Panoramic X-ray equipment

Abstract

To prevent an X-ray detecting unit including an X-ray detector from contacting the shoulders of a subject while improving the resolution of a panoramic image.SOLUTION: A panoramic X-ray imaging apparatus 20 includes: an X-ray generating unit; an X-ray detecting unit 44; a support 40 (for example, a turning arm) that supports the X-ray generating unit and the X-ray detecting unit 44; a drive mechanism 60 that turns at least the X-ray generating unit and the X-ray detecting unit 44 by driving the support 40; a displacement mechanism 82 ( for example, a vertical drive unit) that adds movement including a displacement component in a direction different from the turning to the X-ray detecting unit 44; a subject holding unit 32 that holds an imaging subject M; and a turning control unit (for example, an imaging control unit 100) that controls the turning by the drive mechanism and the displacement mechanism. The turning control unit controls the drive mechanism 60 and the displacement mechanism 82 so as to add the movement to the X-ray detecting unit 44, the movement avoiding the contact with the shoulders of the imaging subject during the turning of the X-ray generating unit and the X-ray detecting unit by the drive mechanism 60 during the panoramic X-ray imaging.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] This disclosure relates to a technique for performing panoramic X-ray imaging by rotating an X-ray generator and an X-ray detector around a subject.

Background Art

[0002] Patent Document 1 discloses detecting the possibility of a patient hitting their shoulder by means of shoulder hit detection means such as a camera, and warning of a shoulder hit when a shoulder hit is detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, there is a demand for improving the resolution of a panoramic image (the expressiveness of details in the imaging target area). The resolution of a panoramic image improves as the X-ray detector gets closer to the imaging target area.

[0005] According to Patent Document 1, when a shoulder hit is warned, the patient's posture is corrected. However, correcting the patient's posture is not linked to bringing the X-ray detector closer to the imaging target area. For this reason, it is difficult to improve the resolution of a panoramic image.

[0006] Therefore, an object of the present disclosure is to improve the resolution of a panoramic image while suppressing the X-ray detection unit including the X-ray detector from hitting the shoulder.

Means for Solving the Problems

[0007] To solve the above problems, a panoramic X-ray imaging apparatus includes an X-ray generation unit including an X-ray generator, an X-ray detection unit including an X-ray detector, a support unit that supports the X-ray generation unit and the X-ray detection unit so that the X-ray generation unit and the X-ray detection unit face each other, a drive mechanism that rotates at least the X-ray generation unit and the X-ray detection unit by driving the support unit, a displacement mechanism that adds a movement including a displacement component in a direction different from the rotation direction to the X-ray detection unit, a subject holding unit that holds a subject to be imaged, and a swing control unit that controls the driving of the support unit by the drive mechanism and the addition of the movement to the X-ray detection unit by the displacement mechanism so as to perform panoramic X-ray imaging by rotating around the head of the subject held by the subject holding unit with the head of the subject held by the subject holding unit positioned between the X-ray generation unit and the X-ray detection unit. The swing control unit controls the drive mechanism and the displacement mechanism so as to add a movement that avoids contact with the shoulders of the subject to be imaged to the X-ray detection unit during the rotation of the X-ray generation unit and the X-ray detection unit by the drive mechanism during the panoramic X-ray imaging.

Advantages of the Invention

[0008] It is possible to improve the resolution of the panoramic image while suppressing contact of the X-ray detection unit including the X-ray detector with the shoulders.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Mode for Carrying Out the Invention

[0010] {First Embodiment} Hereinafter, the panoramic X-ray imaging apparatus according to the first embodiment will be described.

[0011] <Overall Configuration> The overall configuration of an X-ray imaging apparatus, which is an example of a panoramic X-ray imaging apparatus, will be described. FIG. 1 is a perspective view showing the X-ray imaging apparatus 20. In FIG. 1, a part of the configuration is shown by functional blocks. FIG. 2 is a partial cross-sectional side view showing the X-ray imaging apparatus 20.

[0012] For convenience of explanation, the directions are defined. The XYZ orthogonal coordinate system is an orthogonal coordinate system defined in the three-dimensional space where the imaging main body 30 is installed. The direction parallel to the axial direction of the turning axis X1 in the mechanism described later is the Z-axis direction. In the present embodiment, the direction parallel to the axial direction of the turning axis X1 in the mechanism and the moving direction by the vertical drive unit 82 described later coincide as the Z-axis direction. The direction orthogonal to the Z-axis direction is the Y-axis direction, and the direction orthogonal to both the Z-axis direction and the Y-axis direction is the X-axis direction. The front-rear direction of the head P of the imaging subject M held by the subject holding unit 32 is the Y-axis direction, and the left-right direction of the head is the X-axis direction. In the present application, the Z-axis direction may also be referred to as the Z direction, the Y-axis direction as the Y direction, and the X-axis direction as the X direction. Regarding the line-of-sight direction, for example, the line-of-sight direction from the -Z side to the +Z side is called the +Z direction view, etc., and the line-of-sight direction from the -○ (○ is any one of X, Z, Y) side to the +○ side or the line-of-sight direction parallel to it is defined as the "+○ direction view", and the line-of-sight direction from the +○ side to the -○ side or the line-of-sight direction parallel to it is defined as the "-○ direction view". When simply stating the "○ direction view", it may be either the +○ direction view or the -○ direction view. A two-dimensional plane having an extent in the X direction and the Y direction is referred to as the XY plane, and a two-dimensional plane having an extent in the ○ direction and the △ (△ is any one of X, Z, Y) direction may be expressed as the "○△ plane".

[0013] The side from the head P toward the base 80B, that is, the lower side, is the -Z side, and conversely, the side away from the base 80B from the head P, that is, the upper side, is the +Z side. The front side of the head P is the +Y side, and the rear side is the -Y side. The right side of the head P viewed from the face side is the +X side, and the left side is the -X side. Each axial direction is illustrated in FIGS. 1 and 2.

[0014] The X-ray imaging apparatus 20 includes, for example, an imaging main body 30 and an X-ray image processing apparatus 180 (also simply referred to as the image processing apparatus 180). The imaging main body 30 is configured to be capable of performing panoramic X-ray imaging. In addition to panoramic X-ray, the imaging main body 30 may be configured to be capable of performing at least one of, for example, simple transmission X-ray imaging, X-ray computed tomography (CT) imaging, and cephalometric imaging. The imaging main body 30 performs X-ray imaging such as panoramic X-ray imaging to collect X-ray imaging data (also referred to as projection data). The collected X-ray imaging data is processed by the X-ray image processing apparatus 180 to generate various X-ray images (specifically, X-ray CT imaging images, panoramic imaging images, cephalometric imaging images, etc.). In this example, the X-ray image processing apparatus 180 processes the X-ray imaging data collected by panoramic X-ray imaging processing to generate a panoramic X-ray image. Note that the panoramic X-ray image is an X-ray image in which the dental arch is continuously represented by X-ray transmission images in a direction orthogonal to the dental arch. Depending on the part of the dental arch, the orthogonality may be slightly avoided in order to avoid the reflection of other hard tissues such as the jawbone. In such a panoramic X-ray image, adjacent teeth are represented without overlapping as much as possible. The X-ray imaging apparatus 20 may be configured as a device that collects X-ray imaging data, and may be configured such that the X-ray image processing apparatus 180 is omitted. The X-ray imaging apparatus 20 may be configured to include only some functions of the X-ray image processing apparatus 180.

[0015] The imaging main body 30 includes an X-ray generation unit 42, an X-ray detection unit 44, a swing arm 40 which is an example of a support unit, a drive mechanism 60, a vertical drive unit 82 which is an example of a displacement mechanism, and an imaging control unit 100.

[0016] The X-ray generation unit 42 includes an X-ray generator 43 that generates X-rays. The X-ray detection unit 44 includes an X-ray detector 45 that detects X-rays. The swivel arm 40 supports the X-ray generation unit 42 and the X-ray detection unit 44 such that the X-ray generation unit 42 and the X-ray detection unit 44 face each other. The drive mechanism 60 drives the swivel arm 40. The drive is, for example, a swivel drive. The drive mechanism 60 drives the swivel arm 40 to at least swivel the X-ray generation unit 42 and the X-ray detection unit 44. The vertical drive unit 82 is a mechanism that adds movement including a displacement component in a direction different from the swivel by the drive mechanism 60 to the X-ray detection unit 44. The added displacement component is, for example, a direction parallel to the swivel axis X1 by the drive mechanism 60, that is, the vertical direction (Z-axis direction). During panoramic X-ray imaging, the imaging subject M is held in a fixed position by the subject holding unit 32. The subject holding unit 32 is preferably positioned so as to preferably fix and restrict the movement of the head P of the imaging subject during X-ray imaging. With the imaging subject M held by the subject holding unit 32, under the control of the imaging control unit 100, with the head P of the imaging subject M held by the subject holding unit 32 positioned between the X-ray generation unit 42 and the X-ray detection unit 44, the drive of the swivel arm 40 by the drive mechanism 60 and the addition of movement to the X-ray detection unit 44 by the vertical drive unit 82 are controlled so that the X-ray generation unit 42 and the X-ray detection unit 44 swivel around the head P to perform panoramic X-ray imaging. The movement of the X-ray detection unit 44 added by the imaging control unit 100 is a movement that can avoid contact with the shoulder S of the imaging subject M during the swivel of the X-ray generation unit 42 and the X-ray detection unit 44.

[0017] Each component configuration will be described more specifically.

[0018] The turning arm 40 is formed in a shape that is long in one direction. The turning arm 40 is provided, for example, along the horizontal direction. An X-ray generating unit 42 is provided in a hanging manner at one end of the turning arm 40, and an X-ray detecting unit 44 is provided in a hanging manner at the other end of the turning arm 40. Thereby, the X-ray generating unit 42 and the X-ray detecting unit 44 face each other in a state where the head P can be arranged between the X-ray generating unit 42 and the X-ray detecting unit 44. In this state, the X-ray generating unit 42 irradiates the head P with an X-ray beam. The X-ray detecting unit 44 receives and detects the X-ray beam that has passed through the head P.

[0019] The X-ray generating unit 42 includes an X-ray generator 43 and an X-ray beam shape adjusting unit 50. In the present embodiment, the X-ray generating unit 42 further includes a housing 41 that houses the X-ray generator 43 and the X-ray beam shape adjusting unit 50. The housing 41 includes a bottom portion and a peripheral wall portion that surrounds the space above the bottom portion. The housing 41 is supported so as to protrude downward at one end of the turning arm 40.

[0020] The X-ray generator 43 includes an X-ray tube that is an X-ray source for generating X-rays. The intensity (output intensity) of the X-ray beam emitted from the X-ray generator 43 is controlled by changing the voltage and / or current supplied to the X-ray tube. The control of the X-ray generator 43 (specifically, the control of the voltage amount and / or current amount) is performed by the irradiation control unit 102d of the imaging control unit 100.

[0021] The X-ray beam shape adjusting unit 50 restricts the spread of the X-ray beam emitted from the X-ray generator 43 and adjusts the X-ray beam to a shape according to the imaging purpose. That is, the X-ray beam shape adjusting unit 50 controls the irradiation range of X-rays on the imaging subject (object) M. The X-ray beam shape adjusting unit 50 is controlled by the irradiation control unit 102d.

[0022] Referring to FIGS. 3 and 4, a configuration example of the X-ray beam shaping unit 50 will be described. The X-ray beam shaping unit 50 includes two shielding members 52A, a shielding member driving unit 53A that drives the two shielding members 52A to open and close, two shielding members 52B, and a shielding member driving unit 53B that drives the two shielding members 52B to open and close. In FIGS. 3 and 4, the shielding members 52A, 52B and the parts (such as motors, shafts, etc.) that drive the shielding members 52A, 52B are shown by solid lines or hidden lines (broken lines), and the guides 53A1, 53B1 are shown by virtual lines (two-dot chain lines).

[0023] The shielding members 52A, 52B are made of a material (such as lead) that absorbs X-rays and are formed in a rectangular plate shape.

[0024] Of the four shielding members 52A, 52B, two of the shielding members 52A are provided at the upper and lower positions on the front side of the emission port of the X-ray generator 43. The opposite sides of the two shielding members 52A are along the horizontal direction.

[0025] The shielding member driving unit 53A drives the two shielding members 52A to approach and separate along the vertical direction. For example, the shielding member driving unit 53A includes two guides 53A1, two shafts 53A2, and two motors 53A3 that drive the two shafts 53A2. The shielding member 52A and the shaft 53A2 can be configured such that a screw portion provided on the outer periphery of the shaft 53A2 is screwed into a screw groove provided in the shielding member 52A, and the shielding member 52A is displaced by the rotational drive of the shaft 53A2. Individual drive controls may be performed, such as one of the shielding members 52A being driven by one of the shafts 53A2 and the other of the shielding members 52A being driven by the other of the shafts 53A2.

[0026] A pair of guides 53A1 supports both ends of the two shielding members 52A so as to be movable in the vertical direction.

[0027] The two shielding members 52A are individually driven to move in the vertical direction.

[0028] Of the four shielding members 52A and 52B, the other two shielding members 52B are provided at left and right positions on the front side of the emission port of the X-ray generator 43 at positions different from those of the two shielding members 52A in the X-ray emission direction from the X-ray generator 43. The sides of the two shielding members 52B that face each other are along the vertical direction.

[0029] The shielding member drive unit 53B drives the two shielding members 52B to approach and separate along the left-right direction. The shielding member drive unit 53B and the shielding members 52B may be configured in the same structure as the shielding member drive unit 53A and the shielding members 52A, except that the driving and moving directions are different. The driving and moving directions may be different by 90° around the axis of the X-ray irradiation axis in terms of angle. Then, by the clockwise or counterclockwise rotational drive of the two motors 53B3, the two shielding members 52B are individually driven to move in the left-right direction.

[0030] In addition, as the shielding member drive units 53A and 53B, other mechanisms such as a linear motor mechanism, a rack and pinion mechanism, and a mechanism using a belt and a pulley may be used.

[0031] In this example, according to the openings 55H1 and 55H2 formed by the two inner sides on the upper and lower sides that face each other of the two shielding members 52A and the two inner sides on the left and right sides that face each other of the two shielding members 52B, the shape of the X-ray beam, the position of the irradiation target, etc. are adjusted.

[0032] For example, when the two inner sides on the upper and lower sides that face each other of the two shielding members 52A are widely opened and the two inner sides on the left and right sides that face each other of the two shielding members 52B are widely opened, a rectangular opening 55H1 (see FIG. 3) is formed. The X-ray beam emitted from the X-ray generator 43 passes through this rectangular, for example, square-shaped opening 55H1, and is formed into an X-ray cone beam that spreads in a frustum of a regular square pyramid shape. Such an X-ray cone beam is used, for example, in CT imaging.

[0033] Further, for example, when the upper and lower two inner sides facing each other among the two shielding members 52A are widely opened, and the left and right two inner sides facing each other among the two shielding members 52B are slightly opened, an elongated opening 55H2 is formed (see FIG. 4). The X-ray beam emitted from the X-ray generator 43 passes through the vertically elongated slit-shaped opening 55H2, and is formed into an X-ray slit beam that spreads in a frustum of a pyramid shape elongated vertically. Such an X-ray slit beam is used, for example, in panoramic X-ray imaging.

[0034] While maintaining the shape of the opening 55H2, by moving the two shielding members 52B in the same direction, for example, the right direction, the irradiation target of the X-ray slit beam can be scanned from the left direction to the right direction. Also, while maintaining the shape of the opening 55H2, by moving the two shielding members 52B in the same direction, for example, the upward direction, the irradiation target of the X-ray slit beam can be moved from the downward direction to the upward direction.

[0035] By this X-ray beam shape adjuster 50, for example, at the time of panoramic X-ray imaging, the X-ray beam irradiated from the X-ray generator 43 can be formed into an X-ray slit beam in which the center beam CB, which is the center of the X-ray beam, is incident obliquely downward from above with respect to the body axis (vertical direction) of the subject M and has a length in the direction of the body axis (see FIG. 2). The angle θ of the center beam CB with respect to the horizontal direction Hr may be, for example, 4 degrees to 8 degrees. In this way, when the X-ray beam is incident on the subject M obliquely downward from above with respect to the horizontal direction, on the panoramic image, reduction of obstacle shadows due to the hard palate, mandibular angle, and spine can be achieved. In this way, the incident of the X-ray beam on the subject M obliquely downward from above may be referred to as oblique upward irradiation.

[0036] Note that when performing panoramic X-ray imaging, it is not essential for the X-ray beam to be incident on the subject M obliquely downward from above with respect to the horizontal direction. For example, the X-ray beam may be incident along the horizontal direction with respect to the subject M.

[0037] The X-ray beam shaping unit may have other configurations. For example, the X-ray beam shaping unit may include two shielding members formed in an L-shaped plate form, and an opening may be formed by a combination of edges constituting the inner corner portions of the two shielding members. In this case, the two shielding members may be movable in the vertical and horizontal directions by an XY table mechanism or the like that can be driven to move in two orthogonal directions. When the two shielding members are driven to move by the mechanism, the shape of the opening is adjusted in the same manner as described above. Also, the X-ray beam shaping unit may have a configuration including a single shielding member in which one or more openings are formed. In this case, if the shielding member is driven to move by a linear movement mechanism, the position of the opening can be moved and the irradiation target of the X-ray beam can be moved. Also, a plurality of openings can be selectively opposed to the emission port of the X-ray generation unit 42.

[0038] As shown in FIGS. 1 and 2, the X-ray detection unit 44 includes an X-ray detector 45 and an X-ray detector vertical movement drive unit 47. The X-ray detector 45 detects the X-ray beam emitted from the X-ray generation unit 42. The X-ray detector 45 can be configured by a flat panel detector (FPD) having a detection surface that spreads in a planar shape, an X-ray image intensifier (I.I.), or the like.

[0039] A plurality of detection elements arranged on the detection surface of the X-ray detector 45 convert the intensity of the incident X-ray into an electrical signal. Then, the electrical signal is input as an output signal to the imaging control unit 100 and the image processing device 180, and an X-ray image is generated based on the signal.

