Radiation imaging device

Abstract

The radiation imaging device comprises: an arm, which can be provided with an irradiation unit at one of the first end and the second end and an image receiving unit is installed at the other end; a support portion, which supports the arm in a manner capable of orbital rotation; a cable, which is arranged from the first end of the arm toward the support portion; a belt, which is arranged from the second end of the arm toward the support portion; a first reel, which winds up the cable; a second reel, which is arranged in a manner capable of independent rotation relative to the first reel and winds up the belt; and a spring, which applies a force to the first reel in a winding direction of the cable and applies a force to the second reel in a winding direction of the belt, and allows a difference between the rotation amount of the first reel and the rotation amount of the second reel.

Description

Technical Field

[0001] The present invention relates to a radiation imaging device. Background Art

[0002] There is known a radiation imaging device having an arm having two ends, a first end and a second end, and an irradiation unit for irradiating radiation can be provided at one end and an image receiving unit for receiving radiation irradiated from the irradiation unit and transmitted through a subject can be installed at the other end (see Japanese Patent Application Laid-Open No. 8-229027). The side shape of the arm is an arc shape, and is called a C-arm or the like.

[0003] The arm can perform orbital rotation so that the irradiation unit and the image receiving unit rotate around the subject in an opposing posture. The arm is supported by a support portion having a track portion that fits into the outer peripheral portion of the circular arc shape of the arm. If the outer peripheral portion of the arm moves along the track portion, the arm performs orbital rotation with the center of the circular arc shape as the rotation center.

[0004] Furthermore, a cable for electrically connecting to the irradiation part and the image receiving part is provided on the arm. The cable is arranged on the outer periphery of the arm and introduced into the support part. For example, in the case where the cable is arranged from the first end of the arm toward the support part, the length of the cable is determined according to the rotation range of the orbital rotation of the arm. The maximum length of the cable from the support part to the first end of the arm is the length to the position where the first end is farthest from the support part. Therefore, if the arm is orbitally rotated in the first direction in which the first end approaches the support part, the cable is loosened by the amount that the first end approaches the support part. If the cable is loose, the loose part hinders the operation, so a countermeasure to suppress the loosening of the cable is required.

[0005] In order to solve this problem, for example, the radiation imaging device (X-ray device) described in Japanese Patent Gazette No. 8-229027 includes: a winding drum for winding a cable (electric wire); a pulley that is configured to rotate integrally with the winding drum on the same axis; and a conductive wire that is wound around the pulley for applying tension to the cable.

[0006] According to the radiation imaging device disclosed in Japanese Patent Application Laid-Open No. 8-229027, when the arm rail is rotated, the pulley is rotated by feeding the wire from the pulley. The rotation of the pulley also rotates the take-up drum, and the cable is wound on the take-up drum. In this way, the pulley and the take-up drum rotate by feeding the wire, so that tension is applied to the cable, and the slack of the cable is suppressed by the application of tension. Summary of the invention

[0007] Technical issues to be solved by the invention

[0008] However, if there is a diameter difference between the diameter of the cable (wire) and the diameter of the conductor, the winding circumference of the winding drum and the pulley changes according to the winding amount. The winding circumference refers to the winding amount of the cable or conductor per unit rotation of the winding drum and the pulley, for example, the length of the cable that can be wound when the winding drum rotates one circle. In the case where the diameter of the cable is thick, if the cable is overlapped and wound into double or triple layers, the diameter of the winding drum becomes thicker, and thus the winding circumference also becomes longer. Furthermore, in the case where there is a diameter difference between the diameter of the cable and the diameter of the conductor, if the winding amount is increased by overlapping winding, the difference between the change in the winding circumference of the cable of the winding drum and the change in the winding circumference of the conductor of the pulley becomes larger.

[0009] When there is a difference between the winding circumference of the cable of the winding drum and the winding circumference of the conductor of the pulley, the following problems occur. For example, as a first case, the following case is considered: when the winding circumference of the cable of the winding drum is longer than the winding circumference of the conductor of the pulley, the arm is orbitally rotated in a direction in which the cable is wound on the winding drum, that is, in a direction in which the first end portion connected to the cable approaches the support portion.

[0010] In the first case, the amount of the wire fed from the pulley, one end of which is fixed to the second end, is determined by the amount of rotation of the orbit of the arm, and the pulley and the winding drum rotate only by the same amount in the same direction according to the fed amount. In this case, the winding circumference of the winding drum is long, so a cable exceeding the amount of wire fed is wound on the winding drum, and a tension greater than necessary is applied to the cable, which exceeds the tension required for winding. Applying a tension greater than necessary to the cable may cause the cable to break, so it is not preferable.

[0011] As a second case, consider the following case: in contrast to the first case, the arm is orbitally rotated in the direction in which the cable is fed out from the take-up drum. In the second case, the rotation amount of the take-up drum and the pulley is determined according to the amount of cable fed out from the take-up drum. The take-up circumference of the pulley is shorter than the take-up circumference of the take-up drum, so the take-up amount of the wire is insufficient relative to the amount of cable fed out. Therefore, in the second case, the wire is slack.

[0012] In this way, due to the difference between the winding circumference of the cable and the winding circumference of the tension member that applies tension to the cable, problems such as unnecessary tension being applied to the cable or slack of the tension member occur.

[0013] Among them, in the X-ray device disclosed in Japanese Patent Laid-Open No. 8-229027, a study was conducted as follows: a tapered cylindrical pulley whose diameter changes along the rotation axis direction is used as a pulley, and a wire guide groove for guiding a wire is formed in a spiral shape on the tapered cylindrical surface of the pulley, so that there is no difference between the winding circumference of the overlappingly wound cable (wire) and the winding circumference of the wire (refer to paragraphs 0022 and 0023 of Japanese Patent Laid-Open No. 8-229027). Fig.12 However, when a conical pulley having a spiral conductor guide groove is manufactured, the processing becomes complicated and the cost is high. Therefore, it is required to solve the problem caused by the difference between the winding circumference of the cable and the winding circumference of the tension member in a simpler way.

[0014] The technology according to the present invention provides a radiation imaging device that can more easily solve the problem caused by the difference between the winding circumference of the cable and the winding circumference of the tension member.

[0015] Means for solving technical problems

[0016] The radiation imaging device according to the first embodiment of the present invention comprises: an arm, wherein an irradiation unit for irradiating radiation can be provided at one of a first end and a second end, and an image receiving unit for receiving radiation irradiated from the irradiation unit and transmitted through a subject is installed at the other end, wherein the side surface of the arm is in an arc shape, and the irradiation unit and the image receiving unit can be rotated in an orbit around the subject in an opposing posture; a support unit having a track unit that fits into the outer peripheral portion of the arc shape of the arm and supports the arm in a manner capable of orbital rotation; a cable, one end of which is electrically connected to at least one of the irradiation unit and the image receiving unit, and the cable is arranged along the outer periphery of the arm from the Jth end of the arm toward the support unit; a tension member for applying tension to the cable when the arm is orbitally rotated in a first direction in which the first end approaches the support unit, wherein one end of the tension member is fixed to the second end of the arm, and the tension member is arranged along the outer periphery of the arm from the second end toward the support unit; The cam is an axial shaft, which rotates in the direction of winding up the cable when the arm is orbitally rotated in the first direction, and rotates in the direction of sending out the cable when the arm is orbitally rotated in the second direction close to the support portion; a second reel, which rotates in the direction of sending out the tension member when the arm is orbitally rotated in the first direction, and rotates in the direction of winding up the tension member when the arm is orbitally rotated in the second direction, wherein the second reel is arranged to be independently rotatable relative to the first reel; and a rotational force transmission component, which transmits a rotational force in the same direction to the other reel when one of the first reel and the second reel is rotated, wherein the rotational force transmission component applies a force to the first reel in the winding direction of the cable, and applies a force to the second reel in the winding direction of the tension member, and when transmitting the rotational force, a difference between the rotation amount of the first reel and the rotation amount of the second reel is allowed within a predetermined range.

[0017] According to the above structure, the cable arranged along the outer circumference of the arm from the first end of the arm is wound on the first reel. And the tension member arranged along the outer circumference of the arm from the second end of the arm is wound on the second reel. Therefore, when the arm rail is rotated, one of the cable and the tension member is wound and the other is fed out.

[0018] The first reel and the second reel can rotate independently of each other, but when one of the reels rotates, the rotational force in the same direction is transmitted to the other reel through the rotational force transmission component. The rotational force transmission component applies force to the first reel in the winding direction of the cable, and applies force to the second reel in the winding direction of the tension component (the side opposite to the winding direction of the cable of the first reel). Moreover, when the rotational force transmission component transmits the rotational force, a difference between the rotation amount of the first reel and the rotation amount of the second reel is allowed to occur within a preset range.

