Micro-channel plate surface shape automatic detection system and detection method

Abstract

The invention relates to a micro-channel plate surface shape automatic detection system and detection method, and the detection system is characterized in that a lead screw is arranged above a bearing platform, a quartz boat is nested on the lead screw, and the lead screw is connected with a motor; the quartz boat is provided with a clamping groove position for clamping a to-be-measured micro-channel plate, the rotary strip lamp is arranged on one side of the quartz boat and is used for irradiating the to-be-measured micro-channel plate to form projection, and the length of the rotary strip lamp is greater than the maximum size of the appearance of the to-be-measured micro-channel plate; the image acquisition and processing system is arranged on the other side of the quartz boat and is used for acquiring a projection image of the rotary strip-shaped lamp on the to-be-detected micro-channel plate and transmitting the image to the image processing system in real time; the image processing system realizes detection of deformation at different positions through color space transformation, binary analysis, contour analysis, line segment detection, gradient fitting-based accurate edge detection and projection deformation quantity deviation calculation. According to the invention, the detection efficiency and the detection precision are improved, and the micro deformation of the edges of various special-shaped micro-channel plates can be discriminated.

Description

Technical Field

[0001] The invention relates to the technical field of microchannel plates, and in particular to an automatic detection system and method for the surface shape of a microchannel plate. Background Art

[0002] Microchannel plate (MCP) is a two-dimensional vacuum electron multiplier element with a honeycomb array structure consisting of thousands of channels. It is a key material in devices such as low-light image intensifiers, ultraviolet detectors, and photomultiplier tubes. It has the characteristics of high gain, high signal-to-noise ratio, and high resolution.

[0003] In recent years, with the development of optoelectronic imaging detection technology, optoelectronic devices such as low-light image intensifiers have increasingly higher requirements for resolution, a key performance, and the core multiplication material, MCP, directly determines the resolution performance. The resolution of MCP is inversely proportional to the channel aperture, and each channel is equivalent to a pixel. To improve the resolution of MCP, the most direct way is to further reduce its channel aperture. However, due to the limitation of the optimal aspect ratio, the reduction of the channel aperture will force the thickness of MCP to decrease accordingly; and in its preparation process, it will undergo a series of thermal processes and structural strength changes such as acid-base corrosion and high-temperature hydrogen reduction, which will inevitably cause MCP to be easily deformed and cracked during production and use, ultimately affecting the assembly of the image intensifier, reducing image resolution and coupling efficiency, so deformation detection of MCP is particularly important.

[0004] Usually, MCP is prepared in batches during processes such as acid-base corrosion and hydrogen reduction. In the traditional board deformation detection method, the MCP needs to be manually clamped one by one on the fixture and placed horizontally, and then judged individually with the help of lamp projection, which is inefficient and prone to damage caused by operational errors during the clamping process; in addition, the judgment still uses visual inspection, and it is difficult to detect slight deformation, which is greatly affected by human factors and has the risk of missed detection; Chinese patents CN109579748B and CN114608467A both use a single-chip cross-line projection detection method to infer the flatness of MCP by judging the cross-line angle, but for some special-shaped MCPs such as annular, rectangular and fan-shaped, their slight deformation may exist at the edge of the board, and the cross-line angle located only in the center of the board cannot achieve comprehensive detection; using the straight line or vector approximate fitting method, when the cross projection bending amount is large, the judgment error of the fitted angle and flatness is large. Summary of the invention

[0005] The main purpose of the present invention is to provide a microchannel plate surface shape automatic detection system which improves detection accuracy and detection efficiency.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A microchannel plate surface automatic detection system includes a carrying platform, a screw rod, a quartz boat, a rotating strip light, and an image acquisition and processing system;

[0008] A screw rod is provided above the carrying platform, a quartz boat is nested on the screw rod, and the screw rod is connected to a motor;

[0009] The quartz boat is provided with at least one clamping slot, and the clamping slot is used to clamp the microchannel plate to be tested;

[0010] The rotating strip light is arranged on one side of the quartz boat, and is used to illuminate the microchannel plate to be tested to form a projection, and the length of the rotating strip light is greater than the maximum size of the microchannel plate to be tested;

[0011] The image acquisition and processing system is arranged on the other side of the quartz boat, and comprises an image acquisition device and an image processing system, wherein the image acquisition device is used to acquire the projection image of the rotating strip light on the microchannel plate to be tested, and transmit the image to the image processing system in real time;

[0012] The image processing system realizes the detection of deformation at different positions through color space transformation, binary analysis, contour analysis, line segment detection, precise edge detection based on gradient fitting, and deviation calculation of the projection deformation of the rotating strip light.

[0013] The bottom of the quartz boat is provided with at least two threaded sleeves, and there are two screw rods, each of which passes through at least one threaded sleeve and is fixedly connected to the quartz boat.

[0014] The quartz boat is provided with more than two clamping slots, which are arranged at a certain distance. The microchannel plate to be tested on each clamping slot is placed vertically relative to the supporting platform, and each microchannel plate to be tested can achieve axial movement with the quartz boat.

[0015] Furthermore, the spacing between two adjacent microchannel plates to be tested is 10-20 mm.

[0016] The geometric center of the projection of the rotating strip light falls on the geometric center of the microchannel plate to be tested, and the projection length is greater than the maximum dimension of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 2 to 6 mm;

[0017] The initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. When it starts working, the lamp tube can rotate along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30 degrees every 0.2 seconds. When a microchannel plate detection is completed, the lamp tube rotates 180 degrees.