[0040] In the present embodiment, the X-ray detection unit 44 includes a housing 46 that houses the X-ray detector 45. The X-ray detector 45 is provided inside the housing 46 in a posture where the detection surface faces the X-ray generation unit 42. The X-ray beam emitted from the X-ray generation unit 42 is irradiated onto the detection surface of the X-ray detector 45. The housing 46 is supported at the other end of the swing arm 40 in a state where the X-ray detector 45 and the X-ray detector vertical movement drive unit 47 are housed.

[0041] The X-ray detector vertical movement drive unit 47 moves the X-ray detector 45 in the vertical direction (Z-axis direction) with respect to the swivel arm 40. The X-ray detector vertical movement drive unit 47 includes a motor 47a, a ball screw 47b, and a nut portion 47c. The motor 47a rotates the ball screw 47b extending in the Z-axis direction about the Z-axis. The nut portion 47c is screwed onto the ball screw 47b and is non-rotatably attached to the back surface of the X-ray detector 45 on the side opposite to the detection surface of the X-ray detector 45. The X-ray detector 45 may be guided to move in the Z-axis direction in a posture facing the X-ray generation unit 42 side by a rail (not shown).

[0042] The motor 47a is controlled by the X-ray detector drive control unit 102e. Based on the control signal from the X-ray detector drive control unit 102e, when the motor 47a rotates the ball screw 47b, the nut portion 47c and the X-ray detector 45 are moved in the Z-axis direction.

[0043] The housing 46 includes a cylindrical portion 46a formed in a cylindrical shape that extends downward from the other end of the swivel arm 40 and opens downward, and an outer housing 46b that opens upward and covers the outside of the cylindrical portion 46a.

[0044] The motor 47a is fixed to the cylindrical portion 46a. The outer housing 46b is biased upward by a spring portion 46d provided to connect the swivel arm 40 or the cylindrical portion 46a and the outer housing 46b in the vertical direction. The lower end portion of the X-ray detector 45 can abut against the inside of the bottom surface of the outer housing 46b.

[0045] When the X-ray detector vertical movement drive unit 47 moves the X-ray detector 45 downward, the X-ray detector 45 hits the bottom surface of the outer housing 46b and pushes the outer housing 46b downward. At this time, the spring portion 46d elastically extends, and an elastic restoring force is accumulated in the spring portion 46d. Therefore, when the X-ray detector vertical movement drive unit 47 moves the X-ray detector 45 upward, the outer housing 46b is pulled upward by the elastic restoring force of the spring portion 46d. As a result, the outer housing 46b rises while coming into contact with and following the rising X-ray detector 45.

[0046] Note that the configuration for vertically moving the X-ray detection unit 44 with respect to the swing arm 40 may be omitted.

[0047] The outer housing 46b moves up and down with respect to the inner cylindrical portion 46a in accordance with the height position of the X-ray detector 45, so that the housing 46 expands and contracts in the vertical direction. By expanding and contracting the housing 46 in this way, the X-ray detector 45 whose position in the height direction changes can be appropriately protected. In addition, due to the spring portion 46d, the housing 46 can be arranged at the highest possible position, so that it is difficult for the housing 46 to come into contact with the subject M during X-ray imaging. That is, the cylindrical portion 46a, the outer housing 46b, the spring portion 46d, the X-ray detector vertical movement drive unit 47, and the X-ray detector 45 form an X-ray detection unit expansion and contraction mechanism that expands and contracts the X-ray detection unit 44 in the Z direction by guiding and driving the upward and downward movement of the bottom of the X-ray detection unit 44 and the X-ray detector 45 itself on the bottom side. The X-ray detection unit expansion and contraction mechanism can also function as an X-ray detection unit bottom position change mechanism that changes the Z-direction position of the bottom of the X-ray detection unit 44 and the X-ray detector 45 itself on the bottom side with respect to the swing arm 40.

[0048] In this embodiment, the lowermost end of the outer housing 46b (that is, the lowermost end of the housing 46) when the X-ray detector 45 is arranged at the highest position (that is, when the outer housing 46b is arranged at the highest position) may be configured to be lower than the lowermost end of the housing 41 of the X-ray generation unit 42. That is, in this case, regardless of the height at which the X-ray detector 45 is arranged, the lowermost end of the housing 46 is lower than the lowermost end of the housing 41.

[0049] When the X-ray beam is obliquely upward irradiated, the X-ray detector 45 can be positioned upward according to the position of the irradiation target. Thereby, when performing panoramic X-ray imaging by obliquely upward irradiation, the lower end of the outer housing 46b can be rotated at the highest possible position. Note that it is not essential to move the X-ray detection unit 44 and the housing 46 up and down according to the irradiation target of the X-ray beam. For example, when the detection surface of the X-ray detection unit 44 has a sufficiently large size to detect the X-ray beam regardless of the irradiation target of the X-ray beam, the X-ray detection unit 44 does not have to move up and down. Also, of course, when the irradiation direction of the X-ray beam does not vary vertically, the X-ray detection unit 44 and the housing 46 do not have to move up and down.

[0050] The swing arm 40 that supports the X-ray generation unit 42 and the X-ray detection unit 44 is supported by the upper frame 95 via the drive mechanism 60.

[0051] The upper frame 95 is supported by the support column 80. The support column 80 is supported in a standing state with respect to the floor by, for example, a base 80B that extends in a horizontal direction with respect to the floor. In the present embodiment, the base end portion of the upper frame 95 is supported by the support column 80 in a cantilever state, and the tip end portion of the upper frame 95 extends outward along the horizontal direction from the support column 80. A swing shaft portion 96 that extends in the Z-axis direction is provided at the tip end portion of the upper frame 95. The lower end portion of the swing shaft portion 96 is connected to an intermediate portion between the X-ray generation unit 42 and the X-ray detection unit 44 in the swing arm 40. Thereby, the swing arm 40 is supported in a suspended state by the upper frame 95 via the swing shaft portion 96.

[0052] The drive mechanism 60 is a device that drives the swing arm 40 so that the X-ray generation unit 42 and the X-ray detection unit 44 swing around the head P of the imaging subject M. The drive mechanism 60 can drive the swing arm 40 so as to change at least the swing orbit of the X-ray detection unit 44.

[0053] In this embodiment, the drive mechanism 60 includes a turning mechanism 62 and a turning axis moving mechanism 70 (hereinafter sometimes simply referred to as the axis moving mechanism 70). The turning mechanism 62 turns the turning arm 40 around the axis of the turning axis portion 96, that is, around the turning axis. The axis moving mechanism 70 moves the turning axis portion 96 in a direction intersecting (here, orthogonal) to the axial direction of the turning axis portion 96. The axis moving mechanism 70 is an example of a two-dimensional moving mechanism that moves the X-ray generating unit 42 and the X-ray detecting unit 44 in a two-dimensional direction (in this embodiment, the horizontal plane) along the turning plane of the X-ray generating unit 42 and the X-ray detecting unit 44 by the turning mechanism 62.

[0054] More specifically, as shown in FIG. 6, the turning arm 40 is rotatably supported around the central axis of the turning axis portion 96 with respect to the lower end portion of the turning axis portion 96. A bearing 97 may be interposed between the turning axis portion 96 and the turning arm 40 so that the turning arm 40 can rotate smoothly with respect to the turning axis portion 96.

[0055] The turning mechanism 62 is provided inside the turning arm 40. The turning mechanism 62 includes a turning motor 63. More specifically, the turning mechanism 62 includes a turning motor 63 fixed to the turning arm 40 and an endless annular belt 64. The rotation direction and rotation speed of the turning motor 63 are controlled by the support control unit 102a. The endless annular belt 64 is wound around an annular member (such as a pulley) fixed to the shaft of the turning motor 63 and an annular member for receiving driving force on the turning arm 40 side fixed to the lower end portion of the turning axis portion 96. In this case, the turning axis portion 96 is fixed so as not to rotate with respect to the upper frame 95. By transmitting a rotational force to the endless annular belt 64 by driving the turning motor 63, the turning motor 63 itself receives a reaction from the endless annular belt 64 and performs a rotational motion, and the turning arm 40 in a fixed relationship with the turning motor 63 rotates. The endless annular belt 64 may be an annular chain. One or more gears may be interposed between the turning motor 63 and the turning axis portion 96 instead of or in addition to the endless annular belt 64. The turning motor 63 may be directly connected to the turning axis portion 96.

[0056] Note that the turning mechanism 62 may be provided inside the upper frame 95. In this case, the turning shaft portion 96 that fixedly connects the turning shaft portion 96 and the turning arm 40 and is rotatably supported with respect to the upper frame 95 may be configured to rotate together with the turning arm 40.

[0057] The central axis X1 of the turning shaft portion 96 is located between the X-ray generation unit 42 on one end side of the turning arm 40 and the X-ray detection unit 44 on the other end side of the turning arm 40. For this reason, when the turning mechanism 62 rotates the turning arm 40, the X-ray generation unit 42 and the X-ray detection unit 44 can rotate around the central axis X1 of the turning shaft portion 96.

[0058] Note that in this embodiment, the imaging device 22 is provided on the turning arm 40. The imaging device 22 is provided at a position where the head P held by the subject holding unit 32 can be imaged. The imaging device 22 is, for example, a visible light camera. Here, the imaging device 22 is supported so as to face the X-ray generation unit 42 at the upper part of the housing 46 facing the X-ray generation unit 42 side. The imaging range by the imaging device 22 is set to, for example, a range including the head P and the shoulders S of the subject M held by the subject holding unit 32. Note that the imaging device 22 may be omitted. Later, a modified example using the imaging device 22 will be described.

[0059] As shown in FIGS. 5 and 6, the axial movement mechanism 70 is a mechanism that moves the turning shaft portion 96 in a direction intersecting (here, orthogonal) to the central axis of the turning shaft portion 96. In this embodiment, the turning shaft movement mechanism 70 is an XY direction movement mechanism that moves the turning shaft portion 96 in the X-axis direction and the Y-axis direction. The axial movement mechanism 70 includes, for example, an XY table 72 and drive motors 76a and 76b. The axial movement mechanism 70 is provided, for example, inside the upper frame 95.

[0060] The XY table 72 includes an X-direction movable table 73 and a Y-direction movable table 74. The X-direction movable table 73 is movably provided along the X direction and moves the swing arm 40 in the lateral direction (X-axis direction). The Y-direction movable table 74 is movably provided along the Y direction and moves the swing arm 40 in the front-rear direction (Y-axis direction). For example, the Y-direction movable table 74 is supported so as to be movable in the Y direction with respect to the upper frame 95, and the X-direction movable table 73 is supported so as to be movable in the X direction with respect to the Y-direction movable table 74. Then, as the Y-direction movable table 74 moves, the X-direction movable table 73, the swing shaft portion 96, and the swing arm 40 move along the Y direction. Also, as the X-direction movable table 73 moves, the swing shaft portion 96 and the swing arm 40 move along the X direction.

[0061] The driving motors 76a and 76b include an X-axis driving motor 76a that drives the X-direction movable table 73 and a Y-axis driving motor 76b that drives the Y-direction movable table 74. For example, a screw groove is formed on the rotating shaft of the X-axis driving motor 76a, and the rotating shaft is screwed into a screw hole provided in the X-direction movable table 73. In response to the forward or reverse rotational drive of the X-axis driving motor 76a, the X-direction movable table 73 moves in both directions along the X direction. The configuration in which the Y-axis driving motor 76b moves the Y-direction movable table 74 can also have a similar configuration. These X-axis driving motor 76a and Y-axis driving motor 76b are controlled by, for example, the support control unit 102a.

[0062] The X-direction movable table 73 and the Y-direction movable table 74 may be driven to move by other mechanisms such as a linear motor mechanism, a rack and pinion mechanism, a mechanism using a belt and a pulley. The axial movement mechanism 70 does not necessarily have to be an XY-direction movement mechanism and may be a multi-joint robot arm device.

[0063] Note that it is not essential for the drive mechanism 60 to include the axial movement mechanism 70 in addition to the turning mechanism 62. The drive mechanism 60 may be configured to turn the X-ray detector 45 around the turning axis at a fixed position by the turning mechanism 62.

[0064] In this embodiment, the axial movement mechanism 70 moves the turning shaft portion 96, the turning mechanism 62, and the turning arm 40 in the X-axis direction and the Y-axis direction. Therefore, during the turning of the turning arm 40 by the turning mechanism 62, the mechanical turning axis X1 (the central axis of the turning shaft portion 96) of the turning arm 40 can be moved along the XY direction. Thereby, the X-ray detection unit 44 and the X-ray generation unit 42 can perform a combined movement of the turning movement by the turning mechanism 62 and the axial movement by the axial movement mechanism 70. By adjusting the movement path of the turning shaft portion 96 by the axial movement mechanism 70, the turning orbit of the X-ray detection unit 44 and the X-ray generation unit 42 can be set.

[0065] Note that the turning axis movement mechanism may be provided on the turning arm side. In this case, the lower end of the turning shaft portion 96 fixed at a fixed position in the XY plane of the upper frame 95 is supported by the turning axis movement mechanism provided on the turning arm side. Then, by the turning axis movement mechanism moving the turning shaft portion 96 relative to the turning arm 40 in the XY direction, the turning arm can move in the XY direction with respect to the turning shaft portion 96 at a fixed position.

[0066] It is not essential for the drive mechanism 60 to include the axial movement mechanism 70. For example, instead of providing the axial movement mechanism 70, the end of the swivel arm 40 on the X-ray detector unit 44 side may be configured to be telescopically drivable along the longitudinal direction of the swivel arm 40 by a telescopic mechanism such as a linear motor or a rack and pinion mechanism. In this case, by telescopically driving the swivel arm 40, the X-ray detector unit 44 can move in a two-dimensional direction along the swivel plane of the X-ray detector unit 44 or the like, and thus the swivel orbit of the X-ray detector unit 44 can be changed. Further, the X-ray detector unit 44 may be configured to be movable closer to and farther from the X-ray generator unit 42 by a movable support mechanism such as a linear motor or a rack and pinion mechanism at the end of the swivel arm 40. In this case, by moving the X-ray detector unit 44 closer to and farther from the X-ray generator unit 42 by the movable support mechanism, the swivel orbit of the X-ray detector unit 44 can be changed.

[0067] Note that the two-dimensional movement mechanism does not necessarily have to be the axial movement mechanism 70. For example, the end of the swivel arm 40 on the X-ray detector unit 44 side may be configured to be telescopically drivable along the longitudinal direction of the swivel arm 40 by a telescopic mechanism such as a linear motor or a rack and pinion mechanism. In this case, by telescopically driving the swivel arm 40, the X-ray detector unit 44 can move in a two-dimensional direction along the swivel plane of the X-ray detector unit 44 or the like. Further, the X-ray detector unit 44 may be configured to be movable closer to and farther from the X-ray generator unit 42 by a movable support mechanism such as a linear motor or a rack and pinion mechanism at the end of the swivel arm 40. In this case, by the movable support mechanism, the X-ray detector unit 44 can move in a two-dimensional direction along the swivel plane of the X-ray detector unit 44 or the like.

[0068] The vertical drive unit 82 is an example of a displacement mechanism. More specifically, the vertical drive unit 82 is an example of a vertical displacement mechanism that vertically displaces the X-ray detector unit 44 with respect to the head P. The vertical drive unit 82, which is a vertical displacement mechanism, may also be expressed as an example of a displacement mechanism that adds vertical movement to the X-ray detector unit 44. Further, the vertical drive unit 82 may also be expressed as an example of a displacement mechanism that adds movement including a vertical displacement component to the X-ray detector unit 44. In the present embodiment, the vertical drive unit 82 vertically moves the swivel arm 40 with respect to the head P. By the vertical movement of the swivel arm 40, the X-ray detector 45 can move vertically together with the X-ray generation unit 42.

[0069] More specifically, the vertical drive unit 82 drives the swivel arm 40 to move up and down with respect to the support column 80. More specifically, as shown in FIGS. 1 and 2, an upper frame 95 is supported by the support column 80 so as to be movable up and down. A vertical drive unit 82 for moving the upper frame 95 up and down along the Z-axis direction is provided on the support column 80. The vertical drive unit 82 is a mechanism that drives the upper frame 95 to move up and down with respect to the support column 80. The vertical drive unit 82 includes, for example, a motor 83, a ball screw 84, a nut portion 85, and a plurality (here, four) of roller portions 86.

[0070] The base end portion of the upper frame 95 surrounds a part of the support column 80 in the vertical direction. The roller portion 86 is provided at the base end portion of the upper frame 95. The roller portion 86 is supported within the base end portion of the upper frame 95 so as to be able to travel along a rail 80r extending in the Z-axis direction provided on the surface of the support column 80. Thereby, the upper frame 95 is supported by the support column 80 so as to be movable up and down. At this time, as the roller portion 86 moves along the rail, rotation of the upper frame 95 around the Z-axis with respect to the support column 80 is suppressed. When considering the vertical drive unit 82 to also include an element that guides the movement direction of the upper frame 95, it may be considered that the vertical drive unit 82 includes the motor 83, the ball screw 84, the nut portion 85, the roller portion 86, and the rail 80r.

[0071] The motor 83 is supported at a fixed position with respect to the support column 80. In the example shown in FIG. 2, the motor 83 is provided at the lower part of the support column 80. The motor 83 rotates a ball screw 84 extending in the Z-axis direction about the Z-axis. The nut portion 85 is supported within the base end portion of the upper frame 95, and the ball screw 84 is screwed into the nut portion 85. The nut portion 85 is fixed to the base end portion of the upper frame 95 so as not to rotate. Then, in response to the forward or reverse rotation of the motor 83, as the ball screw 84 rotates, the nut portion 85 moves upward or downward. Along with the movement of the nut portion 85, the upper frame 95 moves up and down in the Z-axis direction. As a result, the swing arm 40 and the X-ray generation unit 42 and the X-ray detection unit 44 supported by the swing arm 40 move up and down along the Z-axis direction.

