Total reflection type visible-infrared dual-channel common-view-field imaging optical system
By adopting a total reflective relay system, the problems of large weight, chromatic aberration and high material cost of the transmission relay system are solved, and lightweight, chromatic aberration-free wide-spectral segment imaging is achieved, and the material preparation cost is reduced.
Patent Information
- Application Number
- CN202411425467.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2025-04-25
AI Technical Summary
The existing transmission relay system has problems such as large weight, chromatic aberration and high material preparation cost in visible infrared multi-channel imaging systems, making it difficult to achieve lightweight, wide-spectrum imaging and low-cost materials.
The total reflective visible infrared dual-channel common field imaging optical system is adopted, and the reflective relay system is used to realize a lightweight design under the same imaging performance. The reflection law is used to eliminate chromatic aberration, and the low-cost mirror material is selected.
The camera weight reduction under the same imaging performance conditions is achieved, which eliminates the chromatic aberration problem in wide-spectral imaging, and reduces the cost of material preparation and avoids the risk of foreign restriction of material acquisition.
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Abstract
Description
Technical Field
[0001] The present disclosure relates to an optical lens system, and in particular to an optical system of a visible and infrared multi-channel imaging lens. Background Art
[0002] Space optical remote sensors have gone through the development process of refraction, catadioptric, and total reflection. Reflective optical systems are widely used in space optical remote sensors because of their light weight and easier processing. For visible infrared multi-channel imaging systems with an entrance pupil diameter greater than 500mm, infrared relay lenses are currently only implemented using a transmissive optical system. Under the transmissive system, the entire camera will have a large weight, increasing the launch cost. Due to the chromatic aberration characteristics of the transmissive system, its imaging spectrum is limited to a relatively narrow range, and it is impossible to achieve wide-band imaging from short waves to long waves. If wide-band imaging is required, multiple groups of infrared relay lens groups must be used, which will greatly increase the weight of the camera or the launch cost. For large-aperture infrared lenses, high-quality infrared lens materials will become very expensive. During the blanking stage, the refractive index uniformity of the infrared lens material will change due to differences in the manufacturing process, resulting in different refractive indices of the material at different positions of the lens, which will have a great impact on the imaging performance.
[0003] The only manufacturing difficulty for reflectors is to control their mirror geometry and surface shape, but this is also the manufacturing difficulty of infrared lenses. In other words, the reflective infrared relay system greatly reduces the design difficulty and manufacturing cost of visible infrared multi-channel imaging optical systems. Summary of the invention
[0004] In order to solve the problem of heavy weight of the transmission relay system, the present disclosure provides a fully reflective visible infrared dual-channel common field of view imaging optical system. By adopting a reflective relay system, the optical system can achieve a smaller camera weight under the condition of equal imaging performance.
[0005] In order to solve the chromatic aberration problem of the transmission relay system under wide-spectrum imaging, the present disclosure provides a fully reflective visible-infrared dual-channel common-field-of-view imaging optical system. By adopting a reflective relay system, wide-spectrum imaging follows the law of reflection. Under this law, the imaging light path is independent of the wavelength, so there is no chromatic aberration.
[0006] In order to solve the problem of high material preparation cost or even inaccessibility under large-aperture imaging of transmission relay system, the present invention provides a fully reflective visible infrared dual-channel common field imaging optical system, which adopts a reflective relay system, has many types of reflector materials, low preparation cost, and can be prepared domestically for large-aperture reflector materials without the risk of being restricted by foreign countries. It has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 It is a structural schematic diagram of a fully reflective visible infrared dual-channel common field of view imaging optical system.
[0008] Figure 2 It is the MTF curve of the visible imaging channel of a fully reflective visible-infrared dual-channel common-field imaging optical system.
[0009] Figure 3 It is the MTF curve of the infrared imaging channel of a fully reflective visible infrared dual-channel common field imaging optical system.
[0010] Figure 4 It is a distortion grid of the visible imaging channel of a fully reflective visible-infrared dual-channel common-field imaging optical system.
[0011] Figure 5 It is a distortion grid of the infrared imaging channel of a fully reflective visible infrared dual-channel common field imaging optical system. DETAILED DESCRIPTION
[0012] The present invention is described in detail below with reference to the accompanying drawings. Figure 1 The present invention provides a structure for describing the contents in detail.