[0018] The lamp tube of the rotating strip light is a white light LED lamp tube. The length of the rotating strip light is 100-200 mm and the width is 10-30 mm. The geometric center of the rotating strip light is 100-200 mm higher than the geometric center of the first microchannel plate to be tested. The distance between the geometric centers of the two is 150-200 mm. The angle θ between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45-60°.

[0019] The image acquisition device is a high-definition industrial camera. The geometric center of the image acquisition device is 100-200 mm higher than the geometric center of the first microchannel plate to be tested. The distance between the geometric center of the image acquisition device and the geometric center of the first microchannel plate to be tested is 150-200 mm. The angle β between the line connecting the geometric center of the image acquisition device and the geometric center of the first microchannel plate to be tested and the axial direction of the quartz boat is 45-60°.

[0020] The present invention also provides a method for detecting the surface shape of a microchannel plate using the microchannel plate surface shape automatic detection system, comprising the following steps:

[0021] (1) Install the microchannel plate to be tested: Use a multi-slot quartz boat to hold 1 to 100 microchannel plates to be tested. Each microchannel plate to be tested is placed vertically relative to the quartz boat. The threaded sleeve at the bottom of the quartz boat is nested with the screw on the supporting platform, and then tightened by screwing to ensure that the relative position of the quartz boat and the screw is fixed without sliding;

[0022] (2) Installing a rotating strip light: placing the rotating strip light on one side of the quartz boat, wherein the geometric center of the rotating strip light is 100 to 200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the two geometric centers is 150 to 200 mm, and the angle θ between the line connecting the two geometric centers and the axial direction of the quartz boat is 45 to 60°;

[0023] (3) Setting the working parameters of the rotating strip light: adjusting the geometric center of the projection of the rotating strip light to fall on the geometric center of the first microchannel plate to be tested, and the projection length is greater than the maximum size of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 2 to 6 mm; the initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. After starting to work, the lamp tube is rotated clockwise along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30 degrees every 0.2 seconds, and completing the detection of a microchannel plate to be tested after rotating 180 degrees;

[0024] (4) Installing an image acquisition device: placing the image acquisition device on the side of the quartz boat, the geometric center of the image acquisition device is 100-200 mm higher than the geometric center of the first microchannel plate to be tested, and the distance is 150-200 mm. The angle β between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45-60°, so that the projection of the rotating strip light on the microchannel plate to be tested can be completely reflected to the camera. The image acquisition device takes a projection at an interval of 0.2s and transmits the image to the image processing system in real time. After the rotating strip light completes a 180° rotation, the single microchannel plate projection detection image acquisition is completed;

[0025] (5) The processing process of the image processing system:

[0026] ① Using OpenCV experimental platform software, the edge shape of the rotating strip light projection in each image is determined through color space transformation, binary analysis, projection contour analysis, line segment detection, and precise edge detection based on gradient fitting;

[0027] ② The area to be inspected of the microchannel plate is divided into a channel area and an edge area, and the channel area is further divided into area I, area II and area III;

[0028] ③ The edge shape of the projection of each image is compared with the edge shape of the preset projection without deformation, and the deformation deviation of the projection corresponding to different rotation angles of the rotating strip light is calculated, and then the average percentage of the deformation deviation of the single MCP is calculated;

[0029] According to the partition limit, the edge shape of each partition projection is compared with the edge shape of the preset projection of each zone without deformation, and the deformation deviation of each partition projection corresponding to different rotation angles of the rotating strip light is calculated, and then the average percentage of the deformation deviation of each partition is calculated;

[0030] ④ Determine the flatness of the single-piece microchannel plate to be tested according to the mean percentage deviation of the single-piece MCP deformation variable; judge the area prone to deformation according to the comparison result of the mean percentage deviation of the deformation variable of each partition and the mean percentage deviation of the single-piece MCP deformation variable, and judge the cause of MCP deformation according to the area prone to deformation;

[0031] (6) Batch testing: After a piece of microchannel plate to be tested is tested, the motor drives the lead screw to move the quartz boat along its axial direction, and moves a new piece of microchannel plate to be tested to the initial testing position, and repeats steps (3) to (5).

[0032] The moving speed of the screw rod is 20 mm / s to 40 mm / s, and the single moving distance is 10 to 20 mm.

[0033] By means of the above technical solution, the present invention has at least the following advantages:

[0034] 1. The detection system and detection method proposed in the present invention can realize non-destructive, batch, and automated rapid detection of MCP surface shape. No human intervention is required during the large-scale detection of a single quartz boat, which improves the detection efficiency while avoiding damage to the MCP surface caused by manual operation and errors.

[0035] 2. The 180° projection scanning method of the rotating strip light can realize full coverage detection of the MCP surface, effectively avoiding the problem of missed detection of deformation in the edge area of ​​special-shaped MCP.

[0036] 3. The precise fitting of the projection contour edge and the calculation method of deformation deviation are adopted. There is no need to perform linear or vector approximation on the deformation projection, which can ensure that what is measured is what is obtained. The measurement accuracy is high and the apparent quality of the product can be guaranteed to the greatest extent.

[0037] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of an MCP face shape automatic detection system provided by an embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of circular microchannel plate surface shape detection provided by an embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of rectangular microchannel plate surface shape detection provided by an embodiment of the present invention;

[0041] Figure 4 is a schematic diagram of detecting the surface shape of a sector-shaped microchannel plate provided by an embodiment of the present invention;

[0042] Figure 5 is a schematic projection diagram of the deformation of the strip light on the microchannel plate provided by an embodiment of the present invention;

[0043] Figure 6 It is a schematic projection diagram of the strip light provided by an embodiment of the present invention without deformation on the microchannel plate.