[0072] Note that the displacement mechanism does not need to move the X-ray detection unit 44 up and down together with the swivel arm 40. For example, a vertical drive unit for raising and lowering the entire swivel arm 40 during X-ray imaging of the head P may be omitted, and only the X-ray detection unit may be vertically displaced. More specifically, the X-ray detector 45 and the outer housing 46b are the X-ray detection unit, and an X-ray detector vertical movement drive unit 47 for moving the X-ray detector 45 and the outer housing 46b up and down may be regarded as the displacement mechanism. In this case, for example, during the rotation of the X-ray detection unit 44, the X-ray detector vertical movement drive unit 47 may move the X-ray detection unit including the X-ray detector 45 and the outer housing 46b up and down. Thereby, the X-ray detector vertical movement drive unit 47 can also add a movement different from the rotation of the X-ray detector 45 to the X-ray detection unit including the X-ray detector 45 and the outer housing 46b, particularly a vertical movement orthogonal to the rotation plane. In this case, the X-ray detector vertical movement drive unit 47 can function as the vertical drive unit 82. According to the vertical movement of the X-ray detector 45 by the X-ray detector vertical movement drive unit 47, the X-ray beam shape adjustment unit 50 may adjust the irradiation direction of the X-ray beam so that the X-ray beam irradiates the X-ray detector 45. As an example of using the X-ray detector vertical movement drive unit 47 for the retraction of the X-ray detection unit 44 in the +Z direction, a state where the X-ray detector 45 abuts against the bottom surface of the outer housing 46b and pushes down the outer housing 46b may be set as the normal state, and the X-ray detection unit 44 may be retracted in the +Z direction by moving the X-ray detector 45 in the +Z direction to avoid contact with the shoulder S.

[0073] The displacement mechanism imparts vertical movement to the outer housing 46b. Here, vertical movement means a movement that causes a change in position in the vertical direction (z direction). Therefore, for example, the vertical movement of the outer housing 46b includes any orbit that causes a change in position in the vertical direction, such as movement along the vertical straight orbit of the outer housing 46b, movement along other straight orbits, movement along a curved orbit, and an orbit along an oblique orbit.

[0074] The subject holding unit 32 is a member that holds the subject to be photographed M (head P). In the present embodiment, the subject holding unit 32 includes an anterior tooth region fixing unit that fixes the anterior tooth region Pa in the head P. More specifically, the subject holding unit 32 includes a chin rest 33, a head holder 34 (see FIG. 1), and a lower frame 35.

[0075] The chin rest 33 fixes the anterior tooth region Pa in a fixed position by supporting the tip of the lower jaw of the head P. Here, the anterior tooth region Pa refers to the region of the head P that includes the anterior teeth and the base that supports the anterior teeth. For example, it is the anterior teeth themselves and the lower jaw (especially the tip of the jaw). That is, the chin rest is an example of the anterior tooth region fixing unit. The anterior tooth region fixing unit does not have to be a chin rest, and may be, for example, a bite piece that is bitten by the upper and lower anterior teeth.

[0076] The head holder 34 positions the head P in the X-axis direction by sandwiching the head P from both sides. In the subject holding unit 32, the anterior tooth region fixing unit or the head holder 34 may be omitted.

[0077] The base end portion of the lower frame 35 is supported by the support column portion 80 in a cantilevered manner, and the tip end portion of the lower frame 35 extends along the horizontal direction from the support column portion 80. The chin rest 33 and the head holder 34 are supported at the tip end portion of the lower frame 35. The chin rest 33 and the head holder 34 are supported so as to face between the X-ray generating unit 42 and the X-ray detecting unit 44 supported by the swing arm 40. The head P supported by the subject holding unit 32 is held at a fixed position between the X-ray generating unit 42 and the X-ray detecting unit 44 during the swing of the X-ray generating unit 42 and the X-ray detecting unit 44.

[0078] The subject holding unit 32 is driven to move up and down by the holding unit driving unit 36. That is, the base end portion of the lower frame 35 is supported by the support column portion 80 so as to be movable in the Z-axis direction. The lower frame 35 is driven to move up and down in the Z-axis direction by the driving of the holding unit driving unit 36.

[0079] The holding part driving part 36 includes a motor 36a, a ball screw 36b, a nut part 36c, and a plurality (here, four) of roller parts 36d. The base end part of the lower frame 35 surrounds a part of the upper and lower directions of the support column part 80. The roller part 36d is provided inside the base end part of the lower frame 35. The roller part 36d is fixed inside the lower frame 35 so that it can travel along a rail 80r extending in the Z-axis direction provided on the support column part 80. Thereby, the lower frame 35 is supported so as to be movable up and down along the support column part 80. At this time, as the roller part 36d moves along the rail, the rotation of the lower frame 35 around the Z-axis with respect to the support column part 80 is suppressed. When considering the holding part driving part 36 including elements for guiding the moving direction of the lower frame 35, it may be considered that the holding part driving part 36 includes the motor 36a, the ball screw 36b, the nut part 36c, the roller part 36d, and the rail 80r.

[0080] The motor 36a rotates the ball screw 36b extending in the Z-axis direction around the Z-axis. Here, the motor 36a is supported by the base end part of the lower frame 35, the ball screw 36b extends upward from the base end part of the lower frame 35, and reaches the base end part of the upper frame 95.

[0081] The nut part 36c is supported by the base end part of the upper frame 95. The nut part 36c is fixed to the base end part of the upper frame 95 so as not to rotate. The ball screw 36b reaching the base end part of the upper frame 95 is screwed into the nut part 36c.

[0082] According to the forward or reverse rotation of the motor 36a, the ball screw 36b rotates, and according to the rotation, the lower frame 35 can move up and down with respect to the nut part 36c into which the ball screw 36b is screwed. When the lower frame 35 moves up and down, the chin rest 33 and the head holder 34 supported by the lower frame 35 can also move up and down. Therefore, the vertical holding position of the head P by the subject holding part 32 and the vertical position of the X-ray imaging region by the X-ray generating part 42 and the X-ray detecting part 44 can be adjusted synchronously or separately.

[0083] For example, while maintaining the holding height of the head P by the subject holding unit 32 at a constant level, the irradiation position of the X-ray on the head P can be changed in the Z-axis direction by relatively raising and lowering the swing arm 40 with respect to the head P. Specifically, in accordance with the actual position of the head P, the swing arm 40 and the subject holding unit 32 are raised and lowered by the vertical drive unit 82 while keeping the lower frame 35 from being raised and lowered with respect to the upper frame 95 by the holding unit drive unit 36, and the head P is held by the chin rest 33 and the head holder 34. Thereafter, the swing arm 40 is raised by the vertical drive unit 82, and the subject holding unit 32 is relatively lowered with respect to the swing arm 40 by the holding unit drive unit 36 so as to keep the subject holding unit 32 at a constant height position. Alternatively, the swing arm 40 is lowered by the vertical drive unit 82, and the subject holding unit 32 is relatively raised with respect to the swing arm 40 by the holding unit drive unit 36 so as to keep the subject holding unit 32 at a constant height position.

[0084] Further, the upper frame 95 and the lower frame 35 are connected via a ball screw 36b. For this reason, the swing arm 40 and the subject holding unit 32 are integrally raised and lowered by the vertical drive unit 82.

[0085] The upper frame 95 is also an imager supporter that supports an imager including an X-ray generating unit 42 and an X-ray detecting unit 44. The lower frame 35 is also a subject supporter that supports a subject holder called a subject holding unit 32. The upper frame 95 and the lower frame 35 are an imaging supporter of the imager supporter-subject supporter connection type that are connected by a ball screw 36b. The vertical drive unit 82 is also an imager elevator that raises and lowers at least the imager supporter. The holding unit drive unit 36 is also a subject elevator that raises and lowers the subject supporter. The holding unit drive unit 36 is also an imager-subject distance adjuster that adjusts the distance between the imager supporter and the subject supporter. The vertical drive unit 82 raises and lowers the imaging supporter, and the distance between the imager supporter and the subject supporter that constitute the imaging supporter is adjusted by the imager-subject distance adjuster.

[0086] The holding unit drive unit 36 may not be provided, and the vertical drive unit 82 may be configured to raise and lower only the imager supporter, and the subject supporter may be raised and lowered by another vertical drive unit independent of the vertical drive unit 82. In this case, the vertical drive unit 82 can also function as an imager-subject distance adjuster by raising and lowering the imager supporter.

[0087] In any case, the X-ray imaging apparatus 20 includes an imager elevator and an imager-subject distance adjuster with respect to raising and lowering in the Z direction.

[0088] The imaging control unit 100 controls the X-ray imaging operation of the imaging main body unit 30 and is a kind of computer device. In the present embodiment, the imaging control unit 100 can function as a turning control unit that controls the turning operation of the turning arm 40 by the drive mechanism 60 and the additional movement operation by the vertical drive unit 82 during panoramic X-ray imaging. In addition to controlling the operation of the turning arm 40, the imaging control unit 100 may be configured to enable various other controls. For example, it may control the operation of the operation display unit 110 to perform reception control of operations and display control.

[0089] FIG. 7 is a block diagram showing an example of the electrical configuration of the X-ray imaging apparatus 20. The imaging control unit 100 includes, for example, at least one processor 102 and a storage unit 104.

[0090] The storage unit 104 is constituted by a non-volatile storage device such as a flash memory or a hard disk drive, for example. The storage unit 104 stores a shooting program 104a that receives various instructions related to X-ray imaging and controls the X-ray imaging operation by controlling the turning mechanism 62, the axial movement mechanism 70, the vertical drive unit 82, the holding unit drive unit 36, the X-ray generator 43, the X-ray beam shape adjustment unit 50, etc. according to the various instructions. Further, vertical displacement information 104b is stored in the storage unit 104. The vertical displacement information 104b is information for setting the vertical displacement operation of the X-ray detection unit 44 during panoramic X-ray imaging.

[0091] Let the trajectory of the movement of the X-ray detection unit 44 during X-ray imaging be the X-ray detection trajectory DTL. Let the trajectory of the X-ray detection unit 44 on the XY plane by the drive mechanism 60 be the horizontal trajectory HZL, and the trajectory of the turning of the X-ray detection unit 44 on the XY plane be the horizontal turning trajectory HRL. Let the trajectory of the vertical movement of the X-ray detection unit 44 by the vertical drive unit 82 be the elevating trajectory ELL. When X-ray imaging with vertical displacement accompanying the horizontal turning of the X-ray detection unit 44 is performed, the X-ray detection trajectory DTL is a combined trajectory of the horizontal turning trajectory HRL and the elevating trajectory ELL. Such a combined trajectory may be called a turning and elevating trajectory REL.

[0092] The X-ray detection trajectory DTL of the X-ray detection unit 44 during panoramic X-ray imaging may be a turning and elevating trajectory REL. The turning and elevating trajectory REL may include the case where the amount of vertical displacement movement of the X-ray detection unit 44 is zero. Let the information defining the horizontal trajectory HZL of the X-ray detection unit 44 be the horizontal movement information HZI, and the information defining the horizontal turning trajectory HRL of the X-ray detection unit 44 be the horizontal turning movement information HRI. Let the information defining the elevating trajectory ELL of the X-ray detection unit 44 be the elevating information ELI. The vertical displacement information 104b is an example of the elevating information ELI. The case where the displacement amount of the vertical movement of the X-ray detection unit 44 is zero may be included in this elevating information ELI.

[0093] During panoramic X-ray imaging, the movement of the X-ray detector unit 44 is a movement in which the vertical movement by the vertical drive unit 82 is added to the turning operation of the X-ray detector unit 44 by the turning mechanism 62. The vertical displacement information 104b is information that associates, for example, the turning operation of the X-ray detector unit 44 by the drive mechanism 60 with the vertical movement operation of the X-ray detector 45 by the vertical drive unit 82 with respect to the turning operation.

[0094] The support control unit 102a controls the drive mechanism 60 and the vertical drive unit 82 based on the vertical displacement information 104b and the horizontal turning movement information HRI, so that during the turning of the X-ray detector 45, the movement by the vertical drive unit 82 can be added to the X-ray detector 45.

[0095] Note that the movement of the X-ray detector unit 44 may be a combined movement of the turning operation of the X-ray detector unit 44 by the turning mechanism 62 and the movement operation of the turning axis portion 96 by the axis movement mechanism 70 during the turning by the turning mechanism 62. Thereby, the turning orbit of the X-ray detector 45 can be made into a non-circular orbit or the size of the orbit can be changed. An example in the case of changing the turning orbit will be described later.

[0096] The processor 102 is constituted by a CPU (Central Processing Unit) or the like. By the processor 102 executing the imaging program 104a, various functions of the processor 102 are realized. The processor 102 is constituted by a circuit and includes, as functional blocks realized by the execution of the imaging program 104a, for example, a support control unit 102a, a vertical displacement setting unit 102b, an X-ray detector unit drive control unit 102e, a detection signal processing unit 102f, a holding unit control unit 102c, and an irradiation control unit 102d. That is, the processor 102 is constituted by a circuit that executes the imaging program 104a to perform, for example, support control, vertical displacement setting, drive control of the X-ray detector unit, processing of detection signals, holding unit control, and irradiation control.

[0097] The support control unit 102a controls the turning operation of the turning arm 40 by the turning mechanism 62 and the axial movement mechanism 70 so that the X-ray generation unit 42 and the X-ray detection unit 44 perform panoramic imaging while the head P of the subject M held by the subject holding unit 32 is positioned between them and rotating around the head P.

[0098] The support control unit 102a may control the operation of the vertical drive unit 82 to perform lifting control of the turning arm 40.

[0099] The vertical displacement setting unit 102b sets the vertical movement of the X-ray detector 45 during the turning of the X-ray detector 45 during panoramic X-ray imaging. The vertical movement of the X-ray detector 45 is a movement to avoid contact with the shoulder S of the subject M.

[0100] The X-ray detection unit drive control unit 102e controls the X-ray detector vertical movement drive unit 47 to adjust the vertical position of the X-ray detection unit 44. In this embodiment, it is assumed that the adjustment of the vertical position of the X-ray detector 45 by the X-ray detector vertical movement drive unit 47 is performed before performing panoramic X-ray imaging.

[0101] The detection signal processing unit 102f generates X-ray imaging data suitable for generating a panoramic X-ray image or the like based on the electrical signal from the X-ray detector 45. The X-ray imaging data is supplied to the image processing device 180.

[0102] The holding unit control unit 102c may control the holding unit drive unit 36 to control the height position of the subject holding unit 32.

[0103] The irradiation control unit 102d controls the X-ray generator 43 and the X-ray beam shape adjustment unit 50. For example, when performing panoramic X-ray imaging, the X-ray beam shape adjustment unit 50 is controlled to form the X-ray beam into an X-ray slit beam. Also, when performing panoramic X-ray imaging and when performing uplift irradiation, the X-ray beam shape adjustment unit 50 is controlled according to the uplift angle. According to this uplift angle, it is preferable that the vertical movement drive unit 47 of the X-ray detector also adjusts the vertical position of the X-ray detection unit 44. Further, the irradiation control unit 102d can control the presence or absence of X-ray emission and the intensity of the X-ray by controlling at least one of the voltage and current supplied to the X-ray tube of the X-ray generator 43.

[0104] Here, the operation of the imaging control unit 100 when performing panoramic X-ray imaging will be mainly described. However, when the imaging control unit 100 performs other X-ray CT imaging or cephalo imaging, it also controls each part of the X-ray imaging apparatus 20 and executes various processes based on the electrical signals from the X-ray detector 45.

[0105] The imaging control unit 100 is connected to the operation display unit 110. The operation display unit 110 includes a display device for displaying various information and various information (including imaging conditions, etc.) and an information input device for inputting commands to the imaging control unit 100. The display device is realized by a liquid crystal display device, an organic EL (Electroluminescent) display device, etc. The information input device can be realized by a switch, a pointer, a touch detection device of a touch panel, etc. Such an operation display unit 110 may be configured by, for example, a touch panel display device in which a touch detection device is incorporated in the display surface of the display device. The operation display unit 110 may have a configuration in which the display device and the information input device are separate. The operation display unit 110 may be provided at any part of the present X-ray imaging apparatus 20 (for example, the column part 80, the housing 46, etc.), or may be provided at a location separate from the X-ray imaging apparatus 20 (for example, the outer wall surface of the X-ray shielding room, another table). The operation display unit 110 can function as a imaging setting reception unit 110a.

[0106] The imaging control unit 100 is connected to the image processing apparatus 180 via the communication interface 108. The image processing apparatus 180 is a kind of computer device. The image processing apparatus 180 generates X-ray image data, particularly X-ray panoramic image data, based on the X-ray imaging data from the imaging control unit 100. The X-ray image processing apparatus 180 includes, for example, a control unit 182, a storage unit 183, an image processing unit 184, an operation unit 185, a display unit 186, and the like. The storage unit 183 is a non-volatile storage device such as a flash memory or an HDD, and stores a control program, X-ray imaging data, X-ray image data, and the like. The control unit 182 includes at least one processor, and by operating according to the control program stored in the storage unit 183, the control unit 182 executes a process of generating X-ray image data (particularly, X-ray panoramic imaging data) based on the X-ray imaging data transmitted from the imaging control unit 100. For example, when panoramic imaging is performed by the X-ray imaging apparatus 20, the imaging control unit 100 performs an arithmetic process of acquiring a panoramic image that images the target tomographic layer. Specifically, the imaging control unit 100 performs a shift addition process of mutually shifting and adding pixel values to a plurality of strip-shaped X-ray projection images acquired by the imaging main body unit 30 according to the position on the tomographic layer, thereby acquiring one panoramic X-ray image.

[0107] FIG. 7 shows an image processing unit realized by a processor for image processing. The process of generating X-ray image data may be realized by a general-purpose processor included in the imaging control unit 100, may be realized by a processor for image processing, or may be realized by the cooperation of these processors. The generated X-ray image data may be stored in the storage unit 183, or may be stored in another storage device, for example, the storage device of the imaging control unit 100 or the storage device of the server.

[0108] The operation unit 185 is an input device for inputting various information and support to the image processing apparatus 180, and can be realized by a switch, a pointer, a touch detection device of a touch panel, or the like.

[0109] The display unit 186 is realized by a liquid crystal display device, an organic EL (Electroluminescent) display device, or the like. The panoramic X-ray image generated by the image processing device 180 may be displayed on the display unit 186 (see FIG. 1).

