Medium-wave infrared collimation system with ultra-long exit pupil distance

Abstract

The utility model provides a medium-wave infrared collimation system with an ultra-long exit pupil distance, which comprises a front group of lenses used for imaging light beams emitted by a medium-wave infrared light source and a rear group of lenses used for collimating the light beams emitted by the medium-wave infrared light source, the front-group lens sequentially comprises a front-group lens I, a front-group lens II, a front-group lens III, a front-group lens IV, a front-group lens V, a front-group lens VI and a front-group lens VII from the front side to the rear side along the direction of an optical path; the rear-group lens comprises a rear-group lens I, a rear-group lens II, a rear-group lens III and a rear-group lens IV which are positioned behind the front-group lens VII in sequence from the front side to the rear side along the direction of the light path; the medium-wave infrared collimation system has the beneficial effects that the medium-wave infrared collimation system has an ultra-long exit pupil distance and a longer working distance, and also has a larger field angle, and the edge field of view has higher illumination uniformity, so that the special requirements of an infrared target simulator can be better met.

Description

Technical Field

[0001] The utility model relates to the technical field of infrared collimation systems, in particular to an ultra-long exit pupil distance mid-wave infrared collimation system. Background Art

[0002] The infrared target simulator is suitable for simulating infrared targets with various types of characteristics and is used for optical path test experiments; the infrared target simulator plays an important role in the fields of infrared target detection and recognition, semi-physical simulation, etc. The infrared target simulator, together with devices such as a scene generator, an infrared thermal imager, and a five-axis turntable, jointly constitutes a semi-physical simulation system, which can complete the simulation of infrared targets and the evaluation of the performance of detection devices; the digital image data generated by a computer is converted into an infrared image by a scene simulator and displayed on the scene generator. The infrared scene is projected onto the detector of the infrared thermal imager through an ultra-long exit pupil distance mid-wave infrared collimation system to reproduce the infrared scene.

[0003] The ultra-long exit pupil distance mid-wave infrared collimation optical system of the infrared target simulator mainly has three functions: one is to transmit the modulated reflected light beam on the scene generator to infinity to ensure clear imaging of the receiving system; the second is to meet the pupil matching between the infrared target simulator and the receiving system, so that there is no halo phenomenon in the receiving system and the imaging consistency is satisfied; the third is to achieve the matching between the positions of the scene element and the detector element to meet the consistency of the radiation of the scene and the reception of the system to be measured. However, the existing ultra-long exit pupil distance mid-wave infrared collimation optical system cannot simultaneously meet the requirements of having an ultra-long exit pupil distance, a long working distance, and a large field of view angle, thus unable to meet the special requirements of the infrared target simulator. Summary of the Utility Model

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide an ultra-long exit pupil distance mid-wave infrared collimation system, which is used to solve the problem that the existing ultra-long exit pupil distance mid-wave infrared collimation optical system cannot simultaneously meet the requirements of having an ultra-long exit pupil distance, a long working distance, and a large field of view angle.

[0005] To achieve the above purpose and other related purposes, the present utility model provides the following technical solutions:

[0006] An ultra-long exit pupil distance mid-wave infrared collimation system includes a front group of lenses for imaging the light beam emitted by a mid-wave infrared light source and a rear group of lenses for collimating the light beam emitted by the mid-wave infrared light source. Among them, the front group of lenses successively includes a first front group lens, a second front group lens, a third front group lens, a fourth front group lens, a fifth front group lens, a sixth front group lens, and a seventh front group lens from the front side to the rear side along the optical path direction, and the rear group of lenses successively includes a first rear group lens, a second rear group lens, a third rear group lens, and a fourth rear group lens located behind the seventh front group lens from the front side to the rear side along the optical path direction.

[0007] In an embodiment of the present utility model, the first front group lens is a plano-convex positive spherical lens, the second front group lens is a meniscus positive spherical lens, the third front group lens is a double-concave spherical lens, the fourth front group lens is a meniscus negative spherical lens, the fifth front group lens is a meniscus positive aspherical lens, the sixth front group lens is a meniscus positive spherical lens, and the seventh front group lens is a meniscus negative aspherical lens and a double-concave negative aspherical lens.

