WO2013039032A1

WO2013039032A1 - X-ray examination device, x-ray examination device control method, program for controlling x-ray examination device, and storage medium for storing program

Info

Publication number: WO2013039032A1
Application number: PCT/JP2012/073056
Authority: WO
Inventors: 信治杉田; 真之益田; 訓之加藤; 清村上
Original assignee: オムロン株式会社
Priority date: 2011-09-14
Filing date: 2012-09-10
Publication date: 2013-03-21
Also published as: JP2013061257A; TW201312102A

Abstract

Provided is an x-ray examination device in which image pick-up time becomes shorter. The processing executed by the x-ray examination device includes the following steps: a step (S710) in which, in a state where the focus point in an examination object is continually projected to the light receiving center of an x-ray detector, the x-ray detector and an image pick-up visual field are caused to move continuously on a trajectory established beforehand for the movement of the x-ray detector and the image pick-up visual field; a step (S720) in which during such movement, in target positions, an x-ray generator is driven so as to continuously project x-rays, and in a period in which the x-ray detector is in an exposed state, x-rays are projected; a step (S730) in which x-rays are exposed and a projection image is output; and a step (S760) in which if n pre-established exposures are performed ("YES" in step S750) 3D images are reconfigured from n projection images.

Description

X-ray inspection apparatus, control method for X-ray inspection apparatus, program for controlling X-ray inspection apparatus, and recording medium storing the program

The present invention relates to an X-ray inspection apparatus, and more particularly to an X-ray inspection apparatus for acquiring an X-ray image early.

In CT (Computed Tomography) automatic inspection equipment using X-rays, high speed is required for in-line inspection. As an example of an imaging system configuration for speeding up, for example, Japanese Patent Laying-Open No. 2009-156788 (Patent Document 1) describes an inspection object and a two-dimensional X-ray detector using XY axes that move on parallel planes. A technique for acquiring X-ray images (hereinafter referred to as “projection images”) from a plurality of different directions by moving them is disclosed.

JP 2009-156788 A

In an inclined CT automatic inspection apparatus having a mechanism capable of imaging the same part from a plurality of angles using a two-dimensional X-ray detector, the mechanism for changing the imaging angle is moved and stopped, and imaging (X-ray irradiation and X-rays) is performed. Detector exposure) is performed in series in time (so-called STOP & GO method). As a result, there is a problem in that the inspection time cannot be further shortened because the movement time of the mechanism that does not contribute to imaging results in a loss of the inspection time.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an X-ray inspection apparatus capable of speeding up the acquisition of X-ray images.

Another object of the present invention is to provide an X-ray inspection method that speeds up X-ray image acquisition. Another object of the present invention is to provide a program for controlling an X-ray inspection apparatus so that acquisition of an X-ray image is accelerated. Still another object of the present invention is to provide a computer-readable recording medium storing the program.

According to an embodiment, an X-ray inspection apparatus is provided for performing an image reconstruction process on an inspection target region by receiving X-rays transmitted through the inspection target region of an object with a plurality of detection surfaces. The The X-ray inspection apparatus includes an object moving mechanism for moving an object, an X-ray source for irradiating the object with X-rays, and an X-ray for detecting X-rays that have passed through the inspection object region. X-rays that have passed through one point of the inspection target area under a predetermined trajectory condition in which the detector, the detector moving mechanism for moving the X-ray detector, and the object and the X-ray detector move are set in advance. A position calculator configured to calculate a movement target position of the X-ray detector and a movement target position of the object so as to be projected onto the light receiving center of the X-ray detector, and a movement calculated by the X-ray detector; A detector position control unit for controlling the driving of the detector moving mechanism so as to move along a first trajectory of the trajectory conditions where the target position is located, and a moving target position where the object is calculated The object moving mechanism is moved so as to move along the second trajectory of the trajectory conditions being positioned. X-ray source for controlling the X-ray source to irradiate X-rays toward the object while the object position control unit for controlling movement, the X-ray detector and the object are moving An X-ray image for acquiring a plurality of projection images by exposing the X-ray detector a plurality of times to X-rays transmitted through the object while the control unit, the X-ray detector and the object are moving. An acquisition unit and a calculation unit for reconstructing a three-dimensional image from a plurality of projection images using a reconstruction algorithm are provided.

Preferably, the first trajectory and the second trajectory are circular trajectories. The detector moving mechanism is configured to move the X-ray detector so that the X-ray detector and the object move concentrically around the X-ray source, and the object moving mechanism moves the object. Is configured to move.

Preferably, the X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays on a plurality of detection surfaces with a rectangular field of view. The detector position control unit is configured to perform control to translate the X-ray detector along the first trajectory so that each rectangular side of the X-ray detector at each movement target position faces the same direction. Has been.

Preferably, the X-ray source control unit is configured to drive the X-ray source so as to continuously irradiate X-rays while the object and the X-ray detector are moving.

Preferably, the X-ray source control unit is configured to control the X-ray source so that the object is irradiated with the X-rays a plurality of times. The X-ray detector is configured to expose a plurality of times in accordance with the timing of X-ray irradiation.

According to another embodiment, X-rays that have passed through the inspection target region of the object are received by a plurality of detection surfaces using an X-ray detector, thereby executing an image reconstruction process for the inspection target region. A method for controlling a line inspection apparatus is provided. In this control method, X-rays that have passed through one point of the inspection target region are projected onto the light receiving center of the X-ray detector under a predetermined trajectory condition in which the object and the X-ray detector move. A step of calculating a movement target position of the line detector and a movement target position of the object, and an X-ray detector along a first orbit among the orbital conditions in which the calculated movement target position of the X-ray detector is located; , A step of moving the object along a second trajectory of trajectory conditions where the calculated movement target position of the object is located, and the X-ray detector and the object are moving A step of irradiating the X-ray toward the object, and by exposing the X-ray detector to the X-rays transmitted through the object a plurality of times while the X-ray detector and the object are moving, Using the reconstruction algorithm And a step of reconstructing a 3-dimensional image from the number of the projected image.