[0110] Note that some or all of the functions realized in each of the above units may be realized hardware-wise by a dedicated logic circuit or the like. Also, some or all of the functions realized in each of the above units may be integrated and processed by one processor, or may be appropriately distributed and processed by a plurality of processors.

[0111] The storage unit 104 stores drive information 104DR (support unit drive information 104DR) for the movement of the swing arm 40, which is a support unit in X-ray imaging. The drive information 104DR includes, for example, drive information 104DRP for panoramic X-ray imaging, drive information 104DRC for X-ray CT imaging, and the like. If the drive information 104DR ultimately determines the trajectory of the X-ray detection unit 44 in X-ray imaging, the drive information 104DR is also information for determining the trajectory of the X-ray detection unit 44. If the drive information 104DR ultimately determines the trajectory of the X-ray generation unit 42 in X-ray imaging, the drive information 104DR is also information for determining the trajectory of the X-ray generation unit 42. In the drive information 104DR, the element that determines the trajectory of the X-ray detection unit 44 may be considered as X-ray detection trajectory information 104DT, and the element that determines the trajectory of the X-ray generation unit 42 may be considered as X-ray generation trajectory information 104GN. Considering the combination of the X-ray generation unit 42 and the X-ray detection unit 44 as an imager, since the drive information 104DR determines the trajectory of the X-ray generation unit 42 and the X-ray detection unit 44, that is, the trajectory of the imager, it may be considered as imager trajectory information 104E. It may be considered that the X-ray detection trajectory information 104DT in the drive information 104DRP includes vertical displacement information 104b and horizontal swing movement information HRI.

[0112] <Operation of the X-ray imaging apparatus> The operation of the X-ray imaging apparatus will be described with a focus on panoramic X-ray imaging. The following operations are performed under the control of the imaging control unit 100, particularly the processor 102. FIG. 8 is a flowchart showing an example of the process related to panoramic X-ray imaging.

[0113] When the X-ray imaging apparatus 20 is activated, power is supplied to each part, and the imaging main body 30, the imaging control unit 100, and the image processing apparatus 180 enter the standby state. Then, on the operation display unit 110, a setting screen for the imaging mode is displayed. The setting screen for the imaging mode is, for example, a screen for selecting one mode from among a panoramic X-ray imaging mode, an X-ray CT imaging mode, etc. By selecting the panoramic X-ray imaging mode through a touch operation or the like on the operation display unit 110, the panoramic imaging mode process is started.

[0114] Note that when performing panoramic X-ray imaging, the height of the swing arm 40 and the subject holding unit 32 is adjusted according to the height position of the head P of the subject M to be imaged. The height adjustment may be performed by the operator inputting an instruction to raise or lower the swing arm 40 and the subject holding unit 32 through the operation display unit 110 or the like.

[0115] The arrangement in the Z direction between the subject holding unit 32 with normal settings and the upper frame 95, that is, the relationship between their heights, may be set to adapt to the shape of a standard head P before panoramic X-ray imaging. When the lower jaw is longer than that of a standard head P, corresponding measures may be taken according to the individual skeleton, such as increasing the distance in the Z direction between the upper frame 95 and the subject holding unit 32 by the above-described imager subject distance adjuster and then starting X-ray imaging.

[0116] When the panoramic imaging mode process is started, in step S1, no vertical displacement is initially set. For this reason, when there is no special instruction regarding vertical displacement, the X-ray detection unit 44 rotates without vertical displacement to perform panoramic X-ray imaging.

[0117] Note that the imaging trajectory of the X-ray detector 45 during X-ray CT imaging may be a trajectory centered on the rotation axis X1 at a fixed position. That is, without moving the swivel shaft portion 96 by the shaft movement mechanism 70 (with the swivel shaft portion 96 stationary), the swivel arm 40 may be swiveled by the swivel mechanism 62 to perform X-ray CT imaging.

[0118] The imaging trajectory of the X-ray detector 45 during panoramic X-ray imaging may be a trajectory centered on the moving rotation axis X1. That is, while moving the swivel shaft portion 96 by the shaft movement mechanism 70, the swivel arm 40 may be swiveled by the swivel mechanism 62 to perform panoramic X-ray imaging. For example, an example of the swivel trajectory R is shown in FIG. 9. The shape of the head P is shown in FIG. 9. It is assumed that the shape of the shoulder S is standard.

[0119] The swivel trajectory R is an arc-shaped line along the outer peripheral side of the dental arch Arc. The swivel trajectory may be set to a range capable of detecting X-rays that have passed through the anterior teeth and molars in the dental arch, and further, a region including the temporomandibular joint to the vicinity of the mandibular angle. From this perspective, the swivel trajectory R may be an arc-shaped trajectory in a range exceeding 90° to the left and right (for example, a range of ±115°) centered on the front portion at the center in the left-right direction of the head P. The swivel trajectory R is an example of the horizontal swivel trajectory HRL.

[0120] The center of the head P is defined as the head center HC, and among the head surfaces, the point where the X-ray slit beam passes is defined as the point IP. There are various ways to define the head center HC. For example, it can be considered as the intersection of the front-back center and the left-right center. In the Z-direction view, the direction in which the X-ray travels at the point IP and the direction parallel to this direction are called the forward irradiation direction, and the opposite direction of the forward irradiation direction is called the reverse irradiation direction. Since the distance between the head center HC and the point IP varies depending on the position of the point IP due to the change in the irradiation direction, it is necessary to move the X-ray detection unit 44 and the pivot shaft unit 96 to cope with this change. This movement amount is considered as an offset value, and the relationship between the movement purely according to the distance between the X-ray detection unit 44 and the surface of the head P and the movement of the pivot shaft unit 96 is considered. In the case of this embodiment, the turning orbit R is an orbit that moves the X-ray detection unit 44 away from the surface of the head P on the side of the head P and moves the X-ray detection unit 44 closer to the surface of the head P in front of the head P. That is, the distance of the X-ray detection unit 44 from the surface of the head P is small in the front and large on the side. Such an orbit may be referred to as a forward approach orbit FC. Thus, the turning orbit R may be set to be the forward approach orbit FC. To move the X-ray detection unit 44 along the above-mentioned turning orbit R, when the X-ray detection unit 44 turns around the pivot shaft unit 96, the pivot shaft unit 96 is moved by the axial movement mechanism 70. For example, the position of the pivot shaft unit 96 may be adjusted according to the distance of the turning orbit R from the surface of the head P. For example, in the portion of the turning orbit R that approaches the surface of the head P (in front of the head P), the movement closer to the surface is realized by the movement of the pivot shaft unit 96 in the reverse irradiation direction, and in the portion of the turning orbit R that moves away from the surface of the head P (on the side of the head P), the movement away from the surface is realized by the movement of the pivot shaft unit 96 in the forward irradiation direction.

[0121] In this case, it is preferable that the turning orbit information 204 for defining the turning orbit is stored in the storage unit 104. The turning orbit information 204 is an example of the horizontal turning movement information HRI. For example, it is information that determines the position of the turning axis X1 in the turning operation of the X-ray detection unit 44. When the imaging control unit 100 controls the turning operation of the X-ray detection unit 44 by the turning mechanism 62, based on the turning orbit information 204, the turning axis portion 96 is moved by the axis movement mechanism 70, so that the X-ray detection unit 44 can move along the turning orbit R. The turning orbit information 204 may be arbitrarily set by the user. The user may also be able to change the turning orbit information 204 stored in the storage unit 104 to set new turning orbit information 204.

[0122] The turning orbit R may be set to pass through a position within 10 cm from the surface of the head P in front of the head P. The turning orbit R may also be set to pass through a position within 10 cm from the surface of the head P over the entire circumference of the head P.

[0123] Regarding the arrangement of the X-ray detection unit 44, when the distance AD between the X-ray detection unit 44 and the surface of the head P (point IP) in a certain arrangement AA is smaller than the distance BD between the X-ray detection unit 44 and the surface of the head P in another arrangement BA, in the comparison between the arrangement AA and the arrangement BA, the state of the arrangement AA shall be expressed as "high proximity", and the state of the arrangement BA shall be expressed as "low proximity".

[0124] Let the distance between the X-ray detection unit 44 and the surface of the head P (point IP) when the X-ray detection unit 44 is in front of the head P be the distance FD, and the distance between the X-ray detection unit 44 and the surface of the head P (point IP) when the X-ray detection unit 44 is on the side of the head P be the distance SD. Let the value of the distance FD / distance SD be the proximity separation ratio FSR. The fact that the proximity separation ratio FSR is smaller shall be expressed as "high front proximity ratio" and "low side proximity ratio", and the fact that the proximity separation ratio FSR is larger shall be expressed as "low front proximity ratio" and "high side proximity ratio". Compared with a turning orbit in which the distance FD and the distance SD are equal, the turning orbit R of the present embodiment has a high front proximity ratio.

[0125] The distance to the front surface of the front part of the head P (at least in the center in the left - right direction of the head P) can be expressed as the separation distance of the trajectory with respect to the center in the left - right direction of the front part of the head. The above - mentioned distance to the side surface of the head P on the side of the head P (at least in the left - right direction in the center in the front - rear direction of the head P) can also be expressed as the separation distance of the trajectory with respect to the center in the front - rear direction of the side part of the head.

[0126] In step S2 after step S1, it is confirmed whether there is a setting change in the vertical displacement amount. The setting change of the vertical displacement amount is made, for example, through the operation display unit 110. For example, an icon for setting the vertical displacement amount is displayed on the operation display unit 110, and by touching the icon, a setting change of the vertical displacement amount is accepted. When it is determined that there is a setting change in the vertical displacement amount, the process proceeds to step S3. When it is determined that there is no setting change, step S3 is skipped and the process proceeds to step S4.

[0127] In step S3, based on the set vertical displacement amount, a vertical displacement pattern is set.

[0128] Here, an example of setting the vertical displacement amount will be described. For example, as shown in FIG. 16, the vertical displacement information 104b includes a vertical displacement pattern 104b1 in which the height information of the X-ray detection unit 44 is associated with the turning angle of the X-ray detection unit 44 during panoramic X-ray imaging. The data of the vertical displacement pattern 104b1 may be expressed by a data sequence or may be expressed by an equation with the turning angle as a variable. When the initial position of the turning angle is set as the front position of the center in the left-right direction (X direction) of the head P, the clockwise direction from the initial position is the + direction, and the counterclockwise direction is the - direction, the height is the smallest at the turning angle of 0°, and the height is the largest at the turning angles of ±90°. At the turning angle (for example, ±90°) where the X-ray detection unit 44 is located on the side of the head P, the height hm [mm] of the X-ray detection unit 44 is set to exceed the height hs [mm] of the shoulder S. In other words, the vertical displacement pattern 104b1 determines the position of the X-ray detection unit 44 during the turning of the X-ray detection unit 44 such that the lower end position of the X-ray detection unit 44 passing through the side of the head P is located above the lower end position of the X-ray detection unit 44 passing through the front of the head P. The imaging control unit 100 controls the driving to add vertical movement to the X-ray detection unit 44 by the vertical driving unit 82 along the vertical displacement pattern 104b1. The vertical driving unit 82 functions as a mechanism for vertically moving the turning arm 40 relative to the head P. At the turning angle (for example, ±90°) where the X-ray detection unit 44 is located on the side of the head P, the height hm [mm] of the X-ray detection unit 44 is set to exceed the height hs [mm] of the shoulder S. Between the turning angle of 0° and the turning angles of ±90°, the height is set to change smoothly while drawing a curve. In the range where the turning angle exceeds the turning angles of ±90°, the height at the turning angles of ±90° may be maintained, or the height may change to decrease. The imaging control unit 100 may adjust the height position of the X-ray detection unit 44 with the height position of the initially positioned X-ray detection unit 44 as the height at the turning angle of 0°.

[0129] The vertical displacement information 104b may include only one vertical displacement pattern 104b1. In this case, in step S2, a setting for whether to perform vertical displacement is input, and in step S3, the one vertical displacement pattern 104b1 is set as the vertical displacement pattern.

[0130] The vertical displacement information 104b may include a plurality of vertical displacement patterns 104b1, 104b2, 104b3. The plurality of vertical displacement patterns 104b1, 104b2, 104b3 have different height differences from each other. The vertical displacement patterns 104b1, 104b2, 104b3 may be considered as examples of lifting information regarding the vertical movement of the X-ray detection unit 44. In FIG. 10, at the positions of the turning angles of ±90°, the height of the vertical displacement pattern 104b2 is the largest, the height of the vertical displacement pattern 104b3 is the smallest, and the height of the vertical displacement pattern 104b1 is intermediate between them. Therefore, by applying any one of the vertical displacement patterns 104b1, 104b2, 104b3 according to the position of the shoulder S of the subject M to be imaged, the vertical displacement of the X-ray detection unit 44 can be minimized within a range that can avoid the X-ray detection unit 44 from contacting the shoulder S, and the X-ray detection unit 44 can be brought closer to the head P to perform panoramic X-ray imaging. In the illustrated example, at the positions of the turning angles of ±90°, since the position of the shoulder S is higher than the vertical displacement pattern 104b3, the vertical displacement pattern 104b1 or 104b2 will be selected.

[0131] Let the height of the X-ray detection unit 44 with respect to the head P when the X-ray detection unit 44 is in front of the head P be the height FH, and let the height of the X-ray detection unit 44 with respect to the head P when the X-ray detection unit 44 is beside the head P be the height SH. Let the difference between the height FH and the height SH be the height difference FS. Therefore, the vertical displacement pattern 104b2 has a larger height difference FS than the vertical displacement pattern 104b3, and the vertical displacement pattern 104b3 has a smaller height difference FS than the vertical displacement pattern 104b2.

[0132] When a plurality of vertical displacement patterns 104b1, 104b2, 104b3 are included as the vertical displacement information 104b, in step S2, the user observes the physique or the like and makes a setting input as to which vertical displacement pattern 104b1, 104b2, 104b3 to apply, or inputs how much vertical displacement is to be made. In step S3, according to the selected pattern, the vertical displacement patterns 104b1, 104b2, 104b3 are read out and set as the vertical displacement pattern, or a vertical displacement pattern corresponding to the input vertical displacement amount is set. In this way, the setting of the height difference in the turning orbit R of the X-ray detection unit 44 can be changed.

[0133] The turning orbit R may be set so as to pass above the shoulder S or at least a part of the shoulder S at the timing when the X-ray detection unit 44 is located on the side of the head P. In this setting, the position on the XY coordinates of the X-ray detection unit 44 at the timing when the X-ray detection unit 44 is located on the side of the head P may be set with respect to the position of the shoulder S of a subject with a standard physique, or may be set according to an individual physique.

[0134] In the next step S4, it is determined whether or not acceptance of shooting start is received. The acceptance of shooting start may be made, for example, through a push button switch (referred to as a dead man switch) connected to the shooting control unit 100. When it is determined that there is no acceptance of shooting start, the process returns to step S2, and the processes of steps S2 and S3 are repeated. When it is determined that there is acceptance of shooting start, the process proceeds to step S5. When it is determined that there is no acceptance of shooting start, instead of returning to step S2, it may return to immediately after step S2 or immediately before step S4 itself.

[0135] It is possible to modify the initial setting in step S1 and the confirmation of whether or not to change the setting of the vertical displacement amount (height difference) in step S2 from the above. For example, as an initial setting in step S2, vertical displacement can be performed. In this case, whether or not to change the setting of the vertical displacement amount in step S2 is determined by whether or not there is a displacement amount change from the vertical displacement amount in step S1. For example, if the vertical displacement pattern 104b3 is set as the initial setting and the vertical displacement pattern 104b1 or 104b2 is required from the position of the shoulder S, it is determined that there is a setting change to increase the vertical displacement amount from small to large in step S2 by, for example, checking the input. The setting change of the vertical displacement amount may include a setting change to decrease the vertical displacement amount from large to small. For example, if the vertical displacement pattern 104b2 is set as the initial setting, but contact with the shoulder S can be sufficiently avoided, and rather a defect in the target area is likely to occur, it is to change to the vertical displacement pattern 104b3 or to change to no vertical displacement.

[0136] In step S5, the X-ray detection unit 44 is rotated to perform panoramic X-ray imaging. At this time, if vertical displacement is set, in synchronization with the rotation of the X-ray detection unit 44, the X-ray detection unit 44 is vertically displaced according to the set vertical displacement pattern. Thereby, vertical movement can be added to the X-ray detection unit 44 by the vertical drive unit 82 so that the lower end position of the X-ray detection unit 44 passing through the side of the head P is located higher than the lower end position of the X-ray detection unit 44 passing through the front of the head P with respect to the X-ray detection unit 44. If vertical displacement is not set, panoramic X-ray imaging without normal vertical displacement is performed.

[0137] During the rotation, the X-ray irradiated from the X-ray generation unit 42 passes through the head P and enters the X-ray detection unit 44. X-ray imaging data is generated based on the electrical signal corresponding to the X-ray detected by the X-ray detection unit 44, and the X-ray imaging data is provided to the image processing device 180. Thereby, the image processing device 180 generates a panoramic X-ray image based on the X-ray imaging data.

[0138] In performing panoramic X-ray imaging, the range of the panoramic imaging region and the like may be set through the operation display unit 110 or the like, and the X-ray beam shape adjustment unit 50 may be controlled according to the setting.

[0139] Also, in performing panoramic X-ray imaging, the elevation angle of the X-ray beam may be set through the operation display unit 110 or the like, and the X-ray beam shape adjustment unit 50 may be controlled according to the setting to adjust the irradiation direction of the X-ray beam. At the same time, the vertical position of the X-ray detector 44 may be adjusted by controlling the X-ray detector vertical movement drive unit 47 in accordance with the irradiation direction.

[0140] <Example of panoramic X-ray imaging> FIG. 11 is a diagram showing examples of the physiques of the imaging subjects M(1) and M(3). The imaging subjects M(1) and M(3) have different heights, and the height H(1) of the imaging subject M(1) is smaller than the height H(3) of the imaging subject M(3). The imaging subject M(1) has shoulders S(1) that slope downward in a standard manner with respect to the head P. The shoulders S(3) of the imaging subject M(3) are angry shoulders. The relative position of the shoulders S(3) with respect to the head P of the imaging subject M(3) is higher than the relative position of the shoulders S(1) with respect to the head P of the imaging subject M(1).

