JP7458613B2 - Panoramic X-ray imaging device - Google Patents

Description

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

Patent Document 1 discloses that a shoulder contact detection means such as a camera detects the possibility of a patient's shoulder contact, and when a shoulder contact is detected, a shoulder contact warning is issued.

Patent Document 2 discloses that when performing panoramic X-ray photography, in order to suppress the X-ray generator from coming into contact with the head, the passage of the X-ray detector is adjusted according to the size of the subject's head. Changing the route is disclosed.

JP 2009-136363 A International Publication No. 2019/131859

Here, there is a need to improve the resolution of panoramic images (the ability to express details in the area to be photographed). The resolution of the panoramic image improves as the X-ray detector is closer to the head, which is the region to be imaged.

Patent Documents 1 and 2 disclose configurations that aim to avoid contact with the patient's shoulders or head, and discuss ways to bring the X-ray detector closer to the head to improve the resolution of panoramic images. lack.

Therefore, an object of the present disclosure is to provide a panoramic X-ray imaging apparatus that can improve the resolution of panoramic images.

In order to solve the above problems, a panoramic X-ray imaging apparatus includes an X-ray generation section including an X-ray generator, an X-ray detection section including an X-ray detector, and a combination of the X-ray generation section and the X-ray detection section. a support section that supports the X-ray generation section and the X-ray detection section so that they face each other, a drive mechanism that drives the support section, a subject holding section that holds a person to be photographed, and the X-ray generation section. and the X-ray detection section are configured to detect the area around the head of the person to be photographed, which is held by the subject holding section, with the head of the subject held by the object holding section positioned between the X-ray generation section and the X-ray detection section. a rotation control section that controls the operation of the support section by the drive mechanism so as to perform panoramic X-ray photography by rotating the X-ray detection section for the same person to be imaged; is configured such that a first rotation trajectory and a second rotation trajectory can be set as a panoramic rotation trajectory, and the second rotation trajectory is closer to the head than the first rotation trajectory in front and to the side of the head. The orbit is said to be close to the surface of

According to this panoramic X-ray imaging device, the resolution of panoramic images can be improved.

1 is a perspective view showing an X-ray imaging apparatus according to a first embodiment. FIG. 2 is a partially sectional side view showing the X-ray imaging apparatus. FIG. 3 is an explanatory diagram showing an X-ray beam shape adjustment section. FIG. 3 is an explanatory diagram showing an X-ray beam shape adjustment section. FIG. 3 is a partially cutaway plan view showing the pivot axis moving mechanism. FIG. 3 is a partially cutaway front view showing the pivot axis moving mechanism. FIG. 2 is a block diagram showing an example of the electrical configuration of an X-ray imaging apparatus. 7 is a flowchart illustrating an example of processing by a photographing control unit. It is an explanatory view showing an example of a first turning orbit. It is an explanatory view showing an example of the 2nd turning orbit. FIG. 2 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging. FIG. 2 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging. 10 is a flowchart showing an example of processing by an imaging control unit according to a modified example. 5 is an explanatory diagram showing an example of head surface shape data representing the surface shape of the head relative to the X-ray detection unit; FIG. FIG. 11 is a block diagram showing an example of the electrical configuration of an X-ray imaging apparatus according to a second embodiment. 7 is a flowchart illustrating an example of processing by a photographing control unit. It is a figure which shows an example of a vertical displacement pattern. FIG. 2 is an explanatory diagram showing an example of the physique of a plurality of subjects to be photographed. 11 is an explanatory diagram showing the positional relationship of the X-ray detection unit and the housing with respect to the subject during panoramic imaging using the first rotation orbit. FIG. FIG. 6 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging using the first orbit. 11 is an explanatory diagram showing the positional relationship of the X-ray detection unit and the housing with respect to the subject during panoramic imaging using the first rotation orbit. FIG. FIG. 7 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging using a second orbit. FIG. 7 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging using a second orbit. FIG. 7 is an explanatory diagram showing the positional relationship between the X-ray detection unit and the housing with respect to the person to be imaged during panoramic imaging using a second orbit. It is an explanatory view showing an example of an image for detecting the position of a shoulder. It is an explanatory view showing an example of a second turning orbit.

{First embodiment}
The panoramic X-ray imaging apparatus according to the first embodiment will be described below.

<Overall configuration>
The overall configuration of an X-ray imaging device, which is an example of a panoramic X-ray imaging device, will be described. FIG. 1 is a perspective view showing an X-ray imaging apparatus 20. As shown in FIG. In FIG. 1, a part of the configuration is shown as functional blocks. FIG. 2 is a partially sectional side view showing the X-ray imaging apparatus 20. As shown in FIG.

Note that the direction is defined for convenience of explanation.

The XYZ orthogonal coordinate system is an orthogonal coordinate system defined in the three-dimensional space in which the imaging main body section 30 is installed. The Z-axis direction is parallel to the axial direction of a mechanical turning axis X1, which will be described later. In the present embodiment, a direction parallel to the axial direction of the rotation axis X1 on the mechanism and a direction of movement by the vertical drive section 82, which will be described later, match as the Z-axis direction. The direction perpendicular to the Z-axis direction is the Y-axis direction, and the direction perpendicular to both the Z-axis direction and the Y-axis direction is the X-axis direction. The front-rear direction of the head P held by the subject holding section 32 is defined as the Y-axis direction, and the left-right direction of the head is defined as the X-axis direction. In this application, the Z-axis direction is sometimes 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 viewing direction, for example, the viewing direction from the -Z side to the +Z side is called +Z direction viewing, and the viewing direction from the -○ (○ is either X, Z, or Y) side to the +○ side, or the viewing direction. The line of sight direction parallel to is defined as "viewing in the +○ direction", and the line of sight direction looking from the +○ side to the -○ side or the line of sight direction parallel to that line of sight direction is defined as "viewing in the -○ direction". When simply stating "viewing in ○ direction", it may be viewed in +○ direction or -○ direction. A two-dimensional surface that extends in the X and Y directions is called an ” is sometimes expressed.

The direction from the head P toward the base 80B, that is, the lower side, is defined as the -Z side, and conversely, the direction that goes away from the head P from the base 80B, that is, the upper side, is defined as the +Z side. The front of the head P is the +Y side, and the back 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 axis direction is illustrated in FIGS. 1 and 2.

The X-ray imaging device 20 includes, for example, an imaging main body 30 and an X-ray image processing device 180 (also simply referred to as the image processing device 180). The imaging main unit 30 is configured to be able to perform panoramic X-ray imaging. In addition to panoramic X-rays, the imaging main unit 30 may be configured to be able to perform, for example, at least one of simple transmission X-ray imaging, X-ray CT (Computed Tomography) imaging, and cephalometric imaging. The imaging main unit 30 performs X-ray imaging such as panoramic X-ray imaging and collects X-ray imaging data (also referred to as projection data). The collected X-ray imaging data is processed by the X-ray image processing device 180, which is a device that generates various X-ray images (specifically, X-ray CT imaging images, panoramic imaging images, cephalometric imaging images, etc.). be. In this example, the X-ray image processing device 180 processes X-ray imaging data collected through 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 a dental arch is continuously expressed by X-ray transmission images in a direction orthogonal to the dental arch. Depending on the part of the dental arch, orthogonality may be intentionally avoided to avoid capturing other hard tissues such as the jawbone. In such a panoramic X-ray image, adjacent teeth are shown without overlapping as much as possible. The X-ray imaging device 20 is configured as a device that collects X-ray imaging data, and the X-ray image processing device 180 may be omitted. The X-ray imaging device 20 may be configured to include only some of the functions of the X-ray image processing device 180.

The imaging main body 30 includes an X-ray generating unit 42, an X-ray detecting unit 44, a rotating arm 40 which is an example of a support unit, a driving mechanism 60, a subject holding unit 32, and an imaging control unit 100.

The X-ray generator 42 includes an X-ray generator 43 that generates X-rays. The X-ray detector 44 includes an X-ray detector 45 that detects X-rays. The rotating arm 40 supports the X-ray generating section 42 and the X-ray detecting section 44 so that the X-ray generating section 42 and the X-ray detecting section 44 face each other. The drive mechanism 60 drives the swing arm 40 . The drive is, for example, a turning drive. The drive mechanism 60 rotates at least the X-ray generating section 42 and the X-ray detecting section 44 by driving the rotating arm 40 . The subject holding unit 32 holds the person M to be photographed. Under the control of the imaging control unit 100, the head P of the person to be photographed M held by the subject holding unit 32 is positioned between the X-ray generation unit 42 and the X-ray detection unit 44, and the drive mechanism 60 By driving the swing arm 40, the drive mechanism 60 swings the swing arm 40 so that the X-ray generation section 42 and the X-ray detection section 44 swing around the head P to perform panoramic X-ray photography. Movement by the vertical drive unit 82 may be added to the movement of the X-ray detection unit 44. The subject holding section 32 is preferably positioned so as to restrict the movement of the head P of the person to be imaged during X-ray imaging, and preferably to be fixed.

The configuration of each part will be explained in more detail.

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

The X-ray generator 42 includes an X-ray generator 43 and an X-ray beam shape adjuster 50. In this embodiment, the X-ray generator 42 further includes a housing 41 that houses an X-ray generator 43 and an X-ray beam shape adjuster 50. The housing 41 includes a bottom and a peripheral wall that surrounds a space above the bottom. The housing 41 is supported by one end of the swing arm 40 so as to protrude downward.

The X-ray generator 43 includes an X-ray tube that is an X-ray source that generates 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. Control of the X-ray generator 43 (specifically, control of the amount of voltage and/or amount of current) is performed by the irradiation control section 102d of the imaging control section 100.

The X-ray beam shape adjustment section 50 regulates 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 purpose of imaging. In other words, the X-ray beam shape adjustment unit 50 controls the X-ray irradiation range for the person (subject) M to be imaged. The X-ray beam shape adjustment section 50 is controlled by the irradiation control section 102d.

An example of the configuration of the X-ray beam shape adjustment section 50 will be described with reference to FIGS. 3 and 4. The X-ray beam shape adjustment unit 50 includes two shielding members 52A, a shielding member driving unit 53A that opens and closes the two shielding members 52A, two shielding members 52B, and a shielding member drive unit 53A that opens and closes the two shielding members 52B. and a shielding member driving section 53B that is driven. In FIG. 5, the shielding members 52A, 52B and the parts (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 imaginary lines (two points). (dashed line).

The shielding members 52A and 52B are made of a material (such as lead) that absorbs X-rays, and are formed into rectangular plate shapes.

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

The shielding member drive unit 53A drives the two shielding members 52A toward and away from each other along the vertical direction. For example, the shielding member drive 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, for example, a threaded 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 control 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 shaft 53A2.

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

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

Among the four shielding members 52A and 52B, the other two shielding members 52B are located at different positions from the two shielding members 52A in the direction of emission of X-rays from the X-ray generator 43. They are provided at the left and right positions on the front side of the exit port. The opposing sides of the two shielding members 52B are along the vertical direction.

The shielding member drive unit 53B drives the two shielding members 52B toward and away from each other along the left-right direction. The shielding member driving section 53B and the shielding member 52B may have the same structure as the shielding member driving section 53A and the shielding member 52A, with the only difference being the drive/movement direction. may differ by 90° around the axis of the irradiation. Then, the two shielding members 52B are individually driven to move in the left-right direction by clockwise or counterclockwise rotational driving of the two motors 53B3.

In addition, as the shielding member drive parts 53A and 53B, a linear motor mechanism, a rack and pinion mechanism, a mechanism using a belt and a pulley, etc. may be used.

In this example, the X-ray beam is The shape of the beam, the position of the irradiation target, etc. are adjusted.

For example, when the two opposing inner sides of the two shielding members 52A, the top and bottom, are wide open, and the two opposing inner sides of the two shielding members 52B, the left and right, are wide open, 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, opening 55H1, and is formed into an X-ray cone beam that spreads out in the shape of a regular square pyramid. Such an X-ray cone beam is used, for example, for CT imaging.

For example, in a state where the two opposing upper and lower inner sides of the two shielding members 52A are wide open, and the two opposing left and right inner sides of the two shielding members 52B are small open, the elongated opening 55H2 is formed (see Figure 4). The X-ray beam emitted from the X-ray generator 43 passes through the vertically elongated slit-shaped opening 55H2, thereby forming an X-ray slit beam that spreads vertically in the shape of a long truncated pyramid. Such an X-ray slit beam is used, for example, for panoramic X-ray photography.

