Scintillator array, X-ray line sensor, X-ray imaging system, method for manufacturing a scintillator array, and image processing method using an X-ray imaging system.

Abstract

This enables higher resolution and higher sensitivity in X-ray line sensors. [Solution] A scintillator array 1 is composed of a plurality of scintillator pixels 2 that convert X-rays into light, wherein the plurality of scintillator pixels 2 are arranged in a straight line by partition walls 3 at equal intervals, and the widths of the first side walls 4 and the second side walls 5 at both ends are different, and when two scintillator arrays 1 are placed on top of each other in opposite directions, the scintillator pixels 2 of one scintillator array 1 and the scintillator pixels 2 of the other scintillator array 1 are offset by half a pixel.

Description

Technical Field

[0001] The present invention relates to a scintillator array, an X-ray line sensor, an X-ray imaging system, a method for manufacturing a scintillator array, and an image processing method using an X-ray imaging system.

Background Art

[0002] X-ray line sensors are used in a wide range of fields such as baggage inspection in the security field, non-destructive inspection and food inspection in the industrial field. X-ray line sensors have a need for high resolution, and for this purpose, fine pitch conversion that narrows the pitch width of the scintillator pixels constituting the X-ray line sensor is known. However, when the fine pitch conversion is advanced, while high resolution can be obtained, the sensitivity decreases because the X-ray detection area becomes small. Patent Document 1 discloses an optical line sensor that performs "pixel shift" in which two line sensors are arranged and the pixels of each line sensor are shifted as an example for achieving high resolution and high sensitivity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although it is disclosed that pixel shift is performed in an optical line sensor, the application of pixel shift to an X-ray line sensor has not been considered. Therefore, there is room for improvement in realizing high resolution and high sensitivity in an X-ray line sensor.

[0005] The present invention provides a scintillator array, an X-ray line sensor, an X-ray imaging system, a method for manufacturing a scintillator array, and an image processing method using the X-ray imaging system, which enable higher resolution and higher sensitivity of X-ray line sensors. [Means for solving the problem]

[0006] One aspect of the present invention is, A scintillator array comprising multiple scintillator pixels that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first and second side walls at both ends are different. When two of the aforementioned scintillator arrays are arranged in opposite directions and overlapping each other, the scintillator pixels of one scintillator array and the scintillator pixels of the other scintillator array are configured to be offset by half a pixel.

[0007] Furthermore, other embodiments of the present invention include: A scintillator array comprising multiple scintillator pixels that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first and second side walls at both ends are different. When the width of the first side wall is W1, the width of the second side wall is W2 which is smaller than the width of the first side wall, the width of the partition wall is W3, and the width of the scintillator pixel is T, W1 + T / 2 = W2 + T + W3 / 2 It is configured to satisfy the following conditions.

[0008] Furthermore, other embodiments of the present invention include: A photodetector for detecting scintillation light emitted by the above-mentioned scintillator array, A substrate on which the aforementioned photodetector is mounted, This is an X-ray line sensor.

[0009] Furthermore, other embodiments of the present invention include: An X-ray line sensor comprising a scintillator array composed of multiple scintillator pixels, The aforementioned X-ray line sensor comprises a first X-ray line sensor array and a second X-ray line sensor array arranged in parallel. The scintillator array of the first X-ray line sensor array and the scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel.

[0010] Furthermore, other embodiments of the present invention include: The above-mentioned X-ray line sensor, A signal processing circuit that processes the measurement signal measured by the aforementioned X-ray line sensor and converts it into an image, Equipped with, This is an X-ray imaging system.

[0011] Furthermore, other embodiments of the present invention include: The above method for manufacturing a scintillator array, A partition wall forming step in which partition walls are formed at equal intervals relative to the scintillator block, A side wall forming step in which a first side wall and a second side wall with different side wall widths are formed relative to the scintillator block, It is equipped with.

[0012] Furthermore, other embodiments of the present invention include: An image processing method using the above-mentioned X-ray imaging system, A first image acquisition step involves acquiring an image captured at a predetermined timing, A second image acquisition step involves acquiring an image captured at a timing corresponding to a position shifted by 1 / 2 pixel relative to one pixel in the scanning direction, The system comprises the first image acquisition step, the second image acquisition step, and an image generation step that performs image generation processing based on the images acquired in the first image acquisition step and the second image acquisition step. [Effects of the Invention]

[0013] According to the present invention, it is possible to achieve higher resolution and higher sensitivity of the X-ray line sensor.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram for explaining the scintillator array 1 in the embodiment. [Figure 2] It is a diagram showing an example in which two scintillator arrays 1 are arranged with a half-pixel shift. [Figure 3] It is a flowchart for explaining an example of a method for manufacturing the scintillator array 1. [Figure 4] It is a flowchart for explaining another example of a method for manufacturing the scintillator array 1. [Figure 5] It is a diagram for explaining an example of a method for manufacturing the scintillator array 1 in FIG. 3. [Figure 6] It is a diagram for explaining an example of a method for manufacturing the scintillator array 1 in FIG. 4. [Figure 7] It is a diagram for explaining an example of a vertical-incidence type X-ray line sensor 10. [Figure 8] It is a diagram for explaining an example of a horizontal-incidence type X-ray line sensor 10. [Figure 9] It is a diagram for explaining an example when a plurality of scintillator arrays 1 are arranged in each X-ray line sensor row 10a, 10b in the vertical-incidence type X-ray line sensor 10. [Figure 10] It is a diagram for explaining an example when a plurality of scintillator arrays 1 are arranged in each X-ray line sensor row 10a, 10b in the horizontal-incidence type X-ray line sensor 10. [Figure 11] It is a diagram for explaining an example when a configuration including a first scintillator array 1a and a second scintillator array 1b is provided in each X-ray line sensor row 10a, 10b in the vertical-incidence type X-ray line sensor 10. [Figure 12]This figure illustrates an example of a configuration in a horizontal incidence type X-ray line sensor 10 in which each X-ray line sensor row 10a, 10b includes a first scintillator array 1a and a second scintillator array 1b. [Figure 13] This figure illustrates another example of a horizontal incidence type X-ray line sensor 10, in which each X-ray line sensor row 10a, 10b includes a first scintillator array 1a and a second scintillator array 1b. [Figure 14] This is a schematic diagram showing an example of an X-ray imaging system 100. [Figure 15] This flowchart shows an example of an image processing method using the X-ray imaging system 100. [Figure 16] This is a diagram illustrating an example of an image processing method. [Figure 17] This figure illustrates another example of the sidewall formation step S2 in the manufacturing method of the scintillator array 1. [Modes for carrying out the invention]