[0141] With reference to FIGS. 12 and 13, the case of performing panoramic X-ray imaging on the above-mentioned imaging subjects M(1) and M(3) will be described. In each of FIGS. 12 and 13, the positional relationship of the X-ray detector 44 with respect to the imaging subjects M(1) and M(3) viewed from the side is shown on the left side, and the positional relationship of the X-ray detector 44 with respect to the imaging subjects M(1) and M(3) viewed from the front is shown on the right side. In FIGS. 12 and 13, an example is shown in which the X-ray beam is irradiated upward, and the lower ends of the housing 41 that houses the X-ray generator 43 and the lower end of the housing 46 that houses the X-ray detector 45 are aligned at the same height position. It is not essential that the X-ray beam be irradiated upward. Therefore, the lower end of the housing 41 that houses the X-ray generator 43 may be located below the lower end of the housing 46 that houses the X-ray detector 45.

[0142] When the subject is the person being photographed M(1), as shown in Fig. 12, the X-ray detection unit 44 can rotate in front of the head P without contacting the person being photographed M(1). Also, the shoulder S(1) slopes downward in a standard manner with respect to the head P. For this reason, on the side of the head P, the shoulder S(1) is positioned below the chin tip of the head P or the like. For this reason, it is difficult for the X-ray detection unit 44 to contact the shoulder S(1) even on the side of the head P. Therefore, even without vertically displacing the X-ray detection unit 44, panoramic X-ray imaging can be performed by rotating the X-ray detection unit 44 around the head P.

[0143] When the subject is the person being photographed M(3), as shown in Fig. 13, the X-ray detection unit 44 can rotate in front of the head P without contacting the person being photographed M(3). However, the shoulder S(3) is a hunched shoulder. For this reason, on the side of the head P, the shoulder S(3) may be positioned near the height of the chin tip of the head P or the like.

[0144] In this case, the X-ray detection unit 44 may contact the shoulder S(3) on the side of the head P (see the position of the X-ray detection unit 44(L) in Fig. 13). In such a case, with the X-ray detection unit 44 positioned on the side of the head P, it is also conceivable to perform panoramic X-ray imaging without vertically displacing the X-ray detection unit 44 while it is arranged at a height position where it does not contact the shoulder S(3) (see the lowermost end position of the X-ray detection unit 44(H)). However, in this case, the lowermost end of the X-ray detection unit 44 may be positioned above the chin tip, and in the panoramic X-ray image, the front lower end of the dental arch Arc may not be captured. Therefore, a vertical displacement pattern is set as described in steps S2 and S3 above, and as described in step S5, an X-ray detection orbit is set to vertically displace the X-ray detection unit 44 such that the X-ray detection unit 44 is low in front of the head P and high on the side of the head P (see the X-ray detection unit 44(H) in Fig. 13). Thereby, while avoiding the X-ray detection unit 44 from contacting the shoulder S, the X-ray detection unit 44 can be rotated along the rotation orbit R. Thereby, a panoramic X-ray image in which the front lower end of the dental arch Arc is captured can be generated while avoiding the X-ray detection unit 44 from contacting the shoulder S(3).

[0145] According to the X-ray imaging apparatus 20 configured as described above, when the X-ray generating unit 42 and the X-ray detecting unit 44 rotate around the head P located therebetween, a movement that avoids contact with the subject M is added to the X-ray detecting unit 44. For this reason, while suppressing the X-ray detecting unit 44 from hitting the shoulder, the X-ray detecting unit 44 can be brought closer to the head P as much as possible. In other words, even if the rotation orbit of the X-ray detecting unit 44 is an orbit close to the head P, it is possible to suppress the X-ray detecting unit 44 from hitting the shoulder. And if the X-ray detecting unit 44 can be brought closer to the head, the X-rays transmitted through the head P are clearly projected onto the X-ray detecting unit 44, and thereby, the resolution of the panoramic X-ray image can be improved.

[0146] When the X-ray detecting unit 44 is vertically displaced according to the above vertical displacement patterns 104b1, 104b2, 104b3, an oblique panoramic X-ray image in which a region gradually rising upward from the front to the rear is reflected is generated in a side view. Since the dental arch Arc extends so as to gradually rise upward from the front to the rear in a side view, the dental arch Arc can also be sufficiently reflected in the oblique panoramic X-ray image.

[0147] In addition, it is unlikely that there is a human body part that is likely to come into contact with the rotating X-ray detecting unit 44 below the front of the head P. Below the side of the head P, a shoulder S may exist as a human body part that is likely to come into contact with the rotating X-ray detecting unit 44. Therefore, if the displacement mechanism is the vertical drive unit 82 which is an example of the position of the vertical displacement mechanism that vertically displaces the X-ray detecting unit 44 with respect to the head P, when the X-ray detecting unit 44 passes in front of the head P, the X-ray detecting unit 44 can be positioned lower, and when the X-ray detecting unit 44 passes beside the head P, the X-ray detecting unit 44 can be positioned higher. Thereby, while suppressing the X-ray detecting unit 44 from contacting the shoulder S, an effective movement for bringing the X-ray detecting unit 44 closer to the head P can be added.

[0148] For example, at a front position of the head P, the X-ray detecting unit 44 may be at a height located around the center of the dental arch and the outer periphery of the jaw tip. Also, at a side position of the head P, it may be at a height located around the outer periphery from the temporomandibular joint to the mandibular angle at both ends of the dental arch Arc.

[0149] Further, if the vertical drive unit 82 is a mechanism that moves the swing arm 40 up and down with respect to the head P, by moving the swing arm 40 up and down, the X-ray generation unit 42 and the X-ray detection unit 44 can be moved up and down together. Therefore, during the swing of the X-ray detection unit 44, it is possible to keep the relative positional relationship between the X-ray generation unit 42 and the X-ray detection unit 44 constant, and separate height control, launch angle control, etc. become unnecessary.

[0150] Also, if the drive mechanism 60 includes a swing mechanism 62 and a two-dimensional movement mechanism (axial movement mechanism 70), when swinging the X-ray generation unit 42 and the X-ray detection unit 44, the two-dimensional movement mechanism (axial movement mechanism 70) can move the X-ray generation unit 42 and the X-ray detection unit 44 in a two-dimensional direction along their swing planes. Thereby, the swing orbit of the X-ray generation unit 42 and the X-ray detection unit 44 can be changed to another orbit that is not a circular orbit. For example, it can be set to a swing orbit in which the X-ray detection unit 44 approaches the surface of the head P in front of the head P and moves away from the surface of the head P on the side of the head P. Thereby, it is easy to set an orbit that approaches the X-ray detection unit 44 to the head P as much as possible while avoiding contact with the shoulder S.

[0151] In particular, if the two-dimensional movement mechanism is an axial movement mechanism 70 that moves the swing axis portion 96 in a direction intersecting the axial direction of the swing axis X1, in synchronization with the swing mechanism 62 swinging the swing arm 40, the axial movement mechanism 70 moves the swing axis portion 96, and by causing the swing arm 40 to perform a combined movement, the swing orbit of the X-ray detection unit 44 can be changed.

[0152] <Modification Example> A modification example of the first embodiment will be described. In the first embodiment, the vertical displacement amount may be set based on the detection result from the detection unit that detects the position of the shoulder S. For example, as shown in FIG. 14, the imaging device 22 captures the front and side views of the subject M. In the captured image 220, a front image 221 including the head P and the shoulder S is captured. The captured image 220 may include a side image 222 including the head P and the shoulder S. Based on the captured image 220, the imaging control unit 100 executes image recognition processing such as edge extraction processing to extract the upper boundary of the shoulder S and the like. Then, the height position of the shoulder S in the passing area of the set turning orbit R is recognized. Since the front image 221 and the side image 222 represent the physique of the subject M, the imaging device 22 is an example of a physique detection unit that detects the physique of the subject M. The imaging control unit 100 may set the movement orbit of the X-ray detection unit 44 according to the detected physique. The imaging control unit 100 controls the driving of the vertical driving unit 82 according to the detection result by the imaging device 22. The imaging control unit 100 determines whether it is necessary to perform vertical movement to avoid contact with the shoulder S according to the detection result by the imaging device 22. When it is determined that it is necessary, the imaging control unit 100 controls the vertical driving unit 82 to add vertical movement to the X-ray detection unit 44. Further, for example, the imaging control unit 100 calculates how much the X-ray detection unit 44 needs to be raised to avoid contact with the shoulder S with respect to the height position of the lower end of the X-ray detection unit 44 initially set for the subject M. Based on this calculation result, the vertical displacement amount of the X-ray detection unit 44 is determined, and based on the vertical displacement amount, a vertical displacement pattern can be set to set a safe X-ray detection orbit. In this way, the setting of the height difference in the turning up-and-down orbit REL of the X-ray detection unit 44 can be changed.

[0153] FIG. 15 is a flowchart showing a processing example of the imaging control unit 100 according to this modification example.

[0154] Step S11 is the same as step S1 above. In step S12 after step S11, it is determined whether there is a setting change in the vertical displacement amount. When a setting change instruction for the vertical displacement amount is input according to a touch operation or the like on the operation display unit 110 or the like, it is determined that there is a vertical displacement amount setting change, and the process proceeds to step S13. If no setting change instruction is input, the process proceeds to step S15.

[0155] In steps S13 and S14, the imaging device 22 as the physique detection unit photographs the head P and the shoulders S, thereby detecting the physique of the photographed person M, and determining at least one of the presence or absence of vertical movement and the amount of vertical movement according to the detected physique of the photographed person M.

[0156] That is, in step S13, the imaging device 22 images the head P and the shoulders S held by the subject holding unit 32. For example, the X-ray detection unit 44 may be rotated along a turning orbit that is difficult to contact the photographed person M (an orbit sufficiently far from the head P), and the image data obtained by imaging the head P from a plurality of directions may be used as the detection result. Since this image data includes the surface shapes of the head P and the shoulders S, the image data is an example of physique data including the physique related to the head P and the shoulders S of the photographed person M. The imaging control unit 100 executes image recognition processing such as edge extraction processing on the captured image 120, for example, to extract the upper boundary of the shoulder S or the like. Thereby, the physique of the photographed person M can be grasped as data. Note that the positional relationship between the imaging device 22 and the turning arm 40 and the X-ray detection unit 44 can be regarded as known information. Therefore, the imaging range by the imaging device 22 with respect to the turning arm 40 and the X-ray detection unit 44 can also be regarded as known information. Thus, the boundary position of the shoulder S in the captured image 120 can be obtained as the relative position with respect to the turning arm 40 and the X-ray detection unit 44.

[0157] In step S14, a vertical displacement pattern is set based on the detected physique. The setting of the vertical displacement pattern here includes whether to set a vertical displacement pattern for vertically displacing the X-ray detection unit 44. The setting of the vertical displacement pattern also includes settings such as how much the X-ray detection unit 44 is vertically displaced.

[0158] For example, based on the captured image 120 (particularly the front image 221), the upper boundary position of the shoulder S at the position corresponding to the turning orbit R is specified. This boundary position is set as the lower limit position below the lower end of the X-ray detector 44 on the side of the head P. Based on the initial height position of the X-ray detector 44 set at the initial stage of imaging (for example, set as a position suitable for imaging the front of the dental arch Arc), it is calculated how much the X-ray detector 44 needs to be moved upward from the initial position in front of the head P so that the lower end of the X-ray detector 44 is arranged at the same or above the lower limit position. If the required upward movement amount is "0", there is no need to set the vertical displacement pattern. When the required upward movement amount exceeds "0", the vertical displacement pattern is set. The vertical displacement pattern may be set according to the magnitude of the required movement amount. For example, when the vertical displacement information 104b includes a plurality of vertical displacement patterns 104b1, 104b2, 104b3, the one with the smallest vertical movement amount among the vertical displacement patterns 104b1, 104b2, 104b3 that is equal to or greater than the required movement amount may be set as the vertical displacement pattern corresponding to the detected body build. When the vertical displacement pattern is expressed by a relational expression or the like with the vertical movement amount as a variable, the vertical displacement pattern corresponding to the detected body build may be set by substituting the required movement amount as the vertical displacement amount into the relational expression.

[0159] The imaging device 22 may image the head P and the shoulder S from a plurality of directions, and the imaging control unit 100 may generate three-dimensional surface shape data representing the surface shapes of the head P and the shoulder S based on the captured images from the plurality of directions. The imaging control unit 100 can also specify the vertical position of the shoulder S in the turning orbit R based on such three-dimensional surface shape data.

[0160] The body detection unit may be a mobile terminal device 300 having an imaging device such as a smartphone or a tablet terminal device (see FIG. 2). The mobile terminal device 300 captures an image in which the head P and the shoulder S and the reference part in the X-ray imaging device 20 are captured, and performs image processing and the like based on the captured image, thereby recognizing the surface position of the shoulder S in the X-ray imaging device 20. Thereby, similarly to the above, an up-and-down displacement pattern corresponding to the physique can be set.

[0161] Also, for example, a visible light sensor or a laser sensor for detecting the position of the shoulder S may be incorporated in the swivel arm 40, and the physique, particularly the position of the shoulder S, may be detected based on the output of the sensor. Data including those detection results is an example of physique data. Based on those detection results, since the position of the shoulder S is specified, similarly to the above, an up-and-down displacement pattern can be set.

[0162] If it is determined in step S12 that there is no change in the up-and-down displacement amount setting, and after the up-and-down displacement pattern is set in step S14, the process proceeds to step S15. In step S15, similarly to step S4, it is determined whether or not an acceptance of the start of imaging is received. If it is determined that the acceptance of the start of imaging is not received, the process returns to step S12, and if it is determined that the acceptance of the start of imaging is received, the process proceeds to step S16. If it is determined that the acceptance of the start of imaging is not received, instead of returning to step S12, the process may return to an appropriate process between immediately after step S12 and immediately before step S15 itself.

[0163] In step S16, similarly to step S5, panoramic X-ray imaging is performed while rotating the X-ray detection unit 44. At this time, if the up-and-down displacement pattern is set, the X-ray detection unit 44 is displaced up and down in synchronization with the rotation of the X-ray detection unit 44. Thereby, it is possible to perform panoramic X-ray imaging by rotating the X-ray detection unit 44 while avoiding contact of the X-ray detection unit 44 with the shoulder S according to the individual physique of the imaging subject M.

[0164] According to this modification example, the imaging control unit 100 controls the driving of the vertical driving unit 82 according to the detection result by the imaging device 22 which is an example of the physique detection unit. Therefore, according to the physique of the imaging subject M, the operation of the vertical driving unit 82 can be controlled to suppress the shoulder contact of the X-ray detection unit 44.

[0165] In the above example, the explanation was made on the premise that the vertical position when the X-ray detection unit 44 passes through the front part of the head P is initially set by the user or the like. Based on the above side view or the like, the position of the chin tip can be specified, and the vertical position when the X-ray detection unit 44 passes through the front part of the head P may be set based on the position of the chin tip. For example, the vertical position when the X-ray detection unit 44 passes through the front part of the head P may be set so that the lower end of the X-ray detection unit 44 or the lower edge of the detection surface of the X-ray detector 45 coincides with the position of the chin tip.

[0166] According to this modification example, according to the physique of the imaging subject M, the operation of the vertical driving unit 82 can be controlled to suppress the shoulder contact of the X-ray detection unit 44. In particular, by controlling the operation of the vertical driving unit 82 according to the detection result by the imaging device 22 which is an example of the physique detection unit, while minimizing the vertical displacement amount of the X-ray detection unit 44, it can contribute to suppressing the shoulder contact of the X-ray detection unit 44 and performing panoramic X-ray imaging.

[0167] For example, the imaging control unit 100 determines whether vertical movement to avoid contact with the shoulder S is necessary according to the detection result by the imaging device 22 which is an example of the physique detection unit, and when it is determined to be necessary, it is conceivable to add vertical movement to the X-ray detection unit 44 by the vertical driving unit 82. Thereby, depending on the physique (for example, refer to the imaging subject M(1)), a panoramic X-ray image taken without vertically displacing the X-ray detection unit 44 can be obtained. Thereby, a situation where the lower part of the imaging target area including the dental arch Arc or the like is not reflected in the panoramic X-ray image is avoided.

[0168] In addition, the imaging control unit 100 determines the vertical displacement amount for avoiding contact with the shoulder S according to the detection result by the imaging device 22 which is an example of the physique detection unit, and according to the determined vertical displacement amount, it is conceivable to add vertical movement to the X-ray detection unit 44 by the vertical drive unit 82, such as the vertical displacement patterns 104b1, 104b2, and 104b3. Thereby, panoramic X-ray imaging can be performed with an appropriate amount according to the physique, for example, with a vertical displacement amount that is as small as possible within the range of avoiding contact with the shoulder S according to the physique. In particular, when performing panoramic X-ray imaging with the X-ray detection unit 44 extremely close, such as within 10 cm from the head P, the X-ray detection unit 44 is likely to contact the shoulder S. In such a case, it is effective that the vertical displacement amount can be set to be as small as possible within the range where contact with the shoulder S can be avoided.

[0169] In this modification example, an example of setting the presence or absence of the vertical displacement pattern and the vertical displacement amount when setting the vertical displacement pattern according to the detection result of the physique has been described. However, according to the detection result of the physique, only the presence or absence of the setting of the vertical displacement pattern may be performed, or only the vertical displacement amount may be set on the premise of performing vertical displacement.

[0170] In the flowchart of FIG. 15, an instruction for changing the vertical displacement amount setting is received at step S12. If there is an instruction for changing the vertical displacement amount setting, the physique is detected at step S13 and the vertical displacement pattern based on the physique is set at step S14, but the progress may be fully automatic. That is, step S12 may be omitted. First, the physique is detected at step S13, and the imaging control unit 100 automatically determines whether or not it is necessary to change the vertical displacement amount setting. If necessary, the vertical displacement amount setting is changed, and if not, the current vertical displacement pattern setting is maintained. In this case, when the answer at step S15 is NO, it may be a loop that returns to just before step S15. Furthermore, the initial setting without vertical displacement may be omitted. In this case, step S11 is omitted. For example, such progress can be used when the specification is such that the settings of the previous imaging are left.