Preferably, the first trajectory and the second trajectory are circular trajectories. Moving the X-ray detector includes moving the X-ray detector such that the X-ray detector and the object move concentrically around the X-ray source, and moving the object Includes moving the object such that the X-ray detector and the object move concentrically about the X-ray source.

Preferably, the X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays on a plurality of detection surfaces with a rectangular field of view. The step of moving the X-ray detector includes a step of translating the X-ray detector along the first trajectory so that each side of the rectangle of the X-ray detector at each movement target position faces the same direction. .

Preferably, the step of irradiating the X-ray includes a step of continuously irradiating the X-ray while the object and the X-ray detector are moving.

Preferably, the step of irradiating the X-ray includes a step of irradiating the object with the X-ray a plurality of times. The step of acquiring a plurality of projection images includes a step of exposing a plurality of times according to the timing of irradiation with X-rays.

According to another embodiment, X-rays that have passed through the inspection target region of the object are received by a plurality of detection surfaces using an X-ray detector, thereby executing an image reconstruction process for the inspection target region. A program for controlling the line inspection apparatus is provided. The program projects an X-ray that has passed through one point of the inspection target area onto the light receiving center of the X-ray detector under a predetermined orbital condition in which the object and the X-ray detector move. A step of calculating the movement target position of the X-ray detector and the movement target position of the target object, and a first trajectory of the trajectory conditions where the calculated movement target position of the X-ray detector is located. A step of moving the X-ray detector, a step of moving the object along a second trajectory of the trajectory conditions where the calculated movement target position of the object is located, and the X-ray detector and the object A step of irradiating the object with X-rays while moving, and an X-ray detector that exposes the X-ray detector a plurality of times while the X-ray detector and the object move while the object is moving A step of acquiring a plurality of projection images and a reconstruction algorithm Using prism and a step of reconstructing a 3-dimensional image from a plurality of projection images.

Preferably, the first trajectory and the second trajectory are circular trajectories. The program executes the step of moving the X-ray detector so that the X-ray detector and the object move concentrically around the X-ray source as the step of moving the X-ray detector. The step of moving the object is executed so that the X-ray detector and the object move concentrically around the X-ray source.

Preferably, the X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays on a plurality of detection surfaces with a rectangular field of view. As a step of moving the X-ray detector, the program translates the X-ray detector along the first trajectory so that each side of the rectangle of the X-ray detector at each movement target position faces the same direction. Make the step execute.

Preferably, as a step of irradiating the X-ray, the program executes a step of continuously irradiating the X-ray while the object and the X-ray detector are moving.

Preferably, the program executes a step of irradiating the target object with X-rays a plurality of times as the step of irradiating X-rays, and according to a timing at which the X-rays are irradiated as a step of acquiring a plurality of projection images. The step of performing multiple exposures is executed.

According to another embodiment, a computer-readable non-volatile data recording medium storing any of the programs described above is provided.

In one aspect, an X-ray image necessary for X-ray inspection is acquired at high speed.
The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

2 is a block diagram showing a hardware configuration of an X-ray inspection apparatus 100. FIG. 3 is a flowchart showing a part of a series of processes executed by X-ray inspection apparatus 100. It is a figure showing the state to which the X-ray detector 23 and the imaging visual field 310 move from upper direction. 2 is a block diagram showing a hardware configuration of an X-ray inspection apparatus 400. FIG. It is the figure which looked at the X-ray inspection apparatus 400 from the top centering on the X-ray generator. FIG. 3 is a diagram showing the relative positions of an X-ray detector 23 and an X-ray generator 10 with an inspection object 20 as a reference. 7 is a flowchart showing a part of a series of processes executed by a calculation unit 410 included in the X-ray inspection apparatus 400. 3 is a timing chart showing an operation pattern of each component of the X-ray inspection apparatus 100. It is a timing chart showing the pattern of operation | movement of the X-ray inspection apparatus 400 which concerns on this Embodiment. It is a figure showing a part of structure of the X-ray inspection apparatus 1000. It is a figure showing transition of the image obtained in the state where X-ray detector 23 and inspection subject 20 rotated, respectively. 2 is a block diagram illustrating a hardware configuration of a computer system 1200. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
[Hardware configuration]
With reference to FIG. 1, the structure of the X-ray inspection apparatus 100 according to a certain situation is demonstrated. FIG. 1 is a block diagram illustrating a hardware configuration of the X-ray inspection apparatus 100.

The X-ray inspection apparatus 100 includes an X-ray generator 10, a stage 18, an X-ray detector driving unit 22, an X-ray detector 23, an image acquisition control mechanism 30, an input unit 40, and an output unit 50. , An X-ray source control mechanism 60, a calculation unit 70, and a memory 90.

The X-ray generator 10 includes an X-ray focal point 17. The X-ray detector driving unit 22 includes an orthogonal type biaxial robot arm 22.1 and a detector support unit 22.2. The image acquisition control mechanism 30 includes a detector drive control unit 32 and an image data acquisition unit 34. The calculation unit 70 includes an inspection target position control unit 80. An inspection object 20 is mounted on the stage 18.

The X-ray generator 10 outputs X-rays with the axis passing through the X-ray focal point 17 as the central axis. The X-ray generator 10 is controlled by the X-ray source control mechanism 60. The X-ray source control mechanism 60 controls the output of the electron beam. Specifically, the X-ray source control mechanism 60 receives designation of X-ray energy (tube voltage, tube current) from the calculation unit 70. The X-ray energy varies depending on the configuration of the inspection object 20.

The inspection object 20 is carried into the stage 18. The stage 18 is configured as an XYZ stage, for example, and can be moved to an arbitrary position. The stage 18 moves, for example, according to a circular or linear trajectory. In another aspect, the stage 18 may be configured to place the inspection object 20 at a position for inspection by moving in one direction like a belt conveyor.

