X-ray inspection equipment

Abstract

An X-ray inspection device that inspects an object by imaging using X-rays, and comprises: an inspection time condition acquisition unit that accepts input of conditions related to the inspection time; an imaging condition storage unit that stores an imaging mode composed of a plurality of imaging parameters that determine the imaging conditions, the imaging mode being associated with the conditions related to the inspection time; a determination image acquisition unit that acquires a determination image for determining image quality from an X-ray image, the X-ray image being captured based on the imaging mode associated with the input conditions related to the inspection time; an image quality measurement unit that measures the image quality of the determination image; and an image quality determination unit that determines whether the measured image quality of the determination image satisfies a determination criterion, the image quality determination unit determining as the imaging condition the imaging parameters included in the imaging mode corresponding to the X-ray image when the determination image determined to satisfy the determination criterion is acquired.

Description

Technical Field

[0001] The present invention relates to an X-ray inspection device using X-ray transmission or CT (Computer Tomography). Background Art

[0002] Conventionally, in X-ray transmission or CT X-ray inspection devices, there are many setting items for imaging conditions, which is time-consuming and laborious. In addition, it is difficult for users with little experience to determine the best condition settings.

[0003] Therefore, regarding the setting of imaging conditions in an X-ray CT apparatus, a technique such as that described in Patent Document 1 has been proposed. Here, a user simply inputs two-dimensional indices related to image quality, such as the material of the inspection object, such as resin, contrast, and field angle, through an imaging condition setting screen on a monitor. Then, based on the information input by the user through the imaging condition setting screen, a preset imaging condition is selected, and a preview image corresponding to the selected imaging condition is displayed on the monitor.

[0004] Patent Document 1: Japanese Patent No. 6519663

[0005] However, in the above technology, when the user inputs information related to the imaging conditions, the inspection time (tact time) is not mentioned. In the X-ray inspection device, the inspection time is an important factor. This is because if the production line is configured to ship products after the inspection process based on the X-ray inspection device, the number of shipments per day is limited by the number of inspections that can be performed per day based on the X-ray inspection device. Summary of the invention

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an X-ray inspection apparatus capable of easily setting imaging conditions that can obtain a good image quality within an appropriate inspection time.

[0007] The present invention for solving the above-mentioned problems is an X-ray inspection device that uses X-rays to perform imaging, thereby inspecting an object, and the X-ray inspection device is characterized in that it has: an inspection time condition acquisition unit that accepts input of conditions related to the inspection time; an imaging condition storage unit that stores an imaging mode composed of a plurality of imaging parameters that determine the imaging conditions, the imaging mode being associated with the conditions related to the inspection time; a judgment image acquisition unit that acquires a judgment image for judging image quality from an X-ray image, the X-ray image being captured based on the imaging mode associated with the input conditions related to the inspection time; an image quality measurement unit that measures the image quality of the judgment image; and an image quality judgment unit that determines whether the measured image quality of the judgment image satisfies a judgment criterion, the image quality judgment unit determining as an imaging condition the imaging parameters included in the imaging mode corresponding to the X-ray image when the judgment image determined to satisfy the judgment criterion is generated.

[0008] According to the present invention, the input of the condition related to the inspection time is accepted by the inspection time condition acquisition unit. Then, the judgment image is acquired from the X-ray image captured based on the imaging mode associated with the input condition related to the inspection time, and when the image quality measured by the judgment image satisfies the judgment criterion, the imaging parameters included in the imaging mode corresponding to the X-ray image when the judgment image is acquired are determined as the imaging conditions. Therefore, according to the present invention, an X-ray inspection device can be provided, which can input the condition related to the inspection time, so that the imaging conditions that can not only obtain an image with good image quality but also make the inspection time appropriate can be easily set.

[0009] Furthermore, in the present invention, the condition related to the inspection time may include whether the inspection time changes or does not change.

