Radiation imaging device

Abstract

The present invention provides a radiation imaging device, which comprises: an irradiation part for irradiating radiation; an arm for holding the irradiation part and the image receiving part in a posture in which the irradiation part and the image receiving part are opposite to each other, and can hold the image receiving part in a loadable and detachable manner; a connecting part or a main body for rotatably supporting the arm; a first locking mechanism and a second locking mechanism for locking the rotation of the arm relative to the connecting part or the main body; a light sensor for detecting whether the image receiving part is removed from the arm; and a control part for performing the following control in a state in which the image receiving part is removed from the arm, that is, even if a lock release operation for releasing the lock based on the rotation of the first locking mechanism and the second locking mechanism is performed, the lock is prohibited from being released.

Description

Technical Field

[0001] The present invention relates to a radiation imaging device and a method for controlling the radiation imaging device. Background Art

[0002] A known radiation imaging device includes an arm having an irradiation unit disposed at one end thereof for irradiating radiation. Among radiation imaging devices, a known radiation imaging device includes an arm having two ends, one end of which is provided with the irradiation unit and the other end of which is detachably mounted with an image receiving unit (see Japanese Patent Application Laid-Open No. 2009-39332).

[0003] The radiation imaging device described in Japanese Patent Application Laid-Open No. 2009-39332 includes an arm (referred to as a C-arm, etc.) having a C-shaped side profile. The arm is rotatable relative to the main body of the radiation imaging device supporting the arm. As the arm rotates, the irradiation unit (radiation generator) and image reception unit (imaging unit) provided at each end of the arm are positioned in any desired posture around the subject while maintaining their relative positions.

[0004] Furthermore, in the radiation imaging device described in Japanese Patent Application Laid-Open No. 2009-39332, the weight balance of the arm is adjusted by adjusting the amount of liquid in the weight adjustment tank in order to maintain the irradiation unit (radiation generating device) and the image receiving unit (imaging unit) in a desired posture. In particular, when the image receiving unit (imaging unit) is attached to or detached from the arm, the weight balance of the arm changes dramatically, causing the arm to rotate unintentionally.

[0005] Therefore, in the radiation imaging device described in Japanese Patent Application Laid-Open No. 2009-39332, when the image receiving unit (imaging unit) is detected to be attached or detached relative to the arm, weight balance adjustment is started. Furthermore, the arm cannot be rotated until the weight balance adjustment is completed, and the arm rotation operation is allowed after the weight balance adjustment is completed. Summary of the Invention

[0006] Technical issues to be solved by the invention

[0007] However, the weight balance adjustment mechanism described in Japanese Patent Application Laid-Open No. 2009-39332 requires a weight adjustment tank, liquid, a pump for conveying the liquid, and the like, resulting in a complex structure.

[0008] The technology according to the present invention provides a radiographic apparatus capable of suppressing unintentional rotation of an arm when an image receiving unit is detached without using a complicated mechanism, and a method for controlling the radiographic apparatus.

[0009] Means for solving technical problems

[0010] The first embodiment of the present invention involves a radiation imaging device comprising: an irradiation unit for irradiating radiation; an arm for holding the irradiation unit and the image receiving unit so that the irradiation unit and the image receiving unit receive the radiation irradiated from the irradiation unit and transmitted through the subject are opposite to each other, and the image receiving unit can be held in a loadable and detachable manner; a supporting unit for rotatably supporting the arm; a locking mechanism for locking the rotation of the arm relative to the supporting unit; a first loading and unloading detection unit for detecting whether the image receiving unit is detached from the arm; and a control unit for performing the following control when the first loading and unloading detection unit detects that the image receiving unit is detached from the arm, that is, even if a lock release operation for releasing the lock based on the rotation of the locking mechanism is performed, the lock is prohibited from being released.

[0011] According to the above configuration, when the image receiving unit is detached from the arm, the control unit of the radiographic apparatus controls the device so as to prohibit the release of the lock even if a lock release operation for releasing the lock caused by the rotation of the locking mechanism is performed. Therefore, it is possible to suppress unintentional rotation of the arm when the image receiving unit is detached without using a complicated mechanism.

[0012] The radiation imaging device according to the second embodiment of the present invention is a radiation imaging device according to the first embodiment, wherein the image receiving unit has a detector for detecting a radiation image of the subject by receiving radiation irradiated from the irradiation unit and transmitted through the subject, and the detector is non-detachably built into the frame.

[0013] The radiation imaging device involved in the third embodiment of the present invention is a radiation imaging device involved in the first embodiment, wherein the image receiving unit includes: a detector that detects a radiation image of the subject by receiving radiation irradiated from the irradiation unit and transmitted through the subject; and a housing unit that can detachably accommodate the detector, and the housing unit can be detachably held on the arm.

[0014] The radiation imaging device involved in the fourth aspect of the present invention is provided with, in the radiation imaging device involved in the third aspect, a friction mechanism capable of switching between a first state in which a friction force opposite to the direction of arm rotation acts on the arm and a second state in which the friction force acting on the arm is smaller than that in the first state; and a second loading and unloading detection unit for detecting whether the detector is removed from the accommodating unit, the first loading and unloading detection unit detecting whether the accommodating unit is removed from the arm, and in a state in which the first loading and unloading detection unit detects that the accommodating unit is mounted on the arm and the second loading and unloading detection unit detects that the detector is removed from the accommodating unit, when a lock release operation is performed, the control unit performs the following control, i.e., allows the lock to be released based on the locking mechanism and puts the friction mechanism into the first state.

[0015] Compared to a state in which both the housing portion and the detector are detached from the arm, a change in the weight balance of the arm is smaller when the housing portion is attached to the arm and the detector is detached from the housing portion.

[0016] According to the above configuration, when the housing is attached to the arm and the detector is removed from the housing, the arm's rotation lock is released, and the friction mechanism is set to the first state in which a friction force acts in the direction opposite to the arm's rotation. Thus, the friction force can be used to suppress unintended arm rotation.

[0017] The radiation imaging device according to the fifth aspect of the present invention is a radiation imaging device according to the fourth aspect, wherein when a lock release operation is performed in a state where the first loading and unloading detection unit detects that the accommodating portion is mounted on the arm and the second loading and unloading detection unit detects that the detector is mounted on the accommodating portion, the control unit performs the following control, i.e., allows the lock to be released based on the locking mechanism and puts the friction mechanism into the second state.

[0018] According to the above configuration, when the housing portion is mounted on the arm and the detector is mounted on the housing portion, the arm's rotation lock is released, and the friction mechanism is set to the second state in which the friction force acting on the arm is reduced compared to the first state. This makes it possible to easily rotate the arm about the support axis.

[0019] The radiation imaging device involved in the 6th aspect of the present invention is a radiation imaging device involved in any one of the 3rd to 5th aspects, comprising: a rotation angle limiting mechanism that can switch between a limiting state in which the range of the rotation angle of the arm is limited to a second range narrower than the first range and a restriction release state in which the restriction on the rotation angle is released; and a second loading and unloading detection unit that detects whether the detector is removed from the accommodating unit, and the first loading and unloading detection unit detects whether the accommodating unit is removed from the arm. In a state in which the first loading and unloading detection unit detects that the accommodating unit is mounted on the arm and the second loading and unloading detection unit detects that the detector is removed from the accommodating unit, when a lock release operation is performed, the control unit performs the following control, that is, allows the release of the lock based on the locking mechanism and puts the rotation angle limiting mechanism into the limiting state.

[0020] Compared to a state in which both the housing portion and the detector are detached from the arm, a change in the weight balance of the arm is smaller when the housing portion is attached to the arm and the detector is detached from the housing portion.

[0021] According to the above configuration, when the housing is attached to the arm and the detector is removed from the housing, the arm's rotation lock is released, and the rotation angle limiting mechanism is set to a limited state that limits the arm's rotation angle to a second range narrower than the first range. This prevents the arm from rotating unintentionally.

[0022] In the radiation imaging device according to the seventh aspect of the present invention, in the radiation imaging device according to the sixth aspect, when a lock release operation is performed in a state where the first loading and unloading detection unit detects that the accommodating portion is mounted on the arm and the second loading and unloading detection unit detects that the detector is mounted on the accommodating portion, the control unit performs the following control, i.e., allowing the lock to be released based on the locking mechanism and placing the rotation angle limiting mechanism in a restriction release state.

[0023] According to the above configuration, when the housing portion is mounted on the arm and the detector is mounted on the housing portion, the arm's rotation lock is released, and the rotation angle limiting mechanism is brought into a restriction-released state in which the restriction on the arm's rotation angle is released. Thus, the arm's rotation angle can be set within the first range.

[0024] The radiation imaging device involved in the 8th embodiment of the present invention is a radiation imaging device involved in any one of the 1st to 7th embodiments, wherein the arm is in an arc shape when viewed from the side, and the supporting portion includes a rail portion that supports the arm movably along the arc shape, and the arm can perform orbital rotation with the center of the arc shape as the rotation center by moving relative to the rail portion.

[0025] According to the above configuration, the arm can perform orbital rotation with respect to the rail portion about the center of the arc shape, and thus the irradiation unit and the image reception unit can be rotated about the body axis of the subject.

[0026] The radiation imaging device involved in the 9th embodiment of the present invention is a radiation imaging device involved in any one of the 1st to 8th embodiments, wherein the support portion includes a bearing portion on the other end side of a support shaft having one end fixed to the arm, and the arm can reverse the positions of the irradiation portion and the image receiving portion relative to the subject by rotating around the axis of the support shaft relative to the bearing portion.

[0027] According to the above configuration, the arm is rotatable about the axis of the support shaft relative to the bearing portion, and thus the positions of the irradiation portion and the image reception portion relative to the subject can be reversed.

[0028] In the radiation imaging device involved in the tenth embodiment of the present invention, in the radiation imaging device involved in any one of the first to seventh embodiments, even in a state where the image receiving portion is detected to be mounted on the arm by the first loading and unloading detection portion, while radiation is continuously irradiated from the irradiation portion, the control portion performs the following control, that is, even if a lock release operation for releasing the lock based on the rotation of the locking mechanism is performed, the lock is prohibited from being released.

[0029] According to the above configuration, even when the image receiving unit is mounted on the arm, the arm rotation lock is prohibited from being released even if the unlocking operation is performed during the animation imaging period in which radiation is continuously irradiated from the irradiation unit. Therefore, it is possible to prevent unnecessary radiation from being irradiated to a part other than the target imaging part due to inadvertent rotation of the arm.

[0030] In the control method of a radiation imaging device involved in the 11th embodiment of the present invention, the radiation imaging device includes: a supporting portion that can rotatably support an arm, the arm holds the irradiation portion and the image receiving portion in a posture where the irradiation portion that irradiates radiation and the image receiving portion that receives the radiation irradiated from the irradiation portion and transmitted through the subject are opposite to each other, and can hold the image receiving portion in a detachable manner; and a locking mechanism that locks the rotation of the arm relative to the supporting portion, the control method detects whether the image receiving portion is removed from the arm, and in a state where it is detected that the image receiving portion is removed from the arm, performs the following control, that is, even if a lock release operation for releasing the lock based on the rotation of the locking mechanism is performed, the lock is prohibited from being released.

[0031] According to the above configuration, when the image receiving unit is removed from the arm, control is performed such that even if a lock release operation is performed to release the lock caused by the rotation of the locking mechanism, release of the lock is prohibited. Therefore, it is possible to suppress unintentional rotation of the arm when the image receiving unit is removed without using a complicated mechanism.

[0032] Effects of the Invention

[0033] According to the technology of the present invention, it is possible to suppress the arm from being inadvertently rotated when the image receiving unit is detached without using a complicated mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is an overall perspective view showing the radiation imaging device according to the first embodiment.

[0035] Figure 2A It is a side view of the radiation imaging device according to the first embodiment.

[0036] Figure 2B It means to make Figure 2A The illustrated diagram is a side view of the radiation imaging apparatus in a state where the arm thereof is rotated in the direction of arrow M1.

[0037] Figure 2C It means to make Figure 2A The illustrated diagram is a side view of the radiation imaging apparatus in a state where the arm thereof is rotated in the direction of arrow M2.

[0038] Figure 3A It is a front view of the radiation imaging device according to the first embodiment.

[0039] Figure 3B It means to make Figure 3A The illustrated diagram is a front view of the radiation imaging apparatus in a state where the arm is rotated in the direction of arrow N1.

[0040] Figure 3C It means to make Figure 3A The illustrated diagram is a front view of the radiation imaging device in a state where the arm is rotated 180° in the direction of arrow N2.