The X-ray detector driving unit 22 moves the X-ray detector 23 to a designated position through a detector drive control unit 32 according to a command from the calculation unit 70. Further, the detector drive control unit 32 sends the position information of the X-ray detector 23 at that time to the calculation unit 70.

More specifically, in the X-ray detector driving unit 22, the robot arm 22.1 and the detector support unit 22.2 move the X-ray detector 23 to a designated position. For example, the X-ray detector driving unit 22 is configured as an XYθ operation mechanism capable of driving the X-ray detector 23 with XYθ degrees of freedom.

The X-ray detector driving unit 22 is not limited to the above-described configuration, and is configured to be capable of moving in the XY direction or rotating in the XY plane. Any device having the same function may be used.

The X-ray detector 23 is a two-dimensional X-ray detector that detects and images X-rays output from the X-ray generator 10 and transmitted through the inspection object 20. For example, the X-ray detector 23 is a CCD (Charge Coupled Device) camera, I.D. I (Image Intensifier) tube, space efficient FPD (Flat Panel Detector). The X-ray detector 23 is desirably highly sensitive so that it can be used for in-line inspection, and may be a direct conversion type FPD using CdTe.

The image acquisition control mechanism 30 controls driving of the X-ray detector 23 by the X-ray detector driving unit 22 and acquisition of image data from the X-ray detector 23. Specifically, the detector drive control unit 32 controls the X-ray detector drive unit 22 so as to move the X-ray detector 23 to the position specified by the calculation unit 70. The image data acquisition unit 34 acquires image data of the X-ray detector 23. When a plurality of X-ray detectors 23 are used, the image data acquisition unit 34 can acquire the image data of the X-ray detector 23 specified by the calculation unit 70.

The input unit 40 receives an instruction input from the user of the X-ray inspection apparatus 100. The input unit 40 is realized by, for example, a keyboard, a mouse, a touch panel, a wireless communication interface, or the like used in a known computer system.

The output unit 50 outputs measurement results and the like to the outside. The output unit 50 is realized, for example, as a monitor device that displays an X-ray image or the like configured by the calculation unit 70. In another aspect, the output unit 50 is realized as an interface that outputs an image signal.

The X-ray source control mechanism 60 controls the X-ray irradiation timing, irradiation time, and intensity by the X-ray generator 10.

The calculation unit 70 executes a program (not shown) stored in the memory 90 to control each unit, and executes predetermined calculation processing.

The inspection target position control unit 80 performs positioning necessary for X-ray imaging by controlling the movement of the stage 18.

The memory 90 stores a program for controlling the operation of the X-ray inspection apparatus 100, acquired X-ray image data, and the like.

[Control structure]
A control structure of the X-ray inspection apparatus 100 in a certain aspect will be described with reference to FIG. FIG. 2 is a flowchart showing a part of a series of processes executed by the X-ray inspection apparatus 100.

In step S102, the calculation unit 70 moves the visual field by driving the stage 18 on which the inspection object 20 is placed.

In step S104, the X-ray inspection apparatus 100 captures a fluoroscopic image. Specifically, the image data acquisition unit 34 receives X-ray image data irradiated from the X-ray generator 10 and transmitted through the inspection object 20 from the X-ray detector 23. Image data is stored in the memory 90.

In step S106, the calculation unit 70 inspects the fluoroscopic image obtained by imaging.
In step S108, the arithmetic unit 70 determines whether or not the reconstructed image needs to be inspected based on the inspection result. If calculation unit 70 determines that inspection of the reconstructed image is necessary (YES in step S108), control unit 70 switches control to step S110. When that is not right (it is NO at step S108), the calculating part 70 complete | finishes control.

In step S110, the calculation unit 70 executes a CT (Computed Tomography) imaging process for one field of view.

In step S112, the calculation unit 70 reconstructs an image of the inspection object 20 using the image obtained by the CT imaging process.

In step S112, the arithmetic unit 70 inspects the reconstructed image.
In step S116, operation unit 70 determines whether or not the inspection of the entire visual field has been completed. When calculating unit 70 determines that the inspection of the entire visual field has been completed (YES in step S116), it ends the inspection. If not (NO in step S116), operation unit 70 returns control to step S102.

[Moving the field of view]
With reference to FIG. 3, the movement of the X-ray detector 23 and the imaging visual field 310 in the X-ray inspection apparatus 100 will be described. FIG. 3 is a diagram illustrating a state in which the X-ray detector 23 and the imaging visual field 310 move from above.

In one aspect, the X-ray detector 23 and the imaging visual field 310 rotate counterclockwise about the X-ray generator 10 as a rotation center. The X-ray detector 23 moves on the trajectory of the X-ray detector trajectory 320, and the imaging visual field 310 included in the inspection target 20 moves on the trajectory of the imaging visual field trajectory 330.

For example, in the example shown in FIG. 3, the X-ray detector 23 is arranged at the target position D1 at the time when the inspection is started. At this time, the imaging visual field 310 included in the inspection target 20 is positioned at the target position V1. When the X-ray generator 10 emits X-rays in this state, a projection image P1 of the imaging field of view 310 is acquired.

Thereafter, the X-ray detector 23 is driven to move from the target position D1 to the target position D2. At this time, the stage 18 on which the inspection object 20 is placed also rotates by the same angle and moves to the target position V2. When the X-ray generator 10 emits X-rays in this state, a projection image P2 is acquired.

Thereafter, similarly, the projection image P3 is acquired at the target positions D3 and V3, and the projection image P4 is acquired at the target positions D4 and V4. When n projection images are required for reconstruction, movement to the target positions Dn and Vn and imaging are alternately performed.

[Hardware configuration]
With reference to FIG. 4, the structure of the X-ray inspection apparatus 400 which concerns on embodiment of a certain situation is demonstrated. FIG. 4 is a block diagram showing a hardware configuration of the X-ray inspection apparatus 400.

