Medium-short wave infrared continuous zooming swing-scanning optical system

Abstract

The invention provides a medium-short wave infrared continuous zooming swing-scanning optical system, and relates to the technical field of photoelectricity. The system comprises an objective lens group, a zoom lens group, a compensating lens group, a collimating lens group, a swing scanning lens (15), a convergent lens group and an optical filter (22) which are sequentially arranged along a main optical axis in the incident direction. Continuous zooming of the optical system with the focal length ranging from 65 mm to 560 mm is achieved by moving the lens in the optical axis direction, the optical system comprises the continuous zooming telescopic system and the convergence imaging system, the swing scanning mirror is designed between the continuous zooming telescopic system and the convergence imaging system, and small-view-field stable compensation and reverse scanning imaging are achieved. The short-wave common-aperture design in the optical system effectively reduces the occupied space, and facilitates the reduction of cost and the miniaturization of the system.

Description

Technical Field

[0001] The invention relates to the field of optoelectronic technology, and in particular to a medium- and short-wave infrared continuous zoom swing scanning optical system. Background Art

[0002] The medium- and short-wave wide-band infrared imaging system can observe different types of targets in the same optical system and obtain more target information than a single band. It is a typical wide-band system with outstanding advantages in authenticity identification, anti-stealth, multi-target tracking, etc. It is the development trend of high-end infrared detection imaging.

[0003] Existing design technologies are usually designed as wide-band continuous zoom or medium-wave and short-wave swing-sweep optical systems, and there are fewer designs of medium- and short-wave wide-band swing-sweep optical systems. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a medium- and short-wave infrared continuous zoom swing-scan optical system. The system adopts a medium-wave infrared and short-wave infrared common optical path design, and the working bands are 2.2μm~2.8μm, 3.7μm~4.8μm and 2.2μm~4.8μm. Imaging in different bands is achieved by switching filters, and continuous zoom of the optical system is achieved by moving the lens along the optical axis. The optical system includes a continuous zoom telescope system and a convergent imaging system. A swing-scan mirror is designed between the continuous zoom telescope system and the convergent imaging system to achieve stable compensation for small field of view and back-scanning imaging.

[0005] The purpose of the present invention is to provide a medium- and short-wave infrared continuous zoom swing scanning optical system, comprising: an objective lens group, a magnification lens group, a compensation lens group, a collimating lens group, a swing scanning mirror, a converging lens group and a filter arranged in sequence along the main optical axis of the incident direction.

[0006] Preferably, the objective lens group comprises: a first lens, a second lens, and a third lens arranged in sequence along the main optical axis of the incident direction; The zoom lens group comprises: a fourth lens and a fifth lens arranged in sequence along the main optical axis of the incident direction; The compensation lens group comprises: a sixth lens, a seventh lens, and an eighth lens arranged in sequence along the main optical axis of the incident direction; The collimating lens group comprises: a ninth lens, a reflector, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens, which are sequentially arranged along the main optical axis in the incident direction; The reflector folds the main optical axis by 90 degrees, so that the main optical axis incident on the ninth lens is perpendicular to the main optical axis incident on the tenth lens.

[0007] Preferably, the first lens material is silicon, the second lens material is silicon, the third lens material is germanium, the fourth lens material is silicon, the fifth lens material is germanium, the sixth lens material is zinc selenide, the seventh lens material is germanium, and the eighth lens material is silicon; The ninth lens material is zinc selenide, the reflector, the tenth lens material is germanium, the eleventh lens material is calcium fluoride, the twelfth lens material is zinc selenide, and the thirteenth lens material is zinc sulfide.

[0008] Preferably, the swing mirror deflects the light beam from the collimating lens group by 90 degrees; The material of the swing scanning mirror is fused quartz.

[0009] Preferably, the converging lens group includes: a fourteenth lens, a fifteenth lens, a sixteenth lens, a seventeenth lens, an eighteenth lens, and a nineteenth lens, which are sequentially arranged along the principal optical axis in the incident direction.

[0010] Preferably, the material of the fourteenth lens is silicon, the material of the fifteenth lens is germanium, the material of the sixteenth lens is silicon, the material of the seventeenth lens is silicon, the material of the eighteenth lens is germanium, and the material of the nineteenth lens is silicon.

[0011] Preferably, the optical filters include short-wave infrared, medium-wave infrared, and medium-short-wave wide-band infrared, and imaging of different bands of the wide-band detector is achieved by switching the optical filters; The filter material is silicon.

