Imaging system for imaging an object under test

Abstract

This application provides an imaging system for imaging an object under test. The imaging system includes a radiation source, a translation device, and a first imaging unit. The first imaging unit includes at least a first grating and a first detector, and the translation device includes at least a first translation unit. The first detector is configured to receive radiation emitted from the radiation source and passing through at least the object under test and the first grating. The first translation unit is located between the radiation source and the first detector and is configured to carry the object under test and move it linearly along a first direction. The first grating is located between the radiation source and the first translation unit, or between the first translation unit and the first detector.

Description

Technical Field

[0001] This application relates to the field of X-ray imaging technology, and more specifically to an imaging system for imaging an object under test. Background Technology

[0002] X-ray imaging systems typically consist of two main parts: a radiation source and a detector. The radiation source generates radiation (e.g., X-rays), and the detector receives the radiation after it passes through the object under test and converts it into a visual image, which can then be used to reconstruct the internal structural information of the object. To obtain multi-angle projection images of the object under test, a common method is circular orbit imaging, where the radiation source and detector rotate around the object. Existing X-ray imaging systems still have room for improvement in terms of the richness of information and image quality of the acquired images. Summary of the Invention

[0003] This application provides an imaging system for imaging an object under test. The imaging system includes a radiation source, a translation device, and a first imaging unit. The first imaging unit includes at least a first grating and a first detector, and the translation device includes at least a first translation unit. The first detector is configured to receive radiation emitted from the radiation source and passing through at least the object under test and the first grating. The first translation unit is located between the radiation source and the first detector and is configured to carry the object under test and move it linearly along a first direction. The first grating is located between the radiation source and the first translation unit or between the first translation unit and the first detector.

[0004] According to some embodiments of this application, the first grating is located between the X-ray source and the first translation unit, and the first imaging unit further includes: a second grating located between the X-ray source and the first grating; and a third grating located between the first translation unit and the first detector.

[0005] According to some embodiments of this application, at least one of the first grating, the second grating, and the third grating includes a plurality of sub-gratings, the positional orientations of the plurality of sub-gratings being different from each other.

[0006] According to some embodiments of this application, the plurality of sub-gratings includes a first sub-grating and a second sub-grating that are adjacent to each other, the first sub-grating being closer to one end of the second sub-grating, the second sub-grating being closer to one end of the first sub-grating, and the ray source being in the same plane.

[0007] According to some embodiments of this application, the center points of each of the plurality of sub-gratings are located on the same virtual connection line.

[0008] According to some embodiments of this application, the virtual connection line is parallel to the first direction.

[0009] According to some embodiments of this application, the first detector includes a plurality of sub-detectors corresponding to the plurality of sub-gratings, and the positional orientations of the plurality of sub-detectors are different from each other.

[0010] According to some embodiments of this application, each of the plurality of sub-detectors is parallel to the sub-grating corresponding to the sub-detector.

[0011] According to some embodiments of this application, the plurality of sub-gratings are distributed along a first curve that bends in a direction from the ray source toward the first detector.

[0012] According to some embodiments of this application, the first detector includes a plurality of sub-detectors corresponding to the plurality of sub-gratings respectively, the plurality of sub-detectors having different positional orientations, the plurality of sub-detectors being distributed along a second curve, the curvature direction of the second curve being consistent with the first curve.

[0013] According to some embodiments of this application, the first curve includes a first arc centered on the ray source, and the second curve includes a second arc centered on the ray source.

[0014] According to some embodiments of this application, each of the plurality of sub-gratings includes a curved sub-grating that is bent in a direction from the ray source toward the first detector.

[0015] According to some embodiments of this application, each of the plurality of sub-detectors includes a curved sub-detector, the bending direction of which is consistent with the bending direction of the curved sub-grating corresponding to the curved sub-detector.

[0016] According to some embodiments of this application, at least one of the first grating, the second grating, and the third grating includes a curved grating that is bent in a direction from the ray source toward the first detector.

[0017] According to some embodiments of this application, the curved grating includes an arc surface centered on the ray source.

[0018] According to some embodiments of this application, the first detector includes a curved detector, the bending direction of which is consistent with the bending direction of the curved grating.

[0019] According to some embodiments of this application, each of the first grating, the second grating, and the third grating includes a plurality of first ray absorption strips and a plurality of second ray absorption strips, the plurality of first ray absorption strips and the plurality of second ray absorption strips being symmetrical about a central axis located within the grating, and the plurality of first ray absorption strips and the plurality of second ray absorption strips being inclined toward the central axis respectively.