[0015] Hereinafter, an embodiment of the scintillator array, X-ray line sensor, X-ray imaging system, method for manufacturing the scintillator array, and image processing method using the X-ray imaging system of the present invention will be described based on the attached drawings.

[0016] [Scintillator array] First, the configuration of the scintillator array 1 will be described. Figure 1 shows an example of the scintillator array 1 in an embodiment. The scintillator array 1 is composed of a plurality of scintillator pixels 2 that convert X-rays into light. In Figure 1, an example of a scintillator array 1 composed of six scintillator pixels 2 is shown. Note that the number of scintillator pixels 2 included in the scintillator array 1 is not limited to six and may be any number. Furthermore, the scintillator array 1 may be a fine-pitch scintillator array with a relatively narrow pitch width of the scintillator pixels 2, or a rough-pitch scintillator array with a relatively wide pitch width.

[0017] The scintillator array 1 is linearly arranged by partitioning a plurality of scintillator pixels 2 at equal intervals by partition walls 3, and is configured such that the widths of the first side wall 4 and the second side wall 5 at both ends are different. This is to facilitate alignment when two scintillator arrays 1 described later are stacked.

[0018] Specifically, as shown in FIG. 1, a first side wall 4 and a second side wall 5 with different side wall widths are formed at both ends of the scintillator pixels 2 arranged at equal intervals. In the example shown in FIG. 1, the width of the first side wall 4 is larger than the width of the second side wall 5. Note that the width of the first side wall 4 and the width of the second side wall 5 may be configured such that the width of the second side wall 5 is larger than the width of the first side wall 4.

[0019] Also, such a relationship is, for example, when the width of the first side wall 4 is W1, the width of the second side wall 5 is W2 (W2 < W1) smaller than the width W1 of the first side wall 4, the width of the partition wall 3 is W3, and the width of the scintillator pixel 2 is T, W1 + T / 2 = W2 + T + W3 / 2 is configured to satisfy the relationship. That is, it is configured such that the length from the first side wall 4 shown in FIG. 1 to the dashed line L1 is equal to the length from the second side wall 5 to the chain double-dashed line L2.

[0020] Thus, the scintillator array 1 in the embodiment has different side wall widths at both ends, and the shape of the side wall is an asymmetric shape.

[0021] And in the embodiment, two scintillator arrays 1 configured as described above are arranged. Specifically, as shown in FIG. 2, two scintillator arrays 1 are arranged so as to be stacked and in opposite directions. As a result, the scintillator pixels 2 of one scintillator array 1 and the scintillator pixels 2 of the other scintillator array 1 are shifted by half a pixel.

[0022] Thus, when two scintillator arrays 1 are arranged in a superimposed configuration with one of the two scintillator arrays 1 facing in the opposite direction, a configuration shifted by half a pixel can be easily constructed simply by aligning the two scintillator arrays 1 based on their external shapes. In other words, in the case of conventionally known scintillator array configurations, when superimposing two scintillator arrays and shifting the pixels by half a pixel, it is necessary to adjust the position of one of the scintillator arrays by half a pixel while adjusting the narrow pitch width, which is not an easy task. In contrast, as described above, the scintillator array 1 in the embodiment is composed of scintillator arrays 1 with different sidewall widths at both ends, so a configuration shifted by half a pixel can be constructed simply by inverting one of the two scintillator arrays 1 and aligning the end faces of the two scintillator arrays 1. Therefore, a pixel shift of half a pixel can be easily performed.

[0023] [Manufacturing method for scintillator arrays] Next, a method for manufacturing the scintillator array 1 configured as described above will be explained. Figures 3 and 4 are flowcharts showing an example of a method for manufacturing the scintillator array 1. The method for manufacturing the scintillator array 1 comprises a partition wall formation step S1 and a side wall formation step S2. The side wall formation step S2 also includes a groove cutting step S20 (see Figure 3) or a grooving step S21 (see Figure 4).

[0024] The partition wall formation step S1 is a process of forming equally spaced partition walls 3 on the scintillator block 6. Here, the scintillator block 6 is a scintillator in a state where the scintillator pixels 2, partition walls 3, first sidewalls 4, and second sidewalls 5 described above have not been formed, and its size may be arbitrary. In this partition wall formation step S1, equally spaced grooves are formed on the scintillator block 6 in such a state, for example by cutting grooves at equal intervals. Then, partition walls 3 are formed by pouring resin, for example, into each of the cut grooves (see Figure 5).

[0025] The sidewall formation step S2 is a process of forming the first sidewall 4 and the second sidewall 5, which have different sidewall widths, relative to the scintillator block 6. Specifically, the sidewall formation step S2 involves performing either the grooving step S20 or the grooving step S21.

[0026] The grooving step S20 is a process of forming the first side wall 4 and the second side wall 5 by cutting grooves of different widths at both ends of the scintillator block 6. For example, as shown in Figure 5, grooves are cut at both ends of the scintillator block 6 so that the first side wall 4 and the second side wall 5 are of a predetermined width, and the first side wall 4 and the second side wall 5 are formed by pouring resin into each groove. It is preferable that the pouring of resin in the partition wall formation step S1 and the pouring of resin in the grooving step S20 be performed simultaneously. In the example shown in Figure 5, once the partition wall 3, the first side wall 4, and the second side wall 5 are formed, the scintillator block 6 can be cut with a dicer or the like, for example along the arrows along the dashed lines, to generate multiple small pieces of scintillator array 1. In the example shown in Figure 5, four scintillator arrays 1 are generated.

