JP2017142217A - Imaging apparatus and imaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain reconstructed images with high quality one after another.SOLUTION: A move part (20) of an imaging apparatus (1) has an attitude change part (23) for differentiating an attitude (P1) of a subject (7) to a light source (3) when passing through the interval between the light source (3) and a first detection part (13) from an attitude (P2) of the subject (7) to a light source (4) when passing through the interval between the light source (4) and a second detection part (14).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and an imaging method using radiation.

  Patent Documents 1 and 2 propose techniques for visualizing the inside of a subject by passing the subject between an X-ray light source and a detector by translation.

  In Patent Documents 1 and 2, the fluoroscopic images taken during parallel translation of the subject are rearranged and converted into a data string suitable for computed tomography (CT), which is a standard reconstruction method for CT. A back-projection (FBP) method is applied to obtain an image (reconstructed image) inside the subject.

  Patent Documents 1 and 2 basically have the same contents. Patent Documents 1 and 2 both have the same important formula for converting perspective image data described in the specification. In the present specification, the fluoroscopic imaging method as described in Patent Documents 1 and 2 is referred to as translational imaging.

  2. Description of the Related Art In recent years, Factory Automation (FA), in which products are carried on a belt conveyor or the like and processed one after another, is often used in the manufacturing process of industrial products. Since translational imaging has good compatibility with FA, it has a high technical value because it is an FA-embedded CT type inspection apparatus.

  Patent Document 3 proposes a technique for obtaining a reconstructed image having no angle limiting artifact as a reconstruction method. Patent Document 3 proposes a reconstruction method in which the SA (Simulated Annealing) method is applied to CT. In the following description, the reconstruction method described in Patent Document 3 may be referred to as SACT.

JP 2006-071472 A (published March 16, 2006) Japanese Unexamined Patent Publication No. 2007-139964 (released on June 7, 2007) Patent No. 5190825 (registered on February 8, 2013)

  In translational imaging, a perspective image corresponding to subject rotation necessary for CT is obtained using the spread angle of the X-ray light source.

  In CT, in order to obtain a clear image, a perspective image from a 180-degree azimuth is necessary in principle. However, since the actual light source has a spread angle of about 120 degrees, the angle range of the perspective image is limited. . In reconstruction from a perspective image with a limited angle, image quality is degraded.

  Both Patent Documents 1 and 2 have reported image quality degradation having the same characteristics. This image quality deterioration is called an angle limit artifact because it is derived from the angle limit of the fluoroscopic image.

  As described above, the techniques described in Patent Documents 1 and 2 can only obtain a reconstructed image with degraded image quality.

  The present invention has been made in view of the above problems, and an object thereof is to obtain high-quality reconstructed images one after another.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes a light source unit having one or a plurality of light sources that emit radiation, and a first and a first unit that electrically detect and detect the radiation emitted from the light source unit, respectively. A second detection unit; a light source unit; and a moving unit that relatively translates the subject so as to pass between the first and second detection units. The posture of the subject with respect to the light source unit when passing between the first detection unit and the posture of the subject with respect to the light source unit when passing between the light source unit and the second detection unit are different. It is characterized by having a posture change part to be made.

  According to the above configuration, the moving unit relatively translates the subject so as to pass between the light source unit and the first and second detection units. Accordingly, it is not necessary to provide a large driving mechanism as compared with the case where the subject is rotated, and the manufacturing cost of the apparatus can be reduced. In addition, the first and second detection units are connected to the light source unit while the moving unit relatively translates the subject so as to pass between the light source unit and the first and second detection units. By detecting the radiation emitted from each, a perspective image of the subject moving in parallel is obtained. As described above, the first and second detection units can quickly obtain a fluoroscopic image of a subject, and thus can photograph a plurality of subjects one after another (hereinafter sometimes referred to as “sequential photographing”). .

  Further, according to the above configuration, the moving unit includes the posture of the subject with respect to the light source unit when passing between the light source unit and the first detection unit, and the light source unit and the second detection unit. A posture changing unit that changes the posture of the subject with respect to the light source unit when passing between them. For this reason, the first detection unit and the second detection unit can obtain a plurality of fluoroscopic images obtained by photographing the subject from different angles. Then, by obtaining a reconstructed image based on a plurality of perspective images obtained by photographing the subject from different angles, it is possible to obtain a high-quality reconstructed image in which artifacts are suppressed.

  Thus, according to the above configuration, high-quality reconstructed images can be obtained one after another.

  In addition, the moving unit moves the subject in the first advancing direction so as to pass between the light source unit and the first detecting unit, and moves the subject in the second advancing direction. A second moving unit that passes between the light source unit and the second detection unit by being moved, and when viewed in plan, the first traveling direction and the second traveling direction may be different Good.

  With the above-described configuration, the posture changing unit moves the posture of the subject relative to the light source unit when passing between the light source unit and the first detection unit, and between the light source unit and the second detection unit. The posture of the subject with respect to the light source unit when passing can be made different. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  In addition, compared with the case where the first moving unit and the second moving unit are arranged so that the first moving direction and the second moving direction are the same, the length of the first moving unit and the second moving unit is longer. Of these, the length from one end of the first moving part to the other end of the second moving part can be shortened. Thereby, a 1st moving part and a 2nd moving part can be installed also in the installation space where the length from one edge part of the 1st moving part to the other edge part of the 2nd moving part is short.

  In addition, the moving unit moves the subject in the first advancing direction so as to pass between the light source unit and the first detecting unit, and moves the subject to the first advancing direction. A second moving unit that passes between the light source unit and the second detection unit by moving in the same second traveling direction, and when viewed in plan, the first traveling direction and the second traveling direction The posture changing unit changes the posture of the subject moved by the first moving unit in the first traveling direction to a different posture, and moves the subject to the second moving unit. It may be moved in the two traveling directions.

  With the above-described configuration, the posture changing unit moves the posture of the subject relative to the light source unit when passing between the light source unit and the first detection unit, and between the light source unit and the second detection unit. The posture of the subject with respect to the light source unit when passing can be made different. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  In addition, compared with the case where the first moving unit and the second moving unit are arranged so that the first moving direction and the second moving direction are different, of the lengths of the first moving unit and the second moving unit, The length in the direction perpendicular to the straight line from one end of the first moving part to the other end of the second moving part can be shortened. Thereby, among the lengths of the first moving unit and the second moving unit, the length in the direction perpendicular to the straight line from one end of the first moving unit to the other end of the second moving unit is short. The first moving unit and the second moving unit can also be installed in the installation space.

  The light source unit includes a first light source and a second light source that are the plurality of light sources, and the first moving unit moves the subject between the first light source and the first detection unit. The second moving unit may move the subject in the second moving direction between the second light source and the second detecting unit by moving in the first moving direction.

  According to the above configuration, the first light source emits radiation to the subject moving in the first traveling direction, and the second light source emits radiation to the subject moving in the second traveling direction. By emitting the light, the first detection unit and the second detection unit can photograph the subject from different angles. Therefore, it is not necessary to move the light source in order to photograph the subject from different angles in the first detection unit and the second detection unit. For this reason, since the drive mechanism for moving the light source can be omitted, the manufacturing cost of the apparatus can be reduced.

  Further, at least one of the first traveling direction and the second traveling direction may be inclined. Thereby, it can suppress that specific artifacts, such as a cone beam artifact, are contained in a reconstructed image, for example.

  Further, at least one of the first detection unit and the second detection unit may be configured by arranging a plurality of dot-shaped or linear detectors side by side. Thereby, compared with the case where the planar detector with a large area is arrange | positioned, an apparatus can be obtained cheaply.

