A method for spherically assembling detector chips

Abstract

The application discloses a kind of spherical surface splicing methods of detector chip, comprising the following steps: according to the distance d of detector chip center and focal spherical surface center, the azimuth angle φ of chip center and the zenith angle θ of chip center, determine the position of detector chip center and the normal direction of detector chip in splicing coordinate system;According to the position of mark point on detector chip in chip coordinate system, and the conversion relationship of chip coordinate system to splicing coordinate system, calculate the position of mark point in splicing coordinate system;Calculate the overall shape envelope and make corresponding support structure;Detector chip is installed in support structure corresponding position;Repeat the above steps until all detector chip splicing is in place, complete the spherical surface splicing of detector chip.The detector chip array spliced by the application is closer to the focal spherical surface of lobster-eye optical system, compared with traditional splicing method, reduces the defocus caused by the curvature of lobster-eye optical system focal surface, and improves the imaging quality.

Description

Technical Field

[0001] This invention relates to the field of lobster eye telescope technology, and in particular to a spherical splicing method for detector chips. Background Technology

[0002] The Lobster Eye Telescope is a large-field-of-view X-ray imaging system with a unique structure, named for its microchannel plate structure resembling the compound eye of a lobster. This optical system has broad application prospects in astronomical detection, space exploration, and navigation. Unlike traditional large-field-of-view X-ray telescopes, the Lobster Eye Telescope can focus and image X-rays incident over a wide field of view, significantly improving its detection sensitivity, which is particularly important for the sensitive detection of transient sources in time-domain astronomy.

[0003] The Lobster Eye optical system features a spherically symmetrical structure, enabling uniform imaging of light incident from all directions. Its focal plane is spherical, unlike the plane of traditional optical systems, and its radius of curvature is half that of the Lobster Eye optical components. Existing X-ray image detector chips have planar photosensitive surfaces, which cannot be directly adapted to the focal spherical surface of the Lobster Eye optical system. Furthermore, the large field-of-view Lobster Eye telescope has a large image plane, which is insufficient for the photosensitive surface size of a single detector chip, necessitating the use of multiple detector chips in a stitched array. Current array detector stitching techniques are applied to planar arrays. To reduce defocusing caused by the curvature of the Lobster Eye optical system's focal spherical surface, the detector chips need to be stitched together into a quasi-spherical shape to meet the requirements of the optical system. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a spherical splicing method for detector chips. The spatial position of the chip is determined by calculating the center position and normal direction of the detector chip (or simply "chip") in the splicing coordinate system, thereby creating the corresponding support structure. The splicing is achieved by calculating the theoretical position and actual measured position of the marking point on the chip in the splicing coordinate system.

[0005] The objective of this invention is achieved through the following technical solution: a method for spherical splicing of detector chips, comprising the following steps:

[0006] Step 1: Based on the distance d between the center of the detector chip and the center of the focal sphere, and the azimuth angle of the chip center... The zenith angle θ at the chip center is used to determine the position of the detector chip center and the direction of the detector chip normal in the splicing coordinate system;

[0007] Step 2: Based on the position of the marker point on the detector chip in the chip coordinate system and the transformation relationship from the chip coordinate system to the stitching coordinate system, calculate the position of the marker point in the stitching coordinate system.

[0008] Step 3: Calculate the overall shape envelope based on the number, size, and spatial position of the detector chips in the splicing coordinate system, and then fabricate the corresponding support structure.

[0009] Step 4: Install the detector chip at the corresponding position on the support structure, measure the position of the marker point in the splicing coordinate system, and reduce the difference between the actual position and the theoretical position of the marker point by adjusting the position of the detector chip until the detector chip is spliced ​​in place.

[0010] Step 5: Repeat step 4 until all detector chips are in place, completing the spherical splicing of the detector chips.

[0011] A further technical solution of the present invention is as follows: the splicing coordinate system is a rectangular coordinate system with the origin O at the center of the focal sphere; the number of detector chips is N×N, and the center position of the detector chip in the i-th row and j-th column (i=1,2,3…N, j=1,2,3…N) is:

[0012]

[0013] The normal direction of the detector chip is

[0014] The chip coordinate system is a rectangular coordinate system with the origin O at the center of the detector chip, and the surface of the detector chip lies in the XOY plane of the chip coordinate system; there are n marker points around the detector chip, and the coordinates of the k-th marker point in the chip coordinate system are (x... k ,y k The transformation matrix from the chip coordinate system to the splicing coordinate system is as follows: (k = 1, 2, 3…n)

[0015]

[0016] or

[0017]

[0018] The position of the marker point in the splicing coordinate system is:

[0019]

[0020] A further technical solution of the present invention is as follows: the support structure is the mounting reference for the detector chip, and the shape of the support structure is a polyhedron made according to the overall shape envelope of the detector chip array in the splicing coordinate system. Each detector chip has a corresponding mounting surface in the support structure. After the detector chip is installed, the position can be finely adjusted in the plane where the mounting surface is located to complete the splicing of the detector chip.