[0027] The order of the partition wall formation step S1 and the side wall formation step S2, which is achieved by the groove cutting step S20, may be reversed or performed simultaneously.

[0028] The side wall formation step S2 may be implemented by the application step S21 instead of the grooving step S20. The application step S21 is a process of applying first side walls 4 and second side walls 5 to both ends of a scintillator block 6 in which partition walls 3 are formed at equal intervals and both ends are exposed (see Figure 6(a)). Here, "apply" means, for example, to form first side walls 4 and second side walls 5 of different widths by attaching reflective films of different thicknesses to both ends, as shown in Figure 6(b), or to form first side walls 4 and second side walls 5 of different widths by coating with reflective layers of different thicknesses instead of reflective films. It is preferable that the reflective film and reflective layer are made of the same material as the partition walls 3.

[0029] Furthermore, the partition wall 3, the first side wall 4, and the second side wall 5, which are formed respectively, function as reflective materials.

[0030] By forming the first side wall 4 and the second side wall 5 in the application step S21, the first side wall 4 and the second side wall 5 can be formed with greater precision than, for example, the groove cutting step S20 described above.

[0031] [X-ray line sensor] As described above, the scintillator array 1 is used in the X-ray line sensor 10. Figures 7 and 8 show an example of the X-ray line sensor 10 using the scintillator array 1 described above. Here, the X-ray line sensor 10 includes the scintillator array 1, a photodetector 11 that detects the scintillation light emitted by the scintillator array 1, and a substrate 12. The photodetector 11 is provided on the substrate 12, and the scintillator array 1 is placed on top of the photodetector 11. As the photodetector 11 is provided on the substrate 12 as described above, in the example of Figures 7 and 8, the photodetector 11 and the substrate 12 are shown together under a single leader line.

[0032] In the examples shown in Figures 7 and 8, the X-ray line sensor 10 is composed of two rows of X-ray line sensors. Here, one row of X-ray line sensors is defined as the first X-ray line sensor row 10a, and the other row of X-ray line sensors is defined as the second X-ray line sensor row 10b. The X-ray line sensor 10 is configured such that the first X-ray line sensor row 10a and the second X-ray line sensor row 10b are arranged in parallel, and the scintillator array of the first X-ray line sensor row 10a and the scintillator array of the second X-ray line sensor row 10b are offset by half a pixel. The first X-ray line sensor row 10a and the second X-ray line sensor row 10b are composed of, for example, the scintillator array 1 described above.

[0033] Figure 7(a) is a perspective view showing an example of a "perpendicular incidence type" X-ray line sensor 10 in which X-rays are incident on the substrate 12 from a direction perpendicular to the substrate. In Figure 7(a), the thick arrow indicates the direction of X-ray incidence. Figure 7(b) shows the first X-ray line sensor array 10a and the second X-ray line sensor array 10b as viewed from the vertical. As shown in Figure 7(b), the scintillator array 1 of the first X-ray line sensor array 10a and the scintillator array 1 of the second X-ray line sensor array 10b are configured to be shifted by half a pixel by aligning one end face and arranging them in opposite directions. In other words, since the first X-ray line sensor array 10a and the second X-ray line sensor array 10b have similar configurations, a state shifted by half a pixel can be created simply by aligning the end faces and reversing one of the X-ray line sensor arrays. This makes it easy to construct an X-ray line sensor 10 with a pixel shift of half a pixel.

[0034] Figure 8(a) is a perspective view showing an example of a "horizontally incident type" X-ray line sensor 10 in which X-rays are incident on the substrate 12 from a horizontal direction. In Figure 8(a), the thick arrow indicates the direction of X-ray incidence. Figure 8(b) shows the first X-ray line sensor array 10a and the second X-ray line sensor array 10b as viewed from the horizontal direction. In the example shown in Figure 8(b), similar to the example in Figure 7, the scintillator array 1 of the first X-ray line sensor array 10a and the scintillator array 1 of the second X-ray line sensor array 10b are configured to be shifted by half a pixel by aligning one end face and arranging them in opposite directions. In other words, since the first X-ray line sensor array 10a and the second X-ray line sensor array 10b have similar configurations, a state shifted by half a pixel can be created simply by aligning the end faces and reversing one of the X-ray line sensor arrays. This makes it easy to construct an X-ray line sensor 10 with a pixel shift of half a pixel.

[0035] In the examples shown in Figures 7 and 8 above, the configuration included one scintillator array 1 in each of the first X-ray line sensor array 10a and the second X-ray line sensor array 10b. However, the X-ray line sensor 10 may include multiple scintillator arrays 1 in both the first X-ray line sensor array 10a and the second X-ray line sensor array 10b. Such a situation may be envisioned, for example, when the size of the subject being irradiated with X-rays is large.

[0036] Figure 9(a) shows an example of the "perpendicular incidence type" X-ray line sensor 10 described above, where one X-ray line sensor row includes multiple scintillator arrays 1. As shown here, the first X-ray line sensor row 10a includes, for example, four scintillator arrays 1. Similarly, the second X-ray line sensor row 10b includes, for example, four scintillator arrays 1. The four scintillator arrays 1 of the first X-ray line sensor row 10a and the four scintillator arrays 1 of the second X-ray line sensor row 10b are arranged in opposite directions with one end face aligned, resulting in a half-pixel offset. In this way, even with a configuration in which multiple scintillator arrays 1 are included in the X-ray line sensor rows 10a and 10b, an X-ray line sensor 10 with a half-pixel offset can be easily constructed by arranging the four scintillator arrays 1 of the first X-ray line sensor row 10a and the four scintillator arrays 1 of the second X-ray line sensor row 10b in opposite directions.