[0044] Explanation of reference numerals: 1-projection; 2-rotating strip light; 3-MCP to be tested; 4-quartz boat; 5-carrying platform; 6-image acquisition and processing system; 7-screw; 8-gear box; 9-motor. DETAILED DESCRIPTION

[0045] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0046] like Figure 1 As shown, a microchannel plate surface shape automatic detection system includes a carrying platform 5, a screw rod 7, a quartz boat 4, a rotating strip light 2, and an image acquisition and processing system 6;

[0047] A screw rod 7 is provided above the carrying platform 5, a quartz boat 4 is nested on the screw rod 7, and the screw rod 7 is connected to a motor 9 through a gear box 8;

[0048] At least one clamping slot is provided on the quartz boat 4, and the clamping slot is used to clamp the microchannel plate 3 to be tested;

[0049] The rotating strip light 2 is arranged on one side of the quartz boat 4, and is used to illuminate the microchannel plate to be tested to form a projection 1. The length of the rotating strip light 2 is greater than the maximum size of the microchannel plate 3 to be tested.

[0050] The image acquisition and processing system 6 is arranged on the other side of the quartz boat 4. The image acquisition device is used to acquire the projection image 1 of the rotating strip light on the microchannel plate to be tested, and transmit the image to the image processing system in real time. The arrow direction shown by AB is the axial direction of the quartz boat.

[0051] The image processing system realizes the detection of deformation at different positions through color space transformation, binary analysis, contour analysis, line segment detection, precise edge detection based on gradient fitting, and deviation calculation of the projection deformation of the rotating strip light.

[0052] The present invention adopts an electric control device to drive the movement of the microchannel plate to be inspected, and combines it with an image recognition method in a single scene to realize automatic identification of the surface shape of the microchannel plate, solve the problems of low efficiency of MCP surface shape detection, detection damage, missed detection of small deformation in the edge area of ​​the special-shaped plate surface and large identification error, improve the detection accuracy and detection efficiency, and ensure the apparent quality of the product and the pipe manufacturing performance.

[0053] Preferably, at least two threaded sleeves are provided at the bottom of the quartz boat 4, preferably two threaded sleeves, and each screw rod 7 passes through a threaded sleeve and is fixedly connected to the quartz boat 4. The threaded sleeve plays a supporting role on the one hand, and is nested with the screw rod on the other hand to drive the quartz boat to move axially.

[0054] Preferably, more than two clamping slots are provided inside the quartz boat 4 , and the clamping slots are arranged at a certain distance. The microchannel plate 3 to be tested on each clamping slot is placed vertically relative to the supporting platform 5 , and each microchannel plate 3 to be tested can achieve axial movement with the quartz boat 4 .

[0055] Furthermore, the spacing between two adjacent microchannel plates 3 to be tested is 10-20 mm.

[0056] Setting the distance between two adjacent microchannel plates 3 to be tested to 10-20 mm has the following advantages:

[0057] (1) Ensure that during the manual clamping and disassembly of the microchannel plate, the two adjacent plates are separated by about 10-20 mm and will not collide and be damaged;

[0058] (2) During the high-temperature hydrogen reduction process, the spacing between two adjacent microchannel plates to be tested has been determined to be 10-20 mm so as to allow for full reduction without affecting the electrical properties of the microchannel plates;

[0059] (3) According to the design requirements of the present invention and in combination with the relative positions of the rotating strip light, the quartz boat, and the image acquisition and processing system, the interval between two adjacent microchannel plates to be tested needs to be more than 10 mm, and as the quartz boat moves, the light projection on the next microchannel plate to be tested can be collected one by one. In addition, in order to maximize the number of samples to be tested on the quartz boat, the interval between two adjacent microchannel plates to be tested should not be too large, and the interval between each MCP is constant. The stepping speed and distance of the quartz boat are controlled by a motor, so that each MCP to be tested moves to the position to be tested one by one and stays for inspection.

[0060] Preferably, the geometric center of the projection 1 of the rotating strip light 2 falls on the geometric center of the microchannel plate 3 to be tested, and the length of the projection 1 is greater than the maximum dimension of the microchannel plate 3 to be tested. When the microchannel plate 3 to be tested is not deformed, the width of the projection 1 is 2 to 6 mm.

[0061] The initial direction of the rotating strip light 2 is that the lamp tube is perpendicular to the horizontal plane. When it starts working, the lamp tube can rotate along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30° every 0.2s. When a microchannel plate detection is completed, the lamp tube rotates 180°.

[0062] Preferably, the lamp tube of the rotating strip light 2 is a white light LED lamp tube; the length of the rotating strip light 2 is 100-200 mm, the width is 10-30 mm, the geometric center of the rotating strip light 2 is 100-200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the geometric center of the rotating strip light 2 and the geometric center of the microchannel plate to be tested is 150-200 mm, and the angle θ between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45-60°.

[0063] The length of the rotating strip light is greater than the maximum dimension of the MCP to be tested (about 100mm), which means that within a certain lighting distance, the geometric center of the rectangular projection of the strip light coincides with the geometric center of the MCP, and the projection length of the strip light is greater than the maximum dimension of the MCP to be tested. The rotating strip light rotates clockwise, that is, the strip light is projected on the vertically placed MCP surface and rotates clockwise.

[0064] After the rotating strip light of the present invention rotates 180° clockwise within a certain rotation speed, the sample can be fully scanned and tested without any missed points, which plays a key role in controlling the quality of the sample.