[0020] According to some embodiments of this application, the imaging system further includes a second imaging unit, the second imaging unit including at least a fourth grating and a second detector, the translation device further includes a second translation unit, the second detector being configured to receive rays emitted from the ray source and passing at least through the object under test and the fourth grating, the second translation unit being located between the ray source and the second detector and coupled to the first translation unit, the fourth grating being located between the ray source and the second translation unit or between the second translation unit and the second detector, the second translation unit being configured to carry the object under test and drive the object under test to move linearly along a second direction, the second direction being different from the first direction.

[0021] According to some embodiments of this application, the fourth grating is located between the X-ray source and the second translation unit, and the positional orientation of the fourth grating is different from that of the first grating. The second imaging unit further includes: a fifth grating located between the X-ray source and the fourth grating; and a sixth grating located between the second translation unit and the second detector.

[0022] According to some embodiments of this application, the first direction and the second direction form an acute angle or a right angle.

[0023] According to some embodiments of this application, the radiation source includes a first sub-radiation source and a second sub-radiation source, the first sub-radiation source being configured to emit radiation toward the first, second, and third gratings, and the second sub-radiation source being configured to emit radiation toward the fourth, fifth, and sixth gratings.

[0024] According to some embodiments of this application, the imaging system further includes a second imaging unit, the second imaging unit including at least a fourth grating and a second detector, wherein the second detector is configured to receive rays emitted from the ray source and passing at least through the object under test and the fourth grating, the fourth grating being adjacent to the first grating and having a different orientation than the first grating, wherein the first direction is parallel to the intersection of the plane containing the first grating and the plane containing the fourth grating.

[0025] According to some embodiments of this application, the fourth grating is located between the X-ray source and the first translation unit, and the second imaging unit further includes: a fifth grating located between the X-ray source and the fourth grating; and a sixth grating located between the second translation unit and the second detector.

[0026] According to some embodiments of this application, the second detector is parallel to the fourth grating, and the first detector is parallel to the first grating.

[0027] According to some embodiments of this application, the radiation source includes an X-ray source that emits X-rays.

[0028] These and other advantages of this application will become clear from the embodiments described below, and will be illustrated with reference to the embodiments described below. Attached Figure Description

[0029] Embodiments of this application will now be described in more detail with reference to the accompanying drawings, wherein: Figure 1 The figure shows a partial schematic top view of an imaging system for imaging an object under test according to an embodiment of the present application; Figure 2 The figure shows a partial schematic top view of an imaging system for imaging an object under test according to another embodiment of this application; Figure 3 A partial top view of an imaging system according to another embodiment of this application is schematically illustrated. Figure 4 A partial top view of an imaging system according to another embodiment of this application is schematically illustrated. Figure 5 The figure shows a partial top view of an imaging system according to another embodiment of this application; Figure 6 A top view of a single curved subgrating in an imaging system according to another embodiment of this application is schematically illustrated; Figure 7 A schematic side view of a single sub-grating in an imaging system according to another embodiment of this application; Figure 8 The figure shows a partial top view of a grating in an imaging system according to another embodiment of this application; Figure 9 The figure shows a partial top view of an imaging system according to another embodiment of this application; Figure 10 The figure shows a partial top view of an imaging system according to another embodiment of this application; Figure 11The figure shows a partial top view of an imaging system according to another embodiment of this application; Figure 12 The illustration shows a partial top view of an imaging system according to another embodiment of this application. Detailed Implementation

[0030] The following description provides specific details of various embodiments of this application to enable those skilled in the art to fully understand and implement the various embodiments of this application. It should be understood that the technical solutions of this application can be implemented without some of these details. In some cases, this application does not show or describe in detail some well-known structures or functions to avoid such unnecessary descriptions obscuring the description of the embodiments of this application. The terminology used in this application should be understood in its broadest and most reasonable manner, even when used in connection with specific embodiments of this application.

[0031] Embodiments of this application provide an imaging system for imaging an object under test. The imaging system includes a radiation source, a translation device, and a first imaging unit. The first imaging unit includes at least a first grating and a first detector, and the translation device includes at least a first translation unit. The first detector is configured to receive radiation emitted from the radiation source and passing through at least the object under test and the first grating. The first translation unit is located between the radiation source and the first detector and is configured to carry the object under test and move it linearly along a first direction. The first grating is located between the radiation source and the first translation unit, or between the first translation unit and the first detector.