[0037] On the other hand, when the first X-ray line sensor array 10a and the second X-ray line sensor array 10b are configured to include multiple scintillator arrays 1, a gap will be created between the scintillator pixels 2 of one scintillator array 1 and the scintillator pixels 2 of the other scintillator array 1 in the portion where the scintillator arrays 1 are connected. Such gaps will result in pitch jumps when an X-ray transmission image is generated, potentially resulting in an inconsistent image. Therefore, in this embodiment, virtual data 2a is generated for the gaps between scintillator pixels that occur when multiple scintillator arrays 1 are connected. Figure 9(b) shows the X-ray line sensor 10 with virtual data 2a generated for the gaps between scintillator pixels. The virtual data 2a uses, for example, data from scintillator pixels 2 adjacent to each other across the gap. This is because generating virtual data 2a using data from adjacent scintillator pixels 2 allows for the generation of highly accurate virtual data 2a. This virtual data 2a is generated, for example, by the control unit 50 described later.

[0038] Furthermore, as shown in Figures 10(a) and 10(b), the same configuration as in the example in Figure 9 may also be adopted for the "horizontal incidence type" X-ray line sensor 10. A detailed explanation is provided above using Figure 9, so that explanation will be omitted here.

[0039] Furthermore, in the first X-ray line sensor row 10a and the second X-ray line sensor row 10b, the configuration including multiple scintillator arrays 1 may consist only of scintillator arrays 1 with different widths between the first sidewall 4 and the second sidewall 5, as described above, or it may include other scintillator arrays with the same width between the first sidewall 4 and the second sidewall 5. Specifically, it may include "other scintillator arrays" in which multiple scintillator pixels 2 are arranged in a straight line by partition walls 3 at equal intervals, and the widths of the first sidewall 4 and the second sidewall 5 at both ends are equal. For the sake of explanation, in the following description, the scintillator array with different widths between the first sidewall 4 and the second sidewall 5 will be referred to as the "first scintillator array 1a," and the other scintillator array will be referred to as the "second scintillator array 1b."

[0040] Figure 11 shows an example of an X-ray line sensor 10 in which a first X-ray line sensor array 10a and a second X-ray line sensor array 10b each include a first scintillator array 1a and a second scintillator array 1b. The example shown in Figure 11 is the "normal incidence type" X-ray line sensor 10 described above, and the first X-ray line sensor array 10a is configured to include a first scintillator array 1a provided on one end of the X-ray line sensor 10 and three second scintillator arrays 1b. Similarly, the second X-ray line sensor array 10b is configured to include a first scintillator array 1a provided on the other end of the X-ray line sensor 10 and three second scintillator arrays 1b. The first scintillator array 1a of the first X-ray line sensor array 10a and the first scintillator array 1a of the second X-ray line sensor array 10b are arranged in opposite directions so that they are offset by half a pixel. More specifically, as shown in Figure 11, the first scintillator array 1a included in the first X-ray line sensor array 10a and the first scintillator array 1a included in the second X-ray line sensor array 10b are positioned at the furthest diagonal points from each other, and each first scintillator array 1a is positioned in opposite directions. By positioning the first scintillator arrays 1a of each X-ray line sensor array 10a and the second X-ray line sensor array 10b at the furthest diagonal points from each other, even when multiple scintillator arrays are linked to form each X-ray line sensor array 10a, 10b, it is possible to construct an X-ray line sensor 10 that is shifted by half a pixel simply by aligning one end face and inverting one of the two X-ray line sensor arrays 10a, 10b.

[0041] In the example shown in Figure 11, each first scintillator array 1a is located on the left side of the first X-ray line sensor array 10a and on the right side of the second X-ray line sensor array 10b, but this relationship may be reversed. In other words, any configuration in which each first scintillator array 1a is located on the furthest diagonal is acceptable. Furthermore, the number of second scintillator arrays 1b included in the first X-ray line sensor array 10a and the second X-ray line sensor array 10b is not limited to three, but can be n or more, which is an integer greater than or equal to 1.

[0042] In the example shown in Figure 11, the substrate in the first scintillator array 1a is denoted as reference numeral 12a, and the substrate in the second scintillator array 1b is denoted as reference numeral 12b. Similarly, in the following explanation, the substrate of the first scintillator array 1a will be referred to as substrate 12a, and the substrate of the second scintillator array 1b will be referred to as substrate 12b.

[0043] With this configuration, even when multiple scintillator arrays are linked together, an X-ray line sensor 10 that allows for easy pixel shifting can be constructed. Furthermore, by including not only the first scintillator array 1a but also the second scintillator array 1b, the scintillator arrays can be linked without any gaps between the scintillator pixels 2 of one scintillator array 1 and the scintillator pixels 2 of the other scintillator array 1.

[0044] Furthermore, as shown in Figure 12, in the "horizontal incidence type" X-ray line sensor 10, similar to the example in Figure 11, the first X-ray line sensor row 10a and the second X-ray line sensor row 10b may each include a first scintillator array 1a and a second scintillator array 1b.

[0045] In the horizontal incidence type X-ray line sensor 10, as shown in Figure 12, the substrate 12b of the second scintillator array 1b of the first X-ray line sensor row 10a and the substrate 12a of the first scintillator array 1a are located on the opposite side from the second X-ray line sensor row 10b. Similarly, the substrate 12a of the first scintillator array 1a of the second X-ray line sensor row 10b and the substrate 12b of the second scintillator array 1b are located on the opposite side from the first X-ray line sensor row 10a. The other configurations are the same as in Figure 11, so a detailed explanation is omitted here.