[0019] Therefore, if the arm is rotated along the first direction track, the second end portion is away from the support portion, so the tension member rotates the second reel in the delivery direction. The rotational force is transmitted from the second reel to the first reel through the rotational force transmission member, so that the first reel rotates in the same direction as the second reel. The delivery direction of the second reel is the same as the winding direction of the first reel, so the first reel winds up the cable. As a result, the slack of the cable between the first end portion and the support portion is suppressed.

[0020] The rotation force transmission component applies force to the first reel in the cable winding direction and applies force to the second reel in the winding direction of the tension component. When transmitting the rotation force, the rotation force transmission component allows a difference between the rotation amount of the first reel and the rotation amount of the second reel within a preset range.

[0021] Therefore, even when the winding circumference of the cable onto the first reel and the winding circumference of the tension member onto the second reel vary, the tension member can be fed out and the cable can be wound while adjusting the rotation amounts of the first reel and the second reel by only the difference in the winding circumference according to the difference in the diameter of the cable and the diameter of the tension member. Thus, it is suppressed that a tension greater than necessary or slack is applied to the tension member and the cable due to the difference in the winding circumference.

[0022] In the past, in order to solve this problem, the following research was conducted: by making a conical pulley with a spiral conductor (tension member) guide groove, etc., a complex process was performed to avoid the difference between the winding circumferences. In contrast, according to the technology of the present invention, such a complex process is not required. Therefore, the problem caused by the difference between the winding circumference of the cable and the winding circumference of the tension member can be solved more simply.

[0023] A radiation imaging device according to a second aspect of the present invention is the radiation imaging device according to the first aspect, wherein the first reel and the second reel are coaxially arranged.

[0024] According to the above configuration, the first reel and the second reel are arranged on the same axis, so the configuration becomes simpler and space can be saved compared to a configuration in which the first reel and the second reel are arranged on different axes.

[0025] A radiation imaging device according to a third aspect of the present invention is the radiation imaging device according to the first aspect or the second aspect, wherein the first reel and the second reel are provided in the support portion.

[0026] According to the above structure, the support part is the connecting part between the arm and the main body, and thus functions as a relay part of the cable between the arm and the main body. By providing the first reel here, the wiring of the cable is easy. In addition, the support part is the part that becomes the base point of the arm that rotates in the orbit, so from the viewpoint of suppressing the complexity of the structure, the support part is the best position for introducing the cable and the tension member arranged on the outer periphery of the arm. By providing the first reel and the second reel at this position, the complexity of the structure can be suppressed.

[0027] The radiation imaging device according to the fourth aspect of the present invention is a radiation imaging device according to any one of the first to third aspects, wherein, when the thickness of the cable is thicker than the thickness of the tension member, the first radius of the winding portion of the first reel when the cable is not wound is smaller than the second radius of the winding portion of the second reel when the tension member is not wound.

[0028] According to the above structure, when the thickness of the cable is thicker than the thickness of the tension member, by making the first radius of the winding portion of the first reel smaller than the second radius of the winding portion of the second reel, it is possible to suppress the increase in the difference between the winding circumference of the cable and the winding circumference of the tension member when the cable and the tension member are wound by the first reel and the second reel. In addition, the winding portion refers to the portion on which the cable or the tension member is wound on the first reel and the second reel.

[0029] A radiation imaging device according to a fifth aspect of the present invention is the radiation imaging device according to the fourth aspect, wherein the first radius is smaller than the second radius, and the difference between the first radius and the second radius is equal to the difference between the thickness of the cable and the thickness of the tension member.

[0030] According to the above structure, the difference between the first radius of the first reel and the second radius of the second reel is equal to the difference between the height of the cable and the height of the tension member. Therefore, when the cable and the tension member are wound around the first reel and the second reel by one turn respectively, the winding circumference of the cable and the winding circumference of the tension member become equal.

[0031] In this way, by making the winding circumference of the first reel when the cable is wound one circle equal to the winding circumference of the second reel when the tension member is wound one circle, the maximum value of the difference between the winding circumference of the cable and the winding circumference of the tension member when the cable is wound multiple times can be reduced.

[0032] A radiation imaging device according to a sixth aspect of the present invention is the radiation imaging device according to any one of the first to fifth aspects, wherein the cable includes a first cable for applying a voltage to a radiation tube of the irradiation unit.

[0033] According to the above structure, the voltage applied to the radiation tube is relatively high, so the thickness of the insulating coating of the cable for applying the voltage becomes thicker. Therefore, the diameter of the cable for applying the voltage tends to become thicker. On the other hand, the tension member only needs to be able to apply tension, so the diameter can be made thinner. In this way, in the case where the cable is a cable for applying voltage to the radiation tube, the difference in winding circumference changes according to the winding amount on the first reel, and the difference in winding circumference between the first reel and the second reel also tends to become larger. Therefore, the necessity of adopting the technology of the present invention is high.

[0034] The radiation imaging device involved in the 7th mode of the present invention is the radiation imaging device involved in the 6th mode, wherein the cable includes a first cable and a second cable connected to the image receiving part, and the first cable and the second cable are arranged on the outer periphery of the arm as a bundled cable group between the first reel and the first end, and the cable group is fixed to the first end, and the first cable and the second cable are branched on the side opposite to the first reel with reference to the position where the cable group is fixed, so that one of the first cable and the second cable is connected to one of the irradiation part and the image receiving part arranged at the first end, and the other cable is extended to the second end by being arranged inside the arm, and is connected to the other of the irradiation part and the image receiving part arranged at the second end.

[0035] According to the above structure, the first cable and the second cable are arranged on the outer periphery of the arm as a bundled cable group between the first reel and the first end. The cables arranged on the outer periphery of the arm are concentrated on the first end side of the arm, thereby suppressing the complexity of the electrical wiring compared to the case where the cables are arranged separately on the first end and the second end of the outer periphery of the arm.

[0036] A radiation imaging device according to an eighth aspect of the present invention is the radiation imaging device according to any one of the first to seventh aspects, wherein an irradiation unit is provided at the first end portion.

[0037] According to the above structure, when the radiographic device is used for animation photography (also called fluoroscopy photography, etc.), the irradiation unit is usually arranged below the subject, and the image receiving unit is usually arranged above the subject. Animation photography is often performed during surgery, and it is not preferable to arrange the cable on the arm above the subject. This is because, for example, if the cable is loose above the subject, it may hinder the surgery.

[0038] Therefore, by providing the irradiation portion side, which is often arranged below the subject during video shooting, as the first end portion of the arm, the cable arrangement portion can be arranged below the subject during video shooting on the arm.

[0039] A radiation imaging device according to a ninth aspect of the present invention is the radiation imaging device according to any one of the first to eighth aspects, wherein the other end of the tension member is fixed to the second winding shaft.

[0040] According to the above structure, by fixing the other end of the tension member to the second reel, for example, compared with the structure in which the two ends of the tension member are respectively fixed to one end and the other end of the arm via the second reel, the length of the tension member can be shortened, thereby suppressing the complexity of the structure of the second reel.

[0041] A radiation imaging device according to a tenth aspect of the present invention is the radiation imaging device according to any one of the first to ninth aspects, wherein the tension member is a belt or a wire.

[0042] According to the above configuration, by using a tape or a wire as the tension member, the diameter of the tension member can be reduced, and tension can be applied to the cable by the tension member.

[0043] In the radiation imaging device according to the 11th aspect of the present invention, in the radiation imaging device according to any one of the 1st to 10th aspects, the rotational force transmission component is a spring, which connects the first reel and the second reel and expands and contracts when the first reel and the second reel are rotated in opposite directions.

[0044] According to the above configuration, by using a spring as the rotational force transmission member, the rotational force can be transmitted with a simple configuration, and the first reel and the second reel can be urged in the winding directions of the cable and the tension member, respectively.

[0045] The radiation imaging device according to the 12th aspect of the present invention is the radiation imaging device according to the 11th aspect, wherein one end of the spring is mounted on a first pin provided on a side surface of the first winding shaft, and the other end of the spring is mounted on a second pin provided on a side surface of the second winding shaft.

[0046] According to the above configuration, the spring can be mounted on the first and second reels with a simple structure by providing the first and second pins at both ends of the spring on the side surfaces of the first and second reels, respectively.

[0047] Effects of the Invention

[0048] According to the technology related to the present invention, the problem caused by the difference between the winding circumference of the cable and the winding circumference of the tension member can be solved more simply. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is an overall perspective view showing a radiation imaging device according to an example of an embodiment.

[0050] Figure 2A It is a side view of a radiation imaging device according to an example of an embodiment.

[0051] Figure 2B It means to make Figure 2A 1 is a side view of the radiation imaging device shown in the state where the arm is rotated in the direction of arrow M1.

[0052] Figure 2C It means to make Figure 2A 1 is a side view of the radiation imaging device shown in the state where the arm is rotated in the direction of arrow M2.

[0053] Figure 3A It is a front view of a radiation imaging device according to an example of an embodiment.

[0054] Figure 3B It means to make Figure 3A The illustrated radiation imaging device is a front view of a state in which the arm is rotated in the direction of arrow N1.

