mm; the folding reflector is introduced to turn the optical path, so that the length of the system on the axis is shortened, the volume of the optical path system is smaller than 222mm (length) x 170mm (width) x 170mm (height), and the miniaturization of the system is realized.
2. Through the combined configuration of the focal power of each lens in the system, the optical system has smooth and continuous motion curve and no inflection point in the zooming process, thereby ensuring clear imaging in the whole process of zooming and avoiding the clamping stagnation phenomenon.
Drawings
FIG. 1 is a light path diagram of an optical system of the present invention in a short focal length of 30 mm;
FIG. 2 is a light path diagram of the optical system of the present invention in a mid-focal 90mm state;
FIG. 3 is a view showing the optical path of the optical system of the present invention in a 180mm long focal length state;
FIG. 4 is a graph of the transfer function of an optical system of the present invention in the short focal length 30mm regime;
FIG. 5 is a graph of the transfer function of an optical system of the present invention at a mid-focus 90mm condition;
FIG. 6 is a graph of the transfer function of an optical system of the present invention in a 180mm long focal length state;
FIG. 7 is a spot diagram of an optical system of the present invention in a short focal length of 30 mm;
FIG. 8 is a spot diagram of an optical system of the present invention in a mid-focal 90mm position;
FIG. 9 is a spot diagram of an optical system of the present invention in a 180mm tele state;
FIG. 10 is a graph showing the motion of a variable magnification group and a compensation group in the zooming process of the optical system of the present invention.
In the figure: 1 is a first meniscus positive lens, 2 is a first biconcave negative lens, 3 is a first biconvex positive lens, 4 is a second biconcave negative lens, 5 is a second biconvex positive lens, 6 is a plane mirror, 7 is a second meniscus positive lens, and 8 is an image plane.
Detailed Description
In order that the above features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. It should be appreciated that where the terms "upper," "lower," "front," "back," "left," "right," etc., indicate or refer to an orientation or positional relationship, it is merely in correspondence with the drawings of the present application, and for convenience of description of the present application, it is not intended to indicate or imply that the device or element in question must have a particular orientation.
The terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying any relative importance in terms of the order in which lenses of this type appear.
In the drawings, the figures are merely examples and are not drawn to scale.
As a general knowledge, the direction close to the object space is the object space, the direction close to the image space is the image space, and the two surfaces of the lens are an incident surface and an emergent surface in sequence from the object space to the image space. The object side refers to the light incident side, and the image side refers to the emergent side. The surface of each lens facing the object side of the two surfaces is called the object side surface, and the surface of each lens facing the image side of the two surfaces is called the image side surface.
The long-focus infrared continuous zooming optical system of the L-shaped optical path as shown in fig. 1 to 3 consists of a first meniscus positive lens 1, a first biconcave negative lens 2, a first biconvex positive lens 3, a second biconcave negative lens 4, a second biconvex positive lens 5, a plane turning mirror 6 and a second meniscus positive lens 7 which are sequentially arranged from the object side to the image side.
The first meniscus positive lens 1, the first biconcave negative lens 2, the first biconvex positive lens 3, the second biconcave negative lens 4, the second biconvex positive lens 5, the second meniscus positive lens 7 are coaxially arranged from the object space to the image space along the optical axis direction, the plane turning mirror 6 is positioned between the second biconvex positive lens 5 and the second meniscus positive lens 7, the included angle between the normal line of the plane turning mirror 6 and the optical axis of the system is 45 degrees, and the included angle between the emergent ray of the second biconvex positive lens 5 and the incident ray of the second meniscus positive lens 7 is 90 degrees through the plane turning mirror 6.
The first meniscus positive lens 1 is arranged towards the plane turning mirror 6, and the second meniscus positive lens 7 is arranged away from the plane turning mirror 6.
The zoom group of the optical system consists of a first biconcave negative lens 2, the focal length of the system is changed by the axial movement of the first biconcave negative lens 2, and when the system changes from short focus to long focus, the zoom lens moves towards the direction close to the plane turning mirror 6; the first biconvex positive lens 3 is a first compensation group, the second biconcave negative lens 4 is a second compensation group, and when the system changes from short focus to long focus, the first compensation group and the second compensation group move towards the direction far away from the plane turning mirror 6.