[0046] Furthermore, when multiple scintillator arrays 1 are connected in each X-ray line sensor row 10a, 10b, the size of the substrate may be larger than that of the first scintillator array 1a or the second scintillator array 1b. In such cases, for example, in a "horizontal incidence type" X-ray line sensor 10, the substrates 12a and 12b may be configured in a staggered arrangement, as shown in Figure 13. Specifically, the substrate 12b of the second scintillator array 1b and the substrate 12a of the first scintillator array 1a of the first X-ray line sensor row 10a are arranged in a staggered pattern, flanking the second scintillator array 1b and the first scintillator array 1a of the first X-ray line sensor row 10a. Similarly, the substrate 12a of the first scintillator array 1a and the substrate 12b of the second scintillator array 1b of the second X-ray line sensor array 10b are arranged in a staggered pattern, flanking the first scintillator array 1a and the second scintillator array 1b of the second X-ray line sensor array 10b.

[0047] Furthermore, similar to the example described in Figure 11 above, the first scintillator array 1a of the first X-ray line sensor array 10a located at one end and the first scintillator array 1a of the second X-ray line sensor array 10b located at the other end are configured to be offset by half a pixel by being positioned in opposite directions. In other words, the first scintillator array 1a included in the first X-ray line sensor array 10a and the first scintillator array 1a included in the second X-ray line sensor array 10b are positioned at the furthest points on the diagonal, and each of the first scintillator arrays 1a is positioned in opposite directions.

[0048] With this configuration, even when the substrate is larger than the first scintillator array 1a or the second scintillator array 1b, pixel shifting can be easily performed in the X-ray line sensor 10 which includes multiple scintillator arrays.

[0049] [X-ray imaging system] Next, an X-ray imaging system 100 equipped with an X-ray line sensor 10 consisting of a scintillator array including the pixel shift described above will be explained. Figure 14 shows a schematic diagram of the X-ray imaging system 100. The X-ray imaging system 100 includes an X-ray source (not shown) for irradiating a subject with X-rays, an X-ray detector 20 for detecting X-rays, a signal processing circuit 30, and a control unit 50.

[0050] The X-ray source includes an X-ray tube and generates X-rays when a high voltage is applied, and irradiates the subject with the generated X-rays, for example, in a cone beam shape. The X-rays irradiated onto the subject are attenuated by passing through the subject and then incident on the X-ray detector 20. The energy range of the X-rays generated from the X-ray source may be within a predetermined range, for example, tens of keV to several MeV. The subject may be, for example, luggage, cargo, or industrial products.

[0051] The X-ray detector 20 includes the X-ray line sensor 10 and the collimator 40 described above. The X-ray line sensor 10 includes a first scintillator array 1a in which the widths of the first sidewall 4 and the second sidewall 5 are different, and is an X-ray line sensor 10 that can achieve high resolution and high sensitivity by image shifting. The X-ray line sensor 10 detects incident X-rays via the collimator 40. The collimator 40 introduces X-rays into the X-ray line sensor 10 while preventing unwanted X-rays such as scattered radiation from entering the X-ray line sensor 10.

[0052] Furthermore, a signal processing circuit 30 is connected to the substrate 12 of the X-ray line sensor 10 to process the measurement signal measured by the X-ray detector 20 and convert it into an image. This signal processing circuit 30 may be integrated with the substrate 12. Wiring connecting the photodetector 11 and the signal processing circuit 30 is formed on the substrate 12. The signal processing circuit 30 amplifies the measurement signal from the photodetector 11, converts the amplified analog signal into a digital signal, and generates an X-ray transmission image based on the converted digital signal. The number of scintillator pixels 2 in the X-ray line sensor 10 is, for example, "512", and in this embodiment, it is divided into four sections, and four signal processing circuits 30 process the divided measurement signals in parallel.

[0053] The X-ray transmission image output from the signal processing circuit 30 is then output to the control unit 50, and the generated X-ray transmission image is output to a display unit 60 such as a monitor. The control unit 50 may be a known computer that includes, for example, a control unit that performs various calculations, a storage unit having a storage medium, and an input / output interface (none of which are shown) that controls the input and output of data to and from the inside and outside of the control unit 50.

[0054] With the X-ray imaging system 100 configured in this way, the X-ray detector 20 and the subject are moved relative to each other to scan the subject with the X-ray detector 20, and the signal processing circuit 30 visualizes the measurement signals detected by the X-ray detector 20 to output an X-ray transmission image, thereby enabling non-destructive testing of the subject.

[0055] [Image processing method using an X-ray imaging system] Next, an image processing method for X-ray transmission images obtained using the above-described X-ray imaging system 100 will be explained. Figure 15 is a flowchart of an example of the image processing method. The image processing method comprises an image acquisition step S100 and an image generation step S120. The image acquisition step S100 includes a first image acquisition step S105 and a second image acquisition step S110.

[0056] In the image acquisition step S100, the control unit 50 acquires images captured by the first X-ray line sensor array 10a and the second X-ray line sensor array 10b. Specifically, in the same single imaging, the image acquisition step S100 performs the first image acquisition step S105 and the second image acquisition step S110.

[0057] In the first image acquisition step S105, the control unit 50 acquires images captured at predetermined timings. For example, the control unit 50 acquires an image captured by the first X-ray line sensor array 10a and an image captured by the second X-ray line sensor array 10b. This allows for the acquisition of two images based on the first X-ray line sensor array 10a and the second X-ray line sensor array 10b in the first image acquisition step S105.

[0058] In the second image acquisition step S110, the control unit 50 acquires an image captured at a timing corresponding to a position shifted by 1 / 2 pixel (i.e., half a pixel) relative to one pixel in the scanning direction. For example, if the X-ray line sensor 10 and the subject move relatively by 1 / 2 pixel per second, then one second after the predetermined timing in the first image acquisition step S105, the image captured by the first X-ray line sensor array 10a and the image captured by the second X-ray line sensor array 10b are acquired. As a result, in the second image acquisition step S110, two images based on the first X-ray line sensor array 10a and the second X-ray line sensor array 10b can be acquired.

[0059] Figure 16 is a diagram illustrating an example of an image processing method. In the first image acquisition step S105 described above, an image shown by a solid line is acquired by imaging the first X-ray line sensor array 10a, and an image shown by a dashed line is acquired by imaging the second X-ray line sensor array 10b. In the second image acquisition step S110, an image shown by a dashed-dotted line is acquired by imaging the first X-ray line sensor array 10a, and an image shown by a double-dotted-dotted line is acquired by imaging the second X-ray line sensor array 10b.

