Image tube front proximity distance measuring device and measuring method thereof

Abstract

The invention relates to the technical field of double proximity distance control, in particular to an image tube front proximity distance measuring device and a measuring method thereof. Comprising a Y-axis moving module, a Z-axis micrometer moving module, an optical device mounting plate, a spherical hinge, a ball guide rail module, an X-axis moving module, a Z-axis moving module, a black and white camera, a grating ruler module, an infrared light source, a bottom plate, an X-axis module connecting plate, a Y-axis moving module mounting plate and a bare tube tool. According to the principle that the light transmittance of gallium arsenide in the visible light and near-infrared band range reaches 90% or above and is far higher than that of similar materials, and the light transmission wavelength ranges from 850 nm to 1100 nm, light beams with the wavelength ranging from 850 nm to 1100 nm are emitted to an image tube, a gallium arsenide face and a micro-channel plate face are positioned through a black-and-white camera capable of receiving infrared light, and the light transmittance of gallium arsenide in the visible light and near-infrared band range reaches 90% or above. The front proximity distance can be visually measured through the distance difference between the two, and superposition or amplification of a plurality of error sources in indirect measurement is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of double close proximity distance control, and in particular to a device for measuring the close proximity distance in front of an image tube and a method thereof. Background Art

[0002] As a dual close-proximity focusing type, the third-generation photodetector has the advantages of compact structure, small size, light weight and high reliability. It is mainly composed of five parts: GaAs photocathode, first close-proximity focusing electron optical system, MCP, second close-proximity focusing electron optical system and anode. Inside, the MCP is close to the GaAs photocathode and the anode, forming two close-proximity spaces. The GaAs photocathode output surface and the MCP input surface constitute the first close-proximity focusing system, and the MCP output surface and the anode input surface constitute the second close-proximity focusing system. Each part affects the quality of the input image.

[0003] We often call the distance between the photocathode output surface and the MCP input surface the "first close contact distance" or "front close contact", and the distance between the MCP output surface and the anode input surface the "second close contact distance" or "back close contact". In addition to the resolution of the photocathode, MCP, anode and other components themselves affecting the resolution of the photodetector, the control of the double close contact distances largely determines the resolution of the product, and plays a decisive role in the imaging system and device image quality of the third-generation photodetectors.

[0004] For the control of double proximity distances, the industry usually adopts direct measurement method to control the second proximity distance. By using a two-dimensional measuring instrument to test before welding the anode component and then retesting after welding, the measured value is more intuitive and accurate; but the first proximity distance is not convenient to measure directly after the photocathode and the anode component are indium-sealed. Usually, the first proximity distance is obtained by indirect measurement after indium sealing, which is mainly calculated using formulas based on the image tube height, cathode height, height from the microchannel plate support ring to the bottom of the fluorescent screen, and microchannel plate thickness.

[0005] The indirect measurement method requires multiple direct measurements before measurement. The error of each direct measurement will be accumulated and transmitted to the final result, resulting in amplified error of the result. In addition, this method requires designing the measurement process and recording the corresponding data during the preparation of the photocathode and the anode. Compared with direct measurement, it requires more manpower costs and increases the complexity of the operation. Summary of the invention

[0006] 1. Technical issues

[0007] The present invention aims at at least solving the problem of superposition or amplification of multiple error sources in indirect measurement in the prior art.

[0008] Taking advantage of the principle that the transmittance of gallium arsenide in the visible light and near-infrared wavelength ranges is as high as over 90%, far higher than that of similar materials, and the transmission wavelength is in the range of 850nm - 1100nm, an infrared light source projects a light beam with a wavelength in the range of 850nm - 1100nm onto the image tube to be measured. By using a black-and-white camera that can receive infrared light to locate the gallium arsenide surface and the microchannel plate surface, the difference in the distance between the two can directly measure the front proximity distance, avoiding the superposition or amplification of multiple error sources in indirect measurement.

[0009] (2) Technical content

[0010] This solution provides a device for measuring the front proximity distance of an image tube, which is achieved by the following specific technical means: including

[0011] A bottom pedestal, which is a flat structure;

[0012] A Z-axis movement module and a ball screw guide module. The Z-axis guides in the Z-axis movement module and the ball screw guide module are symmetrically fixed at the left and right ends of the rear side of the bottom pedestal; A Y-axis movement module is installed between the sliders on the Z-axis movement module and the sliders on the ball screw guide module;

[0013] An optical device mounting plate is installed on the slider in the Y-axis movement module. A black-and-white camera, a grating scale module, and an infrared light source are all installed on the optical device mounting plate; The infrared light source is used to emit a light beam with a wavelength in the range of 850nm - 1100nm; The black-and-white camera can receive infrared light; The grating scale module is used to record the position of the black-and-white camera;

[0014] An X-axis movement module, whose X-axis slide rail is installed at the center of the top surface of the bottom pedestal, is located below the Y-axis slide rail and is perpendicular to the Y-axis slide rail; A bare tube tooling is installed on the slider in the X-axis movement module, and it is used to place the workpiece to be measured (i.e., the image tube).