  Alternatively, at least one of the first detection unit and the second detection unit may have a single planar light receiving unit. Thereby, compared with the case where a plurality of detectors are arranged side by side, a high-definition perspective image of the subject can be obtained. For this reason, a higher quality reconstruction image can be obtained.

  Further, if the radiation angle of the light source of the light source unit is 2θ degrees, and the number of times the posture changing unit changes the posture of the subject is N times, 1 ≦ N <(180 / 2θ). Also good. With the above configuration, the subject can be photographed evenly from the direction of 180 ° of the subject. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  Furthermore, a calculation unit may be provided that acquires intensity data of radiation detected by the first detection unit and the second detection unit and obtains a tomographic image of the subject from the intensity data. With the above configuration, the calculation unit performs reconstruction based on the perspective images obtained from the first detection unit and the second detection unit, and obtains a reconstructed image. In this way, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  The calculation unit may use a SACT method as a reconstruction method used when obtaining a tomographic image of the subject from the intensity data. With the above configuration, it is possible to obtain a reconstructed image having no angle limiting artifact from the perspective images obtained by the first detection unit and the second detection unit.

  In order to solve the above-described problems, an imaging method of the present invention includes a step of emitting radiation from a light source unit having one or a plurality of light sources, and first and first steps for electrically converting radiation emitted from the light source unit, respectively. 2 detecting by the detecting unit, and a moving step of relatively translating the subject so as to pass between the light source unit and the first and second detecting units, the moving step including the light source The posture of the subject with respect to the light source unit when passing between the light source unit and the first detection unit is different from the posture with respect to the light source unit when passing between the light source unit and the second detection unit. Including a posture changing step. According to the above configuration, high-quality reconstructed images can be obtained one after another.

  The present invention has an effect that high-quality reconstructed images can be obtained one after another.

It is a figure showing the structure of the imaging device 1 which concerns on Embodiment 1 of this invention. It is a perspective view showing schematic structure of the imaging device shown in FIG. (A) It is a figure showing the to-be-photographed object used for the Example of this invention, (b) is the figure reconfigure | reconstructed by the general CT method using the data which image | photographed the to-be-photographed object of (a) once. FIG. 8C is a diagram reconstructed from data obtained by performing parallel translation imaging of the subject shown in FIG. It is the perspective image obtained by image | photographing a to-be-photographed object with the imaging device which concerns on Embodiment 1 of this invention. (A) is a figure showing a mode that the square subject is image | photographed with the imaging device which concerns on Embodiment 1 of this invention, (b) is tilted according to the radiation angle of a light source, and the said imaging | photography is carried out. It is a figure showing a mode that it image | photographs with an apparatus. (A) is a figure showing schematic structure of the imaging device which concerns on Embodiment 2 of this invention, (b) is a figure showing schematic structure of the imaging device which concerns on the comparative example of the imaging device of (a). It is a figure which shows the experimental result which concerns on Example 2 of this invention. It is a figure showing schematic structure of the imaging device which concerns on Embodiment 3 of this invention. It is a figure showing schematic structure of the imaging device which concerns on Embodiment 4 of this invention. It is a figure showing the structure of the imaging device which concerns on Embodiment 5 of this invention.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail.

(Configuration of the imaging device 1)
FIG. 1 is a diagram illustrating a configuration of an imaging apparatus 1 according to Embodiment 1 of the present invention. FIG. 2 is a perspective view illustrating a schematic configuration of the photographing apparatus 1. FIG. 1 shows a typical layout of the photographing apparatus 1 according to the first embodiment. FIG. 1 is a view of the photographing apparatus 1 as seen from above so that the parallel movement path of the subject 7 can be clearly understood.

  FIG. 2 schematically shows, in three dimensions, the light source unit 2 (light sources 3 and 4) that emits radiation, the subject 7, and the parallel movement path of the subject 7 in the imaging apparatus 1. A plurality of line sensors 13 a and 14 a are vertically arranged with respect to the horizontal photographing apparatus 1.

  The photographing device 1 is a device that obtains a perspective image and a reconstructed image of the subject 7 by photographing the subject 7 while moving the subject 7 straight in parallel. In particular, the photographing apparatus 1 changes the traveling direction of the subject 7 a plurality of times, changes the posture (orientation) with respect to the light sources 3 and 4 used when photographing the subject 7 for each photographing, and photographs the subject 7.

  The imaging device 1 includes a light source unit 2, a first detection unit 13, a second detection unit 14, a moving unit 20, and a calculation unit 30.

  The light source unit 2 includes a plurality of light sources 3 and 4 that emit radiation having a predetermined radiation angle. In the present embodiment, the radiation emitted from the light sources 3 and 4 is assumed to be X-rays. The light sources 3 and 4 may be light sources that emit other radiation such as neutron rays and gamma rays instead of X-rays. The light source 3 and the light source 4 are arranged so that the X-ray emission directions are different by 90 °. In the present embodiment, the light source 3 and the light source 4 are light sources that emit X-rays 3a and 4a so that the radiation angle is 90 °. The radiation angles of the X-rays 3a and 4a between the light source 3 and the light source 4 are not limited to 90 °, and may be other angles such as 30 °, 60 °, and 120 °, for example.

  Both the light sources 3 and 4 are fixedly installed on one surface side of the moving subject 7 on one surface (front surface) and the other surface (back surface). As a result, both the X-rays 3a and 4a emitted from the light sources 3 and 4 pass through the inside of the subject 7 from one surface (front surface) of the subject 7 and the first detection unit 13 via the other surface (back surface). The light enters the second detection unit 14.

  The first detection unit 13 is a detector that detects the X-ray 3 a emitted from the light source 3 by electrical conversion. The first detection unit 13 is disposed to face the emission surface of the light source 3. The second detection unit 14 is a detector that detects the X-ray 4 a emitted from the light source 4 by performing electrical conversion. The second detection unit 14 is disposed to face the emission surface of the light source 4.

  The first detection unit 13 and the second detection unit 14 receive the X-rays 3a and 4a transmitted through the parallel moving subject 7 to obtain a perspective image of the subject 7. Then, the first detection unit 13 and the second detection unit 14 each output electrical data corresponding to the fluoroscopic image to the calculation unit 30.

  The first detection unit 13 and the second detection unit 14 may be a two-dimensional detector having a two-dimensional light receiving unit that can obtain a perspective image of the subject 7 that translates by a certain distance, or a plurality of detection units. It may be a line sensor that is a linear detector that can obtain a perspective image of the subject 7 that translates a certain distance by arranging the detectors in a straight line. One of the first detector 13 and the second detector 14 may be a two-dimensional detector, and the other may be a line sensor.

  Since the two-dimensional detector can obtain a high-definition perspective image, a higher-quality reconstructed image can be obtained. However, a two-dimensional detector is more expensive than a line sensor because it requires a large area. On the other hand, a line sensor has a smaller amount of data than a two-dimensional detector and cannot obtain a high-definition fluoroscopic image compared to a two-dimensional detector, but is inexpensive, so an industrial product is inspected on a production line. It is suitable as an inspection device.

  In the present embodiment, each of the first detection unit 13 and the second detection unit 14 is a line sensor in which a plurality of detectors 13a and 14a are arranged in a straight line. The first detection unit 13 and the second detection unit 14 may have a configuration in which a plurality of detectors are arranged side by side in a dot shape.

  As shown in FIG. 2, the detectors 13a and 14a constituting the line sensor are directions in which the extending direction is perpendicular to the floor surface. For this reason, in FIG. 1, the detectors 13a and 14a are viewed from above, and are drawn as small squares.