[0060] In the image generation step S120, the control unit 50 performs image generation processing based on four images: the two images acquired in the first image acquisition step S105 and the two images acquired in the second image acquisition step S110. In other words, as shown in the example in Figure 16, the control unit 50 extracts information from the shaded areas where each image overlaps and combines the images to generate a high-resolution image with four times the number of pixels. This makes it possible to generate high-resolution and high-sensitivity images.

[0061] Although each embodiment has been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these are also understood to naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0062] In the above-described embodiment, the side wall formation step S2 is not limited to a grooving step S20 in which grooves of different widths are cut into the scintillator block 6 to form the first side wall 4 and the second side wall 5, or to a adding step S21 in which the first side wall 4 and the second side wall 5 are added to the scintillator block 6 in a state where both ends are exposed. For example, it may be realized by a cutting step in which grooves of an arbitrary width are formed in advance at both ends of the scintillator block 6 by cutting, etc., and then the first side wall 4 and the second side wall 5 are formed by cutting to a predetermined width using a dicer, etc. Alternatively, it may be realized by a post-adding step in which, for a scintillator block 6 formed with equal widths at both ends, the first side wall 4 and the second side wall 5 are formed by thickening one side wall to have a different width, as can be assumed in the manufacturing direction of a normal scintillator array 1. The add-on step involves adding a reflective film to one side wall (the first side wall 4 in Figure 17), or forming a coating made of reflective material, as shown in Figure 17, thereby increasing the width of one side wall of the scintillator block 6, which is formed to have equal widths at both ends.

[0063] Furthermore, the aforementioned "pixel shifting" is a configuration in which the two scintillator arrays 1 have the same length, and the arrangement of the scintillator pixels 2 is shifted by half a pixel, and the intended pixel shift is achieved simply by aligning them by their outlines. Such "pixel shifting" is not limited to examples composed of two (i.e., two rows) of scintillator arrays 1, but can also be applied to examples composed of three or more n rows of scintillator arrays 1. For example, in the case of an example composed of three rows of scintillator arrays, the lengths of the three rows of scintillator arrays are all the same, and the pixels are shifted by 1 / 3 of a pixel each, thus constructing the three rows of scintillator arrays. Even in this case, the intended pixel shift can be achieved by aligning them by their outlines.

[0064] This specification contains at least the following information. Note that the components etc. in parentheses indicate those corresponding to the embodiments described above, but are not limited thereto.

[0065] (1) A scintillator array (scintillator array 1) consisting of multiple scintillator pixels (scintillator pixels 2) that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first side walls (first side wall 4) and the second side walls (second side wall 5) at both ends are different. When two of the aforementioned scintillator arrays are arranged in opposite directions and overlapping each other, the scintillator pixels of one scintillator array and the scintillator pixels of the other scintillator array are configured to be offset by half a pixel. Scintillator array.

[0066] According to (1), scintillator arrays are arranged in a way that overlaps them and in opposite directions, with the first and second sidewalls at both ends having different widths. Therefore, when two scintillator arrays are arranged in an overlapping configuration, pixel shifting can be easily achieved by aligning the external shapes of the two scintillator arrays. In other words, a scintillator array capable of easily acquiring high-resolution and high-sensitivity images can be constructed.

[0067] (2) A scintillator array (scintillator array 1) consisting of a plurality of scintillator pixels (scintillator pixels 2) that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first side walls (first side wall 4) and the second side walls (second side wall 5) at both ends are different. When the width of the first side wall is W1, the width of the second side wall is W2 which is smaller than the width of the first side wall, the width of the partition wall is W3, and the width of the scintillator pixel is T, W1 + T / 2 = W2 + T + W3 / 2 It is configured to satisfy, Scintillator array.

[0068] According to (2), pixel shifting can be easily achieved by generating a scintillator array that satisfies this relationship.

[0069] (3) The scintillator array described in (1), A photodetector (photodetector 11) for detecting scintillation light emitted by the scintillator array, The system comprises a substrate (substrate 12) on which the aforementioned photodetector is mounted, X-ray line sensor (X-ray line sensor 10).

[0070] According to (3), an X-ray line sensor capable of easily implementing pixel shifting can be constructed.

[0071] (4) The X-ray line sensor described in (3), It comprises a first X-ray line sensor array (first X-ray line sensor array 10a) and a second X-ray line sensor array (second X-ray line sensor array 10b) arranged in parallel, The first X-ray line sensor array and the second X-ray line sensor array each include a first scintillator array (first scintillator array 1a) composed of the scintillator array, The first scintillator array of the first X-ray line sensor array and the first scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

[0072] According to (4), image shifting can be easily achieved in an X-ray line sensor including a row of X-ray line sensors composed of a first scintillator array.

[0073] (5) The X-ray line sensor described in (4), The first X-ray line sensor array includes a plurality of the first scintillator arrays, The second X-ray line sensor array includes a plurality of the first scintillator arrays, The plurality of first scintillator arrays of the first X-ray line sensor row and the plurality of first scintillator arrays of the second X-ray line sensor row are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

[0074] According to (5), even if each X-ray line sensor row includes multiple first scintillator arrays, pixel shifting can be easily achieved by arranging the first scintillator arrays of each X-ray line sensor row in opposite directions to one another.

[0075] (6) The X-ray line sensor described in (4), The first X-ray line sensor array and the second X-ray line sensor array each include a second scintillator array (second scintillator array 1b) which is composed of another scintillator array configured such that the widths of the first and second side walls at both ends are equal, with the scintillator pixels arranged linearly by partition walls at equal intervals, respectively. The first X-ray line sensor array includes the first scintillator array provided on one end of the X-ray line sensor, and n (where n is an integer of 1 or more) second scintillator arrays, The second X-ray line sensor array includes the n second scintillator arrays and the first scintillator array provided on the other end of the X-ray line sensor, The first scintillator array of the first X-ray line sensor array and the first scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

[0076] According to (6), the first scintillator array at one end of the first X-ray line sensor row and the first scintillator array at the other end of the second X-ray line sensor row are arranged in opposite directions and offset by half a pixel, so that even an X-ray line sensor including a first scintillator array and a second scintillator array can be easily shifted.