[0055] 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 degrees in the direction of arrow N2.

[0056] Figure 4 It is an overall side view showing a cable and a tension member of a radiation imaging device according to an example of an embodiment.

[0057] Figure 5 is along Figure 4 Sectional view taken along line AA.

[0058] Figure 6 It is a partial perspective view showing a first end portion of a radiation imaging device according to an example of an embodiment.

[0059] Figure 7 This is a partial perspective view showing a state in which a cable and a tension member of a radiation imaging device according to an example of an embodiment are wound around a first reel and a second reel.

[0060] Fig. 8A It is an exploded perspective view showing a first spool, a second spool, and a rotational force transmission member of a radiation imaging device according to an example of an embodiment.

[0061] Figure 8B It means assembled Fig. 8A A perspective view showing the state of the first reel, the second reel, and the rotational force transmission member.

[0062] Fig. 9AIt is an explanatory diagram of the difference in circumference between the winding circumference of the first reel and the winding circumference of the second reel, and shows the first radius of the first reel and the diameter of the cable.

[0063] Fig. 9B It is an explanatory diagram of the difference in circumference between the winding circumference of the first reel and the winding circumference of the second reel, and shows the second radius of the second reel and the thickness of the tape.

[0064] Fig.10 It is a cross-sectional view of a first reel and a second reel of a radiation imaging device according to an example of an embodiment.

[0065] Fig.11 It is a side view schematically showing the first reel and the second reel when the arm of the radiation imaging device according to an example of the embodiment is rotated along a first direction orbit.

[0066] Fig.12 It is a side view schematically showing the first reel and the second reel when the arm of the radiation imaging device according to the example of the embodiment is rotated along the second direction orbit.

[0067] Fig.13 It is a side view schematically showing the first reel and the second reel when the arm of the radiation imaging device according to the comparative example is rotated along a first direction orbit.

[0068] Fig.14 It is a side view schematically showing the first reel and the second reel when the arm of the radiation imaging device according to the comparative example is rotated along the second direction orbit. DETAILED DESCRIPTION

[0069] Hereinafter, a radiographic imaging device according to an example of an embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, arrow X indicates the front-rear direction of the radiographic imaging device, arrow Y indicates the width direction of the radiographic imaging device, and arrow Z indicates the vertical direction.

[0070] (Overall Structure of Radiographic Imaging Device)

[0071] Figure 1The radiographic device 10 of the present embodiment shown is a device for capturing radiographic images of a subject H. The radiographic 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 a treatment target portion of the subject H in the form of 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 device 10. Of course, the captured animation data can also be stored in the memory of the radiographic device 10. Furthermore, when performing still image photography, the captured still image can also be displayed on the monitor or stored in the memory of the radiographic device 10.

[0072] like Figure 1 As shown, the radiation imaging device 10 includes an arm 12 (referred to as a C-arm or the like) whose side shape is a C-shape (arc shape), a support portion 14 that supports the arm 12 in an orbital rotation manner, and a main body portion 16 that supports the arm 12 in an axial rotation manner. In addition, in the following, the side of the radiation imaging device 10 where the arm 12 is provided is set as the front of the radiation imaging device 10, and the side where the main body portion 16 is provided is set as the rear of the radiation imaging device 10.

[0073] (Arm structure)

[0074] The arm 12 has two ends, a first end 12A and a second end 12B. The first end 12A of the arm 12 is provided with an irradiation unit 18, and the second end 12B is provided with an image receiving unit 20. The arm 12 can hold the irradiation unit 18 and the image receiving unit 20 in an opposing posture. A space is ensured between the irradiation unit 18 and the image receiving unit 20 so that a subject H and a bed S on which the subject H lies supinely can be inserted. In addition, in the following, in a side view (in Figure 1 When the arm 12 is viewed from the Y direction, 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 support unit 14 side is sometimes referred to as the rear of the arm 12.

[0075] like Figure 2A As shown, the arm 12 is configured to be able to perform orbital rotation around the axis M (axis parallel to the Y axis) relative to the rail portion 22B provided on the support portion 14. In addition, the arm 12 is configured to be able to perform axial rotation around the axis N (axis parallel to the X axis) relative to the bearing portion 23 provided on the main body 16.

[0076] 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 periphery of the arm 12. The fitting portion 22A has an arc shape along the shape of the arm 12. Figure 5As shown, the rail portion 22B is, for example, in a groove shape, and the convex fitting portion 22A fits in. In addition, 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.

[0077] like Figure 2A As shown, the fitting portion 22A formed on the arm 12 slides along the rail portion 22B formed on the support portion 14. Thus, the arm 12 is provided to be able to orbitally rotate relative to the support portion 14 and the main body 16 about the axis M of the arc center of the arm 12 as the rotation center.

[0078] That is, Figure 2B and Figure 2C As shown, the arm 12 is configured to move in the direction of arrow M1 ( 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 arranged to surround the subject H (reference Figure 1 )'s body axis (an axis parallel to the Y axis).

[0079] And, if Figure 2A As shown in FIG. 1 , one end of a support shaft 24 extending in the front-rear direction (X direction) of the radiation imaging device 10 is fixed to the arm 12. The other end of the support shaft 24 is supported by the main body 16 via a bearing 23. The support shaft 24 rotates relative to the bearing 23 about the axis N as the center, as shown in FIG. Figure 3A to Figure 3C As shown, the arm 12 and the support portion 14 are provided so as to be axially rotatable with respect to the main body portion 16 about the axis line N of the support shaft 24 as the rotation center.

[0080] 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 ( Figure 3C Thus, the irradiation unit 18 and the image receiving unit 20 provided at both ends of the arm 12 can be made to be oriented relative to the subject H (reference Figure 1 )'s position in the up-and-down direction (Z-axis direction) is reversed.

[0081] Among them, about Figure 3A The arm 12 is in a posture in which 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 posture of the arm 12 shown, the irradiation unit 18 is arranged 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.

[0082] Compared with the lower tube posture, the outer tube posture can expand the distance between the irradiation unit 18 and the subject H (refer to Figure 1 ) between the two sides. Thus, in the overtube posture, a relatively wide area can be imaged. Therefore, the overtube posture is mainly used when capturing a still image of the subject H. On the other hand, in the undertube posture, the radiation irradiated from the irradiation unit 18 is partially shielded by the bed S and the like. Thus, in the undertube posture, the radiation irradiation on the subject H (reference Figure 1 ) to reduce the radiation dose to the surgeon or operator (not shown) around the subject. Therefore, the tube-down posture is used when capturing a moving picture of the subject H by continuously irradiating radiation.

[0083] (Structure of the main body)

[0084] like Figure 1 As shown, the main body 16 of the radiation imaging device 10 has a plurality of casters 26 mounted on the lower portion thereof, and is configured to be able to travel in, for example, an operating room or a hospital room by being pushed by an operator. That is, the radiation imaging device 10 of this embodiment is configured to be mobile.

[0085] The main body 16 has a control unit 28 for controlling the various parts of the radiation imaging device 10 such as the irradiation unit 18, and a touch panel type operation panel 30. In addition, the main body 16 has various switches (not shown) such as a power switch of the radiation imaging device 10, a power circuit and a battery for supplying power to the various parts of the radiation imaging device 10, and the like.

[0086] The operation panel 30 functions as an operation unit for operating each unit of the radiation imaging device 10 by inputting operation commands to each unit, and functions as a display unit for displaying various information such as warning messages and radiation images output from the image receiving unit 20 .

[0087] (Structure of control unit)

[0088] The control unit 28 controls the tube voltage, tube current, and radiation exposure time of the radiation tube 32 by sending a control signal to the radiation tube 32 of the irradiation unit 18 described later. The energy of the radiation is controlled by controlling the tube voltage by the control unit 28. In addition, the dose of the radiation is controlled by controlling the tube current and the irradiation time by the control unit 28. 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 imaging, imaging conditions including the tube voltage, tube current, and irradiation time are set through the operation panel 30. The control unit 28 operates the irradiation unit 18 according to the set imaging conditions.

[0089] The control unit 28 can perform animation photography of the subject H by causing the irradiation unit 18 to perform animation photography irradiation by continuously irradiating radiation from the irradiation unit 18. When performing animation photography, the control unit 28 causes the detector of the image receiving unit 20 described later to operate synchronously with the animation photography irradiation of the irradiation unit 18. When performing animation photography, basically, the irradiation time is not set as a photography condition, and commands for starting and ending the animation photography are issued through the operation panel 30. When a command for starting animation photography is input, the control unit 28 starts irradiating radiation from the irradiation unit 18 under the photography conditions set in advance.

[0090] In animation photography, when performing irradiation for animation photography, the detector repeatedly performs image detection at a preset frame rate. The image output by the detector is sent to the control unit 28. The control unit 28 sequentially outputs the received images to a monitor (not shown). As a result, an animation of the subject H is displayed on the monitor.

