A collimating device and food detection X-ray equipment

Abstract

The present application relates to food quality detection technical field, especially to a kind of collimating device and food detection X-ray equipment.Wherein, collimating device is used to limit and collimate the linear beam emitted by ray tube, including front collimator, middle collimator and rear collimator, front collimator is located at the light outlet of ray tube, and the outlet end of front collimator is provided with filter assembly, filter assembly includes filter carrier, filter carrier is provided with a plurality of filter pieces, to obtain the same energy, wavelength uniformity required for detection of ray photon;The first end of middle collimator is fixedly connected with front collimator, and the second end is aligned with the object to be detected, to shield the ray, limit the emission direction of ray and block scattered ray;Rear collimator is located between the object to be detected and linear array camera, which includes collimator base material, a plurality of grooves are arranged on the collimator base material, each groove is equidistantly distributed with the focus of ray tube as the center, and a grid is arranged in the groove to block, filter and absorb scattered ray.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food quality detection technology, and in particular to a collimating device and a food detection X-ray equipment. BACKGROUND

[0002] With the increasing demand for food quality, the level of food quality control is continuously improved at home and abroad, and the demand for non-destructive testing X-ray real-time imaging detection equipment is increasing in the market. Non-destructive testing X-ray real-time imaging detection equipment is suitable for foreign matter detection of food and medicine, quality detection of electronic components, lithium batteries and PCB boards, and has a very wide range of applications.

[0003] The X-ray real-time imaging detection equipment on the market currently has two defects: (1) based on the current process level, the focal point size of the X-ray tube must exist, and according to the different manufacturing levels, the focal point size is also different, which results in that the X-ray light source usually has a certain area, so that the imaging system made by using the light source produces a half-shadow area in the imaging process, the image edge is blurred, and the definition is low; (2) in the imaging system with X-ray as the excitation source, there is a scattering phenomenon, which affects the imaging quality. These defects result in low detection accuracy, unstable detection accuracy, unclear imaging and the like of the X-ray real-time imaging detection equipment, and the foreign matters in the final product cannot be detected completely, especially in the food industry, these defects often bring very serious safety hazards, economic losses, quality complaints and even production suspension and other consequences to manufacturers. SUMMARY

[0004] Based on the above problems, one object of the present application is to provide a collimating device that limits and collimates X-ray beams and absorbs scattered rays to meet the detection needs.

[0005] Another object of the present application is to provide a food detection X-ray equipment that improves the detection accuracy and imaging quality to meet the food quality detection requirements.

[0006] To achieve the above objects, on the one hand, the present application adopts the following technical solutions:

[0007] A collimating device for defining and collimating the beam emitted by a ray tube, comprising a front collimator, a middle collimator and a rear collimator arranged in sequence between the ray tube and a linear array camera, the front collimator being located at the light outlet of the ray tube, and the outlet end of the front collimator being provided with a filter assembly, the filter assembly comprising a filter carrier, the filter carrier being provided with a plurality of filter pieces to obtain the same energy and uniform wavelength of the detected ray photons; the first end of the middle collimator is fixedly connected with the front collimator, and the second end is aligned with the object to be detected, so as to shield the rays, limit the emission direction of the rays and block the scattered rays; the rear collimator is located between the object to be detected and the linear array camera, and comprises a collimator base material, the collimator base material is provided with a plurality of grooves, each groove is equidistantly distributed around the focal point of the ray tube, and a grid is arranged in each groove to block, filter and absorb the scattered rays.

[0008] In particular, the front collimator is made of H62 alloy and processed by CNC, and a flat cone port for limiting the emission direction of the rays is arranged on the front collimator, the inlet length of the flat cone port is 50mm, the collimating slit width is 5mm, and the beam limiting angle is 42°.

[0009] In particular, the filter pieces of different materials and thicknesses are selected according to the object to be detected, and the characteristic formula of the filter piece is I=I0e -ux , wherein I is the original ray intensity, I0 is the filtered ray intensity, u is the thickness of the filter piece, x is the absorption coefficient of the material to the rays, and the rays penetrating the filter piece are soft rays with a wavelength of 0.062nm to 0.012nm.

[0010] In particular, the filter assembly further comprises a bracket fixed on the middle collimator, the bracket is provided with a lead screw driven by a servo motor, guide rails are arranged on both sides of the lead screw, a lead screw slider is mounted on the lead screw in a matched manner, the lead screw slider slides along the guide rails, and the filter carrier is mounted on the lead screw slider.

[0011] In particular, a switch sensing sheet is mounted on the lead screw slider, a single-shaft base is arranged on one side of the guide rail, and a sensing switch is mounted on the single-shaft base and located on both sides of the switch sensing sheet to limit the stroke of the lead screw slider, and a protective cover plate covering the filter assembly is further arranged on the bracket.