[0021] As a further technical solution of the present invention, the marking point is a contact measurement marking point or a non-contact measurement marking point. The splicing accuracy of the detector chip is proportional to the number of marking points selected during measurement. The minimum number of marking points to be measured should be greater than or equal to 3.

[0022] The beneficial effects of this invention are:

[0023] (1) The detector-type spherical splicing technology used in this invention makes the spliced ​​detector chip array closer to the focal sphere of the lobster eye optical system. Compared with the traditional splicing method, it reduces the defocus caused by the curvature of the focal surface of the lobster eye optical system and improves the imaging quality.

[0024] (2) The present invention provides a method for designing the shape of the support structure. When splicing the detector, it is only necessary to install the detector chip on the corresponding mounting surface of the support structure and finely adjust the position of the detector chip within the mounting surface to complete the splicing of the detector chip. The splicing method has the advantages of being simple and efficient.

[0025] (3) This invention provides a method for calculating the position of the marker point in the splicing coordinate system. When splicing the detector, it is only necessary to compare the theoretical position and the actual position of the marker point. The detector chip can be finely adjusted to achieve the splicing in place. At the same time, the position of the detector chip in the splicing coordinate system can be deduced based on the actual position of the marker point recorded at the end. This can be further used to establish a digital twin and for parameter iteration.

[0026] (4) This invention is not only applicable to the splicing of detector chips in lobster eye optical systems, but also to the splicing of detector chips in other optical systems with spherical focal planes. Detectors spliced ​​using this method can effectively reduce the defocusing effect caused by the curvature of the focal sphere. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the spherical splicing of the 2×2 detector chip array of the present invention;

[0028] Figure 2 This is a schematic diagram of the splicing coordinate system of the 2×2 detector chip array of the present invention;

[0029] Figure 3 This is a schematic diagram of the coordinate system of the detector chip of the present invention;

[0030] Figure 4 This refers to the position of the marker point in the chip coordinate system.

[0031] Figure 5 This refers to the position of the marker point in the splicing coordinate system of the present invention;

[0032] Figure 6 This is a schematic diagram of the support structure for the 2×2 detector chip array of the present invention;

[0033] Figure 7 This is a flowchart illustrating the spherical splicing method for the detector chip of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 201 - Single detector chip; 202 - Detector chip center; 203 - Detector chip normal; 204 - Zenith angle of chip center; 205 - Azimuth angle of chip center; 301 - Detector chip pixel array; 401 - Marker point one; 402 - Marker point two; 403 - Marker point three; 404 - Marker point four. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0038] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] This invention discloses a spherical stitching method for detector chips. This method fully considers the spherical focal plane structure of the lobster-eye optical system, reduces the defocusing effect caused by existing array detector planar stitching technology, and can achieve spherical stitching that more closely approximates the shape of the focal sphere, thereby improving the imaging quality of the detector in the lobster-eye optical system. This stitching method is not only applicable to the lobster-eye optical system, but also to other optical systems with spherical focal planes.

[0040] This method first calculates the theoretical position of each detector chip in the splicing coordinate system based on the number of detector chips to be spliced, as well as parameters such as splicing distance and angle. Based on this, it calculates the theoretical position of the marker points on each detector chip in the splicing coordinate system. Then, it constructs corresponding support structures based on the theoretical positions and angles of the detector chips. After the detector chips are installed on the mounting surface corresponding to the support structure, the spatial position of the marker points is measured to determine whether the chips are properly installed. This spherical splicing method for detector chips specifically includes the following steps:

[0041] S1. First, establish a rectangular coordinate system with the origin O at the center of the focal sphere, and define it as the stitching coordinate system. The number of detector chips to be stitched is N×N. For the detector chip in the i-th row and j-th column (i = 1, 2, 3…N, j = 1, 2, 3…N), based on the distance d between the center of the detector chip and the center of the focal sphere, and the azimuth angle of the chip center… Given the zenith angle θ at the chip center, calculate the position of the detector chip center and the normal direction of the detector chip in the stitched coordinate system as follows:

[0042]

[0043] S2. Establish a rectangular coordinate system with the origin O at the center of the detector chip, and define it as the chip coordinate system. The surface of the detector chip lies within the XOY plane of the chip coordinate system. There are n marker points around the detector chip. For the k-th marker point, its position in the chip coordinate system is (x... k ,y k Given a coordinate system containing k = 1, 2, 3…n, calculate its position in the spliced ​​coordinate system as follows:

[0044]

[0045] Where X, Y, and Z represent the positions of the detector chip center in the stitching coordinate system, and R is the transformation matrix from the chip coordinate system to the stitching coordinate system.

[0046]

[0047] or

[0048]

[0049] The choice of the formula for R depends on the position of the detector chip in the stitching coordinate system.