  The moving unit 20 translates the placed subject 7 a plurality of times or continuously in a substantially straight line. The movement part 20 can be comprised by moving apparatuses, such as a belt conveyor, for example. The moving unit 20 includes a first moving unit 21, a second moving unit 22, and a posture changing unit 23 that changes only the moving direction while keeping the absolute posture of the subject 7. The 1st moving part 21 and the 2nd moving part 22 are connected via the attitude | position change part 23, and the angle which the 1st moving part 21 and the 2nd moving part 22 comprise is 90 degrees in this embodiment. ing. In addition, the angle which the 1st moving part 21 and the 2nd moving part 22 comprise may be angles other than 90 degrees.

  The first moving unit 21 is disposed between the light source 3 and the first detection unit 13. The first moving unit 21 linearly translates the placed subject 7 in the direction of the traveling direction S1.

  The second moving unit 22 is disposed between the light source 4 and the second detection unit 14. The second moving unit 22 translates the subject 7 moved from the posture converting unit 23 in a straight line in the second traveling direction S2. The second traveling direction S2 is 90 ° different from the first traveling direction S1.

  The posture changing unit 23 is disposed adjacent to the first moving unit 21 on the traveling direction S1 side in which the first moving unit 21 in the first moving unit 21 moves the subject 7. The posture changing unit 23 is the posture of the subject 7 with respect to the light source 3 when passing between the light source 3 and the first detection unit 13 (that is, the direction of the subject 7 viewed from the light source 3), the light source 4, and the second detection. The posture of the subject 7 with respect to the light source 4 (that is, the orientation of the subject 7 as viewed from the light source 4) when passing between the unit 14 is made different. In this specification, the posture changing unit is referred to in the sense that the postures of the light source and the subject change. In a normal belt conveyor, the subject rotates and the postures of the light source and the subject are the same, so the posture changing unit 23 is necessary.

  For example, in the belt conveyor in which the second moving unit 22 and the posture changing unit 23 are integrally formed, the moving unit 20 is located on the side of the posture changing unit 23 in front of the traveling direction S1 of the first moving unit 21. It can comprise by connecting the edge part of the side.

  The moving unit 20 is assumed that the radiation angle of the X-rays 3a and 4a of the light sources 3 and 4 included in the light source unit 2 is 2θ degrees, and the number of times the posture changing unit 23 changes the posture of the subject 7 is an integer (natural number) N. The posture of the subject 7 is varied by 1 ≦ N <(180 / 2θ). In this embodiment, since the radiation angle of the X-rays 3a and 4a of the light sources 3 and 4 is 90 degrees, the posture changing unit 23 changes the posture of the subject 7 from the posture P1 to the posture P2 by 1 ≦ N <( Since 180 / 2θ) = 2 and N is an integer, that is, N = 1, the posture is changed only once. For example, if the radiation angle of the light source is 61 degrees, 1 ≦ N ≦ <2.95, and the number of times of changing the posture of the subject 7 can be set once or twice. When selecting the number of times, a value obtained by multiplying the radiation angle of the light source and (the number N + 1 of posture changes) should be close to 180 degrees. As described above, the posture changing unit 23 changes the posture of the subject 7 only N times satisfying 1 ≦ N <(180 / 2θ), whereby an artifact reduction effect can be obtained.

  When the calculation unit 30 acquires electrical data corresponding to the perspective image of the subject 7 from each of the first detection unit 13 and the second detection unit 14, the calculation unit 30 generates a reconstructed image from the perspective image by calculation.

  As a method for the calculation unit 30 to reconstruct from a fluoroscopic image, Filtered Back-projection, which is a standard CT reconstruction method, SACT described in Patent Document 3, and the like can be cited. Further, ART, SART SIRT, ILST, ML-EM, etc. may be used.

  The photographing apparatus 1 can also be expressed as a configuration in which parallel movement photographing units R1 and R2 for parallel photographing of the subject 7 are connected via the posture changing unit 23.

  The translational imaging unit R1 includes a pair of light sources 3 and a first detection unit 13, and a first movement unit 21. The translational imaging unit R2 includes a pair of light sources 4 and a second detection unit 14, and a second movement unit 22. Then, the posture changing unit 23 changes the posture of the subject 7 with respect to the light sources 3 and 4 for each of the parallel moving photographing units R1 and R2.

  As the translation imaging units R1 and R2, the translation imaging apparatus described in Patent Documents 1 and 2 may be used. In this case, as the translational imaging apparatus, the translational imaging apparatus described in either of Patent Documents 1 and 2 may be used. However, the inventor of Patent Document 1 is the same as the inventor according to the present application, and at present, the inventor of the present invention assumes the technical scope proposed in Patent Document 1. Therefore, it is preferable to use the translation imaging apparatus described in Patent Document 1 as the translation imaging units R1 and R2. Furthermore, the photographing apparatus 1 can also use the technique described in Patent Document 1, such as a technique for installing a shield according to the position of the sensor, a parallel moving photographing in which a subject / detector is fixed and a light source is moved. Good.

(Operation of the photographing apparatus 1)
As an example, the light source 3 emits an X-ray 3 a having a radiation angle 90 toward the first detection unit 13 when an X-ray output instruction is given from a light source control unit (not shown). Further, when an X-ray output instruction is given from a light source control unit (not shown), the light source 4 emits an X-ray 4a having a radiation angle 90 as an example toward the second detection unit 14.

  When the subject 7 is placed on the first moving unit 21 by the operator or the work robot, the first moving unit 21 emits the subject 7 from the light source 3 by translating the subject 7 in the first traveling direction S1. The X-ray 3a is allowed to pass through the radiation region. While passing through the radiation area of the X-ray 3a, the first detector 13 captures a fluoroscopic image of the subject 7. And the 1st moving part 21 carries out to the attitude | position change part 23 by parallelly moving the to-be-photographed object 7 to 1st advancing direction S1 as it is.

  Here, while the first moving unit 21 translates the subject 7 in the first traveling direction S <b> 1, the first moving unit 21 passes the subject 7 between the light source 3 and the first detection unit 13. In some cases, the posture P1 is held such that a part of the surface 7a faces the emission surface of the light source 3. Thus, when the subject 7 is viewed from the light source 3, a part of the surface 7a is mainly visible.

  Next, when the first moving unit 21 receives the subject 7 moved in the direction of travel S1, the posture changing unit 23 changes the direction of travel 90 ° from the direction of travel S1 and moves the subject 7 in the direction of travel S2. To the second moving unit 22.

  Here, the posture changing unit 23 changes the traveling direction of the subject 7 from the first traveling direction S1 to the second traveling direction S2, but does not change the absolute posture of the subject 7, thereby changing the second traveling direction. The posture of the subject 7 with respect to the direction S2 is changed to the posture P2.

  In other words, the posture 7 is changed so that the surface 7 b different from the surface 7 a faces the light exit surface of the light source 4 when passing between the light source 4 through which the subject 7 passes and the second detection unit 14 in the subsequent process. Then, the posture changing unit 23 carries the subject 7 a to the second moving unit 22.

  Next, the second moving unit 22 moves the subject 7 through the radiation region of the X-rays 4a emitted from the light source 4 by translating the subject 7 in the second traveling direction S2. While passing through the radiation region of the X-ray 4a, the second detection unit 14 captures a fluoroscopic image of the subject 7. And the 2nd moving part 22 carries out the to-be-photographed device 1 out of the imaging device 1 by parallelly moving the to-be-photographed object 7 to 2nd advancing direction S2 as it is.

  Here, while the second moving unit 22 translates the subject 7 in the second traveling direction S <b> 2, the second moving unit 22 passes the subject 7 between the light source 4 and the second detection unit 14. Sometimes, the other surface 7 b different from the partial surface 7 a is held in the posture P <b> 2 so as to face the emission surface of the light source 4. Thereby, when the subject 7 is viewed from the light source 4, a surface 7b different from the surface 7a is mainly seen.

