阅读说明：本技术 红外波段的偏振分孔径和多光谱成像装置 (Polarization aperture-division and multispectral imaging device for infrared band ) 是由 谢洪波 杨磊 李锦程 苏永鹏 朱猛 于 2020-09-30 设计创作，主要内容包括：本发明涉及偏振分孔径成像和多光谱成像等领域,为了有效抑制背景红外辐射的干扰,提高光学系统探测目标的灵敏度,本发明旨在提出一种红外波段的偏振分孔径和多光谱成像技术,并基于此技术实现多维度红外成像系统。为此,本发明采取的技术方案是,红外波段的偏振分孔径和多光谱成像装置,目标与背景的红外辐射光场首先通过4个大小相等的孔径光阑分为4个通道进行传播,在各个通道内分别经过以不同角度放置的偏振片后进行一次成像；然后再通过旋转式滤光片选择设定的波段以设定的放大倍率二次成像在红外探测器上。本发明主要应用于偏振分孔径成像和多光谱成像场合。(The invention relates to the fields of polarization sub-aperture imaging, multispectral imaging and the like, aims to effectively inhibit the interference of background infrared radiation and improve the sensitivity of an optical system for detecting a target, provides a polarization sub-aperture and multispectral imaging technology of an infrared band, and realizes a multi-dimensional infrared imaging system based on the technology. The technical scheme includes that in the infrared band polarization aperture division and multispectral imaging device, an infrared radiation light field of a target and a background is divided into 4 channels for propagation through 4 aperture diaphragms with the same size, and primary imaging is performed after the infrared radiation light field passes through polaroids placed at different angles in each channel; and then the set wave band is selected through a rotary filter to be secondarily imaged on the infrared detector at the set magnification. The invention is mainly applied to the occasions of polarization aperture division imaging and multispectral imaging.)

1. A polarization aperture-dividing and multispectral imaging device of infrared band, its characteristic is, the infrared radiation light field of the goal and background is divided into 4 channels to spread through 4 aperture diaphragms with equal size at first, carry on the primary imaging after passing the polaroid placed with different angles in every channel separately; and then the set wave band is selected through a rotary filter to be secondarily imaged on the infrared detector at the set magnification.

2. The infrared band polarization, aperture-splitting and multispectral imaging device of claim 1, comprising a polarization imaging subsystem, an image-combining subsystem, a spectral sorting subsystem and a detection device;

the image combination subsystem realizes the function of coupling four intermediate images with different polarization directions to the focal plane detector and has magnification;

the spectrum sorting subsystem is a rotary filter and is used for realizing frequency domain multispectral imaging;

the detection device is a refrigeration type infrared focal plane detector and realizes the detection of an infrared radiation light field;

the polarization imaging subsystem deflects rays through an integrated field lens to realize an image space telecentric light path and realize subsequent pupil connection; each polarizer is placed at an oblique angle in a respective sub-channel.

3. The infrared band polarization, aperture splitting and multispectral imaging device of claim 1, wherein the image combining subsystem is an object-side telecentric structure, and the object height is the image height of the polarization imaging subsystem.

4. The infrared polarization, aperture splitting and multispectral imaging device of claim 1, wherein the spectral sorting subsystem is centered at a plurality of spatially arranged filters of different wavelength bands, and the filters are placed at the first image plane of the image combining subsystem.

5. The infrared band polarization, aperture splitting and multispectral imaging device of claim 1, wherein the object-side telecentric optical path is arranged in the image-combining subsystem to achieve pupil matching between the polarization imaging subsystem and the image-combining subsystem; by setting a certain system magnification, the heights of the diaphragm and the subsequent cold stop of the polarization imaging subsystem meet the object image relationship between the entrance pupil and the exit pupil, so that the height of the light on the cold stop is controlled.

Technical Field

The invention relates to the fields of polarization subaperture imaging, multispectral imaging and the like, and is suitable for a multi-dimensional optical imaging system of an infrared band.

Background

With the development of the photoelectric countermeasure technology, various infrared camouflage measures, particularly the application of infrared camouflage colors, greatly change the radiation characteristics of a target and a background, and seriously affect the recognition capability of an infrared imaging system. The polarization characteristic and the spectral information are new degrees of freedom in infrared imaging, and the target identification capability and the instrument accuracy of an infrared imaging system can be greatly improved. In infrared polarization imaging, the detection and identification capability of an imaging system on a target under a complex background can be improved by utilizing the polarization degree information of target object radiation. For example, in the context of inclement weather, polarization imaging may improve fog penetration of the imaging system; when the imaging system is applied to sea surface detection, polarization imaging can eliminate interference of flare spots and the like. In infrared multispectral imaging, not only can the geometric shape information of an imaging target be obtained, but also the spectral characteristic difference of the target can be identified, so that the contrast between the target and the background is increased, background clutter can be effectively inhibited, true and false targets can be distinguished, and the identification capability of a system target is improved.