By moving the two shielding members 52B in the same direction, for example, to the right, while maintaining the shape of the opening 55H2, the irradiation destination of the X-ray slit beam can be scanned from the left to the right. Also, by moving the two shielding members 52B in the same direction, for example, upward, while maintaining the shape of the opening 55H2, the irradiation destination of the X-ray slit beam can be moved from the bottom to the top.

For example, during panoramic X-ray photography, the X-ray beam shape adjustment unit 50 allows the center beam CB, which is the center of the X-ray beam, to adjust the X-ray beam irradiated from the X-ray generator 43 to the body of the person M to be photographed. It is possible to form an X-ray slit beam that enters upward from obliquely below the axis (vertical direction) 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, the X-ray beam enters the subject M horizontally from below and upward, thereby reducing shadows caused by the hard palate, angle of the mandible, vertebrae, etc. on the panoramic image. It will be done. In this way, making the X-ray beam enter the person M to be photographed in an upward direction from obliquely below may be referred to as oblique launch irradiation.

Note that when performing panoramic X-ray photography, it is not essential that the X-ray beam enters the person M to be imaged horizontally from below and upward; for example, the X-ray beam The light may also be incident along the horizontal direction.

The X-ray beam shape adjustment section may have other configurations. For example, the X-ray beam shape adjustment section may include two shielding members formed in an L-shaped plate shape, and an opening may be formed by a combination of edges forming inner corner portions of the two shielding members. In this case, the two shielding members are preferably 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. By moving and driving the two shielding members by the mechanism, the shape of the opening is adjusted in the same manner as above. Furthermore, the X-ray beam shape adjustment section may include a single shielding member in which one or more apertures are formed. In this case, if the shielding member is moved and driven by the linear movement mechanism, the position of the opening can be moved and the irradiation destination of the X-ray beam can be moved. Further, a plurality of apertures can be selectively opposed to the exit aperture of the X-ray generating section 42.

As shown in FIGS. 1 and 2, the X-ray detection section 44 includes an X-ray detector 45 and an X-ray detector vertical movement drive section 47. The X-ray detector 45 detects the X-ray beam emitted from the X-ray generator 42. The X-ray detector 45 may be configured with a flat panel detector (FPD) having a detection surface that spreads in a planar manner, an X-ray fluorescence intensifier (I.I.: Image Intensifier), or the like.

A plurality of detection elements arranged on the detection surface of the X-ray detector 45 convert the intensity of incident X-rays into electrical signals. The electrical signal is then 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.

In this embodiment, the X-ray detector 44 includes a housing 46 that houses an X-ray detector 45. The X-ray detector 45 is provided inside the housing 46 with a detection surface facing the X-ray generating section 42 . The detection surface of the X-ray detector 45 is irradiated with the X-ray beam emitted from the X-ray generator 42 . The housing 46 accommodates the X-ray detector 45 and the X-ray detector vertical movement drive section 47, and is supported by the other end of the swing arm 40.

The X-ray detector vertical movement drive section 47 moves the X-ray detector 45 in the vertical direction (Z-axis direction) with respect to the rotating arm 40. The X-ray detector vertical movement drive section 47 includes a motor 47a, a ball screw 47b, and a nut section 47c. The motor 47a rotates a ball screw 47b extending in the Z-axis direction around the Z-axis. The nut portion 47c is screwed onto the ball screw 47b, and is attached to the back surface of the X-ray detector 45 on the opposite side from the detection surface so as to be unrotatable with respect to the X-ray detector 45. The X-ray detector 45 may be guided by a rail (not shown) to move in the Z-axis direction while facing the X-ray generating section 42 side.

The motor 47a is controlled by the X-ray detection unit drive control unit 102e. Based on the control signal from the X-ray detector drive control section 102e, the motor 47a rotates the ball screw 47b, thereby moving the nut section 47c and the X-ray detector 45 in the Z-axis direction.

The housing 46 includes a cylindrical portion 46a that extends downward from the other end of the pivot arm 40 and opens downward, and an outer housing 46b that opens upward and is placed over the outside of the cylindrical portion 46a.

The motor 47a is fixed to the cylinder portion 46a. The outer housing 46b is biased upward by a spring portion 46d that is provided to vertically connect the rotating arm 40 or the cylinder portion 46a to the outer housing 46b. The lower end of the X-ray detector 45 can abut against the inside of the bottom surface of the outer housing 46b.

When the X-ray detector vertical movement drive section 47 moves the X-ray detector 45 downward, the X-ray detector 45 hits the bottom surface of the outer casing 46b and pushes the outer casing 46b downward. At this time, the spring portion 46d expands elastically, and elastic restoring force is accumulated in the spring portion 46d. Therefore, when the X-ray detector vertical movement driving section 47 moves the X-ray detector 45 upward, the outer housing 46b is pulled upward by the elastic restoring force of the spring section 46d. As a result, the outer casing 46b rises while contacting the X-ray detector 45 so as to follow the rising X-ray detector 45.

Note that the configuration in which the X-ray detection unit 44 is moved up and down with respect to the rotating arm 40 may be omitted.

By moving the outer casing 46b up and down with respect to the inner cylindrical portion 46a in accordance with the height position of the X-ray detector 45, the casing 46 expands and contracts in the vertical direction. By expanding and contracting the housing 46 in this manner, the X-ray detector 45 whose position in the height direction changes can be appropriately protected. Further, since the housing 46 is placed at the highest possible position by the spring portion 46d, the housing 46 is less likely to come into contact with the person M to be photographed during X-ray imaging. That is, the cylinder part 46a, the outer housing 46b, the spring part 46d, the X-ray detector vertical movement drive part 47, and the X-ray detector 45 are connected to the bottom of the X-ray detector 44 and the X-ray detector 45 itself located on the bottom side. An X-ray detection section expansion/contraction mechanism is formed that expands and contracts the X-ray detection section 44 in the Z direction by guiding and driving the movement of the X-ray detection section 44 in the vertical direction. The X-ray detector expansion/contraction mechanism also serves as an X-ray detector bottom position changing mechanism that changes the Z-direction position of the bottom of the X-ray detector 44 and the X-ray detector 45 itself located on the bottom side with respect to the rotating arm 40. Can function.

In this embodiment, when the X-ray detector 45 is placed at the highest position (that is, when the outer housing 46b is placed at the highest position), the lowermost end of the outer housing 46b (that is, the housing 46 The lowermost end of the housing 41 of the X-ray generating section 42 may be located at a lower position than the lowermost end of the housing 41 of the X-ray generating section 42 . That is, in this case, no matter what height the X-ray detector 45 is placed, the lowest end of the housing 46 is at a lower position than the lowest end of the housing 41.

When the X-ray beam is irradiated obliquely upward, the X-ray detector 45 can be positioned upward in accordance with the position of the irradiation destination. This allows the lower end of the outer housing 46b to be rotated to the highest possible position when performing panoramic X-ray photography with oblique irradiation. It is not essential to move the X-ray detection unit 44 and the housing 46 up and down in accordance with the irradiation destination of the X-ray beam. For example, if the detection surface of the X-ray detection unit 44 is large enough to detect the X-ray beam regardless of the irradiation destination of the X-ray beam, the X-ray detection unit 44 does not need to move up and down. Of course, if the irradiation direction of the X-ray beam is not changed up and down, the X-ray detection unit 44 and the housing 46 do not need to move up and down.

The rotating arm 40 that supports the X-ray generating unit 42 and the X-ray detecting unit 44 is supported on the upper frame 95 via the drive mechanism 60.

The upper frame 95 is supported by the support column 80. The support column 80 is supported in a standing state relative to the floor, for example, by a base 80B that extends horizontally relative to the floor. In this embodiment, the base end of the upper frame 95 is supported by the support 80 in a cantilevered manner, and the distal end of the upper frame 95 extends outward from the support 80 in the horizontal direction. . A pivot shaft portion 96 extending in the Z-axis direction is provided at the tip of the upper frame 95. A lower end portion of the pivot shaft portion 96 is connected to an intermediate portion of the pivot arm 40 between the X-ray generation portion 42 and the X-ray detection portion 44 . Thereby, the swing arm 40 is supported in a suspended state by the upper frame 95 via the swing shaft portion 96.

The drive mechanism 60 is a device that drives the swing arm 40 so that the X-ray generator 42 and the X-ray detector 44 swing around the head P of the person M to be imaged. The drive mechanism 60 can drive the rotating arm 40 so as to change at least the orbit of the X-ray detector 44 .

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 shaft portion 96, that is, around the turning axis. The shaft moving mechanism 70 moves the pivot shaft portion 96 in a direction intersecting (here, orthogonal to) the axial direction of the pivot shaft portion 96 .

More specifically, as shown in FIG. 6 , the swing arm 40 is rotatably supported by the lower end of the swing shaft 96 around the central axis of the swing shaft 96 . A bearing 97 may be interposed between the pivot shaft portion 96 and the pivot arm 40, and the pivot arm 40 may be configured to rotate smoothly with respect to the pivot shaft portion 96.

A rotating mechanism 62 is provided inside the rotating 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 rotational direction and direction of the rotation 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 rotating motor 63 and an annular member fixed to the lower end of the rotating shaft portion 96 . In this case, the pivot shaft portion 96 is fixed to the upper frame 95 so as not to rotate. As rotational force is transmitted to the endless annular belt 64 by the drive of the turning motor 63, the turning motor 63 itself receives a reaction from the endless annular belt 64 and rotates, and is in a fixed relationship with the turning motor 63. One pivot arm 40 rotates. The endless annular belt 64 may be a circular chain. One or more gears may be interposed between the turning motor 63 and the turning shaft portion 96 instead of or in addition to the endless annular belt 64. The turning motor 63 may be directly connected to the turning shaft portion 96.

Note that the turning mechanism 62 may be provided within the upper frame 95. In this case, the pivot shaft portion 96 and the pivot arm 40 may be fixedly connected, and the pivot shaft portion 96 rotatably supported on the upper frame 95 may be rotated together with the pivot arm 40.

The center axis X1 of the pivot shaft section 96 is located between the X-ray generating section 42 on one end side of the pivot arm 40 and the X-ray detecting section 44 on the other end side of the pivot arm 40. Therefore, by the rotation mechanism 62 rotating the rotation arm 40, the X-ray generation section 42 and the X-ray detection section 44 can rotate around the central axis X1 of the rotation shaft section 96.

In this embodiment, the imaging device 22 is provided on the rotating arm 40. The imaging device 22 is provided at a position where it can image the head P held by the subject holding unit 32. The imaging device 22 is, for example, a visible light camera. Here, the imaging device 22 is supported on the upper part of the housing 46 facing the X-ray generating unit 42 so as to face the X-ray generating unit 42. The imaging range of the imaging device 22 is set to, for example, a range including the head P and shoulders S of the subject M held by the subject holding unit 32. The imaging device 22 may be omitted. A modified example using the imaging device 22 will be described later.

As shown in Figures 5 and 6, the axis movement mechanism 70 is a mechanism that moves the pivot shaft portion 96 in a direction perpendicular to the central axis of the pivot shaft portion 96, and in this embodiment, the pivot shaft movement mechanism 70 is an XY direction movement mechanism that moves the pivot shaft portion 96 in the X-axis direction and the Y-axis direction. The axis movement mechanism 70 includes, for example, an XY table 72 and drive motors 76a, 76b. The axis movement mechanism 70 is provided, for example, within the upper frame 95.

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 provided movably along the X-direction, and moves the swing arm 40 in the lateral direction (X-axis direction). The Y-direction movable table 74 is provided movably 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 movably in the Y-direction relative to the upper frame 95, and the X-direction movable table 73 is supported movably in the X-direction relative to the Y-direction movable table 74. . As the Y-direction movable table 74 moves, the X-direction movable table 73, the pivot shaft portion 96, and the pivot arm 40 move along the Y direction. Furthermore, as the X-direction movable table 73 moves, the pivot shaft portion 96 and the pivot arm 40 move along the X-direction.

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

The X-direction movable table 73 and the Y-direction movable table 74 may be driven to move by a linear motor mechanism, a rack and pinion mechanism, a mechanism using a belt and a pulley, or the like. The axis movement mechanism 70 does not need to be an XY direction movement mechanism, and may be an articulated robot arm device.

In this embodiment, the axis moving mechanism 70 moves the pivot shaft portion 96, the pivot mechanism 62, and the pivot arm 40 in the X-axis direction and the Y-axis direction. Therefore, while the rotating arm 40 is being rotated by the rotating mechanism 62, the mechanical rotating axis X1 (the central axis of the rotating shaft portion 96) of the rotating arm 40 can be moved along the XY direction. Thereby, the X-ray detection section 44 and the X-ray generation section 42 can perform a combined movement of the rotation movement by the rotation mechanism 62 and the axis movement movement by the axis movement mechanism 70. By adjusting the movement path of the rotation shaft section 96 by the axis movement mechanism 70, the rotation trajectory of the X-ray detection section 44 and the X-ray generation section 42 can be set.