[0091] Furthermore, the control unit 28 can perform still image photography of the subject H by causing the irradiation unit 18 to execute irradiation for still image photography in which the irradiation unit 18 irradiates radiation in a shorter time than irradiation for moving image photography.

[0092] In still image photography, the control unit 28 causes the detector of the image receiving unit 20 to operate synchronously 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 a 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, so when the set irradiation time has passed, the irradiation of the irradiation unit 18 ends.

[0093] When the irradiation is finished, the detector starts to output the detected image. The image output by the detector is sent to the control unit 28. The control unit 28 stores the data of the still image in a memory not shown in the figure. And, the stored still image is displayed on a monitor not shown in the figure. Thus, a still image of the subject H is displayed on the monitor. And, in order to confirm the captured still image immediately after shooting, the still image can be displayed on the operation panel 30.

[0094] (Structure of irradiation section)

[0095] 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 position where the electrons collide with the target becomes a focus of the irradiated radiation.

[0096] 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 each side of the irradiation opening 34A and defines the irradiation opening 34A. The opening area of ​​the irradiation opening 34A is adjusted by changing the position of the shielding plate, thereby changing the irradiation field of the radiation irradiated from the irradiation unit 18.

[0097] 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 are fixed to the first end 12A of the arm 12. Figure 1 Only one of them is shown in the figure).

[0098] The pair of mounting plates 38 are arranged so as to sandwich both sides of the irradiation section 18 in the width direction, and are connected to both side surfaces of the irradiation section 18 in the width direction. Rotation shafts 36 are respectively provided protrudingly on the side surfaces of the irradiation section 18 that are opposite to the mounting plates 38, and the rotation shafts 36 are respectively supported on the pair of mounting plates 38 via bearings (not shown). Thus, the irradiation section 18 can rotate relative to the mounting plates 38 with the axis of the rotation shaft 36 as the rotation center, so that the direction of the irradiation opening 34A of the irradiation section 18 can be changed in the front-rear direction of the arm 12. The irradiation direction of the radiation can be changed by changing the direction of the irradiation opening 34A.

[0099] (Structure of image receiving unit)

[0100] like Figure 1 As shown, the image receiving unit 20 is provided at a position opposite to the irradiation unit 18, i.e., the second end 12B of the arm 12. In addition, in the present embodiment, the image receiving unit 20 is non-detachably fixed to the second end 12B of the arm 12, but the image receiving unit 20 may be detachably mounted to the second end 12B of the arm 12.

[0101] The image receiving unit 20 includes a detector in a housing. The image receiving unit 20 includes an image receiving surface 20A that receives radiation irradiated from the irradiation unit 18 and transmitted through the subject H. The radiation carrying information about the subject H is incident on the image receiving surface 20A.

[0102] The detector is, for example, a flat panel detector (FPD) of a digital radiography (DR) method. The FPD has a detection surface in which a plurality of pixels are arranged two-dimensionally and a thin film transistor (TFT) 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 converts radiation into a direct electrical signal may be used. Furthermore, as the image receiving unit 20, a structure other than the structure using an FPD may be used, for example, a structure combining an image intensifier (II; Image Intensifier) ​​and a camera may also be used.

[0103] (Cable structure)

[0104] like Figure 4 As shown, the irradiation unit 18 and the image receiving unit 20 are connected to the control unit 28 (refer to Figure 1 ) and power supply circuits not shown in the figure.

[0105] like Figure 5 and Figure 6 As shown, the cable 40 includes a plurality of (for example, three in this embodiment) first cables 42 and a plurality of (for example, three in this embodiment) second cables 44. The first cable 42 is used to connect the radiation tube 32 (refer to Figure 1 ) applied voltage, such as Figure 4As shown, one end is electrically connected to the irradiation portion 18 provided at the first end portion 12A of the arm 12 .

[0106] On the other hand, the second cable 44 supplies driving power to the image receiving unit 20 and relays the control unit 28 (see Figure 1 ) and the detector in the image receiving unit 20. The various signals include, in addition to the control signal sent from the control unit 28 to the detector, image signals sent from the detector to the control unit 28. One end of the second cable 44 is electrically connected to the image receiving unit 20 provided at the second end 12B of the arm 12. In addition, the second cable 44 is arranged inside the arm 12 and extends along the arm 12 to the first end 12A of the arm 12.

[0107] like Figure 5 As shown, the arm 12 is composed of a cylindrical body having a cavity inside, and has a first hollow portion 46 provided on the inner peripheral side (front side) and a second hollow portion 48 provided on the outer peripheral side (rear side). The second cable 44 is disposed in the first hollow portion 46 inside the arm 12.

[0108] And, if Figure 4 and Figure 6 As shown, a holding member 50 for holding one end of the cable 40 extending from the support portion 14 is provided at the first end portion 12A of the arm 12. In the holding member 50, the cable 40 is branched into a first cable 42 and a second cable 44. With the holding member 50 as a base point, the first cable 42 extends to the irradiation portion 18 and is connected to the irradiation portion 18. On the other hand, the second cable 44 extends to the image receiving portion 20 and is connected to the image receiving portion 20.

[0109] In other words, the first cable 42 having one end connected to the irradiation unit 18 and the second cable 44 having one end connected to the image receiving unit 20 are fixed to the first end 12A of the arm 12 by the holding member 50 and bundled into one cable group. The bundled one cable group is disposed as the cable 40 on the outer periphery of the arm 12 and extends from the first end 12A toward the support portion 14 along the outer periphery of the arm 12.

[0110] (Structure of belt)

[0111] And, if Figure 4 As shown, one end of a belt 52 as a tension member is fixed to the second end 12B of the arm 12. The belt 52 is a member for applying tension to the cable 40 and is disposed along the outer periphery of the arm 12 from the second end 12B of the arm 12 toward the support portion 14.

[0112] Specifically, if Figure 5As shown in FIG. 1 , a groove 48A extending along the arc of the arm 12 is formed on the inner side surface of the front side of the second hollow portion 48 of the arm 12, and the belt 52 extends along the arc of the arm 12 when accommodated in the groove 48A. The belt 52 is flat and has a Figure 5 The belt 52 is disposed in a posture with the long side direction in the Y direction and the short side direction (thickness direction) in the X direction in the cross-sectional shape shown. The thickness D2 of the belt 52 is thinner than the diameter (thickness) D1 of the cable 40 .

[0113] (Structure of reel unit)

[0114] like Figure 4 As shown in FIG. 1 , a reel unit 54 is provided in the support portion 14 of the radiation imaging device 10. The reel unit 54 reels in and delivers the cable 40 and the belt 52 as the arm 12 rotates along the track. Figure 7 As shown, the reel unit 54 includes a first reel 56 and a second reel 58 that is rotatably provided independently of the first reel 56 .

[0115] like Fig. 8A As shown, the first reel 56 includes a cylindrical winding portion 56A and a pair of flanges 56B provided on both end surfaces of the winding portion 56A. On the other hand, the second reel 58 includes a cylindrical winding portion 58A and a flange 58B provided on one end surface of the winding portion 58A.

[0116] The first winding shaft 56 is formed with an axial hole 60, and the second winding shaft 58 is formed with an axial hole 62. Fig.10 As shown in FIG. 1 , a rotating shaft 64 is inserted through each of the shaft hole 60 and the shaft hole 62 via a bearing portion (not shown). The rotating shaft 64 (see FIG. 1 ) Figure 7 ) is cylindrical, and both ends in the axial direction are fixed to a frame (not shown) of the support portion 14. Thus, the first reel 56 and the second reel 58 can rotate independently on the same axis with the axis of the rotating shaft 64 as the rotation center.

[0117] At the first end portion 12A of the arm 12 (reference Figure 4 ) The cable 40 having one end fixed thereto extends to the support portion 14 and is wound around the winding portion 56A of the first winding shaft 56 in the support portion 14. Fig.10 As shown, the other end of the cable 40 is introduced into the first reel 56, passes through the rotating shaft 64 and extends to Figure 1 and Figure 4 The main body 16 shown in FIG. 1 is respectively connected to the control unit 28 (reference Figure 1 ) and power supply circuits not shown in the figure.

[0118] On the other hand, at the second end portion 12B of the arm 12 (reference Figure 4) The belt 52 with one end fixed thereto extends to the support portion 14 and is wound around the winding portion 58A of the second winding shaft 58 in the support portion 14. The other end of the belt 52 is fixed to the support portion 14 by a fixing member 66 (see Fig.10 ) is fixed to the outer peripheral surface of the winding portion 58A of the second reel 58.

[0119] like Fig. 8A As shown, the first reel 56 and the second reel 58 are arranged in parallel along the axial direction of the rotating shaft 64, and the axially opposed portions thereof are in contact with each other. Specifically, one flange 56B of the first reel 56 abuts against the winding portion 58A of the second reel 58.

