Multi-aperture lobster eye optical system

Abstract

Compared with a traditional lobster eye optical system, the multi-aperture lobster eye optical system has the advantages that the number of light spot arms is remarkably increased, the difficulty of imaging positioning in an edge view field is remarkably reduced through the improvement, and the positioning precision and reliability are improved; in addition, a central aperture optical subsystem is placed in the center to image a target object, so that the problem that a lobster eye optical system cannot clearly image the target can be improved; generally speaking, the rhombic lobster eye lens has obvious advantages in imaging performance and practical application, the difficulty of imaging positioning in an edge field of view is obviously reduced, the positioning precision and reliability are improved, and when the angle between the rhombic lobster eye lens and a detector is changed, the angle of the rhombic lobster eye lens is changed, and the positioning precision and reliability are improved. The original imaging definition and detail performance are kept, and the stability of the imaging quality is high.

Description

Technical Field

[0001] The invention belongs to the technical field of optical elements, and in particular relates to a multi-aperture lobster eye optical system. Background Art

[0002] In traditional high-performance imaging optical systems, in order to achieve a wide field of view and high imaging quality at the same time, the existing practice is to expand the system's entrance pupil diameter to reduce the F number. This method can improve the resolution and working distance of the system, but it also leads to increased costs and increased system complexity. Specifically, in order to reduce off-axis aberrations such as astigmatism and chromatic aberration caused by a large field of view, it is often necessary to introduce more optical elements or use specially designed optical components, which not only increases the weight and volume of the optical system, but also significantly increases the manufacturing cost.

[0003] The lobster-eye optical system has a wide field of view and a wide applicable spectral range due to its unique reflective stacking imaging characteristics. This feature allows it to play a role not only in the field of high-energy rays such as small-wavelength rays, but also in the visible light, infrared and terahertz bands. In addition, when the ratio of the square cross-section of each small unit that makes up the optical system to its aperture length is kept at a low level, the system can achieve high resolution at the arc second level. Each small eye of the lobster-eye system is arranged along the radius of the sphere, and its axis is aligned with the radius of the sphere and points to the center of the sphere. This structural feature means that the system has no fixed optical axis, which gives the lobster-eye optical system its remarkable characteristic of a wide field of view.

[0004] Researching and developing this new bionic multi-aperture imaging technology with resolution selectivity can significantly reduce the complexity of optical imaging systems. It is particularly suitable for aerial remote sensing and monitoring, which have strict requirements for large field of view, high resolution, and fast image transmission and processing speed. Through this technology, not only can common problems in wide field of view imaging be effectively handled, but also new heights in cost, efficiency and performance can be achieved.

[0005] However, it is well known that the field of view and imaging resolution of an optical system are contradictory. Traditional design methods make it difficult to achieve all three of them, which usually results in complex system structure, increased weight, and increased costs, which is not conducive to the actual use of the system. Summary of the invention

[0006] To solve the above problems, the present invention provides a multi-aperture lobster eye optical system that can simultaneously locate and image a target, and also significantly reduces the difficulty of imaging and positioning in the edge field of view, thereby improving the accuracy and reliability of positioning.

[0007] A multi-aperture lobster-eye optical system, comprising a lobster-eye optical subsystem and a central aperture optical subsystem having a common image plane on a central axis, wherein the lobster-eye optical subsystem is a hemispherical structure formed by arranging a plurality of quadrangular pyramid microchannels, and a through hole for installing the central aperture optical subsystem is reserved in the middle of the hemispherical structure;

[0008] The cross section, upper surface and lower surface of the quadrangular pyramid microchannel are all rhombuses with curvature, and the inner wall surfaces of the quadrangular pyramid microchannel are all reflective planes; when the target point light source only enters the field of view of the lobster eye optical subsystem, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, so that three light spot arms intersecting at one point for positioning the target point light source are formed on the image plane; when the target point light source enters the field of view of the lobster eye optical subsystem and the central aperture optical subsystem at the same time, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, and the central aperture optical subsystem is used to image the incident light emitted by the target point light source, so that an image of the target point light source and three light spot arms intersecting at one point for positioning the target point light source are simultaneously formed on the image plane.

