JP2014033877A - X-ray imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen a life of an X-ray tube device by preventing abrasion of an anodic rotating shaft due to gyro effect in an X-ray imaging apparatus.SOLUTION: Even after rotary drive of an anode is stopped after X-ray irradiation, the anode rotates in its inertia. When anode rotational frequency due to its inertia is lower than a preset value, a brake release is allowed. Thus, an operator cannot move an X-ray tube device because a brake is not released even by pressing a brake release switch when the rotational frequency due to the inertia of an anode is equal to or more than the preset value. Therefore, the Coriolis force applied to the anode to be worn away due to pressing to a rotary bearing can be prevented.

Description

  The present invention relates to an X-ray imaging apparatus used in a hospital or the like, and more particularly to an X-ray imaging apparatus having a structure in which an X-ray tube apparatus is moved by being suspended from a ceiling.

  The X-ray imaging apparatus obtains an X-ray signal of a subject by irradiating the subject with X-rays and detecting transmitted X-rays with an X-ray detector or an X-ray film. The image processing unit generates an X-ray image by processing the X-ray signal and displays it on the display device.

  Such an X-ray imaging apparatus has various structures. For example, as disclosed in Patent Document 1, a ceiling in which an X-ray tube apparatus having an X-ray tube built in is suspended from the ceiling. There is a traveling X-ray imaging apparatus. This device can move the X-ray tube device linearly in two directions, linearly in the vertical direction, or rotate around the vertical or horizontal axis along a rail placed on the ceiling. is there. Thereby, it is possible to perform imaging while directing the X-ray irradiation direction to a desired imaging region of the subject in the standing position or the supine position. At that time, the operator can grasp the operation handle attached to the X-ray tube apparatus and press the operation switch provided in the vicinity of the operation handle to release the movement lock so that it can be manually moved in each direction. It is configured.

JP 2005-21470 A

  The X-ray tube includes a rotation mechanism that rotates the anode (target) during X-ray irradiation. Thereby, it is comprised so that an electron beam may not be continuously irradiated to the same position of an anode. After X-ray imaging, the anode continues to rotate by inertia, and the rotational speed gradually decreases and stops. For this reason, when the X-ray tube apparatus is linearly moved or rotated for the next imaging after X-ray imaging, the axis of rotation of the anode rotates by inertia, so that it is orthogonal to the moving direction due to the gyro effect. Coriolis force acts in the direction. Due to the Coriolis force, there is a problem that the rotating shaft of the anode is pressed against the bearing and is worn, thereby shortening the life of the anode.

  An object of the present invention is to prevent wear of the anode rotation shaft due to the gyro effect and to extend the life of the X-ray tube apparatus.

  In order to solve the above problems, the X-ray imaging apparatus of the present invention is configured to permit the release of the brake when the anode rotation speed due to inertia after X-ray irradiation of the X-ray tube is lower than a predetermined value. To do.

  According to the present invention, when the anode rotates by inertia after X-ray irradiation, the movement of the X-ray tube device is not permitted if the rotation speed is equal to or greater than a predetermined value. Therefore, it is possible to prevent the bearing from being pressed against the bearing by Coriolis force. Therefore, shaft wear can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the imaging device of 1st Embodiment. Explanatory drawing which shows the detailed structure of the X-ray tube 6. FIG. The front view of the operation part 4 of FIG. The functional block diagram of the holding | maintenance apparatus 2 of FIG. The graph which shows the relationship between the anode rotation speed of 1st Embodiment, and a movement permission signal. The flowchart which shows operation | movement of the movement permission part of 1st Embodiment. The graph which shows the relationship between the anode rotation speed of 2nd Embodiment, and a movement permission signal. The graph which shows the relationship between the anode rotation speed of 3rd Embodiment, and a movement permission signal. The graph which shows the relationship between the anode rotation speed of 4th Embodiment, and a movement permission signal. The flowchart which shows operation | movement of the movement permission part of 5th Embodiment. The flowchart which shows operation | movement of the movement permission part of 6th Embodiment. The graph which shows the relationship between the anode rotation speed of 7th Embodiment, and a movement permission signal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
The X-ray imaging apparatus of the present invention includes an X-ray tube having an anode, a cathode, and a rotation driving unit that rotationally drives the anode. The anode is rotated by the rotation driving unit and a voltage is applied between the anode and the cathode to generate X-rays to be irradiated to the subject. Further, the X-ray imaging apparatus includes a holding unit that holds the X-ray tube in a movable manner, a brake that restricts movement of the X-ray tube by the holding unit, and a movement permission unit that releases restriction on movement of the X-ray tube by the brake. It has. The movement permission unit permits release of the brake when the rotation speed of the anode is lower than a predetermined value.

  The X-ray imaging apparatus according to the first embodiment of the present invention will be specifically described below with reference to FIGS.

  FIG. 1 is an explanatory diagram showing the overall configuration of the X-ray imaging apparatus of the present embodiment, and FIG. 2 is an explanatory diagram showing the configuration of the X-ray tube 6. FIG. 3 is a front view of the operation unit 4, and FIG. 4 is a functional block diagram of the holding device 2.

