Delta-shaped spliced detector cold screen for exit pupil-free matching infrared optical system
By designing a Z-shaped spliced detector cold screen for matching infrared optical systems without exit pupils, and using a multi-layer cold screen structure and a baffle to separate the field of view, the problem of suppressing radiation stray light in the optical machine is solved and the problem is achieved. It effectively suppresses the radiation of the detector and reduces the cost of the optical-mechanical structure.
Patent Information
- Application Number
- CN202411244512.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-01-21
AI Technical Summary
The prior art is difficult to effectively suppress stray light radiated in the optical machine in the infrared optical system without outgoing pupil matching, resulting in an increase in the three-dimensional angle of the optical machine structure to the detector, increasing the cost of lens cooling.
Design a kind of -shaped stitching detector cold screen, adopts a multi -layer cold screen structure, each layer of cold screen corresponding sub -detector position is set up, and the baffle is set between two adjacent cold screen to separate the sub -detector Vision. The cold -screen structure is superimposed with pyramids, using high -heat -conducting molybdenum copper alloy materials, and plating on the outer surface with nickel plating inner surfaces.
Through the cold -screen structure, it can effectively reduce the three -dimensional corner of the detector, reduce the radiation mixed light in the light machine, reduce the demand for light mechanical refrigeration, and reduce the cost of the lens light machine structure.
Smart Images
Figure CN119334475A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of space optical remote sensors, and in particular relates to a cold screen of a herringbone spliced detector for a pupil-free matching infrared optical system. Background Art
[0002] With the development of optical remote sensing technology, the demand for high resolution and wide bandwidth of infrared detection cameras has led to an increasingly larger field of view of infrared optical systems and an increasingly larger scale of infrared array detectors. Currently, the scale of infrared array detectors is generally increased by splicing short array devices in a triangular shape.
[0003] Infrared cameras have stray light emitted from the optical machine. Matching the camera exit pupil with the detector cold stop is one of the effective means to suppress the radiation from the optical machine. As the optical field of view increases, it becomes increasingly difficult to match the optical system exit pupil with the cold stop. On the one hand, matching the exit pupil with the cold stop of a large-field-of-view infrared optical system will cause a serious deterioration in the uniformity of the illumination on the image plane; on the other hand, matching the exit pupil with the cold stop of a large-field-of-view infrared optical system requires that the distance between the exit pupil and the image plane is very large, which increases the height of the infrared dewar, significantly increases the heat leakage and weight of the dewar, and makes it difficult to control the temperature inside the dewar very low. Therefore, large-field-of-view infrared optical systems are generally designed without exit pupil matching, which makes it difficult for the detector assembly to suppress the radiation from the optical machine.
[0004] The cold screens disclosed in CN116356382, CN115360205 and CN114705297 are all traditional single-opening cold screen structures, which are not suitable for internal radiation suppression of infrared optical systems without exit pupil matching. Such a structure has very limited suppression of internal radiation of the optical machine, which transfers the pressure of internal radiation suppression of the optical machine to lens cooling, increasing costs such as power consumption and weight. Summary of the invention
[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and provide a herringbone spliced detector cold screen for a pupil-free infrared optical system, which greatly reduces the radiated stray light in the optomechanical structure.
[0006] The object of the present invention is achieved through the following technical scheme: a herringbone spliced detector cold screen for a pupil-free matching infrared optical system, comprising: a plurality of layers of cold screens; wherein each layer of cold screen has a light-through hole corresponding to the position of each sub-detector; a baffle is arranged between two adjacent layers of cold screens, and the baffle separates the field of view corresponding to each sub-detector.
[0007] In the above-mentioned herringbone spliced detector cold shield for the non-exit pupil matching infrared optical system, the number of baffles arranged between two adjacent layers of cold shields is one less than the number of sub-detectors.