The X-ray inspection apparatus 400 includes an X-ray generator 10, a stage 18, an orthogonal type biaxial robot arm 22.1, a detector support unit 22.2, an X-ray detector 23, and a calculation unit 410. A main storage unit 420, an auxiliary storage unit 425, an input unit 40, an output unit 50, an X-ray detector position control mechanism 440, an X-ray image acquisition mechanism 445, an optical camera position control mechanism 450, A camera 460, an optical image acquisition mechanism 455, a stage position control mechanism 465, and an X-ray source control mechanism 60 are provided. An inspection object 20 is mounted on the stage 18. The inspection object 20 includes an imaging visual field 310.

The X-ray detector 23 is driven by the robot arm 22.1 and the detector support 22.2 so as to move on the X-ray detector trajectory 320.

The position of the inspection object 20 is positioned by the stage position control mechanism 465 so that the imaging visual field 310 moves on the imaging visual field trajectory 330 and is moved to the target position by the stage 18. At this time, the X-ray detector 23 and the stage 18 are respectively connected to the X-ray detector so that X-rays emitted from the X-ray generator 10 toward the imaging visual field 310 are always detected by the X-ray detector 23. It moves on the trajectory 320 and the imaging visual field trajectory 330.

The calculation unit 410 controls the operation of the X-ray inspection apparatus 400. For example, in a certain aspect, the calculation unit 410 sets conditions for outputting X-rays from the X-ray generator 10 according to the inspection object 20 and stores the conditions in the main storage unit 420. The conditions include, for example, an applied voltage to the X-ray generator 10 and an imaging time. The X-ray source control mechanism 60 controls X-ray irradiation by the X-ray generator 10 based on the conditions. The X-ray image acquisition mechanism 445 controls the X-ray exposure time by the X-ray detector 23 according to the set imaging time.

In a certain aspect, the calculation unit 410 executes processing for reconstructing a three-dimensional image of the inspection target 20 from the acquired projection image. In another aspect, the calculation unit 410 determines the quality of the inspection target 20. For example, the calculation unit 410 determines pass / fail of the inspection target 20 using the reconstructed three-dimensional image data or fluoroscopic data. In this case, the calculation unit 410 recognizes the shape of the solder ball and determines whether the inspection object 20 is good or not by determining whether the shape is within a predetermined allowable range. Note that an algorithm for determining pass / fail and input information for the algorithm differ depending on the inspection object 20. Therefore, an algorithm and input information corresponding to the type of the inspection object 20 are input from the input unit 40 as imaging condition information and stored in the main storage unit 420.

The main storage unit 420 is realized by an EEPROM (Electrically Erasable and Programmable Read-Only Memory), an HDD (Hard Disc Drive), or other storage device that can hold data in a nonvolatile manner. The main storage unit 420 executes an X-ray focal position and imaging conditions and other data, an operating system for controlling the operation of the X-ray inspection apparatus 400, an algorithm for determining pass / fail, and the above-described processes. The program is stored.

The auxiliary storage unit 425 is realized by a RAM (Random Access Memory) or other volatile memory. The auxiliary storage unit 425 holds the data generated by the arithmetic unit 410, the image data acquired by the X-ray image acquisition mechanism 445, the data input via the input unit 40, and the like in a volatile manner.

The X-ray detector position control mechanism 440 drives the robot arm 22.1 and the detector support unit 22.2 so as to move the X-ray detector 23 to the position specified by the calculation unit 410.

The X-ray image acquisition mechanism 445 receives, from the X-ray detector 23, X-ray image data irradiated from the X-ray generator 10 and transmitted through the inspection object 20. The image data is stored in the main storage unit 420.

The optical camera position control mechanism 450 controls the position of the camera 460 based on a command from the calculation unit 410. The camera 460 includes a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide Semiconductor), and other elements. Specifically, the optical camera position control mechanism 450 moves the position of the camera 460 in order to specify the inspection position of the inspection object 20, and images the inspection object 20 mounted on the stage 18.

The optical image acquisition mechanism 455 receives image data obtained by photographing with the camera 460 and stores the image data in the auxiliary storage unit 425. The calculation unit 410 causes the output unit 50 to output the image data. When the output unit 50 is realized as a monitor device, an image of the inspection target 20 is displayed.

The stage position control mechanism 465 performs positioning of the stage 18 necessary for X-ray imaging by moving the stage 18 based on the control of the calculation unit 410.

In one aspect, the X-ray detector position control mechanism 440 sets the X-ray detector 23 in advance while maintaining a state in which one point in the inspection target 20 is projected onto the light receiving center of the X-ray detector 23. The drive of the detector moving mechanism (for example, the robot arm 22.1 and the detector support unit 22.2) is controlled so as to move along the first track (for example, the X-ray detector track 320). The stage position control mechanism 465 maintains a state in which one point in the inspection object 20 is projected onto the light receiving center of the X-ray detector 23, while the inspection object 20 is set in a second trajectory (for example, imaging). The drive of the stage 18 is controlled so as to move along the visual field trajectory 330). The X-ray source control mechanism 60 controls the X-ray generator 10 to irradiate X-rays toward the inspection target 20 while the X-ray detector 23 and the inspection target 20 are moving. While the X-ray detector 23 and the inspection object 20 are moving, the X-ray image acquisition mechanism 445 exposes the X-ray detector 23 to the X-rays transmitted through the inspection object 20 a plurality of times, thereby Obtain a projection image. The calculation unit 410 reconstructs a three-dimensional image from the plurality of projection images obtained in this manner using a reconstruction algorithm.

In another aspect, the first trajectory and the second trajectory are circular trajectories. The X-ray detector position control mechanism 440 moves the X-ray detector 23 so that the X-ray detector 23 and the inspection object 20 move concentrically around the X-ray generator 10, and stage position control is performed. The mechanism moves the inspection object 20.

Preferably, the X-ray source control mechanism 60 drives the X-ray generator 10 so as to continuously irradiate X-rays while the inspection object 20 and the X-ray detector 23 are moving.

Preferably, the X-ray source control mechanism 60 controls the X-ray generator 10 to irradiate the inspection target 20 with X-rays a plurality of times. The X-ray detector 23 exposes a plurality of times in accordance with the timing of X-ray irradiation.