[0009] Furthermore, any four-sided pyramid microchannel reflects the incident light emitted by the target point light source to the image plane along three paths:

[0010] Part of the light is reflected on one set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the first light spot arm; another part of the light is reflected on another set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the second light spot arm; the last part of the light is reflected on the four inner surfaces of the rhombus, and the light in the short diagonal direction of the rhombus finally converges on the image plane to form the third light spot arm.

[0011] Furthermore, the target point light source is positioned according to the length change, width change and rotation angle change of the three light spot arms.

[0012] Furthermore, the method for positioning the target point light source through three light spot arms is:

[0013] When the length of the spot arm at the lower right corner increases and the width decreases, and the length of the spot arm at the upper left corner decreases and the width increases, it means that the target point light source moves to the upper left corner;

[0014] When the length of the spot arm at the lower left corner increases and the width decreases, and the length of the spot arm at the upper right corner decreases and the width increases, it means that the target point light source moves to the upper right corner;

[0015] When the length of the spot arm in the upper right corner increases and the width decreases, and the length of the spot arm in the lower left corner decreases and the width increases, it means that the target point light source moves to the lower left corner;

[0016] When the length of the light spot arm in the upper left corner increases and the width decreases, and the length of the light spot arm in the lower right corner decreases and the width increases, it means that the target point light source moves to the lower right corner;

[0017] When the length of the light spot arm formed by the light in the short diagonal direction of the rhombus gradually decreases, it means that the target point light source is approaching the multi-aperture lobster eye optical system;

[0018] When the width of the three light spot arms gradually increases, it means that the target point light source gradually moves away from the multi-aperture lobster eye optical system;

[0019] When the angles of the three light spot arms rotate, it means that the target point light source also rotates.

[0020] Furthermore, the lens structure of the central aperture optical subsystem is a five-piece structure located in the mid-wave infrared band, with a total length of 265 mm, a focal length of 200 mm, a back focal length of 90 mm, a relative aperture of f / 2, and a half field of view angle of 7.5°.

[0021] Furthermore, the total field of view is 40° and the equivalent focal length is 265 mm.

[0022] Furthermore, the method for determining the curvature radius R of the hemispherical structure formed by the lobster eye optical subsystem is as follows:

[0023] Assume that the incident point of any incident light ray DE formed by the target point light source D on any tetrahedral microchannel is E, the exit point of the incident light ray on the tetrahedral microchannel after multiple reflections in the tetrahedral microchannel is F, the imaging point of the incident light ray DE on the image plane is A, the center point of the curved surface of the hemispherical structure formed by the lobster eye optical subsystem is O, the foot of the perpendicular of point F to the line segment OD is B, a tangent is drawn to the outer surface of the lobster eye optical subsystem at point E, and the intersection of the tangent and the line segment OD is recorded as C;

[0024] According to the geometric relationship, on the basis of the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the curvature radius R of the hemispherical structure formed by the lobster eye optical subsystem needs to meet the following constraints:

[0025]

[0026] Wherein, L1 is the distance from the first mirror to the last mirror of the central aperture optical subsystem, L2 is the semi-diameter of the central aperture optical subsystem, FB is the perpendicular line segment between point F and line segment OD, ∠FOA is the cone vertex angle of the tetrahedral microchannel, ∠FAB is the acute angle between the light emitting direction FA and the central axis OD, and ∠AFO is the angle between the light emitting direction FA and the line segment FO;

[0027] According to the geometric relationship, on the basis of the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the constraint conditions that the ratio λ of the length to the width of any four-sided pyramid microchannel of the lobster eye optical subsystem needs to satisfy are as follows:

[0028]

[0029] Wherein, γ is the apex angle of the tetrahedral microchannel, and ∠FAO is the obtuse angle between the light emission direction FA and the central axis OD.