  For this reason, the parallel moving image capturing unit R1 and the parallel moving image capturing unit R2 image the subject 7 from different directions.

  Then, the first detection unit 13 and the second detection unit 14 respectively output electrical data corresponding to the perspective images of the subject photographed from different directions to the calculation unit 30.

  The calculation unit 30 obtains one reconstructed image from the electrical data corresponding to the fluoroscopic images of the subject 7 taken from different directions acquired from the first detection unit 13 and the second detection unit 14.

Example 1
Next, Example 1 of the present invention will be described. As Example 1, the photographing apparatus 1 shown in FIGS. 1 and 2 was used.

  In the photographing apparatus 1 according to the first embodiment, the parallel moving photographing units R1 and R2 are photographing units having functions equivalent to those of the parallel photographing apparatus (equivalent to Patent Documents 1 and 2).

  The direction is changed by 90 ° between the first traveling direction S1 and the second traveling direction S2 in which the subject 7 is translated by the parallel photographing units R1 and R2. Along with this, the parallel movement path (the first moving unit 21 and the second moving unit 22) of the subject 7 is bent by 90 ° via the posture changing unit 23.

  The first moving unit 21 moves the subject 7 from the left side of FIG. 1 and moves the subject 7 in the first moving direction S1 in the parallel moving photographing unit R1, thereby performing parallel moving photographing of the subject 7. After the parallel photographing in the parallel photographing unit R1, the posture changing unit 23 changes the traveling direction of the subject 7 to the second traveling direction S2, and the second subject 7 is subsequently moved in the parallel photographing unit R2. By moving in the advancing direction S2, the subject 7 was photographed in parallel movement.

  Here, when the moving direction of the subject 7 is bent in the posture changing unit 23, the moving direction of the subject 7 is changed, but the absolute posture (orientation) of the subject 7 when the moving unit 20 is viewed in plan is changed. It is an important point that there is no. As a result, the posture of the subject 7 with respect to the light source 3 in the parallel photographing at the parallel photographing unit R1 and the posture of the subject 7 with respect to the light source 4 in the parallel photographing at the parallel photographing unit R2 are different. The angle range of the fluoroscopic image is different. For this reason, a perspective image having an angle that cannot be obtained by the parallel moving photographing of the parallel moving photographing unit R1 is obtained by the parallel moving photographing of the parallel moving photographing unit R2.

  As the first detection unit 13 and the second detection unit 14, the two-dimensional detectors disclosed in Patent Documents 1 and 2 may be used, but in the first embodiment, linear line sensors often used in FA. Is used. Although the line sensor is a one-dimensional sensor array, an image of the subject 7 (X-ray fluoroscopic image in the case of the first embodiment) is obtained when the subject 7 crosses perpendicularly to the extending direction of the detectors 13a and 14a. Can be obtained. The fluoroscopic image at that time is a fluoroscopic image in a direction connecting the light source 3 (light source 4) and the first detection unit 13 (second detection unit 14) which is a line sensor.

  In the first embodiment, a line sensor in which 12 detectors 13 a are arranged in a straight line is used as the first detection unit 13. Similarly, a line sensor in which twelve detectors 14 a are arranged in a straight line is used as the second detection unit 14.

  As the light sources 3 and 4, a light source in which the spread angle of the X-rays 3a and 4a is 90 degrees which is not technically unreasonable.

  According to the imaging apparatus 1 according to the first embodiment as described above, (i) twelve fluoroscopic images with angles of 90/12 = 7.5 degrees can be obtained by translational imaging with the translational imaging unit R1. And covers an angle range of 90 degrees. Next, (ii) in the translational imaging in the translational imaging unit R2, the remaining 90 ° range is similarly imaged, and 24 fluoroscopic images are obtained over a total of 180 °.

  Of course, as the number of detectors constituting the line sensor increases, the quality of the image inside the reconstructed subject 7 is improved.

  FIG. 3A shows a subject used in the embodiment. FIG. 3A shows an image of the surface of the subject 7 used in the example. In the first embodiment, for the sake of simplicity, an image showing the subject 7 in two dimensions is shown.

  FIG. 4 is a perspective image obtained by photographing the subject 7 with the photographing apparatus 1. The horizontal axis in FIG. 4 corresponds to the amount of movement of the subject 7 after the subject 7 enters the parallel moving photographing unit R1 and the parallel moving photographing unit R2. The vertical axis in FIG. 4 corresponds to the positions (numbers) of the detectors 13a and 14a in the first detector 13 and the second detector 14, respectively.

  In FIG. 4, (i) the perspective image A1 which is the upper half is a perspective image obtained by the translation imaging unit R1, and (ii) the perspective image A2 which is the lower half is obtained by the translation imaging unit R2. This is a perspective image.

  The layout of the photographing apparatus 1 that has photographed FIG. 4 is the same as that of the photographing apparatus 1 shown in FIG. The total number of line sensors is 24.

  FIG. 3 (b) is an image reconstructed by a general CT method using only one translational imaging data (transparent image A1 which is the upper half of FIG. 4) having a light source spread of 90 degrees. . The detector imaged in FIG. 3B is a line sensor, and the number of detectors is twelve.

  In the first embodiment, the fluoroscopic image data is considerably small, so that the image quality is considerably poor as shown in FIG. Originally the round part is almond-shaped, which is a characteristic of typical angle-limiting artifacts. Note that the same feature (angle restriction artifact) can also be confirmed in FIG.

  On the other hand, according to the photographing apparatus 1 according to the first embodiment, both the upper and lower half perspective image data in FIG. 4 are measured. For this reason, the result of reconstruction including both the perspective images A1 and A2 shown in FIG. 4 is shown in FIG.

  As shown in FIG. 3C, the image quality is poor due to the small amount of data of the fluoroscopic image, but it can be seen that the round part is not almond-shaped but round and is correctly reconstructed.

  Thus, according to the photographing apparatus 1, it can be seen that a high-quality reconstructed image can be obtained by significantly reducing the angle limiting artifact.

  Further, FIG. 3 (d) shows the result of reconstructing FIG. 4 including the perspective images A1 and A2 and reconstructing the result of reconstructing by the so-called SACT method disclosed in Patent Document 3.

  As shown in (d) of FIG. 3, by performing reconstruction using the SACT method, high-quality reconstruction in which artifacts are further reduced compared to the reconstructed image shown in (c) of FIG. 3. It can be seen that an image can be obtained.

  In consideration of applying the photographing apparatus 1 to an industrial product, it is assumed that the subject 7 is considerably large. For this reason, if the first detection unit 13 and the second detection unit 14 are two-dimensional image sensors, the size of the sensor becomes enormous. This is expensive and difficult to implement in practice.

  Therefore, in the first embodiment, line sensors are used as the first detection unit 13 and the second detection unit 14. When line sensors are used as the first detection unit 13 and the second detection unit 14, the number of fluoroscopic images is limited to several tens at most. The number is insufficient to apply the filtered back-projection method, which is a standard CT reconstruction method. Therefore, in the first embodiment, the method (SACT) of Patent Document 3 is used as the reconstruction method. ART, SART, SIRT, ILST, ML-EM, and the like are known as techniques that can be expected to have the same effect. These are methods classified as an iterative reconstruction method, and any method is suitable as a reconstruction method used in the photographing apparatus 1.

  As described above, the points of the first embodiment are (1) the point of performing the parallel movement photographing twice or more, and (2) the angle relationship between the light source 3 and the subject 7, the light source 4 and the subject 7, That is, the angle relationship is changed.