[0012] In particular, the middle collimator is made of steel plates which are welded together, high-temperature molten lead water is poured between the steel plates, and then the middle collimator is processed by CNC, and a collimating slit for limiting the emission direction of the rays and blocking the scattered rays is arranged on the end face of the second end of the middle collimator, and the width of the collimating slit is 3mm.

[0013] In particular, the collimator base material is made of a radiation-transmitting material, the grid is made of a scattered ray absorbing material, and the thickness of the grid is 10um, the grid is embedded in the groove of the collimator base material by epoxy glue, and the characterization parameters of the grid are grid density and grid ratio Wherein d is the thickness dimension of the grid, D is the pitch of the adjacent grids, and h is the height dimension of the grid.

[0014] In particular, the effective size of the rear collimator is Wherein f1 is the lower limit distance of the applied grid, f2 is the upper limit distance of the applied grid, f c is the convergence distance, V1 is the loss of the original ray intensity at the lower limit distance and is less than 40% of the original ray intensity, and C is the distance from the edge of the effective area to the center line.

[0015] In another aspect, the present application employs the following technical solutions:

[0016] A food detection X-ray device, comprising a feeding conveyor belt for conveying the detected object, a ray tube and a line array camera are correspondingly arranged above and below the feeding conveyor belt, and the above-mentioned collimating device is further included, X-rays emitted by the ray tube pass through the front collimator, the filtering assembly, the middle collimator, the detected object, the feeding conveyor belt, the rear collimator and the line array camera in sequence, and finally an image is presented through computer processing.

[0017] In particular, a rack is further included, the middle collimator is fixed to the top of the rack, the line array camera is fixed to the bottom of the rack, the feeding conveyor belt passes through the rack, the ray tube presses the front collimator and is fixed on the middle collimator, a supporting plate is arranged in the rack and between the feeding conveyor belt and the line array camera, and the rear collimator is fixed on the supporting plate.

[0018] To sum up, the present application has the following advantages compared with the prior art:

[0019] 1) The X-ray imaging detection device for the food industry increases the electrically adjustable filtering assembly at the front collimator, selects the corresponding filter according to different products, so as to obtain X photons with the same energy and uniform wavelength required for product detection, improve the image contrast, and improve the imaging quality;

[0020] 2) The front collimator and the middle collimator are applied to limit the emission direction of X-rays, reduce the miscellaneous rays and scattered rays that make the image unclear, and improve the safety protection;

[0021] 3) The rear collimator with the grid is adopted to block, filter and absorb the scattered X-rays, and the imaging quality is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a front view of the food detection X-ray device provided by the embodiment of the present application;

[0023] Figure 2 is an exploded view of the food detection X-ray device provided by the embodiment of the present application;

[0024] Figure 3 is a light path schematic diagram of X-rays in a food detection X-ray equipment provided by an embodiment of the present application;

[0025] Figure 4 is a structural schematic diagram of a filter assembly in a collimation device provided by an embodiment of the present application;

[0026] Figure 5 is a structural schematic diagram of a rear collimator in a collimation device provided by an embodiment of the present application.

[0027] in the figure:

[0028] 1-front collimator;

[0029] 2-middle collimator;

[0030] 3-rear collimator; 31-collimator base material; 32-groove; 33-bucky;

[0031] 4-x-ray tube;

[0032] 5-filter assembly; 51-bracket; 52-filter carrier; 521-filter; 53-servo motor; 54-screw rod; 55-guide rail; 56-screw rod sliding block; 57-switch induction sheet; 58-induction switch; 59-protection cover plate;

[0033] 6-detected object;

[0034] 7-linear array camera;

[0035] 8-feeding conveyor belt;

[0036] 9-rack; 91-pallet. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar parts or parts having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0038] In the description of the present application, unless explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, it can be mechanically connected, or it can be electrically connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the description of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature. The technical solutions of the present application are further illustrated below by specific embodiments in conjunction with the drawings.

[0040] Please refer to Figures 1 to 5 The preferred embodiment shown provides a collimation device for defining and collimating the beam emitted by the ray tube 4, which includes a front collimator 1, a middle collimator 2 and a rear collimator 3 arranged in sequence between the ray tube 4 and the linear array camera 7.

[0041] The front collimator 1 is located at the light outlet of the ray tube 4 and is made of H62 alloy through CNC machining, and a flat cone port for limiting the emission direction of the rays is arranged thereon. The inlet length of the flat cone port is 50 mm, the collimation slit width is 5 mm, and the beam limiting angle is 42°. The sizes can be designed and adjusted according to the parameters of the equipment.