Note that the pivot axis moving mechanism may be provided on the pivot arm side. In this case, the lower end of the pivot shaft portion 96 fixed at a fixed position within the XY plane of the upper frame 95 is supported by a pivot shaft moving mechanism provided on the pivot arm side. The pivot shaft moving mechanism moves the pivot shaft portion 96 in the XY directions relative to the pivot arm 40, so that the pivot arm can move in the XY directions with respect to the pivot shaft portion 96 at a fixed position. .

It is not essential that the drive mechanism 60 include the axis movement mechanism 70. For example, instead of providing the axis movement mechanism 70, the end of the swing arm 40 on the X-ray detection unit 44 side is moved along the longitudinal direction of the swing arm 40 by an expansion/contraction mechanism such as a linear motor or a rack and pinion mechanism. It may be configured to be extendable and retractable. In this case, the X-ray detection unit 44 moves in two-dimensional directions along the rotation plane of the X-ray detection unit 44 and the like by the expansion and contraction drive of the rotation arm 40, thereby changing the rotation trajectory of the X-ray detection unit 44. . Further, the X-ray detection section 44 may be configured to be movable toward and away from the X-ray generation section 42 at the end of the swing arm 40 by a movable support mechanism such as a linear motor or a rack and pinion mechanism. In this case, the movable support mechanism moves the X-ray detector 44 forward and backward relative to the X-ray detector 44, thereby changing the orbit of the X-ray detector 44.

In this embodiment, the swivel arm 40 is supported on the support column 80 so that it can be driven to move up and down. More specifically, as shown in Figs. 1 and 2, the support column 80 is provided with a vertical drive unit 82 that moves the upper frame 95 up and down along the Z-axis direction. The vertical drive unit 82 is a mechanism that drives the upper frame 95 to move up and down relative to the support column 80. The vertical drive unit 82 includes, for example, a motor 83, a ball screw 84, a nut unit 85, and multiple (here, four) roller units 86.

A base end portion of the upper frame 95 surrounds a portion of the column portion 80 in the vertical direction. A roller section 86 is provided at the base end 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 provided on the surface of the support portion 80 and extending in the Z-axis direction. Thereby, the upper frame 95 is supported so as to be movable up and down along the support column 80. At this time, the rotation of the upper frame 95 around the Z-axis relative to the support column 80 is suppressed by the roller section 86 moving along the rail. When considering that the vertical drive section 82 includes an element that guides the movement direction of the upper frame 95, it can be considered that the vertical drive section 82 includes a motor 83, a ball screw 84, a nut section 85, a roller section 86, and a rail 80r. .

A motor 83 is supported at a fixed position relative to the support column 80. In the example shown in FIG. 2, the motor 83 is located at the bottom of the support column 80. The motor 83 rotates a ball screw 84 extending in the Z-axis direction around 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 unrotatably fixed to the base end portion of the upper frame 95. Then, as the ball screw 84 rotates in accordance with the rotation of the motor 83 in the forward or reverse direction, the nut portion 85 moves upward or downward. As the nut portion 85 moves, the upper frame 95 moves up and down in the Z-axis direction. As a result, the rotating arm 40 and the X-ray generating section 42 and the X-ray detecting section 44 supported by the rotating arm 40 move up and down along the Z-axis direction.

The subject holding section 32 is a member that holds the person M (head P) to be photographed. In this embodiment, the subject holding section 32 includes a front tooth region fixing section that fixes the front tooth region Pa of the head P. More specifically, the subject holding section 32 includes a chin rest 33, a head holder 34 (see FIG. 1), and a lower frame 35.

The chin rest 33 supports the tip of the lower jaw of the head P, thereby fixing the front tooth region Pa in a fixed position. Here, the anterior tooth region Pa refers to the front teeth of the head P and a region that serves as a base for supporting the front teeth, and includes, for example, the front teeth themselves and the lower jaw (particularly the tip of the chin). That is, the chin rest is an example of a front tooth region fixing part. The front tooth area fixing part does not need to be a chin rest, and may be a bite piece that is bitten by the upper and lower front teeth, for example.

The head holder 34 positions the head P in the X-axis direction by holding the head P from both sides thereof. In the subject holding section 32, the front tooth region fixing section or the head holder 34 may be omitted.

The base end of the lower frame 35 is supported in a cantilever manner on the support 80, and the tip of the lower frame 35 extends horizontally from the support 80. The chin rest 33 and head holder 34 are supported on the tip of the lower frame 35. The chin rest 33 and 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 rotating arm 40. The head P supported by the subject holding unit 32 is held in a fixed position between the X-ray generating unit 42 and the X-ray detecting unit 44 while the X-ray generating unit 42 and the X-ray detecting unit 44 are rotating.

The subject holding unit 32 is driven to move up and down by the holding unit drive unit 36. That is, the base end of the lower frame 35 is supported on the support unit 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 drive unit 36.

The holding section driving section 36 includes a motor 36a, a ball screw 36b, a nut section 36c, and a plurality of (here, four) roller sections 36d. A base end portion of the lower frame 35 surrounds a portion of the column portion 80 in the vertical direction. A roller portion 36d is provided within the base end portion of the lower frame 35. The roller portion 36d is fixed within the lower frame 35 so as to be able to travel along a rail 80r provided on the support portion 80 and extending in the Z-axis direction. Thereby, the lower frame 35 is supported so as to be movable up and down along the support column 80. At this time, the rotation of the lower frame 35 about the Z-axis relative to the support column 80 is suppressed by the roller portion 36d moving along the rail. When considering that the holding part driving part 36 includes an element that guides the moving direction of the lower frame 35, the holding part driving part 36 includes a motor 36a, a ball screw 36b, a nut part 36c, a roller part 36d, and a rail 80r. You can think about it.

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

The nut portion 36c is supported on the base end of the upper frame 95. The nut portion 36c is fixed to the base end of the upper frame 95 so that it cannot rotate. The ball screw 36b, which reaches the base end of the upper frame 95, is screwed into the nut portion 36c.

The ball screw 36b rotates in accordance with the forward or reverse rotation of the motor 36a, and in accordance with the rotation, the lower frame 35 can move up and down with respect to the nut portion 36c into which the ball screw 36b is screwed. As the lower frame 35 moves up and down, the chin rest 33 and 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 section 32 and the vertical position of the X-ray imaging area by the X-ray generating section 42 and the X-ray detecting section 44 can be adjusted synchronously or separately. It can also be adjusted to

For example, by raising and lowering the rotating arm 40 relative to the head P while maintaining the height at which the head P is held by the subject holding unit 32 at a constant position, the X-ray irradiation location on the head P can be adjusted. can be changed in the Z-axis direction. Specifically, in accordance with the actual position of the head P, the swing arm 40 and the subject holder 32 are moved while the lower frame 35 is not raised or lowered relative to the upper frame 95 by the holder drive unit 36. It is raised and lowered by the vertical drive unit 82, and the head P is held by the chin rest 33 and head holder 34. Thereafter, the vertical drive unit 82 raises the rotating arm 40, and the holding unit drive unit 36 moves the subject holding unit 32 relative to the rotating arm 40 so as to maintain the subject holding unit 32 at a constant height position. lower to. Alternatively, the vertical drive unit 82 lowers the swing arm 40, and the holding unit drive unit 36 moves the subject holding unit 32 relative to the swing arm 40 so as to keep the subject holding unit 32 at a constant height. raise.

Further, the upper frame 95 and the lower frame 35 are connected via a ball screw 36b. Therefore, the rotating arm 40 and the subject holding section 32 are moved up and down integrally by the vertical drive section 82.

The upper frame 95 also serves as an imager supporter that supports the imager, which is the X-ray generating section 42 and the X-ray detecting section 44. The lower frame 35 also serves as a subject supporter that supports a subject holder called the subject holding section 32. The upper frame 95 and the lower frame 35 are connected by a ball screw 36b, and are an imaging supporter of an imager supporter/subject supporter connection type. The vertical drive unit 82 is also an imager elevator that raises and lowers at least the imager supporter. The holding unit driving unit 36 is also a subject elevator that raises and lowers the subject supporter. The holding unit driving 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 an imager-subject distance adjuster.

The holding part drive part 36 may not be provided, and the vertical drive part 82 may raise and lower only the imager supporter, and the subject supporter may be raised and lowered by another vertical drive part independent from the vertical drive part 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.

In any case, the X-ray imaging apparatus 20 includes an imager elevator and an imager-subject distance adjuster for elevation in the Z direction.

The imaging control section 100 controls the X-ray imaging operation of the imaging main body section 30, and is a type of computer device. In this embodiment, the imaging control unit 100 can function as a rotation control unit that controls the operation of the rotation arm 40 by the drive mechanism 60 during panoramic X-ray imaging. In addition to controlling the operation of the rotating arm 40, the photographing control section 100 may also be configured to perform various other types of control. For example, the operation of the operation display unit 110 may be controlled to control reception of operations and control of display.

Figure 7 is a block diagram showing an example of the electrical configuration of the X-ray imaging device 20. The imaging control unit 100 includes, for example, at least one processor 102 and a memory unit 104.

The storage unit 104 is composed of a non-volatile storage device such as a flash memory or a hard disk drive. The storage unit 104 stores an imaging program 104a that receives various instructions related to X-ray imaging and controls the rotation mechanism 62, the axial movement mechanism 70, the vertical drive unit 82, the holder drive unit 36, the X-ray generator 43, the X-ray beam shape adjustment unit 50, etc. in accordance with the various instructions to control the X-ray imaging operation. The storage unit 104 also stores first orbit information 104b and second orbit information 104c. The first orbit information 104b and the second orbit information 104c are information for determining the orbit of the X-ray detection unit 44 when performing panoramic X-ray imaging. The first orbit information 104b and the second orbit information 104c determine orbits different from each other.

The trajectory of movement of the X-ray detection unit 44 during X-ray imaging is defined as an X-ray detection trajectory DTL. The trajectory of the X-ray detection section 44 on the XY plane by the drive mechanism 60 is defined as a horizontal trajectory HZL, and the trajectory of the rotation of the X-ray detection section 44 on the XY plane is defined as a horizontal rotation trajectory HRL. The vertical movement trajectory of the X-ray detection unit 44 by the vertical drive unit 82 is defined as an elevation trajectory ELL. When X-ray imaging is performed with horizontal rotation of the X-ray detection unit 44 accompanied by vertical displacement, the X-ray detection trajectory DTL becomes a composite trajectory of the horizontal rotation trajectory HRL and the elevation trajectory ELL. Such a composite trajectory may be referred to as a turning elevation trajectory REL.

The X-ray detection trajectory DTL of the X-ray detection unit 44 during panoramic X-ray photography may be a rotating elevation trajectory REL. The turning elevation trajectory REL may include a case where the amount of vertical displacement of the X-ray detection unit 44 is zero. The information that determines the horizontal trajectory HZL of the X-ray detector 44 is referred to as horizontal movement information HZI, and the information that determines the horizontal orbit HRL of the X-ray detector 44 is referred to as horizontal rotation movement information HRI. The information that determines the elevation trajectory ELL of the X-ray detector 44 is referred to as elevation information ELI. The vertical displacement information 204d is an example of the vertical displacement information ELI. This elevation information ELI may include a case where the amount of displacement of the X-ray detector 44 in the vertical direction is zero.

In an apparatus configured to allow the horizontal rotation of the X-ray detection unit 44 to be accompanied by vertical displacement and to be controlled during panoramic X-ray imaging, the trajectory of the X-ray detection unit 44 may be defined as a rotational elevation trajectory REL. It is possible. The turning elevation trajectory REL can include a case where the displacement amount of the vertical movement of the X-ray detection unit 44 during panoramic X-ray imaging is zero, or a case where it is larger than zero. . If it is greater than zero, it may include displacement in the +Z direction as well as displacement in the -Z direction.