[0010] The user is prompted with a prescribed inspection time as a reference, such as an inspection time corresponding to a preset imaging condition, and can choose whether to set the imaging condition within a range in which the inspection time varies from such a prescribed inspection time, or within a range in which the inspection time does not vary. In this way, by inputting an inspection time variation or an inspection time non-variation as a condition related to the inspection time, it is possible to easily set imaging conditions that satisfy the requirements of a case where the inspection time is emphasized and a case where the image quality is emphasized, respectively. Here, it is also possible that, in the case in which the inspection time does not vary, variations within a range including a time below the prescribed inspection time are permitted, that is, the prescribed inspection time is set as an upper limit, and variations not exceeding the upper limit are permitted. It is also possible that, in the case in which the inspection time varies, both a case in which the time becomes longer than the prescribed inspection time and a case in which the time becomes shorter than the prescribed inspection time are permitted.

[0011] In addition, in the present invention, the condition related to the inspection time may be determined as the imaging condition by the imaging parameters included in the imaging mode associated with the shortest inspection time among the inspection times associated with the imaging mode corresponding to the X-ray image when the judgment image is judged to meet the judgment criteria.

[0012] In this way, among the imaging conditions that satisfy the determination criteria, the imaging conditions that minimize the inspection time can be easily set.

[0013] In the present invention, the condition related to the inspection time may determine a time or a range as the inspection time.

[0014] In this way, the inspection time becomes a specific time or a specific time range, and the imaging conditions that can achieve good image quality can be easily set.

[0015] According to the present invention, it is possible to provide an X-ray inspection apparatus capable of easily setting imaging conditions that can obtain a good image quality within an appropriate inspection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a functional block diagram of the X-ray inspection device according to the first embodiment of the present invention.

[0017] Figure 2 This is a flowchart illustrating the steps of automatic setting processing of imaging conditions of the X-ray inspection apparatus according to the first embodiment of the present invention.

[0018] Figure 3 This is a diagram illustrating an external requirement UI according to the first embodiment of the present invention.

[0019] Figure 4 This is a diagram illustrating a UI according to the first embodiment of the present invention.

[0020] Figure 5 This is a graph showing the relationship between the number of projections and image quality.

[0021] Figure 6 It is a graph showing the relationship between the number of projections and image quality.

[0022] Description of symbols

[0023] 1: X-ray inspection device

[0024] 114: Imaging condition storage unit

[0025] 124: Determination image acquisition unit

[0026] 125: Image quality measurement department

[0027] 126: Image quality determination unit

[0028] 131: External Requirements UI DETAILED DESCRIPTION

[0029] [Application Examples]

[0030] Next, application examples of the present invention will be described with reference to the accompanying drawings.

[0031] First, the setting of imaging conditions in an X-ray inspection apparatus using CT (also referred to as an "X-ray CT apparatus") which is the background of the present invention will be described.

[0032] The X-ray CT apparatus uses a plurality of (e.g., about 15 to 500) projection data to perform reconstruction processing and obtain a CT image. When performing CT imaging using an X-ray CT apparatus, it is impossible to confirm whether the reconstructed image is the best image until the CT imaging and reconstruction processing are completed. Therefore, when the CT imaging conditions are inappropriate, the CT imaging and reconstruction processing must be repeated from the beginning. Even if the CT imaging is performed again, if the reconstructed image after the re-shooting is not confirmed, it is unknown whether the reset CT imaging conditions are optimal. In some cases, CT imaging must be repeated multiple times until the best reconstructed image is obtained.

[0033] In such an X-ray CT apparatus, various materials and structures are used as imaging objects, and the resolution (spatial resolution, concentration resolution) and imaging time required for the image are also various. Therefore, the imaging conditions have a high degree of freedom, and it is necessary to set the imaging conditions such as the angle, tube voltage, tube current, exposure time, number of projections, and resolution recorded in the left column of Table 1 for each object.

[0034]

Table 1

[0035]

[0036] The difference in image quality when the number of projections in the above-mentioned imaging parameters is changed is shown. However, the tube voltage, tube current, and exposure time are not changed and are set to have the same contrast. Figure 5 (A)~ Figure 5 (H) represents captured images when the number of projections is set to 1, 2, 4, 8, 16, 32, 64, and 128, respectively. Figure 6 Graph showing the relationship between the number of projections and image quality. The image quality value on the vertical axis represents a value evaluating the ratio of the signal level to the noise level in percentage. Figure 5 (A)~ Figure 5 As can be seen from (D), the image quality improves as the number of projections increases, but according to Figure 5 (E)~ Figure 5 As can be seen from (H), if the number of projections exceeds 16, the image quality will not improve much even if the number of projections increases. Figure 6 It can be clearly seen that the image quality increases exponentially with the number of projections, but when the number of projections increases to a certain extent, the image quality tends to converge. On the other hand, the tact time is also extended in proportion to the increase in the number of projections.