[0030] Beneficial effects:

[0031] 1. The present invention provides a multi-aperture lobster-eye optical system. Compared with the traditional lobster-eye optical system, the new lobster-eye optical system significantly increases the number of light spot arms. This improvement significantly reduces the difficulty of imaging positioning in the edge field of view and improves the accuracy and reliability of positioning. In addition, the central aperture optical subsystem is placed in the center to image the target object, which can improve the problem that the lobster-eye optical system itself cannot clearly image the target. In general, the diamond lobster-eye lens of the present invention shows obvious advantages in imaging performance and practical applications. It not only significantly reduces the difficulty of imaging positioning in the edge field of view and improves the accuracy and reliability of positioning, but also can maintain the original imaging clarity and detail performance when the angle between the diamond lobster-eye lens and the detector changes, and the imaging quality is highly stable.

[0032] 2. The present invention provides a multi-aperture lobster eye optical system, which can effectively acquire and identify characteristic information of a light source by analyzing changes in the focal arm during imaging and its corresponding angle information. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the multi-aperture lobster eye optical system of the present invention.

[0034] Figure 2 It is a schematic structural diagram of the lobster eye optical subsystem after the hole is dug in the present invention.

[0035] Figure 3 It is a schematic diagram of positioning the light spot in the central field of view of the novel lobster eye optical system of the present invention.

[0036] Figure 4 It is a schematic diagram of the structure of the central aperture optical system.

[0037] Figure 5 This is a schematic diagram of imaging a point light source at the edge of the field of view.

[0038] Figure 6 It is a schematic diagram of positioning and imaging a point light source in the field of view.

[0039] Figure 7 This is a schematic diagram of the imaging of a point light source at the center of the field of view by the new lobster-eye optical system.

[0040] Figure 8 This is a schematic diagram of the light propagation model of the new lobster eye optical system. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0042] The present invention aims to resolve the contradiction between a large field of view and high resolution in traditional optical systems. Based on the structure of the lobster eye, a new multi-aperture lobster eye optical system with a special structure is provided, which can achieve richer image information for any point light source within a large field of view, obtain spectral information of key targets in the field of view, and effectively improve the accuracy of detection. While maintaining a wide field of view, the high-resolution optical components in the central area can be used to achieve detailed observation of specific areas and long-distance target recognition. This multi-aperture technology has important application value in optical system design. It can not only improve the utilization rate of light energy and optimize imaging quality, but also significantly reduce the weight and complexity of the optical system, and reduce the demand for data transmission and processing, thereby reducing costs.

[0043] Specifically, Figure 1 As shown, a multi-aperture lobster-eye optical system provided by the present invention includes a lobster-eye optical subsystem and a central aperture optical subsystem having a common image plane on a central axis, wherein the lobster-eye optical subsystem is a hemispherical structure formed by arranging a plurality of quadrangular pyramid microchannels, and a through hole for installing the central aperture optical subsystem is reserved in the middle of the hemispherical structure, such as Figure 2 As shown;

[0044] The cross section, upper surface and lower surface of the quadrangular pyramid microchannel are all rhombuses with curvature, and the inner wall surfaces of the quadrangular pyramid microchannel are all reflective planes; when the target point light source only enters the field of view of the lobster eye optical subsystem, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, so that three light spot arms intersecting at one point for positioning the target point light source are formed on the image plane; when the target point light source enters the field of view of the lobster eye optical subsystem and the central aperture optical subsystem at the same time, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, and the central aperture optical subsystem is used to image the incident light emitted by the target point light source, so that an image of the target point light source and three light spot arms intersecting at one point for positioning the target point light source are simultaneously formed on the image plane.

[0045] Based on this, the detection process of the present invention can be briefly described as follows: the basic working mode of the system is high-sensitivity detection of a large field of view in the periphery and high-resolution imaging of the central local area. First, when the target enters the field of view, the multi-aperture lobster eye optical system captures the light radiated by the target, such as Figure 5 As shown in Figure 1. The light is reflected in the microchannel of the spherical shell unit and finally forms a positioning image on the photodetector. By analyzing the imaging law of the light source on the diamond lobster eye lens, the image signal of the target can be processed to obtain the position information of the target. When the field of view of the target relative to the multi-aperture lobster eye optical system is less than 15°, as shown in Figure 1. Figure 6 When entering the field of view of the central aperture optical system, the target is imaged while being positioned, as shown in Figure 7 As shown, a C-shaped annular light spot can be obtained on the receiving surface.