[0065] Preferably, the image acquisition device is a high-definition industrial camera, the geometric center of the image acquisition device is 100 to 200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the geometric center of the image acquisition device and the geometric center of the first microchannel plate to be tested is 150 to 200 mm, and the angle β between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45 to 60°.

[0066] The image acquisition device and the rotating strip light of the present invention are at the same height. After the geometric centers of the two are connected with the geometric center of the microchannel plate to be measured, the angles between the connecting lines and the axial direction of the quartz boat are the same, that is, θ and β are the same.

[0067] The image processing system of the present invention performs training and feature extraction of multiple projection images in advance. The projection of the strip light on the MCP to be tested is completely reflected into the camera. The shooting frequency of the camera is kept at the same frequency as the rotation of the strip light, and it takes a picture once every 0.2s and transmits the image to the image processing system in real time. During real-time detection, the camera can directly import the collected projection image into the OpenCV (Open Source Computer Vision Library) experimental platform software, and finally realize the all-round deformation detection of the sample through color space transformation, binary analysis, contour analysis, line segment detection, precise edge detection based on gradient fitting, and strip light projection deformation deviation calculation.

[0068] The design idea of ​​the MCP surface shape detection proposed in the present invention is: the quartz boat is mounted on an electric slide rail and can move in the axial direction. Multiple MCPs to be tested are placed vertically on the quartz boat. The rotating strip light is projected onto the board surface of the MCP after the rotating lamp tube, and then reflected to the image acquisition and processing system for image processing and analysis and measurement. By judging the rectangular size and deformation amount of the projection of the rotating strip light strip on the board surface, the flatness of the board surface and the morphology of the edge area can be fitted. When the inspection of a piece of MCP is completed, the motor controls the stepping speed and distance of the quartz boat, so that each piece of MCP to be tested moves to the position to be tested one by one and stays for inspection.

[0069] The method for detecting the surface shape of a microchannel plate using an automatic detection system for the surface shape of a microchannel plate provided by the present invention comprises the following steps:

[0070] (1) Install the microchannel plate to be tested: Use a multi-slot quartz boat to hold 1 to 100 microchannel plates to be tested. Each microchannel plate to be tested is placed vertically relative to the quartz boat. The threaded sleeve at the bottom of the quartz boat is nested with the screw on the supporting platform, and then tightened by screwing to ensure that the relative position of the quartz boat and the screw is fixed without sliding;

[0071] (2) Installing a rotating strip light: placing the rotating strip light on one side of the quartz boat, wherein the geometric center of the rotating strip light is 100 to 200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the two geometric centers is 150 to 200 mm, and the angle θ between the line connecting the two geometric centers and the axial direction of the quartz boat is 45 to 60°;

[0072] (3) Setting the working parameters of the rotating strip light: adjusting the geometric center of the projection of the rotating strip light to fall on the geometric center of the first microchannel plate to be tested, and the projection length is greater than the maximum size of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 2 to 6 mm; the initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. After starting to work, the lamp tube is rotated clockwise along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30 degrees every 0.2 seconds, and completing the detection of a microchannel plate to be tested after rotating 180 degrees;

[0073] (4) Installing an image acquisition device: placing the image acquisition device on the side of the quartz boat, the geometric center of the image acquisition device is 100-200 mm higher than the geometric center of the first microchannel plate to be tested, and the distance is 150-200 mm. The angle β between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45-60°, so that the projection of the rotating strip light on the microchannel plate to be tested can be completely reflected to the camera. The image acquisition device takes a projection at an interval of 0.2s and transmits the image to the image processing system in real time. After the rotating strip light completes a 180° rotation, the single microchannel plate projection detection image acquisition is completed;

[0074] (5) The processing process of the image processing system:

[0075] ① Using OpenCV experimental platform software, the edge shape of the rotating strip light projection in each image is determined through color space transformation, binary analysis, projection contour analysis, line segment detection, and precise edge detection based on gradient fitting;

[0076] ② The area to be inspected of the microchannel plate is divided into a channel area and an edge area, and the channel area is further divided into area I, area II and area III;

[0077] ③ Compare the edge shape of each image projection with the edge shape of the preset projection without deformation, calculate the deformation deviation of the projection corresponding to different rotation angles of the rotating strip light, and then calculate the mean percentage of the deformation deviation of the single-chip MCP according to the formula;

[0078] The OpenCV algorithm is used to detect the edge shape of the projection, count the number of pixels in the projection, and finally calculate the area of ​​the projection image. Every time the rotating strip light rotates to an angle, the deformation deviation Sn is calculated according to the area of ​​the projection image, that is, the deformation deviation Sn is the absolute value of the detection projection area minus the normal projection area, n is the sequence number of the captured image, the sequence number of the initial captured image is set to 1, 0.2s later, the strip light rotates 5 to 30°, the sequence number of the captured image is 2, and so on, the sequence number of the captured image is n. After the strip light rotates 180°, the entire MCP detection is completed, and the average percentage of the deformation deviation of a single MCP = (S1+S2++…Sn) / (n*normal projection area)*100%.

[0079] Similarly, according to the partition limit, the edge shape of each partition projection and the edge shape of the preset projection of each zone without deformation can be compared to calculate the deformation deviation of each partition projection corresponding to different rotation angles of the rotating strip light, and then the average deformation deviation percentage of each partition can be calculated according to the formula: average deformation deviation percentage = (S1 + S2++...Sn) / (n*normal projection area) * 100%;

[0080] The detection projection area refers to the projection area of ​​each image obtained by calculation and detection, and the normal projection area is the preset projection area without deformation under the same specification of MCP, the same test conditions and parameters.