[0008] In an embodiment of the present utility model, the first rear group lens is a meniscus negative spherical lens, the second rear group lens is a meniscus positive aspherical lens, the third rear group lens is a meniscus negative spherical lens, and the fourth rear group lens is a meniscus positive spherical lens.

[0009] In an embodiment of the present utility model, an exit pupil position is provided behind the fourth rear group lens. The exit pupil distance of the mid-wave infrared collimation system is greater than 1200 mm, and the exit pupil diameter of the mid-wave infrared collimation system is greater than 40 mm. In this technical solution, the exit pupil distance of the mid-wave infrared collimation system is greater than 1200 mm. Therefore, the mid-wave infrared collimation system has an extremely long exit pupil distance, can meet the requirements of pupil matching for most receiving systems, and ensure the imaging quality.

[0010] In an embodiment of the present utility model, the distance from the light source of the mid-wave infrared collimation system to the first front group lens is greater than 200 mm. The focal length of the mid-wave infrared collimation system is 100 mm, and the F number is 2.4. Herein, the F number is the ratio of the focal length to the entrance pupil diameter. In this technical solution, the distance from the light source of the mid-wave infrared collimation system to the first front group lens is greater than 200 mm. Therefore, the mid-wave infrared collimation system has a long working distance, and thus a steering prism can be added between the scene generator and the mid-wave collimation system with an extremely long exit pupil distance.

[0011] In an embodiment of the present utility model, the field of view angle of the mid-wave infrared collimation system is greater than 10°. The MTF of the central field of view of the mid-wave infrared collimation system is > 0.4 at 30 lp / mm, the MTF of the edge field of view of the mid-wave infrared collimation system is > 0.35 at 30 lp / mm, and the distortion is < 2.5%. In this technical solution, the field of view angle of the mid-wave infrared collimation system is greater than 10°. Therefore, the mid-wave infrared collimation system has a large field of view angle, and the edge field of view has high illuminance uniformity.

[0012] As described above, a mid-wave infrared collimation system with an extremely long exit pupil distance of the present utility model has the following beneficial effects:

[0013] The mid-wave infrared collimation system in the present utility model has an extremely long exit pupil distance, which can meet the requirements of pupil matching for most receiving systems, ensuring imaging quality. Moreover, the mid-wave infrared collimation system also has a long working distance, so that a steering prism can be added between the scene generator and the mid-wave collimation system with an extremely long exit pupil distance. In addition, the mid-wave infrared collimation system also has a large field of view angle, and the edge field of view has high illuminance uniformity. Therefore, the present utility model can simultaneously meet the requirements of having an extremely long exit pupil distance, a long working distance, and a large field of view angle, and can better meet the special requirements of the infrared target simulator. Brief Description of the Drawings

[0014] Figure 1 It is an optical schematic diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0015] Figure 2 It is an optical schematic diagram of the front group of lenses in the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0016] Figure 3 It is an optical schematic diagram of the rear group of lenses in the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0017] Figure 4 It is a two-dimensional optical path diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0018] Figure 5 It is an optical MTF curve diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0019] Figure 6 It is an optical spot diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0020] Figure 7 It is an optical distortion diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model;

[0021] Figure 8 It is an optical relative illuminance diagram of the mid-wave infrared collimation system with an extremely long exit pupil distance disclosed in the embodiment of the present utility model.