<Technology>
Here, with reference to FIG. 4 further, the technical idea of the X-ray inspection apparatus 400 is organized as follows.
(1) The X-ray detector 23 and the imaging visual field 310 are continuously on a predetermined moving trajectory in a state in which the point of interest in the inspection object 20 is always projected onto the light receiving center of the X-ray detector 23. Move to.
(2) During the movement of (1), the X-ray generator 10 emits X-rays continuously or during a period in which the X-ray detector 23 is in the exposure state.
(3) During the movement of (1), the X-ray detector 23 exposes the X-rays a plurality of times, and stores the X-ray images acquired by the plurality of exposures as a projection image.
(4) The plurality of projection images stored in (3) are converted into a three-dimensional image using a CT reconstruction algorithm.

According to this technical idea,
(A) With respect to the inspection object 20 in one imaging field of view, the position irradiated through the inspection object 20 and irradiated to the center of the X-ray detector 23 does not change during continuous operation.
(B) Since a plurality of projection images are obtained by controlling the exposure (shutter) timing of the X-ray detector 23, reconstruction is performed using these images.

As a result, the time required for imaging is shortened.
In the present embodiment, the case where the X-ray detector trajectory 320 and the imaging visual field trajectory 330 are circular trajectories is described, but the X-ray detector trajectory 320 and the imaging visual field trajectory 330 are not limited to circular trajectories. Polygonal and rectangular shapes may be used.

[Moving the field of view]
With reference to FIG. 5, the movement of the X-ray detector 23 and the imaging visual field 310 in the X-ray inspection apparatus 400 according to the present embodiment will be described. FIG. 5 is a view of the X-ray inspection apparatus 400 as viewed from above with the X-ray generator 10 as the center.

As shown in FIG. 5, the X-ray detector 23 moves on the X-ray detector trajectory 320 counterclockwise. Specifically, the X-ray detector 23 detects X-rays at least at the target positions D1, D2, D3, and D4 as exposure points for X-ray imaging. In the example shown in FIG. 5, the X-ray detector 23 does not rotate. However, in another aspect, the X-ray detector 23 may rotate.

Further, the imaging field of view 310 included in the inspection target 20 is X-rayed at the target positions V1, V2, V3, V4,... Vn as the positions for imaging, and the projection images P1 ′ and P2 ′. , P3 ′, P4 ′,... Pn ′ are acquired. Similar to the X-ray detector 23, in the example shown in FIG. 5, the imaging visual field 310 does not rotate, but in other aspects, the imaging visual field 310 may rotate.

As for the relationship between the target position of the X-ray detector 23 and the target position of the imaging visual field 310, the target of the X-ray detector 23 is on the line connecting the X-ray generator 10 and the target position Vn of the imaging visual field 310. The movement of the X-ray detector 23 and the imaging visual field 310 is controlled so that the position Dn exists. That is, the X-ray detector 23 and the imaging visual field 310 move with the same angular velocity with respect to the X-ray generator 10. At this time, the X-ray detector 23 continuously moves to the target positions D1 to Dn on the X-ray detector trajectory 320 while keeping the point of interest in the imaging field 310 at the center of the light receiving surface. While the imaging visual field 310 and the X-ray detector 23 are moving, the X-ray detector 23 exposes X-rays transmitted through the imaging visual field 310. Since the X-ray detector 23 moves while capturing the point of interest, the X-ray detector position control mechanism 440 and the stage position control mechanism 465 use the result of position measurement like a servo motor or linear motor. It is desirable to use a drive device capable of feedback control.

[Points of interest]
The point of interest will be described with reference to FIG. FIG. 6 is a diagram showing the relative positions of the X-ray detector 23 and the X-ray generator 10 with respect to the inspection object 20. That is, in the X-ray inspection apparatus 400 according to the present embodiment, the X-ray detector 23 and the X-ray generation viewed from the inspection object 20 with the inspection object 20 fixed in order to understand the point of interest. The relative position of the vessel 10 is shown.

The point of interest refers to one point in the inspection object 20 that is always captured by the center of the X-ray detector 23 in the projection image. The XY plane in the inspection object 20 where the point of interest exists is referred to as a surface of interest.

The inspection object 20 has a focused surface 610 as a surface to be inspected by the X-ray inspection apparatus 400. The focused surface 610 includes a focused point 620. The X-ray detector 23 synchronizes with the movement of the imaging visual field 310 so as to always capture the point of interest 620.

[Control structure]
With reference to FIG. 7, a control structure of X-ray inspection apparatus 400 according to the present embodiment will be described. FIG. 7 is a flowchart showing a part of a series of processes executed by the calculation unit 410 included in the X-ray inspection apparatus 400.

In step S710, the calculation unit 410 moves the X-ray detector 23 and the imaging field 310 in a state where the point of interest 620 in the inspection target 20 is always projected on the light receiving center of the X-ray detector 23. For this purpose, it is continuously moved on the predetermined trajectories (X-ray detector trajectory 320 and imaging visual field trajectory 330). In addition, the calculation unit 410 initializes a counter for calculating the number of exposures.

In step S720, calculation unit 410, while moving, at target position V1 (or D1), V2 (or D2), V3 (or D3), V4 (or D4),... Vn (or Dn). The X-ray generator 10 is driven so as to continuously irradiate X-rays, or the X-ray generator 10 is irradiated with X-rays while the X-ray detector 23 is in an exposure state.

In step S730, the X-ray detector 23 exposes the X-rays, outputs a projection image (projection image), and transmits the projection image to the X-ray image acquisition mechanism 445. The projection image data is stored in the main storage unit 420. Thereafter, in a certain aspect, in order to speed up the image reconstruction process, the calculation unit 410 inputs the acquired projection image to the three-dimensional image reconstruction calculation and starts the image reconstruction process. As another aspect, a configuration in which the image reconstruction process is started after a necessary number of projection images are acquired can be used.