[0008] In the above-mentioned herringbone spliced detector cold shield for the pupil-free matching infrared optical system, the plane direction of each baffle is perpendicular to the surface direction of the cold shield; one end of each baffle is arranged at the center of the distance between two adjacent light holes of the upper layer of cold shield, and the other end of each baffle is arranged at the center of the distance between two adjacent light holes of the lower layer of cold shield.
[0009] In the above-mentioned herringbone spliced detector cold shield for the non-exit pupil matching infrared optical system, the multiple layers of cold shields are stacked in a pyramid shape.
[0010] In the above-mentioned cold shield of the herringbone spliced detector for the non-exit pupil matching infrared optical system, the lateral size xn of the light hole of the nth layer of the cold shield is:
[0011] xn=x+Ln×tanθ;
[0012] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, x is the width of the sub-detector, n is the number of layers, and n is a positive integer.
[0013] In the above-mentioned cold shield of the herringbone spliced detector for the non-exit pupil matching infrared optical system, the longitudinal dimension yn of the light hole of the nth layer of cold shield is:
[0014] yn=y+Ln×tanθ;
[0015] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, y is the length of the sub-detector, n is the number of layers, and n is a positive integer.
[0016] In the above-mentioned herringbone spliced detector cold shield for the non-exit pupil matching infrared optical system, the spacing dxn between two adjacent light holes in the horizontal direction of the n-th layer of cold shield is:
[0017] dxn=dx-Ln×tanθ;
[0018] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dx is the distance between two adjacent sub-detectors in the lateral direction, n is the number of layers, and n is a positive integer.
[0019] In the above-mentioned herringbone spliced detector cold shield for the non-exit pupil matching infrared optical system, the distance dyn between two adjacent light holes in the longitudinal direction of the n-th layer of cold shield is:
[0020] dyn = dy - Ln × tanθ;
[0021] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dy is the distance between two adjacent sub-detectors in the longitudinal direction, n is the number of layers, and n is a positive integer.
[0022] In the above-mentioned cold screen of the herringbone spliced detector for the non-exit pupil matching infrared optical system, the distance dy between two adjacent sub-detectors in the longitudinal direction is:
[0023] dy=y-2yy;
[0024] Where y is the length of the sub-detector and yy is the overlap length between sub-detectors.
[0025] In the above-mentioned herringbone spliced detector cold shield for the pupil-free matching infrared optical system, each layer of the cold shield is made of a molybdenum-copper alloy material with high thermal conductivity, the outer surface of each layer of the cold shield is gold-plated, and the inner surface of each layer of the cold shield is nickel-plated.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] (1) The present invention can suppress radiation in an optical machine of an infrared optical system without exit pupil matching, thereby reducing the demand for cooling of the optical machine;
[0028] (2) The cold shield structure adopted in the present invention is suitable for the inscribed long linear array spliced detector of the infrared optical system without exit pupil matching, and a multi-level cold shield design method is provided. Compared with the single long strip opening form of the cold shield of the conventional long linear array detector, the present invention can effectively reduce the solid angle of the lens optomechanical structure to the detector, thereby greatly reducing the radiated stray light in the optomechanical structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:
[0030] Figure 1 Schematic diagram of a long linear array herringbone splicing detector provided by an embodiment of the present invention;
[0031] Figure 2 is a schematic diagram of an opening of an n-th level cold shield provided by an embodiment of the present invention;
[0032] Figure 3 Schematic diagram of the relationship between the opening dimensions of the cold shield provided in an embodiment of the present invention (with two levels as an example);
[0033] Figure 4 It is a schematic diagram of the cold shield structure provided by an embodiment of the present invention (with two stages as an example). DETAILED DESCRIPTION
[0034] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0035] Taking advantage of the characteristics of the detector's T-shaped splicing and using a fine-structured cold shield to improve the detector assembly's efficiency in suppressing internal radiation in the optomechanical system is the key to solving the problem of radiation suppression in infrared optical systems without exit pupil matching.