[0041] Figure 4A It is a partial perspective view showing the image receiving section of the radiation imaging device according to the first embodiment.

[0042] Figure 4B yes Figure 4A A cross-sectional view of the image receiving portion shown.

[0043] Figure 5 It is an overall side view showing the locking mechanism of the radiographic apparatus according to the first embodiment.

[0044] Figure 6 It is along Figure 5 Sectional view taken along line AA.

[0045] Figure 7 It is a perspective view showing a first locking mechanism of the radiation imaging device according to the first embodiment.

[0046] Figure 8 It is a perspective view showing the second locking mechanism of the radiation imaging device according to the first embodiment.

[0047] Figure 9 This is a block diagram showing the functional configuration of a control unit of the radiation imaging apparatus according to the first embodiment.

[0048] Figure 10 This is a flowchart showing the processing procedure of the control unit of the radiation imaging apparatus according to the first embodiment.

[0049] Figure 11A It is a partial perspective view showing an image receiving section of a radiation imaging device according to a second embodiment.

[0050] Figure 11B yes Figure 11A A side view of the image receiving portion is shown.

[0051] Figure 12 It is a perspective view showing a first locking mechanism and a first friction mechanism of a radiation imaging device according to a second embodiment.

[0052] Figure 13 yes Figure 12A plan view of the first locking mechanism and the first friction mechanism shown.

[0053] Figure 14 It is a perspective view showing a second locking mechanism and a second friction mechanism of the radiation imaging device according to the second embodiment.

[0054] Figure 15 yes Figure 14 A side view of the second locking mechanism and the second friction mechanism shown.

[0055] Figure 16 This is a block diagram showing the functional configuration of a control unit of a radiation imaging apparatus according to the second embodiment.

[0056] Figure 17 This is a flowchart showing the processing procedure of the control unit of the radiation imaging apparatus according to the second embodiment.

[0057] Figure 18 It is a perspective view showing a rotation angle limiting mechanism of a radiation imaging device according to a third embodiment.

[0058] Figure 19A Yes Figure 18 A front view of the rotation angle limiting mechanism in the restriction released state is shown.

[0059] Figure 19B Yes Figure 18 A front view of the rotation angle limiting mechanism in the restricted state is shown.

[0060] Figure 20 This is a flowchart showing a processing procedure of a control unit of a radiographic imaging device according to a modification.

[0061] Figure 21 It is a partial perspective view showing an image receiving section of a radiation imaging device according to a modified example. DETAILED DESCRIPTION

[0062] Hereinafter, the radiographic imaging apparatus according to the first to third embodiments of the present invention will be described in sequence with reference to the accompanying drawings. In the drawings, arrow X indicates the front-to-back direction of the radiographic imaging apparatus, arrow Y indicates the width direction of the radiographic imaging apparatus, and arrow Z indicates the vertical direction.

[0063] <First embodiment>

[0064] First, use Figures 1 to 10 A radiation imaging device according to a first embodiment of the present invention will be described.

[0065] (Overall Structure of Radiographic Imaging Device)

[0066] Figure 1 The radiographic imaging device 10 of the present embodiment shown is a device for capturing radiographic images of a subject H. The radiographic imaging device 10 is capable of, for example, performing animation photography and still image photography of the subject H. Animation photography is performed, for example, when displaying the treatment target area of the subject H in the form of an animation during surgery (also referred to as fluoroscopic photography, etc.). In animation photography, for example, an animation of the subject H is displayed on a monitor (not shown) that is provided separately from the radiographic imaging device 10. Of course, the captured animation data can also be stored in the memory of the radiographic imaging device 10. Furthermore, in the case of still image photography, the captured still image can also be displayed on the monitor or stored in the memory of the radiographic imaging device 10.

[0067] like Figure 1 As shown, the radiographic imaging device 10 includes an arm 12 (referred to as a C-arm, etc.) having a C-shaped (arc-shaped) side surface, a connecting portion 14 serving as a support portion for rotatably supporting the arm 12, and a main body 16. In the following, the side of the radiographic imaging device 10 where the arm 12 is provided is referred to as the front of the radiographic imaging device 10, and the side where the main body 16 is provided is referred to as the rear of the radiographic imaging device 10.

[0068] (Arm structure)

[0069] The arm 12 has two ends. An irradiation unit 18 is provided at one end of the arm 12, and an image receiving unit 20 is provided at the other end. The arm 12 can hold the irradiation unit 18 and the image receiving unit 20 in a posture in which the irradiation unit 18 and the image receiving unit 20 are opposite to each other. A gap is ensured between the irradiation unit 18 and the image receiving unit 20 so that the subject H and the bed S on which the subject H lies supine can be inserted. In addition, in the following, in the side view (in Figure 1 When referring to the arm 12 (direction viewed from the Y direction), with the arm 12 as a reference, the direction in which the irradiation unit 18 and the image receiving unit 20 are provided is sometimes referred to as the front of the arm 12 and the side of the arm 12 is sometimes referred to as the rear of the arm 12.

[0070] like Figure 2A As shown, the arm 12 is provided so as to be rotatable about an axis M (an axis parallel to the Y axis) relative to a rail portion 22B provided on the connecting portion 14 constituting the support portion. Furthermore, the arm 12 is provided so as to be rotatable about an axis N (an axis parallel to the X axis) relative to a bearing portion 23 provided on the main body portion 16 constituting the support portion.

[0071] Specifically, the rail portion 22B has an arc shape having the same radius as the arc of the arm 12. On the other hand, a fitting portion 22A that fits with the rail portion 22B is provided on the outer peripheral surface of the arm 12. The fitting portion 22A has an arc shape along the shape of the arm 12. Figure 6As shown, the rail portion 22B is, for example, groove-shaped, and the convex fitting portion 22A fits in. Furthermore, a roller (not shown) is inserted between the rail portion 22B and the fitting portion 22A to assist the sliding of the fitting portion 22A relative to the rail portion 22B.

[0072] like Figure 2A As shown, the fitting portion 22A formed on the arm 12 slides along the rail portion 22B formed on the connection portion 14. Thus, the arm 12 is provided with an orbital rotation relative to the connection portion 14 and the main body 16 about the axis M of the arc center of the arm 12 as the rotation center.

[0073] That is, Figure 2B and Figure 2C As shown, the arm 12 is configured to move in the direction of arrow M1 around the axis M ( Figure 2B in the counterclockwise direction) and the direction of arrow M2 ( Figure 2C Thus, the irradiation unit 18 and the image receiving unit 20 provided at both ends of the arm 12 can be rotated around the subject H (reference Figure 1 )'s body axis (an axis parallel to the Y axis).

[0074] And, as Figure 2A As shown, one end of a support shaft 24 extending in the front-back direction (X direction) of the radiographic imaging device 10 is fixed to the arm 12. The other end of the support shaft 24 is supported on the main body 16 via a bearing 23. The support shaft 24 rotates relative to the bearing 23 about the axis N, as shown in FIG. Figure 3A to Figure 3C As shown, the arm 12 and the connection portion 14 are provided so as to be rotatable relative to the main body portion 16 about the axis N of the support shaft 24 as the rotation center.

[0075] That is, Figure 3B and Figure 3C As shown, the arm 12 is configured to move around the axis N in the direction of the arrow N1 ( Figure 3B counterclockwise in the direction of arrow N2) or in the direction of arrow N2 ( Figure 3C Thus, the irradiation unit 18 and the image receiving unit 20 provided at both ends of the arm 12 can be rotated relative to the subject H (reference Figure 1 ) is reversed in the up-down direction (Z-axis direction).

[0076] Among them, about Figure 3A The arm 12 is in a position where the irradiation unit 18 is arranged above the image receiving unit 20, and the radiation tube 32 (see FIG. Figure 1 ) is located above the subject H. Therefore, this posture is called an outer tube posture, etc. Figure 3CIn the illustrated posture of the arm 12 , the irradiation unit 18 is disposed below the image receiving unit 20 , and the radiation tube 32 is located below the subject H. Therefore, this posture is called a down-tube posture.

[0077] Compared with the lower tube posture, the outer tube posture can expand the distance between the irradiation part 18 and the subject H (refer to Figure 1 ) between the two sides. Thus, in the over-tube posture, a relatively wide area can be imaged. Therefore, the over-tube posture is mainly used when capturing a still image of the subject H. On the other hand, in the down-tube posture, the radiation irradiated from the irradiation unit 18 is partially shielded by the bed S and the like. Thus, in the down-tube posture, the radiation irradiation on the subject H (reference Figure 1 Therefore, the tube-down posture is used when capturing a moving image of the subject H by continuously irradiating radiation.

[0078] (Structure of the main body)

[0079] like Figure 1 As shown, the main body 16 of the radiographic imaging device 10 has a plurality of casters 26 mounted on its lower portion, and is configured to be movable within, for example, an operating room or a hospital ward by being pushed manually by an operator.

[0080] The main body 16 includes a control unit 28 for controlling various units of the radiation imaging device 10, such as the irradiation unit 18, and a touch-panel operation panel 30. The configuration of the control unit 28 will be described in detail later.

[0081] The operation panel 30 functions as an operation unit for operating various components of the radiographic apparatus 10, such as the irradiation unit 18, by inputting operation commands thereto. Furthermore, the operation panel 30 functions as a display unit for displaying various information, such as warning messages and radiographic images output from the image receiving unit 20. In addition, the main body 16 includes various switches (not shown), such as a power switch for the radiographic apparatus 10, and a power supply circuit and battery for supplying power to the various components of the radiographic apparatus 10.

[0082] (Structure of Irradiation Section)

[0083] The irradiation unit 18 includes a radiation source 31 and an irradiation field limiter 34. The radiation source 31 includes a radiation tube 32 that generates radiation. The radiation is, for example, X-rays. The radiation tube 32 generates radiation by causing electrons generated from a cathode to collide with a target (anode). The location where the electrons collide with the target becomes the focal point of the irradiated radiation.

[0084] Furthermore, an irradiation field limiter 34 is provided below the radiation source 31. The irradiation field limiter 34 (also referred to as a collimator, etc.) has a rectangular irradiation opening 34A. The radiation generated in the radiation tube 32 is irradiated to the subject H through the irradiation opening 34A. The irradiation field limiter 34 is capable of adjusting the opening area of the irradiation opening 34A. The irradiation field limiter 34 has, for example, four shielding plates (not shown) for shielding the radiation. Each side of the four shielding plates corresponds to a side of the irradiation opening 34A and defines the irradiation opening 34A. By changing the position of the shielding plates, the opening area of the irradiation opening 34A is adjusted, thereby changing the irradiation field of the radiation irradiated from the irradiation unit 18.

[0085] Furthermore, the irradiation section 18 is provided so as to be able to extend in the width direction (in the width direction) of the radiation imaging device 10 relative to the arm 12. Figure 1 Specifically, a pair of mounting plates 38 (in the Y direction) are fixed to one end of the arm 12. Figure 1 Only one of them is shown in the figure).

[0086] A pair of mounting plates 38 are arranged to sandwich both sides of the irradiation unit 18 in the width direction and are connected to both side surfaces of the irradiation unit 18 in the width direction. A rotation shaft 36 is provided protruding from each side surface of the irradiation unit 18 that faces each mounting plate 38. The rotation shaft 36 is supported by each of the mounting plates 38 via bearings (not shown). This allows the irradiation unit 18 to rotate relative to the mounting plates 38 about the axis of the rotation shaft 36, thereby changing the orientation of the irradiation opening 34A of the irradiation unit 18 in the front-to-back direction of the arm 12. Changing the orientation of the irradiation opening 34A can change the direction of the radiation.

[0087] Furthermore, one end of a plurality of cables 40 is connected to the irradiation unit 18. The plurality of cables 40 are wired with signal lines for transmitting control signals and power supply lines. Figure 6 As shown, the cable 40 is disposed on a hollow portion 42 formed in the arm 12 and extends along the arm 12. In addition, the other end of the cable 40 is connected to the Figure 1 The control unit 28 of the main body 16 shown and a power supply circuit (not shown) are connected.

[0088] (Structure of Image Receiving Unit)

[0089] like Figure 1 As shown, the image receiving unit 20 is provided at the other end of the arm 12, opposite the irradiation unit 18. In this embodiment, the image receiving unit 20 includes a detector built into the housing so as to be non-detachable. The image receiving unit 20 includes an image receiving surface 20A for receiving radiation emitted from the irradiation unit 18 and transmitted through the subject H. The radiation, which carries information about the subject H, is incident on the image receiving surface 20A.