The storage unit 104 stores drive information 104DR (support unit drive information 104DR) regarding 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 photography, drive information 104DRC for X-ray CT photography, and the like. If the drive information 104DR ultimately determines the trajectory of the X-ray detector 44 in X-ray photography, the drive information 104DR is also information for determining the trajectory of the X-ray detector 44. If the drive information 104DR ultimately determines the trajectory of the X-ray generator 42 in X-ray photography, the drive information 104DR is also information for determining the trajectory of the X-ray generator 42. In the drive information 104DR, the element that determines the trajectory of the X-ray detector 44 may be considered as X-ray detection trajectory information 104DTI, and the element that determines the trajectory of the X-ray generator 42 may be considered as X-ray generation trajectory information 104GNI. If the set of the X-ray generating section 42 and the X-ray detecting section 44 is an X-ray imaging element, the drive information 104DR determines the trajectory of the X-ray generating section 42 and the X-ray detecting section 44, that is, the X-ray imaging element. It may be considered as element trajectory information 104E. It may be considered that the X-ray detection trajectory information 104DTI in the drive information 104DRP includes the first turning trajectory information 104b and the second turning trajectory information 104c.

The movement of the X-ray detection section 44 during panoramic X-ray imaging is caused by the rotation operation of the X-ray detection section 44 by the rotation mechanism 62 and the movement operation of the rotation shaft section 96 by the axis movement mechanism 70 while the rotation mechanism 62 is rotating. It becomes a combined movement. Therefore, the first turning trajectory information 104b and the second turning trajectory information 104c are, for example, the turning operation of the X-ray detection unit 44 by the turning mechanism 62, and the movement path of the turning shaft part 96 by the axis moving mechanism 70 in response to the turning operation. It may also be information that associates the The rotation operation of the X-ray detection unit 44 by the rotation mechanism 62 may be expressed, for example, as a rotation angle of the X-ray detection unit 44 based on any initial angle. The movement path of the pivot shaft 96 is determined by, for example, data that determines changes in the rotational direction and rotational speed of the X-axis drive motor 76a and the Y-axis drive motor 76b that move the pivot shaft 96, and the position of the pivot shaft 96. It may be expressed by a data string of determined XY coordinates, or a relational expression using x and y coordinates as variables. The support control unit 102a controls the rotation mechanism 62 and the axis movement mechanism 70 based on the first rotation trajectory information 104b or the second rotation trajectory information 104c, thereby moving the X-ray detection unit 44 to the first rotation trajectory or the second rotation trajectory information 104c. It can be rotated along a second rotation trajectory.

The processor 102 includes a CPU (Central Processing Unit) and the like. Various functions of the processor 102 are realized by the processor 102 executing the photographing program 104a. The processor 102 is configured by a circuit, and includes functional blocks realized by executing the imaging program 104a, such as a support control section 102a, a trajectory setting section 102b, an X-ray detection section drive control section 102e, a detection signal processing section 102f, It includes a holding section control section 102c and an irradiation control section 102d. That is, the processor 102 is constituted by a circuit that executes the imaging program 104a and performs, for example, support control, trajectory setting, drive control of the X-ray detection section, detection signal processing, holding section control, and irradiation control.

The support control unit 102a controls the X-ray generation unit 42 and the X-ray detection unit 44 to hold the head P of the person to be photographed M held by the subject holding unit 32 between them. The rotating operation of the rotating arm 40 by the rotating mechanism 62 and the axis moving mechanism 70 is controlled so that the rotating arm 40 rotates around P to perform panoramic photography.

The support control unit 102a may control the movement of the vertical drive unit 82 to control the elevation of the swing arm 40.

The orbit setting unit 102b is configured to be able to set a first orbit R1 and a second orbit R2 as panoramic orbits of the X-ray detection unit 44 for the same person to be imaged. Then, either one of the first orbit R1 and the second orbit R2 is selectively set as the actual orbit during panoramic X-ray imaging.

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.

The detection signal processing unit 102f generates X-ray imaging data suitable for generating a panoramic X-ray image, etc., based on the electrical signal from the X-ray detector 45. The X-ray imaging data is provided to an image processing device 180.

The holding section control section 102c may control the height position of the subject holding section 32 by controlling the holding section driving section 36.

The irradiation control section 102d controls the X-ray generator 43 and the X-ray beam shape adjustment section 50. For example, when performing X-ray panoramic imaging, the X-ray beam shape adjustment unit 50 is controlled to form the X-ray beam into an X-ray slit beam. Further, when performing launch irradiation during X-ray panoramic imaging, the X-ray beam shape adjustment unit 50 is controlled according to the launch angle. The vertical position of the X-ray detector 44 may also be adjusted by the X-ray detector vertical movement drive unit 47 according to this launch angle. Furthermore, the irradiation control unit 102d can control whether or not X-rays are emitted and the intensity of the X-rays by controlling at least one of the voltage and current supplied to the X-ray tube of the X-ray generator 43. .

Here, we will mainly explain the operation when the imaging control unit 100 performs panoramic X-ray imaging, but the imaging control unit 100 also controls the X-ray imaging apparatus 20 when performing other X-ray CT imaging and cephalometric imaging. It also controls various parts of the X-ray detector 45 and executes various processes based on electrical signals from the X-ray detector 45.

The photographing control section 100 is connected to an operation display section 110. The operation display section 110 includes a display device for displaying various information and an information input device for inputting various information (including photographing conditions, etc.) and commands to the photographing control section 100. The display device is realized by a liquid crystal display device, an organic EL (Electroluminescent) display device, or the like. The information input device may be realized by a switch, a pointer, a touch detection device of a touch panel, or the like. The operation display unit 110 may be configured, for example, by a touch panel display device in which a touch detection device is incorporated into 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 units. The operation display section 110 may be provided at any part of the X-ray imaging apparatus 20 (for example, the support section 80, the housing 46, etc.), or at a different location from the X-ray imaging apparatus 20 (for example, at a It may be provided on the outer wall of the X-ray room or on another table. The operation display section 110 can function as a shooting setting reception section 110a.

The photographing control unit 100 is connected to an image processing device 180 via a communication interface 108. Image processing device 180 is a type of computer device. The image processing device 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 device 180 includes, for example, a control section 182, a storage section 183, an image processing section 184, an operation section 185, a display section 186, and the like. The storage unit 183 is a nonvolatile storage device such as a flash memory or an HDD, and stores control programs, X-ray imaging data, X-ray image data, and the like. The control unit 182 includes at least one processor, and the control unit 182 operates according to a control program stored in the storage unit 183 to generate an X-ray image based on the X-ray imaging data transmitted from the imaging control unit 100. A process for generating data (particularly X-ray panoramic imaging data) is executed. For example, when panoramic imaging is performed with the X-ray imaging apparatus 20, the imaging control unit 100 performs arithmetic processing to obtain a panoramic image of a target tomogram. Specifically, the imaging control unit 100 performs a shift operation that adds pixel values to a plurality of rectangular X-ray projection images acquired in the imaging main body unit 30 by shifting them relative to each other according to their positions on the tomogram. By performing the addition process, one panoramic X-ray image is obtained.

FIG. 7 shows an image processing section 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 an image processing processor, or may be realized by cooperation of these processors. You can. The generated X-ray image data may be stored in the storage unit 183 or in another storage device, such as the storage device of the imaging control unit 100 or the storage device of the server.

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

The display section 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 main display section 186 (see FIG. 1).

Note that some or all of the functions implemented in each of the above units may be implemented in hardware using a dedicated logic circuit or the like. Further, 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.

<Operation of X-ray imaging device>
The operation of the X-ray imaging apparatus will be explained with a focus on panoramic X-ray imaging. Note that 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 processing related to panoramic X-ray photography.

When the X-ray imaging device 20 is started, power is supplied to each unit, and the imaging main body unit 30, imaging control unit 100, and image processing device 180 are in a standby state. Then, an imaging mode setting screen is displayed on the operation display unit 110. The imaging mode setting screen is a screen for selecting one mode from, for example, panoramic X-ray imaging mode, X-ray CT imaging mode, etc. When the panoramic X-ray imaging mode is selected through a touch operation on the operation display unit 110, etc., panoramic imaging mode processing is started.

Note that when performing panoramic X-ray photography, the heights of the rotating arm 40 and the subject holding section 32 are adjusted in accordance with the height position of the head P of the person M to be photographed. The height adjustment may be performed by the operator inputting an instruction to raise or lower the rotating arm 40 and the subject holding part 32 through the operation display unit 110 or the like.

When the panoramic imaging mode process is started, in step S1, the first rotation orbit R1 is set as the initial orbit or default orbit based on the first rotation orbit information 104b. The first rotation orbit R1 may be a general-purpose rotation orbit that has been used in panoramic X-ray imaging devices in the past. Therefore, if there is no special instruction regarding the rotation orbit, panoramic X-ray imaging is performed by rotating the X-ray detection unit 44 along the first rotation orbit.

In the next step S2, it is confirmed whether the setting has been changed to the second orbit R2. The setting change to the second orbit R2 is performed, for example, through the operation display section 110. For example, an icon for changing the setting to the second orbit R2 is displayed on the operation display unit 110, and by touching the icon, changing the setting to the second orbit R2 is accepted. If it is determined that there is a setting change to the second orbit R2, the process proceeds to step S3, and if it is determined that there is no setting change, step S3 is skipped and the process proceeds to step S4.

In step S3, a second orbit is set as the orbit based on the second orbit information 104c.

In the next step S4, it is determined whether or not a request to start shooting has been received. The request to start shooting may be received, for example, through a push button switch (called a deadman's switch) connected to the shooting control unit 100. If it is determined that a request to start shooting has not been received, the process returns to step S2, and the processes of steps S2 and S3 are repeated. If it is determined that a request to start shooting has been received, the process proceeds to step S5.

In step S5, panoramic X-ray photography is performed while the X-ray detection unit 44 is rotated according to the set orbit. That is, according to the set first orbit information 104b or second orbit information 104c, the rotation mechanism 62 and the axis movement mechanism 70 are controlled to move the X-ray detection unit 44 to the first orbit R1 or the second orbit R1. Turn along R2. In panoramic X-ray imaging, the entire rotating arm 40 pivots, so the X-ray generating section 42 also pivots. While turning, X-rays emitted from the X-ray generator 42 pass through the head P and enter the X-ray detector 44 . X-ray imaging data is generated based on electrical signals corresponding to the X-rays 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.

Note that when performing panoramic X-ray imaging, the range of the panoramic imaging area, etc. may be set through the operation display unit 110 or the like, and the X-ray beam shape adjustment unit 50 may be controlled in accordance with the settings.

In addition, when performing panoramic X-ray photography, the launch angle of the X-ray beam is set via the operation display unit 110, etc., and the X-ray beam shape adjustment unit 50 is controlled in accordance with this setting to adjust the irradiation direction of the X-ray beam, and the X-ray detector vertical movement drive unit 47 is controlled in accordance with the irradiation direction to adjust the vertical position of the X-ray detection unit 44.

An example of the first rotation trajectory R1 and the second rotation trajectory R2 will be described. Figure 9 shows an example of the first rotation trajectory R1, and Figure 10 shows an example of the second rotation trajectory R2. In Figures 9 and 10, the shape of the head P and the shape of the shoulders S are shown. The shapes of the head P and shoulders S are standard.

The first orbit R1 and the second orbit R2 are arcuate lines along the outer circumferential side of the dental arch Arc. The first rotation trajectory R1 and the second rotation trajectory R2 may be set in a range in which X-rays transmitted through a region including the front teeth and molar teeth in the dental arch, as well as the temporomandibular joint and the vicinity of the mandibular angle can be detected. From this point of view, the first turning trajectory R1 and the second turning trajectory R2 are arcuate trajectories in a range of more than 90° (for example, a range of ±115°) in the left and right directions centered on the central front part of the head P in the left-right direction. It may be. The first turning trajectory R1 may be set to the horizontal turning trajectory HRL. The first turning trajectory R1 may be set to a turning elevation trajectory REL in which the amount of vertical displacement of the X-ray detection unit 44 during panoramic X-ray imaging is zero.

The second turning trajectory R2 is longer than the first turning trajectory R1 in the front of the head P (at least in front of the center of the head P in the left-right direction) and on the sides (at least on the left and right of the center of the head P in the front-back direction). The orbit is set close to the surface. Therefore, the X-ray detection unit 44 rotating on the second orbit R2 can detect X-rays closer to the dental arch Arc, which is the region of interest.