[0171] {Second Embodiment} The X-ray imaging apparatus 200 according to the second embodiment will be described. In the description of the present embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. FIG. 16 is a block diagram showing an example of the electrical configuration of the X-ray imaging apparatus 200.

[0172] In the second embodiment, an example in which a first turning orbit R1 and a second turning orbit R2 can be set as the turning orbit R of the X-ray detection unit 44 in panoramic X-ray imaging for the same imaging subject M will be described. That is, depending on the case of the imaging subject M, there may be a case where panoramic X-ray imaging is performed with the X-ray detection unit 44 brought closer to the head P, and thereby a clearer panoramic X-ray image is desired. In such a case, if a turning orbit in which the X-ray detection unit 44 is brought closer to the head P can be set within a range where contact between the X-ray detection unit 44 and the shoulder S can be avoided according to the physique of the imaging subject M, the panoramic X-ray image can be made clearer.

[0173] In the present embodiment, an example is shown in which when a turning orbit in which the X-ray detection unit 44 is brought closer to the head P is set, the X-ray detection unit 44 is vertically displaced to avoid hitting the shoulder S.

[0174] In this X-ray imaging apparatus 200, in addition to the processing functions of the imaging program 104a, the imaging program 204a stored in the storage unit 104 can set a first turning orbit R1 and a second turning orbit R2 as the panoramic turning orbits of the X-ray detection unit 44 for the same imaging subject, and has a function of selectively setting any one of them as the actual turning orbit during panoramic X-ray imaging. Further, the storage unit 104 stores a first turning orbit information 204b and a second turning orbit information 204c as turning orbit information 204. The first turning orbit information 204b and the second turning orbit information 204c are information for determining the orbit of the X-ray detection unit 44 when performing panoramic X-ray imaging. The first turning orbit information 204b and the second turning orbit information 204c define different orbits from each other. The processor 102 includes an orbit setting unit 102g that sets the turning orbit based on the first turning orbit information 204b and the second turning orbit information 204c in addition to the functions in the first embodiment by executing processing according to the imaging program 204a. The second turning orbit R2 may be set so that it is closer at least in part than the first turning orbit R1 when compared with the first turning orbit R1.

[0175] The second turning orbit R2 may be set so that it passes above the shoulder S or at least a part of the shoulder S at the timing when the X-ray detection unit 44 is located on the side of the head P. In this setting, the position on the XY coordinates of the X-ray detection unit 44 at the timing when the X-ray detection unit 44 is located on the side of the head P may be set with respect to the position of the shoulder S of a subject with a standard physique, or may be set according to an individual physique.

[0176] Furthermore, the first turning orbit R1 may be set so that it does not pass above the shoulder S at the timing when the X-ray detection unit 44 is located on the side of the head P.

[0177] The first turning orbit information 204b and the second turning orbit information 204c are information that defines the turning orbit of the X-ray detection unit 44. As described above, the movement of the X-ray detection unit 44 is a combined movement of the turning operation of the X-ray detection unit 44 by the turning mechanism 62 and the movement operation of the turning shaft portion 96 by the axial movement mechanism 70 during turning by the turning mechanism 62. For this reason, the first turning orbit information 204b and the second turning orbit information 204c may be, for example, information associating the turning operation of the X-ray detection unit 44 by the turning mechanism 62 with the movement path of the turning shaft portion 96 by the axial movement mechanism 70 with respect to the turning operation. The turning operation of the X-ray detection unit 44 by the turning mechanism 62 may be expressed, for example, as the rotation angle of the X-ray detection unit 44 with respect to any initial angle. The movement path of the turning shaft portion 96 may be expressed, for example, by data defining changes in the rotation direction and rotation speed of the X-axis drive motor 76a and the Y-axis drive motor 76b that move the turning shaft portion 96, a data series of XY coordinates defining the position of the turning shaft portion 96, or a relational expression using the x coordinate and the y coordinate as variables. The support control unit 102a can control the turning mechanism 62 and the axial movement mechanism 70 based on the first turning orbit information 204b or the second turning orbit information 204c, so that the X-ray detection unit 44 can be turned along the first turning orbit R1 defined by the first turning orbit information 204b or the second turning orbit R2 defined by the second turning orbit information 204c.

[0178] Examples of the first turning orbit R1 and the second turning orbit R2 will be described. FIG. 17 shows an example in which the first turning orbit R1 and the second turning orbit R2 are set as the turning orbit R. The turning orbit R1 shown in FIG. 17(a) is an example of the first turning orbit R1. An example of the second turning orbit R2 is shown in FIG. 17(b). In FIGS. 17(a) and 17(b), the shape of the head P and the shape of the shoulder S are shown. The shapes of the head P and the shoulder S are assumed to be standard.

[0179] The first turning orbit R1 and the second turning orbit R2 are arc-shaped lines along the outer peripheral side of the dental arch Arc. The first turning orbit R1 and the second turning orbit R2 may be set within a range capable of detecting X-rays that penetrate the anterior teeth and molars in the dental arch, and further, a region including the vicinity of the mandibular angle from the temporomandibular joint. From this perspective, the first turning orbit R1 and the second turning orbit R2 may be arc-shaped orbits within a range exceeding 90° to the left and right (for example, a range of ±115°) centered on the front part at the center in the left-right direction of the head P.

[0180] The second turning orbit R2 is set to an orbit closer to the head surface than the first turning orbit R1 at least in either the front (at least in the front at the center in the left-right direction of the head P) or the side (at least in the left-right direction at the center in the front-back direction of the head P) of the head P. For this reason, the X-ray detection unit 44 that turns along the second turning orbit R2 can approach the dental arch Arc, which is the region of interest, to detect X-rays. In the illustrated example, the second turning orbit R2 is set to an orbit closer to the head surface than the first turning orbit R1 in both the front and the side of the head P.

[0181] As shown in FIGS. 17(a) and 17(b), in order to move the X-ray detection unit 44 along the first turning orbit R1 or the second turning orbit R2, for example, when the X-ray detection unit 44 turns around the turning shaft portion 96, the turning shaft portion 96 may be moved by the axial movement mechanism 70. For example, the position of the turning shaft portion 96 may be adjusted according to the distance between the first turning orbit R1 or the second turning orbit R2 and the surface of the head P. For example, in the portion of the turning orbits R1, R2 that approaches the surface of the head P, the movement approaching the surface is realized by moving the turning shaft portion 96 in the reverse irradiation direction, and in the portion of the turning orbits R1, R2 that moves away from the surface of the head P, the movement away from the surface is realized by moving the turning shaft portion 96 in the forward irradiation direction.

[0182] The movement trajectory Q2 of the swivel shaft portion 96 corresponding to the second swivel trajectory R2 is set to a position that advances in the reverse irradiation direction behind and laterally of the head P, compared to the movement trajectory Q1 of the swivel shaft portion 96 corresponding to the first swivel trajectory R1. As a result, the X-ray detector 44 moving along the second swivel trajectory R2 approaches the surface of the head P closer than the X-ray detector 44 moving along the first swivel trajectory R1, in front of and laterally of the head P.

[0183] The first swivel trajectory R1 may be a trajectory adapted to the standard shape of the head P. That is, the first swivel trajectory R1 may be set to a path that allows the X-ray detector 44 to swivel around the head P without contacting the standard head P, taking into account the shape and size of the X-ray detector 44 with respect to the standard shape of the head P.

[0184] Here, the standard shape of the head P may mean the average head shape in the country or region where the present X-ray imaging apparatus 20 is used, regardless of age, gender, etc. of adults or children. The standard shape of the head P may mean the average head in the country or region where the present X-ray imaging apparatus 20 is used, targeting adults in that country or region. The standard head P also has a standard shape and size of the dental arch Arc within the head P. Therefore, the first swivel trajectory R1 may be set to swivel within a range where such a dental arch Arc can exist. Of course, a plurality of groups may be distinguished, for example, adults and children may be distinguished, and each group may be adapted to the average head shape of each group.

[0185] The second swivel trajectory R2 may be similar in shape and smaller than the first swivel trajectory R1. Also, the degree of contraction of the left-right width (X-direction width) of the second swivel trajectory R2 with respect to the left-right width (X-direction width) of the first swivel trajectory R1 is greater than the degree of contraction of the front-rear length (Y-direction length) of the second swivel trajectory R2 with respect to the front-rear length (Y-direction length) of the first swivel trajectory R1. Therefore, the second swivel trajectory R2 may be a shape that is more contracted in the left-right (X-direction) than in the front-rear (Y-direction) with respect to the first swivel trajectory R1.

[0186] The second turning orbit R2 is also an orbit that is closer to the chin rest 33 than the first turning orbit R1 in front of the chin rest 33 which is an example of the anterior tooth region fixing part. The second turning orbit R2 is also an orbit that is closer to the surface of the head P than the first turning orbit R1 in front of the head P. Further, the second turning orbit R2 is also an orbit that is closer to the chin rest 33 than the first turning orbit R1 in the left - right direction of the imaging subject M held by the subject holding part 32, that is, in the X direction.

[0187] In relation to the shape of the head P, the second turning orbit R2 may be an orbit that passes through a position within 10 cm from the surface of the head P in front of the head P (at least in front of the center in the left - right direction (X direction) of the head P).

[0188] The second turning orbit R2 may be an orbit in which the partial orbit in the front range of the anterior tooth region Pa approaches the surface of the head P more than the partial orbits in other ranges. In other words, the second turning orbit R2 may be an orbit in which the region part at the center in the left - right direction (X direction) of the head P is closest to the surface of the head P with respect to other region parts.

[0189] In these cases, in front of the head P, since there is no shoulder S where the X - ray detection part 44 is likely to come into contact, the X - ray detection part 44 can easily approach the head P without contacting the imaging subject M.

[0190] Furthermore, the second turning orbit R2 may be an orbit that passes through a position within 10 cm from the surface of the head P over the whole around the head P. In this case, it is advisable to check whether the X - ray detection part 44 contacts the shoulder S according to the shape of the shoulder S of the imaging subject M. When there is a possibility that the X - ray detection part 44 contacts the shoulder S, it is conceivable to stop setting the second turning orbit R2 itself or adjust the vertical position of the X - ray detection part 44 during turning along the second turning orbit R2. A modification example in this case will be described later.

[0191] At least one of the first turning orbit R1 and the second turning orbit R2 may be an orbit in which the distance from the surface of the head P on the side of the head P is greater than the distance from the surface of the head P in front of the head P. In other words, at least one of the first turning orbit R1 and the second turning orbit R2 may be a forward approaching orbit. That is, it may be an orbit in which the distance from the surface of the head P at the center in the front-rear direction (Y direction) of the head P is farther than the distance from the surface of the head P at the center in the left-right direction (X direction) of the head P. More specifically, the distance from the surface of the side part of the head P at the center in the front-rear direction (Y direction) of the side part of the head P where the X-ray detection unit 44 faces the side part of the head P during the turning orbit is the left-right direction (X direction) of the front part of the head P where the X-ray detection unit 44 faces the front part of the head P during the turning orbit. It may be an orbit that is farther than the distance from the surface of the front part of the head P at the center.

[0192] The first turning orbit R1 may be set as shown in Fig. 17(a), and the second turning orbit R2 may be set as shown in Fig. 9. The approach degree of the second turning orbit R2 on the side of the head may be set higher than the approach degree of the first turning orbit R1. In this case, the height difference FS2 of the second turning orbit R2 may be made larger than the height difference FS1 of the first turning orbit R1. Further, depending on the physique, the difference between the height difference FS2 of the second turning orbit R2 and the height difference FS1 of the first turning orbit R1 may be made larger or smaller. For example, for the subject M(3) with angry shoulders, the difference between the height difference FS2 of the second turning orbit R2 and the height difference FS1 of the first turning orbit R1 may be made larger than that of the subject M(1) with standard sloping shoulders.

[0193] Here, a part that protrudes from the roundness of the head in the -Z direction view, such as the nose or the ear, or both, will be referred to as the head protrusion. When considering the distance between the head and the X-ray detection unit 44, it may be considered as the distance from the surface including the head protrusion, or it may be considered as the distance from the roundness of the head assuming that there is no head protrusion. It is also possible to assume that only some of the multiple head protrusions, such as only the nose, do not exist.

[0194] While a protrusion of the body is difficult to observe below the front of the head P, the shoulder S can be observed below the side of the head P. Therefore, when the X-ray detection unit 44 passes through the side of the head P, there is a risk that the X-ray detection unit 44 contacts the shoulder S. Generally, the upper surface of the shoulder S has a shape that faces downward as it moves away from the surface of the head P. Therefore, on the side of the head P, by passing the X-ray detection unit 44 at a position away from the surface of the head P, it becomes difficult for the X-ray detection unit 44 to contact the shoulder S.

[0195] FIG. 18 is a flowchart showing an example of the processing of the imaging control unit 202 of the X-ray imaging apparatus 200.

[0196] When the panoramic imaging mode process is started, in step S21, the first turning orbit R1 is set as the initial orbit or the default orbit based on the first turning orbit information 204b. The first turning orbit R1 may be a general-purpose turning orbit that has been conventionally adopted in panoramic X-ray imaging apparatuses. Therefore, when there is no special instruction regarding the turning orbit, panoramic X-ray imaging is performed by turning the X-ray detection unit 44 along the first turning orbit. Also, no vertical displacement is set as the initial operation. Therefore, when there is no special instruction to change the vertical displacement amount, the X-ray detection unit 44 performs panoramic X-ray imaging without vertical displacement.

[0197] In the next step S22, it is confirmed whether there is a setting change to the second turning orbit R2. The setting change to the second turning orbit R2 is made, for example, through the operation display unit 110. For example, an icon for setting change to the second turning orbit R2 is displayed on the operation display unit 110, and by touching the icon, the setting change to the second turning orbit is accepted. When it is determined that there is a setting change to the second turning orbit R2, the process proceeds to step S23, and when it is determined that there is no setting change, step S23 is skipped and the process proceeds to step S24.

[0198] In step S23, based on the second turning orbit information 204c, the second turning orbit R2 is set as the turning orbit. After that, the process proceeds to step S24.

[0199] In step S24, similar to step S2, it is determined whether there is a setting for the vertical displacement amount. If it is determined that there is a setting change for the vertical displacement amount, the process proceeds to step S25. If it is determined that there is no setting change, step S25 is skipped and the process proceeds to step S26.

[0200] In step S25, based on the set vertical displacement amount, a vertical displacement pattern is set. When the approach degree of the second turning orbit R2 on the head side is set higher than the approach degree of the first turning orbit R1, the second turning orbit R2 with a height difference FS2 larger than the height difference FS1 of the first turning orbit R1 is configured to be set or selectable so that the height difference FS2 of the second turning orbit R2 can be made larger than the height difference FS1 of the first turning orbit R1. Based on the detection result by the imaging device 22 serving as the physical condition detection unit, the height difference FS2 of the second turning orbit R2 may be configured to be larger than the height difference FS1 of the first turning orbit R1. The vertical displacement pattern in the second turning orbit R2 may be selected from a plurality. Further, the vertical displacement pattern in the first turning orbit R1 may also be selected from a plurality. [[ID=,6]]

[0201] In the next step S26, similar to step S4, it is determined whether reception of the start of shooting is accepted. If it is determined that the start of shooting is not accepted, the process returns to step S22 and the processes after step S22 are repeated. If it is determined that the start of shooting is accepted, the process proceeds to step S27. When it is determined that the start of shooting is not accepted, instead of returning to step S22, the process may return to an appropriate process between immediately after step S22 and immediately before step S26 itself.

[0202] In step S27, panoramic X-ray imaging is performed while rotating the X-ray detector unit 44 according to the set turning trajectory. That is, according to the set first turning trajectory information 204b or second turning trajectory information 204c, the turning mechanism 62 and the axis moving mechanism 70 are controlled to rotate the X-ray detector unit 44 along the first turning trajectory R1 or the second turning trajectory R2. In panoramic X-ray imaging, since the entire turning arm 40 rotates and moves, the X-ray generating unit 42 also rotates. At this time, when a vertical displacement pattern is set, in synchronization with the rotation of the X-ray detector unit 44, the vertical drive unit 82 is controlled to move the turning arm 40 in the vertical direction, thereby vertically displacing the X-ray detector unit 44 according to the vertical displacement pattern. At this time, by controlling the holding unit drive unit 36, the subject holding unit 32 may be displaced in the direction opposite to the vertical direction of the movement of the turning arm 40 to keep the height position of the subject holding unit 32 constant. Thereby, X-ray imaging data is obtained. The image processing apparatus 180 generates a panoramic X-ray image based on the X-ray imaging data.

[0203] <Example of panoramic X-ray imaging> As shown in FIG. 19, taking imaging subjects M(1), M(2), and M(3) having different physiques as examples, an example of panoramic X-ray imaging will be described. The imaging subjects M(1) and M(2) have different heights, and the height H(1) of the imaging subject M(1) is greater than the height H(2) of the imaging subject M(2). The imaging subjects M(1) and (2) have shoulders S(1) and S(2) with a standard downward slope with respect to the head P. The height H(3) of the imaging subject M(3) is greater than the heights H(1) and H(2) of the imaging subjects M(1) and M(2). The shoulder S(3) of the imaging subject M(3) is an angry shoulder. The relative position of the shoulder S(3) with respect to the head P of the imaging subject M(3) is higher than the relative positions of the shoulders S(1) and S(2) with respect to the head P of the imaging subjects M(1) and M(2).

[0204] Consider the case where panoramic X-ray imaging is performed by rotating the X-ray detector unit 44 along the first turning trajectory R1.

[0205] When the subject to be photographed is M(1), as shown in FIG. 20, the X-ray detection unit 44 passes through a position away from the head P even on the side of the head P. At a position away from the side of the head P according to the first turning orbit R1, the shoulder S(1) is located below the chin tip of the head P or the like. For this reason, it is difficult for the X-ray detection unit 44 to come into contact with the shoulder S(1) even on the side of the head P. Therefore, panoramic X-ray photography can be performed by turning the X-ray detection unit 44 around the head P without vertically displacing the X-ray detection unit 44.