[0090] The detector receives radiation irradiated from the irradiation unit 18 and transmitted through the subject H, thereby detecting a radiographic image of the subject H. The detector is, for example, a flat panel detector (FPD) of a digital radiography (DR) system.

[0091] The FPD has a detection surface in which a plurality of pixels are arranged two-dimensionally and a thin film transistor (TFT; thin film transistor) panel (not shown) for driving the pixels. Radiation is incident on the detection surface of the detector through the image receiving surface 20A. The detector converts the incident radiation into an electrical signal and outputs a radiation image representing the subject H based on the converted electrical signal. As a detector, for example, an indirect conversion type is used, which converts radiation into visible light through a scintillator and converts the converted visible light into an electrical signal. In addition, as a detector, a direct conversion type that directly converts radiation into an electrical signal can be used. In addition, as the image receiving unit 20, a structure other than the structure using the FPD can be used, for example, a structure combining an image intensifier (II; Image Intensifier) and a camera can also be used.

[0092] And, as Figure 4A and Figure 4B As shown, the image receiving unit 20 is provided as a movable type detachably mounted on the arm 12. Such a movable image receiving unit 20 is called an electronic cassette, etc. The image receiving unit 20 is detachably mounted on a base 44 provided at the other end of the arm 12.

[0093] Specifically, a base 44 is provided on the upper surface of the other end of the arm 12, and a fitting protrusion 46 is provided upright on the base 44. The base 44 and the fitting protrusion 46 are each rectangular parallelepiped-shaped, and the width (length in the Y direction) of the fitting protrusion 46 is narrower than the width (length in the Y direction) of the base 44.

[0094] On the other hand, the image receiving portion 20 is in the shape of a flat rectangular parallelepiped, and a fitting recess 48 is formed on the lower surface of the image receiving portion 20 to fit with the fitting protrusion 46. The fitting recess 48 is in the shape of a rectangular parallelepiped, and the length in the short side direction ( Figure 4A The length in the Y direction in FIG. 4 is wider than the width of the fitting protrusion 46 and narrower than the width of the base 44. Furthermore, the height of the fitting recess 48 is substantially the same as the height of the fitting protrusion 46.

[0095] Furthermore, the length of the longitudinal direction of the fitting recess 48 ( Figure 4AThe length in the X direction (in the X direction) is longer than the length of the base 44 and the fitting protrusion 46 (the length in the X direction). One end of the fitting recess 48 in the longitudinal direction extends to one side surface of the image receiving unit 20. Since one end of the fitting recess 48 is located on one side surface of the image receiving unit 20, a portion of the one side surface of the image receiving unit 20 is open.

[0096] When the image receiving unit 20 is mounted on the arm 12, the image receiving unit 20 is moved in the horizontal direction (X direction), and the fitting protrusion 46 provided upright on the base 44 is inserted into the fitting recess 48 through an opening formed on one side surface of the image receiving unit 20. Thus, with the fitting protrusion 46 fitted into the fitting recess 48, the lower surface of the image receiving unit 20 abuts against the upper surface of the base 44.

[0097] A pair of positioning pins 50 are provided on the other end face in the longitudinal direction of the fitting recess 48, projecting toward the interior of the fitting recess 48. Meanwhile, a pair of pin holes 52 are formed on one side of the fitting protrusion 46, which faces the other end face in the longitudinal direction of the fitting recess 48, into which the positioning pins 50 are inserted when the fitting recess 48 and the fitting protrusion 46 are fitted. When the fitting recess 48 and the fitting protrusion 46 of the image receiving unit 20 are fitted, the pair of positioning pins 50 are respectively inserted into the pair of pin holes 52, thereby positioning and attaching the image receiving unit 20 to the base 44, i.e., the other end of the arm 12.

[0098] Furthermore, a through-hole 54 extending in the vertical direction (Z direction) is formed on the upper surface of the base 44, and a solenoid 56 is provided below the through-hole 54 at the other end of the arm 12. Furthermore, an insertion hole 58 having a diameter substantially the same as that of the through-hole 54 is formed on the lower surface of the image receiving unit 20. When the image receiving unit 20 is positioned and mounted on the base 44, the insertion hole 58 of the image receiving unit is formed at a position communicating with the through-hole 54 of the base 44.

[0099] The solenoid 56 includes a movable iron core 56A inserted into the through-hole 54 , and the movable iron core 56A is configured to be expandable and contractible by switching between an energized state and a de-energized state of the solenoid 56 .

[0100] Specifically, when the solenoid 56 is energized, the movable iron core 56A is attracted to the main body side of the solenoid 56. Figure 4A As shown, the front end of the movable iron core 56A is located in the through hole 54 of the base 44. In this state, the movable iron core 56A is not inserted into the insertion hole 58 of the image receiving unit 20, so the image receiving unit 20 is attachable to and detachable from the base 44, ie, the arm 12.

[0101] On the other hand, when the insertion hole 58 of the image receiving unit 20 is in communication with the through hole 54 of the base 44, that is, when the image receiving unit 20 is positioned and mounted on the other end of the arm 12, as shown in FIG. Figure 4B As shown, the movable iron core 56A can be inserted into the insertion hole 58 of the image receiving portion 20 .

[0102] Therefore, when the power to the solenoid 56 is cut off while the image receiving unit 20 is positioned and attached to the other end of the arm 12, the distal end of the movable iron core 56A is inserted into the insertion hole 58 and reaches into the image receiving unit 20. In this state, the movable iron core 56A of the solenoid 56 is also inserted into the insertion hole 58 of the image receiving unit 20, thereby restricting removal of the image receiving unit 20 from the base 44, i.e., the arm 12. Thus, when the image receiving unit 20 is attached to the arm 12, the solenoid 56 constitutes an attachment and detachment restriction mechanism that restricts inadvertent attachment and detachment of the image receiving unit 20 from the arm 12.

[0103] Furthermore, a light sensor 60 is provided on the base 44 as a first attachment / detachment detection unit for detecting whether the image receiving unit 20 has been detached from the arm 12. The light sensor 60 is, for example, a reflective sensor having a light emitting window for emitting light from a light emitting element (not shown) and a light receiving window for receiving light from a light receiving element (not shown) arranged on the same surface. In the light sensor 60, when the image receiving unit 20 is not attached to the base 44, the light emitting window and the light receiving window are exposed to the outside. On the other hand, when the image receiving unit 20 is attached to the base 44, the light sensor 60 is provided at a position where the light emitting window and the light receiving window are covered by the image receiving unit 20.

[0104] For example, the optical sensor 60 of this embodiment is directed toward Figure 4A The optical sensor 60 is configured with the upper surface thereof in the middle position. In the optical sensor 60, when the base 44 is attached to the image receiving unit 20, light emitted from the light-emitting window is reflected by the image receiving unit 20. Consequently, the amount of light received through the light-receiving window increases. On the other hand, when the image receiving unit 20 is removed from the base 44 and retracted from the front of the light-emitting window and the light-receiving window, light is no longer reflected by the image receiving unit 20. Consequently, the amount of light received through the light-receiving window decreases.

[0105] In this manner, the optical sensor 60 can detect whether the image receiving unit 20 is detached from the arm 12 by detecting a change in the light emitted from the light emitting window and received by the light receiving element.

[0106] When the optical sensor 60 detects that the image receiving unit 20 is attached to the arm 12, it outputs an on signal as a detection signal to the control unit 28. Furthermore, when the optical sensor 60 detects that the image receiving unit 20 is detached from the arm 12, it outputs an off signal as a detection signal to the control unit 28.

[0107] The mobile image receiving unit 20 includes, for example, a battery and a wireless communication unit (not shown), and is configured to communicate with the control unit 28 (see FIG. 1 ) provided on the main body 16. Figure 1 ) or other wireless communications. When the wireless communication unit is used, the image receiving unit 20 is driven by power from the battery and can be used without cables. Thus, the image receiving unit 20 is configured to be usable in a state detached from the arm 12.

[0108] On the other hand, when the image receiving unit 20 is mounted on the arm 12, Figure 4A The terminal 62A on the fitting recess 48 of the image receiving unit 20 shown in the figure comes into contact with the terminal 62B provided on the fitting protrusion 46 of the arm 12 , thereby electrically connecting the image receiving unit 20 and the base 44 .

[0109] The base 44 is connected to the control unit 28 and the power supply circuit (not shown) of the main body 16 via a cable (not shown) wired with a signal line for transmitting control signals and a power supply line. Thus, when the image receiving unit 20 is attached to the arm 12, the image receiving unit 20 is connected to the control unit 28 and the power supply circuit (not shown) via the cable (not shown).

[0110] (Structure of the first locking mechanism)

[0111] like Figure 5 As shown, the radiographic imaging device 10 is provided with a first locking mechanism 64 and a second locking mechanism 76, which are locking mechanisms for locking the rotation of the arm 12. The first locking mechanism 64 is provided on the connecting portion 14 and locks the orbital rotation of the arm 12, that is, the rotation of the arm 12 relative to the rail portion 22B.

[0112] The two ends of the synchronous belt 66 are fixed to the two ends of the arm 12. The arm 12 is composed of a cylindrical body with a cavity inside. Figure 6 As shown, a timing belt 66 and a cable 40 are disposed in the hollow portion 42 within the arm 12. A groove 42A extending along the arc of the arm 12 is formed on the inner side surface of the hollow portion 42, located at the front side of the arm 12. The timing belt 66 extends along the arc of the arm 12 while being accommodated in the groove 42A. This prevents interference between the cable 40 and the timing belt 66 within the hollow portion 42.

[0113] Furthermore, the timing belt 66 is wound around a timing pulley 68 provided on the connecting portion 14 between one end and the other end of the arm 12. Figure 7As shown, a plurality of teeth 66A are formed on the timing belt 66, and a plurality of grooves 68A are formed on the outer peripheral surface of the timing pulley 68. The timing belt 66 and the timing pulley 68 are linked by the engagement of the teeth 66A of the timing belt 66 with the grooves 68A of the timing pulley 68.

[0114] Furthermore, idler pulleys 70 are provided vertically (in the Z direction) above and below the timing pulley 68 in the connection portion 14. The timing belt 66 is guided by the pair of idler pulleys 70 while being maintained at a predetermined tension and is wound around the timing pulleys 68.

[0115] When the arm 12 is relative to the rail portion 22B (refer to Figure 5 ) When the track rotates, the timing belt 66 follows the movement of the arm 12. For example, if one end of the arm 12 moves away from the connecting portion 14 (track portion 22B), the timing belt 66 moves to Figure 7 The arrow P direction in the figure indicates that one end moves away from the connecting portion 14. At this time, the synchronous pulley 68 engaged with the synchronous belt 66 moves along the arrow Q direction ( Figure 7 (clockwise in the direction of rotation).

[0116] In this embodiment, a first locking mechanism 64 is connected to the timing pulley 68. The first locking mechanism 64 is, for example, a non-excitation electromagnetic brake, which locks rotation when power is off and releases the rotation lock when power is on. By using a non-excitation electromagnetic brake as the first locking mechanism 64, the rotation of the arm 12 is locked when power to the first locking mechanism 64 is cut off, such as during a power outage, thereby preventing the arm 12 from rotating unintentionally.

[0117] Specifically, the first locking mechanism 64 includes a housing 72 having an electromagnet (not shown) built in, and a rotating shaft 74 mounted on the housing 72 via a rotor (not shown) disposed within the housing 72. The housing 72 is fixed to the connecting portion 14 in a non-rotatable manner. Meanwhile, the rotor and the rotating shaft 74 are rotatably supported by the connecting portion 14 via a bearing (not shown). Furthermore, the timing pulley 68 is coaxially rotatably fixed to the rotating shaft 74.

[0118] Although not shown in the figure, the electromagnet and the rotor are arranged around the rotating shaft 74, and the electromagnet and the rotor are opposed to each other in the axial direction of the rotating shaft 74. Furthermore, a movable iron piece is provided between the electromagnet and the rotor within the housing 72, and is movable in the axial direction of the rotating shaft 74. The movable iron piece is arranged separately from the electromagnet, and is biased toward the rotor by a biasing member (not shown) to press the rotor against the inner wall surface of the housing 72.

[0119] When the first locking mechanism 64 is de-energized, the rotor is pressed against the inner wall of the housing 72 by the movable iron piece. Consequently, the rotor's rotation relative to the housing 72 is locked. Furthermore, by locking the rotor's rotation relative to the housing 72, the rotation of the rotating shaft 74 fixed to the rotor and the timing pulley 68 fixed to the rotating shaft 74 are also locked. Furthermore, the movement of the timing belt 66 meshing with the timing pulley 68 is also locked.