[0042] A filter assembly 5 is arranged at the outlet end of the front collimator 1, which is shown in detail in Figure 4 The filter assembly 5 includes a bracket 51 and a filter carrier 52. The bracket 51 is fixed to the middle collimator 2. A lead screw 54 driven by a servo motor 53 is arranged on the bracket 51. Guide rails 55 are arranged on both sides of the lead screw 54. A lead screw sliding block 56 is fitted and arranged on the lead screw 54 and slides along the guide rails 55. The filter carrier 52 is arranged on the lead screw sliding block 56. Further, a switch sensing sheet 57 is arranged on the lead screw sliding block 56. A single-axis base is arranged on one side of the guide rail 55. Sensing switches 58 are arranged on the single-axis base and on both sides of the switch sensing sheet 57 to limit the stroke of the lead screw sliding block 56. A protective cover plate 59 is further arranged on the bracket 51 to cover the filter assembly 5.

[0043] A plurality of filter sheets 521 are arranged in the filter carrier 52 to obtain rays with the same energy and uniform wavelength required for detection. Specifically, filter sheets 521 of different materials and thicknesses are selected according to the object 6 to be detected. The characteristic formula of the filter sheet 521 is I = I0e -ux where I is the original ray intensity, I0 is the filtered ray intensity, u is the filter thickness, and x is the material absorption coefficient of the rays. The rays that pass through the filter sheet 521 are soft rays with a wavelength of 0.062 nm to 0.012 nm.

[0044] Wherein, the first end of the middle collimator 2 is fixedly connected with the front collimator 1, and the second end is aligned with the object 6, and the middle is a hollow structure without shielding, limiting the direction of the ray and blocking the scattered ray.

[0045] The middle collimator 2 is a steel-lead steel structure, and the inner and outer steel plates are welded after being poured with high-temperature molten lead between the steel plates, and then processed by CNC. The second end of the middle collimator 2 is provided with a collimating slot for limiting the direction of the ray and blocking the scattered ray. The width of the collimating slot is 3mm, which can be adjusted according to the parameters of the equipment.

[0046] Wherein, the rear collimator 3 is located between the object 6 and the linear array camera 7, and details are shown in Figure 5 , which comprises a collimator base material 31, and a plurality of grooves 32 are arranged on the collimator base material 31, and each groove 32 is equidistantly distributed with the focal point of the ray tube 4 as the center. A line filter 33 is arranged in the groove 32 to block, filter and absorb scattered rays.

[0047] The collimator base material 31 is made of radiation-transmitting material, which is made of polymethyl methacrylate (PMMA), carbon fiber, aluminum and several combinations thereof; the line filter 33 is T-shaped, which is a scattered ray absorbing material, which is lead, tungsten and the like that can block and absorb scattered X-rays, and is made by mechanical grinding, 3D printing and the like, and the thickness is 10um, and is inlaid in the groove 32 of the collimator base material 31 by epoxy glue.

[0048] In particular, the effective size of the rear collimator 3 is Wherein f1 is the lower limit distance of the application of the line filter 33, f2 is the upper limit distance of the application of the line filter 33, f c is the convergence distance, V1 is the loss of the original ray intensity at the lower limit distance and is less than 40% of the original ray intensity, and C is the distance from the edge of the effective area to the center line.

[0049] The characterization parameters of the line filter 33 are the grid density The grid ratio Wherein d is the thickness dimension of the line filter 33, D is the distance between adjacent line filters 33, and h is the height dimension of the line filter 33.

[0050] For this purpose, please refer to Figure 1 and Figure 2As shown, the embodiment also provides a food detection X-ray equipment, comprising a feeding conveyor belt 8 for conveying the detected object 6, the above-mentioned collimating device and a rack 9, a ray tube 4 and a linear array camera 7 are correspondingly arranged above and below the feeding conveyor belt 8, the ray tube 4 is pressed on the middle collimator 2 by a screw, the middle collimator 2 is fixed on the top of the rack 9 by a screw, the linear array camera 7 is fixed on the bottom of the rack 9 by a screw, the feeding conveyor belt 8 passes through the rack 9, a supporting plate 91 is arranged in the rack 9 and between the feeding conveyor belt 8 and the linear array camera 7, and the rear collimator 3 is fixed on the supporting plate 91.

[0051] For details Figure 3 The X-rays emitted by the ray tube 4 pass through the front collimator 1, the filtering assembly 5, the middle collimator 2, the detected object 6, the feeding conveyor belt 8 and the rear collimator 3 in sequence to the linear array camera 7, and finally present an image through computer processing, so as to realize imaging detection.