[0120] And, if Fig. 9A and Fig. 9B As shown, in the present embodiment, the first radius E1 of the winding portion 56A of the first reel 56 when the cable 40 is not wound is smaller than the second radius E2 of the winding portion 58A of the second reel 58 when the belt 52 is not wound. Furthermore, the difference (E2-E1) between the first radius E1 and the second radius E2 is equal to the difference (D1-D2) between the diameter (thickness) D1 of the cable 40 and the thickness D2 of the belt 52.

[0121] That is, also like Fig.10 As shown, the sum (E1+D1) of the first radius E1 of the winding portion 56A of the first reel 56 and the diameter D1 of the cable 40 is equal to the sum (E2+D2) of the second radius E2 of the winding portion 58A of the second reel 58 and the thickness D2 of the belt 52. Thus, when the cable 40 and the belt 52 are wound around the first reel 56 and the second reel 58 by one turn, respectively, the winding circumference of the cable 40 and the winding circumference of the belt 52 become equal.

[0122] The winding circumference RL refers to the winding amount of the cable 40 and the tape 52 per unit rotation amount of each of the first reel 56 and the second reel 58. The winding circumference RL increases as the winding amount of the cable 40 and the tape 52 increases.

[0123] For example, the winding circumference RL1(1) of the cable 40 of the first turn on the first reel 56 is a circumference corresponding to the length of the first radius E1. Specifically, it becomes RL1(1)=2×E1×π. Moreover, the winding circumference RL1(2) of the cable 40 of the second turn is a circumference corresponding to the length obtained by adding the first radius E1 and the diameter D1 of the cable 40. Specifically, it becomes RL1(2)=2×(E1+D1)×π. Moreover, the winding circumference RL1(3) of the cable 40 of the third turn is a circumference corresponding to the length obtained by adding the first radius E1 and twice the diameter D1. Specifically, it becomes RL1(3)=2×(E1+2×D1)×π.

[0124] Similarly, the winding circumference RL2(1) of the first turn of the belt 52 on the second reel 58 is a circumference corresponding to the length of the second radius E2. Specifically, it becomes RL2(1) = 2×E2×π. Moreover, the winding circumference RL2(2) of the second turn of the belt 52 is a circumference corresponding to the length obtained by adding the second radius E2 and the thickness D2 of the belt 52. Specifically, it becomes RL2(2) = 2×(E2+D2)×π. Moreover, the winding circumference RL2(3) of the third turn of the belt 520 is a circumference corresponding to the length obtained by adding the second radius E2 and twice the thickness D2. Specifically, it becomes RL2(3) = 2×(E2+2×D2)×π.

[0125] Thus, as the amount of the cable 40 and the tape 52 taken up increases, the take-up circumference RL1 of the cable 40 on the first reel 56 and the take-up circumference RL2 of the tape 52 on the second reel 58 become longer. Furthermore, when there is a difference ΔD (ΔD=D1-D2) between the diameter D1 of the cable 40 and the thickness D2 of the tape 52, the change rates of the take-up circumference RL1 and the take-up circumference RL2 differ according to the difference ΔD. Therefore, according to the amount of the cable 40 and the tape 52 taken up, a circumference difference ΔRL (ΔRL=RL1-RL2) is generated between the take-up circumference RL1 and the take-up circumference RL2.

[0126] In this example, the first radius E1 of the first reel 56 and the second radius E2 of the second reel 58 are different, but the difference between the first radius E1 and the second radius E2 is not the root cause of the circumference difference ΔRL that is a problem in the technology of the present invention. The root cause of the circumference difference ΔRL that is a problem in the technology of the present invention is that the diameter D1 of the cable 40 and the thickness D2 of the belt 52 are different. Therefore, the first radius E1 and the second radius E2 may be the same, and the circumference difference ΔRL will also occur in this case.

[0127] (Structure of the rotational force transmission component)

[0128] And, if Fig. 8A As shown in the figure, a spring 68 as a rotation force transmission member is provided between the first reel 56 and the second reel 58. The spring 68 is, for example, a tension coil spring. A first pin 70A is protrudingly provided on the outer surface of one of the flanges 56B of the first reel 56 that faces the second reel 58. On the other hand, a second pin 70B is protrudingly provided on the inner surface of the flange 58B that faces the first reel 56 inside the winding portion 58A of the second reel 58.

[0129] like Figure 8BAs shown, one end of the spring 68 is fixed to the first pin 70A and the other end is fixed to the second pin 70B, and the first spool 56 and the second spool 58 are connected by the spring 68. The spring 68 expands and contracts when the first spool 56 and the second spool 58 are rotated in opposite directions.

[0130] When one of the first reel 56 and the second reel 58 rotates, the rotational force in the same direction is transmitted to the other reel by the spring 68. Specifically, when the arm 12 is moved in the first direction ( Figure 4 When the track rotates (in the direction of the arrow M1 in the figure), the second end 12B of the arm 12 moves in a direction away from the support portion 14. When the second end 12B moves in a direction away from the support portion 14, the belt 52 fixed at one end to the second end 12B is fed out from the second reel 58. As a result, the second reel 58 on which the belt 52 is wound is fed out in the direction (in the direction of the arrow M1 in the figure). Figure 7 and Figure 8B Rotate in the direction of arrow F1).

[0131] At this time, the rotation force of the second spool 58 is applied by the spring 68 (see Fig.10 ) is transmitted to the first scroll 56, and the first scroll 56 is transmitted in the same direction as the second scroll 58 ( Figure 7 and Figure 8B The rotation in the direction of arrow F1 is the rotation in the direction in which the first reel 56 takes up the cable 40. Therefore, by rotating the first reel 56 in the direction of arrow F1, the cable 40 is taken up on the first reel 56. Figure 4 If the track rotates in the direction of arrow M1 in FIG. 1 , the cable 40 is loosened. Therefore, by rotating the first reel 56 in the direction of arrow F1, the loosening of the cable 40 is suppressed.

[0132] On the other hand, when the arm 12 is moved along the second direction ( Figure 4 When the first end 12A of the arm 12 is rotated in the direction of the arrow M2 in the figure, the first end 12A of the arm 12 moves away from the support portion 14. When the second end 12B is moved toward the direction of the support portion 14, the cable 40 fixed at one end to the first end 12A is sent out. As a result, the first reel 56 wound with the cable 40 is moved in the direction of sending out the cable 40 ( Figure 7 and Figure 8B Rotate in the direction of arrow F2.

[0133] At this time, the rotation force of the first spool 56 is exerted by the spring 68 (see Fig.10 ) is transmitted to the second scroll 58, and the second scroll 58 is transmitted in the same direction as the first scroll 56 ( Figure 7 and Figure 8B The rotation in the direction of arrow F2 is the rotation in the direction in which the second reel 58 takes up the belt 52. Therefore, by rotating the second reel 58 in the direction of arrow F2, the belt 52 is taken up on the second reel 58. Figure 4 If the belt 52 is rotated in the direction of the arrow M2 in the track, the belt 52 is loosened. Therefore, by rotating the second reel 58 in the direction of the arrow F2, the loosening of the belt 52 is suppressed.

[0134] Furthermore, in the present embodiment, the spring 68 is fixed to the first reel 56 and the second reel 58 in a state where the spring 68 is stretched to a predetermined length relative to the natural length. That is, in a state where the spring 68 is fixed to the first reel 56 and the second reel 58, Figure 8B As shown, the spring 68 is in the contraction direction ( Figure 8B A force is generated in the direction of the arrow G in the figure.

[0135] The first spool 56 is moved in the winding direction ( Figure 8B The second reel 58 is forced in the direction of the arrow F1 in the drawing of the belt 52 ( Figure 8B Apply force in the direction of arrow F2.

[0136] Furthermore, when the spring 68 transmits the rotational force of one of the first reel 56 and the second reel 58 to the other reel, a difference is allowed to occur between the rotation amount of one of the first reel 56 and the second reel 58 and the rotation amount of the other reel within a preset range, that is, a range within which the spring 68 can be extended. Therefore, one of the first reel 56 and the second reel 58 can rotate relative to the other reel following the force of the spring 68 or resisting the force of the spring 68.

[0137] (Effect)

[0138] Next, the effects of the radiation imaging device 10 according to the present embodiment will be described. Figure 11 to Figure 14 Provide explanation. Fig.11 and Fig.12 The arm 12 and the support part 14 of the radiation imaging device 10 of this embodiment are shown. Fig.13 and Fig.14 The arm 120 and the support part 140 of the comparative example radiation imaging device 100 are shown. The radiation imaging device 10 of the present embodiment is different from the radiation imaging device 100 of the comparative example in that the comparative example does not have the spring 68 as a rotation force transmission member and the first spool 56 and the second spool 58 are formed integrally and always rotate in the same direction.

[0139] In addition, if Figure 7 As shown in FIG. 1 , when the radiation imaging device 10 is viewed from the side (from the Y direction), the first reel 56 and the second reel 58 constituting the reel unit 54 are arranged at positions overlapping each other. Figure 11 to Figure 14 In the figure, for convenience of explanation, the first scroll 56 and the second scroll 58 are arranged at positions shifted in the vertical direction (Z direction).