[0120] The ends of the timing belt 66 are fixed to the ends of the arm 12. Therefore, the movement of the timing belt 66 is locked, and the arm 12 is fixed relative to the rail portion 22B (refer to FIG. Figure 5 )'s orbital rotation is locked.

[0121] On the other hand, when power is supplied to the first locking mechanism 64, a magnetic force is generated in the electromagnet built into the housing 72, causing the movable iron piece to be attracted toward the electromagnet against the force applied by the biasing member. This releases the pressure exerted by the movable iron piece on the rotor against the inner wall of the housing 72, allowing the rotor to rotate relative to the housing 72. In other words, the rotation lock on the rotor is released.

[0122] Furthermore, by releasing the rotation lock of the rotor, the rotation lock of the rotating shaft 74 and the timing pulley 68 is also released. Furthermore, the timing belt 66 meshed with the timing pulley 68 can move. As a result, the arm 12 is moved relative to the rail portion 22B (refer to FIG. Figure 5 )'s orbital rotation lock is released.

[0123] (Structure of the Second Locking Mechanism)

[0124] like Figure 5 As shown, the second locking mechanism 76 is provided on the main body 16 and locks the axial rotation of the arm 12, that is, the rotation relative to the bearing portion 23. Figure 8 As shown, the second locking mechanism 76 is attached to the other end of the support shaft 24 .

[0125] Similar to the first locking mechanism 64 described above, the second locking mechanism 76 is, for example, a non-excitation-operated electromagnetic brake. The second locking mechanism 76 includes a housing 78 fixed to the main body 16 in a non-rotatable manner, and a rotating shaft 80 rotatably mounted to the housing 78 via a rotor (not shown). The support shaft 24 is coaxially rotatably fixed to the rotating shaft 80.

[0126] When the second locking mechanism 76 is de-energized, the rotor is pressed against the inner wall of the housing 78 by a movable iron piece (not shown). Consequently, the rotor is locked from rotating relative to the housing 78. Furthermore, by locking the rotor's rotation relative to the housing 78, the rotation of the rotating shaft 80 fixed to the rotor and the support shaft 24 fixed to the rotating shaft 80 are also locked. By locking the rotation of the support shaft 24, the axial rotation of the arm 12 relative to the bearing 23 is also locked.

[0127] On the other hand, when power is supplied to the second locking mechanism 76, a magnetic force is generated by the electromagnet (not shown) built into the housing 78, attracting the movable iron piece (not shown) toward the electromagnet. This releases the pressure exerted by the movable iron piece on the rotor against the inner wall of the housing 78. Furthermore, the rotor becomes rotatable relative to the housing 78. In other words, the rotation lock on the rotor is released.

[0128] Furthermore, by releasing the rotation lock of the rotor, the rotation lock of the rotating shaft 80 and the support shaft 24 fixed to the rotating shaft 80 is also released. Thus, the lock of the axial rotation of the arm 12 with respect to the bearing portion 23 is released.

[0129] (Structure of the control unit)

[0130] like Figure 9 As shown, the radiation imaging device 10 is provided with a main body 16 (refer to Figure 1 ) sends a control signal to the radiation tube 32 of the irradiation unit 18 to control the tube voltage, tube current, and radiation irradiation time of the radiation tube 32. The energy of the radiation is controlled by controlling the tube voltage. Furthermore, the dose of the radiation is controlled by controlling the tube current and irradiation time. In practice, a high voltage is applied to the radiation tube 32, so the control unit 28 controls the radiation tube 32 through a high voltage generating device not shown. When performing photography, the operation panel 30 (refer to Figure 1 ) to set imaging conditions including tube voltage, tube current, and irradiation time. The control unit 28 operates the irradiation unit 18 according to the set imaging conditions.

[0131] The control unit 28 can make the irradiation unit 18 execute the irradiation for movie photography by continuously irradiating the radiation from the irradiation unit 18 so as to be able to perform the irradiation for movie photography of the subject H (refer to FIG. Figure 1 ) Animation photography of the image. Here, “continuous irradiation with radiation” includes not only continuous irradiation in which radiation is continuously irradiated, but also so-called pulse irradiation in which irradiation is repeated at predetermined minute time intervals.

[0132] During animation photography, the control unit 28 synchronizes the operation of the detectors of the image receiving unit 20 with the animation photography illumination by the illumination unit 18. In the case of animation photography, the illumination time is generally not set as an imaging condition, and commands to start and end animation photography are issued via the operation panel 30. Upon input of a command to start animation photography, the control unit 28 begins irradiating radiation from the illumination unit 18 under the pre-set imaging conditions. Of course, commands to start and end animation photography can also be issued via a foot switch or other means other than the operation panel 30.

[0133] During animation photography, the detector repeatedly performs image detection at a preset frame rate while performing animation illumination. The images output by the detector are sent to the control unit 28. The control unit 28 sequentially outputs the received images to a monitor (not shown). This displays an animation of the subject H on the monitor.

[0134] Furthermore, the control unit 28 can control the subject H (refer to FIG. 1 ) by causing the irradiation unit 18 to execute the irradiation for still image photography in a shorter time than the irradiation for moving image photography. Figure 1 ) still image photography.

[0135] In still image photography, the control unit 28 causes the detector of the image receiving unit 20 to operate in synchronization with the irradiation timing of the still image photography irradiation of the irradiation unit 18. The command for still image photography is issued, for example, through an irradiation switch (not shown) connected to the control unit 28. In the case of still image photography, the irradiation time is, for example, a time amount ranging from tens of milliseconds to hundreds of milliseconds. If the command for still image photography is input, the control unit 28 causes the irradiation unit 18 to operate according to the pre-set photography conditions. In the case of still image photography, the irradiation time is set in the photography conditions. Therefore, when the set irradiation time has passed, the irradiation of the irradiation unit 18 ends.

[0136] When irradiation is completed, the detector begins outputting the detected image. The image output by the detector is sent to the control unit 28. The control unit 28 stores the still image data in a memory (not shown). Furthermore, the stored still image is displayed on a monitor (not shown). Thus, a still image of the subject H is displayed on the monitor. Furthermore, the still image can be displayed on the operation panel 30 to confirm the captured still image immediately after shooting.

[0137] Furthermore, the control unit 28 controls the solenoid 56. That is, in a state where the attachment and detachment of the image receiving unit 20 to the arm 12 are restricted by the solenoid 56, the image receiving unit 20 is controlled via the operation panel 30 (see FIG. Figure 1 ) When the removal restriction is released, the control unit 28 sends a drive signal to the solenoid 56, and energizes the solenoid 56. As a result, the movable iron core 56A (refer to Figure 4B ) is attracted by the solenoid 56, and the image receiving unit 20 can be removed from the arm 12.

[0138] On the other hand, when the operation panel 30 (refer to Figure 1 ) When the image receiving unit 20 is input with a command for restricting attachment and detachment, the control unit 28 cuts off the power to the solenoid 56. At this time, when the image receiving unit 20 is mounted on the arm 12, Figure 4BThe insertion hole 58 of the image receiving unit 20 shown communicates with the through hole 54 of the base 44 . Therefore, the image receiving unit 20 is restricted from being attached to or detached from the arm 12 by inserting the movable iron core 56A into the insertion hole 58 of the image receiving unit 20 .

[0139] In this way, the control unit 28 switches between a state in which the image receiving unit 20 is allowed to be attached to and detached from the arm 12 and a state in which the image receiving unit 20 is restricted from being attached to and detached from the arm 12 by controlling the energization of the solenoid 56. In addition, even when a command to restrict the attachment and detachment of the image receiving unit 20 is input, when the image receiving unit 20 is not attached to the arm 12, that is, when the image receiving unit 20 is not attached to the arm 12, the control unit 28 switches between a state in which the image receiving unit 20 is allowed to be attached to and detached from the arm 12 and a state in which the image receiving unit 20 is restricted from being attached to and detached from the arm 12. Figure 4B When the insertion hole 58 of the image receiving unit 20 shown is not connected to the through hole 54 of the base 44, the movable iron core 56A cannot be inserted into the insertion hole 58. Therefore, attachment and detachment of the image receiving unit 20 to the arm 12 are not restricted.

[0140] Furthermore, the control unit 28 determines whether the image receiving unit 20 is removed from the arm 12 based on the detection signal from the optical sensor 60 provided on the arm 12. Figure 4B As shown, when the image receiving unit 20 is attached to the arm 12, the control unit 28 receives an ON signal as a detection signal from the optical sensor 60. The control unit 28 determines that the image receiving unit 20 is attached to the arm 12 when receiving the ON signal from the optical sensor 60.

[0141] On the other hand, Figure 4A As shown, when the image receiving unit 20 is detached from the arm 12 , the control unit 28 receives an OFF signal as a detection signal from the optical sensor 60 . The control unit 28 determines that the image receiving unit 20 is detached from the arm 12 upon receiving the OFF signal from the optical sensor 60 .

[0142] Furthermore, the control unit 28 controls the first locking mechanism 64 according to the operation command from the operation panel 30. That is, when a lock release command for closing the rotation lock is input through the operation panel 30, the control unit 28 sends a drive signal to the first locking mechanism 64 to energize the first locking mechanism 64. Figure 7 The rotational locking of the illustrated rotating shaft 74 and the timing pulley 68 relative to the housing 72 unlocks the orbital rotation of the arm 12 relative to the rail portion 22B.

[0143] On the other hand, if a lock command for unlocking the rotation lock is inputted through the operation panel 30, the control unit 28 cuts off the power supply to the first locking mechanism 64. Figure 7 The illustrated rotating shaft 74 and the timing pulley 68 are locked in rotation relative to the housing 72 , and the arm 12 is locked in orbital rotation relative to the rail portion 22B.

[0144] Similarly, the control unit 28 controls the second locking mechanism 76 according to the operation signal from the operation panel 30. That is, if the lock release command for closing the rotation lock is input through the operation panel 30, the control unit 28 sends a drive signal to the second locking mechanism 76 to energize the second locking mechanism 76. Figure 8 The rotation lock of the illustrated rotating shaft 80 and the support shaft 24 relative to the housing 78 is released, and the lock of the axial rotation of the arm 12 relative to the bearing portion 23 is released.

[0145] On the other hand, if a lock command for unlocking the rotation lock is inputted through the operation panel 30, the control unit 28 cuts off the power supply to the second locking mechanism 76. Figure 8 The rotation lock of the illustrated rotating shaft 80 and the support shaft 24 relative to the housing 78 is released, and the lock of the axial rotation of the arm 12 relative to the bearing portion 23 is released.

[0146] (Control Method of Radiographic Imaging Device)

[0147] Next, use Figure 10 A control method of the radiation imaging device 10 according to the present embodiment will be described using the flowchart of FIG.

[0148] First, in step S500, when the power is turned on by operating the power switch (not shown) ("Yes" in step S500), the control unit 28 begins controlling the radiographic imaging device 10. Once control by the control unit 28 begins, input of imaging conditions, etc., can be received through the operation panel 30. Furthermore, the first locking mechanism 64 and the second locking mechanism 76 of this embodiment employ non-excitation-operated electromagnetic brakes. Therefore, when the power of the radiographic imaging device 10 is turned off, the rotation of the arm 12 is locked. Therefore, in this embodiment, when the radiographic imaging device 10 is activated, the rotation of the arm 12 is locked.

[0149] In step S502, the control unit 28 determines whether a lock release operation has been performed to release the rotation lock of the arm 12. If no lock release command has been issued in step S502 ("No" in step S502), the process proceeds to step S504, where the rotation lock state of the arm 12 is maintained. In other words, release of the rotation lock of the arm 12 is prohibited. The process then proceeds to step S514.

[0150] In step S502 , when there is a lock release command (“Yes” in step S502 ), the control unit 28 determines whether the image receiving unit 20 is attached to the arm 12 (step S506 ).

[0151] If, in step S506, the control unit 28 determines that the image receiving unit 20 is not attached to the arm 12 ("No" in step S506), the process proceeds to step S504 and maintains the rotation lock state of the arm 12. In other words, the release of the rotation lock of the arm 12 is prohibited. The process then proceeds to step S514.

[0152] In step S506, when the control unit 28 determines that the image receiving unit 20 is mounted on the arm 12 ("Yes" in step S506), the control unit 28 releases the rotation lock of the arm 12 by energizing the first locking mechanism 64 and the second locking mechanism 76 (step S508).

[0153] After releasing the rotation lock of the arm 12 in step S508, the control unit 28 waits until a locking operation is performed to lock the rotation of the arm 12 (step S510). If a lock command is issued ("Yes" in step S510), the control unit 28 locks the rotation of the arm 12 by shutting off power to the first locking mechanism 64 and the second locking mechanism 76 (step S512).

