Spherical-like splicing method for detector chips

Abstract

The invention discloses a sphere-like splicing method of a detector chip, which comprises the following steps of: determining the center position of the detector chip and the normal direction of the detector chip in a splicing coordinate system according to the distance d between the center of the detector chip and the center of a focal sphere, the azimuth angle phi of the center of the chip and the zenith angle theta of the center of the chip; calculating the position of the identification point in the splicing coordinate system according to the position of the identification point on the detector chip in the chip coordinate system and the conversion relation from the chip coordinate system to the splicing coordinate system; calculating an overall shape envelope and manufacturing a corresponding support structure; installing a detector chip at a corresponding position of the supporting structure; and the steps are repeated until all the detector chips are spliced in place, and spherical-like splicing of the detector chips is completed. The spliced detector chip array is closer to the focal spherical surface of a lobster eye optical system, and compared with a traditional splicing method, defocus caused by the curvature of the focal plane of the lobster eye optical system is reduced, and the imaging quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of lobster eye telescopes, and in particular to a spherical surface splicing method of a detector chip. Background Art

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

[0003] The lobster-eye optical system has a spherically symmetrical structure and can uniformly image light incident from all directions. Its focal plane is a spherical surface rather than a plane in a traditional optical system, and the radius of curvature of the focal spherical surface is half the radius of curvature of the lobster-eye optical device. The photosensitive surfaces of existing X-ray image detector chips are all flat surfaces, which cannot be directly adapted to the focal spherical surface of the lobster-eye optical system. At the same time, the image surface scale of the lobster-eye telescope with a large field of view is large, and the scale of the photosensitive surface of a single detector chip is difficult to meet, so multiple detector chips are required to form an array. In the prior art, the splicing technology of array detectors is all splicing technology applied to planar arrays. In order to reduce the defocus phenomenon caused by the curvature of the focal spherical surface of the lobster-eye optical system, the detector chips need to be spliced ​​into a spherical surface to meet the needs of the optical system. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a spherical splicing method for detector chips, by calculating the center position and normal direction of the detector chip (or "chip" for short) in the splicing coordinate system to determine the spatial position of the chip, thereby making a corresponding supporting structure, and by calculating the theoretical position and actual measured position of the identification point on the chip in the splicing coordinate system to achieve splicing in place.

[0005] The object of the present invention is achieved through the following technical solution: A method for splicing spherical surfaces 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 and the zenith angle θ of the chip center, determine the center position of the detector chip and the normal direction of the detector chip in the splicing coordinate system;

[0007] Step 2: Calculate the position of the identification point in the splicing coordinate system according to the position of the identification point on the detector chip in the chip coordinate system and the transformation relationship from the chip coordinate system to the splicing coordinate system;

[0008] Step 3: Calculate the overall shape envelope according to the number, size and spatial position of the detector chips in the splicing coordinate system, and then make the corresponding support structure;

[0009] Step 4: Install the detector chip at the corresponding position of the support structure, measure the position of the identification point in the splicing coordinate system, and reduce the gap between the actual position and the theoretical position of the identification 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 spliced ​​in place, completing the spherical splicing of the detector chips.

[0011] As a further technical solution of the present invention, 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 is located in the XOY plane of the chip coordinate system; there are n identification points around the detector chip, and the coordinates of the kth identification point in the chip coordinate system are (x k ,y k ,0)(k=1,2,3…n), the transformation matrix from the chip coordinate system to the splicing coordinate system is:

[0015]

[0016] or

[0017]

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

[0019]

[0020] As a further technical solution of the present invention, the support structure is an installation 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, and each detector chip has a corresponding installation surface in the support structure; after the detector chip is installed, it is only necessary to fine-tune the position within the plane where the installation surface is located to complete the splicing of the detector chip into place.

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

[0022] The beneficial effects of the present invention are:

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

[0024] (2) The present invention provides a method for designing the appearance of a support structure. When splicing detectors, the detector chips only need to be installed on the corresponding mounting surface of the support structure. The detector chips can be spliced ​​into place by fine-tuning the positions of the detector chips within the mounting surface. The splicing method has the advantages of being simple and efficient.

[0025] (3) The present invention provides a method for calculating the position of the identification point in the splicing coordinate system. When splicing the detectors, it is only necessary to compare the theoretical position of the identification point with the actual position, and the detector chip can be fine-tuned to achieve the splicing in place. At the same time, the position of the detector chip in the splicing coordinate system can be inferred based on the actual position of the identification point finally recorded, which can be further used to establish a digital twin and parameter iteration.

[0026] (4) The present invention is not only applicable to the detector chip splicing of the lobster eye optical system, but also applicable to the detector chip splicing of other optical systems whose focal plane is a spherical surface. The detector spliced ​​using this method can effectively reduce the defocus effect caused by the curvature of the focal spherical surface. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0030] Figure 4 is the position of the identification point of the present invention in the chip coordinate system;

[0031] Figure 5 is the position of the identification point of the present invention in the splicing coordinate system;

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

[0033] Figure 7 It is a schematic diagram of the flow of the spherical surface splicing method of the detector chip of the present invention.