The center of the head P is defined as a head center HC, and the point on the head surface through which the X-ray slit beam passes is defined as a point IP. There are various ways to determine the head center HC, such as the intersection of the front-rear center and the left-right center. The direction in which X-rays advance at point IP as viewed in the Z direction and the direction parallel to this direction will be referred to as the forward irradiation direction, and the direction opposite to the forward irradiation direction will be referred to as the reverse irradiation direction. Since the distance between the head center HC and the point IP changes depending on the position of the point IP due to a change in the irradiation direction, the X-ray detection section 44 and the rotation axis section 96 must be moved to accommodate this change. It becomes necessary. This amount of movement is considered to be an offset value, and the relationship between movement according to the distance between the X-ray detection unit 44 and the surface of the head P and movement of the pivot shaft portion 96 is considered. As shown in FIGS. 9 and 10, in order to move the X-ray detector 44 along the first orbit R1 or the second orbit R2, for example, the X-ray detector 44 pivots around the pivot shaft 96. In this case, the pivot shaft portion 96 may be moved by the shaft moving mechanism 70. For example, the position of the pivot shaft portion 96 with respect to the center of the head P may be adjusted according to the distance of the first orbit R1 or the second orbit R2 with respect to the surface of the head P. For example, in the portion of the orbits R1 and R2 that approaches the surface of the head P (the front of the head P), the movement closer to the surface is realized by moving the rotation shaft portion 96 in the reverse illumination direction, and the rotation trajectory R1, In the portion of R2 that moves away from the surface of the head P (on the side of the head P), movement away from the surface is realized by moving the pivot shaft portion 96 in the forward irradiation direction.

In the configuration example shown in FIGS. 9 and 10, the movement trajectory Q2 of the rotation shaft portion 96 corresponding to the second rotation trajectory R2 is longer than the movement trajectory Q1 of the rotation shaft portion 96 corresponding to the first rotation trajectory R1. It is set at a position advanced in the reverse illumination direction on the rear and side sides of P. As a result, the X-ray detection section 44 moving along the second rotation trajectory R2 is positioned in front of and on the side of the head P, more than the X-ray detection section 44 moving along the first rotation trajectory R1. approach the surface.

The first rotation trajectory R1 may be a trajectory that is adapted to the shape of a standard head P. In other words, the first rotation trajectory R1 may be set to a path that allows the X-ray detection unit 44 to rotate around the standard head P without coming into contact with the head P, taking into consideration the shape and size of the X-ray detection unit 44 relative to the shape of the standard head P.

Here, the standard shape of the head P means the average shape of the head in the country or region where this X-ray imaging apparatus 20 is used, regardless of whether it is an adult, child, gender, etc. You can. The standard shape of the head P may refer to an average head in the country or region where the present X-ray imaging apparatus 20 is used, targeting adults in the country or region. A standard head P means that the shape and size of the dental arch Arc within the head P is also standard, and therefore the first orbit R1 revolves around a range in which such a dental arch Arc can exist. It may be set as such. Of course, a plurality of groups may be distinguished, for example, adults and children, and the head shape may be adapted to the average head shape of each group.

The second orbit R2 may have a similar shape and a smaller shape than the first orbit R1. In addition, the degree of contraction of the left-right width (X-direction width) of the second turning path R2 with respect to the left-right width (X-direction width) of the first turning path R1 is determined by the longitudinal length (Y-direction length) of the first turning path R1. The degree of contraction in the longitudinal length (Y-direction length) of the second turning trajectory R2 is greater than the degree of contraction in the longitudinal length (Y-direction length) of the second turning trajectory R2. The shape may be more contracted in the (X direction).

The second turning trajectory R2 is also a trajectory that is closer to the chin rest 33 than the first turning trajectory R1 in front of the chin rest 33, which is an example of the front tooth region fixing part. Further, the second turning trajectory R2 is also a trajectory closer to the chin rest 33 than the first turning trajectory R1 in the left-right direction of the photographic subject M held by the subject holding section 32, that is, in the X direction.

In relation to the shape of the head P, the second turning trajectory R2 is within 10 cm from the surface of the head P in front of the head P (at least in front of the center of the head P in the left-right direction (X direction)). It may be a trajectory passing through a position.

The second turning trajectory R2 may be a trajectory in which a partial trajectory in the front range of the anterior tooth region Pa is closer to the surface of the head P than a partial trajectory in other ranges. In other words, the second turning trajectory R2 may be a trajectory in which a region at the center of the head P in the left-right direction (X direction) approaches the surface of the head P the closest to other regions. .

In these cases, in front of the head P, there is no shoulder S with which the X-ray detection unit 44 easily comes into contact, so the X-ray detection unit 44 can easily contact the head P without contacting the person M to be imaged. Can be approached.

Furthermore, the second turning trajectory R2 may be a trajectory that passes through a position within 10 cm from the surface of the head P over the entire circumference of the head P. In this case, it is preferable to check whether the X-ray detection unit 44 contacts the shoulder S according to the shape of the shoulder S of the person M to be photographed. If there is a possibility that the X-ray detector 44 will come into contact with the shoulder S, either stop the setting of the second turning trajectory R2 or move the X-ray detector 44 up and down while turning along the second turning trajectory R2. One possibility is to adjust the position. A modification example in this case will be explained later.

At least one of the first turning trajectory R1 and the second turning trajectory R2 is longer than the distance to the surface of the head P at the side of the head P than the distance to the surface of the head P at the front of the head P. may be a large orbit. In other words, at least one of the first orbit R1 and the second orbit R2 is in the front-rear direction ( The distance to the side surface of the head P at the center (Y direction) is the head at the center of the head P in the left-right direction (X direction) at the part where the X-ray detection unit 44 faces the front part of the head P during the orbit. The trajectory may be farther than the distance of the portion P to the front surface.

When the arrangement of the X-ray detection unit 44 is such that 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 comparing arrangements AA and BA, the state of arrangement AA is expressed as "high proximity" and the state of arrangement BA is expressed as "low proximity."

The distance between the X-ray detector 44 and the surface of the head P (point IP) when the X-ray detector 44 is in front of the head P is defined as the distance FD, and the X-ray detector 44 is located in front of the head P. The distance between the X-ray detection unit 44 and the surface of the head P (point IP) when it is on the side is defined as the distance SD. Let the value of distance FD/distance SD be the proximity/separation ratio FSR. A smaller proximity-separation ratio FSR is expressed as "high front approach ratio" and "low lateral approach ratio", and a larger proximity-separation ratio FSR is expressed as "low front approach ratio", It shall be expressed as "high lateral approach ratio". Compared to a turning trajectory in which the distance FD and the distance SD are equidistant, the turning trajectory R of this embodiment has a high forward approach ratio.

The distance in front of the head P (at least in front of the center of the head P in the left-right direction) to the front surface of the head P may be expressed as the separation distance of the trajectory with respect to the center of the front part of the head in the left-right direction. The above-mentioned distance to the side surface of the head P on the sides of the head P (at least left and right in the center of the head P in the front-back direction) is expressed as the distance between the orbits and the center of the side of the head in the front-back direction. You can.

Here, a portion, such as a nose or an ear, or both, that protrudes from the roundness of the head when viewed in the -Z direction is referred to as a head protrusion. When considering the distance between the head and the X-ray detection unit 44, it may be considered as the distance between the surface including the head protrusion, but it is assumed that there is no head protrusion and the head It can also be considered as the distance between the roundness of Only some of the multiple head protrusions may be considered missing, such as only the nose being considered missing.

While it is difficult to observe the protrusion of the torso in the front and lower part of the head P, the shoulders S can be observed in the lateral and lower parts of the head P. Therefore, when the X-ray detector 44 passes by the side of the head P, the X-ray detector 44 housing the X-ray detector 45 may come into contact with the shoulder S. Generally, the upper surface of the shoulder S has a shape that extends downward as the distance from the surface of the head P increases. Therefore, by making the X-ray detector 44 pass through a position away from the surface of the head P on the side of the head P, the X-ray detector 44 is less likely to come into contact with the shoulder S.

FIGS. 11 and 12 are explanatory diagrams showing the positional relationship of the X-ray detection unit 44 with respect to the person M to be imaged during panoramic imaging. In each of FIGS. 11 and 12, the positional relationship of the X-ray detection unit 44 with respect to the subject M viewed from the side is shown on the left, and the positional relationship of the X-ray detection unit 44 with respect to the subject M viewed from the front is shown on the right. is shown. 11 and 12, the X-ray beam is launched and irradiated, and the lower end of the housing 41 housing the X-ray generator 43 and the lower end of the housing 46 housing the X-ray detector 45 are at the same height position. An example is shown below. It is not essential that the X-ray beam be launched and irradiated, therefore, the lower end of the casing 41 housing the X-ray generator 43 is lower than the lower end of the housing 46 housing the X-ray detector 45. It may be located.

The positional relationship when the X-ray detection unit 44 rotates along the first rotation orbit R1 is shown in FIG. 11. When the X-ray detection unit 44 passes in front of the head P, there is no other body part in front of and below the head P that can come into contact with, so the X-ray detection unit 44 can move without coming into contact with the subject M. Even when the X-ray detection unit 44 passes to the side of the head P, it passes through a location that is further to the side from the surface of the head P than when the X-ray detection unit 44 moves along the second rotation orbit R2. Normally, the upper surface of the shoulder S has a shape that points downward as it moves away from the head P. Therefore, since the X-ray detection unit 44 is further to the side from the head P, the upper surface of the shoulder S is also located downward, making it less likely to come into contact with the shoulder S.

FIG. 12 shows the positional relationship when the X-ray detector 44 rotates along the second orbit R2. When the X-ray detector 44 passes in front of the head P, there are no other human body parts that come into contact with the front lower part of the head P. Can move without coming into contact with M. Even if the passing position of the X-ray detection unit 44 is closer to the surface of the head P than in the case shown in FIG. 11, it is similarly difficult to come into contact with the person M to be photographed.

When the X-ray detector 44 passes to the side of the head P, the X-ray detector 44 passes a position closer to the surface of the head P than when moving along the first orbit R1. Usually, the upper surface of the shoulder S has a shape that faces upward as it approaches the head P. Therefore, the closer the X-ray detector 44 is to the head P, the more likely the X-ray detector 44 comes into contact with the shoulder S. In the illustrated example, the X-ray detection unit 44 is in a state where it can pass above the upper surface of the shoulder S, but it has come to pass closer to the upper surface of the shoulder S than in the case of the first orbit R1. There is.

Here, there are individual differences in the positional relationship between the dental arch Arc, which is the subject of panoramic X-ray photography, and the shoulder S in the head P. For example, if the subject M has angry shoulders and a short neck, the difference in the vertical position of the surface of the shoulder S with respect to the height position of the dental arch Arc is small, so the , it is considered that the shoulder S is likely to come into contact with the shoulder S. Further, for example, if the person M to be imaged has a body shape with slender shoulders and a long neck, the difference in the vertical position of the surface of the shoulder S with respect to the height position of the dental arch Arc is larger than in the above case. Therefore, it is considered that the X-ray detection unit 44 is unlikely to come into contact with the shoulder S.

Therefore, it is thought that panoramic X-ray imaging using the first orbit R1 can be carried out on subjects M of most physiques, whereas panoramic X-ray imaging using the second orbit R2 is Depending on your physique, there may be cases where it is possible and cases where it is difficult to carry out.

When the user sets the second rotation trajectory R2 by observing the physique of the person M to be imaged or by actually turning the X-ray detection unit 44 on a trial basis, the user determines that the X-ray detection unit 44 Determine whether or not to contact person M. If the second orbit R2 is applicable, the second orbit R2 can be set (see steps S2 and S3), and panoramic X-ray photography can be performed using the second orbit R2.

According to the X-ray imaging apparatus 20 configured in this manner, the imaging control unit 100 sets the first orbit R1 and the second orbit R2 as the panoramic orbit of the X-ray detector 44 for the same person M to be imaged. It is configured so that it can be set. This second turning trajectory R2 is a trajectory that is closer to the surface of the head P than the first turning trajectory R1 in front and on the sides of the head P. Therefore, by rotating the X-ray detector 44 along the second orbit R2, the X-ray detector 44 can be moved near the surface of the head P, that is, near the dental arch Arc. . Thereby, the image of the X-rays transmitted through the dental arch Arc is clearly reflected on the detection surface of the X-ray detector 45, and the resolution of the panoramic X-ray image can be improved. Furthermore, if there is a possibility that the X-ray detector 44 will come into contact with the shoulder S of the person M to be imaged on the second orbit R2, the X-ray detector 44 should be rotated along the first orbit R1. Thus, panoramic X-ray photography can be performed while avoiding contact of the X-ray detection unit 44 with the person M to be photographed.

Further, the subject holding unit 32 includes a chin rest 33 as a front teeth region fixing unit, and the imaging control unit 100 selects a trajectory closer to the chin rest 33 than the first rotation trajectory R1 in front of the chin rest 33 as the second rotation trajectory R2. Once set, it is possible to take a panoramic image of the anterior tooth region Pa accurately positioned by the chin rest 33.