[0015] Preferred technical solution one: It also includes a Z-axis micrometer movement module installed on the optical device mounting plate. The black-and-white camera and the head of the grating scale module are installed on the slider in the Z-axis micrometer movement module, while the grating scale of the grating scale module is installed on the optical device mounting plate.

[0016] Preferred technical solution two: It also includes a ball hinge, which is connected between the optical device mounting plate and the infrared light source. The ball hinge is used to finely adjust the direction of the infrared light source beam.

[0017] Preferred technical solution three: The grating scale module is located between the black-and-white camera and the infrared light source.

[0018] The Z-axis moving module, Y-axis moving module, and X-axis moving module cooperate to roughly adjust the relative position between the optical device and the workpiece to be detected. After the complete workpiece to be detected appears in the imaging field of the black and white camera, adjust the position of the ball hinge to align the infrared light source with the workpiece to be detected, and adjust the Z-axis micrometer moving module to focus the black and white camera on the cathode bottom surface and the microchannel plate surface. The difference between the two focusing distances is the front near-contact distance, which is measured and output by the grating scale module. The operation is simple and efficient, reducing the operation complexity. The measurement result can be obtained immediately, and at the same time, semi-automation is achieved, improving the measurement efficiency.

[0019] (3) Technical effects

[0020] Adopting the above structure enables this solution to have the following beneficial effects:

[0021] 1. The tooling uses a 4-axis moving module to ensure that the camera and the light source can better collect the required images;

[0022] 2. The front near-contact distance output by the grating scale module can be used as feedback data for the sealing process in image tube production. During the sealing process, the front near-contact distance of the image tube can be measured by this tooling to be used as a feedback signal in the feedback control of the sealing process, converting the originally used open-loop control in the sealing process into a closed-loop control, improving the production efficiency of the sealing process. Description of the drawings

[0023] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0024] Figure 1 is a schematic diagram of the overall structure of this solution;

[0025] Figure 2 is the front view of this solution;

[0026] Figure 3 is the top view of this solution;

[0027] Figure 4 is a schematic diagram of the measurement method of this solution.

[0028] Among them, 1. Y-axis movement module, 2. Z-axis micrometer movement module, 3. Optical device mounting plate, 4. Ball hinge, 5. Ball rail module, 6. Z-axis rail mounting plate, 7. Support feet, 8. Black and white camera mounting plate, 9. X-axis movement module, 10. Z-axis movement module mounting plate, 11. Z-axis movement module, 12. Black and white camera, 13. Grating scale module, 14. Infrared light source, 15. Bottom pedestal, 16. X-axis module connecting plate, 17. Y-axis movement module mounting plate, 18. Grating scale module mounting plate, 19. Ball hinge mounting L plate, 20. Light source hinge connecting plate, 21. Bare tube tooling, 22. Image tube. Detailed implementation manner

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0030] Please refer to Figures 1 - 3 , an image tube front near-contact distance measuring device. An image tube front near-contact distance measuring device includes a bottom pedestal 15, a Z-axis movement module 11, a ball rail module 5, a Y-axis movement module 1, an optical device mounting plate 3, a black and white camera 12, a grating scale module 13, an infrared light source 14, an X-axis movement module 9, and a bare tube tooling 21, wherein:

[0031] The bottom pedestal 15 serves as an installation surface, and support feet 7 are installed at the four corners of the bottom for support;

[0032] The X-axis movement module 9, its X-axis slide rail is fixedly installed in the positioning groove in the center of the top surface of the bottom pedestal 15 through bolts;

[0033] The bare tube tooling 21 is installed on the X-axis module connecting plate 16 fixed on the slider in the X-axis movement module 9 with bolts. The bare tube tooling 21 is used to place the workpiece to be measured (i.e., the image tube 22), serving as a placement platform adapted to the size of the workpiece to be measured;

[0034] The Z-axis movement module 11 and the ball rail module 5, the Z-axis rails in the Z-axis movement module 11 and the ball rail module 5 are symmetrically fixed at the left and right ends of the rear side of the bottom pedestal 15;

[0035] In one embodiment: The Z-axis guide rail in the Z-axis moving module 11 is vertically installed at the left end of the rear side of the base pedestal 15 with bolts through the Z-axis moving module mounting plate 10 fixedly connected thereto; the Z-axis guide rail in the ball guide rail module 5 is vertically installed at the right end of the rear side of the base pedestal 15 with bolts through the Z-axis guide rail mounting plate 6 fixedly connected thereto, and all mating surfaces use positioning grooves to ensure their perpendicularity and flatness; compared with the positioning threaded holes required for the positioning pin positioning method that need secondary processing, the positioning grooves only need to be processed once to ensure the consistency of processing;