[0012] Preferably, the objective lens group converges the light beam, the zoom lens group and the compensation lens group move along the optical axis to change the focal length of the optical system, the collimator lens group makes the light beam emit parallel light, and the convergent lens group converges the parallel light to form an image on the detector image plane.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a medium- and short-wave infrared continuous zoom swing-scanning optical system. The system adopts a medium-wave infrared and short-wave infrared common optical path design, and the working bands are 2.2μm-2.8μm, 3.7μm-4.8μm and 2.2μm-4.8μm. Imaging in different bands is achieved by switching filters, and continuous zooming of the optical system is achieved by moving lenses along the optical axis. The optical system includes a continuous zoom telescope system and a convergent imaging system. A swing-scanning mirror is designed between the continuous zoom telescope system and the convergent imaging system to achieve stable compensation for small fields of view and back-scanning imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of small field of view imaging of the present invention.

[0015] Figure 2 It is a schematic diagram of medium field imaging of the present invention.

[0016] Figure 3 It is a schematic diagram of large field of view imaging of the present invention.

[0017] Figure 4 for Figure 1 MTF curves of specific embodiments.

[0018] Figure 5 for Figure 2 MTF curves of specific embodiments.

[0019] Figure 6 for Figure 3 MTF curves of specific embodiments. DETAILED DESCRIPTION

[0020] Several specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0021] The purpose of the present invention is to provide a medium- and short-wave infrared continuous zoom swing scanning optical system adopts a medium-wave infrared and short-wave infrared common optical path design, the working bands are 2.2μm-2.8μm, 3.7μm-4.8μm and 2.2μm-4.8μm, and different bands of imaging are achieved by switching filters. The optical design is realized by using five materials, silicon, germanium, zinc sulfide, zinc selenide, and calcium fluoride. The optical system focal length 65mm-560mm is continuously zoomed by moving the lens along the optical axis. The optical system includes a continuous zoom telescope system and a convergent imaging system. A swing scanning mirror is designed between the continuous zoom telescope system and the convergent imaging system to achieve small field of view stable compensation and reverse scanning imaging. The short-wave common aperture design in the optical system effectively reduces the occupied space, which is conducive to reducing costs and miniaturization of the system.

[0022] To achieve the above purpose, see Figure 1 As shown, a medium- and short-wave infrared continuous zoom swing scanning optical system provided by the present invention includes: an objective lens group, a magnification lens group, a compensation lens group, a collimating lens group, a swing scanning mirror 15, a converging lens group and a filter 22 arranged in sequence along the main optical axis in the incident direction.

[0023] The objective lens group includes: a first lens 1, a second lens 2, and a third lens 3 which are sequentially arranged along the main optical axis of the incident direction; The zoom lens assembly comprises: a fourth lens 4 and a fifth lens 5 which are arranged in sequence along the main optical axis in the incident direction; The compensation lens group comprises: a sixth lens 6, a seventh lens 7, and an eighth lens 8 which are arranged in sequence along the main optical axis in the incident direction; The collimating lens group comprises: a ninth lens 9, a reflector 10, a tenth lens 11, an eleventh lens 12, a twelfth lens 13, and a thirteenth lens 14, which are sequentially arranged along the main optical axis of the incident direction; The reflector 10 folds the main optical axis by 90 degrees, so that the main optical axis incident on the ninth lens 9 is perpendicular to the main optical axis incident on the tenth lens 11; The first lens 1 is made of silicon, the second lens 2 is made of silicon, the third lens 3 is made of germanium, the fourth lens 4 is made of silicon, the fifth lens 5 is made of germanium, the sixth lens 6 is made of zinc selenide, the seventh lens 7 is made of germanium, and the eighth lens 8 is made of silicon; The ninth lens 9 is made of zinc selenide, the reflector 10 and the tenth lens 11 are made of germanium, the eleventh lens 12 is made of calcium fluoride, the twelfth lens 13 is made of zinc selenide, and the thirteenth lens 14 is made of zinc sulfide.

[0024] The swing mirror 15 deflects the light beam from the collimating lens group by 90 degrees; The material of the swing mirror 15 is fused quartz.

[0025] The converging lens group comprises: a fourteenth lens 16, a fifteenth lens 17, a sixteenth lens 18, a seventeenth lens 19, an eighteenth lens 20, and a nineteenth lens 21 which are sequentially arranged along the main optical axis in the incident direction.