  In the photographing apparatus 1 shown in FIG. 1, the parallel movement path of the subject 7 is bent by the posture changing unit 23, but if the angle of the subject 7 with respect to the light source 3 and the angle of the subject 7 with respect to the light source 4 are changed. Since the traveling direction of the subject 7 is the same, the same effect can be obtained by changing the angle of the subject 7 by rotating the subject 7. This configuration will be described in a fifth embodiment described later.

(Main advantages of the photographing device 1)
As described above, in the photographing apparatus 1, the first moving unit 21 relatively translates the subject 7 so as to pass between the light source 3 and the first detection unit 13. The second moving unit 22 relatively translates the subject 7 so as to pass between the light source 4 and the second detection unit 14. Accordingly, it is not necessary to provide a large driving mechanism as compared with the case where the subject 7 is rotated, and the manufacturing cost of the apparatus can be reduced. Since it is easy to improve the accuracy of movement of the subject 7, a clear image can be easily obtained.

  Further, while the first moving unit 21 relatively translates the subject 7 so as to pass between the light source 3 and the first detecting unit 13, the first detecting unit 13 is emitted from the light source 3. By detecting the X-ray 3a, a perspective image of the subject 7 that moves in parallel is obtained. Then, while the second moving unit 22 relatively translates the subject 7 so as to pass between the light source 4 and the second detecting unit 14, the second detecting unit 14 is emitted from the light source 4. By detecting the X-ray 4a, a perspective image of the subject 7 that moves in parallel is obtained.

  As described above, the first detection unit 13 and the second detection unit 14 can quickly obtain a perspective image of the subject 7, and thus can “shoot one after another” of a plurality of subjects.

  Further, in the photographing apparatus 1, the posture changing unit 23 moves between the posture P <b> 1 of the subject 7 with respect to the light source 3 when passing between the light source 3 and the first detection unit 13, and between the light source 4 and the second detection unit 14. The posture P2 of the subject 7 with respect to the light source 4 when passing is different. Therefore, the first detection unit 13 and the second detection unit 14 can obtain a plurality of perspective images obtained by photographing the subject 7 from different angles. Then, by obtaining a reconstructed image based on a plurality of fluoroscopic images obtained by photographing the subject 7 from different angles, it is possible to obtain a high-quality reconstructed image in which artifacts are suppressed.

  Thus, according to the imaging device 1, high-quality reconstructed images can be obtained one after another.

  Further, when the moving unit 20 is viewed in plan, the first moving direction S1 in which the first moving unit 21 moves the subject 7 and the second moving direction S2 in which the second moving unit 22 moves the subject 7 are different. . In other words, the extending direction of the first moving unit 21 is different from the extending direction of the second moving unit 22, and the first moving unit 21 and the second moving unit 22 are bent by the posture changing unit 23. It is.

  Thereby, compared with the case where the 1st moving part 21 and the 2nd moving part 22 are arranged so that the 1st moving direction and the 2nd moving direction may become the same, the 1st moving part 21 and the 2nd moving part 22 are arranged. Of the first moving unit 21 from one end (the end opposite to the end connected to the posture changing unit 23) to the other end (posture changing unit) of the second moving unit. 23 to the end opposite to the end connected to the end 23) can be shortened. Thereby, the moving part 20 can be installed also in the installation space where the length from one end of the first moving part to the other end of the second moving part is short.

  The photographing apparatus 1 is not configured to have only one light source, but includes a light source 3 for photographing with the parallel moving photographing unit R1 and a light source 4 for photographing with the parallel photographing unit R2. . Therefore, the light source 3 emits X-rays 3a for the subject 7 moving in the first traveling direction S1, and the light source for the subject 7 moving in the second traveling direction S2 different from the first traveling direction S1. Since 4 emits the X-ray 4a, the first detection unit 13 and the second detection unit 14 can photograph the subject 7 from different angles. Thereby, it is not necessary to move the light source in order to photograph the subject 7 from different angles in the first detection unit 13 and the second detection unit 14. For this reason, since the drive mechanism for moving the light source can be omitted, the manufacturing cost of the apparatus can be reduced.

  In the present embodiment, since the radiation angle of the X-rays 3a and 4a of the light sources 3 and 4 included in the light source unit 2 is 90 degrees, the number N of times that the posture changing unit 23 changes the posture of the subject 7 is 1 ≦ Since N <(180/90) = 2, it is one time. Therefore, the posture changing unit 23 changes the subject 7 only once from the posture P1 to the posture P2. Thereby, the subject 7 can be photographed evenly from the direction of 180 ° of the subject 7. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

(Efficient shooting of subjects)
FIG. 5A is a diagram illustrating a state in which a quadrangular subject 7A is photographed by the photographing device 1, and FIG. 5B is a diagram illustrating the photographing of the rectangular subject 7A according to the radiation angle of the light source. It is a figure showing a mode that it is photographing.

  As described above, the remarkable effect of the photographing apparatus 1 is that “one after another photographing” is possible. That is, the next subject 7 can start to be shot before the parallel subject shooting of the preceding subject 7 is completed.

  In order to prevent the preceding subject and the fluoroscopic image from overlapping, a geometrical arrangement as shown in FIG. 5A is required. That is, the maximum angle (radiation angle) of the spread of the light source 3 is 2θ (when the spread is 90 degrees (= 2θ), θ is 45 degrees), and the range of the rectangular object 7A is a square of height D, and D tanθ It is obvious that the subject 7A should be spaced as much as possible. When θ is 45 degrees, tan θ is 1, so that an interval of D is provided. When the distance between the centers of the subject 7A is corrected, 2D is obtained.

  When the “shooting one after another” is performed by the photographing apparatus 1, the interval between the subjects 7A can be further narrowed.

  As shown in FIG. 5B, when the parallel photographing is performed twice by the photographing apparatus 1, the spread of the light sources 3 and 4 is 90 degrees, so it is sufficient to consider θ = 45 degrees. .

  At that time, if the area of the subject 7A is a square, the interval between the subjects 7A can be reduced to the limit by tilting the subject 7A area by 45 degrees. At that time, the distance between the centers of the subject 7A is √2 times D, and is about 1.4D. Compared to the case where the subject area is not tilted, the photographing interval of the subject 7A can be shortened by about 0.7 times.

  When the subject area is general, attention is paid to the outermost side of the light beam in the parallel shooting (the straight line connecting the light source 3 (light source 4) and the first detection unit 13 (second detection unit 14)), and both sides of the light beam. The distance at which the subject area touches the normal minimum distance. When the subject area is circular, the optimization as shown in FIG. 5B is not necessary, and when the diameter of the subject area is D, D / cos θ.

  The interval of the subject 7A at the time of “shooting one after another” is directly linked to the processing capability of the device based on the photographing device 1. The shooting time per subject when “subsequent shooting” where the subjects are continuously supplied as in the case of FA is much shorter than the exposure time of one subject. “Sequential imaging” is a feature in which the technique of the imaging apparatus 1 is decisively different from the conventional internal structure visualization technique based on CT.

[Embodiment 2]
A second embodiment of the present invention will be described with reference to FIGS. 6 to 7 as follows. For convenience of explanation, members having the same functions as those described in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the first embodiment, the spread of the X-rays 3a and 4a emitted from the light sources 3 and 4 is 90 degrees, so that the posture changing unit 23 bends 90 degrees so that the parallel imaging units R1 and R2 perform twice. The parallel movement was taken.

  However, even if the spread of the X-rays 3a and 4a emitted from the light sources 3 and 4 is less than 90 degrees, the effect of reducing artifacts can be obtained.

  6A is a diagram illustrating a schematic configuration of the imaging apparatus 1 according to Embodiment 2 of the present invention, and FIG. 6B is a schematic configuration of the imaging apparatus 100 according to the comparative example of the imaging apparatus 1 of FIG. FIG.