[0081] ④ Determine the flatness of the single-chip microchannel plate to be tested according to the mean value of the single-chip MCP deformation deviation percentage;

[0082] According to the comparison results of the average percentage deviation of the deformation variables of each partition and the average percentage deviation of the deformation variables of a single MCP, the area prone to deformation is judged, and the cause of MCP deformation is judged according to the area prone to deformation;

[0083] Compare the mean percentage deviation of the deformation variables of each partition with the mean percentage deviation of the deformation variables of the single MCP, and obtain the partition with the largest mean percentage deviation of the deformation variables, which is the area prone to deformation, and then determine the cause of MCP deformation;

[0084] When the MCP to be tested is not deformed, the projection of the rectangular strip light is straight and the width is always constant; when the MCP is deformed at any position, the projection of the rectangular strip light is distorted and its width changes, and the degree of deformation and the flatness of the sample can be deduced; through the detection of similar samples and the data accumulation and analysis of each partition, the area prone to deformation, that is, the strain point, can be further extracted. When the central zone I is the area prone to deformation, it can be judged that it is mainly caused by the reduction process; when the II and III zones are the areas prone to deformation, it is mainly the material matching problem of the channel area and the hemming area; when the hemming area is the area prone to deformation, it is mainly the problem of reduction clamping or the size of the quartz boat. Therefore, the cause of MCP deformation can be judged according to the area prone to deformation.

[0085] (6) Batch testing: After a piece of microchannel plate to be tested is tested, the motor drives the screw to move along the axial direction (AB direction) of the quartz boat at a speed of 20 mm / s to 40 mm / s, and the quartz boat is also moved along its axial direction. The single movement distance is 10 to 20 mm, and a new piece of microchannel plate to be tested is moved to the initial position to be tested, and steps (3) to (5) are repeated.

[0086] Table 1 Detection parameters of various embodiments

[0087]

[0088]

[0089] Table 2 Flatness test results comparison table

[0090] Mean value of the percentage deviation of the single-piece MCP deformation Flatness / μm 0 0 0～20％ 0～20 20％～40％ 20～40 40％～60％ 40～60 60％～80％ 60～80 80％～100％ 80～100

[0091] During the training of the image processing system, the MCP with a known mean percentage deviation of the deformation variable is placed on a white light interferometer for a flatness verification test, and the flatness value corresponding to the mean percentage deviation of the deformation variable of a single MCP can be determined.

[0092] The detection method of the present invention is further illustrated by specific implementation below.

[0093] Example 1

[0094] A method for automatically detecting the surface shape of a circular microchannel plate comprises the following steps:

[0095] (1) Install the MCP to be tested: usually use a multi-slot quartz boat to hold 1 to 100 MCPs for batch acid-base corrosion and high-temperature hydrogen reduction. The MCP to be tested is a Φ25mm circular plate. Each MCP to be tested is placed vertically relative to the quartz boat axis, and the interval between two adjacent MCPs is 20mm. After the corrosion or reduction is completed, the threaded sleeve at the bottom of the quartz boat is nested with the screw on the supporting platform, and then tightened by threading to ensure that the relative position of the quartz boat and the screw is fixed without sliding;

[0096] (2) Install the rotating strip light: The length of the rotating strip light is 100 mm and the width is 10 mm. The rotating strip light is placed on one side of the quartz boat, with its geometric center 200 mm higher than the geometric center of the first microchannel plate to be tested, and the distance between the two geometric centers is 200 mm. The angle θ between the line connecting the two geometric centers and the axial direction of the quartz boat is 60°;

[0097] (3) Setting the working parameters of the rotating strip light: adjusting the geometric center of the light projection of the rotating strip light to fall on the geometric center of the first microchannel plate to be tested, and the projection length is greater than the maximum size of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 3 mm; the initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. After starting to work, the lamp tube is rotated clockwise along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 30° every 0.2s. After rotating 180°, the detection of a microchannel plate to be tested is completed;

[0098] (4) Install the image acquisition device: Place the image acquisition device on the other side of the quartz boat, with its geometric center 200 mm higher than the geometric center of the first microchannel plate to be tested, and the distance is 200 mm. The angle β between the line connecting the geometric centers of the two and the axis of the quartz boat is 60°, so that the projection of the rotating strip light on the microchannel plate to be tested can be completely reflected to the camera. The image acquisition device takes a projection at an interval of 0.2 s and transmits the image to the image processing system in real time. After the rotating strip light completes a 180° rotation, the single microchannel plate projection detection image acquisition is completed;

[0099] (5) The processing process of the image processing system:

[0100] ① Using OpenCV experimental platform software, the edge shape of the rotating strip light projection in each image is determined through color space transformation, binary analysis, projection contour analysis, line segment detection, and precise edge detection based on gradient fitting;

[0101] ② According to the inspection requirements and appearance parameters of the microchannel plate, the area to be inspected is divided into zones to further detect and analyze the deformation of the channel area and the edge area at key locations;

[0102] ③ Compare the edge shape of each image projection with the edge shape of the preset projection without deformation, and then calculate the deformation deviation of the projection corresponding to different rotation angles of the rotating strip light according to the formula;

[0103] See also Figure 5 and Figure 6 , which are the projection shapes of the rotating strip light on the microchannel plate. Figure 5 For the deformed strip light projection, Figure 6 For the normal undeformed strip light projection, the OpenCV algorithm is used to detect the edge shape of the projection, and the number of pixels in the projection is counted, and the area of ​​the projection image can be finally calculated. For each angle to which the rotating strip light rotates, the deformation variable deviation Sn is calculated according to the area of ​​the projection image, that is, the deformation variable deviation Sn is the absolute value of the detection projection area minus the normal projection area, and n is the sequence number of the captured image. The sequence number of the initial captured image is set to 1. After 0.2s, the strip light rotates 30°, and the sequence number of the captured image is 2. And so on, the sequence number of the captured image is 7. After the strip light rotates 180°, the entire MCP detection is completed, and a total of 7 images need to be taken. The average percentage of the single-piece deformation variable deviation = (S1+S2+S3+S4+S5+S6+S7) / (7*normal projection area)*100%.