[0037] As described above, in an X-ray CT apparatus, the examination time (takt time) may be prolonged depending on the imaging conditions. Therefore, in the present invention, the imaging conditions are set so as to achieve the best image quality and the examination time in a well-balanced manner.

[0038] Figure 1 is a functional block diagram of an X-ray inspection device 1 to which the present invention is applied, Figure 2 This is a flowchart of the automatic setting process of imaging conditions in the X-ray inspection apparatus 1 .

[0039] The X-ray inspection device includes an external element UI 131. Figure 3 As shown, the external requirement UI 131 is configured to be able to select whether the inspection time is unchanged or changed for input. When the inspection time is unchanged (step S1), the imaging mode in which the inspection time is unchanged is set in the setting conditions stored in the imaging condition storage unit 114 in sequence (step S3). Then, the three-dimensional data of the inspection object is reconstructed using the X-ray images captured according to each imaging condition (steps S4 and S5). The image quality of the judgment image obtained from the three-dimensional data is measured (steps S6 and S7), and it is determined whether the judgment criterion is met (step S8). Then, the imaging condition corresponding to the judgment image determined to meet the judgment criterion is determined as the imaging condition used in the inspection (step S10).

[0040] As described above, according to the present invention, it is possible to easily set imaging conditions that can obtain the best image quality within an appropriate examination time.

[0041] [Example 1]

[0042] Hereinafter, an X-ray inspection device 1 according to Embodiment 1 of the present invention will be described in more detail using the drawings. However, the configuration of the device described in this embodiment should be appropriately changed according to various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.

[0043] <Device Structure>

[0044] Figure 1 1 is a functional block diagram showing a schematic configuration of the X-ray inspection apparatus 1. Here, an X-ray inspection apparatus using a CT image of X-rays will be described.

[0045] The X-ray inspection apparatus 1 is an apparatus that acquires three-dimensional data by imaging an inspection object from a plurality of imaging positions, and mainly includes an imaging unit 11, a computing unit 12, a UI unit 13, and a bus 14. The bus 14 is a transmission path that connects the various units to transmit and receive data.

[0046] The imaging unit 11 includes an X-ray generator 111 , an X-ray detector 112 , a stage 113 , and an imaging condition storage unit 114 .

[0047] The X-ray generator 111 is a device that irradiates an inspection object with X-rays.

[0048] The X-ray detector 112 is a two-dimensional X-ray detector that detects X-rays output from the X-ray generator 111 and transmitted through the inspection object to form an image, and can use, for example, an II (Image Intensifier) ​​tube or an FPD (Flat Panel Detector).

[0049] The stage 113 is a mechanism for changing the relative positions of all or part of the X-ray generator 111, the X-ray detector 112, and the inspection object in the X, Y, and Z directions to image the inspection object from a plurality of imaging positions.

[0050] The imaging condition storage unit 114 is a predetermined area of ​​a memory (for example, composed of an auxiliary storage unit described later), and stores imaging conditions in association with examination times when examinations are performed under the imaging conditions.

[0051] The operation unit 12 includes a three-dimensional data generation unit 121, a Z position acquisition unit 122, an XY position acquisition unit 123, a judgment image acquisition unit 124, an image quality measurement unit 125, an image quality judgment unit 126, and an XYZ position information storage unit 127. The operation unit 12 is a device for performing various operations such as calculation and inspection processing of X-ray CT, and can be composed of a logic circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). It is also possible to use a common general-purpose operation device called a CPU (central processing unit), a main storage unit, and an auxiliary storage unit. As the main storage unit, a memory such as a RAM can be used. The auxiliary storage unit can use a ROM, a HDD, an SSD, etc.

[0052] The three-dimensional data generator 121 is a functional unit that generates three-dimensional data based on a plurality of X-ray transmission images captured by the X-ray detector 112 .