  The imaging apparatus 1 shown in FIG. 6A is different from the imaging apparatus 1 shown in FIGS. 1 and 2 in that the radiation angles of the X-rays 3a and 4a emitted from the light sources 3 and 4 are different. The other configuration of the imaging apparatus 1 shown in FIG. 6A is the same as that of the imaging apparatus 1 shown in FIGS.

  6A, the X-ray 3a radiation angle 2θ1 emitted from the light source 3, the X-ray 4a radiation angle 2θ2 emitted from the light source 4, the first moving unit 21 and the second moving unit 22 are included. Assuming that the formed angle is α1, in the photographing apparatus 1 according to the second embodiment, it is assumed that 2θ1 = 2θ2 = 60 degrees and α1 = 90 degrees.

  In the photographing apparatus 100 shown in FIG. 6B, the moving unit that translates the subject 7 is not bent and has a single linear shape. Further, the photographing apparatus 100 has only one light source 102. The light source 102 emits X-rays having a radiation angle 2θ100. It is assumed that 2θ100 = 120 degrees.

  That is, the photographing apparatus 1 according to the second embodiment includes the light sources 3 and 4 having a relationship of 2θ1 + 2θ2 = θ100.

  According to the photographing apparatus 1 according to the second embodiment, since the light sources 3 and 4 each have a radiation angle of 60 degrees, a fluoroscopic image of the subject 7 in a range of 60 + 60 = 120 degrees is obtained.

  However, since the bend of the moving path of the subject 7 (the angle α1 formed by the first moving unit 21 and the second moving unit 22) is 90 degrees, the actually obtained data is anomalous of 60 degrees + gap 30 degrees + 60 degrees. It will be a wide angle range. Although the angle limiting artifact appears, the way it appears is considerably less than the radiation angle of 120 degrees without a gap between the light sources as in the imaging device 100 shown in FIG.

  As described above, according to the photographing apparatus 1, a mild reconstructed image is obtained as compared with the photographing apparatus 100 having the single light source 102 having the radiation angle 2θ100 of the sum of the radiation angles of the light sources 3 and 4 (2θ1 + 2θ2). be able to. That is, a high-quality reconstructed image can be obtained.

(Example 2)
FIG. 7 shows a result of verifying the contents of the second embodiment.

  The image shown in FIG. 7A is an image obtained by reconstructing normal rotational CT imaging data in which the rotational angle range is limited to 120 degrees by the method of Patent Document 3. 7A corresponds to an image in which the light source emission angle is 60 degrees, the posture change count N is 1, and the posture change angle is 60 degrees. That is, it corresponds to a reconstructed image obtained by imaging with two light sources having a radiation angle of 60 degrees + 60 degrees with no gap between the X-ray data.

  FIG. 7 (b) shows translational imaging with a light source radiation angle of 60 degrees, a posture change angle of 90 degrees, and a posture change count N of 1, that is, by changing the radiation angle of the light source of the first embodiment, N = 1. It is a figure which shows the image which reconstructed fluoroscopic image data in the case using the method (SACT) of patent document 3. FIG. That is, FIG. 7B corresponds to a reconstructed image obtained by photographing with two light sources so that the radiation angle is 60 degrees + the gap is 30 degrees + the radiation angle is 60 degrees. The reconstructed image shown in (b) of FIG. 7 was obtained by photographing a parallel moving image with the radiation angle of the light source being 60 degrees twice by bending 90 degrees.

  In FIGS. 7A and 7B, the total range of light rays that can be used is 120 degrees, but in the reconstructed image shown in FIG. 7B, the angle limiting artifact is reduced.

  When the spread angle of the light source is 90 degrees or more, the angle ranges of the fluoroscopic images can be overlapped. In general CT, if there is an overlap in the fluoroscopic image, an artifact may occur, but the method (SACT) of Patent Document 3 does not cause a problem, and the present invention does not limit the spread angle of the light source.

  That is, unlike general CT, the X-rays 3a and 4a emitted from the light sources 3 and 4 in the imaging apparatus 1 may have overlapping emission areas. Also from this point, the imaging apparatus 1 is easy to handle and can have a simple apparatus configuration as compared with a general CT.

[Embodiment 3]
The third embodiment of the present invention will be described below with reference to FIG. For convenience of explanation, members having the same functions as those described in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 8 is a diagram illustrating a schematic configuration of an imaging apparatus according to Embodiment 3 of the present invention. FIG. 8A is a diagram illustrating a schematic configuration of an imaging apparatus 1A in which a movement path is bent twice, and FIG. It is a figure showing the schematic structure of the imaging device 1B in which the movement path | route is bent 3 times.

  The bend of the moving path of the subject 7 may be two or more times.

  An imaging apparatus 1A shown in FIG. 8A is an imaging apparatus having a configuration in which a moving path is bent twice.

  The imaging device 1A has a configuration in which the light source unit 2 and the moving unit 20 included in the imaging device 1 illustrated in FIG. 1 are changed to a light source unit 2A and a moving unit 20A. The other configuration of the imaging apparatus 1A is the same as that of the imaging apparatus 1.

  The light source section 2A includes light sources 3, 4, and 5 that emit radiation such as X-rays. When the radiation angles of X-rays and the like of the light sources 3, 4, and 5 are 2θ1, 2θ2, and 2θ3, respectively, it is assumed that 2θ1 = 2θ2 = 2θ3 = 60 degrees.

  The moving unit 20A further includes a third moving unit 24 and a posture changing unit 25 in addition to the first moving unit 21, the second moving unit 22, and the posture changing unit 23.

  The third moving unit 24 is connected to the second moving unit 22 via the posture changing unit 25. The third moving unit 24 translates the subject 7 carried out via the second moving unit 22 and the posture changing unit 25 to the end opposite to the side where the posture changing unit 25 is arranged. The function of the posture changing unit 25 is the same as that of the posture changing unit 23.

  When the angle formed by the first moving unit 21 and the second moving unit 22 is α1, and the angle formed by the second moving unit 22 and the third moving unit 24 is α2, α1 = α2 = 60 degrees.

  The relationship between the radiation angles 2θ1, 2θ2, 2θ3 of the X-rays and the like of the light sources 3, 4, 5 and α1 and α2 which are the bending angles of the parallel movement is 2θ1 = 2θ2 = 2θ3 = α1 = α2.

  As described above, in the imaging apparatus 1A, since the radiation angles of the X-rays 3a, 4a, and 5a of the light sources 3, 4, and 5 are 60 degrees, the number N of times that the posture of the subject 7 is changed by the posture changing units 23 and 25 is 1 ≦ N <(180/60) = 3 to 1 to 2 times, and N = 2 times from the condition that the product of the radiation angle 60 degrees of the light source and (N + 1) is close to 180 degrees. Thereby, the subject 7 can be photographed evenly from the direction of 180 ° of the subject 7. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  An imaging apparatus 1B shown in FIG. 8B is an imaging apparatus having a configuration in which the movement path is bent three times.

  The imaging device 1B has a configuration in which the light source unit 2A and the moving unit 20A included in the imaging device 1A illustrated in FIG. 8A are changed to the light source unit 2B and the moving unit 20B. Other configurations of the photographing apparatus 1B are the same as those of the photographing apparatus 1A.

  The light source unit 2B includes light sources 3, 4, 5, and 6 that emit radiation such as X-rays. If the radiation angles of X-rays and the like of the light sources 3, 4, 5 and 6 are 2θ1, 2θ2, 2θ3 and 2θ4, respectively, it is assumed that 2θ1 = 2θ2 = 2θ3 = 45 degrees.