[0036] The present embodiment provides a herringbone spliced detector cold shield for a pupil-free matching infrared optical system, comprising: a plurality of layers of cold shields; wherein each layer of cold shield has a light-through hole corresponding to the position of each sub-detector; and a baffle is arranged between two adjacent layers of cold shields, and the baffle separates the fields of view corresponding to each sub-detector.
[0037] The number of baffles arranged between two adjacent layers of cold screens is one less than the number of sub-detectors; the plane direction of each baffle is perpendicular to the surface direction of the cold screen; one end of each baffle is arranged at the center of the distance between two adjacent light holes of the upper layer of cold screen, and the other end of each baffle is arranged at the center of the distance between two adjacent light holes of the lower layer of cold screen.
[0038] The multi-layer cold screens are stacked in a pyramid style.
[0039] The lateral size xn of the light hole of the nth layer of cold screen is:
[0040] xn=x+Ln×tanθ;
[0041] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, x is the width of the sub-detector, n is the number of layers, and n is a positive integer.
[0042] The longitudinal dimension yn of the light-through hole of the nth layer of cold screen is:
[0043] yn=y+Ln×tanθ;
[0044] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, y is the length of the sub-detector, n is the number of layers, and n is a positive integer.
[0045] The distance dxn between two adjacent light holes in the horizontal direction of the nth layer of cold screen is:
[0046] dxn=dx-Ln×tanθ;
[0047] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dx is the distance between two adjacent sub-detectors in the lateral direction, n is the number of layers, and n is a positive integer.
[0048] The distance dyn between two adjacent light holes in the longitudinal direction of the nth layer of cold screen is:
[0049] dyn = dy - Ln × tanθ;
[0050] Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dy is the distance between two adjacent sub-detectors in the longitudinal direction, n is the number of layers, and n is a positive integer.
[0051] The distance dy between two adjacent sub-detectors in the longitudinal direction is:
[0052] dy=y-2yy;
[0053] Where y is the length of the sub-detector and yy is the overlap length between sub-detectors.
[0054] Each layer of cold screen is made of high thermal conductivity molybdenum-copper alloy material, with gold plating on the outer surface and black nickel plating on the inner surface.
[0055] The cold screen is a multi-level structure for long-line array T-shaped spliced detectors in pupil-free matching infrared optical systems. Each layer of the cold screen has a rectangular opening at the corresponding T-shaped spliced sub-detector field of view. The cold screen is made of high thermal conductivity molybdenum-copper alloy material, with gold-plated outer surface and blackened inner surface.
[0056] The detectors are spliced in a long linear array in a triangular shape, with a certain distance between the sub-detectors. The matched infrared optical system without pupil matching means that the light of the field of view corresponding to each sub-detector is also separated by a certain distance in front of the detector. By adding baffles between these intervals, the solid angle of the optomechanical structure to each sub-detector can be greatly reduced, thereby reducing the optomechanical internal radiation reaching the detector.
[0057] like Figure 1 , is a schematic diagram of a long linear array T-shaped spliced detector of the present invention, wherein a plurality of linear array self-detectors are arranged in a T-shaped staggered manner and spliced into a long linear array detector.
[0058] like Figure 2 , is a schematic diagram of the opening of a single-layer cold screen of the present invention. The single-layer cold screen opens light holes corresponding to the spliced sub-detectors, and the size and spacing of the light holes are determined by the image side aperture angle of the optical system and the distance from the cold screen to the detector.
[0059] like Figure 3, is a schematic diagram for calculating the opening size of each layer of the multi-layer cold shield. The opening size of the nth layer of cold shield has a lateral dimension xn=x+Ln×tanθ, and a longitudinal dimension yn=y+Ln×tanθ, where Ln is the distance between the cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, x is the width of the single-chip linear array detector, and y is the length of the single-chip linear array detector; the lateral spacing of the cold shield opening dxn=dx-Ln×tanθ, and the longitudinal spacing of the cold shield opening dyn=dy-Ln×tanθ, where dx is the lateral spacing of the single-chip linear array detector, dy is the longitudinal spacing of the single-chip linear array detector (generally slightly smaller than y), dY=y-2yy, and yy is the overlap length between sub-detectors. The calculation methods for the openings and opening spacing of the remaining layers of cold shields are similar.