[0053] The Z position acquisition unit 122 is a functional unit that acquires the Z position of the three-dimensional data generated by the three-dimensional data generation unit 121 .

[0054] The XY position acquisition unit 123 is a functional unit that acquires the XY position of the region acquired by the Z position acquisition unit 122 in the three-dimensional data generated by the three-dimensional data generation unit 121 .

[0055] The determination image acquisition unit 124 is a functional unit that acquires a determination image for determining image quality for an image of a corresponding region of the three-dimensional data generated by the three-dimensional data generation unit 121 based on the XYZ position information acquired from the XYZ position information storage unit 127 .

[0056] The image quality measuring unit 125 is a functional unit that measures the image quality of the determination image acquired by the determination image acquiring unit 124 .

[0057] The image quality determination unit 126 is a functional unit that determines whether the image quality of the determination image acquired by the determination image acquisition unit 124 satisfies a determination criterion based on the measurement result by the image quality measurement unit 125 .

[0058] The XYZ position information storage unit 127 is a predetermined area of ​​a memory (eg, composed of an auxiliary storage unit) and stores XYZ position information in three-dimensional data of an inspection object for determining image quality via the UI unit 13 .

[0059] The UI unit 13 includes an external requirement UI 131, an XYZ position UI 132, an inspection target part (area) position UI 133, and a result display UI 134. The UI unit 13 is an interface for transmitting and receiving various information between the user and the X-ray inspection apparatus, and can be displayed on a touch panel display that also serves as an input and output unit, or on an output unit such as an independently constructed display, and accepts inputs from input units such as a mouse and a keyboard.

[0060] The external requirement UI 131 is a user interface for accepting input of conditions related to the inspection time as external requirements, for example, Figure 3 Here, the external requirement UI 131 corresponds to the inspection time condition acquisition unit of the present invention.

[0061] The XYZ position UI 132 is a user interface for inputting the XYZ position of a region used for image quality determination in three-dimensional data of the inspection object.

[0062] The inspection target component (region) position UI 133 is a user interface for inputting the position of the inspection target component (inspection target component) or the inspection target region (inspection target region) in the inspection target object. Hereinafter, the inspection target component and / or the inspection target region are simply referred to as "inspection target component (region)".

[0063] The result display UI 134 is a user interface that displays the result of the automatic setting process of the imaging conditions.

[0064] <Automatic setting of image capturing conditions>

[0065] Next, refer to Figure 2 , the steps for automatically setting the camera conditions are explained.

[0066] Before the automatic setting process of the imaging condition, a window is set for each of the inspection target components (regions) included in the captured image of the inspection target object. When setting the window, standard imaging conditions are also preset.

[0067] Then, any one of the inspection target parts (areas) for which the window is set is selected and the automatic setting button is pressed to start the automatic setting process of the imaging conditions. At this time, the location for measuring the image quality described later may also be determined.

[0068] First, the external requirement UI 131 is displayed on the display to accept the user's input (step S1). Figure 3 The dialog box shown. Here, in addition to the display of "Automatic Adjustment" that guides the automatic setting of the imaging conditions, two radio buttons for selecting either "Inspection time does not change" or "Inspection time changes" are also displayed. When "Inspection time does not change" is selected, external requirements (adjustment parameters of imaging conditions) such as inspection time does not change are set, and when "Inspection time changes" is selected, external requirements that allow inspection time to change are set. And at this time, the inspection time (for example, 6.0 seconds) based on the preset standard imaging conditions is displayed in the dialog box or outside. The inspection time displayed here can be the time for the entire inspection area or the inspection time only for the inspection object part. In addition, an "OK" button and a "Cancel" button are displayed in the dialog box. When the "OK" button is pressed, the user's selection of the radio button is determined as input. When the "Cancel" button is pressed, the user's selection of the radio button is canceled and the radio button selection is made again.

[0069] Next, a location for measuring image quality in the three-dimensional data of the inspection object is set (step S2). This step may be omitted if it is determined when the window is set or is set in a subsequent step.

[0070] Next, based on the external conditions set in step S1, an imaging mode of X-ray imaging parameters used in the automatic setting process of imaging conditions is set (step S3).

[0071] Table 2 shows examples of X-ray imaging parameters constituting the imaging mode.