[0140] like Fig.11 As shown in the figure, when the arm 12 is orbitally rotated in the first direction (arrow M1 direction) in which the first end 12A of the arm 12 approaches the support portion 14, the cable 40 having one end fixed to the first end 12A also approaches the support portion 14 as the first end 12A moves. At this time, in order to suppress the slack of the cable 40, it is necessary to apply tension to the cable 40 by winding the cable 40 on the first reel 56 provided in the support portion 14.

[0141] The belt 52 is a member for applying tension to the cable 40, and one end of the belt 52 is fixed to the second end portion 12B of the arm 12. Therefore, when the arm 12 is orbitally rotated in the first direction (arrow M1 direction), the belt 52 is fed out from the second reel 58. The first reel 56 and the second reel 58 are held so as to be independently rotatable, but when one of the first reel 56 and the second reel 58 rotates, the rotational force in the same direction is transmitted to the other reel by the spring 68.

[0142] That is, when the arm 12 is orbitally rotated in the first direction (arrow M1 direction), the first end 12A of the arm 12 approaches the support portion 14, while the second end 12B of the arm 12 moves away from the support portion 14. As a result, the belt 52 having one end fixed to the second end 12B is fed out from the second reel 58, and the second reel 58 rotates in the feeding direction of the belt 52.

[0143] Furthermore, the rotational force of the second reel 58 is transmitted to the first reel 56 via the spring 68, so that the first reel 56 rotates in the same direction as the second reel 58. The rotational direction is the feeding direction of the belt 52 in the second reel 58, and is the winding direction of the cable 40 in the first reel 56. Thus, even when the arm 12 is orbitally rotated in the first direction (arrow M1 direction), the cable 40 is wound on the first reel 56. Thus, tension is applied to the cable 40, thereby suppressing the slack of the cable 40.

[0144] The spring 68 urges the first reel 56 in the winding direction of the cable 40 and urges the second reel 58 in the winding direction of the belt 52. In addition, when the spring 68 transmits the rotational force, a difference is allowed to occur between the rotation amount of the first reel 56 and the rotation amount of the second reel 58 within a preset range. Thus, the following effects can be obtained.

[0145] That is, if there is a difference between the diameter D1 of the cable 40 and the thickness D2 of the belt 52, as shown in Figure 9, due to the thickness difference ΔD (ΔD=D1-D2), a circumference difference ΔRL (ΔRL=RL1-RL2) is generated between the winding circumference RL1 of the cable 40 around the first reel 56 and the winding circumference RL2 of the belt 52 around the second reel 58.

[0146] If the amount of cable 40 wound on the first reel 56 changes, the diameter of the first reel 56 changes, and thus the winding circumference RL1 also changes. As described above, if the winding circumference RL1(1) of the cable 40 wound on the first reel 56 for the first turn is set, the winding circumference RL1(2) of the cable 40 wound on the second turn is longer. This is because the diameter of the first reel 56 for the second turn is increased by the diameter of the cable 40 wound on the first turn. The same is true for the second reel 58.

[0147] If the diameter D1 of the cable 40 and the thickness D2 of the tape 52 are the same, the difference ΔD is zero. Therefore, even if the winding circumferences RL1 and RL2 of the first and second turns of the first reel 56 and the second reel 58 change, the changes in the winding circumferences RL1 and RL2 are the same. Therefore, between the first reel 56 and the second reel 58 rotating at the same time, there is no circumference difference ΔRL between the winding circumference RL1 of the cable 40 of the first reel 56 and the winding circumference RL2 of the tape 52 of the second reel 58.

[0148] However, in this embodiment, the diameter D1 of the cable 40 is larger than the thickness D2 of the belt. The belt 52 is a member for applying tension, so the thickness D2 is small, and the change in the winding circumference RL2 according to the rotation amount of the second reel 58 is negligible. On the other hand, the cable 40 electrically connected to the irradiation unit 18 is a cable for applying a high voltage, so the diameter D1 is larger than that of a simple control signal cable. Therefore, the change in the winding circumference RL1 according to the rotation amount of the first reel 56 cannot be ignored, and the difference ΔD with the thickness of the belt 52 is also large.

[0149] Therefore, the winding circumference RL1 of the cable 40 of the first reel 56 and the winding circumference RL2 of the belt 52 of the second reel 58 change to a non-negligible degree according to the change in the winding amount of the first reel 56. If the circumference difference ΔRL between the winding circumferences RL1 and RL2 of the first reel 56 and the second reel 58 is generated in this way, the following problem occurs.

[0150] For example, when the winding circumference RL1 of the cable 40 on the first reel 56 is longer than the winding circumference RL2 of the tape 52 on the second reel 58 , two cases, namely the first case and the second case shown below, are considered.

[0151] The first situation is as follows: Fig.13 As shown in the comparative example, the arm 12 is orbitally rotated in the first direction (arrow M1 direction), so that the tape 52 is fed out by the second reel 58, and the cable 40 is wound up by the first reel 56. In the first case, if the rotation amount of the second reel 58 is completely consistent with the rotation amount of the first reel 56, the winding amount of the cable 40 of the first reel 56 increases relative to the feeding amount of the tape 52 of the second reel 58, and a tension greater than necessary is applied to the cable 40.

[0152] That is, when the arm 12 is rotated along the first direction track, the amount P of the tape 52 fed from the second reel 58 is determined by the amount of movement of the arm 12 (referred to as P). The amount of rotation of the second reel 58 is determined by the amount of feeding P. The first reel 56 also rotates in the same direction as the second reel 58 by the same amount.

[0153] Since the diameter D1 of the cable 40 is larger than the thickness D2 of the tape 52, the winding circumference RL1 of the first reel 56 is longer than the winding circumference RL2 of the second reel 58. Therefore, the winding amount P+d of the cable 40 of the first reel 56 is longer than the feeding amount P of the tape 52 of the second reel 58. Therefore, a tension exceeding the tension required to suppress slack is applied to the cable 40. If the tension is too large, the cable 40 may break.

[0154] And, the second situation is as follows: Fig.14 As shown in FIG. 1 as a comparative example, the arm 12 is orbitally rotated in the second direction (arrow M2 direction), so that the cable 40 is fed out by the first reel 56, and the tape 52 is wound up by the second reel 58. In the second case, if the rotation amount of the second reel 58 is completely consistent with the rotation amount of the first reel 56, the wound amount of the tape 52 of the second reel 58 becomes less than the feeding amount of the cable 40 of the first reel 56. Therefore, the tape 52 is loosened. Symbol 52A represents the bent portion of the tape 52.

[0155] That is, when the arm 12 is rotated along the second direction track, the amount P of the cable 40 fed from the first reel 56 is determined by the amount of movement of the arm 12 (referred to as P). The amount of rotation of the first reel 56 is determined by the amount of feed P. The second reel 58 also rotates in the same direction as the first reel 56 by the same amount.

[0156] Since the diameter D1 of the cable 40 is larger than the thickness D2 of the tape 52, the winding circumference RL2 of the second reel 58 is shorter than the winding circumference RL1 of the first reel 56. Therefore, the winding amount P-α of the tape 52 of the second reel 58 is shorter than the feeding amount P of the cable 40 of the first reel 56. Therefore, the tape 52 is slack.

[0157] On the other hand, Fig.11 and Fig.12As shown, in the radiation imaging device 10 of the present embodiment, the first reel 56 and the second reel 58 are connected by a spring 68 as a rotational force transmitting member. When one of the first reel 56 and the second reel 58 rotates, the spring 68 not only transmits the rotational force in the same direction to the other reel, but also urges the first reel 56 in the winding direction of the cable 40 and urges the second reel 58 in the winding direction of the belt 52. In addition, when the spring 68 transmits the rotational force, a difference between the rotation amount of the first reel 56 and the rotation amount of the second reel 58 is allowed to occur within a preset range.

[0158] exist Fig.13 In the first case shown, the winding amount P+α of the cable 40 is longer than the movement amount P of the arm 12. Therefore, the spring 68 applies a tension greater than necessary to the cable 40 that exceeds the tension required for winding, with the force of the spring 68 urging the first spool 56 in the winding direction.

[0159] In the first case, according to the radiation imaging device 10 of this embodiment, as Fig.11 As shown, the tension applied to the cable 40 extends the spring 68, so that the rotation amount of the first reel 56 decreases relative to the rotation amount of the second reel 58. That is, the first reel 56 rotates relative to the second reel 58 in the direction of feeding the cable 40 against the urging force of the spring 68.

[0160] The amount of rotation of the first reel 56 in the winding direction is reduced, so that the winding amount P of the cable 40 and the movement amount P of the arm 12 become equal, and the tension acting on the cable 40 from the first reel 56 is relieved. As a result, the tension more than necessary is suppressed from being applied to the cable 40 due to the difference ΔRL between the winding circumference RL1 of the first reel 56 and the winding circumference RL2 of the second reel 58, thereby suppressing the possibility of the cable 40 being broken.