  In addition to the 1st movement part 21, the 2nd movement part 22, the attitude | position change part 23, the 3rd movement part 24, and the attitude | position change part 25, the movement part 20B further has the 4th movement part 26 and the attitude | position change part 27. It has.

  The fourth moving unit 26 is connected to the third moving unit 24 via the posture changing unit 27. The fourth moving unit 26 translates the subject 7 carried out via the third moving unit 24 and the posture changing unit 27 to the end opposite to the side where the posture changing unit 27 is arranged. The function of the posture changing unit 27 is the same as that of the posture changing units 23 and 25.

  The angle formed by the first moving unit 21 and the second moving unit 22 is α1, the angle formed by the second moving unit 22 and the third moving unit 24 is α2, and the third moving unit 24 and the fourth moving unit 26 are formed. When the angle is α3, α1 = α2 = α3 = 45 degrees.

  The relationship between the radiation angles 2θ1, 2θ2, 2θ3, 2θ4 of the radiation of each of the light sources 3, 4, 5 and 6 and the parallel bending angles α1, α2, and α3 is 2θ1 = 2θ2 = 2θ3. = 2θ4 = α1 = α2 = α3.

  Thus, since the radiation angle of the X-rays 3a, 4a, 5a, and 6a of the light sources 3, 4, 5, and 6 is 45 degrees, the photographing apparatus 1B has the posture 7 of the subject 7 by the posture changing units 23, 25, and 27. The number of times N is different from 1 ≦ N <(180/45) = 4 to N = 1-3, and N = 3 from the condition that the product of the radiation angle 45 degrees of the light source and (N + 1) is close to 180 degrees. Times. Thereby, the subject 7 can be photographed evenly from the direction of 180 ° of the subject 7. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  As described above, when the folding is N times (N is a natural number), the translational shooting is N + 1 times. Since it is sufficient to cover 180 degrees in total, the angle of one bend is preferably 180 / (N + 1) degrees.

  When N = 1, it corresponds to the photographing apparatus 1 of the first embodiment by photographing twice with 90-degree bending.

  When N = 2, shooting is performed three times with a bend of 60 degrees (corresponding to the photographing apparatus 1A), and when N = 3, shooting is performed four times with a bend of 45 degrees (corresponding to the photographing apparatus 1B). At the present time, it is considered that N = 3 at most is practically valuable.

  FIG. 7C is a view showing an image obtained by reconstructing the fluoroscopic image data in the case of N = 2 in parallel movement shooting with a light source spread of 60 degrees by the method of Patent Document 3. (C) of FIG. 7 shows an experimental result in the case of N = 2 (parallel movement photographing with a light source spread of 60 degrees and folding twice by 60 degrees and photographing three times in total). As shown in FIG. 7C, a substantially complete reconstructed image is obtained as in FIG. 3D.

[Embodiment 4]
Embodiment 4 of the present invention will be described below with reference to FIG. For convenience of explanation, members having the same functions as those described in the first to third embodiments are denoted by the same reference numerals and description thereof is omitted.

  FIG. 9 is a diagram illustrating a schematic configuration of a photographing apparatus 1C according to the fourth embodiment of the present invention.

  In the photographing apparatus 1 shown in FIG. 1, the first traveling direction S1 and the second traveling direction S2 are horizontal. On the other hand, the photographing apparatus 1C shown in FIG. 9 is different from the photographing apparatus 1 (see FIG. 1) in that the traveling direction of the subject 7 is inclined so as to drop downward as it moves.

  The imaging device 1C has a configuration in which the first moving unit 21 of the imaging device 1 is changed to a first moving unit 21C in which an end connected to the posture changing unit 23 is inclined downward in both ends. is there. Further, the imaging apparatus 1C may be configured such that the second moving unit 22 of the imaging apparatus 1 is configured such that, of both ends, the end opposite to the end connected to the posture changing unit 23 is inclined upward. Good. The other configuration of the photographing apparatus 1C is the same as that of the photographing apparatus 1.

  The first moving unit 21C translates the subject 7 in the direction of the first advancing direction S11 in which the subject 7 moves in parallel so that the subject 7 gradually moves downward as the subject 7 moves.

  Here, the spread of the radiation angle of the light sources 3 and 4 also exists in the direction perpendicular to the parallel movement direction, that is, the depth direction of the paper surface in FIG. The spread of the light sources 3 and 4 in that direction causes cone beam artifacts when the perspective image is reconstructed.

  Therefore, when the cone beam artifact is remarkable, it is preferable to incline the parallel movement path of the subject 7. For example, in the photographing apparatus 1 shown in FIG. 1, in the parallel photographing with the parallel photographing unit R <b> 1, the direction toward the back with respect to the paper surface (the depth direction in FIG. 1, the first traveling direction shown in FIG. 9). In the parallel photographing by the parallel photographing unit R2, the parallel movement path of the subject 7 is inclined in the direction toward the front with respect to the paper surface.

  The degree of inclination is preferably in the range of light rays that pass through the subject 7. For example, if the light beam passing through the subject 7 is 15 degrees in the front and 15 degrees in the back, the inclination is about 15 degrees. When the height of the subject 7 (the depth direction in FIG. 1) is asymmetric, the average of the front side is a guide.

  Thus, cone beam artifacts can be effectively reduced by reversing the inclination of the moving direction of the subject 7 in the photographing with the parallel photographing unit R1 and the photographing with the parallel photographing unit R2. The reason why cone beam artifacts are reduced by the inclination of the translation path should be clarified academically.

[Embodiment 5]
The fifth embodiment of the present invention will be described below with reference to FIG. For convenience of explanation, members having the same functions as those described in the first to fourth embodiments are given the same reference numerals and explanation thereof is omitted.

  FIG. 10 is a diagram illustrating a configuration of an imaging device 1D according to the fifth embodiment of the present invention. The photographing apparatus 1D is different from the photographing apparatus 1 (see FIG. 1) in that the traveling direction of the subject 7 is not bent and the subject 7 rotates between the parallel moving photographing unit R1 and the parallel moving photographing unit R2. .

  The imaging device 1D includes a moving unit 20D instead of the moving unit 20 included in the imaging device 1. The moving unit 20D includes a first moving unit 21D, a posture changing unit 23D, and a second moving unit 22D that are arranged in a straight line.

  In the photographing apparatus 1D, a parallel moving photographing unit R11, a posture changing unit 23D, and a parallel moving photographing unit R12 are arranged in a straight line.

  The parallel movement photographing unit R11 includes a pair of light sources 3, a first detection unit 13, and a first movement unit 21D. The translation photographing unit R12 includes a pair of light sources 4 and a second detection unit 14, and a second movement unit 22D.

  The posture changing unit 23 changes the posture of the subject 7 with respect to the light sources 3 and 4 for each of the parallel moving photographing units R11 and R12. Specifically, the posture changing unit 23 rotates the subject 7 without changing the traveling direction of the subject 7. The posture changing unit 23D can be configured by an apparatus including a rotation mechanism, for example.

  When the subject 7 is placed on the first moving unit 21D by the operator or the working robot, the first moving unit 21D translates the subject 7 in the traveling direction (first traveling direction / second traveling direction) S13. By doing so, the X-ray 3a emitted from the light source 3 passes through the radiation region. While passing through the radiation area of the X-ray 3a, the first detector 13 captures a fluoroscopic image of the subject 7. And the 1st moving part 21D carries out to the attitude | position change part 23D by parallelly moving the to-be-photographed object 7 to the advancing direction S13 as it is.