[0072]

Table 2

[0073]

[0074] Here, as the X-ray imaging parameters, angle, tube voltage, tube current, exposure time, number of projections, and resolution are exemplified, but the X-ray imaging parameters used for automatic setting of imaging conditions are not limited thereto.

[0075] Among these X-ray imaging parameters, the ones that affect the takt time are the angle, exposure time, number of projections, and resolution, while the ones that do not affect the takt time are the tube voltage and tube current. Among them, even if the resolution is changed, since only the resolution change has no effect on the image quality, the resolution is not used for the automatic setting of imaging conditions. Here, the takt time is the time required to inspect the inspection object under the set imaging conditions (inspection time).

[0076] In step S1 , when “no change in examination time” is selected as the external condition, an imaging mode for automatically setting imaging conditions is set using tube voltage and tube current as X-ray imaging parameters.

[0077] Furthermore, in step S1, when "examination time variation" is selected as the external condition, an imaging mode for automatically setting imaging conditions is set using angle, tube voltage, tube current, exposure time, and number of projections as X-ray imaging parameters.

[0078] The imaging mode for automatic setting of imaging conditions is not limited thereto.

[0079] Next, the processing of steps S4 to S9 described later is repeated for all imaging modes (loop L1). At this time, when imaging is repeated for all imaging modes, the priority order in which the multiple imaging parameters included in the imaging mode are changed can be appropriately set. However, if "examination time variation" is selected in step S1, the values ​​can be changed in the order of angle, tube voltage, and tube current.

[0080] For one imaging mode, first, the X-ray generator 111 and the X-ray detector 112 are controlled to perform X-ray imaging of the inspection object (step S4).

[0081] Next, the three-dimensional data generating unit 121 generates three-dimensional data based on the X-ray image captured in step S4 (step S5 ).

[0082] Next, the determination image acquisition unit 124 acquires the XYZ position for determining the slice for measuring the image quality set in step S2 from the XYZ position information storage unit 127, and extracts the image for determining the image quality corresponding to the XYZ position (step S6). Even if the XYZ position for determining the location for measuring the image quality is not set in step S2, it may be set in this step.

[0083] Next, the image quality measuring unit 125 measures the image quality (step S7). The image quality measuring method is not particularly limited, and for example, appropriate methods such as SN ratio, mean square error (MSE), detail variance, and background variance may be used. In measuring the image quality, the window set before the automatic setting process may be used.

[0084] Next, the image quality determination unit 126 determines whether the image quality satisfies an internally set determination criterion based on the image quality measurement result in step S7 (step S8 ).

[0085] In step S8, if the image quality satisfies the determination criterion, the process proceeds to step S10. In step S10, the image quality determination unit 126 determines the imaging condition corresponding to the imaging determined to satisfy the criterion in step S8 as the imaging condition to be set. The imaging condition determined in step S10 and the inspection time under the imaging condition are displayed on the display in the form of a result display UI 134 such as a dialog box (step S11), and the imaging condition and inspection time at this time are set, and the automatic setting process ends.

[0086] In step S8, when the image quality does not satisfy the standard, the process proceeds to the next imaging mode (step S9), and specifically, the process from X-ray imaging (step S4) onwards is repeated.

[0087] If the image quality does not meet the standard in step S8 for all the imaging modes, the image quality determination unit 126 Figure 4 A dialog box as shown is displayed on the display to report the situation to the user (step S12). Here, an "OK" button is displayed together with a message "Although the benchmark is not met, the imaging condition with the best image quality is set." When the user presses the "OK" button, the imaging condition with the best image quality is determined as the imaging condition to be set (step S13), and the same processing as step S11 is performed. If the user does not press the "OK" button and a specified time has passed, the automatic setting process ends.

[0088] When a plurality of inspection target components (regions) are included in the field of view, imaging conditions are automatically set similarly for other inspection target components (regions).

[0089] As described above, in the X-ray inspection apparatus 1 of the present embodiment, it is possible to easily set imaging conditions that can obtain the best image quality within an appropriate inspection time.