[0032] Figure 1 and Figure 2 Different examples of imaging systems are illustrated. For example... Figure 1 or Figure 2As shown, the imaging system includes a radiation source 10, a translation device, and a first imaging unit. The translation device includes a first translation unit 20, and the first imaging unit includes at least a first grating 30 and a first detector 40. The translation device mentioned herein refers to a device capable of driving the object under test to move linearly along a certain direction. The translation device can be implemented as a lead screw and rail linear drive device or a synchronous belt linear drive device. For example, the translation device may include a drive motor, a lead screw, a nut, a linear guide rail, and a moving stage. The drive motor drives the lead screw to rotate, and the lead screw engages with the nut, converting the rotational motion into linear motion. The nut drives the moving stage to move linearly along the linear guide rail. The object under test can be placed on the moving stage. Alternatively, the translation device includes a drive motor, a driving wheel, a driven wheel, and a transmission belt. The driving wheel can be coupled to the rotating shaft of the drive motor, thereby rotating under the drive of the drive motor. The driven wheel is driven by the driving wheel through the transmission belt and follows the rotation of the driving wheel. The object under test can be placed on the transmission belt, and when the motor operates, causing its rotating shaft to rotate in a certain direction, the transmission belt drives the object under test to move linearly. The translation device can also be implemented in other forms; for example, the translation device may also include a cylinder linear drive. The embodiments of this application do not impose any limitation on the specific implementation of the translation device.

[0033] like Figure 1 or Figure 2 As shown, the translation device includes at least a first translation unit 20. Examples of the first translation unit 20 include, but are not limited to, a conveyor belt, a moving stage, etc. When the imaging system is running, the object under test OB is placed on the first translation unit 20. The first detector 40 receives rays emitted from the ray source 10 that pass at least through the object under test OB and the first grating 30. The first translation unit 20 is located between the ray source 10 and the first detector 40, carries the object under test OB, and drives the object under test OB to move linearly along the first direction D1. Figure 1 As shown, the first grating 30 is located between the first translation unit 20 and the first detector 40, or, as... Figure 2 As shown, the first grating 30 is located between the X-ray source 10 and the first translation unit 20. Examples of the X-ray source 10 include, but are not limited to, X-ray sources, and this application does not impose specific limitations on the type of X-ray source. For example, the X-ray source may be a microfocus X-ray source, a nanofocus X-ray source, a synchrotron radiation source, an X-ray tube, etc.

[0034] Therefore, the imaging system provided in this embodiment of the application includes a grating, which, compared to conventional imaging systems, can obtain richer image information about the object under test. Furthermore, when scanning and detecting the object under test, the imaging system only requires the object to move along a straight line, without requiring the grating, X-ray source, or detector to rotate or move. Therefore, compared to conventional circular orbit imaging systems, it avoids the problems of difficulty in fixing the grating and grating deformation that may occur during rotation. Moreover, the scanning speed for the object under test is not limited by the slip ring rotation speed in the circular orbit imaging system, thereby achieving more efficient scanning and detection of the object under test.

[0035] According to some embodiments of this application, a first grating in the imaging system is located between the X-ray source and the first translation unit. The first imaging unit further includes: a second grating located between the X-ray source and the first grating; and a third grating located between the first translation unit and the first detector. Figure 3 A top view structural diagram of an imaging system according to an embodiment of this application is schematically illustrated. Figure 3 As shown, the first imaging unit includes a first grating 30, a second grating 50, and a third grating 60. The second grating 50 is located between the X-ray source 10 and the first grating 30, and the third grating 60 is located between the first translation unit 20 and the first detector 40. In this embodiment, the second grating 50 can also be called a source grating, which can convert the light emitted from the X-ray source 10 into multiple coherent line light sources; the first grating 30 can also be called a phase modulation grating, which can cause X-rays to diffract and interfere, forming interference fringes; the third grating 60 can also be called an analysis grating, which can convert the phase change and small-angle scattering information in the X-ray interference fringes passing through the object under test OB into a light intensity signal that can be collected by the first detector. Based on this imaging system, an absorption image reflecting the X-ray attenuation characteristics of the object under test (corresponding to the linear attenuation coefficient μ), a phase image with higher contrast for weakly absorbing materials (corresponding to the refractive index reduction δ in the complex refractive index), and a small-angle scattering image reflecting the mesoscale microstructure information of the object under test (corresponding to the linear diffusion coefficient ζ) can be obtained. Thus, the image of the object under test obtained based on the imaging system contains richer image information.

[0036] In some embodiments, at least one of the aforementioned first, second, and third gratings includes a plurality of sub-gratings, the sub-gratings having different orientations from each other. Different orientations of the sub-gratings within the same grating mean that these sub-gratings do not overlap and are not located in the same plane. In other words, in this embodiment, a single, relatively large grating is replaced by a plurality of relatively small sub-gratings. This reduces the amount of rays incident on the grating at a relatively large tilt angle, allowing more rays to be incident on the grating at a smaller tilt angle or perpendicular to the grating surface. The tilt angle refers to the angle between a line connecting the ray source to any point on the grating surface and a line connecting the ray source to the grating surface perpendicular to it. This reduces diffraction fringe distortion and phase error caused by tilted incidence, thereby improving the quality of the image of the object being measured obtained by the imaging system.