[0036] The Y-axis moving module 1 is installed between the Z-axis moving module 11 and the ball guide rail module 5, and the X-axis moving module 9 is located on the Y-axis moving module 1 and is perpendicular to the Y-axis moving module 1;

[0037] In one embodiment: A Y-axis moving module mounting plate 17 is fixed between the slider in the Z-axis moving module 11 and the slider in the ball guide rail module 5, and the slide rail of the Y-axis moving module 1 is fixed to the Y-axis moving module mounting plate 17 with bolts. The layout of the X-axis moving module 9, the Y-axis moving module 1, and the Z-axis moving module 11 is as Figure 1 shown;

[0038] The optical device mounting plate 3 is fixed to the slider in the Y-axis moving module 1, and the black and white camera 12, the grating scale module 13, and the infrared light source 14 are all installed on the optical device mounting plate 3;

[0039] The infrared light source 14 is used to emit a light beam with a wavelength in the range of 850 nm - 1100 nm; the black and white camera 12 locates the gallium arsenide surface and the microchannel plate surface through the black and white camera 12 that can receive infrared light; the grating scale module 13 is used to record the position of the black and white camera 12;

[0040] In one embodiment: On the optical device mounting plate 3, there are a Z-axis micrometer moving module 2, a grating scale module mounting plate 18, and a ball hinge mounting L plate 19 in sequence from left to right. Among them, the Z-axis guide rails of the ball hinge mounting L plate 19, the grating scale module mounting plate 18, and the Z-axis micrometer moving module 2 are fixed to the optical device mounting plate 3 with bolts. The black and white camera 12 is fixedly installed on the slider of the Z-axis micrometer moving module 2 through the black and white camera mounting plate 8. The grating scale in the grating scale module 13 is fixedly installed on the grating scale module mounting plate 18, and the head of the grating scale in the grating scale module 13 is fixedly installed at a position extending to the left side of the black and white camera mounting plate 8 and close to the grating scale; at the same time, the infrared light source 14 is installed on the ball hinge mounting L plate 19 through the ball hinge 4, that is, the top end of the ball hinge 4 is fixed on the ball hinge mounting L plate 19, and the bottom end is fixedly connected to the infrared light source 14 through the light source hinge connecting plate 20.

[0041] Using the principle that gallium arsenide has a light transmittance of over 90% in the visible and near-infrared wavelength ranges, which is much higher than that of similar materials, and its light transmission wavelength is in the range of 850 nm - 1100 nm, the infrared light source 14 projects a light beam with a wavelength in the range of 850 nm - 1100 nm onto the image tube 22 to be measured. The black-and-white camera 12 that can receive infrared light locates the gallium arsenide surface and the microchannel plate surface, and the difference in the distance between the two can directly measure the front proximity distance, avoiding the superposition or amplification of multiple error sources in indirect measurement.

[0042] Please refer to Figure 1 , as shown in Figure 4, this solution also discloses a method for measuring the front proximity distance of an image tube, including the following steps:

[0043] Step 1, place the image tube 22 on the bare tube tooling 21;

[0044] Step 2, move the slider on the Z-axis moving module 11 to adjust the overall height of the Y-axis moving module 1;

[0045] Move the slider on the Y-axis moving module 1 to adjust the horizontal Y-direction position of the optical device mounting plate 3, that is, adjust the horizontal Y-direction positions of the black-and-white camera 12, the grating scale module 13, and the infrared light source 14;

[0046] Move the slider on the X-axis moving module 9 to adjust the horizontal X-direction position of the bare tube below, so as to adjust the relative positions between the black-and-white camera 12, the grating scale module 13, the infrared light source 14 and the image tube 22 until a complete image tube 22 to be inspected appears in the imaging field of view of the black-and-white camera 12;

[0047] Step 3, adjust the position of the ball hinge 4 so that the infrared light source 14 is aligned with the image tube 22 to be inspected;

[0048] Step 4, make the black-and-white camera 12 focus on the cathode output surface (A surface) by adjusting the Z-axis micrometer moving module 2, and the grating scale module 13 records the current position, denoted as the reference surface;

[0049] Continue to adjust the Z-axis micrometer moving module 2 so that the black-and-white camera 12 focuses on the upper surface of the microchannel plate (B surface). The grating scale module 13 records the current position and outputs the Z-axis distance difference (h2) between the current position and the reference surface. This difference is the front proximity distance (h1) of the image tube 22.