[0046] It should be noted that the lens structure of the central aperture optical subsystem of the present invention is a five-piece structure, located in the mid-wave infrared band, with a total length of 265mm, a focal length of 200mm, a back focal length of 90mm, a relative aperture of f / 2, and a half field of view of 7.5°. The specific structure is as follows: Figure 4 It should be noted that, in the process of optimizing the design of the central aperture optical subsystem using optical design software, a custom optimization operand can be added to optimize the aberration in the optical system, and the optimized index value can be set. By analyzing the optical system and changing the parameter structure of the optical system, the set target can be gradually approached.

[0047] For the new lobster eye optical system, a boss base unit structure with an angle of 60° is first established, and a curve array is performed on the corresponding curve to form a complete new lobster eye optical system. Alternatively, a single quadrangular pyramid structure with rhombus-shaped upper and lower surfaces is first established, and a curve array is performed on the quadrangular pyramid structure in two directions to finally obtain a new lobster eye optical system. These two modeling methods can accurately reproduce the structure and optical properties of the new lobster eye optical system. For the multi-aperture lobster eye optical system, the total field of view is 40°. The total length of the designed central aperture optical system is 265 mm. According to the special structural characteristics of the new lobster eye optical system, the equivalent focal length of the new lobster eye optical system is 265 mm.

[0048] That is to say, the new lobster eye optical system provided by the present invention changes the existing lobster eye microchannel structure, designs the upper and lower surfaces of the quadrangular pyramid microchannel into a rhombus with curvature, and makes a curve array according to the arc of the spherical surface, and finally obtains a new lobster eye optical system with a rhombus structure. The central aperture optical system is placed in the central area, and high-resolution imaging can be performed while positioning the target. The inner wall surface of the quadrangular pyramid is a plane with reflective properties. When the light enters the microchannel, due to the particularity of the quadrangular pyramid microchannel structure, the light will be divided into multiple paths due to the difference in angles. Among them, a part of the light will be reflected on the inner surfaces of the rhombus that are parallel to each other, and finally converge on the image plane. The other part of the light is reflected on the four inner surfaces of the rhombus. Due to the angle of the light in the long diagonal direction, the light will be dispersed, and it is difficult to form a light spot. In the short diagonal direction, the light will not be deflected at too large an angle, and finally converge on the image plane. When it reaches the image plane, three obvious light spot arms will be formed, such as Figure 3 shown.

[0049] Compared with the existing technology, the new lobster eye optical system proposed in the present invention can significantly improve the problem of reduced imaging information of the spot when the existing lobster eye lens is imaged in the edge field of view. Through the optimized design of the lobster eye lens structure, the system has many advantages: when the imaging spot of the diamond lobster eye lens changes in the field of view angle, the length and width of the focal arm of the imaging spot and the energy concentration of the central diffuse spot will also change. In addition, when the distance between the point light source and the diamond lobster eye lens changes, the imaging spot will also change regularly. The many advantages of the diamond lobster eye lens make it possible to capture images from multiple angles while analyzing the richer feature information of the spot to facilitate the judgment of the information of the point light source. A central aperture optical system is placed in the center of the new lobster eye optical system to image the objects in the field of view, so the positioning and imaging functions of the multi-aperture lobster eye optical system can be performed simultaneously.

[0050] Furthermore, any four-sided pyramid microchannel reflects the incident light emitted by the target point light source to the image plane along three paths:

[0051] Part of the light is reflected on one set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the first light spot arm; another part of the light is reflected on another set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the second light spot arm; the last part of the light is reflected on the four inner surfaces of the rhombus, and the light in the short diagonal direction of the rhombus finally converges on the image plane to form the third light spot arm.