[0154] In step S514, the control unit 28 determines whether the power of the radiographic apparatus 10 has been turned off by the operator operating a power switch (not shown). If the power of the radiographic apparatus 10 has not been turned off ("No" in step S514), the process returns to step S502. On the other hand, if the power of the radiographic apparatus 10 has been turned off ("Yes" in step S514), the control unit 28 terminates control of the radiographic apparatus 10.

[0155] In addition, although Figure 10 Although not shown in the flowchart, in step S508, the power supply to the radiation imaging device 10 may be turned off while the rotation lock of the arm 12 is released. In this case, even if a lock command is not issued via the operation panel 30, the power supply to the first locking mechanism 64 and the second locking mechanism 76 is turned off by turning off the power supply to the radiation imaging device 10, thereby locking the rotation of the arm 12.

[0156] (Effect)

[0157] According to the radiographic apparatus 10 of this embodiment, the first locking mechanism 64 for locking the arm 12 relative to the orbit of the rail portion 22B is provided on the connecting portion 14. Furthermore, the second locking mechanism 76 for locking the arm 12 relative to the axis of the bearing portion 23 is provided on the main body 16.

[0158] Furthermore, in the arm 12 , a photosensor 60 is provided as an example of a first attachment / detachment detection unit on the base 44 to which the image receiving unit 20 is attached. The photosensor 60 can detect whether the image receiving unit 20 has been detached from the arm 12 .

[0159] Furthermore, in this embodiment, the control unit 28 of the radiographic apparatus 10 controls the image receiving unit 20 to be removed from the arm 12 so as to prohibit the arm 12 from being released even if a lock release operation is performed to release the rotation lock of the arm 12 by the first locking mechanism 64 and the second locking mechanism 76. Therefore, it is possible to suppress the arm 12 from being inadvertently rotated when the image receiving unit 20 is removed without using a complex mechanism such as a weight balance adjustment mechanism used in the prior art.

[0160] In the radiation imaging device 10 of this embodiment, two locking mechanisms for the arm 12 are provided: a first locking mechanism 64 for locking the orbital rotation of the arm 12, and a second locking mechanism 76 for locking the axial rotation of the arm 12. Furthermore, the control unit 28 controls the first locking mechanism 64 and the second locking mechanism 76 to prohibit unlocking according to the attachment or detachment state of the image receiving unit 20. Thus, it is preferable to control both locking mechanisms to prohibit unlocking. However, it is not necessary to control both locking mechanisms; it is sufficient to control at least one of the first locking mechanism 64 and the second locking mechanism 76.

[0161] Furthermore, in the radiation imaging device 10 of this embodiment, when it is detected that the image receiving unit 20 has been removed from the arm 12, control is performed to prohibit the release of the lock. However, in addition to this, the following control can also be performed. That is, even when the image receiving unit 20 is mounted on the arm 12, when the image receiving unit 20 loading and unloading restriction based on the solenoid 56 (an example of a loading and unloading restriction mechanism) is in the closed (removable) state, control can be performed such that even if the rotation lock of the arm 12 is released, the release of the rotation lock is prohibited. In this way, the image receiving unit 20 can be prevented from accidentally falling off the arm 12 due to the rotation of the arm 12.

[0162] At this time, the control unit 28 determines whether the image receiving unit 20 is attached based on the detection signal of the photosensor 60 as an example of the first attachment and detachment detection unit, and determines whether the attachment and detachment restriction of the image receiving unit 20 is on or off based on the energization state of the solenoid 56 .

[0163] <Second embodiment>

[0164] Next, using Figure 11~ Figure 17A radiation imaging device according to a second embodiment of the present invention will be described. Components identical to those in the first embodiment will be denoted by the same reference numerals and their description will be omitted, with the description focusing on the differences.

[0165] In the radiation imaging device 10 of the first embodiment, the image receiving unit 20 having the detector built into the housing is detachably mounted on the arm 12. In contrast, in the radiation imaging device 100 of the present embodiment, Figure 11A and Figure 11B As shown, the image receiving unit 106 is composed of a detector 102 and a housing 104 that detachably houses the detector 102 .

[0166] (Structure of Image Receiving Unit)

[0167] The detector 102 is detachably accommodated in the accommodating portion 104, and the accommodating portion 104 is detachably mounted on the arm 12. The meaning of the detector 102 being detachably mounted on the accommodating portion 104 is the same as the meaning of the detector 102 being detachably mounted on the arm 12. Therefore, with this structure, the size of the detector 102 mounted on the arm 12 can be changed.

[0168] Furthermore, the accommodating portion 104 can be attached to and detached from the arm 12. In this way, when the size of the detector 102 is changed, it is easy to maintain the weight balance of the arm 12. The C-arm shown as an example of the arm 12 prevents unintentional orbital rotation by achieving a weight balance between the irradiation portion 18 and the image receiving portion 106 held at both ends, thereby being able to stop at any rotational position. More specifically, the center of rotation of the orbital rotation of the arm 12 (at Figure 2A The center of the arm 12 (which is consistent with the axis M) is consistent with the center of gravity of the entire arm 12 including the irradiation unit 18 and the image receiving unit 106, so that the arm 12 can be stopped at any rotation position through the weight balance of the arm 12.

[0169] If the size of the detector 102 is changed, the weight of the image receiving unit 106 changes, and thus the center of gravity of the arm 12 also deviates from the rotation center of the orbital rotation. Therefore, by making the housing 104 in addition to the detector 102 also detachable relative to the arm 12, the weight change of the detector 102 can be compensated by changing the housing 104. As the housing 104, a plurality of housings with different weights can be prepared, for example, by changing the ballast for weight adjustment. By using these various housings 104 separately, the weight change caused by the size change of the detector 102 can be compensated. Thus, even if the size of the detector 102 is changed, by changing the housing 104 accordingly, the weight balance of the irradiation unit 18 and the image receiving unit 106 can be maintained and the center of gravity of the arm 12 can be made consistent with the center of orbital rotation.

[0170] As with the detector of the first embodiment, the detector 102 constituting the image receiving unit 106 is constituted by, for example, a flat panel detector, and receives images from the image receiving surface 102A. Figure 1 The illustrated irradiation unit 18 irradiates and transmits radiation to the subject H, thereby detecting a radiographic image of the subject H. In the present embodiment, the detector 102 functions as a mobile electronic cassette.

[0171] The accommodating portion 104 constituting the image receiving portion 106 is a flat rectangular parallelepiped box having a fitting recess 108 formed on its lower surface and a accommodating recess 110 for accommodating the detector 102. The fitting recess 108 has the same structure as the fitting recess 48 formed on the lower surface of the image receiving portion 20 in the first embodiment, and the accommodating portion 104 is detachably mounted on the arm 12 by fitting the fitting recess 108 with the fitting protrusion 46 provided at the other end of the arm 12.

[0172] Furthermore, similarly to the first embodiment, the arm 12 is provided with a solenoid 56 for restricting the attachment and detachment of the housing portion 104 relative to the arm 12, and a photosensor 60 serving as a first attachment and detachment detection unit. In this embodiment, the photosensor 60 detects whether the housing portion 104 has been detached from the arm 12, that is, whether both the housing portion 104 and the detector 102 constituting the image receiving portion 106 have been detached from the arm 12.

[0173] like Figure 11A As shown, an opening 110A for accommodating the detector 102 in the accommodating recess 110 is formed on one of the four side surfaces of the accommodating portion 104. Figure 16 ) A square opening 110B communicating with the accommodating recess 110 is also formed on the upper surface of the opposite accommodating portion 104.

[0174] When the detector 102 is accommodated in the accommodating recess 110, as shown in FIG. Figure 11B As shown, the image receiving surface 102A of the detector 102 is exposed from the opening 110B formed on the upper surface of the housing portion 104. Thus, even when the detector 102 is mounted on the housing portion 104, i.e., the arm 12, the image receiving surface 102A of the detector 102 can receive the image from the irradiation portion 18 (see FIG. Figure 16 ) radiation exposure.

[0175] Furthermore, the housing portion 104 is provided with a photosensor 112 as a second attachment and detachment detection unit for detecting whether the detector 102 is detached from the housing portion 104. The photosensor 112 is provided on the side surface of the housing recess 110 opposite to the side surface where the opening 110A of the housing portion 104 is formed.

[0176] The optical sensor 112 has the same structure as the optical sensor 60 of the first embodiment, and can detect the presence or absence of the detector 102 in the accommodating recess 110 by detecting changes in the amount of light emitted by the light-emitting element and received by the light-receiving element. The second attachment and detachment detection unit is not limited to the optical sensor 112; for example, a contact sensor using a piezoelectric element or a microswitch may be used, as long as it has the function of detecting whether the detector 102 has been removed from the accommodating portion 104.

[0177] In addition, in addition to the optical sensor 112 serving as the second loading and unloading detection unit, an unillustrated loading and unloading restriction mechanism may be provided in the accommodating recess 110. The unillustrated loading and unloading restriction mechanism fixes the detector 102 in the accommodating recess 110 to prevent the detector 102 from falling off and releases the prevention state.

[0178] (Structure of the first friction mechanism)

[0179] like Figure 12 and Figure 13 As shown, the connection portion 14 of the radiographic apparatus 100 of this embodiment is provided with a first locking mechanism 64 and a first friction mechanism 114 serving as a friction mechanism.

[0180] The first locking mechanism 64 has the same structure as that of the first embodiment. Specifically, the first locking mechanism 64 includes a housing 72 and a rotating shaft 74, and a timing pulley 68 is fixed to the rotating shaft 74. Furthermore, a timing belt 66 is wound around the timing pulley 68, with both ends fixed to the ends of the arm 12.

[0181] Furthermore, the rotation shaft 74 of the first locking mechanism 64 is connected via Figure 13 The bearing portion 116 shown is rotatably supported by a frame 118 of the connecting portion 14. A first gear 120 is coaxially rotatably fixed to the rotating shaft 74, and a second gear 122 meshes with the first gear 120.

[0182] The first friction mechanism 114 includes a first friction shaft 124 , a friction force generating portion 126 attached to the first friction shaft 124 and generating friction force, and a first electromagnetic clutch 128 that switches between connection and disconnection between the rotating shaft 74 of the first lock mechanism 64 and the first friction shaft 124 .

[0183] like Figure 13 As shown, the first friction shaft 124 is rotatably supported on the frame 118 of the connecting portion 14 via the bearing portion 130. The first friction shaft 124 is inserted into the shaft hole 132A formed on the side plate 132. The side plate 132 is axially ( Figure 13It is fixed on the frame 118 at a distance relative to the frame 118 in the Y direction).

[0184] The friction force generating unit 126 includes two sets of friction plates 134A and 134B that generate friction force through contact between their friction surfaces, and a force applying unit 136 that applies force in a direction that presses the friction surfaces of the friction plates 134A and 134B against each other. One set of friction plates 134A and 134B is provided on each of the axial end surfaces of the first friction shaft 124 on the side plate 132.

[0185] An axial hole (not shown) is formed in each of the friction plates 134A and 134B. By inserting the first friction shaft 124 into the axial hole, the friction plates 134A and 134B are mounted so as to be movable in the axial direction of the first friction shaft 124. Furthermore, the set of friction plates 134A and 134B disposed between the side plate 132 and the frame 118 is restricted in axial movement of the first friction shaft 124 by a restriction plate 138 fixed to the first friction shaft 124.

[0186] Furthermore, friction plate 134A, which contacts the end surface of side plate 132, is fixed by a rotation stopper (not shown), thereby becoming a fixed friction plate that does not rotate regardless of the rotation of first friction shaft 124. Meanwhile, friction plate 134B, which is provided axially outward of first friction shaft 124 relative to side plate 132 relative to friction plate 134A (fixed friction plate), becomes a rotating friction plate that rotates as first friction shaft 124 rotates.

[0187] The urging portion 136 is provided between one axial end of the first friction shaft 124 and the side plate 132 , and includes a coil spring unit 140 , a pair of buffer plates 142 , and a nut 144 provided at one axial end of the first friction shaft 124 .

[0188] The coil spring unit 140 is composed of a plurality of coil springs 140A. The coil spring 140A is a disk-shaped spring with one surface being convex and the other surface being concave. The plurality of coil springs 140A are stacked and arranged in the axial direction of the first friction shaft 124 .

[0189] Furthermore, buffer plates 142 are disposed axially outside the first friction shaft 124 of the coil spring unit 140. One buffer plate 142 is disposed between the coil spring unit 140 and the friction plate 134B, while the other buffer plate 142 is disposed between the coil spring unit 140 and the nut 144.