[0050] During the use of this solution, it is necessary to perform daily maintenance on each component according to the formulated maintenance plan to ensure its working state.

[0051] It should be noted that the accuracy of the Z-axis movement module 11, the ball guide rail module 5, the Y-axis movement module 1, and the X-axis movement module 9 mentioned in this embodiment is 1 mm. The stroke of the Z-axis movement module 11, the ball guide rail module 5, and the Y-axis movement module 1 is 180 mm, and the stroke of the X-axis movement module 9 is 80 mm. The accuracy of the Z-axis micrometer movement module 2 is 0.01 mm.

[0052] The specific models of the above Z-axis movement module 11, ball guide rail module 5, Y-axis movement module 1, X-axis movement module 9, Z-axis micrometer movement module 2, black and white camera 12, grating scale module 13, and infrared light source 14, as well as their supporting power supplies and control switches, can also be provided by the manufacturer. The circuits, electronic components, and modules involved are all prior arts, and can be fully realized by those skilled in the art without further elaboration.

[0053] Unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0054] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A near-contact distance measuring device in front of an image tube, comprising a bottom pedestal (15), characterized in that, It further includes a Z-axis moving module (11) and a ball screw guide rail module (5). The Z-axis guide rails in the Z-axis moving module (11) and the ball screw guide rail module (5) are symmetrically fixed at the left and right ends of the rear side of the base pedestal (15); a Y-axis moving module (1), which is installed between the sliders on the Z-axis moving module (11) and the sliders on the ball screw guide rail module (5); an optical device mounting plate (3), which is installed on the slider in the Y-axis moving module (1); a black-and-white camera (12), a grating scale module (13), and an infrared light source (14), all of which are installed on the optical device mounting plate (3); an X-axis moving module (9), which is installed on the top surface of the base pedestal (15) and is located below the Y-axis slide rail; a bare tube tooling (21), which is installed on the slider in the X-axis moving module (9) and is used to place the image tube to be tested (22); The X-axis moving module (9), the Y-axis moving module (1), and the Z-axis moving module (11) cooperate to adjust the positions of the black-and-white camera (12), the grating scale module (13), the infrared light source (14) and the image tube.

2. The near-contact distance measuring device for an image tube according to claim 1, characterized in that It further includes a Z-axis micrometer moving module (2). The Z-axis guide rail of the Z-axis micrometer moving module (2) is fixed on the optical device mounting plate (3). At the same time, the heads of the black-and-white camera (12) and the grating scale module (13) are installed on the slider in the Z-axis micrometer moving module (2), while the grating scale of the grating scale module (13) is installed on the optical device mounting plate (3).

3. The image tube front near-contact distance measuring device according to claim 2, characterized in that, It further includes a ball hinge (4). One end of the ball hinge (4) is fixed on the optical device mounting plate (3), and the other end is used to fix the infrared light source (14).

4. The image tube front near-contact distance measuring device according to claim 1, wherein The infrared light source (14) is used to emit a light beam with a wavelength in the range of 850 nm - 1100 nm.

5. The image intensifier front near-contact distance measuring device according to claim 1, characterized in that, The black-and-white camera (12) can receive infrared light.

6. The near-contact distance measuring device for an image intensifier according to claim 2, characterized in that, The grating scale module (13) is close to the black-and-white camera (12).

7. A method for measuring the front proximity distance of an image tube according to any one of claims 1 to 6, characterized in that, It includes the following steps Step 1, place the image tube (22) on the bare tube tooling (21); Step 2, move the slider on the Z-axis moving module (11) to adjust the overall height of the Y-axis moving module (1); Move the slider on the Y-axis moving module (1) to adjust the horizontal Y-direction position of the optical device mounting plate (3), that is, adjust the horizontal Y-direction positions of the black-and-white camera (12), the grating scale module (13), and the infrared light source (14); Move the slider on the X-axis moving module (9) to adjust the horizontal X-direction position of the bare tube below, so as to adjust the relative positions between the black-and-white camera (12), the grating scale module (13), the infrared light source (14) and the image tube (), until a complete image tube to be inspected (22) appears in the imaging field of view of the black-and-white camera (12); Step 3, adjust the position of the ball hinge (4) so that the infrared light source (14) is aligned with the image tube to be inspected (22); Step 4, make the black-and-white camera (12) focus on the cathode output surface by adjusting the Z-axis micrometer moving module (2), and the grating scale module (13) records the current position, which is denoted as the reference plane; Continue to adjust the Z-axis micrometer moving module (2) so that the black and white camera (12) focuses on the upper surface of the microchannel plate. The grating scale module (13) records the current position and outputs the Z-axis distance difference between the current position and the reference plane. This difference is the front close-proximity distance of the image intensifier tube (22).

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