[0037] Figure 4 A schematic top view of an imaging system according to an embodiment of this application is shown, but no translation device is illustrated in the figure. Figure 4 As shown, the first, second, and third gratings each include multiple sub-gratings. For example, the first grating includes four sub-gratings 30a, 30b, 30c, and 30d; the second grating includes four sub-gratings 50a, 50b, 50c, and 50d; and the third grating includes four sub-gratings 60a, 60b, 60c, and 60d. The sub-gratings within the same grating have different orientations, so that rays emitted from the X-ray source 10 will be incident on each sub-grating at a relatively small tilt angle, thereby improving the image quality of the object under test obtained by the imaging system. In this specification, the term "position orientation" used when describing an element in the imaging system refers to the position of the element and its orientation or orientation at that position; position orientation can also be referred to as pose. More specifically, in the embodiments of this application, the position orientation of a grating, sub-grating, detector, or sub-detector refers to the position of the grating, sub-grating, detector, or sub-detector in the two-dimensional plane containing the top view of the imaging system and their orientation or orientation at the corresponding position. Therefore, the term “different orientations” as used in this article means that the two or more elements referred to by the term are different from each other in both position and orientation.

[0038] In some embodiments, the two end faces of two adjacent sub-gratings in the same grating and the ray source are approximately in the same plane. For example, as Figure 4As shown, the first grating comprises multiple sub-gratings, including a first sub-grating 30a and a second sub-grating 30b adjacent to each other. The first sub-grating 30a has an end A1 near the second sub-grating 30b, the second sub-grating 30b has an end A2 near the first sub-grating 30a, and the ray source 10 is on the same plane. It can be understood that in this case, the ray source 10 is equivalent to a small point. The first and second sub-gratings can be offset from each other and separated, with a relatively large gap between them, such as... Figure 4 The first sub-grating 30a and the second sub-grating 30b are in the middle. The first sub-grating and the second sub-grating can also be in contact with each other through their adjacent ends, for example, sub-grating 50b and sub-grating 50c.

[0039] According to some embodiments of this application, the center points of each sub-grating in a plurality of sub-gratings of the same grating lie on the same virtual connecting line. For example, Figure 4 The center points of each sub-grating 60a, 60b, 60c, and 60d in the third sub-grating are C1, C2, C3, and C4, respectively, and these center points are located on the same virtual connecting line. Similarly, the center points of each sub-grating in the first grating can also be on the same virtual connecting line, and the center points of each sub-grating in the second sub-grating can also be on the same virtual connecting line. In some embodiments, this virtual connecting line is parallel to the direction of movement of the object under test in the imaging system, i.e., the aforementioned first direction.

[0040] In some embodiments, the first detector includes a plurality of sub-detectors corresponding to the aforementioned plurality of sub-gratings, wherein the positional orientations of the plurality of sub-detectors are different from each other. For example, Figure 4 The diagram illustrates a first detector comprising four sub-detectors 40a, 40b, 40c, and 40d. These four sub-detectors correspond to respective sub-gratings in the third grating and receive rays passing through sub-gratings 60a, 60b, 60c, and 60d, respectively. In some embodiments, each sub-detector of the first detector is parallel to the sub-grating corresponding to it. Figure 4 In the example, the first, second, and third gratings each contain the same number of sub-gratings, and the number of sub-gratings is also equal to the number of sub-detectors contained in the first detector. Each sub-detector is parallel not only to its corresponding sub-grating in the third grating, but also to its corresponding sub-gratings in the first and second gratings. For example, sub-detectors 40a, sub-grating 60a, sub-grating 30a, and sub-grating 50a are parallel to each other. Accordingly, the centers of each sub-detector in the first detector can also lie on the same virtual connecting line.

[0041] According to another embodiment of this application, a plurality of sub-gratings in a first grating, a second grating, or a third grating are distributed along a first curve, which curves in a direction from the ray source toward the first detector. In this embodiment, each sub-grating has a small size in a plane parallel to the aforementioned first direction, and the sub-gratings in the same grating are distributed along the first curve, such that the grating as a whole forms a curved surface structure. For example, in some embodiments, the first curve may include a first circular arc centered on the ray source. See also Figure 5 The illustration shows a partial top view of an imaging system according to another embodiment of this application. For simplicity, the translation device is not shown. The first grating 30, the second grating 50, and the third grating 60 each include a plurality of sub-gratings distributed along three curves, each curve comprising three first circular arcs with different radii centered on the X-ray source. This embodiment facilitates the incident rays emitted from the X-ray source onto each sub-grating at a relatively small angle of inclination, thereby improving the quality of the image of the object under test obtained by the imaging system.

[0042] Accordingly, in some embodiments, the first detector includes a plurality of sub-detectors corresponding to the plurality of sub-gratings, the sub-detectors having different orientations and being distributed along a second curve whose curvature is consistent with the first curve. This second curve may include a second arc centered on the X-ray source. For example, Figure 5 The first detector 40 can be formed by multiple digital detectors distributed along a second circular arc centered on the X-ray source 10.