[0190] The buffer plate 142 and the disc spring 140A are each formed with an axial hole (not shown). By inserting the first friction shaft 124 into the axial hole, the buffer plate 142 and the disc spring 140A are attached so as to be movable in the axial direction of the first friction shaft 124 .

[0191] When the nut 144 is tightened with the end surface of the coil spring unit 140 in contact with one of the buffer plates 142, the coil spring unit 140 moves in a direction pressing the one of the buffer plates 142. When the coil spring unit 140 moves, a pressing force is applied to each set of friction plates 134A, 134B via the buffer plates 142.

[0192] When the nut 144 is further tightened until the coil spring unit 140 reaches its limit of movement, the coil spring 140A elastically deforms and the coil spring unit 140 contracts in the axial direction of the first friction shaft 124. The coil spring unit 140 applies force in a direction pressing the friction surfaces of the friction plates 134A and 134B against each other due to its elasticity.

[0193] Thus, the friction surfaces of the friction plates 134A and 134B come into contact with each other through the action of the force applying portion 136, and vertical resistance is generated on the friction surfaces. Therefore, when the first friction shaft 124 attempts to rotate, a friction force in the opposite direction of the rotation of the first friction shaft 124 acts on the friction surfaces of the friction plates 134A and 134B.

[0194] The first electromagnetic clutch 128 is attached to the other axial end of the first friction shaft 124. The first electromagnetic clutch 128 includes a housing 148 housing an electromagnet (not shown) and a shaft-fixing portion 150 fixed to the first friction shaft 124. The housing 148 and the shaft-fixing portion 150 are spaced apart from each other. Furthermore, an urging member (not shown) is provided between the housing 148 and the shaft-fixing portion 150 to urge the housing 148 and the shaft-fixing portion 150 away from each other.

[0195] The housing 148 of the first electromagnetic clutch 128 is fixed to the second gear 122. Shaft holes 122A and 148A, through which the first friction shaft 124 is inserted, are formed in the housing 148 and the second gear 122, respectively. Furthermore, a gap is formed between the outer circumference of the first friction shaft 124 and the inner circumference of the shaft holes 122A and 148A. In other words, the housing 148 and the second gear 122 are not connected to the first friction shaft 124.

[0196] The first electromagnetic clutch 128 switches between connecting and disconnecting the second gear 122 and the first friction shaft 124. This in turn switches between connecting and disconnecting the rotating shaft 74 of the first locking mechanism 64 and the first friction shaft 124. Specifically, when power is supplied to the first electromagnetic clutch 128, a magnetic force is generated in the electromagnet housed in the housing 148, attracting the shaft-fixing portion 150 toward the electromagnet against the force of a biasing member (not shown). This creates a tight connection between the housing 148 and the shaft-fixing portion 150.

[0197] When the rotating shaft 74 rotates while the housing 148 is coupled to the shaft fixing portion 150 (corresponding to the first state), the first gear 120, the second gear 122, and the housing 148 of the first electromagnetic clutch 128 rotate along with the rotation of the rotating shaft 74. Furthermore, the shaft fixing portion 150 of the first electromagnetic clutch 128 coupled to the housing 148 and the first friction shaft 124 to which the shaft fixing portion 150 is fixed also rotate along with the rotation of the rotating shaft 74.

[0198] As described above, a friction force in the opposite direction to the rotation direction acts on the first friction shaft 124. Therefore, by rotating the first friction shaft 124 along with the rotation of the rotation shaft 74, a friction force in the opposite direction to the rotation direction acts on the rotation shaft 74.

[0199] A timing pulley 68 is fixed to the rotating shaft 74, and a timing belt 66 fixed to both ends of the arm 12 is wound around the timing pulley 68. Therefore, a friction force in the opposite direction of rotation acts on the rotating shaft 74, and when the arm 12 orbitally rotates, a friction force in the opposite direction of rotation of the arm 12 acts on the arm 12.

[0200] On the other hand, when the first electromagnetic clutch 128 is not energized, the housing 148 fixed to the second gear 122 and the shaft fixing portion 150 fixed to the first friction shaft 124 are separated by a force applied by a biasing member (not shown). Consequently, the housing 148 and the shaft fixing portion 150 are not connected, and the second gear 122 and the first friction shaft 124 are not connected.

[0201] When the housing 148 and the shaft fixing portion 150 are not connected (equivalent to the second state), if the rotating shaft 74 rotates, the first gear 120, the second gear 122, and the housing 148 of the first electromagnetic clutch 128 rotate along with the rotation of the rotating shaft 74. However, the shaft fixing portion 150 of the first electromagnetic clutch 128 and the first friction shaft 124 do not rotate. Therefore, the friction force acting on the first friction shaft 124 during the rotation of the rotating shaft 74 is not exerted, and the friction force acting on the arm 12 during the orbital rotation of the arm 12 is reduced compared to when the first electromagnetic clutch 128 is energized.

[0202] (Structure of the Second Friction Mechanism)

[0203] And, as Figure 14 and Figure 15 As shown in FIG. 1 , the main body 16 of the radiographic apparatus 100 of this embodiment is provided with a second locking mechanism 76 and a second friction mechanism 152 as a friction mechanism. The second locking mechanism 76 has the same structure as that of the first embodiment.

[0204] That is, the second locking mechanism 76 includes a housing 78 and a rotating shaft 80. One end of the rotating shaft 80 is fixed to the arm 12 (see FIG. Figure 16 ) on the other end of the support shaft 24. In this embodiment, a third gear 154 is fixed to the outer peripheral surface of the support shaft 24 so as to be coaxially rotatable, and a fourth gear 156 is meshed with the third gear 154.

[0205] The second friction mechanism 152 includes a second friction shaft 158 , a friction force generating portion 160 attached to the second friction shaft 158 and generating friction force, and a second electromagnetic clutch 162 that switches between connection and disconnection between the support shaft 24 and the second friction shaft 158 .

[0206] The second friction shaft 158 is supported by a frame 164 of the main body 16 via a bearing (not shown). A friction force generator 160 is attached to one axial end of the second friction shaft 158. In this embodiment, the friction force generator 160 is formed of, for example, a rotor damper.

[0207] Specifically, the friction force generating unit 160 includes a rotor (not shown) fixed to one axial end of the second friction shaft 158 , a housing 160A accommodating the rotor, and a viscous material (not shown) such as oil filled between the rotor and the housing 160A.

[0208] When second friction shaft 158 rotates, the rotor fixed to second friction shaft 158 rotates within housing 160A. At this time, a friction force in the opposite direction of rotation acts on the outer peripheral surface of the rotor due to the viscous resistance of the viscous material filled within housing 160A. In other words, a friction force in the opposite direction of rotation acts on second friction shaft 158.

[0209] A second electromagnetic clutch 162 is mounted on the other axial end of the second friction shaft 158. The second electromagnetic clutch 162 has the same structure as the first electromagnetic clutch 128 and includes a housing 166 fixed to the fourth gear 156 and a shaft fixing portion 168 fixed to the second friction shaft 158.

[0210] When the second electromagnetic clutch 162 is energized, the housing 166 is connected to the shaft fixing portion 168 (equivalent to the first state), so that the friction force acting on the second friction shaft 158 in the opposite direction of rotation acts on the support shaft 24 via the fourth gear 156 and the third gear 154. Figure 16 )When the shaft rotates, a friction force in the opposite direction to the rotation of the arm 12 acts on the arm 12.

[0211] On the other hand, if the power to the second electromagnetic clutch 162 is cut off, the housing 166 and the shaft fixing portion 168 are not connected (equivalent to the second state), and the friction force acting on the second friction shaft 158 does not act on the support shaft 24. Therefore, compared with the case where the power to the second electromagnetic clutch 162 is turned on, the arm 12 (refer to Figure 16 ) As the shaft rotates, the friction force acting on the arm 12 decreases.

[0212] (Structure of the control unit)

[0213] like Figure 16 As shown, similarly to the first embodiment, the control unit 170 of the radiation imaging device 100 of this embodiment controls the energization of the solenoid 56. Thus, the control unit 170 switches between a state in which the accommodating portion 104 is allowed to be attached to and detached from the arm 12 and a state in which the accommodating portion 104 is restricted from being attached to and detached from the arm 12.

[0214] Furthermore, similarly to the first embodiment, the control unit 170 determines whether the housing portion 104 is detached from the arm 12 based on the detection signal from the optical sensor 60 provided on the base 44 of the arm 12. In addition, in this embodiment, the control unit 170 determines whether the housing portion 104 is detached from the arm 12 based on the detection signal from the housing recess 110 (refer to Figure 11B ) to determine whether the detector 102 is removed from the accommodating portion 104 based on the detection signal of the optical sensor 112 on the accommodating portion 104.

[0215] Furthermore, similarly to the first embodiment, the control unit 170 controls the first locking mechanism 64 to switch the locked state of the orbital rotation of the arm 12 , and controls the second locking mechanism 76 to switch the locked state of the axial rotation of the arm 12 .

[0216] Furthermore, the control unit 170 controls the first electromagnetic clutch 128. That is, the control unit 170 transmits a drive signal to the first electromagnetic clutch 128 to energize the first electromagnetic clutch 128. Figure 13 The illustrated rotating shaft 74 is connected to the first friction shaft 124 , and a friction force in the opposite direction to the rotation direction acts on the arm 12 .

[0217] On the other hand, the control unit 170 turns off the power to the first electromagnetic clutch 128. Figure 13 The rotating shaft 74 shown is not connected to the first friction shaft 124. Therefore, the friction force acting on the arm 12 is reduced compared to when the first electromagnetic clutch 128 is energized.

[0218] Similarly, the control unit 170 controls the second electromagnetic clutch 162. That is, the control unit 170 transmits a drive signal to the second electromagnetic clutch 162 to energize the second electromagnetic clutch 162. Figure 15 The support shaft 24 shown is connected to the second friction shaft 158 , and a friction force in the opposite direction to the rotation direction acts on the arm 12 .

[0219] On the other hand, the control unit 170 turns off the power to the second electromagnetic clutch 162. Figure 15The support shaft 24 shown is not connected to the second friction shaft 158. Therefore, the friction force acting on the arm 12 is reduced compared to when the second electromagnetic clutch 162 is energized.

[0220] (Control Method of Radiographic Imaging Device)

[0221] Next, use Figure 17 A control method of the radiation imaging device 100 according to this embodiment will be described using the flowchart of FIG.

[0222] First, in step S600, when the power is turned on by operating a power switch (not shown) ("YES" in step S600), the control unit 170 begins controlling the radiographic imaging apparatus 100. Once control by the control unit 170 begins, input of imaging conditions and the like can be received through the operation panel 30. Furthermore, the first locking mechanism 64 and the second locking mechanism 76 employ the same non-excitation-operated electromagnetic brakes as in the first embodiment. Therefore, in this example, when the radiographic imaging apparatus 100 is activated, the rotation of the arm 12 is locked.

[0223] In step S602, the control unit 170 determines whether a lock release operation has been performed to release the rotation lock of the arm 12. If no lock release command has been issued in step S602 ("No" in step S602), the process proceeds to step S604, where the rotation lock state of the arm 12 is maintained. In other words, release of the rotation lock of the arm 12 is prohibited. The process then proceeds to step S620.

[0224] In step S602 , when there is a lock release command (“Yes” in step S602 ), the control unit 170 determines whether the housing unit 104 is attached to the arm 12 (step S606 ).

[0225] If, in step S606, the control unit 170 determines that the housing portion 104 is not attached to the arm 12 ("No" in step S606), the process proceeds to step S604 and maintains the rotation lock state of the arm 12. In other words, releasing the rotation lock of the arm 12 is prohibited. The process then proceeds to step S620.

[0226] In step S606 , when the control unit 170 determines that the housing unit 104 is attached to the arm 12 (YES in step S606 ), the control unit 170 determines whether the detector 102 is attached to the housing unit 104 (step S608 ).

[0227] If, in step S608, the control unit 170 determines that the detector 102 is not mounted on the housing 104 ("No" in step S608), the control unit 170 sets the first friction mechanism 114 and the second friction mechanism 152 to the first state (step S610). Specifically, the control unit 170 energizes the first electromagnetic clutch 128 and the second electromagnetic clutch 162 to couple the housings 148 and 166 to the shaft fixing portions 150 and 168. The control unit 170 then energizes the first locking mechanism 64 and the second locking mechanism 76 to release the rotation lock on the arm 12 (step S614).

