Large-view-field photoelectric imaging system for aerial camera

Abstract

The invention relates to a large-view-field photoelectric imaging system for an aerial camera, and belongs to the technical field of photoelectric instruments. Comprising a single-lens system, a splicing detector focal plane assembly and a supporting frame. The number of the single-lens systems is two, the two single lenses are fixed on the supporting frame at a certain angle, and each single-lens system is provided with a group of lenses and a reflector; the number of the spliced detector focal plane assemblies is two, and each spliced detector focal plane assembly comprises a CMOS detector and a spliced focal panel; the CMOS detectors are fixed on the splicing focal panel, an imaging light beam is divided into two paths by the reflecting mirror and is respectively imaged on the two CMOS detectors, and the camera photoelectric imaging system designed in the mode has the advantages of being free of moving parts, simple in lens design, large in one-time imaging field angle, high in resolution ratio, capable of greatly improving the reliability of the camera and prolonging the service life of the camera and the like. And meanwhile, the spliced focal plane is completely fixed on the internal structure of the camera, so that the imaging positioning precision can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of optoelectronic instruments, and in particular relates to a large-field optoelectronic imaging system for an aerial camera. Background Art

[0002] Aerial photography, as a means of aerial optoelectronic imaging, has been an important part of the field of aerial imaging since its inception. Designing high-resolution and large-field-of-view cameras has become an inevitable trend in the development of aerial optoelectronic imaging technology. However, the size of CMOS image sensors cannot be made very large due to process limitations, so the size of CMOS image sensors has become the main factor limiting the field of view of cameras. Field-of-view stitching technology is the key to solving the problem of large field of view. At present, field-of-view stitching mainly includes mechanical stitching of imaging devices, multi-lens multi-array stitching, and single-lens multi-array stitching. Mechanical stitching of imaging devices is to arrange multiple image sensors closely on the image plane. The advantage of mechanical stitching is that the optical system of the camera using mechanical stitching is relatively simple. The disadvantage is that the finished CMOS components have a packaging structure and a certain geometric size. The actual pixel is larger than the effective pixel. Therefore, directly stitching two CMOS together will produce a gap in the middle, resulting in a shooting blind area during imaging and loss of image information. In order to achieve seamless stitching, the traditional method is to remove the package of a single CMOS chip and stitch the effective pixels in sequence, but this method is complex and costly and is rarely used. Multi-lens multi-array CMOS stitching is that each CMOS chip uses an independent optical system, which is physically "bundled" to form an equivalent camera system with a large imaging area. Its advantage is simple implementation, but its disadvantage is bulky structure. Single-lens multi-array CMOS stitching is that multiple CMOS devices use the same set of lenses. Since the multi-array CMOS jointly forms the focal plane, the optical system is more complex, and the installation accuracy of each array CMOS is very high. The more CMOS chips there are, the more difficult it is to install and adjust. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The technical problem to be solved by the present invention is to provide a large-field-of-view optoelectronic imaging system for aerial cameras. When the size of existing CMOS image sensors cannot be enlarged due to process limitations, an optoelectronic imaging system with a large field of view, small size and simple optical system is designed.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the present invention provides a large-field-of-view optoelectronic imaging system for an aerial camera, comprising: a single-lens system, a spliced ​​detector focal plane assembly, and a support frame;

[0007] The single-lens system is provided with two sets, and the two sets of single lenses are fixed on the support frame at a certain angle to each other, and each system is provided with a set of lenses and a reflector;

[0008] The spliced ​​detector focal plane components are provided with two groups, and each group of the spliced ​​detector focal plane components comprises: a CMOS detector and a spliced ​​focal plane panel;

[0009] The CMOS detector is fixed on the spliced ​​focus panel, and the imaging light beam is divided into two paths by a reflector, and the images are respectively formed on two CMOS detectors;

[0010] The light of ground object information is incident on the corresponding camera lens through two windows, and is imaged on the photosensitive surfaces of four CMOS detectors after transmission and reflection mirror splitting. After photoelectric conversion by the CMOS detector, the optical imaging information of the ground object target is converted into digital image information, thereby completing the photography with the camera's field of view expanded several times.

[0011] The two single lenses are staggered in space, with the fixed node as the rotation axis, arranged symmetrically, the optical axis planes of the single lenses are parallel, and the pointing angle of the fixed lens is set to ±16.5°;

[0012] The single lens is fixed on the supporting frame through a lens fixing frame, thereby fixing the pointing angle of the single lens.

[0013] Wherein, an adjustment pad is provided at the connection between the CMOS detector and the spliced ​​focus panel;

[0014] The coplanarity of the photosensitive surfaces of the two CMOS detectors is ensured by grinding the adjustment pads.

[0015] Each lens is equipped with two imaging modules, and the imaging surface is designed to have 152 overlapping pixels.

[0016] Among them, the focal length of each lens is designed to be 126mm and the relative aperture is designed to be 6.

[0017] Among them, the lens fixing frame is made of 7A09 aviation material to achieve a single-lens field of view angle of ≥35° and a double-lens field of view angle of ≥62° after splicing.

[0018] The package size of the CMOS detector is set to 38.75×27.75 mm, the pixel size is 4.6 μm, and the number of pixels on the image plane is 8424×6032.