[0043] According to another embodiment of this application, each of the first, second, and third gratings is not a planar grating, but is bent into a curved shape. That is, each of the first, second, and third gratings includes a curved sub-grating that is bent in a direction from the ray source toward the first detector. Figure 6 A schematic diagram of a single curved subgrating is shown from top view. For example... Figure 6 As shown, the sub-grating includes a substrate SB and multiple radiation-absorbing strips 100, 200, 300, and 400 arranged on the substrate SB. The area between two adjacent radiation-absorbing strips is a radiation-transmitting region. The substrate is formed of a material that allows radiation to pass through. Figure 6As shown, the substrate SB has a curved shape, so that each of the X-ray absorption strips 100, 200, 300, and 400 also moves closer to or tilts towards the central region of the sub-grating. This allows more X-rays to pass through the X-ray transmission area and through the sub-grating, thereby improving the utilization rate of the X-rays emitted from the X-ray source and enhancing the intensity of the X-rays sensed or received by the first detector. This improves the detection sensitivity and efficiency of the imaging system for the object under test. In addition, this embodiment also allows the X-rays emitted from the X-ray source to be incident on each sub-grating at a relatively small tilt angle, thereby improving the quality of the obtained image of the object under test. Figure 7 A side view of a single sub-grating is schematically illustrated. Accordingly, each of the plurality of sub-detectors forming the first detector includes a curved sub-detector, the curvature direction of which is consistent with the curvature direction of the curved sub-grating corresponding to the curved sub-detector, thereby improving the efficiency of the first detector in receiving or sensing rays.

[0044] In another embodiment, at least one of the first, second, and third gratings is a single, integral curved grating, rather than a composite of multiple sub-gratings, which curves in a direction from the ray source toward the first detector. (See again...) Figure 5 , Figure 5 At least one of the first grating 30, the second grating 50, and the third grating 60 includes an integral curved grating, that is, at least one of the first grating 30, the second grating 50, or the third grating 60 is a single integral curved grating, which may include an arcuate surface centered on the X-ray source 10. In some embodiments, the first detector 40 includes a curved detector, the curvature direction of which coincides with the curvature direction of the curved grating 30, 50, or 60. This embodiment has the characteristic of the first grating, second grating, or third grating discussed above including multiple curved sub-gratings (e.g., such as...). Figure 6 The advantages of the embodiments shown are similar to those of the embodiments illustrated, and will not be repeated here.

[0045] Figure 8 The illustration shows a partial top view of a grating in an imaging system according to another embodiment of this application. In this embodiment, the substrate SB of the grating is not curved but remains flat, and the individual ray absorption strips of the grating converge or tilt towards the central region of the grating. In some embodiments, each of the first, second, and third gratings includes a plurality of first ray absorption strips and a plurality of second ray absorption strips, the plurality of first ray absorption strips and the plurality of second ray absorption strips being symmetrical about a central axis located within the grating, and the plurality of first ray absorption strips and the plurality of second ray absorption strips tilting towards the central axis, respectively. For example, Figure 8The diagram illustrates the first ray absorption bars 100 and 200, the second ray absorption bars 300 and 400, and the central axis AX. The area between any adjacent ray absorption bars among the multiple first and second ray absorption bars is the ray transmission region. In reality... Figure 6 The curved gratings or curved sub-gratings shown also have similar properties, therefore, Figure 6 The diagram also illustrates the central axis AX. Using such a grating allows more rays to pass through the ray-transmitting area, thereby increasing the utilization rate of rays emitted from the ray source, enhancing the intensity of rays sensed or received by the first detector, and improving the detection sensitivity and efficiency of the imaging system for the object under test. Figure 8 The grating structure shown can be used as the first grating, second grating, or third grating in an imaging system, and can also be applied to the sub-gratings mentioned in the foregoing embodiments.

[0046] According to another embodiment of this application, the imaging system includes a first imaging unit and a second imaging unit. The second imaging unit includes at least a fourth grating and a second detector. The translation device in the imaging system also includes a second translation unit. The second detector is configured to receive rays emitted from the ray source and passing through at least the object under test and the fourth grating. The second translation unit is located between the ray source and the second detector and coupled to the first translation unit. The fourth grating is located between the ray source and the second translation unit, or between the second translation unit and the second detector. The second translation unit is configured to carry the object under test and drive the object under test to move linearly along a second direction, which is different from the first direction. Thus, the imaging system provided by this embodiment allows the object under test to be scanned and detected by the first imaging unit when it moves linearly along the first direction, and by the second imaging unit when it moves linearly along the second direction. Since the first and second directions are different, the first and second imaging units can scan and detect the object under test from different angles, thereby compensating for the insufficient sampling angle range of a single imaging unit, reducing data loss in the obtained image, and improving the quality of the final image of the object under test.