In step S740, the calculation unit 410 increments the number of exposures by the X-ray detector 23 by one.

In step S750, calculation unit 410 determines whether or not a preset number of projection images have been acquired. For example, the calculation unit 410 determines whether or not the number of exposures is the same as the preset number n. If calculation unit 410 determines that the number of exposures is the same as preset number n (YES in step S750), control unit 410 switches control to step S760. If not (NO in step S750), operation unit 410 switches control to step S730. The X-ray detector 23 exposes X-rays again.

In step S760, the acquisition of n projection images P1 'to Pn is completed. The calculation unit 410 configures a three-dimensional image of the inspection object 20 from the n projection images stored in the main storage unit 420 using a CT reconstruction algorithm. As described in step S730, it is desirable to input the projection image to the three-dimensional image reconstruction calculation at the imaging location every time one projection image is captured in order to speed up the X-ray examination. . For example, the calculation unit 410 performs a reconstruction calculation using the first projection image while acquiring the second projection image.

[Operation pattern of X-ray inspection equipment]
The operation pattern of the X-ray inspection apparatus will be described with reference to FIGS. FIG. 8 is a timing chart showing an operation pattern of each component of the X-ray inspection apparatus 100. FIG. 9 is a timing chart showing an operation pattern of the X-ray inspection apparatus 400 according to the present embodiment.

Referring to FIG. 8, as shown in graph 810, X-ray inspection apparatus 100 has an operation pattern of an X-ray detector position control mechanism (for example, robot arm 22.1 and detector support unit 22.2). , Repeat stop and move. At this time, as is apparent from the

graphs

810 and 820, in a certain situation, the stage position control mechanism (for example, the stage 18) and the X-ray detector 23 move asynchronously and reach their target positions at different timings. Stop.

When the X-ray detector 23 and the inspection object 20 are positioned, imaging is performed. Specifically, as shown in a graph 840, the X-ray generator 10 repeats stopping and X-ray irradiation. At this time, as indicated by a graph 830, the X-ray detector 23 repeats stop and exposure in synchronization with the operation of the X-ray generator 10. As shown in FIG. 8, in the X-ray inspection apparatus 100, the X-ray imaging operation time is taken in addition to the projection images P1, P2, P3, P4,. Including the period when is not conducted. That is, since the X-ray imaging can be performed only when the X-ray detector 23 is at the target position, the imaging time is limited.

On the other hand, referring to FIG. 9, in the X-ray inspection apparatus 400 according to the present embodiment, the X-ray detector 23 always moves while capturing a point of interest that is one point of the inspection object 20. The X-ray detector 23 is always in a state where X-rays can be detected. That is, X-ray imaging can be performed even while the X-ray detector 23 and the stage 18 are moving toward the target position.

Specifically, as shown in the graph 910, when the X-ray detector position control mechanism 440 starts moving from the stopped state, the X-ray detector 23 is continuously moved along the X-ray detector trajectory 320. Moving. As apparent from the graph 920, the stage 18 on which the inspection object 20 is mounted starts moving on the imaging visual field trajectory 330 in synchronization with the movement of the X-ray detector 23.

In synchronization with the start of movement of the X-ray detector 23 and the stage 18, the X-ray generator 10 starts X-ray irradiation as shown in the graph 940. Here, in the present embodiment, since the X-ray detector 23 always captures the point of interest, the X-ray detector 23 can always detect the X-ray transmitted through the inspection object 20. Accordingly, as shown in the graph 930, the X-ray detector 23 obtains the number of projection images necessary for reconstructing the three-dimensional image of the inspection target 20, according to the imaging conditions set in advance. The exposure is stopped according to the number. In this way, since exposure only needs to be stopped in order to obtain a plurality of projection images, it is not necessary to stop exposure until the positioning of the mechanism is completed. Therefore, the time for acquiring the required number of projection images is shorter than the time for the conventional imaging pattern.

As described above, according to the X-ray inspection apparatus 400 according to the present embodiment, the movement of the X-ray detector 23 and the stage 18 (so-called “mechanical movement”) and imaging are performed in parallel. In the X-ray inspection apparatus, the total time of the movement time and the imaging time for acquiring the same exposure time and the same number of projection images is shorter than the total time when the conventional X-ray inspection apparatus is used. The line imaging inspection can be speeded up.

<Second Embodiment>
Hereinafter, a second embodiment will be described. The X-ray inspection apparatus 1000 according to the present embodiment has a configuration in which the X-ray detector 23 and the inspection object 20 each rotate about a rotation axis, and thus the X-ray inspection apparatus according to the first embodiment. Different from 400.

Therefore, the configuration of the X-ray inspection apparatus 1000 according to the present embodiment will be described with reference to FIG. FIG. 10 is a diagram showing a part of the configuration of the X-ray inspection apparatus 1000. Note that the mechanism for controlling the operation of the X-ray inspection apparatus 1000 is realized by using the same hardware configuration as that of the X-ray inspection apparatus 400 according to the first embodiment. Therefore, those descriptions are not repeated.

As shown in FIG. 10, the X-ray inspection apparatus 1000 further includes an X-ray detector rotation mechanism 1010 and an inspection object rotation mechanism 1020 in addition to the configuration of the X-ray inspection apparatus 400. The X-ray detector rotation mechanism 1010 rotates the X-ray detector 23 about the rotation axis 1011. That is, the X-ray detector 23 rotates. The inspection object rotation mechanism 1020 rotates the inspection object 20 around the rotation shaft 1021. That is, the position of the stage 18 is controlled so that the inspection object 20 rotates. At this time, the rotation angle around the rotation axis 1011 and the rotation angle around the rotation axis 1021 are maintained at the same angle. Thereby, when a three-dimensional image is reconstructed using an image obtained by imaging at each rotation angle, the image of the target tomogram is not blurred.

An image obtained by the X-ray inspection apparatus 1000 according to the second embodiment will be described with reference to FIG. FIG. 11 is a diagram illustrating the transition of images obtained in a state where the X-ray detector 23 and the inspection object 20 are rotated.