[0228] If, in step S608, the control unit 170 determines that the detector 102 is mounted on the housing 104 ("Yes" in step S608), the control unit 170 sets the first friction mechanism 114 and the second friction mechanism 152 to the second state (step S612). Specifically, the control unit 170 de-energizes the first electromagnetic clutch 128 and the second electromagnetic clutch 162, thereby disconnecting the housings 148 and 166 from the shaft fixing portions 150 and 168. The control unit 170 then energizes the first locking mechanism 64 and the second locking mechanism 76 to release the rotation lock on the arm 12 (step S614).

[0229] After releasing the rotation lock of the arm 12 in step S614, the control unit 170 waits until a locking operation is performed to lock the rotation of the arm 12 (step S616). If a lock command is issued ("Yes" in step S616), the control unit 170 locks the rotation of the arm 12 by shutting off power to the first locking mechanism 64 and the second locking mechanism 76 (step S618).

[0230] In step S620, the control unit 170 determines whether the power of the radiographic apparatus 100 has been turned off by the operator operating a power switch (not shown). If the power of the radiographic apparatus 100 has not been turned off ("No" in step S620), the process returns to step S602. On the other hand, if the power of the radiographic apparatus 100 has been turned off ("Yes" in step S620), the control unit 170 terminates control of the radiographic apparatus 100.

[0231] In addition, although Figure 17 Although not shown in the flowchart, in step S614, the power supply to the radiation imaging device 100 may be turned off while the rotation lock of the arm 12 is released. In this case, even if a lock command is not issued via the operation panel 30, the power supply to the first locking mechanism 64 and the second locking mechanism 76 is turned off by turning off the power supply to the radiation imaging device 100, thereby locking the rotation of the arm 12.

[0232] (Effect)

[0233] In the radiation imaging device 100 of this embodiment, the image receiving unit 106 is composed of the detector 102 detachably housed in the housing 104 and the housing 104 detachably held on the arm 12. Furthermore, the radiation imaging device 100 is provided with a photosensor 60 for detecting whether the housing 104 has been removed from the arm 12, and a photosensor 112 for detecting whether the detector 102 has been removed from the housing 104.

[0234] Furthermore, in this embodiment, when the housing portion 104 is removed from the arm 12, that is, when both the housing portion 104 and the detector 102 constituting the image receiving portion 106 are removed from the arm 12, the control unit 170 controls so as to prohibit the release of the rotation lock of the arm 12 even when the lock release operation is performed. Therefore, it is possible to suppress unintentional rotation of the arm 12 when the housing portion 104 of the image receiving portion 106 is removed without using a complex mechanism such as a weight balance adjustment mechanism used in the prior art.

[0235] Furthermore, the radiographic imaging device 100 of this embodiment includes a first friction mechanism 114 and a second friction mechanism 152. The first friction mechanism 114 and the second friction mechanism 152 include a first electromagnetic clutch 128 and a second electromagnetic clutch 162, respectively. This allows the radiographic imaging device 100 to switch between a first state in which frictional force acts on the arm 12 and a second state in which the frictional force acting on the arm 12 is reduced compared to the first state.

[0236] Generally, the change in weight balance of the arm 12 is smaller when the housing portion 104 is attached to the arm 12 and the detector 102 is detached from the housing portion 104 than when both the housing portion 104 and the detector 102 are detached from the arm 12 .

[0237] In this embodiment, the optical sensor 60, which is an example of a first attachment / detachment detection unit, detects that the housing portion 104 is attached to the arm 12, and the optical sensor 112, which is an example of a second attachment / detachment detection unit, detects that the detector 102 is detached from the housing portion 104. In this state, if a lock release operation is performed, the control unit 170 controls the first locking mechanism 64 and the second locking mechanism 76, which are examples of locking mechanisms, to release the lock, and sets the first friction mechanism 114 and the second friction mechanism 152, which are examples of friction mechanisms, to the first state.

[0238] Thus, the rotation of the arm 12 is permitted, and the friction force can be used to suppress unintentional rotation of the arm 12. The state in which only the detector 102 is removed from the arm 12 is a state in which the weight balance of the arm 12 changes little. In this case, even if the rotation of the arm 12 is not completely prohibited by the locking mechanism, the friction force can be used to suppress unintentional rotation of the arm 12. Even if a load due to the friction force is generated, the rotation of the arm 12 is permitted, so the ease of use is improved compared to the case in which the rotation of the arm 12 is completely prohibited.

[0239] On the other hand, if a lock release operation is performed while the optical sensor 60 detects that the housing 104 is attached to the arm 12 and the optical sensor 112 detects that the detector 102 is attached to the housing 104, the control unit 170 controls the first locking mechanism 64 and the second locking mechanism 76 to be released, while also setting the first friction mechanism 114 and the second friction mechanism 152 to a second state in which the friction force is reduced compared to the first state. This facilitates axial or orbital rotation of the arm 12. Since both the housing 104 and the detector 102 are attached to the arm 12, the weight of the arm 12 is balanced. This weight balance prevents unintended rotation of the arm 12, even if rotation of the arm 12 is permitted.

[0240] In the radiographic imaging device 100 of this embodiment, two locking mechanisms for the arm 12 are provided: a first locking mechanism 64 for locking the orbital rotation of the arm 12, and a second locking mechanism 76 for locking the axial rotation of the arm 12. Furthermore, two friction mechanisms are provided: a first friction mechanism 114 for responsiveness to the orbital rotation of the arm 12, and a second friction mechanism 152 for responsiveness to the axial rotation of the arm 12. The control unit 170 controls the two locking mechanisms, prohibiting their release, and switching between their first and second states, depending on the attachment and detachment status of the housing 104 and detector 102 that constitute the image receiving unit 106.

[0241] As shown in this embodiment, it is preferable to control both the two locking mechanisms and the two friction mechanisms. However, it is not necessary to control all of them. For example, the control to prohibit unlocking only requires at least one of the two first locking mechanisms 64 and the second locking mechanism 76. Furthermore, the control to switch the friction mechanisms between the first and second states only requires at least one of the two first friction mechanisms 114 and the second friction mechanism 152.

[0242] <Third embodiment>

[0243] Next, use Figure 1819 , a radiographic imaging device 200 according to a third embodiment of the present invention will be described. Note that the same configurations as those in the second embodiment will be omitted from illustration and description, and the description will focus on the differences.

[0244] In the radiographic apparatus 100 of the second embodiment, the second locking mechanism 76 and the second friction mechanism 152 are provided on the main body 16 . In contrast, in the radiographic apparatus 200 of this embodiment, a rotation angle limiting mechanism 202 is provided on the main body 16 instead of the second friction mechanism 152 .

[0245] The rotation angle limiting mechanism 202 can switch the arm 12 (refer to Figure 2A ) The range of the angular rotation of the shaft relative to the bearing portion 23 is limited to a second range narrower than the first range and a restriction-released state in which the restriction on the rotation angle is released. In the present embodiment, the first range is the range of the angular rotation of the shaft about the axis N of the arm 12 when not restricted by the rotation angle restriction mechanism 202, and is at least 180°.

[0246] Specifically, the rotation angle limiting mechanism 202 includes an abutment member 204 coaxially rotatably fixed to the outer peripheral surface of the support shaft 24 and a cylindrical lock pin 206 extending parallel to the support shaft 24 , that is, extending in the front-rear direction (X direction) of the radiation imaging device 200 .

[0247] A pair of protrusions 208 extending radially outward from the support shaft 24 are provided on the outer peripheral surface of the contact member 204. The pair of protrusions 208 are arranged at a predetermined interval in the circumferential direction of the support shaft 24. The angle θ formed by the pair of protrusions 208 and the central axis of the support shaft 24 (refer to Figure 19B ) becomes the range of the rotation angle of the arm 12 restricted by the rotation angle restriction mechanism 202 (ie, the second range).

[0248] The lock pin 206 is rotatably supported by the frame 164 of the main body 16 via a bearing portion (not shown). In addition, a drive mechanism (not shown) for rotating the lock pin 206 is connected to one axial end of the lock pin 206.

[0249] The lock pin 206 is disposed vertically (in the Z direction) above the support shaft 24. The lock pin 206 is positioned between the pair of protrusions 208 so as to abut against the distal ends of the protrusions 208 when the support shaft 24 rotates about the axis N. Furthermore, a semicircular notch 210 is formed on the outer circumference of the lock pin 206 at a position abutting against the distal ends of the protrusions 208.

[0250] like Figure 19A and Figure 19BAs shown, the locking pin 206 is driven to rotate around the axis by a driving mechanism not shown, thereby being able to switch between a restriction release state in which the notch 210 is located on the lower side, i.e., the side opposite to the protrusion 208, and a restriction state in which the notch 210 is located on the upper side, i.e., the side opposite to the side opposite to the protrusion 208.

[0251] Specifically, if Figure 19A As shown, when the lock pin 206 is in the restriction release state, if the support shaft 24 is rotated around the axis N, the protrusion 208 passes through the notch 210 of the lock pin 206 and does not abut against the lock pin 206. Therefore, the rotation of the support shaft 24 is not restricted, and the arm 12 (refer to Figure 2A ) can rotate the axis within the first range.

[0252] On the other hand, Figure 19B As shown, when the lock pin 206 is in the restricted state, if the support shaft 24 is rotated about the axis N, the protrusion 208 contacts the outer peripheral surface of the lock pin 206. Therefore, the support shaft 24 can only rotate between the angle at which one protrusion 208 contacts the lock pin 206 and the angle at which the other protrusion 208 contacts the lock pin 206. That is, the rotation of the support shaft 24 is restricted by the lock pin 206, and the arm 12 (refer to FIG. Figure 2A ) can only rotate within the second range (angle θ).

[0253] Although not shown in the figure, the control unit of this embodiment is similar to the control unit 170 of the second embodiment (see Figure 16 ) is almost the same, except that, first, a drive signal is sent to a drive mechanism not shown in the figure to rotate the lock pin 206, and the restriction release state and the restriction state of the lock pin 206 are switched.

[0254] The control flow of the control unit of this embodiment is executed using the same steps as the control flow of the control unit 170 of the second embodiment. In the control flow of the second embodiment, if it is determined in step S608 that the detector 102 is not mounted on the housing 104 ("No" in step S608), the control unit 170 sets the first friction mechanism 114 and the second friction mechanism 152 to the first state (step S610).

[0255] However, in this embodiment, instead of this, in step S608, when the control unit 170 determines that the detector 102 is not mounted on the housing portion 104 ("No" in step S608), the control unit puts the rotation angle limiting mechanism 202 into a restricted state in step S610.

[0256] Furthermore, in the control process of the second embodiment, in step S608, when it is determined that the detector 102 is installed on the accommodating portion 104 ("Yes" in step S608), the control unit 170 causes the first friction mechanism 114 and the second friction mechanism 152 to be in the second state (step S612).

[0257] However, in this embodiment, instead of this, in step S608, when the control unit 170 determines that the detector 102 is mounted on the housing portion 104 ("Yes" in step S608), the control unit puts the rotation angle limiting mechanism 202 into the restriction release state in step S612.

[0258] (Effect)

[0259] The radiographic imaging device 200 of this embodiment includes a rotation angle limiting mechanism 202. The rotation angle limiting mechanism 202 is rotationally driven by a drive mechanism (not shown). The rotation angle limiting mechanism 202 can thereby switch between a limiting state in which the range of the rotation angle of the arm 12 is limited to a second range narrower than the first range, and a restriction-free state in which the rotation angle restriction is released.

[0260] As described in the second embodiment, generally, the weight balance of the arm 12 changes less when the housing portion 104 is attached to the arm 12 and the detector 102 is detached from the housing portion 104 than when both the housing portion 104 and the detector 102 are detached from the arm 12 .

[0261] In this embodiment, when the optical sensor 60, an example of a first attachment / detachment detection unit, detects that the housing portion 104 is attached to the arm 12 and the optical sensor 112, an example of a second attachment / detachment detection unit, detects that the detector 102 is removed from the housing portion 104, and a lock release operation is performed, the control unit 170 controls the locking mechanism (the first locking mechanism 64 and the second locking mechanism 76) to release the lock and to place the rotation angle limiting mechanism 202 in a restricted state. The state in which only the detector 102 is removed from the arm 12 is a state in which the weight balance of the arm 12 is minimally altered. In this case, by allowing the arm 12 to rotate within a relatively narrow angle range, inadvertent large rotation of the arm 12 can be suppressed, and ease of use can be ensured.