[0047] For example, in the previously discussed embodiments, the sampling angle range for the first imaging unit to scan and detect the object under test is α. To obtain better image quality of the object under test, a larger value for the sampling angle range α is desired, but this would result in an excessively large size for the first detector. Figure 9 In this embodiment, the first imaging unit includes a first grating 301, a second grating 501, a third grating 401, and a first detector 401. The object to be measured OB is moved linearly along a first direction D1 by a first translation unit. The sampling angle range of the first imaging unit for the object to be measured is... The second imaging unit includes a fourth grating 302 and a second detector 402, and the translation device also includes a second translation unit ( Figure 9 (Not shown in the diagram) The structure of the second translation unit can be similar to that of the first translation unit described above. For example, the second translation unit includes a conveyor belt or a moving stage. The fourth grating 302 is located between the X-ray source 10 and the second translation unit. The second imaging unit may also include a fifth grating 502 and a sixth grating 602. The fifth grating 502 is located between the X-ray source 10 and the fourth grating 302, and the sixth grating 602 is located between the second translation unit and the second detector 402. The second detector 402 receives X-rays emitted from the X-ray source 10 and passing through the fifth grating 502, the fourth grating 302, the object OB on the second translation unit, and the sixth grating 602. The fourth, fifth, and sixth gratings mentioned here are functionally similar to the first, second, and third gratings in the aforementioned embodiments, respectively. However, the positional orientation of the fourth, fifth, and sixth gratings is different from that of the first, second, and third gratings, respectively. The second translation unit is coupled to the first translation unit. During imaging system operation, the second translation unit moves the object under test OB linearly along the second direction D2. In this embodiment, the second direction D2 is perpendicular to the first direction D1. In other embodiments, the second direction may intersect the first direction to form other angles. Figure 9 As shown, the sampling angle range for the second imaging unit to scan and detect the object OB under test is as follows: Therefore, the sampling angle range of the entire imaging system for the object under test is... and The sum of all values. Using the imaging system provided in this embodiment of the application, a large sampling angle range for the object under test can be achieved using a relatively small detector, thereby improving the accuracy of the obtained image of the object under test.

[0048] Figure 10 The figure shows a partial top view of an imaging system provided according to another embodiment of this application. Figure 10 Implementation examples and Figure 9 The main difference lies in the radiation source. For example... Figure 10 As shown, the radiation source includes a first sub-radiation source 101 and a second sub-radiation source 102. The first sub-radiation source 101 is configured to emit radiation toward a first grating 301, a second grating 501, and a third grating 601, and the second sub-radiation source 102 is configured to emit radiation toward a fourth grating 302, a fifth grating 502, and a sixth grating 602. Furthermore, in Figure 9 In this embodiment, the first grating 301 and the fourth grating 302 are in contact with each other, the second grating 501 and the fifth grating 502 are in contact with each other, the third grating 601 and the sixth grating 602 are in contact with each other, and the first detector 401 and the second detector 402 are in contact with each other. Figure 10 In this configuration, the first grating 301 and the fourth grating 302, the second grating 501 and the fifth grating 502, the third grating 601 and the sixth grating 602, and the first detector 401 and the second detector 402 can be separated from each other by a large gap.

[0049] In other embodiments, the imaging system may include a greater number of imaging units, i.e., the imaging system may include N imaging units, where N is an integer greater than or equal to 2. For example, in addition to the aforementioned first and second imaging units, the imaging system may also include a third imaging unit... and so on up to the Nth imaging unit. Each imaging unit has a similar structure. For example, each imaging unit includes three gratings (functionally corresponding to the aforementioned first, second, and third gratings, respectively) and a detector, but the orientation of the gratings and detector differs in different imaging units. For example, Figure 11 An exemplary structure of an imaging system comprising N imaging units is illustrated.

[0050] like Figure 11 As shown, the first imaging unit includes a first grating 301, a second grating 501, a third grating 601, and a first detector 401. The i-th imaging unit includes gratings 30i, 50i, and 60i corresponding to the first grating 301, the second grating 501, and the third grating 601, respectively, and an i-th detector 40i. The N-th imaging unit includes gratings 30n, 50n, and 60n corresponding to the first grating 301, the second grating 501, and the third grating 601, respectively, and an n-th detector 40n. Correspondingly, the translation device may include a first translation unit, a second translation unit, ..., and an Nth translation unit. When the imaging system is running, these translation units can drive the object under test OB to move linearly in different directions sequentially. For example, Figure 11 The diagram illustrates five different linear movement directions: D1, D2, D3, D4, and D5. The directions of linear movement of the object OB by two adjacent translation units intersect to form an acute angle. (For example...) Figure 11 As shown, the sampling angle range for the first imaging unit to scan and detect the object OB under test is as follows: The sampling angle range for the i-th imaging unit to scan and detect the object OB under test is: The sampling angle range for the Nth imaging unit to scan and detect the object OB under test is: Therefore, the sampling angle range of the entire imaging system for the object under test is... , and The sum of all values. Based on this embodiment, a larger sampling angle range for the object under test can be achieved using a smaller detector, thereby improving the accuracy of the obtained image of the object under test.