[0026] The material of the fourteenth lens 16 is silicon, the material of the fifteenth lens 17 is germanium, the material of the sixteenth lens 18 is silicon, the material of the seventeenth lens 19 is silicon, the material of the eighteenth lens 20 is germanium, and the material of the nineteenth lens 21 is silicon.

[0027] The optical filters 22 include short-wave infrared, medium-wave infrared, and medium-short-wave wide-band infrared. The wide-band detector can be imaged in different bands by switching the optical filters. The filter 22 is made of silicon.

[0028] The objective lens group converges the light beam, the variable magnification lens group and the compensation lens group move along the optical axis direction to change the focal length of the optical system, the collimating lens group makes the light beam emit parallel light, and the converging lens group converges the parallel light to form an image on the detector image plane.

[0029] In order to further illustrate the medium- and short-wave infrared continuous zoom swing scanning optical system provided by the present invention, the structural drawings are provided to illustrate it.

[0030] See also Figure 1As shown, a medium- and short-wave infrared continuous zoom swing scanning optical system comprises: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a reflector 10, a tenth lens 11, an eleventh lens 12, a twelfth lens 13, a thirteenth lens 14, a swing scanning mirror 15, a fourteenth lens 16, a fifteenth lens 17, a sixteenth lens 18, a seventeenth lens 19, an eighteenth lens 20, a nineteenth lens 21, and a filter 22, which are sequentially arranged along the main optical axis in the incident direction.

[0031] The first lens 1, the second lens 2, and the third lens 3 constitute an objective lens group; The fourth lens 4 and the fifth lens 5 form a zoom lens group; The sixth lens 6, the seventh lens 7 and the eighth lens 8 constitute a compensation lens group; The ninth lens 9, the tenth lens 11, the eleventh lens 12, the twelfth lens 13 and the thirteenth lens 14 constitute a collimating lens group; The fourteenth lens 16, the fifteenth lens 17, the sixteenth lens 18, the seventeenth lens 19, the eighteenth lens 20, and the nineteenth lens 21 constitute a converging lens group; The objective lens group realizes light beam convergence, the zoom lens group and the compensation lens group move along the optical axis to realize the change of the focal length of the optical system, the collimator lens group realizes the parallel light emission of the light beam, and the convergence lens group realizes the convergence of parallel light to form an image on the detector image plane.

[0032] The reflector 10 realizes a 90-degree deflection of the light beam; The swing scanning mirror 15 realizes 90-degree deflection of the light beam and stable compensation of small field of view and reverse scanning imaging; The filters 22 include three types: short-wave infrared, medium-wave infrared, and medium-short-wave wide-band infrared. Different bands of the wide-band detector can be imaged by switching the filters.

[0033] The present invention provides a medium- and short-wave infrared continuous zoom swing scanning optical system, wherein a first lens 1 is made of silicon, a second lens 2 is made of silicon, a third lens 3 is made of germanium, a fourth lens 4 is made of silicon, a fifth lens 5 is made of germanium, a sixth lens 6 is made of zinc selenide, a seventh lens 7 is made of germanium, an eighth lens 8 is made of silicon, a ninth lens 9 is made of zinc selenide, a reflector 10, a tenth lens 11 is made of germanium, an eleventh lens 12 is made of calcium fluoride, a twelfth lens 13 is made of zinc selenide, a thirteenth lens 14 is made of zinc sulfide, a fourteenth lens 16 is made of silicon, a fifteenth lens 17 is made of germanium, a sixteenth lens 18 is made of silicon, a seventeenth lens 19 is made of silicon, an eighteenth lens 20 is made of germanium, a nineteenth lens 21 is made of silicon, a swing scanning mirror 15 is made of fused quartz, and a filter 22 is made of silicon.

[0034] The main design indicators of a medium- and short-wave infrared continuous zoom swing scanning optical system provided by the present invention are shown in the following table: Table 1 Design specifications of medium and short wave infrared continuous zoom scanning optical system

[0035] In order to achieve the change of focal length of the optical system, the zoom lens group and the compensation lens group are moved along the optical axis. Figures 1 to 3 As shown, Figure 1 The figure is a schematic diagram of the imaging optical path of a small field of view (560mm focal length) of a specific embodiment of a medium- and short-wave infrared continuous zoom swing scanning optical system. Figure 2 The figure is a schematic diagram of the imaging optical path of the field of view (300mm focal length) in a specific embodiment of a medium- and short-wave infrared continuous zoom scanning optical system. Figure 3 The figure is a schematic diagram of the imaging optical path of a medium- and short-wave infrared continuous zoom swing scanning optical system in a specific embodiment with a large field of view (65mm focal length).