Further, the center interval between the first meniscus positive lens 1 and the first biconcave negative lens 2 is 20-63.3 mm, the center interval between the first biconcave negative lens 2 and the first biconvex positive lens 3 is 5.8-90.3 mm, the center interval between the first biconvex positive lens 3 and the second biconcave negative lens 4 is 8.2-38.6 mm, and the center interval between the second biconcave negative lens 4 and the second biconvex positive lens 5 is 4.2-14.9 mm.
In the process of changing from short focus to long focus, the stroke of the first biconcave negative lens 2 (variable power group) is 43.3mm, the stroke of the first biconvex positive lens 3 (first compensation group) is 41.2mm, and the stroke of the second biconcave negative lens 4 (second compensation group) is 10.7mm.
The optical system adopts the mode of axially moving the second meniscus positive lens 7 to realize the out-of-focus compensation of the image plane of the system in the temperature range of-40 ℃ to +60 ℃ and the out-of-focus compensation of the system caused by the distance change of the observed scenery, thereby ensuring the clear imaging of objects in different distances.
Preferably, the materials of the first meniscus positive lens 1, the first biconcave negative lens 2, the first biconvex positive lens 3 and the second meniscus positive lens 7 are all single crystal germanium (Ge); the second biconcave negative lens 4 is made of chalcogenide glass IRG206, and the second biconvex positive lens 5 is made of zinc selenide (ZNSE); the plane turning reflector is made of quartz glass.
The specific light transmission path of the optical system is that light emitted by external scenery infrared radiation is converged by the first meniscus positive lens 1, then reaches the first biconcave negative lens 2, diverged by the first biconcave negative lens 2, then reaches the first biconvex positive lens 3, converged by the first biconvex positive lens 3, then reaches the second biconcave negative lens 4, diverged by the second biconcave negative lens 4, then reaches the second biconvex positive lens 5, converged by the second biconvex positive lens 5, then reaches the plane deflection mirror 6, then reaches the second meniscus positive lens 7 after being reflected by the plane deflection mirror 6, and finally forms an image on the image plane 8 after being converged by the second meniscus positive lens 7.
Preferably, the first meniscus positive lens 1 satisfies the following conditions: f 1/f is more than or equal to 0.8 and less than or equal to 1.0, wherein f is the focal length of the optical system in a long focal state, and f 1 is the effective focal length of the first meniscus positive lens 1;
The first biconcave negative lens 2 satisfies the following conditions: -0.3 +.f 2/f +.0.2, where f is the focal length of the optical system in the tele state and f 2 is the effective focal length of the first biconcave negative lens 2;
The first biconvex positive lens 3 satisfies the following conditions: f 3/f is more than or equal to 0.3 and less than or equal to 0.4, wherein f is the focal length of the optical system in a long focal state, and f 3 is the effective focal length of the first biconvex positive lens 3;
The second biconcave negative lens 4 satisfies the following conditions: -0.8 +.f 4/f +.0.6, where f is the focal length of the optical system in the tele state and f 4 is the effective focal length of the second biconcave negative lens 4;
The second biconvex positive lens 5 satisfies the following conditions: f 5/f is more than or equal to 1.8 and less than or equal to 2.0, wherein f is the focal length of the optical system in a long focal state, and f 5 is the effective focal length of the second biconvex positive lens 5;
The second meniscus positive lens 7 satisfies the following conditions: f 7/f is more than or equal to 0.2 and less than or equal to 0.4, wherein f is the focal length of the long focal state of the optical system, and f 7 is the effective focal length of the second meniscus lens 7.
Table 1 shows technical indexes achieved by the present invention, wherein, F # (F number of optical system) has a calculation formula of F/D, F is a focal length of the optical system, and D is an entrance pupil diameter.
Table 1 technical index of the optical system of the present invention
Table 2 lists detailed data of examples of optical systems according to the present invention at focal lengths of 30mm to 180mm, including the surface shape, radius of curvature, thickness, material of each lens. The curvature radius and the thickness of the lens are in mm, and the curvature radius of the spherical surface and the aspheric surface refer to the curvature radius at the intersection point of the lens surface and the optical axis. The "surface number" in table 2 is counted along the light propagation direction, for example, the light incident surface of the first positive meniscus lens 1 is number S1, the light emergent surface is number S2, the other mirror surface numbers are the same, the first positive meniscus lens 1, the first biconcave negative lens 2, the first biconvex positive lens 3, the second biconcave negative lens 4, the second biconvex positive lens 5, and the curved surface of the second positive meniscus lens 7 along the object direction to the image direction are respectively labeled S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, and S12; the "radius" in table 2 represents the radius of curvature of the face, and the positive and negative discriminant principle is: the intersection point of the surface and the main optical axis is used as a starting point, and the curved surface center of the surface is used as an end point. If the connecting line direction is the same as the light propagation direction, the connecting line direction is positive, otherwise, the connecting line direction is negative. If the surface is a plane, the curvature radius of the surface is infinity; the "thickness" in table 2 gives the distance between two adjacent faces on the optical axis, and the positive and negative judgment principle is: the current vertex is used as a starting point, and the next vertex is used as an ending point. If the connecting line direction is the same as the light propagation direction, the connecting line direction is positive, otherwise, the connecting line direction is negative. If the material between the two faces is infrared, the thickness is indicative of the lens thickness, and if there is no material between the two faces, the air gap between the two lenses.