[0051] According to another embodiment of this application, the imaging system further includes a first imaging unit and a second imaging unit. The second imaging unit includes at least a fourth grating and a second detector. The second detector is configured to receive rays emitted from the ray source and passing through at least the object under test and the fourth grating. The fourth grating is adjacent to the first grating, and its positional orientation differs from that of the first grating. A first direction is parallel to the intersection of the plane containing the first grating and the plane containing the fourth grating. In this embodiment, the object under test is moved linearly in the first direction by a translation device, and the first direction is parallel to the intersection of the plane containing the first grating and the plane containing the fourth grating. Therefore, the first imaging unit and the second imaging unit can simultaneously scan and detect the object under test from different perspectives, enabling a one-time scanning and detection of a large-sized object under test. In some embodiments, the fourth grating is located between the ray source and the first translation unit. The second imaging unit further includes a fifth grating located between the ray source and the fourth grating, and a sixth grating located between the second translation unit and the second detector. Further, the imaging system may include a greater number of imaging units, each with a similar structure, except that the positional orientation of the gratings in different imaging units differs from each other.

[0052] Figure 12 The illustration shows a schematic top view of the imaging system according to this application. For simplicity, the translation device is not shown. Figure 12 As shown, the first imaging unit includes a first grating 301, a second grating 501, a third grating 601, and a first detector 401. The second imaging unit includes a fourth grating 302, a fifth grating 502, a sixth grating 602, and a second detector 402. The imaging system also includes a third imaging unit, which includes gratings 303, 503, and 603, and a detector 403. The fourth grating 302, fifth grating 502, and sixth grating 602 functionally correspond to the first grating 301, second grating 501, and third grating 601, respectively. Similarly, gratings 303, 503, and 603 functionally correspond to the first grating 301, second grating 501, and third grating 601, respectively. Figure 12 As shown, the gratings are arranged perpendicular to the plane of the paper; however, the orientations of the corresponding gratings differ in different imaging systems. For example, the first grating 301 in the first imaging unit and the fourth grating 302 in the second imaging unit are adjacent but intersect at an obtuse angle; the second grating 501 and the fifth grating 502 are adjacent but intersect at an obtuse angle; and the third grating 601 and the sixth grating 602 are adjacent but intersect at an obtuse angle. Figure 12In the example, the intersection line of the plane containing the first grating 301 and the plane containing the fourth grating 302 is perpendicular to the paper. When the imaging system is running, the first translation unit of the translation device moves the object under test OB in a straight line in a direction perpendicular to the paper, that is, the first direction D1 is parallel to the intersection line of the plane containing the first grating 301 and the plane containing the fourth grating 302. Different imaging units can simultaneously scan and detect the object under test from different perspectives, that is, different imaging units can scan and detect different parts of the object under test. The sampling angle range of the first imaging unit, the second imaging unit, or the third imaging unit is relatively small; however, three imaging units can achieve a larger sampling angle range. Based on the imaging system provided in this embodiment, even if the volume or size of the object under test OB is large, a one-time scan detection of the object under test can be completed, achieving highly efficient scan detection of large-sized objects under test.

[0053] exist Figure 12 In some embodiments, the gratings and detectors in each imaging unit can be parallel to each other. For example, the first grating 301, the second grating 501, the third grating 601 and the first detector 401 are parallel to each other.

[0054] The foregoing has described some possible embodiments of this application; however, the scope of protection of this application is limited only by the appended claims. Although individual features may be included in different claims, they may be advantageously combined, and the order of features in the claims does not imply that the features must operate in any particular order. Furthermore, in the claims, the word "comprising" does not exclude other elements or steps.

Claims

1. An imaging system for imaging an object to be measured, comprising: X-ray source; Translation device; as well as First imaging unit The first imaging unit includes at least a first grating and a first detector, and the translation device includes at least a first translation unit. The first detector is configured to receive rays emitted from the ray source that pass through at least the object under test and the first grating. The first translation unit is located between the ray source and the first detector and is configured to carry the object under test and move the object under test linearly along a first direction. The first grating is located between the radiation source and the first translation unit or between the first translation unit and the first detector.

2. The imaging system of claim 1, wherein, The first grating is located between the ray source and the first translation unit, and the first imaging unit further includes: A second grating is located between the ray source and the first grating; and The third grating is located between the first translation unit and the first detector.