[0052] It should be noted that the diamond lobster eye lens will show significantly different imaging effects from the traditional lobster eye lens at different field angles and distances. This unique imaging characteristic helps to obtain and identify the detailed characteristics of the light source through image information. When the light source moves to the upper left corner, the display effect of the diamond lobster eye imaging system will change. Specifically, the length of the focal arm in the lower right corner increases and the width decreases, while the length of the focal arm in the upper left corner decreases and the width increases. This characteristic information of the change in focal arm length and width can be used to determine the position information of the light source and its related characteristics. Therefore, by analyzing the changes in the focal arm in the imaging and its corresponding angle information, the characteristic information of the light source can be effectively acquired and identified.

[0053] Based on this, the present invention locates the target point light source according to the length change, width change and rotation angle change of the three light spot arms, as follows:

[0054] When the length of the spot arm at the lower right corner increases and the width decreases, and the length of the spot arm at the upper left corner decreases and the width increases, it means that the target point light source moves to the upper left corner;

[0055] When the length of the spot arm at the lower left corner increases and the width decreases, and the length of the spot arm at the upper right corner decreases and the width increases, it means that the target point light source moves to the upper right corner;

[0056] When the length of the spot arm in the upper right corner increases and the width decreases, and the length of the spot arm in the lower left corner decreases and the width increases, it means that the target point light source moves to the lower left corner;

[0057] When the length of the light spot arm in the upper left corner increases and the width decreases, and the length of the light spot arm in the lower right corner decreases and the width increases, it means that the target point light source moves to the lower right corner;

[0058] When the length of the light spot arm formed by the light in the short diagonal direction of the rhombus gradually decreases, it means that the target point light source is approaching the multi-aperture lobster eye optical system;

[0059] When the width of the three light spot arms gradually increases, it means that the target point light source gradually moves away from the multi-aperture lobster eye optical system;

[0060] When the angles of the three light spot arms rotate, it means that the target point light source also rotates.

[0061] That is to say, when the positions of the detector and the multi-aperture lobster-eye optical system are fixed, changes in the distance from the light source will affect the image produced by the multi-aperture lobster-eye optical system. Within a certain moving distance of the light source, the image can maintain a clear spot structure, which indicates the existence of an optical depth of field. When the distance between the point light source and the multi-aperture lobster-eye optical system decreases, the lengths of the two focal arms corresponding to the shorter diagonal lines of the multi-aperture lobster-eye optical system gradually decrease and eventually disappear completely. On the contrary, when the distance between the light source and the multi-aperture lobster-eye optical system increases, the widths of the three focal arms in the image will continue to increase, eventually leading to the dissipation of the spot and the image cannot remain clear. When the light source is at infinity, the focal spot effect of the imaging is obvious, and the two spot arms on the upper right and lower left show a certain degree of bifurcation, which clearly demonstrates the distribution characteristics of the focal spot.

[0062] When the relative angular position between the multi-aperture lobster-eye optical system and the detector changes, for example, when the multi-aperture lobster-eye optical system is rotated by a certain angle, the imaging of the light source after passing through the multi-aperture lobster-eye optical system will be affected. Specifically, after the imaging process of the point light source in the diamond lobster eye, the angle of the imaging spot formed will also change. The angles of the three spot arms of the diamond lobster eye lens have all rotated. However, despite the change in the focal arm angle, the clarity of the image has not been affected, and the original clarity and detail performance have been maintained. This shows that the diamond lobster eye has good control over the stability of the imaging quality during the rotation process.

[0063] It should be noted that the advantages of the present invention using three light spot arms for positioning are reflected in the following aspects:

[0064] 1. Redundancy: The positioning of the intersection of the three spot arms provides redundant information. If the data of one spot arm is erroneous or interfered, the remaining two spot arms can still provide enough information to determine the location of the target. This redundancy improves the reliability of the system.