[0161] And, in Fig.14 In the second case shown, the winding amount Pd of the belt 52 is shorter than the movement amount P of the arm 12 due to the difference between the winding circumference RL1 of the first reel 56 and the winding circumference RL2 of the second reel 58 , so that the belt 52 is slack.

[0162] In the second case, according to the radiation imaging device 10 of this embodiment, as Fig.12 As shown, by contracting the spring 68, the rotation amount of the second reel 58 increases relative to the rotation amount of the first reel 56. That is, the second reel 58 rotates in the direction of winding the belt 52 by the force of the spring 68 that urges the second reel 58 in the winding direction of the belt 52. The rotation amount of the second reel 58 in the winding direction increases, so that the winding amount P of the belt 52 and the movement amount P of the arm 12 become equal, and the slack of the belt 52 is suppressed. Fig.12 In, no Fig.14 The slack 52A of the strap 52 is shown.

[0163] That is, according to the radiation imaging device 10 of the present embodiment, the spring 68 urges the first reel 56 in the winding direction of the cable 40 and urges the second reel 58 in the winding direction of the belt 52. Thus, the cable 40 and the belt 52 wound around the first reel 56 and the second reel 58 are prevented from loosening.

[0164] The spring 68 allows a difference in the amount of rotation of the first spool 56 and the second spool 58 , thereby preventing more tension than necessary from being applied to the cable 40 and the belt 52 due to a difference in the winding circumference of the first spool 56 and the second spool 58 .

[0165] Furthermore, the reason why the first reel 56 and the second reel 58 can rotate independently is because it is necessary as a prerequisite for realizing the function of the spring 68. That is, the winding direction of the cable 40 of the first reel 56 and the winding direction of the belt 52 of the second reel 58 are opposite to each other in rotation direction, so it is necessary to make the first reel 56 and the second reel 58 rotate independently. Furthermore, in order to allow the difference in the rotation amount of the first reel 56 and the second reel 58, it is also necessary to make the first reel 56 and the second reel 58 rotate independently. The above functions can be realized by connecting the first reel 56 and the second reel 58 that can rotate independently with the spring 68.

[0166] Therefore, there is no need to perform complicated processing such as manufacturing a tapered pulley with a spiral guide groove as in the past. Therefore, the problem of applying more tension than necessary to the cable 40 and the belt 52 and the problem of loosening of the cable 40 and the belt 52 can be solved more simply.

[0167] Furthermore, according to this embodiment, the first reel 56 and the second reel 58 constituting the reel unit 54 are coaxially arranged around the same rotation axis 64. Therefore, compared with a structure in which the first reel 56 and the second reel 58 are arranged on different axes, the structure becomes simpler and space can be saved.

[0168] Furthermore, according to the present embodiment, the first reel 56 and the second reel 58 are respectively provided in the support portion 14 of the radiation imaging device 10. The support portion 14 is a connecting portion between the arm 12 and the main body 16, and therefore functions as a relay portion of the cable 40 between the arm 12 and the main body 16. By providing the first reel 56 here, wiring of the cable 40 is facilitated.

[0169] Furthermore, the support portion 14 is a portion that becomes the base point of the arm 12 that orbits, and therefore, from the viewpoint of suppressing the complexity of the structure, the support portion 14 is the best position for introducing the cable 40 and the belt 52 disposed on the outer periphery of the arm 12. By providing the first reel 56 and the second reel 58 at this position, the complexity of the structure can be suppressed.

[0170] Furthermore, according to the present embodiment, the diameter (thickness) D1 of the cable 40 is greater than the thickness D2 of the belt 52, and the first radius E1 of the winding portion 56A of the first reel 56 when the cable 40 is not wound is smaller than the second radius E2 of the winding portion 58A of the second reel 58 when the belt 52 is not wound.

[0171] Thus, in the present embodiment, the first radius E1 of the winding portion 56A of the first reel 56 for winding the cable 40 having the diameter D1 is made smaller than the second radius E2 of the winding portion 58A of the second reel 58 for winding the tape 52 having the thickness D2 smaller than the diameter D1. The winding circumference RL1 of the first reel 56 for winding the cable 40 (diameter D1) becomes longer than the winding circumference RL2 of the tape 52 (thickness D2) of the second reel 58 as the winding amount increases.

[0172] By making the first radius E1 smaller than the second radius E2 in the initial state when the cable 40 and the belt 52 are not wound, it is possible to suppress the circumference difference ΔRL between the winding circumference RL1 of the cable 40 and the winding circumference RL2 of the belt 52 from increasing excessively when the cable 40 and the belt 52 are wound by the first reel 56 and the second reel 58.

[0173] The details are as follows. The state in which the winding amount of the cable 40 in the first reel 56 becomes the smallest is when the arm 12 is moved along the second direction ( Fig.12 The state in which the first end portion 12A is moved to the maximum extent in the second direction is when the arm 12 is rotated along the first direction orbit and the second end portion 12B is moved to the first direction (the arrow M2 direction). Fig.11 The first radius E1 is small, etc., which means that the winding circumference RL1(1) of the first turn of the cable 40 based on the first reel 56 is shorter than the winding circumference RL2(1) of the first turn of the belt 52 based on the second reel 58.

[0174] If we consider the case where the first end portion 12A is moved in the second direction ( Fig.12 The arm 12 is moved in the first direction ( Fig.11In the case of orbital rotation (in the direction of arrow M1), the smaller the first radius E1 of the first reel 56 is than the second radius E2 of the second reel 58, the smaller the winding amount of the cable 40 of the first reel 56 becomes relative to the feeding amount of the belt 52 of the second reel 58. Therefore, the smaller the first radius E1 is than the second radius E2, the more the tension applied to the cable 40 can be suppressed by winding up the first reel 56. On the other hand, the slack of the cable 40 increases.

[0175] Thus, if the first radius E1 is made smaller than the second radius E2, there is an advantage of suppressing the tension applied to the cable 40 more than necessary, but there are disadvantages such as increased slack of the cable 40. However, applying a tension more than necessary to the cable 40 is usually not preferred because it may cause the cable 40 to break. Therefore, by making the first radius E1 of the first reel 56 smaller than the second radius E2 of the second reel 58, advantages that outweigh the disadvantages such as increased slack of the cable 40 can be obtained.

[0176] In particular, according to the present embodiment, the difference between the first radius E1 and the second radius E2 is equal to the difference between the diameter (thickness) D1 of the cable 40 and the thickness D2 of the tape 52. That is, when the cable 40 and the tape 52 are respectively wound one turn on the first reel 56 and the second reel 58, the winding circumference RL1 of the cable 40 and the winding circumference RL2 of the tape 52 become equal.

[0177] In this way, by making the winding circumference RL1(1) of the first reel 56 in the state of winding the cable 40 J turns and the winding circumference RL2(1) of the second reel 58 in the state of winding the tape 52 1 turn equal, it is possible to reduce the maximum value of the difference ΔRL between the winding circumference RL1 of the cable 40 and the winding circumference RL2 of the tape 52 when the cable 40 is wound multiple times. In other words, it is possible to suppress the circumference difference ΔRL between the winding circumference RL1 of the cable 40 and the winding circumference RL2 of the tape 52 from increasing too much.

[0178] Furthermore, according to the present embodiment, the cable 40 includes a first cable 42 for applying a voltage to the radiation tube 32 of the irradiation unit 18. Generally, the voltage applied to the radiation tube 32 is relatively high. Therefore, the thickness of the insulating coating of the cable for applying the voltage becomes thicker, and the diameter tends to become larger. On the other hand, the belt 52 only needs to be able to apply tension, so the thickness can be reduced.

[0179] Thus, when the cable 40 includes the first cable 42 for applying voltage to the radiation tube 32, the circumference difference ΔRL between the winding circumference RL1 of the first reel 56 and the winding circumference RL2 of the second reel 58 tends to increase. Therefore, it is highly necessary to adopt the technology of this embodiment.

[0180] Furthermore, the cable 40 includes a second cable 44 connected to the image receiving unit 20 in addition to the first cable 42. The first cable 42 and the second cable 44 are arranged on the outer periphery of the arm 12 as a bundled cable group between the first reel 56 and the first end 12A of the arm 12.

[0181] Furthermore, a cable group (cable 40) is fixed to the first end 12A by a holding member 50. Furthermore, based on the position where the cable group is fixed, the first cable 42 and the second cable 44 are branched on the side opposite to the first reel 56, so that the first cable 42 is connected to the irradiation unit 18 provided at the first end 12A. On the other hand, the second cable 44 is extended to the second end 12B by being arranged inside the arm 12, and is connected to the image receiving unit 20 provided at the second end 12B.

[0182] In this way, the cable group (cable 40) is fixed, and based on the fixed position, the first cable 42 and the second cable 44 are branched on the side opposite to the first reel 56. This prevents the tension applied to the cable group (cable 40) and the slack generated in the cable group (cable 40) from affecting the first cable 42 and the second cable 44.