[0060] like Figure 4 , is a schematic diagram of a two-stage cold shield. There are baffles perpendicular to the cold shield surface between the layers of the multi-stage cold shield. The baffles are located at the center of the aperture spacing to separate the fields of view corresponding to each sub-detector. The cold shield is made of high thermal conductivity molybdenum-copper alloy material to achieve low-temperature cooling close to the infrared focal plane temperature. The outer surface is gold-plated to reduce the emissivity, and the inner surface is blackened to increase the absorption rate.
[0061] Traditional detector cold shields are only applicable to the case where the optical system exit pupil matches the cold shield, and cannot solve the problem of internal radiation suppression in optical systems without exit pupil matching; this embodiment can achieve radiation suppression in the optical machine of infrared optical systems without exit pupil matching, reducing the demand for cooling of the optical machine; the cold shield structure adopted in this embodiment is suitable for the herringbone long linear array spliced detector of the infrared optical system without exit pupil matching, and a multi-stage cold shield design method is given. Compared with the single long strip opening form of the conventional long linear array detector cold shield, it can effectively reduce the solid angle of the lens optical machine structure to the detector, thereby greatly reducing the radiated stray light in the optical machine structure.
[0062] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.
Claims
1. A cold shield for a detector with a herringbone splicing for a pupil-free matching infrared optical system, characterized in that include: Multi-layer cold screen; among them, Each layer of cold screen has light holes corresponding to the positions of each sub-detector; A baffle is arranged between two adjacent layers of cold screens, and the baffle separates the fields of view corresponding to each sub-detector.
2. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The number of baffles arranged between two adjacent layers of cold shields is one less than the number of sub-detectors.
3. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 2, characterized in that: The plane direction of each baffle is perpendicular to the cold screen surface direction; One end of each baffle is arranged at the center of the distance between two adjacent light-transmitting holes of the upper layer of cold screen, and the other end of each baffle is arranged at the center of the distance between two adjacent light-transmitting holes of the lower layer of cold screen.
4. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The multi-layer cold screens are stacked in a pyramid style.
5. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The lateral size xn of the light hole of the nth layer of cold screen is: xn=x+Ln×tanθ; Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, x is the width of the sub-detector, n is the number of layers, and n is a positive integer.
6. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The longitudinal dimension yn of the light-through hole of the nth layer of cold screen is: yn=y+Ln×tanθ; Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, y is the length of the sub-detector, n is the number of layers, and n is a positive integer.
7. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The distance dxn between two adjacent light holes in the horizontal direction of the nth layer of cold screen is: dxn=dx-Ln×tanθ; Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dx is the distance between two adjacent sub-detectors in the lateral direction, n is the number of layers, and n is a positive integer.
8. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: The distance dyn between two adjacent light holes in the longitudinal direction of the nth layer of cold screen is: dyn = dy - Ln × tanθ; Wherein, Ln is the distance between the nth cold shield and the detector photosensitive surface, θ is the aperture angle of the optical system, dy is the distance between two adjacent sub-detectors in the longitudinal direction, n is the number of layers, and n is a positive integer.
9. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 8, characterized in that: The distance dy between two adjacent sub-detectors in the longitudinal direction is: dy=y-2yy; Where y is the length of the sub-detector and yy is the overlap length between sub-detectors.
10. The cold shield of the detector with a herringbone splicing for the infrared optical system without exit pupil matching according to claim 1, characterized in that: Each layer of cold screen is made of molybdenum-copper alloy material, the outer surface of each layer of cold screen is gold-plated, and the inner surface of each layer of cold screen is nickel-plated.