[0022] Description of Component Labels

[0023] 1. First front group of lenses; 2. Second front group of lenses; 3. Third front group of lenses; 4. Fourth front group of lenses; 5. Fifth front group of lenses; 6. Sixth front group of lenses; 7. Seventh front group of lenses; 8. First rear group of lenses; 9. Second rear group of lenses; 10. Third rear group of lenses; 11. Fourth rear group of lenses; 12. Exit pupil position. Detailed Embodiment

[0024] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0025] Please refer to Figures 1 to 8 , the present utility model provides an ultra-long exit pupil distance mid-wave infrared collimation system, which is used in an infrared target simulator and belongs to the field of infrared hardware-in-the-loop simulation. It includes a front group of lenses for imaging the light beam emitted by a mid-wave infrared light source and a rear group of lenses for collimating the light beam emitted by the mid-wave infrared light source. Among them, the front group of lenses sequentially includes a first front group lens 1, a second front group lens 2, a third front group lens 3, a fourth front group lens 4, a fifth front group lens 5, a sixth front group lens 6, and a seventh front group lens 7 from the front side to the rear side along the optical path direction. The rear group of lenses sequentially includes a first rear group lens 8, a second rear group lens 9, a third rear group lens 10, and a fourth rear group lens 11 located behind the seventh front group lens 7 from the front side to the rear side along the optical path direction;

[0026] Among them, the first front group lens 1 is a plano-convex positive spherical lens, the second front group lens 2 is a meniscus positive spherical lens, the third front group lens 3 is a biconcave spherical lens, the fourth front group lens 4 is a meniscus negative spherical lens, the fifth front group lens 5 is a meniscus positive aspherical lens, the sixth front group lens 6 is a meniscus positive spherical lens, the seventh front group lens 7 is a meniscus negative aspherical lens biconcave negative aspherical lens, the first rear group lens 8 is a meniscus negative spherical lens, the second rear group lens 9 is a meniscus positive aspherical lens, the third rear group lens 10 is a meniscus negative spherical lens, and the fourth rear group lens 11 is a meniscus positive spherical lens. The mid-wave infrared collimation system adopts all conventional optical elements, which are suitable for processing, detection, and alignment.

[0027] An exit pupil position 12 is provided behind the fourth rear group lens 11. Among them, the exit pupil position 12 is an important concept in the optical system. It refers to the position of the image formed by the aperture stop of the optical system in the image space. This position can be represented by the exit pupil distance, and its diameter is represented by the exit pupil diameter. The position and diameter of the exit pupil jointly determine the position and aperture of the outgoing light beam. The concept of the exit pupil is opposite to that of the entrance pupil. The entrance pupil is the position where light enters the optical system, while the exit pupil is the position where light exits the system. For example, in a single-tube telescope, the exit pupil is the place where light enters the observer's eye after passing through the telescope; the exit pupil distance of the mid-wave infrared collimation system is greater than 1200 mm, and the exit pupil aperture of the mid-wave infrared collimation system is greater than 40 mm;

[0028] The distance from the light source of the mid-wave infrared collimation system to the first front group lens is greater than 200 mm. The focal length of the mid-wave infrared collimation system is 100 mm, and the F number is 2.4. Here, the F number is the ratio of the focal length to the entrance pupil diameter. The field of view angle of the mid-wave infrared collimation system is greater than 10°. The MTF of the central field of view of the mid-wave infrared collimation system at 30 lp / mm > 0.4, and the MTF of the marginal field of view of the mid-wave infrared collimation system at 30 lp / mm > 0.35, and the distortion < 2.5%. Here, MTF represents the imaging quality.

[0029] As can be seen from the above, the mid-wave infrared collimation system has a long working distance. The light beam emitted by the mid-wave infrared light source is imaged by the first front group lens in the mid-wave infrared collimation system and then collimated by the rear group lens, ensuring that the mid-wave infrared collimation system has a long exit pupil distance, thus meeting the special requirements of the infrared target simulator. Moreover, the mid-wave infrared collimation system has a large exit pupil diameter, that is, a large relative aperture, a field of view angle greater than 10°, and a very high illuminance uniformity in the marginal field of view, thus ensuring a high-quality parallel light beam output while meeting the special requirements of the infrared target simulator.