[0206] When the subject to be photographed is M(2), as shown in FIG. 21, according to the height H(2) of the subject M(2), the turning arm 40 that holds the X-ray generation unit 42 and the X-ray detection unit 44 and the subject holding unit 32 are positioned lower than in the case shown in FIG. 20. In this state, panoramic X-ray photography can be performed in the same manner as in the case shown in FIG. 19.

[0207] When the subject to be photographed is M(3), as shown in FIG. 22, the X-ray detection unit 44 passes through a position away from the head P even on the side of the head P. When the subject M(3) has a physique such as angry shoulders, the shoulder S(3) may be located near the height position of the chin tip of the head P even at a position away from the side of the head P(1) according to the first turning orbit R1. <s

[0208] In this case, the X-ray detection unit 44 may come into contact with the shoulder S(3) on the side of the head P (see the position of the X-ray detection unit 44(L) in FIG. 22). In such a case, it is also conceivable to perform panoramic X-ray photography without vertically displacing the X-ray detection unit 44 in a state where the X-ray detection unit 44 is arranged at a height position (see the lowermost end position of the X-ray detection unit 44(H)) that does not come into contact with the shoulder S(3) while the X-ray detection unit 44 is located on the side of the head P. However, in this case, the lowermost end of the X-ray detection unit 44 may be located above the chin tip, and the front lower end portion of the dental arch Arc may not be captured in the panoramic X-ray image.

[0209] Therefore, as described in the above steps S24 and S25, a vertical displacement pattern is set, and as described in step S27, the X-ray detection unit 44 is vertically displaced so that it is low in front of the head P and high on the side of the head P. Thereby, while avoiding the X-ray detection unit 44 from contacting the shoulder S, the X-ray detection unit 44 can be rotated along the first rotation orbit R1. Thereby, while avoiding the X-ray detection unit 44 from contacting the shoulder S(3), a panoramic X-ray image in which the front lower end of the dental arch Arc is captured can be generated.

[0210] Therefore, when the X-ray detection unit 44 rotates along the first rotation orbit R1, according to the physique, for example, the X-ray detection unit 44 may not be vertically displaced (in the case of the imaging subjects M(1) and M(2)), or may be vertically displaced (in the case of the imaging subject M(3)), and panoramic X-ray imaging can be performed. By performing panoramic X-ray imaging without vertically displacing the X-ray detection unit 44, the mechanical movement during panoramic X-ray imaging can be simplified. By performing panoramic X-ray imaging with the X-ray detection unit 44 vertically displaced, contact between the X-ray detection unit 44 and the shoulder S is suppressed.

[0211] Note that even in the case of the imaging subject M(3), panoramic X-ray imaging may be performed by rotating the X-ray detection unit 44 at a certain height position where the X-ray detection unit 44 does not contact the shoulder S on the side of the head P.

[0212] Consider the case of performing panoramic X-ray imaging by rotating the X-ray detection unit 44 along the second rotation orbit R2.

[0213] The case of targeting the imaging subject M(1) is shown in FIG. 23. The X-ray detection unit 44 passes through a position closer to the head P than in the case shown in FIG. 20 on the side of the head P. At this position, if the shoulder S(1) is below the chin tip or the like, there is a possibility that the X-ray detection unit 44 does not contact the shoulder S(1) even at the lateral position of the head P through which the X-ray detection unit 44 passes. In this case, panoramic X-ray imaging can be performed by rotating the X-ray detection unit 44 around the head P without vertically displacing the X-ray detection unit 44.

[0214] However, it is assumed that the passing position of the X-ray detection unit 44 on the side of the head P may be extremely close to the upper surface of the shoulder S(1). In such a case, in preparation for the occurrence of a contact state due to a slight movement of the subject M(1), it may be preferable to displace the X-ray detection unit 44 and the housing upward on the side of the head P. Also, the upper surface of the shoulder S(1) is shaped to face upward as it approaches the head P. For this reason, the closer the position of the side portion of the head P in the second turning orbit R2 is to the head P, the easier it is for the X-ray detection unit 44 to come into contact with the shoulder S(1). For this reason, depending on the set second turning orbit R2, there may be cases where it is preferable to displace the X-ray detection unit 44 upward on the side of the head P.

[0215] In such a case, as in the X-ray detection unit 44(H) shown in FIG. 24, it is advisable to perform panoramic X-ray imaging by vertically displacing the X-ray detection unit 44 so that the X-ray detection unit 44 is lower in front of the head P and higher on the side of the head P.

[0216] Regarding the subject M(3), as shown in FIG. 25, the X-ray detection unit 44 passes through a position near the side of the head P. When the subject M(3) has a physique such as angry shoulders, the height of the shoulder S(3) near the side of the head P according to the second turning orbit R2 is closer to the height of the chin tip of the head P than in the case of the subject M(1). For this reason, the X-ray detection unit 44 is more likely to come into contact with the shoulder S(3) on the side of the head P (see the X-ray detection unit 44(L) in FIG. 24).

[0217] Therefore, set the vertical displacement pattern as described in steps S24 and S25 above, and as described in step S27, vertically displace the X-ray detection unit 44 so that the X-ray detection unit 44 is lower in front of the head P and higher on the side of the head P (see the X-ray detection unit 44(H)). Thereby, while avoiding the X-ray detection unit 44 from coming into contact with the shoulder S, the X-ray detection unit 44 can be rotated along the second turning orbit R2. Thereby, while avoiding the X-ray detection unit 44 from coming into contact with the shoulder S(3), a panoramic X-ray image in which the front lower end of the dental arch Arc is captured can be generated.

[0218] In this way, by vertically displacing the X-ray detector 44, particularly by vertically displacing the X-ray detector 44 so that it becomes higher on the side of the head P and lower in front of the head P, it is possible to obtain a panoramic X-ray image in which the lower part of the front end of the dental arch Arc is captured while avoiding contact of the X-ray detector 44 with the shoulder S.

[0219] Normally, since the upper surface of the shoulder S is shaped to face upward as it approaches the head P, when the X-ray detector 44 rotates along the second rotation orbit R2 rather than the first rotation orbit R1, the X-ray detector 44 is likely to come into contact with the shoulder S. For this reason, when the X-ray detector 44 rotates along the second rotation orbit R2, it is advisable to vertically displace the X-ray detector 44. The second rotation orbit R2 in this case is an example of a vertical movement displacement orbit REL of the X-ray detector 44 during panoramic X-ray imaging where the displacement amount in the vertical direction is greater than zero.

[0220] Also, when the second rotation orbit R2 can be selected or adjusted, if an orbit close to the head P is selected or adjusted as the second rotation orbit R2, the X-ray detector 44 may be vertically displaced. Further, when an orbit closer to the head P is selected or adjusted as the second rotation orbit R2, the vertical displacement amount of the X-ray detector 44 may be increased. For example, as the initial setting values for both the first rotation orbit R1 and the second rotation orbit R2, the initial setting vertical displacement amount of the second rotation orbit R2 is set to be larger than the initial setting vertical displacement amount of the first rotation orbit R1.

[0221] In both the first turning orbit R1 and the second turning orbit R2, the X-ray detection unit 44 may be displaced vertically. In this case, in the second turning orbit R2 rather than the first turning orbit R1, the vertical displacement amount of the X-ray detection unit 44 may be set to be larger. Similar to the previous stage, for example, as initial setting values for both the first turning orbit R1 and the second turning orbit R2, the vertical displacement amount of the initial setting of the second turning orbit R2 is set to be larger than the vertical displacement amount of the initial setting of the first turning orbit R1. The vertical displacement amount of the second turning orbit R2 may be automatically set according to the vertical displacement amount of the first turning orbit R1. In this case, for example, it is conceivable to use, as the vertical displacement amount of the second turning orbit R2, the displacement amount obtained by multiplying the vertical displacement amount of the first turning orbit R1 by a multiple of a predetermined magnification.

[0222] When comparing and explaining the first turning orbit R1 and the second turning orbit R2 in relation to the same imaging subject M, when the X-ray detection unit 44 passes in front of the head P along the first turning orbit R1, there is no other human body part that becomes a contact target below the front of the head P. Therefore, the X-ray detection unit 44 can move without contacting the imaging subject M. Also, when the X-ray detection unit 44 passes by the side of the head P along the first turning orbit R1, the X-ray detection unit 44 passes through a location further away from the surface of the head P side than when it moves along the second turning orbit R2. Usually, the upper surface of the shoulder S has a shape that faces downward as it moves away from the head P. For this reason, as the X-ray detection unit 44 moves away from the head P side, the upper surface of the shoulder S is also located downward and is difficult to contact the shoulder S.

[0223] When the X-ray detection unit 44 turns along the second turning orbit R2, when the X-ray detection unit 44 passes in front of the head P, there is no other human body part that becomes a contact target below the front of the head P. Therefore, similar to the above, the X-ray detection unit 44 can move without contacting the imaging subject M. When the X-ray detection unit 44 passes by the side of the head P, the X-ray detection unit 44 passes through a position closer to the surface of the head P than when it moves along the first turning orbit R1. Usually, the upper surface of the shoulder S has a shape that faces upward as it approaches the head P. For this reason, the closer the X-ray detection unit 44 approaches the head P, the easier it is for the X-ray detection unit 44 to contact the shoulder S.

[0224] Here, there are individual differences in the positional relationship between the dental arch Arc and the shoulder S that are the subject of panoramic X-ray imaging at the head P. For example, when the subject M has a hunched shoulder and a short neck body type, etc., since the difference in the vertical position of the surface of the shoulder S relative to the height position of the dental arch Arc is small, the X-ray detection unit 44 is considered likely to come into contact with the shoulder S. Also, for example, when the subject M has a relaxed shoulder and a long neck body type, etc., the difference in the vertical position of the surface of the shoulder S relative to the height position of the dental arch Arc is larger than in the above case. Therefore, the X-ray detection unit 44 is considered difficult to come into contact with the shoulder S.

[0225] Therefore, for panoramic X-ray imaging using the first turning orbit R1, it is considered possible to perform it on subjects M with most body builds, whereas for panoramic X-ray imaging using the second turning orbit R2, cases where it can be performed and cases where it is difficult to perform are likely to occur depending on the body build.

[0226] As a response for the user, either a response of performing panoramic X-ray imaging without vertically displacing the X-ray detection unit 44 or a response of performing panoramic X-ray imaging with the X-ray detection unit 44 vertically displaced can be adopted.

[0227] In the former case, the user observes the body build of the subject M, or actually turns the X-ray detection unit 44 tentatively, etc., and when setting the second turning orbit R2, determines whether the X-ray detection unit 44 comes into contact with the subject M. Alternatively, based on the output result of the body build detection unit (imaging device 22), it may be determined whether the second turning orbit R2 is applicable. And if the second turning orbit R2 is applicable, the second turning orbit R2 is set (see steps S2, S3), and panoramic X-ray imaging using the second turning orbit R2 can be performed. If the second turning orbit R2 is difficult to apply, panoramic X-ray imaging using the first turning orbit R1 is performed.

[0228] In the latter case, the user sets a turning trajectory, for example, a second turning trajectory R2, along which the X-ray detection unit 44 can approach the head P within a range where contact with the head P can be avoided. Then, under the condition that the second turning trajectory R2 is set, a vertical displacement pattern for avoiding contact with the shoulder S is set. The X-ray detection unit 44 is vertically displaced according to the set vertical displacement pattern to perform panoramic X-ray imaging.

[0229] When the user makes the turning trajectory of the X-ray detection unit 44 approach the head P too much and it becomes difficult to avoid contact of the X-ray detection unit 44 with the shoulder S, the degree of approach of the X-ray detection unit 44 to the head P and the vertical displacement amount of the X-ray detection unit 44 may be set so as to achieve a good balance.

[0230] According to this X-ray imaging apparatus 200, by turning the X-ray detection unit 44 along the second turning trajectory R2 closer to the head P, the resolution of the panoramic X-ray image can be further improved.

[0231] Also, generally, in the second turning trajectory R2 closer to the head P, the necessity of vertically displacing the X-ray detection unit 44 becomes higher than that in the first turning trajectory R1, and the vertical displacement amount also tends to be large. Therefore, considering the case, physique, importance of high resolution, allowable range of vertical displacement in the panoramic X-ray image, etc. of the imaging subject M, the turning trajectory of the X-ray detection unit 44 and the vertical displacement amount of the X-ray detection unit 44 are set to easily obtain an appropriate panoramic X-ray image.

[0232] Also, if at least one of the first turning trajectory R1 and the second turning trajectory R2, particularly the second turning trajectory R2, is a trajectory that approaches within 10 cm from the surface of the head P in front of the head P, the resolution of the panoramic X-ray image, particularly the resolution in the anterior tooth region Pa, can be improved.

[0233] Also, if at least one of the first turning trajectory R1 and the second turning trajectory R2, particularly the second turning trajectory R2, is a trajectory that approaches within 10 cm from the surface of the head P in front of the head P throughout, the resolution of the panoramic X-ray image can be further improved throughout.

[0234] Further, as the second turning orbit R2, if a partial orbit in the front range of the front tooth region Pa is set to be closer to the surface of the head P than the partial orbits in other ranges, the X-ray detection unit 44 can be brought closer to the front tooth region Pa, and the resolution of the panoramic X-ray image representing the front tooth region can be further improved.

[0235] Also, as the second turning orbit R2, if an orbit is set in which the distance to the surface of the head P on the side of the head P is larger than the distance to the surface of the head P in front of the head P, the X-ray detection unit 44 can easily turn while avoiding contact with the shoulder S. Similarly, as the first turning orbit R1, if an orbit is set in which the distance to the surface of the head P on the side of the head P is larger than the distance to the surface of the head P in front of the head P, the X-ray detection unit 44 can easily turn while avoiding contact with the shoulder S.

[0236] <Modification Example> In the above second embodiment, an example has been described in which the second turning orbit information 204c that defines the second turning orbit R2 is preset and stored in the storage unit 104. The imaging control unit 202 may set the second turning orbit R2 for each individual according to the physical data of the individual of the imaging subject M.

[0237] FIG. 26 is a flowchart showing an example of the processing of the imaging control unit 202 according to this modification example. This flowchart will be mainly described with respect to the differences from the flowchart shown in FIG. 18. In this flowchart, step S23 in FIG. 18 is changed to step S23a and step S23b.

[0238] In step S23a and step S23b, the imaging device 22 is used as the head surface shape detection unit that detects the surface shape of the head P, and the second turning orbit R2 is set according to the detection result of the imaging device 22.

[0239] That is, in step S23a, the imaging device 22 images the head P and the shoulders S held by the subject holding unit 32. For example, the X-ray detection unit 44 may be rotated along a first turning orbit R1 that is difficult to contact the subject M, and the image data obtained by imaging the head P from a plurality of directions may be used as the detection result. The imaging data may include the shoulders S. Since the surface shape of the head P is included in this image data, the image data is an example of physical data including the physique related to the head P of the subject M.

[0240] In the next step S23b, a second turning orbit R2 is set based on the surface shape of the head P.

[0241] A more specific example of steps S23a and S23b will be described. First, the positional relationship between the imaging device 22 with respect to the swivel arm 40 and the X-ray detection unit 44 can be regarded as known information. Therefore, as shown in FIG. 27, based on the image data obtained by imaging the head P, head surface shape data representing the surface shape of the head P with respect to the X-ray detection unit 44 can be generated. The image data obtained by imaging the head P may be image data obtained by imaging the head P from a plurality of directions. For example, it can be a combination of image data obtained by imaging the head P from the front or the rear and image data obtained by imaging the head P from the left or the right. The horizontal cross-section of the head P represented by the head surface shape data may be the portion that extends the most widely among the horizontal cross-sections of the head P, for example, a horizontal cross-section passing through the top of the nose. In this head surface shape data, a second swivel orbit R2 where it is difficult for the X-ray detection unit 44 to contact the head P can be set. For example, a passing point passing through a predetermined distance of 10 cm or less from the front of the surface of the head P can be set, and a curve passing through the passing point can be set as the second swivel orbit R2. Also, for example, at a plurality of locations around the dental arch Arc in the head P, a plurality of passing points passing through a predetermined distance of 10 cm or less from the surface of the head P can be set, and a curve passing through the plurality of passing points can be set as the second swivel orbit R2. Further, for example, a plurality of candidate orbits of the second swivel orbit R2 are set in advance and stored in the storage unit 104, and based on the head surface shape data, among the plurality of candidate orbits, the one that can pass closest to the surface of the head P without the X-ray detection unit 44 contacting the head P may be set as the second swivel orbit R2. Also, for example, an initial candidate orbit of the second swivel orbit R2 is set in advance and stored in the storage unit 104, and the initial candidate orbit is sequentially enlarged or reduced (for example, orbits passing through positions closer to or farther from the head P by a predetermined distance (for example, 1 cm) with respect to the initial candidate orbit are sequentially set), and based on the head surface shape data, an orbit that can pass closest to the surface of the head P without the X-ray detection unit 44 contacting the head P is specified, and that orbit may be set as the second swivel orbit R2.

[0242] The first turning orbit R1 may also be set according to the detection result of the imaging device 22. However, since the second turning orbit R2 closer to the head surface is preferably determined by actual measurement using a highly reliable head surface shape detection unit, the second turning orbit R2 is set based at least on the surface shape of the head P.

[0243] The setting of the second turning orbit R2 according to the individual of the subject M to be photographed may be made based on X-ray image data obtained by previously photographing the subject M to be photographed, for example, cephalometric photographing data. Since the left and right parts of the head P are captured in the frontal cephalometric photographing data and the front part of the head P is captured in the lateral cephalometric photographing data, based on the cephalometric photographing data, the positions of the left and right parts and the front part of the head P can be discriminated, and in the same manner as above, the second turning orbit R2 can be set. The cephalometric photographing data is also an example of physical data. Since the surface shape of the head P is also captured in the cephalometric photographing data, the X-ray detector 45 that captures the cephalometric photographing data can be used as an example of the head surface shape detection unit.

[0244] In both the visible light image and the X-ray image, by performing image recognition processing such as edge extraction image processing, the surface or boundary of the head P can be automatically extracted. However, the designation of the surface or boundary of the head P may be made by the user's pointer designation or the like.

