A mid-wave cooled infrared detector optical system
By embedding optical lenses in the detector's optical system, compressing the edge light angle or shortening the back intercept, the problems of large size and heavy weight of the optical system are solved, realizing lightweight and high-performance imaging of the mid-wave cooled infrared detector.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUHAN KELIYE TECHNOLOGY CO LTD
- Filing Date
- 2025-09-09
- Publication Date
- 2026-07-31
AI Technical Summary
Existing mid-wave cooled infrared detector optical systems are large and heavy, making it difficult to achieve weight reduction. In addition, the long back intercept of the optical system increases the manufacturing difficulty and cost, limiting its promotion in application scenarios with strict size and weight requirements.
At least one optical lens is embedded in the optical path between the detector's cold stop and the image plane. The embedded optical lens is located inside the Dewar flask, close to the cold stop. A negative lens is used to compress the edge ray angle of the front lens group, or a positive lens is used to shorten the back cutoff of the optical system to ensure the efficiency of the cold stop.
The overall length of the optical system was shortened, the aperture of the front lens was reduced, the size of the optical system was decreased, the imaging quality was improved, and the requirements for lightweighting were met.
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Figure CN224581752U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of infrared optical equipment technology, and more specifically, to a mid-wave cooled infrared detector optical system. Background Technology
[0002] Cooled detectors play a crucial role in numerous fields such as infrared detection, remote sensing imaging, and security monitoring. In the optical system of a cooled detector, the placement of the aperture stop significantly impacts system performance. In existing technologies, to ensure imaging quality and stray light suppression, the aperture stop must be precisely matched to the detector's cold stop position (usually located inside the Dewar flask). This results in a long back intercept, large lens aperture, and difficulty in reducing system size and weight. Furthermore, a greater distance between the cold stop and the image plane increases the projection height of edge field rays onto the lens, forcing a larger front lens aperture. A larger optical system aperture increases the manufacturing difficulty and cost of optical components, while a longer overall length leads to a bulky detector product, hindering lightweight design. This not only causes numerous inconveniences in carrying, installing, and using the detector but also limits its promotion and application in scenarios with strict requirements for size and weight.
[0003] Therefore, how to reduce the size of the optical system and achieve product lightweighting while ensuring the optical performance of the mid-wave cooled detector has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0004] In view of the above-mentioned defects or improvement needs of the existing technology, this utility model provides a mid-wave cooled infrared detector optical system, which can shorten the overall length of the optical system, compress the edge light angle of the front lens, and reduce the aperture of the front lens.
[0005] To achieve the above objectives, according to one aspect of this utility model, a mid-wave cooled infrared detector optical system is provided, comprising a front lens group, a Dewar flask, a cold stop, an embedded optical lens, and an image plane; the Dewar flask has a housing and a window disposed on the housing, and the cold stop, the embedded optical lens, and the image plane are disposed inside the housing; the front lens group, the window, the cold stop, the embedded optical lens, and the image plane are sequentially arranged on the optical axis of the optical system along the incident direction of light; the embedded optical lens is installed in the optical path between the cold stop and the image plane, close to the cold stop; the embedded optical lens is used to further refract and focus the light passing through the cold stop to form an image on the image plane.
[0006] In some implementations, the front lens group is used to process the incident light so that the diameter of the processed beam matches the aperture of the cold stop.
[0007] In some embodiments, the front lens group includes a first optical lens and a second optical lens; the first optical lens is used to initially converge the incident light into parallel light or converging light, and the second optical lens is used to further compress the beam converged by the first optical lens so that the diameter of the compressed beam matches the aperture of the cold stop.
[0008] In some implementations, the front lens group is also used to suppress stray light and reduce noise interference.
[0009] In some embodiments, the front lens group includes a first optical lens and a second optical lens; the first optical lens and the second optical lens are used to suppress stray light.
[0010] In some implementations, the front lens group is also used to correct chromatic aberration and geometric phase aberration of the incident light.
[0011] In some embodiments, the front lens group includes a first optical lens and a second optical lens; the first optical lens and the second optical lens are made of infrared materials with different dispersion characteristics; the first optical lens is an aspherical lens or a spherical lens, used to correct spherical aberration; the second optical lens is an aspherical lens or a spherical lens, used to correct coma.