  Here, while the first moving unit 21D translates the subject 7 in the traveling direction S13, the first moving unit 21D moves the subject 7 between the light source 3 and the first detecting unit 13. The posture 7 is held such that a part of the surface 7 a faces the emission surface of the light source 3. Thus, when the subject 7 is viewed from the light source 3, a part of the surface 7a is mainly visible.

  Next, when the first moving unit 21D receives the subject 7 moved in the traveling direction S13, the posture changing unit 23D holds the traveling direction of the subject 7 in the traveling direction S13 and when viewed in plan The direction of the subject 7 is rotated by 90 ° and carried out to the second moving unit 22D.

  In other words, the posture changing unit 23D has a posture in which a surface 7c different from the surface 7a faces the light emitting surface of the light source 4 when passing between the light source 4 through which the subject 7 passes and the second detection unit 14 in a subsequent process. Change to P3. Then, the posture changing unit 23D carries out the subject 7 to the second moving unit 22D.

  Next, the second moving unit 22D moves the subject 7 through the radiation region of the X-rays 4a emitted from the light source 4 by translating the subject 7 in the traveling direction S13. While passing through the radiation region of the X-ray 4a, the second detection unit 14 captures a fluoroscopic image of the subject 7. And 2nd moving part 22D carries out the to-be-photographed object 7D out of the imaging device 1D by parallelly moving the to-be-photographed object 7 to the advancing direction S13 as it is.

  Here, while the second moving unit 22D translates the subject 7 in the traveling direction S13, the second moving unit 22D moves the subject 7 between the light source 4 and the second detection unit 14. The other surface 7c, which is different from the surface 7a, is held in a posture P3 so as to face the emission surface of the light source 4. Thereby, when the subject 7 is viewed from the light source 4, a surface 7b different from the surface 7a is mainly seen.

  For this reason, the parallel movement photographing unit R11 and the parallel movement photographing unit R12 photograph the subject 7 from different directions.

  Then, the first detection unit 13 and the second detection unit 14 respectively output electrical data corresponding to the perspective images of the subject 7 photographed from different directions to the calculation unit 30.

  The calculation unit 30 obtains one reconstructed image from the electrical data corresponding to the fluoroscopic images of the subject 7 taken from different directions acquired from the first detection unit 13 and the second detection unit 14.

  As described above, in the photographing apparatus 1D, the moving unit 20D moves the subject 7 in the traveling direction S13 so that the first moving unit 21D that passes between the light source 3 and the first detecting unit 13 and the subject 7 are moved. The first moving unit 21D has a second moving unit 22D that passes between the light source 4 and the second detecting unit 14 by moving the first moving unit 21D in the same moving direction S13 as the moving direction.

  Then, the posture changing unit 23D changes the posture P1 of the subject 7 moved by the first moving unit 21D in the traveling direction S13 to a different posture P3 by rotating the subject 7, and changes the subject 7 in the posture P3 to the second state. The moving unit 22D is moved in the traveling direction S13.

  With the above configuration, the posture changing unit 23 </ b> D passes between the light source 4 and the second detection unit 14 and the posture P <b> 1 of the subject 7 with respect to the light source 3 when passing between the light source 3 and the first detection unit 13. The posture P3 of the subject 7 with respect to the light source 4 can be made different. Thereby, a high-quality reconstructed image in which artifacts are suppressed can be obtained.

  In addition, compared with the case where the first moving unit and the second moving unit are arranged so that the first moving direction and the second moving direction are different, the lengths of the first moving unit 21D and the second moving unit 22D are increased. Among them, one end of the first moving unit 21D (the end opposite to the end connected to the posture changing unit 23D) to the other end of the second moving unit (connected to the posture changing unit 23D). It is possible to shorten the length in the direction perpendicular to the straight line (the end on the side opposite to the end portion) (the length in the short direction perpendicular to the longitudinal direction of the moving portion 20D). As a result, of the lengths of the first moving part 21D and the second moving part 22D, a direction perpendicular to a straight line from one end of the first moving part 21D to the other end of the second moving part 22D. The moving unit 20D can be installed in an installation space having a short length (the length of the moving unit 20D in the short direction perpendicular to the longitudinal direction).

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

1, 1A-1D Imaging device 7, 7A Subject 2, 2A, 2B Light source unit 3-6 Light source 3a-6a X-ray (radiation)
21 · 21C · 21D First moving unit 13 First detector 14 Second detecting unit 13a · 14a Detectors 14, 22, 22D Second moving unit 14 Second detecting unit 20, 20A, 20B, 20D Moving unit 23 Posture change Unit 23 / 23D / 25/27 Posture changing unit 24 Third moving unit 26 Fourth moving unit 30 Computing unit P1, P2, P3 Posture R1, R2, R11, R12 Parallel moving photographing unit S1 First traveling direction S2 Second traveling Direction S13 Traveling direction (first traveling direction, second traveling direction)
α1 angle

Claims (10)

A light source unit having one or more light sources for emitting radiation;
A first and a second detector for detecting each of the radiation emitted from the light source unit by electrical conversion;
A moving unit that relatively translates the subject so as to pass between the light source unit and the first and second detection units;
The moving unit is configured such that the posture of the subject with respect to the light source unit when passing between the light source unit and the first detection unit, and the position when passing between the light source unit and the second detection unit. An image pickup apparatus comprising: a posture changing unit that makes the posture of the subject different from the light source unit. The moving part is
A first moving unit that moves between the light source unit and the first detection unit by moving the subject in a first traveling direction;
A second moving unit that moves between the light source unit and the second detection unit by moving the subject in a second advancing direction;
The imaging apparatus according to claim 1, wherein the first traveling direction and the second traveling direction are different when viewed in plan. The moving part is
A first moving unit that moves between the light source unit and the first detection unit by moving the subject in a first traveling direction;
A second moving unit that moves between the light source unit and the second detection unit by moving the subject in a second traveling direction that is the same as the first traveling direction;
When viewed in plan, the first traveling direction and the second traveling direction are the same direction,
The posture changing unit changes the posture of the subject moved by the first moving unit in the first traveling direction to a different posture, and moves the subject to the second moving direction by the second moving unit. The imaging apparatus according to claim 1. The light source unit includes a first light source and a second light source that are the plurality of light sources,
The first moving unit moves the subject in the first traveling direction between the first light source and the first detecting unit,
The imaging apparatus according to claim 2 or 3, wherein the second moving unit moves the subject in the second traveling direction between the second light source and the second detection unit.   The imaging apparatus according to claim 2, wherein at least one of the first traveling direction and the second traveling direction is inclined.   At least one of the first detection unit and the second detection unit is configured by arranging a plurality of dotted or linear detectors side by side, or one planar light receiving unit. The imaging apparatus according to claim 1, wherein the imaging apparatus has a configuration including:   When the radiation angle of the radiation of the light source included in the light source unit is 2θ degrees and the number of times the posture changing unit changes the posture of the subject is N times, 1 ≦ N <(180 / 2θ). The imaging device according to any one of claims 1 to 6.   2. The apparatus according to claim 1, further comprising a calculation unit that acquires intensity data of radiation detected by the first detection unit and the second detection unit and obtains a tomographic image of the subject from the intensity data. 8. The imaging device according to any one of items 7.   9. The imaging apparatus according to claim 8, wherein the arithmetic unit uses a SACT method as a reconstruction method used when obtaining a tomographic image of the subject from the intensity data. Emitting radiation from a light source unit having one or more light sources;
Detecting radiation emitted from the light source unit by first and second detection units, respectively;
A moving step of relatively translating the subject so as to pass between the light source unit and the first and second detection units,
The moving step includes the posture of the subject with respect to the light source unit when passing between the light source unit and the first detection unit, and the position when passing between the light source unit and the second detection unit. An imaging method comprising a posture changing step of changing a posture with respect to a light source unit.