Disclosure of Invention

In order to overcome the defects of the prior art, effectively inhibit the interference of background infrared radiation and improve the sensitivity of an optical system for detecting a target, the invention aims to provide a polarization sub-aperture and multispectral imaging technology of an infrared band and realize a multi-dimensional infrared imaging system based on the technology. The technical scheme includes that in the infrared band polarization aperture division and multispectral imaging device, an infrared radiation light field of a target and a background is divided into 4 channels for propagation through 4 aperture diaphragms with the same size, and primary imaging is performed after the infrared radiation light field passes through polaroids placed at different angles in each channel; and then the set wave band is selected through a rotary filter to be secondarily imaged on the infrared detector at the set magnification.

The system consists of a polarization imaging subsystem, an image combination subsystem, a spectrum sorting subsystem and a detection device;

the image combination subsystem realizes the function of coupling four intermediate images with different polarization directions to the focal plane detector and has magnification;

the spectrum sorting subsystem is a rotary filter and is used for realizing frequency domain multispectral imaging;

the detection device is a refrigeration type infrared focal plane detector and realizes the detection of an infrared radiation light field;

the polarization imaging subsystem deflects rays through an integrated field lens to realize an image space telecentric light path and realize subsequent pupil connection; each polarizer is placed at an oblique angle in a respective sub-channel.

The image combination subsystem adopts an object space telecentric structure, and the object height of the image combination subsystem is the image height of the polarization imaging subsystem.

The core of the spectrum sorting subsystem is a plurality of optical filters with different wave bands which are reasonably arranged in space, and the optical filters are placed at a first image surface of the image combination subsystem.

The pupil matching of the polarization imaging subsystem and the image combination subsystem is realized by arranging an object space telecentric optical path in the image combination subsystem; by setting a certain system magnification, the heights of the diaphragm and the subsequent cold stop of the polarization imaging subsystem meet the object image relationship between the entrance pupil and the exit pupil, so that the height of the light on the cold stop is controlled.

The invention has the characteristics and beneficial effects that:

the multi-dimensional infrared imaging system organically integrates polarization sub-aperture imaging and multispectral imaging together, and meanwhile obtains the polarization characteristic and the spectral characteristic of a target object, so that the reliability of obtaining a clear target in a complex environment is effectively improved.

The single detector realizes four-channel detection and ensures the consistency of image surfaces. The infrared radiation light fields of the four channels are respectively imaged on four different positions of the detector, so that the detection surface is full of images, and the aim of keeping four images consistent is fulfilled.

The system adopts a secondary imaging structure, and the exit pupil of the polarization imaging subsystem is imaged at the cold diaphragm of the detector again at a certain multiplying power. Meanwhile, the polarization imaging subsystem adopts the design of an image space telecentric optical path, the image combining subsystem adopts the design of an object space telecentric optical path, and the integral optical system realizes pupil matching, ensures the efficiency of the cold diaphragm by 100 percent and isolates extra heat radiation in a non-scene.

Description of the drawings:

fig. 1 is a schematic view of a multi-dimensional infrared imaging system according to the present invention.

Fig. 2 is a light path diagram of the multi-dimensional infrared imaging system of the present invention.

FIG. 3 is a schematic diagram of a polarization imaging subsystem of the present invention with a polarizer disposed.

FIG. 4 is a layout of key components in the polarization imaging subsystem of the present invention: (a) a polarizing plate; (b) and a field lens.

FIG. 5 is a schematic diagram of a rotating filter in the spectral sorting subsystem of the present invention.

Detailed Description

The technical solution adopted by the invention is as follows:

the multi-dimensional infrared imaging system mainly comprises a polarization imaging subsystem, an image combination subsystem, a spectrum sorting subsystem and a detection device. The polarization imaging subsystem consists of 4 aperture diaphragms with the same size, 4 polaroids with different polarization directions, an imaging objective lens and an integrated field lens, and can realize the function of polarization and aperture division imaging of an infrared radiation light field; the image combination subsystem can realize the function of coupling four intermediate images with different polarization directions to the focal plane detector, and the system sets a certain magnification (for example, 0.5); the core of the spectrum sorting subsystem is a rotary filter, so that the function of frequency domain multispectral imaging can be realized; the detection device selects a refrigeration type infrared focal plane detector, and can realize the function of high-sensitivity detection of the infrared radiation light field.