[0036] In this embodiment, the zoom position parameters of the small field of view, the medium field of view, and the large field of view are shown in Table 2.

[0037] Table 2 shows the zoom position parameters for small, medium and large fields of view

[0038] In this embodiment, the structural design parameters of each lens group are shown in Table 3, taking a small field of view as an example.

[0039] Table 3 shows the design parameters of each lens group structure

[0040] Figure 4 It is the MTF curve of the optical system with small field of view.

[0041] Figure 5 It is the field MTF curve in the optical system.

[0042] Figure 6 It is the MTF curve of the optical system with large field of view.

[0043] from Figures 4 to 6 It can be seen that the MTF curve of a medium- and short-wave infrared continuous zoom swing scanning optical system provided by the present invention is close to the diffraction limit in the 2.2μm to 4.8μm band, and the imaging quality of the optical system is good, meeting the use requirements of medium- and short-wave infrared wide-band optical systems.

[0044] It should be noted that the steps and methods used in the claims of the present invention are the same as those in the above-mentioned embodiments. In order to avoid redundancy, the present invention describes the preferred embodiments, but those skilled in the art may make other changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0045] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A medium- and short-wave infrared continuous zoom swing scanning optical system, characterized in that: include: An objective lens group, a magnification lens group, a compensation lens group, a collimating lens group, a sweeping mirror (15), a converging lens group and a filter (22) are sequentially arranged along a main optical axis in an incident direction.

2. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 1, characterized in that: The objective lens group comprises: a first lens (1), a second lens (2), and a third lens (3) which are arranged in sequence along the main optical axis in the incident direction; The variable magnification lens assembly comprises: a fourth lens (4) and a fifth lens (5) arranged in sequence along the main optical axis in the incident direction; The compensation lens group comprises: a sixth lens (6), a seventh lens (7), and an eighth lens (8) which are arranged in sequence along the main optical axis in the incident direction; The collimating lens group comprises: a ninth lens (9), a reflector (10), a tenth lens (11), an eleventh lens (12), a twelfth lens (13), and a thirteenth lens (14) arranged in sequence along the main optical axis in the incident direction; The reflector (10) folds the main optical axis by 90 degrees, so that the main optical axis incident on the ninth lens (9) is perpendicular to the main optical axis incident on the tenth lens (11).

3. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 2, characterized in that: The first lens (1) is made of silicon, the second lens (2) is made of silicon, the third lens (3) is made of germanium, the fourth lens (4) is made of silicon, the fifth lens (5) is made of germanium, the sixth lens (6) is made of zinc selenide, the seventh lens (7) is made of germanium, and the eighth lens (8) is made of silicon; The ninth lens (9) is made of zinc selenide, the reflector (10) and the tenth lens (11) are made of germanium, the eleventh lens (12) is made of calcium fluoride, the twelfth lens (13) is made of zinc selenide, and the thirteenth lens (14) is made of zinc sulfide.

4. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 1, characterized in that: The swinging scanning mirror (15) deflects the light beam from the collimating lens group by 90 degrees; The material of the sweep mirror (15) is fused quartz.

5. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 1, characterized in that: The converging lens group comprises: a fourteenth lens (16), a fifteenth lens (17), a sixteenth lens (18), a seventeenth lens (19), an eighteenth lens (20), and a nineteenth lens (21) which are arranged in sequence along a principal optical axis in the incident direction.

6. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 5, characterized in that: The material of the fourteenth lens (16) is silicon, the material of the fifteenth lens (17) is germanium, the material of the sixteenth lens (18) is silicon, the material of the seventeenth lens (19) is silicon, the material of the eighteenth lens (20) is germanium, and the material of the nineteenth lens (21) is silicon.

7. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 1, characterized in that: The optical filters (22) include three types: short-wave infrared, medium-wave infrared, and medium-short-wave wide-band infrared, and imaging of different bands of the wide-band detector is achieved by switching the optical filters; The filter (22) is made of silicon.

8. The medium- and short-wave infrared continuous zoom swing scanning optical system according to claim 1, characterized in that: The objective lens group converges the light beam, the variable magnification lens group and the compensation lens group move along the optical axis direction to change the focal length of the optical system, the collimating lens group makes the light beam emit parallel light, and the converging lens group converges the parallel light to form an image on the detector image plane.

Images