Table 2 detailed data of optical system of the embodiment of the present invention
In the L-shaped optical path long-focus infrared continuous zooming optical system, the emergent surface S4 of the first biconcave negative lens 2, the incident surface S7 of the second biconcave negative lens 4 and the incident surface S11 of the second meniscus positive lens 7 are all aspheric surfaces.
Further, the above-mentioned surface equation of each aspheric surface is:
Where z is the distance sagittal height of the aspherical surface at a position of R in the optical axis direction, C is the curvature, c=1/R, R is the radius of curvature of the lens surface, R is the radial coordinate perpendicular to the optical axis direction, k is a conic constant, a is a fourth-order aspherical coefficient, B sixth-order aspherical coefficient, and C is an eighth-order aspherical coefficient.
Table 3 lists the aspherical coefficients of the exit surface S4 of the first biconcave negative lens 2, the entrance surface S7 of the second biconcave negative lens 4, and the entrance surface S11 of the second positive meniscus lens 7 according to the present invention, expressed by scientific counting, for example, -1.894706e-007 for-1.894706 x 10 -7.
TABLE 3 aspherical coefficients of the invention
Further, the incident surface S5 of the first biconvex positive lens 3 is an aspheric surface, and a continuous relief structure is formed on the aspheric substrate by diamond turning to form a diffraction surface, which satisfies the following equation:
Wherein z is the distance vector height of the aspheric surface at a position with a height R along the optical axis direction, C is the curvature, c=1/R, R is the curvature radius of the lens surface, R is the radial coordinate perpendicular to the optical axis direction, k is a conic constant, a is a fourth-order aspheric coefficient, B sixth-order aspheric coefficient, and C is an eighth-order aspheric coefficient; HOR is the diffraction order, C 1、C2、C3 is the diffraction plane coefficient, λ 0 is the design center wavelength; n is the refractive index of the lens and n 0 is the refractive index of air.
TABLE 4 diffraction aspherical coefficients of the invention
Through optical design software simulation, as shown in fig. 4, 5 and 6, in the short-focus, medium-focus and long-focus states, at the characteristic frequency 42lp/mm corresponding to the detector, the transfer functions of the central view field are all larger than 0.2, and the transfer functions of the edge view fields are all larger than 0.1; as shown in fig. 7, 8 and 9, the diameters of the scattered spots of the system are equal to the sizes of the detector pixels in the spot array in the short-focus, medium-focus and long-focus states, and as shown in fig. 10, the zoom graph of the continuous zoom optical system is shown in the horizontal axis, the focal length of the continuous zoom optical system is shown in the horizontal axis, and the moving distances of the zoom group and the compensation group are shown in the vertical axis. The zooming curve of the system is smooth and continuous, no abrupt change point exists, and the clamping stagnation phenomenon of the system in the zooming process can be effectively avoided.
The present invention is not limited to the above-mentioned embodiments, but is intended to be limited to the following embodiments, and any modifications, equivalent changes and variations in the above-mentioned embodiments can be made by those skilled in the art without departing from the scope of the present invention.
Claims (10)
1. The long-focus infrared continuous zooming optical system of the L-shaped light path is characterized by comprising a first meniscus positive lens (1), a first biconcave negative lens (2), a first biconvex positive lens (3), a second biconcave negative lens (4), a second biconvex positive lens (5), a plane turning mirror (6) and a second meniscus positive lens (7), wherein the plane turning mirror (6) is positioned between the second biconvex positive lens (5) and the second meniscus positive lens (7), an included angle between the normal line of the plane turning mirror (6) and the optical axis of the system is 45 degrees, and an included angle between the emergent light of the second biconvex positive lens (5) and the incident light of the second meniscus positive lens (7) is 90 degrees through the plane turning mirror (6), the first biconvex negative lens (2) is a variable-magnification group, the first positive lens (3) is a first biconvex negative compensation group, and the second biconvex negative lens (4) is a second compensation group.