In the optical design of the polarization imaging subsystem, the integrated field lens deflects and refracts light, so that an image space telecentric light path is realized, and the subsequent pupil connection problem of the optical system is solved. Each polaroid is placed in the corresponding sub-channel in an inclined mode at a certain angle, and the problem of cold reflection caused by high reflectivity of the surface of each polaroid is solved.

The image combination subsystem adopts an object space telecentric structure for pupil matching with the polarization imaging subsystem, and the object height of the system is designed as the image height of the polarization imaging subsystem. In the optimization design process, the cold stop efficiency of the system is 100 percent by controlling the height of the light on the stop.

The core of the spectrum sorting subsystem is a plurality of filters (such as 4) with different wave bands which are reasonably arranged in the space, and the filters are placed at the first image plane of the image combination subsystem. In order to correct chromatic aberration of the system and reduce thermal difference of the system, the optical path system adopts proper materials such as silicon, germanium, zinc sulfide and the like for matching.

The invention has the advantages that:

the multi-dimensional infrared imaging system organically integrates polarization sub-aperture imaging and multispectral imaging together, and meanwhile obtains the polarization characteristic and the spectral characteristic of a target object, so that the reliability of obtaining a clear target in a complex environment is effectively improved.

The single detector realizes four-channel detection and ensures the consistency of image surfaces. The infrared radiation light fields of the four channels are respectively imaged on four different positions of the detector, so that the detection surface is full of images, and the aim of keeping four images consistent is fulfilled.

The system adopts a secondary imaging structure, and the exit pupil of the polarization imaging subsystem is imaged at the cold diaphragm of the detector again at a certain multiplying power. Meanwhile, the polarization imaging subsystem adopts the design of an image space telecentric optical path, the image combining subsystem adopts the design of an object space telecentric optical path, and the integral optical system realizes pupil matching, ensures the efficiency of the cold diaphragm by 100 percent and isolates extra heat radiation in a non-scene.

The present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, the multi-dimensional infrared imaging system of the present invention organically combines the polarization split aperture imaging technology with the multispectral imaging technology. In the optical system, an infrared radiation light field of a target and a background is firstly divided into 4 channels for propagation through 4 aperture diaphragms with the same size, and primary imaging is carried out after the infrared radiation light field passes through polaroids placed at different angles in each channel; then a specific wave band is selected by a rotary filter to be secondarily imaged on the infrared detector at a certain magnification (for example, 0.5).

As shown in fig. 2, the multi-dimensional infrared imaging system of the present invention is mainly composed of a polarization imaging subsystem, an image combining subsystem, a spectrum sorting subsystem and a detection device.

The polarization imaging subsystem of the invention consists of 4 aperture diaphragms with equal size, 4 polaroids with different polarization directions, an imaging objective lens and an integrated field lens, the F number set by the system is matched with a refrigeration type detector, the diameter of an entrance pupil is designed to be large enough to ensure that an infrared radiation light field enters the optical system as much as possible, and the heights of four intermediate images formed by the subsystem are equal. As shown in fig. 2, the polarization imaging subsystem deflects the light rays by the integrated field lens, and realizes an image-space telecentric optical path. As shown in fig. 3, the polarizers in each channel are obliquely arranged at a certain angle, so that the cold reflection problem caused by the high reflectivity of the polarizers is solved.

As shown in fig. 2, the image combining subsystem of the present invention realizes pupil matching between the polarization imaging subsystem and the image combining subsystem by setting an object-side telecentric optical path; by setting a certain system magnification, the heights of the diaphragm and the subsequent cold stop of the polarization imaging subsystem meet the object image relationship between the entrance pupil and the exit pupil, so that the height of light on the cold stop is controlled, and the 100% cold stop efficiency of the system is met.

The key components of the polarization imaging subsystem of the present invention, the four-way polarizer and the integrated field lens, are shown in FIG. 4.

As shown in fig. 5, the spectral sorting subsystem of the present invention adds filters of different wavelength bands to each subsystem, and places the filters on the first surface of the image combining subsystem.

The detection device of the invention adopts a refrigeration type infrared focal plane detector. The detector is equally divided into 4 parts, and the entrance pupil diameter of each part is matched with the prior system optical path to realize pupil matching.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.