In the state 1111, the inspection object 1120 included in the inspection object 20 is imaged as the first imaging. Specifically, an X-ray image of the inspection object 1120 is acquired as an image 1101. When the exposure of the X-ray detector 23 is completed (when imaging is completed), the X-ray detector 23 and the inspection object 20 move on the X-ray detector trajectory 320 and the imaging visual field trajectory 330, respectively, and rotate. , Transition to state 1112.

In state 1112, the X-ray detector 23 is exposed again. An X-ray image of the inspection object 1120 is acquired as an image 1102. When the exposure is completed, the X-ray detector 23 and the inspection object 20 further move and rotate, and the state transitions to the state 1113.

When exposure is performed in the state 1113, an image 1103 is acquired. Thereafter, the X-ray detector 23 and the inspection object 20 move and rotate, and transition to the state 1114. Further, when exposure is performed in the state 1114, an image 1104 is acquired. In this way, a projection image necessary for reconstructing the image to be inspected is acquired.

Since each of the

images

1101, 1102, 1103, and 1104 is acquired as an image rotated around the rotation axis centered on the point of interest, each image has already been positioned. Therefore, the image 1130 obtained by reconstructing these images is derived as a clear image without blurring.

As described above, according to the X-ray inspection apparatus 1000 according to the present embodiment, it is not necessary to stop rotation during imaging, so that X-ray imaging can be performed at high speed.

Note that the control mechanism of the X-ray inspection apparatuses 400 and 1000 according to the above-described embodiments can be realized by using a computer system having a known configuration.

Therefore, a computer system 1200 that realizes a control mechanism of the X-ray inspection apparatuses 400 and 1000 will be described with reference to FIG. FIG. 12 is a block diagram showing a hardware configuration of computer system 1200.

The computer system 1200 includes, as main components, a CPU 1 that executes a program, a mouse 2 and a keyboard 3 that receive input of instructions from a user of the computer system 1200, data generated by execution of a program by the CPU 1, or a mouse 2 Alternatively, a RAM 4 that stores data input via the keyboard 3 in a volatile manner, a hard disk 5 that stores data in a nonvolatile manner, an optical disk drive device 6, a monitor 8, and a communication IF (Interface) 9 are provided. Each component is connected to each other by a bus. A CD-ROM 9 and other optical disks are mounted on the optical disk drive 6.

Processing in the computer system 1200 is realized by software executed by each hardware and the CPU 1. Such software may be stored in the hard disk 5 in advance. In some cases, the software is stored in a CD-ROM 9 or other computer-readable data recording medium and distributed as a program product. Alternatively, the software may be provided as a program product that can be downloaded by an information provider connected to the Internet or other networks. Such software is read from the data recording medium by the optical disk drive 6 or other data reading device, or downloaded via the communication IF 7 and then temporarily stored in the hard disk 5. The software is read from the hard disk 5 by the CPU 1 and stored in the RAM 4 in the form of an executable program. The CPU 1 executes the program.

Each component constituting the computer system 1200 shown in FIG. 12 is a general one. Accordingly, it can be said that the essential part of the present invention is software stored in the RAM 4, the hard disk 5, the CD-ROM 9, or other data recording medium, or software that can be downloaded via a network. Since the operation of each hardware of computer system 1200 is well known, detailed description will not be repeated.

Data recording and recording media are not limited to CD-ROM, FD (Flexible Disk), and hard disk, but are magnetic tape, cassette tape, optical disk (MO (Magnetic Optical Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc). )), IC (Integrated Circuit) card (including memory card), optical card, mask ROM, EPROM (Electronically Programmable Read-Only Memory), EEPROM (Electronically Erasable Programmable Read-Only Memory), semiconductor memory such as flash ROM, etc. It may be a medium that carries a fixed program.

Here, the program may include not only a program that can be directly executed by the CPU, but also a program in a source program format, a compressed program, an encrypted program, and the like.

Although the invention has been described and shown in detail, it is clearly understood that this is by way of example only and should not be taken as a limitation, the scope of the invention being construed by the appended claims Will.

1 CPU, 2 mouse, 3 keyboard, 4 RAM, 5 hard disk, 6 optical disk drive, 8 monitor, 9 CD-ROM, 10 X-ray generator, 17 X-ray focal point, 18 stage, 20 inspection object, 22 X-ray Detector drive unit, 22.1 robot arm, 22.2 detector support unit, 23 X-ray detector, 30 image acquisition control mechanism, 32 detector drive control unit, 34 image data acquisition unit, 40 input unit, 50 output Unit, 60 X-ray source control mechanism, 70, 410 calculation unit, 80 inspection target position control unit, 90 memory, 100, 400, 1000 X-ray inspection device, 310 imaging field, 320 X-ray detector trajectory, 330 imaging field trajectory , 420 Main storage unit, 425 Auxiliary storage unit, 440 X-ray detector position control mechanism, 445 X-ray image acquisition Structure, 450 optical camera position control mechanism, 455 optical image acquisition mechanism, 460 camera, 465 stage position control mechanism, 610 focus surface, 620 focus point, 1010 line detector rotation mechanism, 1011, 1021 rotation axis, 1020 inspection object rotation mechanism .