[0052] In summary, the collimating device removes the expected low-energy rays by using the electrically adjusted filtering assembly, reduces the influence of the focal point size of the ray tube on the imaging quality by using the specially designed front collimator, middle collimator and rear collimator, blocks, filters and absorbs scattered X-rays, improves the image contrast, and thus significantly improves the detection stability and detection accuracy of the X-ray real-time imaging detection equipment, thereby meeting the needs of food quality inspection.

[0053] The above embodiments only illustrate the basic principles and characteristics of the present application, and the present application is not limited by the above embodiments, and various changes and changes can be made without departing from the spirit and scope of the present application, and these changes and changes all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A collimating device for defining and collimating a beam of light emitted from a ray tube, characterized in that, This includes a front collimator, a middle collimator, and a rear collimator sequentially positioned between the X-ray tube and the linear array camera. The precollimator is made of H62 alloy and CNC machined. It has a flat conical opening for limiting the direction of X-ray emission. The entrance length of the flat conical opening is 50 mm, the collimation slit width is 5 mm, and the beam limiting angle is 42°. The precollimator is located at the exit port of the X-ray tube, and a filter assembly is provided at the exit end of the precollimator. The filter assembly includes a filter carrier, in which a plurality of filters are arranged to obtain X-ray photons with the same energy and uniform wavelength required for detection. The collimator is made by welding steel plates together and then casting molten lead at high temperature between the steel plates, followed by CNC machining. The second end face of the collimator is provided with a collimation slit to limit the direction of radiation emission and block scattered rays. The collimation slit is 3mm wide. The first end of the collimator is fixed to the front collimator, and the second end is aligned with the object being inspected to shield radiation, limit the direction of radiation emission, and block scattered rays. The collimator is located between the object being inspected and the linear array camera. It includes a collimator substrate with a plurality of grooves on it. Each groove is equidistantly distributed around the focal point of the X-ray tube. A filter grid is provided in the groove. The filter grid is made of a scattering-absorbing material with a thickness of 10 μm and is embedded in the groove of the collimator substrate with epoxy adhesive to block, filter and absorb scattered rays.

2. The collimation device according to claim 1, characterized in that: Different materials and thicknesses of filters are selected according to the object being inspected. The characteristic formula of the filter is I = I0e -ux Where I is the intensity of the original radiation, I0 is the intensity of the filtered radiation, u is the thickness of the filter, x is the absorption coefficient of the material for radiation, and the radiation passing through the filter is soft radiation with a wavelength between 0.062 nm and 0.012 nm.

3. The collimation device according to claim 1, characterized in that: The filtering assembly also includes a bracket fixed to the collimator, a lead screw driven by a servo motor is provided on the bracket, guide rails are provided on both sides of the lead screw, a lead screw slider is installed on the lead screw, the lead screw slider slides along the guide rails, and the filter carrier is installed on the lead screw slider.

4. The collimation device according to claim 3, characterized in that: A switch sensor is installed on the lead screw slider, and a single-axis base is provided on one side of the guide rail. Inductive switches are installed on the single-axis base and on both sides of the switch sensor to limit the stroke of the lead screw slider. A protective cover plate is also provided on the bracket to cover the filter component.

5. The collimation device according to claim 1, characterized in that: The collimator substrate is made of a radiation-transmitting material, and the characterization parameter of the filter grid is the grid density. Grid ratio Where d is the thickness of the grid, D is the spacing between adjacent grids, and h is the height of the grid. The effective size of the rear collimator is: Where f1 is the lower limit distance of the applied filter grid, f2 is the upper limit distance of the applied filter grid, and f c V1 is the convergence distance, V1 is the loss of the original ray intensity at the lower limit distance and is less than 40% of the original ray intensity, and C is the distance from the edge of the effective area to the center line.

6. A food inspection X-ray device, comprising a feed conveyor belt for transporting the inspected object, wherein X-ray tubes and line array cameras are respectively arranged above and below the feed conveyor belt, characterized in that, It also includes the collimation device as described in any one of claims 1-5, wherein the X-rays emitted from the X-ray tube pass sequentially through the front collimator, the filter assembly, the middle collimator, the object under inspection, the feed conveyor belt, and the rear collimator to the line scan camera, and are finally presented as an image after computer processing.

7. The food testing X-ray equipment according to claim 6, characterized in that: It also includes a frame, the central collimator is fixed to the top of the frame, the line scan camera is fixed to the bottom of the frame, the feed conveyor belt passes through the frame, the X-ray tube presses against the front collimator and is fixed on the central collimator, a support plate is provided in the frame and located between the feed conveyor belt and the line scan camera, and the rear collimator is fixed on the support plate.

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