[0104] Similarly, for the deformation of each partition, it is only necessary to calculate the detected projection area and the normal projection area within the partition, and then the mean percentage deviation of the deformation variable can be obtained.

[0105] ④ Referring to Table 2, determine the flatness of the single microchannel plate to be tested according to the mean percentage deviation of the single MCP deformation variable; determine whether the product is qualified based on the flatness result. According to the microchannel plate standard, the flatness of microchannel plates for night vision should be ≤15μm. The flatness of microchannel plates for some other application scenarios or other customers can be relaxed to a maximum of 80μm. According to the conventional MCP plate flatness reference value, during real-time batch detection, it is only necessary to call the trained single-piece deformation variable deviation percentage mean and the corresponding data package for flatness (the corresponding values ​​in Table 2) for comparison and analysis to determine the flatness and thus determine whether the product is qualified.

[0106] The normal undeformed projected area of ​​the Φ25 mm circular MCP in this embodiment is 72 mm 2 The specific test results of the first MCP to be tested are: the projection area of ​​the strip light after each rotation of 30° is 80mm 2 、81mm 2 , 75mm 2 、72mm 2 、70mm 2 、85mm 2 , 80mm 2, that is, S1 = 8mm 2 、S2=9mm 2 、S3=3mm 2 、S4=0mm 2 、S5=2mm 2 、S6=13mm 2 、S7=8mm 2 According to the formula, the average percentage deviation of single-piece deformation variable is 8.9% (S1+S2+S3+S4+S5+S6+S7) / (7*72)*100%, which corresponds to a flatness of 8.9 μm, meeting the flatness requirements of the microchannel plate for night vision.

[0107] For the deformation of each partition, the normal undeformed projection area of ​​channel I is 27mm 2 The specific test results are: the projection area of ​​the strip light after each rotation of 30° is 29mm 2 、29mm 2 、28mm 2 、27mm 2 、23mm 2 、31mm 2 , 35mm 2 , that is, SⅠ1=2mm 2 、SⅠ2=2mm 2 、SⅠ3=1mm 2 、SⅠ4=0mm 2 、SⅠ5=4mm 2 、SⅠ6=4mm 2 、SⅠ7=8mm 2 According to the formula, the average percentage deviation of deformation variable in channel I area = (SⅠ1+SⅠ2+SⅠ3+SⅠ4+SⅠ5+SⅠ6+SⅠ7) / (7*27)*100%, the average percentage deviation of deformation variable is 11%; for the detection of channel II area, III area and edge area, the normal undeformed projection area is 20mm in II area. 2 、Zone III 20mm 2 , Edge area 5mm 2 , the calculated deformation deviation percentage mean is 0%, no deformation. According to the result that the deformation deviation percentage mean of channel I area is greater than that of channel II area, III area, edge area and single piece, it is inferred that the deformation of the MCP piece is mainly caused by the inappropriate setting of reduction heating and cooling speed and hydrogen flow rate.

[0108] (6) Batch testing: After a piece of microchannel plate to be tested is tested, the motor drives the screw to move smoothly, driving the quartz boat and the microchannel plate to be tested to move along the quartz boat axis (AB direction). The moving speed of the screw is 40mm / s, and the single moving distance is 20mm. Move the new microchannel plate to be tested to the initial position to be tested, and repeat steps (3) to (5).

[0109] The specific test results of the second MCP to be tested are: the projection area of ​​the strip light after each rotation of 30° is 72mm 2 , that is, S1=S2=S3=S4=S5=S6=S7=0mm 2 According to the formula, the mean percentage deviation of the single-piece deformation variable is calculated as (S1+S2+S3+S4+S5+S6+S7) / (7*72)*100%, and the mean percentage deviation of the single-piece deformation variable is 0, corresponding to a flatness of 0 μm without deformation, which meets the flatness requirements of the microchannel plate for night vision.

[0110] See also Figure 2 , is a schematic diagram of circular microchannel plate surface shape detection, in which Ⅰ, Ⅱ, and Ⅲ are circular partition marks, and the middle shaded part is the projection of the strip light.

[0111] Example 2

[0112] The detection method is the same as that of Example 1, and the detection parameters of Example 2 in Table 1 are used to detect the surface shape of the rectangular microchannel plate.