[0245] The device for detecting the surface shape of the head P as the head surface shape detection unit may be a portable terminal device 300 having an imaging device such as a smartphone or a tablet terminal device (see FIG. 2). The portable terminal device 300 captures an image in which the head P and the reference part in the X-ray imaging device 20 are captured, and by performing image processing or the like based on the captured image, the surface position of the head P in the X-ray imaging device 20 can be recognized. Thereby, in the same manner as above, the second turning orbit R2 and the like can be set for each individual.

[0246] Further, for example, a visible light sensor or a laser sensor for detecting the surface of the head P, particularly the front part and the side part, is incorporated in the swing arm 40, and the surface position of the head P, particularly the front part and the side part, may be detected based on the output of the sensor. Data including those detection results is an example of body size data. Based on those detection results, the surface position of the head P with respect to the swing arm 40 and the X-ray detection unit 44, particularly the front part and the side part, is specified, and thus, similarly to the above, the second swing orbit R2 can be set.

[0247] The second swing orbit R2 may be set individually according to the user's setting. For example, a plurality of candidate orbits of the second swing orbit R2 are set in advance and stored in the storage unit 104, and the user inputs a distinction between adult size and child size, or a distinction between S size, M size, and L size, so that a candidate orbit corresponding to the input size may be set as the second swing orbit R2.

[0248] Further, when the shoulder S of the imaging subject M is higher than the standard position, the second swing orbit R2 may be set to be more roundabout on the side of the head P.

[0249] When the X-ray detection unit 44 is swung along the second swing orbit R2 and the X-ray detection unit 44 contacts the shoulder S, as described above, the X-ray detection unit 44 is vertically displaced during the swing.

[0250] According to this modification, the imaging control unit 202 can set the second swing orbit R2 individually according to the body size data of the imaging subject M. Therefore, according to the body size of the individual, the X-ray detection unit 44 can be brought as close as possible to the head P to perform panoramic X-ray imaging, and a high-resolution panoramic X-ray image can be obtained.

[0251] In this case, by setting the second swing orbit R2 based on the detection result of the head surface shape detection unit such as the imaging device 22, the second swing orbit R2 can be easily set. Further, based on the detection result, the second swing orbit R2 that passes close to the surface of the head P can be easily set.

[0252] Further, as the second turning orbit R2, by setting an orbit passing through a position within 10 cm from the surface of the head P, the resolution of the panoramic X-ray image is further improved.

[0253] In this modification, an example in which the second turning orbit R2 is set individually for each individual has been described, but the first turning orbit R1 that turns at a position farther from the head P than the first turning orbit R1 may also be set individually for each individual in the same manner as described above.

[0254] The turning orbit R may be configured so that a user (technician, operator, operator) can arbitrarily set it, and the user may be able to change the turning orbit R based on the turning orbit information 204 stored in the storage unit 104 to set a new turning orbit R. In this case, when the X-ray detection unit 44 faces the side portion of the head P, an X-ray detection orbit may be set such that the displacement amount of the additional vertical movement to the X-ray detection unit 44 increases as the turning orbit R with respect to the side surface of the head P of the X-ray detection unit 44 approaches the side surface of the head P.

[0255] In setting the X-ray detection orbit for panoramic X-ray imaging of the X-ray imaging apparatuses 20 and 200, it may be possible to correspond to the relationship of the position of the shoulder S with respect to the head P, particularly the height relationship in the Z direction, according to the physique of each individual imaging subject M. As this correspondence, the X-ray imaging apparatuses 20 and 200 may be configured to be able to change the displacement amount of the additional vertical movement to the X-ray detection unit 44 by the vertical drive unit 82 according to the position of the shoulder S with respect to the head P for each physique of each individual imaging subject M.

[0256] The change in the displacement amount of the additional vertical movement may be made according to the reception of a user input operation corresponding to the position of the shoulder S with respect to the head P for each physique of each individual imaging subject M or according to the detection result by the imaging device 22 corresponding to the position of the shoulder S with respect to the head P for each physique of each individual imaging subject M. The reception of the input operation is performed, for example, through the imaging setting reception unit 110a.

[0257] {Modification} In addition, the components described in each of the above embodiments and each modification can be appropriately combined as long as they do not conflict with each other.

[0258] As described above, this specification and the drawings disclose the following aspects.

[0259] A first aspect includes an X-ray generation unit including an X-ray generator, an X-ray detection unit including an X-ray detector, a support unit that supports the X-ray generation unit and the X-ray detection unit so that the X-ray generation unit and the X-ray detection unit face each other, a drive mechanism that rotates at least the X-ray generation unit and the X-ray detection unit by driving the support unit, a displacement mechanism that adds a movement including a displacement component in a direction different from the rotation to the X-ray detection unit, a subject holding unit that holds a subject to be photographed, and a rotation control unit that controls the driving of the support unit by the drive mechanism and the addition of the movement to the X-ray detection unit by the displacement mechanism so as to perform panoramic X-ray photography by rotating around the head of the subject to be photographed held by the subject holding unit with the head of the subject to be photographed held by the subject holding unit positioned between the X-ray generation unit and the X-ray detection unit. The rotation control unit controls the drive mechanism and the displacement mechanism so as to add a movement that avoids contact with the shoulder of the subject to be photographed to the X-ray detection unit during the rotation of the X-ray generation unit and the X-ray detection unit by the drive mechanism during the panoramic X-ray photography. It is a panoramic X-ray imaging device.

[0260] According to this panoramic X-ray imaging device, when the X-ray generation unit and the X-ray detection unit rotate around the head positioned between them, a movement that avoids contact with the shoulder of the subject to be photographed is added to the X-ray detection unit. Therefore, while suppressing the X-ray detection unit from hitting the shoulder, the X-ray detection unit can be brought as close as possible to the head of the subject to be photographed. If the X-ray detection unit can be brought as close as possible to the head of the subject to be photographed, the resolution of the panoramic X-ray image can be improved.

[0261] A second aspect is the panoramic X-ray imaging apparatus according to the first aspect, wherein the displacement mechanism includes a vertical displacement mechanism that vertically displaces the X-ray detection unit with respect to the head, and the turning control unit is configured such that a lower end position of the X-ray detection unit passing through a side of the head is located higher than a lower end position of the X-ray detection unit passing through a front of the head, and adds vertical movement to the X-ray detection unit by the vertical displacement mechanism.

[0262] In this case, when the X-ray detection unit passes through the front of the head, even if the X-ray detection unit is located on the lower side, it is difficult for the X-ray detection unit to come into contact with the human body, so the X-ray detection unit can be brought closer to the head. When the X-ray detection unit passes through the side of the head, since the X-ray detection unit is located on the upper side, the X-ray detection unit can be brought closer to the head while suppressing contact with the shoulder. Therefore, it is possible to improve the resolution of the panoramic X-ray image while suppressing the X-ray detection unit from hitting the shoulder.

[0263] A third aspect is the panoramic X-ray imaging apparatus according to the second aspect, wherein the vertical displacement mechanism is a mechanism that vertically moves the support unit with respect to the head.

[0264] Thereby, by vertically moving the support unit, the X-ray generation unit and the X-ray detection unit can be vertically moved together.

[0265] A fourth aspect is the panoramic X-ray imaging apparatus according to the second or third aspect, further comprising a physique detection unit that detects the physique of the subject, and the turning control unit controls the driving of the vertical displacement mechanism according to a detection result by the physique detection unit.

[0266] According to the fourth aspect, it is possible to control the operation of the vertical displacement mechanism according to the physique of the subject to suppress hitting the shoulder.

[0267] The fifth aspect is the panoramic X-ray imaging apparatus according to the fourth aspect, wherein the turning control unit determines whether vertical movement is necessary to avoid contact with the shoulders according to the detection result by the body detection unit, and when it is determined to be necessary, adds vertical movement to the X-ray detection unit by the vertical displacement mechanism.

[0268] According to the fifth aspect, depending on the body build, a panoramic X-ray image obtained without vertically displacing the X-ray detection unit can be obtained.

[0269] The sixth aspect is the panoramic X-ray imaging apparatus according to the fourth or fifth aspect, wherein the turning control unit determines the amount of vertical displacement to avoid contact with the shoulders according to the detection result by the body detection unit, and adds vertical movement to the X-ray detection unit by the vertical displacement mechanism according to the determined amount of vertical displacement.

[0270] According to the sixth aspect, panoramic X-ray imaging can be performed with an appropriate amount of vertical displacement according to the body build.

[0271] The seventh aspect is the panoramic X-ray imaging apparatus according to any one of the first to sixth aspects, wherein the drive mechanism includes a turning mechanism that turns the X-ray generator and the X-ray detector, and a two-dimensional movement mechanism that moves the X-ray generator and the X-ray detector in two-dimensional directions along the turning plane of the X-ray generator and the X-ray detector by the turning mechanism.

[0272] According to the seventh aspect, when the X-ray generator and the X-ray detector are turned by the turning mechanism, the turning orbits of the X-ray generator and the X-ray detector can be changed by moving the X-ray generator and the X-ray detector in two-dimensional directions along the turning plane by the two-dimensional movement mechanism.

[0273] The eighth aspect is the panoramic X-ray imaging apparatus according to the seventh aspect, wherein the turning mechanism is a turning mechanism that turns the support portion around the turning axis of the turning axis portion, and the two-dimensional movement mechanism is a turning axis movement mechanism that moves the turning axis portion in a direction intersecting the axial direction of the turning axis portion.

[0274] According to the eighth aspect, in synchronization with the turning mechanism turning the support portion, the turning axis moving mechanism moves the turning axis portion to cause the support portion to perform a combined motion, thereby changing the turning trajectories of the X-ray generating unit and the X-ray detecting unit.

[0275] The ninth aspect is a panoramic X-ray imaging apparatus according to the seventh or eighth aspect, wherein the turning control unit is configured to be able to set a first turning trajectory and a second turning trajectory of the X-ray detecting unit in the panoramic X-ray imaging, and the second turning trajectory is a trajectory closer to the surface of the head than the first turning trajectory in front of the head.

[0276] Thereby, by turning the X-ray detecting unit along the second turning trajectory closer to the head, the resolution of the panoramic X-ray image can be further improved.

[0277] The tenth aspect is a panoramic X-ray imaging apparatus according to any one of the first to ninth aspects, wherein the turning control unit sets the turning trajectory of the X-ray detecting unit in the panoramic X-ray imaging to pass through a position within 10 cm from the surface of the head in front of the head.

[0278] In this way, by turning the X-ray detecting unit along a turning trajectory closer to within 10 cm from the surface of the head in front of the head, the resolution of the panoramic X-ray image can be further improved.

[0279] The eleventh aspect is a panoramic X-ray imaging apparatus according to the tenth aspect, wherein the turning control unit sets the turning trajectory of the X-ray detecting unit in the panoramic X-ray imaging to pass through a position within 10 cm from the surface of the head throughout.

[0280] Thereby, an X-ray detecting unit can be brought closer to within 10 cm from the surface of the head to obtain a clearer panoramic X-ray image.

[0281] The first turning orbit R1 is as shown in Fig. 17(a), and it may be possible to selectively switch between the first turning orbit R1 shown in Fig. 17(a) and the second turning orbit R2 shown in Fig. 9. The second turning orbit R2 is set as an orbit closer to the head surface than the first turning orbit R1 in front of the head P (at least in front of the center in the left-right direction of the head P). For this reason, the X-ray detection unit 44 that turns along the second turning orbit R2 can detect X-rays while approaching the anterior tooth region of the dental arch Arc, which is the region of interest.

[0282] The second turning orbit R2 has a higher degree of proximity to the head surface of the X-ray detection unit 44 than the first turning orbit R1 in front of the head P. Also, the second turning orbit R2 has a higher front proximity ratio and a lower side proximity ratio than the first turning orbit R1. Under this condition, further, the height difference FS2 of the second turning orbit R2 may be set larger than the height difference FS1 of the first turning orbit R1. Thereby, for example, it is possible to cope even when the degree of the angry shoulder of the subject to be imaged is stronger.

[0283] Also, in a configuration where the first turning orbit R1 shown in Fig. 9 and the second turning orbit R2 shown in Fig. 26 can be selectively switched, another second turning orbit R2 may also be made selectable. The said another second turning orbit R2 may be, for example, the second turning orbit R2 shown in Fig. 17(b), and the height difference of the second turning orbit R2 shown in Fig. 17(b) may be set to be larger than that of other turning orbits. Thereby, the valuation of the approach to the head P of the subject to be imaged can be enhanced.

[0284] Regarding the degree of proximity of the X-ray detection unit 44 to the head surface, at least a part of the entire area of the second turning orbit R2 may be made larger than the first turning orbit R1, and the remaining area may be set to be equal to or smaller than the first turning orbit.

[0285] The above descriptions are all illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless modifications not illustrated can be assumed without departing from the scope of the present invention.

Explanation of Reference Numerals

[0286] 20. 200 X-ray imaging apparatus 22 Imaging device 30 Imaging main body part 32 Subject holding part 40 Swivel arm 42 X-ray generation part 43 X-ray generator 44 X-ray detection part 45 X-ray detector 46 Housing 47 X-ray detector vertical movement drive part 60 Drive mechanism 62 Swivel mechanism 70 Swivel axis movement mechanism 82 Vertical drive part 100, 202 Imaging control part 102 Processor 102b Vertical displacement setting part 102g Orbit setting part 104 Memory part 104a, 204a Imaging program 104b Vertical displacement information 104b1, 104b2, 104b3 Vertical displacement patterns 204b First swivel orbit information 204c Second swivel orbit information M Subject to be imaged P Head R Swivel orbit R1 First swivel orbit R2 Second swivel orbit S Shoulder X1 Swivel axis (central axis)

Claims

1. an X-ray generating unit including an X-ray generator; an X-ray detection unit including an X-ray detector; a support unit that supports the X-ray generation unit and the X-ray detection unit so that the X-ray generation unit and the X-ray detection unit face each other; a drive mechanism that drives the support unit to rotate at least the X-ray generation unit and the X-ray detection unit; a displacement mechanism that applies a movement including a displacement component in a direction different from the rotation to the X-ray detection unit; a subject holding unit that holds a subject to be imaged; and a rotation control unit that controls the driving mechanism to drive the support unit and the displacement mechanism to apply movement to the X-ray detection unit, so that panoramic X-ray imaging is performed by rotating around the head of the subject to be imaged while the head is positioned between the X-ray generation unit and the X-ray detection unit. Equipped with a panoramic X-ray imaging device, wherein the rotation control unit controls the drive mechanism and the displacement mechanism so as to apply a movement to the X-ray detection unit to avoid contact with a shoulder of the imaging subject during rotation of the X-ray generation unit and the X-ray detection unit during the panoramic X-ray imaging, the displacement mechanism includes a vertical displacement mechanism that displaces the X-ray detection unit vertically relative to the head, the rotation control unit is capable of applying vertical movement to the X-ray detection unit by the vertical displacement mechanism so that a lower end position of the X-ray detection unit passing beside the head is positioned higher than a lower end position of the X-ray detection unit passing in front of the head, the drive mechanism further includes a rotation mechanism that rotates the X-ray generation unit and the X-ray detection unit, and a two-dimensional movement mechanism that moves the X-ray generation unit and the X-ray detection unit in two-dimensional directions along rotation planes of the X-ray generation unit and the X-ray detection unit by the rotation mechanism, the rotation control unit is configured to be able to set a first rotation orbit and a second rotation orbit of the X-ray detection unit in the panoramic X-ray imaging; the second rotation trajectory is a trajectory that is closer to a surface of the head than the first rotation trajectory on a side of the head, a panoramic X-ray imaging device, wherein the difference in height between the X-ray detection unit and the head when the X-ray detection unit is located in front of the head and the X-ray detection unit and the head when the X-ray detection unit is located to the side of the head is defined as a difference in height, and the difference in height of the second rotation orbit is greater than the difference in height of the first rotation orbit.

2. A panoramic X-ray imaging device according to claim 1, The vertical displacement mechanism is a mechanism for moving the support part up and down relative to the head.

3. A panoramic X-ray imaging device according to claim 1 or claim 2, further comprising a physique detection unit for detecting the physique of the person to be photographed, The rotation control unit controls the driving of the vertical displacement mechanism in accordance with the detection result by the physique detection unit.

4. A panoramic X-ray imaging device according to claim 3, The rotation control unit determines whether or not vertical movement is necessary to avoid contact with the shoulder, based on the detection result by the physique detection unit, and when it is determined that vertical movement is necessary, causes the vertical displacement mechanism to add vertical movement to the X-ray detection unit.

5. A panoramic X-ray imaging device according to claim 3, the rotation control unit determines an amount of vertical displacement to avoid contact with the shoulder according to the detection result by the physique detection unit, and causes the vertical displacement mechanism to apply vertical movement to the X-ray detection unit according to the determined amount of vertical displacement.

6. A panoramic X-ray imaging device according to claim 1 or claim 2, a panoramic X-ray imaging device, wherein the rotation mechanism is a rotation mechanism that rotates the support part around the rotation axis of a rotation shaft part, and the two-dimensional movement mechanism is a rotation axis movement mechanism that moves the rotation shaft part in a direction intersecting with the axial direction of the rotation shaft part.

7. A panoramic X-ray imaging device according to claim 1, A panoramic X-ray imaging apparatus, wherein the second rotational orbit is an orbit that is closer to the surface of the head in front of the head than the first rotational orbit.

8. 3. The panoramic X-ray imaging apparatus according to claim 1, a rotation control unit that sets a rotation path of the X-ray detection unit during the panoramic X-ray imaging so that the rotation path passes through a position in front of the head within 10 cm from the surface of the head;

9. A panoramic X-ray imaging apparatus according to claim 8, The panoramic X-ray imaging apparatus, wherein the rotation control unit sets the rotation path of the X-ray detection unit during the panoramic X-ray imaging so that the entire path passes through a position within 10 cm from the surface of the head.

10. A panoramic X-ray imaging apparatus according to claim 1 or claim 2, A panoramic X-ray imaging apparatus, wherein the height difference of the first rotation orbit is zero.

Images