[0013] The present invention is a visible and infrared dual-channel imaging system, wherein the main reflector, the second reflector and the third reflector are dual-channel common imaging optical components. A color separation mirror is used to separate the visible imaging channel and the infrared imaging channel for spectral imaging, and the infrared channel uses multiple reflectors for aberration correction and effective focal length design, and a free surface is used to perform comprehensive correction on astigmatism, coma, spherical aberration and distortion of the infrared imaging channel, so as to obtain an MTF curve close to the diffraction limit.
[0014] The parameters of each component in a fully reflective visible infrared dual-channel common field imaging optical system are shown in the following table:
[0015]
[0016]
[0017] The infrared second reflector is a free-form surface, and its vector height is calculated as follows:
[0018] Where z is the vector height of the free-form surface, c is the vertex curvature, k is the quadratic aspheric coefficient, and r is the distance between the point on the free-form surface and the vertex. is the high-order aspheric coefficient, and Ai is the zernikes coefficient.
[0019]
[0020] The infrared third reflector is an even-order aspheric surface, and its sagittal height is calculated as follows:
[0021] Where z is the vector height of the free-form surface, c is the vertex curvature, k is the quadratic aspheric coefficient, and r is the distance between the point on the free-form surface and the vertex. is the high-order aspheric coefficient.
[0022]
[0023] The infrared fifth reflector is an even-order aspheric surface, and its sagittal height is calculated as follows:
[0024] Where z is the vector height of the free-form surface, c is the vertex curvature, k is the quadratic aspheric coefficient, and r is the distance between the point on the free-form surface and the vertex. is the high-order aspheric coefficient.
Claims
1. A fully reflective visible infrared dual-channel common field imaging optical system, characterized in that: The system consists of a main reflector, a second reflector, a folding mirror, a third reflector, a color separation mirror, an infrared first reflector, an infrared second reflector, an infrared third reflector, an infrared fourth reflector, an infrared fifth reflector and a cold screen window.
2. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 1 is characterized in that The main reflector, the second reflector, the folding mirror, the third reflector, and the dichroic mirror constitute a visible light imaging channel. The main reflector, the second reflector, the folding mirror, the third reflector, the dichroic mirror, the first infrared reflector, the second infrared reflector, the third infrared reflector, the fourth infrared reflector, the fifth infrared reflector, and the cold screen window constitute an infrared imaging channel.
3. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 1, characterized in that Light from any field of view enters the optical system, is split by the color separation plate, and the visible and infrared channels simultaneously image the object in the field of view. That is, after imaging by this optical system, the visible spectrum image and infrared spectrum image of the object can be obtained simultaneously.
4. The total reflection type visible infrared dual channel common field imaging optical system according to claim 1, characterized in that The infrared relay system is a total reflection system composed of an infrared first reflector, an infrared second reflector, an infrared third reflector, an infrared fourth reflector, and an infrared fifth reflector.
5. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 1 or 4, characterized in that The infrared relay system includes a quadratic aspheric surface, an even-order aspheric surface and a free-form surface. The infrared first reflector and the infrared fourth reflector are quadratic aspheric surfaces. The infrared third reflector and the infrared fifth reflector are even-order aspheric surfaces. The infrared second reflector is a free-form surface.
6. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 1, 4 or 5, characterized in that The infrared third reflector, the infrared fourth reflector and the infrared fifth reflector in the infrared relay system are a coaxial reflection system.
7. The total reflection type visible infrared dual channel common field imaging optical system according to claim 4, characterized in that The number of reflectors in the infrared relay system is not limited to the above five reflectors, and the number of reflectors can be increased or decreased.
8. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 4, characterized in that The types of aspheric surfaces in the infrared relay system reflector are not limited to quadratic aspheric surfaces, free-form surfaces and even-order aspheric surfaces.
9. The total reflection type visible infrared dual-channel common field imaging optical system according to claim 1, characterized in that The main reflector has a light clearance diameter greater than 100 mm.
10. The total reflection type visible infrared dual channel common field imaging optical system according to claim 3, characterized in that Visible and infrared imaging channels are not limited to dual channels, but can also be used for triple channel and multi-channel imaging.