[0113] See also Figure 3 , is a schematic diagram of rectangular microchannel plate surface shape detection, in which Ⅰ, Ⅱ, Ⅲ are rectangular partition marks, and the middle shadow part is the projection of the strip light;

[0114] In this embodiment, the normal undeformed projected area of ​​the 50mm×25mm rectangular MCP is 150mm 2 The specific test results of the first MCP to be tested are: the projection area of ​​the strip light after each rotation of 15° is 155mm 2 、151mm 2 、154mm 2 、152mm 2 、150mm 2 、145mm 2 、150mm 2 、149mm 2 、146mm 2 、152mm 2 、154mm 2 、150mm 2 , that is, S1 = 5mm 2 、S2=1mm 2 、S3=4mm2 、S4=2mm 2 、S5=0mm 2 、S6=5mm 2 、S7=0mm 2 、S8=1mm 2 、S9=4mm 2 、S10=2mm 2 、S11=4mm 2 、S12=0mm 2 、S13=0mm 2 According to the formula, the average percentage deviation of the single-piece deformation variable is calculated as (S1+S2+…+S13) / (13*150)*100%, which is 1.6%, corresponding to a flatness of 1.6 μm, meeting the flatness requirements of the microchannel plate for night vision.

[0115] For the deformation of each partition, the normal undeformed projection area of ​​channel I is 54mm 2 The specific test results are: the projection area of ​​the strip light after each rotation of 15° is 54mm 2 , that is, SⅠ1=SⅠ2=……SⅠ12=0mm 2 According to the formula, the average percentage deviation of deformation variable in channel I = (SⅠ1+SⅠ2+……+SⅠ13) / (13*54)*100%, the average percentage deviation of deformation variable is 0; for the detection of channel II, III and edge area, the normal undeformed projection area is 50mm in II area. 2 、Zone III 40mm 2 , Edge area 6mm 2 The calculated deformation deviation percentage means are 0% in zone II, 0% in zone III and 1.8% in the hemming zone. According to the results that the deformation deviation percentage means of the single piece and the deformation deviation percentage means of channel zones I, II and III are less than the deformation deviation percentage means of the hemming zone, it is inferred that the deformation of the MCP is mainly caused by the problem of reduction clamping deflection.

[0116] Example 3

[0117] The detection method is the same as that of Example 1, and the detection parameters of Example 3 in Table 1 are used to detect the surface shape of the sector-shaped microchannel plate.

[0118] See also Figure 4 , is a schematic diagram of the surface shape detection of the fan-shaped microchannel plate, in which Ⅰ, Ⅱ, and Ⅲ are the fan-shaped partition marks, and the middle shadow part is the projection of the strip light;

[0119] In this embodiment, the outer arc is 8πmm / the inner arc is 5πmm / the central angle is 60°. The normal undeformed projection area of ​​the fan-shaped MCP is 100mm 2The specific test results of the first MCP to be tested are: the projection area of ​​the strip light after each rotation of 20° is 105mm 2 、112mm 2 、124mm 2 、122mm 2 、130mm 2 , 125mm 2 , 120mm 2 、129mm 2 、136mm 2 、132mm 2 , that is, S1 = 5mm 2 、S2=12mm 2 、S3=24mm 2 、S4=22mm 2 、S5=30mm 2 、S6=25mm 2 、S7=20mm 2 、S8=29mm 2 、S9=36mm 2 、S10=32mm 2 According to the formula, the average percentage deviation of the single-piece deformation variable is calculated as (S1+S2+…+S10) / (10*100)*100%, which is 23.5%, corresponding to a flatness of 23.5 μm, which does not meet the flatness requirements of the microchannel plate for night vision.

[0120] For the deformation of each partition, the normal undeformed projection area of ​​the detection of channel II and III is 35mm in II and 35mm in III respectively. 2 、Zone III 50mm 2 The specific test results are as follows: when the strip light rotates 20°, the average deviation percentage of the deformation amount of channel II and III calculated according to the formula is 22.5% for zone II and 23.6% for zone III respectively; the test of channel zone I and the edge area shows that the normal undeformed projection area is 10mm for zone I. 2 and hemming area 5mm 2 , the mean percentage deviation of deformation variables calculated in zone I and hemming zone is 0%. According to the result that the mean percentage deviation of deformation variables in channel zone II, zone III and single piece is greater than the mean percentage deviation of deformation variables in channel zone I and hemming zone, it is inferred that the deformation of the MCP piece is mainly caused by the matching of materials or structural arrangement in channel zone and hemming zone.

[0121] The present invention improves the detection efficiency and simultaneously distinguishes the slight deformation of the edges of various special-shaped MCPs, providing technical guidance for locating the deformation area and solving the problem.

[0122] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A microchannel plate surface automatic detection system, characterized in that: It includes a carrying platform, a lead screw, a quartz boat, a rotating strip light, and an image acquisition and processing system; A screw rod is provided above the carrying platform, a quartz boat is nested on the screw rod, and the screw rod is connected to a motor; The quartz boat is provided with at least one clamping slot, and the clamping slot is used to clamp the microchannel plate to be tested; The rotating strip light is arranged on one side of the quartz boat, and is used to illuminate the microchannel plate to be tested to form a projection, and the length of the rotating strip light is greater than the maximum size of the microchannel plate to be tested; The image acquisition and processing system is arranged on the other side of the quartz boat, and comprises an image acquisition device and an image processing system, wherein the image acquisition device is used to acquire the projection image of the rotating strip light on the microchannel plate to be tested, and transmit the image to the image processing system in real time; The image processing system realizes the detection of deformation at different positions through color space transformation, binary analysis, contour analysis, line segment detection, precise edge detection based on gradient fitting, and deviation calculation of the projection deformation of the rotating strip light.

2. The microchannel plate surface shape automatic detection system according to claim 1, characterized in that: The bottom of the quartz boat is provided with at least two threaded sleeves, and there are two screw rods, each of which passes through at least one threaded sleeve and is fixedly connected to the quartz boat.