[0030] Furthermore, the mid-wave infrared collimation optical system with an ultra-long exit pupil distance is an important part of the infrared target simulator. It transmits the modulated reflected light beam on the scene generator to infinity, ensuring clear imaging of the receiving system. At the same time, it must meet the pupil matching between the infrared target simulator and the receiving system, so that there is no halo phenomenon in the receiving system and the imaging consistency is satisfied. Also, the exit pupil distance of the mid-wave infrared collimation system in the present utility model is greater than 1200 mm, so the mid-wave infrared collimation system has an ultra-long exit pupil distance; the distance from the light source of the mid-wave infrared collimation system to the first front group lens is greater than 200 mm, so the mid-wave infrared collimation system has a long working distance; the field of view angle of the mid-wave infrared collimation system is greater than 10°, so the mid-wave infrared collimation system has a large field of view angle and can better meet the special requirements of the infrared target simulator.

[0031] In summary, the mid-wave infrared collimation system in the present utility model has an ultra-long exit pupil distance, can meet the requirements of pupil matching for most receiving systems, ensure the imaging quality, and the mid-wave infrared collimation system also has a long working distance. Thus, a steering prism can be added between the scene generator and the mid-wave infrared collimation system with an ultra-long exit pupil distance. Moreover, the mid-wave infrared collimation system has a large field of view angle and a high illuminance uniformity in the marginal field of view. Therefore, the present utility model can simultaneously meet the requirements of having an ultra-long exit pupil distance, a long working distance, and a large field of view angle, and can better meet the special requirements of the infrared target simulator.

[0032] The above embodiments are only illustrative of the principles and effects of the present utility model, rather than limiting the present utility model. All equivalent modifications or changes made by those of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A medium-wave infrared collimation system with an ultra-long exit pupil distance, characterized in that: The invention comprises a front lens group for imaging a light beam emitted by a medium-wave infrared light source and a rear lens group for collimating the light beam emitted by the medium-wave infrared light source, wherein the front lens group comprises, from the front side to the rear side, a front lens group one (1), a front lens group two (2), a front lens group three (3), a front lens group four (4), a front lens group five (5), a front lens group six (6) and a front lens group seven (7) in sequence along the direction of the light path, and the rear lens group comprises, from the front side to the rear side, a rear lens group one (8), a rear lens group two (9), a rear lens group three (10) and a rear lens group four (11) located behind the front lens group seven (7) in sequence along the direction of the light path.

2. The ultra-long exit pupil distance medium-wave infrared collimation system according to claim 1, characterized in that: The front lens group one (1) is a plano-convex positive spherical lens, the front lens group two (2) is a meniscus positive spherical lens, the front lens group three (3) is a biconcave spherical lens, the front lens group four (4) is a meniscus negative spherical lens, the front lens group five (5) is a meniscus positive aspherical lens, the front lens group six (6) is a meniscus positive spherical lens, and the front lens group seven (7) is a meniscus negative aspherical lens or a biconcave negative aspherical lens.

3. The ultra-long exit pupil distance medium-wave infrared collimation system according to claim 1, characterized in that: The rear lens group one (8) is a meniscus negative spherical lens, the rear lens group two (9) is a meniscus positive aspherical lens, the rear lens group three (10) is a meniscus negative spherical lens, and the rear lens group four (11) is a meniscus positive spherical lens.

4. The ultra-long exit pupil distance medium-wave infrared collimation system according to claim 1, characterized in that: An exit pupil position (12) is arranged behind the rear lens group four (11), the exit pupil distance of the medium-wave infrared collimation system is greater than 1200 mm, and the exit pupil diameter of the medium-wave infrared collimation system is greater than 40 mm.

5. The ultra-long exit pupil distance medium-wave infrared collimation system according to claim 1, characterized in that: The distance from the light source of the medium-wave infrared collimation system to the front lens group one (1) is greater than 200 mm, the focal length of the medium-wave infrared collimation system is 100 mm, and the F number is 2.4, wherein the F number is the ratio of the focal length to the entrance pupil diameter.

6. The ultra-long exit pupil distance medium-wave infrared collimation system according to claim 1, characterized in that: The field of view angle of the medium-wave infrared collimation system is greater than 10°, the central field MTF of the medium-wave infrared collimation system is greater than 0.4 at 30lp / mm, the edge field MTF of the medium-wave infrared collimation system is greater than 0.35 at 30lp / mm, and the distortion is less than 2.5%.

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