Claims

An X-ray inspection apparatus for performing a reconstruction process of an image of the inspection target area by receiving X-rays transmitted through the inspection target area of the object with a plurality of detection surfaces,
An object moving mechanism for moving the object;
An X-ray source for irradiating the object with X-rays;
An X-ray detector for detecting X-rays transmitted through the inspection object region;
A detector moving mechanism for moving the X-ray detector;
The X-ray is transmitted to the light receiving center of the X-ray detector under a predetermined orbital condition in which the object and the X-ray detector move. A position calculation unit configured to calculate a movement target position of the line detector and a movement target position of the object;
Detector position control for controlling the driving of the detector moving mechanism so that the X-ray detector moves along a first trajectory of the trajectory conditions where the calculated movement target position is located. And
An object position control unit for controlling driving of the object moving mechanism so that the object moves along a second trajectory of the trajectory conditions where the calculated movement target position is located; ,
An X-ray source control unit for controlling the X-ray source so as to irradiate X-rays toward the object while the X-ray detector and the object are moving;
An X-ray image for acquiring a plurality of projection images by exposing the X-ray detector a plurality of times to X-rays transmitted through the object while the X-ray detector and the object are moving. An acquisition unit;
An X-ray inspection apparatus comprising: an arithmetic unit configured to reconstruct a three-dimensional image from the plurality of projection images using a reconstruction algorithm.
The first trajectory and the second trajectory are circular trajectories;
The detector moving mechanism is configured to move the X-ray detector so that the X-ray detector and the object move concentrically around the X-ray source, and the object The X-ray inspection apparatus according to claim 1, wherein the moving mechanism is configured to move the object.
The X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays on the plurality of detection surfaces with a rectangular field of view,
The detector position controller controls the X-ray detector to translate along the first trajectory so that the rectangular sides of the X-ray detector at the movement target positions face the same direction. The X-ray inspection apparatus according to claim 1, wherein the X-ray inspection apparatus is configured to perform the following.
The X-ray source control unit is configured to drive the X-ray source so as to continuously irradiate X-rays while the object and the X-ray detector are moving. The X-ray inspection apparatus according to 1 or 2.
The X-ray source control unit is configured to control the X-ray source so as to irradiate the object multiple times with X-rays,
The X-ray inspection apparatus according to claim 1, wherein the X-ray detector is configured to perform the exposure a plurality of times according to a timing at which the X-ray is irradiated.
A control method for an X-ray inspection apparatus that performs an image reconstruction process on an inspection target region by receiving X-rays transmitted through the inspection target region of an object using an X-ray detector on a plurality of detection surfaces. There,
The X-ray is transmitted to the light receiving center of the X-ray detector under a predetermined orbital condition in which the object and the X-ray detector move. Calculating a movement target position of the line detector and a movement target position of the object;
Moving the X-ray detector along a first trajectory of the trajectory conditions where the calculated movement target position of the X-ray detector is located;
Moving the object along a second trajectory of the trajectory conditions where the calculated movement target position of the object is located;
Irradiating X-rays toward the object while the X-ray detector and the object are moving;
Obtaining a plurality of projection images by exposing the X-ray detector a plurality of times to X-rays transmitted through the object while the X-ray detector and the object are moving;
Reconstructing a three-dimensional image from the plurality of projection images using a reconstruction algorithm.
The first trajectory and the second trajectory are circular trajectories;
Moving the X-ray detector includes moving the X-ray detector such that the X-ray detector and the object move concentrically around the X-ray source;
The step of moving the object includes the step of moving the object so that the X-ray detector and the object move concentrically around the X-ray source. Control method for X-ray inspection apparatus.
The X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays on the plurality of detection surfaces with a rectangular field of view,
The step of moving the X-ray detector includes paralleling the X-ray detector along the first trajectory so that each side of the rectangle of the X-ray detector at each movement target position faces the same direction. The method for controlling an X-ray inspection apparatus according to claim 6, comprising a moving step.
8. The X-ray inspection apparatus according to claim 6 or 7, wherein the step of irradiating the X-ray includes a step of continuously irradiating the X-ray while the object and the X-ray detector are moving. Control method.
The step of irradiating the X-ray includes a step of irradiating the object with X-rays a plurality of times,
The method for controlling the X-ray inspection apparatus according to claim 6 or 7, wherein the step of acquiring the plurality of projection images includes a step of performing exposure a plurality of times in accordance with a timing at which the X-ray is irradiated.
In order to control an X-ray inspection apparatus that performs an image reconstruction process on the inspection target region by receiving X-rays transmitted through the inspection target region of the target object on a plurality of detection surfaces using an X-ray detector. And the program is stored in the X-ray inspection apparatus.
The X-ray is transmitted to the light receiving center of the X-ray detector under a predetermined orbital condition in which the object and the X-ray detector move. Calculating a movement target position of the line detector and a movement target position of the object;
Moving the X-ray detector along a first trajectory of the trajectory conditions where the calculated movement target position of the X-ray detector is located;
Moving the object along a second trajectory of the trajectory conditions where the calculated movement target position of the object is located;
Irradiating X-rays toward the object while the X-ray detector and the object are moving;
Obtaining a plurality of projection images by exposing the X-ray detector a plurality of times to X-rays transmitted through the object while the X-ray detector and the object are moving;
A program for controlling an X-ray inspection apparatus that executes a step of reconstructing a three-dimensional image from the plurality of projection images using a reconstruction algorithm.
The first trajectory and the second trajectory are circular trajectories;
The program is
As the step of moving the X-ray detector, the step of moving the X-ray detector so that the X-ray detector and the object move concentrically around the X-ray source,
The step of moving the object is executed as the step of moving the object so that the X-ray detector and the object move concentrically around the X-ray source. A program for controlling the described X-ray inspection apparatus.
The X-ray detector is a rectangular X-ray detector for receiving and imaging X-rays at the plurality of detection surfaces with a rectangular field of view,
The program is
As the step of moving the X-ray detector, the X-ray detector is paralleled along the first trajectory so that the sides of the rectangle of the X-ray detector at each movement target position face the same direction. The program for controlling the X-ray inspection apparatus of Claim 11 or 12 which performs the step to move.
The program is
The X-ray inspection apparatus according to claim 11, wherein, as the X-ray irradiation step, a step of continuously irradiating X-rays while the object and the X-ray detector are moving is executed. Program to control.
The program is
As the step of irradiating the X-ray, the step of irradiating the object with X-rays a plurality of times is performed,
The program for controlling the X-ray inspection apparatus according to claim 11 or 12, wherein, as the step of acquiring the plurality of projection images, a step of performing a plurality of exposures according to a timing at which the X-ray is irradiated is executed.
A computer-readable non-volatile data recording medium storing the program according to any one of claims 11 to 15.