[0019] (III) Beneficial effects

[0020] Compared with the prior art, the present invention has the following beneficial effects: the camera optoelectronic imaging system designed in this way has no moving parts, and has a simple lens design, a large field of view for single-shot imaging, and a high resolution, which greatly improves the reliability and service life of the camera. At the same time, since the splicing focal plane is completely fixed in the internal structure of the camera, it is beneficial to improve the imaging positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing the structure of the optoelectronic imaging system of the present invention;

[0022] Figure 2 This is a diagram showing the structure of a single-lens optical system of the present invention;

[0023] Figure 3 A transmission function diagram is designed for the optical system for the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, content, and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0025] This embodiment provides a large-field-of-view optoelectronic imaging system for an aerial camera, comprising: a single-lens system, a spliced ​​detector focal plane assembly, and a support frame;

[0026] The single-lens system is provided with two sets, and the two sets of single lenses are fixed on the support frame at a certain angle to each other, and each system is provided with a set of lenses and a reflector;

[0027] The two lenses are staggered in space, with the fixed node as the rotation axis, arranged symmetrically, the lens optical axis planes are parallel, and the fixed lens pointing angle is set to ±16.5°;

[0028] The spliced ​​detector focal plane components are provided with two groups, and each group of the spliced ​​detector focal plane components comprises: a CMOS detector and a spliced ​​focal plane panel;

[0029] The CMOS detector is fixed on the spliced ​​focus panel, and the imaging light beam is divided into two paths by a reflector, and the images are respectively formed on two CMOS detectors;

[0030] The light of ground object information is incident on the corresponding camera lens through two windows, and is imaged on the photosensitive surfaces of four CMOS detectors after transmission and reflection mirror splitting. After photoelectric conversion by the CMOS detector, the optical imaging information of the ground object target is converted into digital image information, thereby completing the photography with the camera's field of view expanded several times.

[0031] Wherein, dual splicing imaging is performed through the two lenses, and the lens pointing angle is fixed by a lens fixing frame.

[0032] Wherein, an adjustment pad is provided at the connection between the CMOS detector and the spliced ​​focus panel;

[0033] The coplanarity of the photosensitive surfaces of the two CMOS detectors is ensured by grinding the adjustment pads.

[0034] Each lens is equipped with two imaging modules, and the imaging surface is designed to have 152 overlapping pixels. The actual focal plane length is about 76.8mm, and the corresponding ground width is about 3047m (at an altitude of 5km).

[0035] Among them, the focal length of each lens is designed to be 126mm, the relative aperture is designed to be 6, and the optical design transfer function (average) is ≥0.43 (108lp / mm).

[0036] Among them, the lens fixing frame is made of 7A09 aviation material, achieving a single-lens field of view angle of ≥35°, a double-lens field of view angle of ≥62° after splicing, a accommodating width of ≥6km (flight altitude 5000m), and a pixel resolution of ≤0.19m (flight altitude 5000m).

[0037] The package size of the CMOS detector is set to 38.75×27.75 mm, the pixel size is 4.6 μm, and the number of pixels on the image plane is 8424×6032.

[0038] The design performance indicators of the large field of view optoelectronic imaging system for aerial cameras are shown in Table 1.

[0039] Table 1 Design parameters of optoelectronic imaging system

[0040]

[0041]

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A large-field-of-view optoelectronic imaging system for an aerial camera, characterized in that: include: Single lens system, spliced ​​detector focal plane assembly, support frame; The single-lens system is provided with two sets, and the two sets of single lenses are fixed on the support frame at a certain angle to each other, and each system is provided with a set of lenses and a reflector; The spliced ​​detector focal plane components are provided with two groups, and each group of the spliced ​​detector focal plane components comprises: a CMOS detector and a spliced ​​focal plane panel; The CMOS detector is fixed on the spliced ​​focus panel, and the imaging light beam is divided into two paths by a reflector, and the images are respectively formed on two CMOS detectors; The light of ground object information is incident on the corresponding camera lens through two windows, and is imaged on the photosensitive surfaces of four CMOS detectors after transmission and reflection mirror splitting. After photoelectric conversion by the CMOS detector, the optical imaging information of the ground object target is converted into digital image information, thereby completing the photography with the camera's field of view expanded several times.

2. The large-field-of-view optoelectronic imaging system for an aerial camera according to claim 1, characterized in that: The two single lenses are staggered front and back in space, symmetrically arranged with the fixed node as the rotation axis, and the pointing angle of the fixed lens is set to ±16.5°; The single lens is fixed on the supporting frame through a lens fixing frame, thereby fixing the pointing angle of the single lens.

3. The large-field-of-view optoelectronic imaging system for an aerial camera according to claim 1, characterized in that: An adjustment pad is provided at the connection between the CMOS detector and the spliced ​​focus panel; The coplanarity of the photosensitive surfaces of the two CMOS detectors is ensured by grinding the adjustment pads.

4. The large-field-of-view optoelectronic imaging system for an aerial camera according to claim 1, characterized in that: Each lens is equipped with two imaging modules, and the imaging surface is designed to have 152 pixels overlapping.

5. The large-field-of-view optoelectronic imaging system for an aerial camera according to claim 1, characterized in that: The focal length of each lens is designed to be 126mm and the relative aperture is designed to be 6.

6. The large-field-of-view optoelectronic imaging system for an aerial camera according to claim 2, characterized in that: The lens fixing frame is made of 7A09 aviation material to achieve a single-lens field of view angle of ≥35° and a double-lens field of view angle of ≥62° after splicing.

7. The large-field-of-view electro-optical imaging system for an aerial camera according to claim 1, characterized in that: The package size of the CMOS detector is set to 38.75×27.75 mm, the pixel size is 4.6 μm, and the number of pixels on the image plane is 8424×6032.

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