Further, if a configuration including a turning mechanism 62 and an axis moving mechanism 70 is adopted as the drive mechanism 60, when the turning arm 40 is turned by the turning mechanism 62, the axis moving mechanism 70 moves the turning shaft part 96 along the trajectory. By changing , the orbit of the X-ray detector 44 can be switched between the first orbit R1 and the second orbit R2.

If a trajectory adapted to the standard head P is set as the first orbit R1, panoramic X-ray photography can normally be performed using the first orbit R1. Then, panoramic X-ray imaging using the second orbit R2 is performed depending on the need to further improve the resolution, or when it is confirmed that the X-ray detection unit 44 does not come into contact with the head P or shoulder S. It can be carried out.

Furthermore, if the second rotation orbit R2 is set to pass through a position in front of the head P and within 10 cm from the surface of the head P, the resolution of the panoramic X-ray image, particularly the resolution in the anterior tooth region Pa, can be improved.

Moreover, if a trajectory passing through positions within 10 cm from the surface of the head P is set as the second orbit R2, the overall resolution of the panoramic X-ray image can be improved.

Further, as the second orbit R2, if the partial trajectory in the front range of the anterior tooth region Pa is a trajectory closer to the surface of the head P than the partial trajectory in other regions, the X-ray detection unit 44 is moved to the anterior tooth region Pa. The resolution of the panoramic X-ray image representing the anterior tooth region can be further improved.

Further, if a trajectory is set as the second turning trajectory R2, 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 on the front side of the head P, The X-ray detection section 44 can easily turn while avoiding contact with the shoulder S. Similarly, as the first turning trajectory R1, a trajectory is set in which the distance to the surface of the head P at the side of the head P is larger than the distance to the surface of the head P at the front of the head P. For example, the X-ray detection section 44 can easily turn while avoiding contact with the shoulder S.

<Modification>
A modified example of the first embodiment will be described. In the above embodiment, the example in which the second rotation orbit information 104c defining the second rotation orbit R2 is set and stored in advance in the storage unit 104 has been described. The imaging control unit 100 may set the second rotation orbit R2 for each individual subject M according to the physique data of the individual subject M.

Figure 13 is a flowchart showing an example of processing by the imaging control unit 100 in this modified example.

Step S11 is similar to step S1 above. In step S12 after step S11, it is determined whether or not the setting of the second turning trajectory R2 has been changed. When a setting change instruction to the second turning trajectory R2 is input in response to a touch operation on the operation display unit 110, etc., it is determined that the setting of the second turning trajectory R2 has to be changed, and the process proceeds to step S13, where a setting change instruction is input. If there is no input, the process advances to step S15.

In steps S13 and S14, the imaging device 22 is used as a head surface shape detection section that detects the surface shape of the head P, and a second turning trajectory R2 is set according to the detection result of the imaging device 22. .

That is, in step S13, the imaging device 22 images the head P and shoulders S held by the subject holding section 32. For example, the detection result may be image data obtained by rotating the X-ray detection unit 44 along the first rotation trajectory R1 that makes it difficult to contact the person M to be photographed, and capturing images of the head P from a plurality of directions. The photographic data may include the shoulder S. Since this image data includes the surface shape of the head P, this image data is an example of physique data including the physique of the head P of the person M to be photographed.

In the next step S14, a second turning trajectory R2 is set based on the surface shape of the head P.

A more specific example of steps S13 and S14 will be explained. First, the positional relationship of the imaging device 22 with respect to the rotating arm 40 and the X-ray detection unit 44 can be known information. Therefore, as shown in FIG. 14, head surface shape data representing the surface shape of the head P relative to the X-ray detection unit 44 can be generated based on the image data of the head P captured. The image data obtained by capturing images of the head P may be image data obtained by capturing images of the head P from a plurality of directions. For example, the image data may be a combination of image data of the head P taken from the front or from the back and image data of the head P taken from the left side or the right side. The horizontal section of the head P represented by the head surface shape data may be a horizontal section passing through the widest part of the horizontal section of the head P, for example, the top of the nose. In this head surface shape data, a second orbit R2 in which the X-ray detection unit 44 is unlikely to come into contact with the head P can be set. For example, a passing point passing a predetermined distance of 10 cm or less from the front of the surface of the head P may be set, and a curve passing through the passing point may be set as the second turning trajectory R2. Further, for example, a plurality of passing points passing through a predetermined distance of 10 cm or less from the surface of the head P are set at a plurality of locations around the dental arch Arc in the head P, and a curve passing through the plurality of passing points is set as a curve. It may also be set as a two-turn orbit R2. Further, for example, a plurality of candidate trajectories for the second turning trajectory R2 are set in advance and stored in the storage unit 104, and based on the head surface shape data, the X-ray detection unit 44 selects one of the plurality of candidate trajectories for the head A trajectory that can pass closest to the surface of the head P without contacting it may be set as the second orbit R2. Further, for example, an initial candidate trajectory for the second turning trajectory R2 is set in advance and stored in the storage unit 104, and the initial candidate trajectory is sequentially increased or decreased (for example, by a predetermined distance from the initial candidate trajectory). (For example, by sequentially setting a trajectory that passes through a position close to or far from the head P by 1 cm), based on the head surface shape data, the X-ray detection unit 44 is A trajectory that can pass closest to the surface of the head P may be specified, and that trajectory may be set as the second turning trajectory R2.

The setting of the second orbit R2 according to the individual person M to be imaged may be based on X-ray image data obtained by photographing the person M to be imaged in advance, for example, cephalometric imaging data. The front cephalometric data shows the left and right parts of the head P, and the side cephalometric data shows the front part of the head P. Therefore, based on the cephalometric data, the left and right parts of the head P and the front The position of the part can be determined and the second turning trajectory R2 can be set in the same manner as above. Cephalometric imaging data is also an example of physique data. Since the surface shape of the head P is also reflected in the cephalometric imaging data, the X-ray detector 45 that captures the cephalometric imaging data can be used as an example of the head surface shape detection section.

In both visible light images and X-ray images, the surface or boundary of the head P can be automatically extracted by performing image recognition processing such as edge extraction image processing. However, the surface or boundary of the head P may be specified by the user using a pointer or the like.

The device that detects the surface shape of the head P as the head surface shape 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 reference region in the X-ray imaging device 20 are reflected, and performs image processing etc. based on the captured image, so that the head P in the X-ray imaging device 20 is surface position can be recognized. Thereby, the second turning trajectory R2, etc. can be set for each individual, similarly to the above.

Further, for example, a visible light sensor or a laser sensor that detects the surface of the head P, particularly the front part and the side part, is incorporated in the swing arm 40, and the surface of the head P is detected based on the output of the sensor. Locations, in particular anterior and lateral locations, may be detected. Data including those detection results is an example of physique data. Based on these detection results, the surface position of the head P with respect to the rotating arm 40 and the X-ray detection unit 44, especially the front part and the side part, is specified, so that the second turning trajectory R2 is determined in the same way as above. Can be set.

The second turning trajectory R2 may be set individually according to the user's settings. For example, a plurality of candidate trajectories for the second turning trajectory R2 are set in advance and stored in the storage unit 104, and the user inputs the distinction between adult size and child size, or the distinction between S size, M size, and L size. By doing so, a candidate trajectory according to the input size may be set as the second turning trajectory R2.

In addition, if the shoulder S of the subject M is higher than the standard position, the second rotation trajectory R2 may be set to make a longer circuitous path to the side of the head P. In this case, as will be described later, a movement to raise the X-ray detection unit 44 to the side of the head P may be added.

If it is determined in step S12 that the setting of the second rotation trajectory R2 has not been changed, or after the second rotation trajectory R2 has been set in step S14, the process proceeds to step S15. In step S15, similar to step S4, it is determined whether or not a request to start shooting has been received. If it is determined that a request to start shooting has not been received, the process returns to step S12, and if it is determined that a request to start shooting has been received, the process proceeds to step S16.

In step S16, similarly to step S5, panoramic X-ray imaging is performed while the X-ray detection unit 44 is rotated according to the set orbit. Thereby, panoramic X-ray photography can be performed by rotating the X-ray detection unit 44 based on the second rotation trajectory R2 set according to the individual physique of the person M to be imaged.

According to this modification, the imaging control unit 100 can set the second turning trajectory R2 for each individual person M to be imaged, according to the individual physique data. Therefore, depending on the physique of the individual, panoramic X-ray photography can be performed with the X-ray detection unit 44 brought as close to the head P as possible to obtain a high-resolution panoramic X-ray image.

In this case, the second turning trajectory R2 can be easily set by setting the second turning trajectory R2 based on the detection result of the head surface shape detection unit such as the imaging device 22. Further, based on the detection result, the second turning trajectory R2 that passes directly near the surface of the head P can be easily set.

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

In this modification, an example has been explained in which the second turning trajectory R2 is set for each individual, but the same applies to the first turning trajectory R1 that turns at a position farther from the head P than the first turning trajectory R1. It may be set individually.

In the flowchart of FIG. 13, it is determined in step S12 whether or not the setting of the second turning trajectory R2 is changed, the surface shape of the head P is detected in step S13, and the second turning trajectory R2 is set in step S14. The process may be fully automatic. That is, step S12 is omitted, and first, in step S13, the surface shape of the head is detected, and the imaging control unit 100 automatically determines whether or not it is possible to perform imaging according to the second orbit R2, and if possible, perform the second orbit R2. The orbit R2 may be set, and if it is not possible, the setting of the first turning orbit R1 may be maintained. In this case, if the answer in step 15 is NO, the process may loop back to immediately before step 15.

{Second embodiment}
An X-ray imaging apparatus 200 according to a second embodiment will be described. In the description of this embodiment, the same components as those described in the first embodiment are given the same reference numerals, and the description thereof will be omitted. FIG. 15 is a block diagram showing an example of the electrical configuration of the X-ray imaging apparatus 200.

In the second embodiment, an example will be described in which the X-ray detection unit 44 is vertically displaced during panoramic X-ray imaging. That is, depending on the physique of the person M to be imaged, even if the X-ray detection unit 44 does not contact the head P, it may come into contact with the shoulder S. Even in such a case, there may be a case where it is desired to bring the X-ray detection unit 44 close to the dental arch Arc to perform panoramic X-ray photography and obtain a panoramic X-ray image with higher resolution. Even in such a case, the X-ray detection unit 44 is vertically displaced during panoramic X-ray imaging. In particular, the X-ray detector 44 is displaced upward at a portion where the X-ray detector 44 passes over the shoulder S on the side of the head P. This prevents the X-ray detector 44 from contacting the shoulder S, and allows the X-ray detector 44 to rotate on the second orbit R2 close to the head P. The second orbit R2 in this case is an example of the orbit REL in which the displacement amount of the vertical movement of the X-ray detection unit 44 during panoramic X-ray imaging is greater than zero.

In this X-ray imaging apparatus 200, the imaging program 204a stored in the storage unit 104, in addition to the processing functions of the imaging program 104a, sets the vertical displacement pattern of the X-ray detection unit 44 during panoramic X-ray imaging, It has a function of controlling the vertical drive unit 82 and the like to vertically displace the X-ray detection unit 44 based on the vertical displacement pattern during panoramic X-ray imaging. The storage unit 104 also stores vertical displacement information 204d for setting the displacement operation of the X-ray detection unit 44 during panoramic X-ray imaging. The processor 102 includes a vertical displacement setting section 102g that sets a vertical displacement pattern based on the vertical displacement information 204d, in addition to the functions in the first embodiment, by executing processing according to the imaging program 204a.

FIG. 16 is a flowchart showing a processing example of the imaging control unit 202 of the X-ray imaging apparatus 200.

When the panoramic photography mode process is started, in step S21, the first orbit R1 is set as the initial orbit based on the first orbit information 104b. Therefore, if there is no special instruction regarding the orbit, panoramic X-ray imaging is performed by rotating the X-ray detection unit 44 along the first orbit. Further, no vertical displacement is set as the initial operation. Therefore, if there is no special instruction to change the amount of vertical displacement, the X-ray detection unit 44 performs panoramic X-ray imaging without vertical displacement.

In the next step S22, similar to step S2 above, it is confirmed whether or not the setting has been changed to the second orbit R2. If it is determined that the setting has been changed to the second orbit R2, the process proceeds to step S23, and if it is determined that the setting has not been changed, step S23 is skipped and the process proceeds to step S24.

In step S23, the same processing as in step S3 above is performed.

In step S24, it is determined whether the vertical displacement amount is set. The vertical displacement amount is set, for example, through the operation display section 110. For example, an icon for changing the setting of the vertical displacement amount is displayed on the operation display unit 110, and if it is determined that the setting of the vertical displacement amount has been changed by touching the icon, the process proceeds to step S25, and the setting is not changed. If it is determined, step S25 is skipped and the process proceeds to step S26.