[0183] Furthermore, the cables 40 are arranged on the outer periphery of the arm 12 as a cable group formed by bundling the first cable 42 and the second cable 44 between the first reel 56 and the first end 12A. Thus, the cables 40 arranged on the outer periphery of the arm 12 can be gathered on the first end 12A side of the arm 12. Therefore, in the outer periphery of the arm 12, the complication of the electric wiring can be suppressed compared to the case where the cables 40 are arranged separately on the first end 12A and the second end 12B.

[0184] Furthermore, in the present embodiment, the cable group (cable 40) is disposed between the first end 12A of the arm 12 provided with the irradiation unit 18 and the support unit 14. Generally, when the radiation imaging device 10 is used for video imaging, the irradiation unit 18 is often disposed below the subject H, and the image receiving unit 20 is often disposed above the subject H. Video imaging is often performed during surgery, and in this case, it is not preferable that the portion of the cable 40 on the arm 12 be disposed above the subject H. This is because, for example, if the cable 40 is loose above the subject H, the surgery may be obstructed.

[0185] Among them, by arranging the cable group (cable 40) between the first end 12A and the support part 14, which is mostly arranged below the subject H during animation shooting, the arrangement portion of the cable 40 can be arranged on the arm 12 below the subject H during animation shooting.

[0186] Furthermore, according to the present embodiment, the other end of the belt 52 is fixed to the outer peripheral surface of the second reel 58 by the fixing member 66. In this way, by fixing the other end of the belt 52 to the second reel 58, for example, compared with a structure in which both ends of the belt 52 are respectively fixed to one end and the other end of the arm 12 via the second reel 58, the length of the belt 52 can be shortened, thereby suppressing the complexity of the structure of the second reel 58.

[0187] Furthermore, according to the present embodiment, the tape 52 is used as the tension member. Thus, by using the tape 52 as the tension member, the thickness of the tension member can be reduced, and tension can be applied to the cable 40 by the tension member.

[0188] Furthermore, according to the present embodiment, the spring 68 connects the first reel 56 and the second reel 58, and expands and contracts when the first reel 56 and the second reel 58 are rotated in opposite directions. The spring 68 constitutes a rotational force transmission member. Thus, by using the spring 68 as a rotational force transmission member, the rotational force can be transmitted with a simple structure, and the first reel 56 and the second reel 58 are urged in the winding directions of the cable 40 and the belt 52, respectively.

[0189] In particular, according to the present embodiment, one end of the spring 68 is mounted on the first pin 70A provided on the side surface of the first reel 56, and the other end is mounted on the second pin 70B provided on the side surface of the second reel 58. In this way, by providing the first pin 70A and the second pin 70B, on both ends of the spring 68, on the side surface of the first reel 56 and the side surface of the second reel 58, respectively, the spring 68 can be mounted on the first reel 56 and the second reel 58 with a simple structure.

[0190] <Other embodiments>

[0191] As mentioned above, although an example of embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and can be implemented in various forms within the scope not departing from the gist of the present invention.

[0192] For example, in the above embodiment, the belt 52 is used as the tension member, but it is not limited to the belt 52 as long as it can apply tension to the cable 40. However, the thickness of the tension member is preferably smaller than the cable 40, and a belt or a wire is preferably used as the tension member.

[0193] Furthermore, in the above-mentioned embodiment, the spring 68 is used as the rotational force transmission member. However, the rotational force transmission member is not limited to the spring 68 as long as it can transmit the rotational force of one of the first reel 56 and the second reel 58 to the other reel, apply force to the first reel 56 and the second reel 58 in the winding direction of the cable 40 and the belt 52, respectively, and allow a difference to be generated between the rotation amount of the first reel 56 and the rotation amount of the second reel 58. As the rotational force transmission member, for example, a rubber member or a magnet can be used in addition to the spring 68.

[0194] Furthermore, in the above-described embodiment, the first reel 56 and the second reel 58 are arranged around the same rotation axis 64, but they may be arranged around different rotation axes. Fig.11 and Fig.12 In the figure, as shown for the sake of convenience, different rotation axes can be set on the same axis as each other, or on different axes.

[0195] Furthermore, in the above embodiment, the first reel 56 and the second reel 58 are respectively disposed in the support portion 14 of the radiographic device 10. However, the first reel 56 and the second reel 58 do not necessarily need to be disposed in the support portion 14, and may be disposed in the main body 16 of the radiographic device 10, for example.

[0196] Furthermore, in the above-mentioned embodiment, the first radius E1 of the winding portion 56A of the first reel 56 is smaller than the second radius E2 of the winding portion 58A of the second reel 58, but the first radius E1 and the second radius E2 may be the same. Furthermore, when the thickness of the tension member is larger than the diameter D1 of the cable 40, the first radius E1 of the winding portion 56A of the first reel 56 may be larger than the second radius E2 of the winding portion 58A of the second reel 58.

[0197] Furthermore, in the above-described embodiment, X-rays are described as an example of radiation, but the radiation is not limited to X-rays, and may be gamma rays or the like.

[0198] The invention of Japanese Patent Application No. 2019-199330 filed on October 31, 2019 is incorporated herein by reference in its 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 was specifically and individually described as being incorporated as a reference.

Claims

1. A radiation imaging device comprising: The arm can be provided with an irradiation unit for irradiating radiation at one of the first end and the second end, and an image receiving unit for receiving the radiation irradiated from the irradiation unit and transmitted through the subject is installed at the other end, wherein: The side surface of the arm is in an arc shape, and can perform orbital rotation so that the irradiation unit and the image receiving unit rotate around the object in an opposing posture; a support portion having a track portion engaged with the arc-shaped outer peripheral portion of the arm and supporting the arm in a manner capable of performing the orbital rotation; a cable having one end electrically connected to at least one of the irradiation section and the image receiving section, and the cable being arranged along the outer circumference of the arm from the first end portion of the arm toward the support portion; a tension member for applying tension to the cable when the arm is orbitally rotated in a first direction in which the first end portion approaches the support portion, wherein one end of the tension member is fixed to the second end portion of the arm, and the tension member is arranged along the outer circumference of the arm from the second end portion toward the support portion; a first reel that rotates in a direction of winding up the cable when the arm is orbitally rotated in the first direction, and that rotates in a direction of feeding out the cable when the arm is orbitally rotated in a second direction in which the second end portion approaches the support portion; a second reel that rotates in a direction of feeding out the tension member when the arm is rotated in the orbit in the first direction, and that rotates in a direction of winding up the tension member when the arm is rotated in the orbit in the second direction, wherein the second reel is independently rotatable relative to the first reel; and A rotational force transmission component transmits a rotational force in the same direction to the other reel when one of the first reel and the second reel rotates, wherein the rotational force transmission component applies a force to the first reel in the winding direction of the cable and applies a force to the second reel in the winding direction of the tension component, and when transmitting the rotational force, a difference between the rotation amount of the first reel and the rotation amount of the second reel is allowed within a predetermined range.

2. The radiation imaging device according to claim 1, wherein: The first reel and the second reel are coaxially arranged.

3. The radiation imaging device according to claim 1, wherein: The first reel and the second reel are disposed in the support portion.

4. The radiation imaging device according to claim 1, wherein: In the case where the thickness of the cable is thicker than the thickness of the tension member, A first radius of the winding portion of the first reel when the cable is not wound is smaller than a second radius of the winding portion of the second reel when the tension member is not wound.

5. The radiation imaging device according to claim 4, wherein: The first radius is smaller than the second radius, and a difference between the first radius and the second radius is equal to a difference between a thickness of the cable and a thickness of the tension member.

6. The radiation imaging device according to claim 1, wherein: The cables include a first cable for applying a voltage to the radiation tube of the irradiation unit.

7. The radiation imaging device according to claim 6, wherein: The cable includes the first cable and a second cable connected to the image receiving unit. The first cable and the second cable are arranged as a bundled cable group on the outer periphery of the arm between the first reel and the first end, and the cable group is fixed to the first end. With the position where the cable group is fixed as a reference, the first cable and the second cable are branched on the side opposite to the first reel, so that one of the first cable and the second cable is connected to one of the irradiation part and the image receiving part arranged at the first end, and the other cable is extended to the second end by being arranged inside the arm, and is connected to the other of the irradiation part and the image receiving part arranged at the second end.

8. The radiation imaging device according to claim 1, wherein: The irradiation unit is provided at the first end portion.

9. The radiation imaging device according to claim 1, wherein: The other end of the tension member is fixed to the second reel.

10. The radiation imaging device according to claim 1, wherein: The tension member is a belt or a wire.

11. The radiation imaging device according to any one of claims 1 to 10, wherein: The rotation force transmission member is a spring that couples the first spool and the second spool and expands and contracts when the first spool and the second spool are rotated in opposite directions.

12. The radiation imaging device according to claim 11, wherein: One end of the spring is mounted on a first pin provided on a side surface of the first reel, and the other end of the spring is mounted on a second pin provided on a side surface of the second reel.

Images