[0050] S3. Calculate the overall shape envelope based on the number, size, and spatial position of the detector chips in the splicing coordinate system, and fabricate the corresponding support structure based on the envelope;

[0051] This support structure serves as the mounting reference for the detector chips. The structure is a polyhedron shaped according to the overall shape of the detector chip array in the splicing coordinate system, with each chip having a corresponding mounting surface within the structure. Therefore, after installation, the detector chips only need to be fine-tuned within the plane of their mounting surfaces to reduce the difference between the actual and theoretical positions of the marker points, thus completing the proper splicing of the detector chips.

[0052] S4. Install the detector chip on the corresponding mounting surface of the support structure, measure the position of the marker point in the splicing coordinate system, and reduce the difference between the actual position and the theoretical position of the marker point by adjusting the position of the detector chip until the detector chip is spliced ​​in place. The number of marker points measured should be greater than or equal to 3.

[0053] The markers can be contact or non-contact measurement markers, and the splicing accuracy of the detector chip is proportional to the number of markers selected during measurement.

[0054] S5. Repeat step four until all detector chips are in place, completing the spherical splicing of the detector chips.

[0055] The present invention will be further described below with reference to specific embodiments:

[0056] Figure 1 This is a schematic diagram of the spherical splicing of the 2×2 detector chip array of the present invention.

[0057] Figure 2 The splicing coordinate system for the detector chips in this invention is a rectangular coordinate system with the origin O at the center of the focal sphere. The distance d between the center 202 of a single detector chip 201 and the center of the focal sphere is 375mm, the zenith angle 204 of the chip center is θ = 6.8°, and the azimuth angle 205 of the chip center is... The location of detector chip center 202 is:

[0058]

[0059] The detector chip normal 203 is

[0060] Figure 3 This is the detector chip coordinate system in this invention. The chip coordinate system is a rectangular coordinate system with its origin O at the center of the chip, and the surface of the detector chip lies within the XOY plane of the chip coordinate system. For example... Figure 4 As shown, there are four marker points around the detector chip: marker point 1 (401), marker point 2 (402), marker point 3 (403), and marker point 4 (404). Their positions in the chip coordinate system are (-30.125, 31.125, 0), (30.125, 31.125, 0), (-30.125, -31.125, 0), and (30.125, -31.125, 0), respectively.

[0061] Figure 5 To determine the position of the marker point in the splicing coordinate system, the transformation matrix from the chip coordinate system to the splicing coordinate system is as follows:

[0062]

[0063] The positions of the four marker points in the splicing coordinate system are (1.272, 62.522, 372.316), (61.310, 62.310, 367.272), (1.490, 0.490, 377.528), and (61.529, 0.279, 372.484).

[0064] Figure 6 This is a schematic diagram of the support structure of the 2×2 detector chip array of the present invention. After the detector chips are installed on the corresponding mounting surfaces, the installation error of the detector chips can be determined by measuring the spatial positions of the four marker points in the splicing coordinate system and comparing them with the theoretical positions mentioned above. The splicing can then be completed by adjusting the position of the detector chips.

[0065] like Figure 5 As shown, the Z-axis in the splicing coordinate system points to the center of the detector chip array.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for spherical splicing of detector chips, characterized in that, Includes the following steps: Step 1: Determine the center position of the detector chip and the normal direction of the detector chip in the splicing coordinate system based on the distance d between the center of the detector chip and the center of the focal sphere, the azimuth angle φ of the chip center and the zenith angle θ of the chip center. The splicing coordinate system is a rectangular coordinate system with the origin O at the center of the focal sphere; the number of detector chips is N×N, and the center position of the detector chip in the i-th row and j-th column (i=1,2,3…N, j=1,2,3…N) is: ； Step 2: Based on the positions of at least three marker points on the detector chip in the chip coordinate system and the transformation relationship from the chip coordinate system to the stitching coordinate system, calculate the theoretical position of the marker points in the stitching coordinate system. The chip coordinate system is a rectangular coordinate system with the origin O at the center of the detector chip, and the surface of the detector chip lies in the XOY plane of the chip coordinate system; there are n marker points around the detector chip, and the coordinates of the k-th marker point in the chip coordinate system are (x...). k , y k The transformation matrix from the chip coordinate system to the splicing coordinate system is as follows (k=1,2,3…n): or ， The position of the marker point in the splicing coordinate system is: ； Step 3: Calculate the overall shape envelope of the detector chip array based on the number, size, and spatial position of the detector chips in the splicing coordinate system, and fabricate a polyhedral support structure whose shape corresponds to the overall shape envelope. The polyhedral support structure has mounting surfaces corresponding to each detector chip. Step 4: Install the detector chip on the corresponding mounting surface, measure the actual position of the marker point in the splicing coordinate system, and adjust the position of the detector chip in the plane where the mounting surface is located to reduce the difference between the actual position and the theoretical position of the marker point until the detector chip is spliced ​​in place. Step 5: Repeat step 4 until all detector chips are in place, completing the spherical splicing of the detector chips.

2. The method for spherical splicing of a detector chip according to claim 1, characterized in that, The marker points can be contact measurement marker points or non-contact measurement marker points, and the splicing accuracy of the detector chip is proportional to the number of marker points selected during measurement.

Images