[0065] 2. Higher accuracy: Three beam arms can better define a point in space, especially when there are measurement errors. The intersection of two beam arms may be inaccurate due to errors, while the intersection of three beam arms can improve accuracy by solving the optimal value between multiple intersections.

[0066] 3. Error detection and correction: By comparing the intersection points defined by the three spot arms, outliers or errors can be identified. When the intersection points of the three spot arms are far apart, it can be inferred that there may be a problem with the measurement of a spot arm, which can be corrected in time.

[0067] 4. Multi-directional positioning: The three light spot arms can come from different directions, providing a comprehensive perspective. Compared with two straight light spot arms that can only intersect in one plane, the intersection of three light spot arms allows positioning in more complex environments.

[0068] 5. Geometric stability: The intersection of the three light spot arms provides a more stable solution geometrically, especially when dealing with complex terrain or environment, which can effectively reduce the impact caused by obstacles or interference.

[0069] Furthermore, the present invention combines the designed central aperture optical system with the bionic lobster eye optical system structure to complete the overall design of the multi-aperture lobster eye optical system, which requires:

[0070] 1) The lobster eye optical subsystem and the central aperture optical subsystem perform imaging through the edge channel and the central channel respectively, and the light of the two channels forms an image on a common image plane after passing through the sub-optical systems.

[0071] 2) The overall length of the central aperture optical subsystem is designed not to block the light, and the images are collected through the edge channels. Similarly, the microchannels of the lobster eye optical system cannot block the light of the central aperture optical system.

[0072] 3) The field of view angles of the central channel and the edge channel should be reasonably allocated during the design process, and the aperture of the central aperture optical subsystem should not be too large to interfere with the imaging of the lobster eye microchannel at the boundary line of the field of view.

[0073] The half-field-of-view angle range of the lobster-eye optical subsystem should be greater than the half-field-of-view range of the central aperture optical subsystem and there should be no field-of-view loss problem between the two optical subsystems. Therefore, a circular through hole is used to place the central aperture optical subsystem, which imposes restrictions on the edge height of the central aperture optical subsystem. In view of this, the maximum diameter and overall length of the central aperture optical subsystem at the circular through hole should be subject to the following constraints:

[0074] like Figure 8 As shown, the microchannel closest to the central aperture optical subsystem is given. Assume that the incident point of any incident light ray DE formed by the target point light source D on any tetrahedral microchannel is E, and the exit point of the incident light ray on the tetrahedral microchannel after multiple reflections in the tetrahedral microchannel is F. The imaging point of the incident light ray DE on the image plane is A, the center point of the curved surface of the hemispherical structure formed by the lobster eye optical subsystem is O, the foot of the perpendicular of point F to the line segment OD is B, and a tangent line is drawn to the outer surface of the lobster eye optical subsystem at point E, and the intersection of the tangent line and the line segment OD is recorded as C;

[0075] ∠DEC=α1. The angle will change when reflecting in the microchannel. According to the geometric relationship, the angle α2 of the second reflection is calculated as:

[0076]

[0077] The exit angle α after n reflections n for:

[0078] α n =α1-(n-1)β

[0079] Among them, β is the cone vertex angle ∠EOD of the lobster eye optical system, and n is the number of reflections in the microchannel of the new lobster eye optical system on the boundary of the structure. According to the formula, the light incident on the microchannel of the lobster eye optical system will not be able to pass through the microchannel due to too many reflections and will be emitted in the opposite direction.

[0080] After combining the boundary conditions of the lobster eye light incidence, it can be analyzed that:

[0081] ∠FAB=90°+(n-1)β+∠FOA-α1

[0082] The lobster eye optical system and the central optical system have a common image plane on the central axis. Therefore, based on the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the curvature radius R of the hemispherical structure formed by the lobster eye optical subsystem needs to satisfy the following constraints according to the geometric relationship:

[0083]

[0084] Wherein, L1 is the distance from the first mirror to the last mirror of the central aperture optical subsystem, L2 is the semi-diameter of the central aperture optical subsystem, FB is the perpendicular line segment between point F and line segment OD, ∠FOA is the cone vertex angle of the tetrahedral microchannel, ∠FAB is the acute angle between the light emitting direction FA and the central axis OD, and ∠AFO is the angle between the light emitting direction FA and the line segment FO;

[0085] According to the geometric relationship, on the basis of the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the constraint condition that the ratio λ of the length to the width of any tetrahedral microchannel of the lobster eye optical subsystem needs to satisfy is as follows:

[0086]

[0087] Wherein, γ is the apex angle of the tetrahedral microchannel, and ∠FAO is the obtuse angle between the light emission direction FA and the central axis OD.