[0077] (7) An X-ray line sensor as described in (6), The substrate of the second scintillator array of the first X-ray line sensor array and the substrate of the first scintillator array are provided on the side opposite to the second X-ray line sensor array. The substrate of the first scintillator array of the second X-ray line sensor array and the substrate of the second scintillator array are provided on the opposite side from the first X-ray line sensor array. X-ray line sensor.

[0078] According to (7), in addition to the X-ray line sensors described in (6), positional shifting can also be easily achieved in X-ray line sensors in which the substrate of the first X-ray line sensor array is provided on the opposite side from the second X-ray line sensor array, and the substrate of the second X-ray line sensor array is provided on the opposite side from the first X-ray line sensor array.

[0079] (8) The X-ray line sensor described in (6), The substrate of the second scintillator array of the first X-ray line sensor array and the substrate of the first scintillator array are arranged in a staggered pattern, sandwiching the second scintillator array and the first scintillator array of the first X-ray line sensor array. The substrates of the first scintillator array and the second scintillator array of the second X-ray line sensor array are arranged in a staggered pattern, flanking the first and second scintillator arrays of the second X-ray line sensor array. X-ray line sensor.

[0080] According to (8), even if the substrate is larger than the first or second scintillator array, positional shifting can be easily achieved by arranging the substrates in a staggered pattern.

[0081] (9) The X-ray line sensor described in (5), It is further equipped with a control unit (control unit 50), The control unit is When multiple first scintillator arrays are linked together, virtual data (virtual data 2a) is generated for the gaps between the scintillator pixels of the first scintillator array. The aforementioned virtual data is Using the data of the scintillator pixels adjacent to each other across the aforementioned gap, X-ray line sensor.

[0082] According to (9), by using adjacent pixel data, highly accurate virtual data can be generated. In other words, since data usually exists on both sides of a pitch jump, by using that data, virtual data can be generated as if data had existed there, thereby improving the accuracy of the data.

[0083] (10) An X-ray line sensor (X-ray line sensor 10) comprising a scintillator array (scintillator array 1) composed of a plurality of scintillator pixels (scintillator pixels 2), The X-ray line sensor comprises a first X-ray line sensor array (first X-ray line sensor array 10a) and a second X-ray line sensor array (second X-ray line sensor array 10b) arranged in parallel. The scintillator array of the first X-ray line sensor array and the scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel. X-ray line sensor.

[0084] According to (10), the scintillator array of the first X-ray line sensor row and the scintillator array of the second X-ray line sensor row are configured to be offset by half a pixel, thereby enabling higher resolution and higher sensitivity in the X-ray line sensor.

[0085] (11) The X-ray line sensor described in (3) or (10), A signal processing circuit (signal processing circuit 30) processes the measurement signal measured by the X-ray line sensor and converts it into an image, Equipped with, X-ray imaging system (X-ray imaging system 100).

[0086] According to (11), an X-ray transmission image can be generated based on an image acquired by an X-ray line sensor configured to perform image shifting.

[0087] (12) A method for manufacturing a scintillator array as described in (2), A partition wall forming step (partition wall forming step S1) is performed to form partition walls at equal intervals relative to the scintillator block (scintillator block 6), A side wall forming step (side wall forming step S2) is performed to form a first side wall and a second side wall with different side wall widths relative to the scintillator block, Equipped with, A method for manufacturing scintillator arrays.

[0088] According to (12), a scintillator array can be manufactured in which the sidewall widths of the first sidewall and the second sidewall are different.

[0089] (13) A method for manufacturing a scintillator array as described in (12), The side wall forming step is, A grooving step (grooving step S20) is performed to form the first side wall and the second side wall by cutting grooves of different widths into the scintillator block. The first side wall and the second side wall are added to the scintillator block, which has partition walls formed at equal intervals and both ends exposed (addition step S21). A cutting step in which a first side wall and a second side wall are formed by cutting both ends of the scintillator block, which has both ends formed to an arbitrary width, so that they have different widths, A post-installation step of thickening one side wall of the scintillator block, which has both ends formed to be of equal width, Including any of the following: A method for manufacturing scintillator arrays.

[0090] According to (13), for example, a first side wall and a second side wall with different side wall widths can be easily formed by a grooving step using a dicer or the like. In addition, the first side wall and the second side wall can be formed with high precision by an application step such as attaching a reflective film or forming a coating made of a reflective material. Furthermore, for a scintillator block with both ends formed to an arbitrary width, the first side wall and the second side wall can be formed by a cutting step in which both ends are cut to have different widths. Furthermore, for a scintillator block with both ends formed to an equal width, the first side wall and the second side wall can be formed by an add-on step in which one side wall is thickened to have a different width.

[0091] (14) An image processing method using the X-ray imaging system described in (11), The first image acquisition step (first image acquisition step S105) involves acquiring an image captured at a predetermined timing, A second image acquisition step (second image acquisition step S110) acquires an image captured at a timing corresponding to a position shifted by 1 / 2 pixel for each pixel in the scanning direction, The system comprises the first image acquisition step, the second image acquisition step, and an image generation step (image generation step S120) which performs image generation processing based on the images acquired in the first image acquisition step and the second image acquisition step. Image processing method using an X-ray imaging system.