In step S25, a vertical displacement pattern is set based on the set vertical displacement amount.

Here, an example of the vertical displacement information 204d will be explained. For example, as shown in FIG. 17, the vertical displacement information 204d includes a vertical displacement pattern 204d1 in which height information of the X-ray detector 44 is associated with a turning angle of the X-ray detector 44 during panoramic X-ray imaging. The vertical displacement pattern 204d1 data may be expressed by a data string or by an expression using the turning angle as a variable. If the initial position of the turning angle is the front position of the center of the head P in the left-right direction (X direction), and if the clockwise direction from the initial position is the + direction and the counterclockwise direction is the - direction, then the height is the highest at the turning angle of 0°. The height is set to be the highest at a turning angle of ±90°. At a turning angle (for example, ±90°) in which the X-ray detector 44 is located to the side of the head P, the height hm [mm] of the X-ray detector 44 exceeds the height hs [mm] of the shoulder S. is set to Between the turning angle of 0° and the turning angle of ±90°, the height is set so as to change smoothly while drawing a curve. In a range where the turning angle exceeds ±90°, the height at the turning angle ±90° may be maintained, or the height may be changed to become smaller. The imaging control unit 202 preferably adjusts the height position of the X-ray detection unit 44 by setting the initially positioned height position of the X-ray detection unit 44 to the height at a rotation angle of 0°.

The imaging control unit 100 controls the driving of the vertical drive unit 82 to add vertical movement to the X-ray detection unit 44 along the vertical displacement pattern 204d1. The vertical drive unit 82 functions as a mechanism for moving the swing arm 40 up and down with respect to the head P.

The vertical displacement information 204d may include only one vertical displacement pattern 204d1. In this case, in step S24, a setting as to whether or not to perform vertical displacement is input, and in step S25, the one vertical displacement pattern 204d1 is set as the vertical displacement pattern.

The vertical displacement information 204d may include a plurality of vertical displacement patterns 204d1, 204d2, and 204d3. The plurality of vertical displacement patterns 204d1, 204d2, and 204d3 have different heights. The vertical displacement patterns 204d1, 204d2, and 204d3 may be considered as examples of vertical movement information regarding the movement of the X-ray detection unit 44 in the vertical direction. In FIG. 17, at a position of a turning angle of ±90°, the height of the vertical displacement pattern 204d2 is the largest, the height of the vertical displacement pattern 204d3 is the smallest, and the height of the vertical displacement pattern 204d1 is intermediate therebetween. Therefore, by applying any one of the vertical displacement patterns 204d1, 204d2, and 204d3 depending on the position of the shoulder S of the person M to be imaged, the X-ray detection unit 44 can avoid contact with the shoulder S within a range. Panoramic X-ray imaging can be performed by bringing the X-ray detecting section 44 closer to the head P while minimizing the vertical displacement of the X-ray detecting section 44. In the illustrated example, since the position of the shoulder S is higher than the vertical displacement pattern 204d3 at a position of a turning angle of ±90°, either the vertical displacement pattern 204d1 or 204d2 is selected.

The height of the X-ray detector 44 relative to the head P when the X-ray detector 44 is in front of the head P is the height FH, and the height of the The height of the line detection unit 44 relative to the head P is defined as the height SH. The difference between height FH and height SH is defined as height difference FS. Therefore, the vertical displacement pattern 204d2 has a larger height difference FS than the vertical displacement pattern 204d3, and the vertical displacement pattern 204d3 has a smaller height difference FS than the vertical displacement pattern 204d2.

When the vertical displacement information 204d includes a plurality of vertical displacement patterns 204d1, 204d2, and 204d3, in step S24, the user observes the physique, etc., and inputs settings to determine which vertical displacement pattern 204d1, 204d2, 204d3 is to be applied. , or input the amount of vertical displacement. In step S25, depending on the selected pattern, the vertical displacement patterns 204d1, 204d2, and 204d3 are read out and set as vertical displacement patterns, or a vertical displacement pattern is set according to the input vertical displacement amount. In this way, the setting of the height difference in the orbit R of the X-ray detector 44 can be changed.

In step S26, similarly to step S4, it is determined whether or not the start of imaging has been accepted. If it is determined that no photography has been accepted, the process returns to step S22 and the processes from step S22 onwards are repeated. If it is determined that photography is accepted, the process advances to step S27.

In step S27, panoramic X-ray photography is performed while the X-ray detection unit 44 is rotated according to the set orbit. That is, according to the set first orbit information 104b or second orbit information 104c, the rotation mechanism 62 and the axis movement mechanism 70 are controlled to move the X-ray detection unit 44 to the first orbit R1 or the second orbit R1. Turn along R2. At this time, if a vertical displacement pattern has been set, the vertical drive unit 82 is controlled to move the swing arm 40 in the vertical direction in synchronization with the rotation of the X-ray detection unit 44, and the The line detection section 44 is displaced up and down. At this time, it is preferable to control the holding part driving part 36 to displace the subject holding part 32 in the opposite direction to the moving direction of the rotating arm 40, thereby keeping the height position of the subject holding part 32 constant. Thereby, X-ray imaging data is obtained. The image processing device 180 generates a panoramic X-ray image based on the X-ray imaging data.

When the X-ray detection unit 44 is vertically displaced according to the vertical displacement patterns 204d1, 204d2, and 204d3, an oblique panoramic X-ray image is generated in which an area gradually moving upward from the front to the rear is reflected in a side view. be done. Since the dental arch Arc extends gradually upward from the front to the rear when viewed from the side, the dental arch Arc can be sufficiently reflected even in an oblique panoramic X-ray image.

<Example of panoramic X-ray photography>
As shown in FIG. 18, an example of panoramic X-ray imaging will be described using imaging subjects M(1), M(2), and M(3) who have different physiques as an example. The photographic subjects M(1) and M(2) have different heights, and the height H(1) of the photographic subject M(1) is the height H(2) of the photographic subject M(2). ) is greater than. The subjects M(1) and (2) to be photographed have shoulders S(1) and S(2) that are downward in a standard manner with respect to the head P. The height H(3) of the photographic subject M(3) is greater than the heights H(1) and H(2) of the photographic subjects M(1) and M(2). The shoulder S(3) of the photographic subject M(3) is an angry shoulder. The relative position of the shoulder S(3) with respect to the head P of the photographic subject M(3) is the relative position of the shoulder S(1), S(2) with respect to the head P of the photographic subject M(1), M(2). It is located above the relative position.

Consider a case where the X-ray detection unit 44 is rotated along the first orbit R1 to perform panoramic X-ray photography.

When the imaging subject M(1) is targeted, the X-ray detection unit 44 passes through a position away from the head P also on the side of the head P, as shown in FIG. At a position away from the side of the head P along the first turning trajectory R1, the shoulder S(1) is located below the chin of the head P and the like. Therefore, the X-ray detection unit 44 is unlikely 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 rotating the X-ray detector 44 around the head P without vertically displacing the X-ray detector 44.

When the subject M(2) is the object, as shown in FIG. 20, the X-ray generating section 42 and the X-ray detecting section 44 are held according to the height H(2) of the subject M(2). The rotating arm 40 and the subject holding section 32 are positioned lower than in the case shown in FIG. 19 . In this state, panoramic X-ray photography can be performed as in the case shown in FIG.

When the subject M(3) is the subject of imaging, as shown in FIG. 21, the X-ray detection unit 44 passes through a position away from the head P even to the side of the head P. If the subject M(3) has a physique such as broad shoulders, the shoulders S(3) may be located near the height of the chin or the like of the head P even at a position away from the side of the head P(1) according to the first rotation trajectory R1.

In this case, the X-ray detector 44 may come into contact with the shoulder S(3) on the side of the head P (see the position of the X-ray detector 44(L) in FIG. 21). In such a case, with the X-ray detector 44 located on the side of the head P, move the X-ray detector 44 to a height position (X-ray detector 44(H)) that does not contact the shoulder S(3). It is also conceivable to perform panoramic X-ray imaging without vertically displacing the camera in the state where it is placed at the lowest position (see the lowest end position). However, in this case, the lowermost end of the X-ray detection unit 44 is located above the chin, and the lower front end of the dental arch Arc may not be visible in the panoramic X-ray image.

Therefore, a vertical displacement pattern is set as described in steps S24 and S25 above, and the X-ray detection unit 44 is vertically displaced as described in step S27 so that the X-ray detection unit 44 is lower in front of the head P and higher to the side of the head P. This allows the X-ray detection unit 44 to rotate along the first rotation orbit R1 while avoiding the X-ray detection unit 44 from contacting the shoulder S. This allows a panoramic X-ray image to be generated that captures the anterior lower end of the dental arch Arc while avoiding the X-ray detection unit 44 from contacting the shoulder S(3).

Consider a case where the X-ray detection unit 44 is rotated along the second orbit R2 to perform panoramic X-ray photography.

FIG. 22 shows a case in which the subject to be photographed M(1) is targeted. The X-ray detection unit 44 passes through a position closer to the head P than in the case shown in FIG. 22 on the side of the head P. In this position, if the shoulder S(1) is below the chin, etc., the X-ray detector 44 will come into contact with the shoulder S(1) even at the lateral position of the head P where the X-ray detector 44 passes. There is a possibility that it will not. In this case, panoramic X-ray imaging can be performed by rotating the X-ray detecting section 44 around the head P without vertically displacing the X-ray detecting section 44.

However, it is assumed that the passing position of the X-ray detection unit 44 on the side of the head P is very close to the upper surface of the shoulder S(1). In such a case, it is better to displace the X-ray detection unit 44 and the housing upward on the sides of the head P in preparation for the occurrence of a contact state due to a slight movement of the person to be photographed M(1). There may be cases where this is preferable. Further, the upper surface of the shoulder S(1) is shaped to face upward as it approaches the head P. Therefore, the closer the position of the side portion of the head P to the head P in the second orbit R2 is, the more likely the X-ray detection unit 44 will come into contact with the shoulder S(1). Therefore, depending on the second orbit R2 that is set, it may be preferable to displace the X-ray detection section 44 upward on the side of the head P.

In such a case, it is advisable to perform panoramic X-ray photography by vertically displacing the X-ray detection unit 44 so that it is lower in front of the head P and higher to the side of the head P, as in the X-ray detection unit 44 (H) shown in Figure 23.

When photographing subject M(3) is targeted, the X-ray detection unit 44 passes through a position near the side of the head P, as shown in FIG. If the person to be photographed M(3) has a physique with angry shoulders, etc., the height of the shoulder S(3) near the side of the head P according to the second turning trajectory R2 is equal to that of the person to be photographed M(1). The height is closer to the height of the chin of the head P than in the case of the head P. Therefore, the X-ray detection section 44 comes into contact with the shoulder S(3) more easily on the side of the head P (see X-ray detection section 44(L) in FIG. 23).

Therefore, the vertical displacement pattern is set as explained in steps S24 and S25 above, and as explained in step S27, the X-ray detection unit 44 is lowered in front of the head P and lowered in the side of the head P. The X-ray detection section 44 is vertically displaced so that the height becomes higher (see X-ray detection section 44(H)). Thereby, the X-ray detection section 44 can be rotated along the second rotation trajectory R2 while avoiding contact between the X-ray detection section 44 and the shoulder S. Thereby, it is possible to generate a panoramic X-ray image in which the lower front end of the dental arch Arc is reflected while avoiding the X-ray detection unit 44 coming into contact with the shoulder S(3).

In this way, by vertically displacing the X-ray detector 44, and in particular, by vertically displacing the X-ray detector 44 so that it becomes higher on the sides 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 front end portion of the dental arch Arc is reflected while avoiding the detection unit 44 coming into contact with the shoulder S.

Normally, the upper surface of the shoulder S has a shape that faces upward as it goes toward the head P, so the X-ray detection unit 44 rotates along the second orbit R2 rather than the first orbit R1. In this case, the X-ray detection unit 44 is likely to come into contact with the shoulder S. Therefore, when rotating the X-ray detector 44 along the second orbit R2, it is preferable to vertically displace the X-ray detector 44.

In addition, if the second rotation orbit R2 can be selected or adjusted, the X-ray detection unit 44 may be displaced up and down when an orbit closer to the head P is selected or adjusted as the second rotation orbit R2.In addition, the amount of vertical displacement of the X-ray detection unit 44 may be increased when an orbit closer to the head P is selected or adjusted as the second rotation orbit R2.