[0088] Furthermore, in the process of optimizing the design of the central aperture optical subsystem of the present invention using optical design software, a custom optimization operand is added to optimize the aberration in the optical system. The optimized index value is set, and the optical system is analyzed and the parameter structure of the optical system is changed to gradually approach the set target. In the process of optimization, the field of view angle, aperture size, and overall length allocated to the two different channels are continuously adjusted to balance the influence of the cooperation of the multi-aperture optical system on the imaging quality. The specific steps are as follows:

[0089] 1) Set the optical system parameters and boundary conditions of the initial structure, and manually change the initial parameters of the initial structure such as the working spectrum, field of view angle, entrance pupil diameter, etc.

[0090] 2) The curvature radius, center thickness and other parameters of the optical glass in the lens of the central aperture optical system are set as variables, and the total length of the optical system is controlled by limiting the optical parameters in special constraints.

[0091] 3) Add the boundary conditions of structural parameters such as back focal length limit and edge height, and use the global optimization module in code V to further optimize the optical system, from which the appropriate optical system structure can be selected for step-by-step optimization until the design requirements are met.

[0092] 4) After optimizing the lens using the virtual refractive index, use the glass fit macro file in the optical design software to select the virtual glass. After selecting the real glass model, the imaging quality of the optical system will decline. You can use the glass expert function to further optimize the design of each piece of glass.

[0093] In summary, the present invention has the following advantages over the prior art:

[0094] 1. The multi-aperture lobster-eye optical system achieves the functions of high resolution in the center and large field of view at the edge in a brand-new way. It can not only effectively deal with common problems in wide-field imaging, but also significantly reduce the complexity of the optical imaging system.

[0095] 2. The multi-aperture lobster-eye optical system can simultaneously locate and image the target, which significantly reduces the difficulty of imaging and positioning in the edge field of view, and improves the accuracy and reliability of positioning. At the same time, the three-arm image of the lobster-eye imaging is highly sensitive, and the position information change of the light source can be reflected in the imaging spot feature information on the detector. When the angle between the diamond-shaped lobster-eye lens and the detector changes, the imaging spot on the detector will also rotate accordingly, and can maintain the original clarity and detail performance, and the imaging quality is highly stable.

[0096] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may certainly make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A multi-aperture lobster eye optical system, characterized in that: It includes a lobster eye optical subsystem and a central aperture optical subsystem having a common image plane on the central axis, wherein the lobster eye optical subsystem is a hemispherical structure formed by arranging a plurality of quadrangular pyramid microchannels, and a through hole for installing the central aperture optical subsystem is reserved in the middle of the hemispherical structure; The cross section, upper surface and lower surface of the quadrangular pyramid microchannel are all rhombuses with curvature, and the inner wall surfaces of the quadrangular pyramid microchannel are all reflective planes; when the target point light source only enters the field of view of the lobster eye optical subsystem, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, so that three light spot arms intersecting at one point for positioning the target point light source are formed on the image plane; when the target point light source enters the field of view of the lobster eye optical subsystem and the central aperture optical subsystem at the same time, each quadrangular pyramid microchannel is used to divide the incident light emitted by the target point light source into three paths and reflect it to the image plane, and the central aperture optical subsystem is used to image the incident light emitted by the target point light source, so that an image of the target point light source and three light spot arms intersecting at one point for positioning the target point light source are simultaneously formed on the image plane.