3. The imaging system of claim 2, wherein, At least one of the first grating, the second grating, and the third grating includes a plurality of sub-gratings, the positional orientations of the plurality of sub-gratings being different from each other.

4. The imaging system of claim 3, wherein, The plurality of sub-gratings includes a first sub-grating and a second sub-grating that are adjacent to each other, with the first sub-grating near the end of the second sub-grating, the second sub-grating near the end of the first sub-grating, and the ray source being on the same plane.

5. The imaging system according to claim 3, characterized in that, The center points of each of the multiple sub-gratings are located on the same virtual connecting line.

6. The imaging system of claim 5, wherein, The virtual connection line is parallel to the first direction.

7. The imaging system of claim 3, wherein, The first detector includes multiple sub-detectors corresponding to the multiple sub-gratings, and the multiple sub-detectors have different positional orientations.

8. The imaging system of claim 7, wherein, Each of the plurality of sub-detectors is parallel to the sub-grating corresponding to the sub-detector.

9. The imaging system of claim 3, wherein, The plurality of sub-gratings are distributed along a first curve that bends in the direction from the ray source toward the first detector.

10. The imaging system of claim 9, wherein, The first detector includes multiple sub-detectors corresponding to the multiple sub-gratings respectively. The multiple sub-detectors have different positional orientations and are distributed along a second curve. The curvature direction of the second curve is consistent with that of the first curve.

11. The imaging system of claim 10, wherein, The first curve includes a first arc centered on the ray source, and the second curve includes a second arc centered on the ray source.

12. The imaging system of claim 10, wherein, Each of the plurality of sub-gratings includes a curved sub-grating that is bent in a direction from the ray source toward the first detector.

13. The imaging system of claim 12, wherein, Each of the plurality of sub-detectors includes a curved sub-detector, the curvature direction of which is consistent with the curvature direction of the corresponding curved sub-grating.

14. The imaging system of claim 2, wherein, At least one of the first grating, the second grating, and the third grating includes a curved grating that is bent in a direction from the ray source toward the first detector.

15. The imaging system of claim 14, wherein, The curved grating includes an arc surface centered on the ray source.

16. The imaging system of claim 14, wherein, The first detector includes a curved detector, the bending direction of which is consistent with the bending direction of the curved grating.

17. The imaging system of claim 2, wherein, Each of the first, second, and third gratings includes a plurality of first ray absorption bars and a plurality of second ray absorption bars, the plurality of first ray absorption bars and the plurality of second ray absorption bars being symmetrical about a central axis located within the grating, and the plurality of first ray absorption bars and the plurality of second ray absorption bars being inclined toward the central axis respectively.

18. The imaging system of any of claims 1-17, wherein, The imaging system further includes a second imaging unit, which includes at least a fourth grating and a second detector; the translation device further includes a second translation unit. The second detector is configured to receive rays emitted from the ray source and passing through at least the object under test and the fourth grating. The second translation unit is located between the ray source and the second detector and coupled to the first translation unit. The fourth grating is located between the ray source and the second translation unit, or between the second translation unit and the second detector. The second translation unit is configured to carry the object under test and drive the object under test to move linearly along a second direction, which is different from the first direction.

19. The imaging system of claim 18, wherein, The fourth grating is located between the ray source and the second translation unit, and the orientation of the fourth grating is different from that of the first grating. The second imaging unit further includes: A fifth grating, located between the ray source and the fourth grating; and The sixth grating is located between the second translation unit and the second detector.

20. The imaging system of claim 18, wherein, The first direction and the second direction form an acute angle or a right angle.

21. The imaging system of claim 18, wherein, The radiation source includes a first sub-radiation source and a second sub-radiation source. The first sub-radiation source is configured to emit radiation toward the first, second, and third gratings, and the second sub-radiation source is configured to emit radiation toward the fourth, fifth, and sixth gratings.

22. The imaging system of any of claims 1-17, wherein, The imaging system further includes a second imaging unit, which includes at least a fourth grating and a second detector, wherein the second detector is configured to receive rays emitted from the ray source and passing through at least the object under test and the fourth grating, the fourth grating being adjacent to the first grating and having a different orientation than the first grating, wherein the first direction is parallel to the intersection of the plane containing the first grating and the plane containing the fourth grating.

23. The imaging system of claim 22, wherein, The fourth grating is located between the ray source and the first translation unit, and the second imaging unit further includes: A fifth grating, located between the ray source and the fourth grating; and The sixth grating is located between the second translation unit and the second detector.

24. The imaging system of claim 18 or 22, wherein the second detector is parallel to the fourth grating and the first detector is parallel to the first grating.

25. The imaging system of any of claims 1-17, wherein, The radiation source includes an X-ray source that emits X-rays.

Images