[0034] Description of reference numerals:

[0035] 201-single detector chip; 202-center of the detector chip; 203-normal of the detector chip; 204-zenith angle of the chip center; 205-azimuth angle of the chip center; 301-pixel array of the detector chip; 401-marking point one; 402-marking point two; 403-marking point three; 404-marking point four. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is 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 due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0038] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0039] The present invention discloses a spherical surface splicing method for detector chips, which fully considers the spherical focal plane structure of the lobster-eye optical system, reduces the defocusing effect caused by the existing array detector plane splicing technology, can achieve spherical surface splicing that is closer to the focal spherical surface shape, and improves the imaging quality of the detector in the lobster-eye optical system. The splicing method is not only applicable to the lobster-eye optical system, but also to other optical systems with spherical focal planes.

[0040] The 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 ​​and the splicing distance, angle and other parameters, and then calculates the theoretical position of the identification point on each detector chip in the splicing coordinate system based on this. Then, the corresponding support structure is made according to the theoretical position and angle of the detector chip. After the detector chip is installed on the mounting surface corresponding to the support structure, the spatial position of the identification point is measured to determine whether the chip is installed in place. The detector chip spherical splicing method 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 splicing coordinate system. The number of detector chips to be spliced ​​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), according to the distance d between the center of the detector chip and the center of the focal sphere, the azimuth angle of the chip center and the zenith angle θ of the chip center, the center position of the detector chip and the normal direction of the detector chip in the splicing coordinate system are calculated 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 is located in the XOY plane of the chip coordinate system. There are n identification points around the detector chip. For the kth identification point, its position in the chip coordinate system is (x k ,y k ,0)(k=1,2,3…n), calculate its position in the splicing coordinate system as:

[0044]

[0045] Among them, X, Y, Z are the positions of the center of the detector chip in the splicing coordinate system, and R is the transformation matrix from the chip coordinate system to the splicing coordinate system:

[0046]

[0047] or

[0048]

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

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

[0051] The support structure is the installation reference of the detector chip. 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. Therefore, after the detector chip is installed, it only needs to fine-tune the position within the plane where the mounting surface is located to reduce the gap between the actual position of the identification point and the theoretical position, and complete the splicing of the detector chip in place.

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

[0053] The identification points are contact measurement identification points or non-contact measurement identification points, and the stitching accuracy of the detector chip is proportional to the number of identification points selected during measurement.

[0054] S5. Repeat step 4 until all detector chips are spliced ​​in place, completing the spherical splicing of the detector chips.

[0055] The present invention will be further described below in conjunction with specific embodiments:

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

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

[0058]

[0059] The detector chip normal 203 is

[0060] Figure 3 The detector chip coordinate system in the present invention is a rectangular coordinate system with the origin O at the center of the chip, and the surface of the detector chip is located in the XOY plane of the chip coordinate system. Figure 4 As shown, there are four identification points around the detector chip, namely identification point one 401, identification point two 402, identification point three 403, and identification point four 404, and their positions in the chip coordinate system are respectively (-30.125, 31.125, 0), (30.125, 31.125, 0), (-30.125, -31.125, 0), and (30.125, -31.125, 0).

[0061] Figure 5 is the position of the identification point of the present invention in the splicing coordinate system, and the conversion matrix from the chip coordinate system to the splicing coordinate system is:

[0062]

[0063] The positions of the four identification points in the stitching 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 installation surface, the installation error of the detector chips can be determined by measuring the spatial positions of the four identification points in the splicing coordinate system and comparing them with the above-mentioned theoretical positions. The detector chips can then be adjusted in position to finally achieve splicing in place.

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

[0066] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for spherical surface splicing of a detector chip, characterized in that The steps include: 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 and the zenith angle θ of the chip center, determine the center position of the detector chip and the normal direction of the detector chip in the splicing coordinate system; Step 2: Calculate the position of the identification point in the splicing coordinate system according to the position of the identification point on the detector chip in the chip coordinate system and the transformation relationship from the chip coordinate system to the splicing coordinate system; Step 3: Calculate the overall shape envelope according to the number, size and spatial position of the detector chips in the splicing coordinate system, and then make the corresponding support structure; Step 4: Install the detector chip at the corresponding position of the support structure, measure the position of the identification point in the splicing coordinate system, and reduce the gap between the actual position and the theoretical position of the identification point by adjusting the position of the detector chip until the detector chip is spliced ​​in place; Step 5: Repeat step 4 until all detector chips are spliced ​​in place, completing the spherical splicing of the detector chips.

2. The method for spherical surface splicing of a detector chip according to claim 1, characterized in that: 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: The normal direction of the detector chip is 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 is located in the XOY plane of the chip coordinate system; there are n identification points around the detector chip, and the coordinates of the kth identification point in the chip coordinate system are (x k ,y k ,0)(k=1,2,3…n), the transformation matrix from the chip coordinate system to the splicing coordinate system is: or The position of the identification point in the splicing coordinate system is:

3. The method for spherical surface splicing of a detector chip according to claim 2, characterized in that: The support structure is the installation reference of the detector chip. 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 installation surface in the support structure. After the detector chip is installed, it can be spliced ​​into place by simply fine-tuning the position within the plane where the installation surface is located.

4. The method for spherical surface splicing of a detector chip according to claim 3, characterized in that: The identification points are contact measurement identification points or non-contact measurement identification points. The stitching accuracy of the detector chip is proportional to the number of identification points selected during measurement. The minimum number of identification points to be measured should be greater than or equal to 3.

Images