2. A multi-aperture lobster eye optical system as claimed in claim 1, characterized in that: The three paths along which any tetrahedral microchannel reflects the incident light from the target point light source to the image plane are: Part of the light is reflected on one set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the first light spot arm; another part of the light is reflected on another set of mutually parallel inner surfaces of the rhombus, and finally converges on the image plane to form the second light spot arm; the last part of the light is reflected on the four inner surfaces of the rhombus, and the light in the short diagonal direction of the rhombus finally converges on the image plane to form the third light spot arm.

3. The multi-aperture lobster eye optical system according to claim 1, characterized in that: The target point light source is positioned according to the changes in length, width and rotation angle of the three light spot arms.

4. A multi-aperture lobster eye optical system as claimed in claim 1 or 3, characterized in that: The method for positioning the target point light source through three light spot arms is: When the length of the spot arm at the lower right corner increases and the width decreases, and the length of the spot arm at the upper left corner decreases and the width increases, it means that the target point light source moves to the upper left corner; When the length of the spot arm at the lower left corner increases and the width decreases, and the length of the spot arm at the upper right corner decreases and the width increases, it means that the target point light source moves to the upper right corner; When the length of the spot arm in the upper right corner increases and the width decreases, and the length of the spot arm in the lower left corner decreases and the width increases, it means that the target point light source moves to the lower left corner; When the length of the light spot arm in the upper left corner increases and the width decreases, and the length of the light spot arm in the lower right corner decreases and the width increases, it means that the target point light source moves to the lower right corner; When the length of the light spot arm formed by the light in the short diagonal direction of the rhombus gradually decreases, it means that the target point light source is approaching the multi-aperture lobster eye optical system; When the width of the three light spot arms gradually increases, it means that the target point light source gradually moves away from the multi-aperture lobster eye optical system; When the angles of the three light spot arms rotate, it means that the target point light source also rotates.

5. The multi-aperture lobster eye optical system according to claim 1, characterized in that: The lens structure of the central aperture optical subsystem is a five-piece structure located in the mid-wave infrared band, with a total length of 265mm, a focal length of 200mm, a back focal length of 90mm, a relative aperture of f / 2, and a half field of view angle of 7.5°.

6. The multi-aperture lobster eye optical system according to claim 1, characterized in that: The total field of view is 40° and the equivalent focal length is 265mm.

7. The multi-aperture lobster eye optical system according to claim 1, characterized in that: The method for determining the curvature radius R of the hemispherical structure formed by the lobster eye optical subsystem is as follows: Assume that the incident point of any incident light ray DE formed by the target point light source D on any tetrahedral microchannel is E, the exit point of the incident light ray on the tetrahedral microchannel after multiple reflections in the tetrahedral microchannel is F, the imaging point of the incident light ray DE on the image plane is A, the center point of the curved surface of the hemispherical structure formed by the lobster eye optical subsystem is O, the foot of the perpendicular of point F to the line segment OD is B, a tangent is drawn to the outer surface of the lobster eye optical subsystem at point E, and the intersection of the tangent and the line segment OD is recorded as C; According to the geometric relationship, on the basis of the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the curvature radius R of the hemispherical structure formed by the lobster eye optical subsystem needs to meet the following constraints: Wherein, L1 is the distance from the first mirror to the last mirror of the central aperture optical subsystem, L2 is the semi-diameter of the central aperture optical subsystem, FB is the perpendicular line segment between point F and line segment OD, ∠FOA is the cone vertex angle of the tetrahedral microchannel, ∠FAB is the acute angle between the light emitting direction FA and the central axis OD, and ∠AFO is the angle between the light emitting direction FA and the line segment FO; According to the geometric relationship, on the basis of the common image plane of the lobster eye optical subsystem and the central aperture optical subsystem, the constraint condition that the ratio λ of the length to the width of any tetrahedral microchannel of the lobster eye optical subsystem needs to satisfy is as follows: Wherein, γ is the apex angle of the tetrahedral microchannel, and ∠FAO is the obtuse angle between the light emission direction FA and the central axis OD.

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