[0012] In some implementations, the embedded optical lens is one or more.
[0013] In some implementations, the embedded optical lens is a negative lens, used to compress the edge ray angle of the front lens group and reduce the aperture of the front lens group; or the embedded optical lens is a positive lens, used to shorten the back intercept of the optical system.
[0014] In some embodiments, when there are multiple embedded optical lenses, a portion of the embedded optical lenses are negative lenses used to compress the edge ray angle of the front lens group and reduce the aperture of the front lens group; another portion of the embedded optical lenses are positive lenses used to shorten the back intercept of the optical system.
[0015] Overall, compared with the prior art, the above-described technical solution conceived by this utility model has the following beneficial effects: at least one optical lens is embedded in the optical path between the detector cold stop and the image plane, and the embedded optical lens is located inside the Dewar flask and close to the cold stop; when the embedded optical lens is a negative lens, it is used to compress the edge light angle of the front lens group and reduce the aperture of the front lens group; when the embedded optical lens is a positive lens, it is used to shorten the back intercept of the optical system, thereby shortening the overall length of the optical system; the light transmission aperture of the embedded optical lens matches the size of the cold stop, ensuring 100% cold stop efficiency. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the mid-wave cooled infrared detector optical system according to an embodiment of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered exemplary in nature and not restrictive.
[0018] like Figure 1 As shown, the mid-wave cooled infrared detector optical system of this embodiment includes a front lens, a Dewar flask, a cold stop 5, an embedded optical lens 3, and an image plane 8. The Dewar flask has a housing 6 and a window 4 disposed on the housing 6. The cold stop 5, the embedded optical lens 3, and the image plane 8 are disposed inside the housing 6. The front lens, window 4, cold stop 5, embedded optical lens 3, and image plane 8 are sequentially arranged on the optical axis of the optical system along the incident direction of light. The cold stop 5 is fixedly installed at a predetermined position inside the housing 6, the image plane 8 is disposed at an imaging position inside the housing 6, and the embedded optical lens 3 is installed in the optical path between the cold stop 5 and the image plane 8, close to the cold stop 5. The embedded optical lens 3 is stably installed inside the housing 6 by a fixed bracket.
[0019] The front lens group processes the incident light from object plane 9, ensuring that the diameter of the processed beam precisely matches the aperture of the cold stop 5. The front lens group also suppresses stray light and reduces noise interference. Furthermore, it corrects chromatic aberration and geometric phase aberration in the incident light. The incident light, processed by the front lens group, enters the Dewar flask through window 4, passes through the cold stop 5, and is further refracted and focused by the embedded optical lens 3, accurately forming an image on image plane 8.
[0020] In some embodiments, there are one or more embedded optical lenses. In some embodiments, the embedded optical lens is a negative lens, used to compress the edge ray angle of the front lens group and reduce the aperture of the front lens group. In some embodiments, the embedded optical lens is a positive lens, used to shorten the back intercept of the optical system. In some embodiments, when there are multiple embedded optical lenses, some of the embedded optical lenses are negative lenses, used to compress the edge ray angle of the front lens group and reduce the aperture of the front lens group; other embedded optical lenses are positive lenses, used to shorten the back intercept of the optical system.
[0021] The aperture of the embedded optical lens is matched with the size of the cold stop to ensure 100% cold stop efficiency. The embedded optical lens is made of materials suitable for the mid-infrared band, and its radius of curvature and thickness are precisely calculated and processed according to the design requirements of the optical system.
[0022] like Figure 1 As shown, in some embodiments, the front lens group includes a first optical lens 1 and a second optical lens 2. In some embodiments, the first optical lens 1 is used to initially converge the incident light into parallel or converging light, and the second optical lens 2 is used to further compress the beam converged by the first optical lens 1, so that the diameter of the compressed beam precisely matches the aperture of the cold stop 5. In some embodiments, the first optical lens 1 and the second optical lens 2 are used to further suppress stray light, preventing it from entering the Dewar flask and reducing noise interference at the source. In some embodiments, the first optical lens 1 and the second optical lens 2 are made of infrared materials with different dispersion characteristics; for example, the material of the first optical lens 1 is germanium, and the material of the second optical lens 2 is silicon. Furthermore, the first optical lens 1 is an aspherical lens or a spherical lens to correct spherical aberration, and the second optical lens is an aspherical lens or a spherical lens to correct coma.