2. A long-focus infrared continuous-zoom optical system of L-shaped optical path according to claim 1, characterized in that said magnification-varying group is moved in a direction approaching the plane-deflecting mirror (6) when the system is changed from short focus to long focus; when the system changes from short focus to long focus, the first compensation group and the second compensation group move towards a direction far away from the plane turning mirror (6).
3. The continuous-zoom optical system for long-focus infrared of L-shaped optical path according to claim 1, wherein the distance between the centers of the first meniscus positive lens (1) and the first biconcave negative lens (2) is 20-63.3 mm, the distance between the centers of the first biconcave negative lens (2) and the first biconvex positive lens (3) is 5.8-90.3 mm, the distance between the centers of the first biconvex positive lens (3) and the second biconcave negative lens (4) is 8.2-38.6 mm, and the distance between the centers of the second biconcave negative lens (4) and the second biconvex positive lens (5) is 4.2-14.9 mm.
4. A tele infrared continuous-zoom optical system of an L-shaped optical path according to claim 3, characterized in that the stroke of the first biconcave negative lens (2) is 43.3mm, the stroke of the first biconvex positive lens (3) is 41.2mm, and the stroke of the second biconcave negative lens (4) is 10.7mm during the transition from short to long.
5. The L-shaped optical path long-focus infrared continuous-zoom optical system according to claim 1, wherein the image plane defocus compensation of the system in the temperature range of-40 ℃ to +60 ℃ and the system defocus compensation caused by the distance change of the observed scenery are realized by adopting a mode of axially moving the second meniscus positive lens (7), thereby ensuring clear imaging of objects in different distances.
6. The continuous-zoom optical system of L-shaped optical path according to claim 1, wherein the first meniscus positive lens (1), the first biconcave negative lens (2), the first biconvex positive lens (3) and the second meniscus positive lens (7) are made of single crystal germanium Ge; the second biconcave negative lens (4) is made of chalcogenide glass IRG206, and the second biconvex positive lens (5) is made of zinc selenide ZNSE.
7. The L-shaped optical path tele infrared continuous-zoom optical system of claim 1, wherein each lens focal length satisfies the following condition:
0.8≤f1/f≤1.0,-0.3≤f2/f≤-0.2,0.3≤f3/f≤0.4,-0.8≤f4/f≤-0.6,1.8≤f5/f≤2.0,0.2≤f7/f≤0.4;
Wherein: f is the focal length of the optical system in a long focal state;
f 1 is the effective focal length of the first meniscus positive lens (1);
f 2 is the full effective focal length of the first biconcave negative lens (2);
f 3 is the effective focal length of the first biconvex positive lens (3);
f 4 is the effective focal length of the second biconcave negative lens (4);
f 5 is the effective focal length of the second biconvex positive lens (5);
f 7 is the effective focal length of the second meniscus positive lens (7).
8. The continuous-zoom infrared optical system of L-shaped optical path according to claim 1, wherein the exit surface of the first biconcave negative lens (2), the entrance surface of the second biconcave negative lens (4), and the entrance surface of the second meniscus positive lens (7) are aspherical.
9. The continuous-zoom optical system of L-shaped optical path of claim 1, wherein the incident surface of the first biconvex positive lens (3) is an aspherical surface, and the continuous relief structure is formed on the aspherical substrate by diamond turning to form a diffraction aspherical surface.
10. The continuous-zoom optical system for long-focus infrared of L-shaped optical path according to claim 1, wherein the technical parameters of the optical system are as follows: working wave band: 8-12 μm; f #: 1.2; focal length: 30 mm-180 mm; the field of view is: 23.2 DEG x17.5 DEG to 3.91 DEG x2.93 DEG; a 1024x768 12 μm long wave infrared detector is adapted; wherein, F # is F/D, F is the focal length of the optical system, and D is the diameter of the entrance pupil.
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| CN202410163253.4A CN118151352A (en) | 2024-02-05 | 2024-02-05 | Long-focus infrared continuous zooming optical system of L-shaped light path |
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| CN202410163253.4A CN118151352A (en) | 2024-02-05 | 2024-02-05 | Long-focus infrared continuous zooming optical system of L-shaped light path |
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