[0090] [Modifications]

[0091] In the above-mentioned first embodiment, as the external requirement UI 131, whether the examination time is changed or not can be selected and inputted with respect to the examination time. The conditions related to the examination time that can be inputted through the external requirement UI 131 are not limited thereto. For example, in the case where there are multiple imaging conditions that satisfy the determination criteria, the imaging condition with the shortest examination time can also be determined as the imaging condition for the examination. In addition, a condition that makes the examination time a specific time or a specific time range can also be inputted. In this way, it is possible to easily set imaging conditions that can obtain good image quality within the examination time that meets the user's requirements.

[0092] In addition, in order to be able to compare the structural elements of the present invention with the structures of the embodiments, the structural elements of the present invention are described using reference numerals.

[0093] <Invention 1>

[0094] An X-ray inspection device (1) is provided for inspecting an object by imaging using X-rays, wherein the X-ray inspection device (1) is characterized in that:

[0095] An inspection time condition acquisition unit (131) which accepts input of conditions related to inspection time;

[0096] An imaging condition storage unit (114) storing an imaging mode composed of a plurality of imaging parameters for determining imaging conditions, wherein the imaging mode is associated with the condition related to the inspection time;

[0097] a determination image acquisition unit (124) for acquiring a determination image for determining image quality from an X-ray image captured based on the imaging mode associated with the input condition related to the inspection time;

[0098] an image quality measuring unit (125) for measuring the image quality of the determination image; and

[0099] an image quality determination unit (126) for determining whether the measured image quality of the determination image satisfies a determination criterion,

[0100] The image quality determination unit (126) determines the imaging parameters included in the imaging mode corresponding to the X-ray image when the determination image determined to satisfy the determination criterion is acquired as imaging conditions.

Claims

1. An X-ray inspection device that uses X-rays to carry out imaging to inspect an object, the X-ray inspection device comprising: an inspection time condition acquisition unit that receives an input from a user for selecting whether the inspection time should be changed or not; An imaging condition storage unit storing an imaging mode composed of a plurality of imaging parameters that determine imaging conditions, wherein the imaging mode is associated with whether the examination time is changed or not; a determination image acquisition unit that acquires a determination image for determining image quality from an X-ray image that is captured based on the imaging mode associated with whether the input inspection time is variable or constant; an image quality measuring unit configured to measure the image quality of the determination image; as well as an image quality determination unit for determining whether the measured image quality of the determination image satisfies a determination criterion, The image quality determination unit determines, as an imaging condition, the imaging parameter included in the imaging mode corresponding to the X-ray image when the determination image determined to satisfy the determination criterion is acquired.

2. An X-ray inspection device that uses X-rays to take images to inspect an object, the X-ray inspection device comprising: an inspection time condition acquisition unit that accepts an input from a user to minimize the inspection time; an imaging condition storage unit storing an imaging mode composed of a plurality of imaging parameters for determining imaging conditions, wherein the imaging mode is associated with the examination time; a determination image acquisition unit that acquires a determination image for determining image quality from an X-ray image captured based on the imaging mode; an image quality measuring unit configured to measure the image quality of the determination image; as well as an image quality determination unit for determining whether the measured image quality of the determination image satisfies a determination criterion, The image quality determination unit determines as an imaging condition the imaging parameters included in the imaging mode associated with the shortest inspection time among the inspection times associated with the imaging modes corresponding to the X-ray image when generating the determination image determined to satisfy the determination criterion.

3. An X-ray inspection device that uses X-rays to take images to inspect an object, the X-ray inspection device comprising: an inspection time condition acquisition unit that receives an input from a user to set the inspection time to a specific time or a specific time range; an imaging condition storage unit storing an imaging mode composed of a plurality of imaging parameters for determining imaging conditions, wherein the imaging mode is associated with the inspection time as the specific time or the specific time range; a determination image acquisition unit that acquires a determination image for determining image quality from an X-ray image that is captured based on the imaging mode associated with the input inspection time that is the specific time or the specific time range; an image quality measuring unit configured to measure the image quality of the determination image; as well as an image quality determination unit for determining whether the measured image quality of the determination image satisfies a determination criterion, The image quality determination unit determines, as an imaging condition, the imaging parameter included in the imaging mode corresponding to the X-ray image when the determination image determined to satisfy the determination criterion is acquired.

Images