[0023] After actual testing, the improved structure of this embodiment reduces the volume of the optical system of the mid-wave cooled infrared detector by 25% compared with the prior art, shrinks the volume of the optical lens by 28%, and significantly improves the imaging quality, thus meeting the requirements of relevant application scenarios for lightweight and high-performance detectors.
[0024] This invention embeds at least one optical lens in the optical path between the detector's cold stop and the image plane. The embedded optical lens is located inside the Dewar flask and close to the cold stop. When the embedded optical lens is a negative lens, it is used to compress the edge light angle of the front lens group and reduce the aperture of the front lens group. When the embedded optical lens is a positive lens, it is used to shorten the back intercept of the optical system, thereby shortening the overall length of the optical system. The light transmission aperture of the embedded optical lens matches the size of the cold stop to ensure 100% cold stop efficiency.
[0025] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.
[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.
[0027] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more (two or more) executable instructions for implementing a particular logical function or process. Furthermore, the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functionality involved.
[0028] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A mid-wave refrigeration-type infrared detector optical system, characterized by, The system includes a front lens, a Dewar flask, a cold stop, an embedded optical lens, and an image plane. The Dewar flask has a housing and a window disposed on the housing. The cold stop, the embedded optical lens, and the image plane are disposed within the housing. The front lens, the window, the cold stop, the embedded optical lens, and the image plane are sequentially arranged on the optical axis of the optical system along the incident direction of light. The embedded optical lens is mounted on the optical path between the cold stop and the image plane, close to the cold stop. The embedded optical lens is used to further refract and focus the light passing through the cold stop to form an image on the image plane.
2. The midwave cryogenic infrared detector optical system of claim 1, wherein, The front lens group is used to process the incident light so that the diameter of the processed beam matches the aperture of the cold stop.
3. The midwave cryogenic infrared detector optical system of claim 2, wherein, The front lens group includes a first optical lens and a second optical lens; the first optical lens is used to initially converge the incident light into parallel light or converging light, and the second optical lens is used to further compress the beam converged by the first optical lens so that the diameter of the compressed beam matches the aperture of the cold stop.
4. The midwave cryogenic infrared detector optical system of claim 2, wherein, The front lens group is also used to suppress stray light and reduce noise interference.
5. The midwave cryogenic infrared detector optical system of claim 4, wherein, The front lens group includes a first optical lens and a second optical lens; the first optical lens and the second optical lens are used to suppress stray light.
6. The midwave cryogenic infrared detector optical system of claim 4, wherein, The front lens group is also used to correct chromatic aberration and geometric phase aberration of the incident light.
7. The midwave cryogenic infrared detector optical system of claim 6, wherein, The front lens group includes a first optical lens and a second optical lens; the first optical lens and the second optical lens are made of infrared materials with different dispersion characteristics; the first optical lens is an aspherical lens or a spherical lens, used to correct spherical aberration; the second optical lens is an aspherical lens or a spherical lens, used to correct coma.
8. The mid-wave refrigeration-type infrared detector optical system according to any one of claims 1 to 7, wherein, The embedded optical lens may be one or more.
9. The midwave cryogenic infrared detector optical system of claim 8, wherein, The embedded optical lens is a negative lens, used to compress the edge light angle of the front lens group and reduce the aperture of the front lens group; or the embedded optical lens is a positive lens, used to shorten the back cutoff of the optical system.
10. The midwave cryogenic infrared detector optical system of claim 8, wherein, When there are multiple embedded optical lenses, a portion of the embedded optical lenses are negative lenses, used to compress the edge light angle of the front lens group and reduce the aperture of the front lens group; another portion of the embedded optical lenses are positive lenses, used to shorten the back intercept of the optical system.