The X-ray detection section 44 may be vertically displaced in both the first orbit R1 and the second orbit R2. In this case, the amount of vertical displacement of the X-ray detector 44 may be set to be larger in the second orbit R2 than in the first orbit R1.

The amount of vertical displacement may be set based on a detection result from a detection unit that detects the position of the shoulder S. For example, as shown in FIG. 25, the imaging device 22 images the front and side faces of the person M to be photographed. The captured image 220 includes a front image 221 and a side image 222 including the head P and shoulders S. The imaging control unit 202 executes edge extraction processing and the like based on the captured image 220 to extract the upper boundary of the shoulder S and the like. Then, the height position of the shoulder S in the passage area of the set first turning trajectory R1 or second turning trajectory R2 is recognized. Further, the imaging control unit 202 determines, for example, how much the X-ray detection unit 44 should be raised with respect to the height position of the lower end of the X-ray detection unit 44 that is initially set for the person M to be imaged. Calculate whether contact with the object can be avoided. Based on this calculation result, the amount of vertical displacement of the X-ray detector 44 can be determined, and the vertical displacement pattern can be set based on the amount of vertical displacement.

The first turning trajectory R1 may be set as shown in FIG. 9, and the second turning trajectory R2 may be set as shown in FIG. It may be set higher than the proximity. In this case, the height difference FS2 of the second orbit R2 may be made larger than the height difference FS1 of the first orbit R1. Furthermore, depending on the body size, 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 photographic subject M(3) with angry shoulders, the height difference FS2 of the second turning trajectory R2 and the height difference FS1 of the first turning trajectory R1 is higher than for the standard shooting subject M(1) with sagging shoulders. You may try to make the difference larger.

FIG. 26 shows another setting example of the second orbit R2. The first orbit R1 is shown in FIG. 9, and it is assumed that the first orbit R1 shown in FIG. 9 and the second orbit R2 shown in FIG. 26 can be selectively switched.

The second turning trajectory R2 is set to be a trajectory closer to the head surface than the first turning trajectory R1 in front of the head P (at least in front of the center of the head P in the left-right direction). Therefore, the X-ray detection unit 44 rotating on the second orbit R2 can detect X-rays closer to the anterior tooth region of the dental arch Arc, which is the region of interest.

The second orbit R2 is located in front of the head P and has a higher degree of proximity of the X-ray detection unit 44 to the head surface than the first orbit R1. Further, the second orbit R2 has a higher front proximity ratio and a lower side proximity ratio than the first orbit R1.

In a configuration in which the first orbit R1 shown in FIG. 9 and the second orbit R2 shown in FIG. It may be set larger than the difference FS1. As a result, it is possible to cope with the situation, for example, even if the subject to be photographed has a higher degree of anger.

Furthermore, in a configuration in which the first orbit R1 shown in FIG. 9 and the second orbit R2 shown in FIG. 26 are selectively switched, another second orbit R2 may also be selectable. The other second orbit R2 is, for example, the second orbit R2 shown in FIG. 10, and is set so that the height difference of the second orbit R2 shown in FIG. 10 is larger than that of the other orbits. You can. This makes it possible to enhance the variety of approaches to the head P of the person being photographed.

The proximity of the X-ray detection unit 44 to the head surface may be set so that at least a portion of the entire area of the second orbit R2 is larger than the first orbit R1, and the remaining area is equal to or smaller than the first orbit R1.

Note that the configurations described in each of the above embodiments and modified examples can be combined as appropriate as long as they do not contradict each other.

Accordingly, the specification and drawings disclose the following aspects.

The first aspect is a panoramic X-ray imaging device that includes an X-ray generating unit including an X-ray generator, an X-ray detecting unit including an X-ray detector, a supporting unit that supports the X-ray generating unit and the X-ray detecting unit so that the X-ray generating unit and the X-ray detecting unit face each other, a driving mechanism that drives the supporting unit, a subject holding unit that holds a subject, and a rotation control unit that controls the operation of the supporting unit by the driving mechanism so that the X-ray generating unit and the X-ray detecting unit rotate around the head of the subject held by the subject holding unit to perform panoramic X-ray imaging while the head of the subject is positioned between the X-ray generating unit and the X-ray detecting unit, the rotation control unit being configured to be able to set a first rotation orbit and a second rotation orbit as the panoramic rotation orbit of the X-ray detecting unit for the same subject, and the second rotation orbit is an orbit that is closer to the surface of the head in front and to the side of the head than the first rotation orbit.

According to this panoramic X-ray imaging apparatus, by rotating the X-ray detection section along the second orbit, the X-ray detection section can be moved near the surface of the head. Thereby, the resolution of the panoramic X-ray image can be improved. If there is a possibility that the X-ray detector will come into contact with the shoulder, etc. of the person to be imaged on the second orbit, the X-ray detector will be rotated along the first orbit to avoid contact with the person to be imaged. It is possible to perform panoramic X-ray imaging while avoiding this problem.

The second aspect is a panoramic X-ray imaging device according to the first aspect, in which the subject holding unit includes an anterior tooth region fixing unit that fixes the anterior tooth region of the head, and the rotation control unit sets, as the second rotation orbit, an orbit in front of the anterior tooth region fixing unit and closer to the anterior tooth region fixing unit than the first rotation orbit.

Thereby, it is possible to take a panoramic image of the anterior tooth region that is accurately positioned by the anterior tooth region fixing section.

In a third aspect, in the panoramic X-ray imaging device according to the first or second aspect, the drive mechanism includes a rotation mechanism that rotates the support unit around the axis of the rotation shaft unit, and a rotation shaft moving mechanism that moves the rotation shaft unit in a direction intersecting with the axial direction of the rotation shaft unit.

In this case, when the support section is rotated by the rotation mechanism, the rotation trajectory of the X-ray detection section can be changed by moving the rotation shaft section using the rotation axis moving mechanism. Thereby, the X-ray detection section can be rotated by switching between the first orbit and the second orbit.

In a fourth aspect, in the panoramic X-ray imaging apparatus according to any one of the first to third aspects, the rotation control section sets a trajectory that adapts to a standard head shape as the first rotation trajectory. Set.

According to this embodiment, panoramic X-ray imaging can usually be performed using the first rotation orbit. In cases where it is necessary to improve the resolution or in situations where there is no head or shoulder contact, panoramic X-ray imaging can be performed using the second rotation orbit.

A fifth aspect is the panoramic X-ray imaging apparatus according to any one of the first to fourth aspects, wherein the rotation control section is configured to move the head in front of the head as the second rotation trajectory. Set a trajectory that passes through a position within 10 cm from the surface of the part.

As a result, the resolution of the panoramic X-ray image can be further improved by rotating the X-ray detection unit in front of the head along the second panoramic imaging trajectory that is within 10 cm from the head surface. .

A sixth aspect is the panoramic X-ray imaging apparatus according to the fifth aspect, in which the rotation control section sets a position within 10 cm from the surface of the head as the second rotation trajectory. Set the route to take.

According to this aspect, the resolution of the panoramic X-ray image can be further improved by moving the X-ray detection unit closer to within 10 cm from the surface of the head over the entire area and rotating it.

A seventh aspect is the panoramic X-ray imaging apparatus according to the sixth aspect, wherein in the second orbit, a partial trajectory in a front range of the front tooth region of the head is longer than a partial trajectory in other ranges. The trajectory approaches the surface of the head.

In this way, by bringing the X-ray detection unit closer to the anterior tooth region, the resolution of the panoramic X-ray image representing the anterior tooth region can be further improved.

In an eighth aspect, in the panoramic X-ray imaging apparatus according to any one of the first to seventh aspects, the rotation control unit controls the second rotation trajectory for each individual subject according to physique data of the individual. Set.

According to this aspect, the X-ray detection section can be brought as close to the head as possible depending on the physique of the individual.

A ninth aspect is a panoramic X-ray imaging apparatus according to any one of the first to eighth aspects, further comprising a head surface shape detection section that detects a surface shape of the head, and wherein the rotation control section , the second orbit is set according to the detection result of the head surface shape detection section.

Thereby, the second orbit is set according to the detection result of the head surface shape detection section.

In a tenth aspect, in the panoramic X-ray imaging device according to any one of the first to ninth aspects, the rotation control unit sets, as at least one of the first rotation orbit and the second rotation orbit, an orbit in which the distance to the surface of the head on the side of the head is greater than the distance to the surface of the head on the front of the head.

This allows the X-ray detection section to rotate while avoiding contact with the shoulder.

The above description is illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention.

20, 200 X-ray imaging device 22 Imaging device 30 Imaging main body 32 Subject holding section 33 Chin rest 34 Head holder 40 Swivel arm 42 X-ray generating section 43 X-ray generator 44 X-ray detecting section 45 X-ray detector 60 Drive mechanism 62 Swivel mechanism 70 Swivel axis moving mechanism 82 Vertical drive section 100, 202 Imaging control section 104 Memory section 104a, 204a Imaging program 104b First swivel trajectory information 104c Second swivel trajectory information 110 Operation display section 110a Imaging setting reception section 204d Vertical displacement information 204d1 Vertical displacement pattern 204d2 Vertical displacement pattern 204d3 Vertical displacement pattern M Imaging subject P Head Pa Front tooth region R1 First swivel trajectory R2 Second swivel trajectory S Shoulder X1 Swivel axis

Claims (9)

an X-ray generating unit including an X-ray generator;
an X-ray detection unit including an X-ray detector;
a support portion that supports the X-ray generation portion and the X-ray detection portion so that the X-ray generation portion and the X-ray detection portion face each other;
A drive mechanism that drives the support portion;
A subject holding unit that holds a person to be photographed;
a rotation control unit that controls an operation of the support unit by the drive mechanism so that the X-ray generation unit and the X-ray detection unit rotate around the head of the subject held by the subject holding unit to perform panoramic X-ray photography in a state in which the head of the subject is positioned between the X-ray generation unit and the X-ray detection unit;
a head surface shape detection unit for detecting physique data including image data of the head surface and shoulders of the subject;
Equipped with
the rotation control unit is configured to be able to set a first rotation orbit and a second rotation orbit as a panoramic rotation orbit of the X-ray detection unit for the same imaging subject,
the second rotation path is closer to a surface of the head than the first rotation path in the front and sides of the head,
When setting the second rotation trajectory, the rotation control unit sets the second rotation trajectory according to the shoulder position in accordance with the physical data . The panoramic X-ray imaging device according to claim 1,
When the shoulder of the subject to be photographed is higher than a standard position, the rotation control unit is configured to move the shoulder to the standard position on the side of the head within a range closer than the first rotation trajectory. The panoramic X-ray imaging apparatus sets the second orbit so as to take a more detour than a case where the second orbit is in a more detour than in a case where the second orbit is in a more detour than in a case where the second orbit is in a more detour than in a case where the second orbit is in a more distant position. 3. The panoramic X-ray imaging apparatus according to claim 1,
the subject holding portion includes a front tooth region fixing portion that fixes a front tooth region of the head,
The rotation control unit sets, as the second rotation orbit, an orbit in front of the anterior tooth region fixing portion and closer to the anterior tooth region fixing portion than the first rotation orbit. The panoramic X-ray imaging apparatus according to any one of claims 1 to 3 ,
A panoramic view, wherein the drive mechanism includes a pivot mechanism that pivots the support part around an axis of a pivot shaft, and a pivot shaft moving mechanism that moves the pivot shaft in a direction intersecting an axial direction of the pivot shaft. X-ray photography equipment. The panoramic X-ray imaging apparatus according to any one of claims 1 to 4 ,
The panoramic X-ray imaging apparatus, wherein the rotation control unit sets a trajectory adapted to a standard head shape as the first rotation trajectory. The panoramic X-ray imaging apparatus according to any one of claims 1 to 5 ,
In the panoramic X-ray imaging apparatus, the rotation control unit sets, as the second rotation trajectory, a trajectory passing through a position in front of the head and within 10 cm from the surface of the head. The panoramic X-ray imaging device according to claim 6 ,
In the panoramic X-ray imaging apparatus, the rotation control unit sets, as the second rotation trajectory, a trajectory that passes through positions within 10 cm from the surface of the head. The panoramic X-ray imaging device according to claim 7 ,
The second orbit is a panoramic X-ray imaging apparatus, wherein a partial orbit in a front range of the front tooth region of the head is closer to the surface of the head than partial orbits in other ranges. The panoramic X-ray imaging apparatus according to any one of claims 1 to 8 ,
The rotation control unit is configured to set at least one of the first rotation trajectory and the second rotation trajectory to a surface of the head on a side of the head, which is longer than a distance to the surface of the head in front of the head. A panoramic X-ray imaging device that sets a trajectory with a greater distance from the object.

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