[0092] According to (14), in the first image acquisition step, two images configured to perform pixel shifting can be acquired, and in the second image acquisition step, two images can be acquired at positions shifted by 1 / 2 pixel. Then, by combining the acquired images in this way, an image can be generated, making it possible to produce high-resolution, high-sensitivity images. [Explanation of Symbols]

[0093] 1. Scintillator array 1a First scintillator array 1b Second scintillator array 2 scintillator pixels 2a Virtual data 4. First side wall 5. Second side wall 6. Scintillator block 10 X-ray line sensors 10a First X-ray line sensor array 10b Second X-ray line sensor array 11. Photodetector 12 circuit boards 30 Signal Processing Circuits 50 control units 100 X-ray imaging system S1 Partition wall formation step S2 Side wall forming step S21 Granting Step S105 First image acquisition step S110 Second image acquisition step S120 Image generation step

Claims

1. A scintillator array composed of multiple scintillator pixels that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first and second side walls at both ends are different. When two of the aforementioned scintillator arrays are arranged in opposite directions and overlapping each other, the scintillator pixels of one scintillator array and the scintillator pixels of the other scintillator array are configured to be offset by half a pixel. Scintillator array.

2. A scintillator array composed of multiple scintillator pixels that convert X-rays into light, Multiple scintillator pixels are arranged in a straight line by partitions at equal intervals, and the widths of the first and second side walls at both ends are different. When the width of the first side wall is W1, the width of the second side wall is W2 which is smaller than the width of the first side wall, the width of the partition wall is W3, and the width of the scintillator pixel is T, W1+T / 2=W2+T+W3 / 2 It is configured to satisfy, Scintillator array.

3. The scintillator array according to claim 1, A photodetector for detecting scintillation light emitted by the scintillator array, A substrate on which the aforementioned photodetector is mounted, X-ray line sensor.

4. An X-ray line sensor according to claim 3, It comprises a first X-ray line sensor array and a second X-ray line sensor array arranged in parallel, The first X-ray line sensor array and the second X-ray line sensor array each include a first scintillator array composed of the scintillator array, The first scintillator array of the first X-ray line sensor array and the first scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

5. An X-ray line sensor according to claim 4, The first X-ray line sensor array includes a plurality of the first scintillator arrays, The second X-ray line sensor array includes a plurality of the first scintillator arrays, The plurality of first scintillator arrays in the first X-ray line sensor array and the plurality of first scintillator arrays in the second X-ray line sensor array are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

6. An X-ray line sensor according to claim 4, The first X-ray line sensor array and the second X-ray line sensor array each include a second scintillator array, which is composed of another scintillator array configured such that a plurality of the scintillator pixels are arranged linearly by partitions at equal intervals, and the widths of the first and second side walls at both ends are equal. The first X-ray line sensor array includes the first scintillator array provided on one end of the X-ray line sensor, and n (where n is an integer of 1 or more) second scintillator arrays, The second X-ray line sensor array includes the n second scintillator arrays and the first scintillator array provided on the other end of the X-ray line sensor, The first scintillator array of the first X-ray line sensor array and the first scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel by being arranged in opposite directions. X-ray line sensor.

7. An X-ray line sensor according to claim 6, The substrate of the second scintillator array of the first X-ray line sensor array and the substrate of the first scintillator array are provided on the opposite side from the second X-ray line sensor array. The substrate of the first scintillator array of the second X-ray line sensor array and the substrate of the second scintillator array are provided on the opposite side from the first X-ray line sensor array. X-ray line sensor.

8. An X-ray line sensor according to claim 6, The substrate of the second scintillator array of the first X-ray line sensor array and the substrate of the first scintillator array are arranged in a staggered pattern, sandwiching the second scintillator array and the first scintillator array of the first X-ray line sensor array. The substrate of the first scintillator array and the substrate of the second scintillator array of the second X-ray line sensor array are arranged in a staggered pattern, flanking the first scintillator array and the second scintillator array of the second X-ray line sensor array. X-ray line sensor.

9. An X-ray line sensor according to claim 5, It is further equipped with a control unit, The control unit is When multiple first scintillator arrays are linked together, virtual data is generated for the gaps between the scintillator pixels of the first scintillator array. The aforementioned virtual data is Using the data of the scintillator pixels adjacent to each other across the aforementioned gap, X-ray line sensor.

10. An X-ray line sensor comprising a scintillator array composed of multiple scintillator pixels, The aforementioned X-ray line sensor comprises a first X-ray line sensor array and a second X-ray line sensor array arranged in parallel. The scintillator array of the first X-ray line sensor array and the scintillator array of the second X-ray line sensor array are configured to be offset by half a pixel. X-ray line sensor.

11. An X-ray line sensor according to claim 3 or 10, A signal processing circuit that processes the measurement signal measured by the X-ray line sensor and converts it into an image, Equipped with, X-ray imaging system.

12. A method for manufacturing a scintillator array according to claim 2, A partition wall forming step in which partition walls are formed at equal intervals relative to the scintillator block, A side wall forming step in which a first side wall and a second side wall with different side wall widths are formed relative to the scintillator block, Equipped with, A method for manufacturing scintillator arrays.

13. A method for manufacturing a scintillator array according to claim 12, The side wall forming step is, Grooving step to form the first side wall and the second side wall by cutting grooves of different widths into the scintillator block, A step of adding the first side wall and the second side wall to the scintillator block, which has partition walls formed at equal intervals and both ends exposed. A cutting step in which a first side wall and a second side wall are formed by cutting both ends of the scintillator block, which has both ends formed to an arbitrary width, so that they have different widths, A post-installation step of thickening one side wall of the scintillator block, which has both ends formed to be of equal width, Including any of the following: A method for manufacturing scintillator arrays.

14. An image processing method using the X-ray imaging system described in claim 11, A first image acquisition step involves acquiring an image captured at a predetermined timing, A second image acquisition step involves acquiring an image captured at a timing corresponding to a position shifted by 1 / 2 pixel relative to one pixel in the scanning direction, The system comprises: a first image acquisition step, a second image acquisition step, and an image generation step that performs image generation processing based on the images acquired in the first image acquisition step and the second image acquisition step. Image processing method using an X-ray imaging system.

Images