[0262] On the other hand, when the unlocking operation is performed in a state where the optical sensor 60 detects that the accommodating portion 104 is installed on the arm 12 and the optical sensor 112 detects that the detector 102 is installed on the accommodating portion 104, the control unit 170 performs the following control, i.e., allows the unlocking based on the first locking mechanism 64 and the second locking mechanism 76, and puts the rotation angle limiting mechanism 202 into a restriction release state.

[0263] Thus, when the rotation angle restriction is released (the first range), arm 12 can be axially rotated or orbitally rotated. Since both housing 104 and detector 102 are attached to arm 12, the weight of arm 12 is balanced. This weight balance prevents arm 12 from unintentionally rotating significantly even when the rotation angle restriction is released.

[0264] <Other Implementation Methods>

[0265] While an example of an embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be implemented in various forms without departing from the gist of the present invention. Furthermore, the structures of the above embodiments can be appropriately combined.

[0266] For example, in the third embodiment, the rotation angle limiting mechanism 202 is provided in place of the second friction mechanism 152 of the second embodiment. However, the rotation angle limiting mechanism 202 may be provided in place of the first friction mechanism 114 of the second embodiment. In this case, the rotation angle limiting mechanism 202 can limit the range of the angle of orbital rotation of the arm 12.

[0267] Furthermore, a configuration may be adopted in which the rotation angle limiting mechanism 202 of the third embodiment is provided in addition to the first friction mechanism 114 or the second friction mechanism 152 of the second embodiment. In this case, the first friction mechanism 114 or the second friction mechanism 152 can apply a friction force in the direction opposite to the rotation direction to the arm 12, and the rotation angle limiting mechanism 202 can limit the range of the rotation angle of the arm 12.

[0268] Furthermore, in the first and second embodiments, the orbital rotation of the arm 12 is locked by the first locking mechanism 64, and the axial rotation of the arm 12 is locked by the second locking mechanism 76. However, the arm 12 may be configured so that at least one of the orbital rotation and the axial rotation is locked.

[0269] Furthermore, in the second embodiment, two friction mechanisms, namely the first friction mechanism 114 and the second friction mechanism 152 , are provided. However, the friction mechanism may be only one of the first friction mechanism 114 and the second friction mechanism 152 .

[0270] Furthermore, in the first to third embodiments, a configuration may be adopted in which it is determined whether the irradiation section 18 is continuously irradiating radiation, that is, whether animation photography is being performed, and the release of the rotation lock of the arm 12 is prohibited while the irradiation section 18 is continuously irradiating radiation.

[0271] Specifically, if Figure 20 As shown, for example, in the control flow of the first embodiment, between steps S506 and S508, a step S516 for determining whether animation photography is being performed may be added. Specifically, if it is determined that the image receiving unit 20 (i.e., the detector) is attached to the arm 12 ("Yes" in step S506), the control unit 28 determines whether animation photography is being performed (step S516).

[0272] If the video is not being recorded ("No" in step S516), the rotation lock of the arm 12 is released (step S508). If the video is being recorded ("Yes" in step S516), the rotation lock of the arm is maintained (step S504). In other words, the release of the rotation lock of the arm 12 is prohibited.

[0273] According to the above configuration, even when the image receiving unit 20 is attached to the arm 12, the arm 12 rotation lock is prohibited from being released even if the lock release operation is performed during the animation imaging period in which radiation is continuously irradiated from the irradiation unit 18. Therefore, it is possible to prevent the arm 12 from being inadvertently rotated and causing unnecessary radiation to be irradiated to a part other than the target imaging part.

[0274] Furthermore, in the first embodiment, the image receiving unit 20 (i.e., the detector) is fitted into the fitting recess 48 and the fitting protrusion 46 provided at the other end of the arm 12, so that the image receiving unit 20 can be detachably mounted on the arm 12. However, the method of attaching and detaching the image receiving unit 20 to the arm 12 is not limited to the structure of the first embodiment.

[0275] For example, Figure 21 As shown, a configuration may be adopted in which a mounting portion 218 having a mounting recess 218A is fixed to the other end of the arm 12, and an image receiving unit 220 (i.e., a detector) is detachably accommodated in the mounting recess 218A of the mounting portion 218. In this case, as in the first embodiment, when the image receiving unit 220 is removed from the mounting portion 218, the rotation of the arm 12 is locked, and when the image receiving unit 220 is attached to the mounting portion 218, the rotation lock of the arm 12 is released.

[0276] According to the above structure, the image receiving unit 220 can be mounted on the arm 12 by accommodating the image receiving unit 220 in the mounting recess 218A of the mounting portion 218. Therefore, there is no need to form a fitting recess or the like on the lower surface of the image receiving unit 220 as in the first embodiment, and, for example, an existing image receiving unit 220 can be easily used.

[0277] Furthermore, in the second embodiment, the "second state" of the first friction mechanism 114 and the second friction mechanism 152 is a state in which the friction force of the first friction shaft 124 and the second friction shaft 158 does not act on the arm 12 (a state in which the friction force that acts is 0). However, the "second state" only needs to reduce the friction force acting on the arm 12 at least compared to the "first state", and the friction force is not limited to the state of 0. For example, by adjusting the friction force based on Figure 13 The tightening force of the nut 144 shown is such that the friction force acting on the first friction shaft 124 is reduced compared to the “first state”, and the first friction mechanism 114 can be placed in the “second state”.

[0278] Furthermore, in the third embodiment, the spacing (angle θ) between the pair of protrusions 208 is fixed, and the range of the rotation angle of the arm 12 that can be limited by the rotation angle limiting mechanism 202 is only the second range. However, the range of the rotation angle of the arm 12 that can be limited can be changed by changing the protrusion position of the protrusion 208 on the outer peripheral surface of the contact member 204. In this case, for example, the range of the rotation of the arm 12 can be changed by the weight of the image receiving unit 106 attached to or detached from the arm 12 (the magnitude of the change in weight balance).

[0279] Furthermore, in the above-described embodiments, an arm 12 capable of both orbital and axial rotation (C-arm) has been described as an example, but an arm capable of only axial rotation (e.g., a U-arm having a U-shaped side profile) may also be used. Similar to the C-arm, the U-arm can hold the irradiation unit 18 and the image receiving units 20, 106, 120, etc. in a position where they face each other.

[0280] Furthermore, although X-rays have been described as an example of radiation, the radiation is not limited to X-rays and may be gamma rays or the like.

[0281] In each of the above-described embodiments, various processors described below can be used as the hardware configuration of the processing units (Processing Units) that execute various processes, such as the control units 28 and 170. As described above, these various processors include general-purpose processors (CPUs) that execute software to function as various processing units, as well as processors whose circuit configuration can be modified after manufacturing, such as FPGAs (Field Programmable Gate Arrays), programmable logic devices (PLDs), and application-specific integrated circuits (ASICs), which are processors with circuit configurations specifically designed to execute specific processes, such as dedicated circuits.

[0282] A single processing unit may be composed of one of these various processors, or a combination of two or more processors of the same or different types (e.g., a combination of multiple FPGAs and / or a combination of a CPU and an FPGA). Furthermore, a single processor may constitute multiple processing units.

[0283] The first method is to use a single processor to form multiple processing units, where a combination of one or more CPUs and software forms a single processor, and the processor functions as multiple processing units. The second method is to use a processor that implements the functions of the entire system including multiple processing units on a single IC (Integrated Circuit), as exemplified by a system-on-chip (SoC). In this manner, various processing units are formed using one or more of the aforementioned processors as a hardware configuration.

[0284] Furthermore, as the hardware configuration of these various processors, more specifically, a circuit (circuitry) combining circuit elements such as semiconductor elements can be used.

[0285] The disclosures of Japanese Patent Application No. 2019-199332 filed on October 31, 2019, and Japanese Patent Application No. 2019-180016 filed on September 30, 2019, are incorporated herein by reference in their entirety. All documents, Japanese patent applications, and technical standards described in this specification are incorporated herein by reference in the same manner as if each document, Japanese patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. A radiographic imaging device comprising: Irradiation part, irradiating radiation; an arm for holding the irradiation unit and the image receiving unit in a posture in which the irradiation unit and the image receiving unit that receive the radiation irradiated from the irradiation unit and transmitted through the subject are opposed to each other, and for detachably holding the image receiving unit; a support portion that rotatably supports the arm; a locking mechanism for locking the rotation of the arm relative to the support portion; a first attachment and detachment detection unit configured to detect whether the image receiving unit is detached from the arm; and The control unit, in a state where the first attachment and detachment detection unit detects that the image receiving unit is detached from the arm, performs control so as to prohibit the release of the lock even if a lock release operation for releasing the lock based on the rotation of the lock mechanism is performed, The image receiving unit includes: a detector that detects a radiographic image of the subject by receiving the radiation irradiated from the irradiating unit and transmitted through the subject; and a housing that detachably houses the detector and is detachably held on the arm. The radiation imaging device further comprises: a friction mechanism capable of switching between a first state in which a friction force in a direction opposite to the direction of rotation of the arm acts on the arm and a second state in which the friction force acting on the arm is smaller than in the first state; and The second attachment and detachment detection unit detects whether the detector is detached from the housing unit. The first attachment and detachment detection unit detects whether the storage unit is detached from the arm. When the lock release operation is performed in a state where the first attachment and detachment detection unit detects that the housing portion is attached to the arm and the second attachment and detachment detection unit detects that the detector is detached from the housing portion, The control unit performs control to allow the lock to be released by the lock mechanism and to place the friction mechanism in the first state.

2. The radiation imaging device according to claim 1, wherein When the lock release operation is performed in a state where the first attachment and detachment detection unit detects that the housing portion is mounted on the arm and the second attachment and detachment detection unit detects that the detector is mounted on the housing portion, The control unit performs control to allow the lock to be released by the lock mechanism and to place the friction mechanism in the second state.

3. A radiographic imaging device comprising: Irradiation part, irradiating radiation; an arm for holding the irradiation unit and the image receiving unit in a posture in which the irradiation unit and the image receiving unit that receive the radiation irradiated from the irradiation unit and transmitted through the subject are opposed to each other, and for detachably holding the image receiving unit; a support portion that rotatably supports the arm; a locking mechanism for locking the rotation of the arm relative to the support portion; a first attachment and detachment detection unit configured to detect whether the image receiving unit is detached from the arm; and The control unit, in a state where the first attachment and detachment detection unit detects that the image receiving unit is detached from the arm, performs control so as to prohibit the release of the lock even if a lock release operation for releasing the lock based on the rotation of the lock mechanism is performed, The image receiving unit includes: a detector that detects a radiographic image of the subject by receiving the radiation irradiated from the irradiating unit and transmitted through the subject; and a housing that detachably houses the detector and is detachably held on the arm. The radiation imaging device further comprises: a rotation angle limiting mechanism capable of switching between a limiting state in which the range of the arm's rotation angle is limited to a second range narrower than the first range and a restriction-released state in which the restriction on the rotation angle is released; and The second attachment and detachment detection unit detects whether the detector is detached from the housing unit. The first attachment and detachment detection unit detects whether the storage unit is detached from the arm. When the lock release operation is performed in a state where the first attachment and detachment detection unit detects that the housing portion is attached to the arm and the second attachment and detachment detection unit detects that the detector is detached from the housing portion, The control unit performs control to allow the lock to be released by the lock mechanism and to place the rotation angle restriction mechanism in the restricted state.

4. The radiation imaging device according to claim 3, wherein When the lock release operation is performed in a state where the first attachment and detachment detection unit detects that the housing portion is mounted on the arm and the second attachment and detachment detection unit detects that the detector is mounted on the housing portion, The control unit performs control to allow the lock to be released by the lock mechanism and to place the rotation angle restriction mechanism in the restriction released state.

5. The radiation imaging device according to any one of claims 1 to 4, wherein The arm is in the shape of an arc when viewed from the side, The support portion includes a rail portion that supports the arm movably along the arc shape. The arm can perform orbital rotation about the center of the arc shape as a rotation center by moving relative to the rail portion.

6. The radiation imaging device according to any one of claims 1 to 4, wherein The support portion includes a bearing portion that supports the other end side of a support shaft whose one end is fixed to the arm. The arm can reverse the positions of the irradiation unit and the image reception unit relative to the subject by rotating about the axis of the support shaft relative to the bearing unit.

7. The radiation imaging device according to any one of claims 1 to 4, wherein Even in a state where the image receiving unit is detected to be mounted on the arm by the first loading and unloading detection unit, the control unit performs the following control while the radiation is continuously irradiated from the irradiation unit, that is, even if a lock release operation for releasing the lock based on the rotation of the locking mechanism is performed, the lock is prohibited from being released.

Images