3. The microchannel plate surface automatic detection system according to claim 2, characterized in that: The quartz boat is provided with more than two clamping slots, which are arranged at a certain distance. The microchannel plate to be tested on each clamping slot is placed vertically relative to the supporting platform, and each microchannel plate to be tested can achieve axial movement with the quartz boat.

4. The microchannel plate surface shape automatic detection system according to claim 3, characterized in that: The distance between two adjacent microchannel plates to be tested is 10 to 20 mm.

5. The microchannel plate surface automatic detection system according to any one of claims 1 to 4, characterized in that: The geometric center of the projection of the rotating strip light falls on the geometric center of the microchannel plate to be tested, and the projection length is greater than the maximum dimension of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 2 to 6 mm; The initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. When it starts working, the lamp tube can rotate along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30 degrees every 0.2 seconds. When a microchannel plate detection is completed, the lamp tube rotates 180 degrees.

6. The microchannel plate surface automatic detection system according to claim 5, characterized in that: The lamp tube of the rotating strip light is a white light LED lamp tube; the length of the rotating strip light is 100-200 mm, the width is 10-30 mm, the geometric center of the rotating strip light is 100-200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the geometric centers of the two is 150-200 mm, and the angle θ between the geometric center line of the two and the axial direction of the quartz boat is 45-60°.

7. The microchannel plate surface automatic detection system according to claim 5, characterized in that: The image acquisition device is a high-definition industrial camera. The geometric center of the image acquisition device is 100-200 mm higher than the geometric center of the first microchannel plate to be tested. The distance between the geometric center of the image acquisition device and the geometric center of the first microchannel plate to be tested is 150-200 mm. The angle β between the line connecting the geometric center of the image acquisition device and the geometric center of the first microchannel plate to be tested and the axial direction of the quartz boat is 45-60°.

8. A method for detecting the surface shape of a microchannel plate using the microchannel plate surface shape automatic detection system according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Install the microchannel plate to be tested: Use a multi-slot quartz boat to hold 1 to 100 microchannel plates to be tested. Each microchannel plate to be tested is placed vertically relative to the quartz boat. The threaded sleeve at the bottom of the quartz boat is nested with the screw on the supporting platform, and then tightened by screwing to ensure that the relative position of the quartz boat and the screw is fixed without sliding; (2) Installing a rotating strip light: placing the rotating strip light on one side of the quartz boat, wherein the geometric center of the rotating strip light is 100 to 200 mm higher than the geometric center of the first microchannel plate to be tested, the distance between the two geometric centers is 150 to 200 mm, and the angle θ between the line connecting the two geometric centers and the axial direction of the quartz boat is 45 to 60°; (3) Setting the working parameters of the rotating strip light: adjusting the geometric center of the projection of the rotating strip light to fall on the geometric center of the first microchannel plate to be tested, and the projection length is greater than the maximum size of the microchannel plate to be tested. When the microchannel plate to be tested is not deformed, the projection width is 2 to 6 mm; the initial direction of the rotating strip light is that the lamp tube is perpendicular to the horizontal plane. After starting to work, the lamp tube is rotated clockwise along the plane where the lamp tube is located with the geometric center of the lamp tube as the center of the circle, rotating 5 to 30 degrees every 0.2 seconds, and completing the detection of a microchannel plate to be tested after rotating 180 degrees; (4) Installing an image acquisition device: placing the image acquisition device on the side of the quartz boat, the geometric center of the image acquisition device is 100-200 mm higher than the geometric center of the first microchannel plate to be tested, and the distance is 150-200 mm. The angle β between the line connecting the geometric centers of the two and the axial direction of the quartz boat is 45-60°, so that the projection of the rotating strip light on the microchannel plate to be tested can be completely reflected to the camera. The image acquisition device takes a projection at an interval of 0.2s and transmits the image to the image processing system in real time. After the rotating strip light completes a 180° rotation, the single microchannel plate projection detection image acquisition is completed; (5) The processing process of the image processing system: ① Using OpenCV experimental platform software, the edge shape of the rotating strip light projection in each image is determined through color space transformation, binary analysis, projection contour analysis, line segment detection, and precise edge detection based on gradient fitting; ② The area to be inspected of the microchannel plate is divided into a channel area and an edge area, and the channel area is further divided into area I, area II and area III; ③ The edge shape of the projection of each image is compared with the edge shape of the preset projection without deformation, the deformation deviation of the projection corresponding to different rotation angles of the rotating strip light is calculated, and then the average percentage of the deformation deviation of the single-chip microchannel plate is calculated; According to the partition limit, the edge shape of each partition projection is compared with the edge shape of the preset projection of each zone without deformation, and the deformation deviation of each partition projection corresponding to different rotation angles of the rotating strip light is calculated, and then the average percentage of the deformation deviation of each partition is calculated; ④ Determine the flatness of the single microchannel plate to be tested according to the mean value of the deviation percentage of the single microchannel plate deformation variable; According to the comparison result of the average percentage deviation of the deformation variables of each partition and the average percentage deviation of the deformation variables of the single MCP, the area prone to deformation is judged, and the cause of the deformation of the microchannel plate is judged according to the area prone to deformation; (6) Batch testing: After a piece of microchannel plate to be tested is tested, the motor drives the lead screw to move the quartz boat along its axial direction, and moves a new piece of microchannel plate to be tested to the initial testing position, and repeats steps (3) to (5).

9. The method according to claim 8, characterized in that The moving speed of the screw rod is 20 mm / s to 40 mm / s, and the single moving distance is 10 to 20 mm.

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