  As shown in FIG. 1, the X-ray imaging apparatus includes an imaging table 9, an X-ray tube apparatus 3, a holding device 2 that holds the X-ray tube apparatus 3 while being suspended from the ceiling, and an operation unit of the X-ray tube apparatus 3. 4, an aperture device 5, an X-ray high voltage generator 1, an X-ray detector 10, an image processor 11, an image storage unit 12, and an image display unit 13.

  The X-ray tube device 3 has a configuration in which the X-ray tube 6 having the structure shown in FIG. The apparatus housing 24 is provided with an X-ray emission opening. As shown in FIG. 2, the X-ray tube 6 includes an anode (target) 15, a cathode (filament) 17, a rotary bearing 16 that rotatably supports a shaft 23 of the anode 15, and an X-ray tube container that houses them. 18, a rotation drive unit 44 that rotationally drives the shaft 23, and an anode rotation number detection unit 52 that detects the rotation number of the anode 15. The rotation drive unit rotates the shaft 23 of the anode 15 at high speed during X-ray irradiation, and does not perform rotation drive after X-ray irradiation. After the end of the X-ray irradiation, the anode 15 and its shaft 23 continue to rotate due to inertia and stop after the rotational speed gradually decreases. The anode rotation number detector 52 detects the rotation number of the anode 15. Further, the X-ray tube device 3 may be provided with an X-ray filter that selectively transmits X-rays having specific energy.

  Although only the state where the imaging stand 9 supports the subject 8 in the supine position is shown in FIG. 1, the subject 9 can support the subject in a desired orientation such as standing or slanting in addition to the supine position.

  The holding device 2 includes a rail 21 in the front-rear direction and the left-right direction attached to a fixed portion such as a ceiling, a main body 25 movable along the rail 21 in the front-rear direction and the left-right direction, a vertical telescopic arm 26, and a swivel arm 27. And a rotating arm 28. The vertical telescopic arm 26 is an arm having a structure that can be expanded and contracted in the vertical direction along the axis 20, and its upper end is fixed to the lower portion of the main body 25. The swivel arm 27 is an arm whose axial direction is directed horizontally. One end of the swivel arm 27 is attached to the lower end of the vertical arm 26 and can swivel about the shaft 20 of the vertical telescopic arm 26. A rotating arm 28 is attached to the tip of the turning arm 27. The rotary arm 28 can rotate around an axis 14 parallel to the axis of the swivel arm 27. Thereby, the holding | maintenance apparatus 2 can move to each direction of back and forth, right and left, up and down, turning, and rotation.

  Although not shown in FIG. 1, the holding device 2 includes a brake 43 such as a disc brake for stopping movement in the front and rear, left and right, up and down, turning and rotation directions, and operations of these brakes 43. Are controlled (on / off (braking / releasing)) a brake control unit 42 (FIG. 4). The brake control unit 42 controls the operation of the drive unit of the brake 43 such as a disc brake, and controls on / off of the brake. In order to prevent the X-ray tube device 3 from moving in each direction due to its own weight or the like during imaging, the brake 43 in each direction is in an on (braking) state in a normal state.

  Further, as shown in FIG. 4, the holding device 2 includes detection units 45 to 49 for detecting the speed (or the number of rotations) of the X-ray tube device 3 in the front-rear, left-right, up-down, turn, and rotation directions. And a movement permitting unit 50 that outputs a signal permitting the brake control unit to release the brake to the brake control unit 42. For example, the holding device 2 has a calculation unit and a storage unit, and functions as the movement permission unit 50 when the calculation unit reads and executes a program stored in advance in the storage unit.

  The X-ray high voltage generator 1 supplies power to the X-ray tube device 3. Further, in the X-ray high voltage generator 1, as shown in FIG. 1, the values of the tube voltage and the tube current supplied from the X-ray high voltage generator 1 to the X-ray tube 6, and the rotation drive unit of the anode 15 An X-ray tube control unit 51 that performs control and the like is disposed.

  The operation unit 4 is attached to the front surface of the apparatus housing 24. As shown in FIG. 3, the operation unit 4 is gripped by an operator and manually moves the X-ray tube device 3 in the front and rear, left and right, up and down, swivel and rotation directions, and a plurality of brake release switches 32 to 38. And a display unit 39. Each of the plurality of brake release switches 32 to 38 receives a brake release operation from the operator. The plurality of brake release switches 32 to 38 are assigned so as to release a brake in one of the moving directions of the holding device 2 or to release two or more simultaneously. When the operator depresses any one of the brake release switches 32 to 38, the brake in the movement direction assigned to the brake release switch 32 to 38 is provided on the condition that the movement permission signal is output from the movement permission unit 50. 43 is released by the brake control unit 42. Therefore, the operator can grasp the handle 31 and manually move the X-ray tube device 3 in the direction in which the brake is released. Accordingly, the X-ray emission opening of the X-ray tube apparatus 3 is moved to a position facing the subject 8 according to the position and orientation of the subject 8 mounted on the imaging table 9 and directed toward the subject 8. be able to.

  The diaphragm device 5 limits the irradiation range of the X-rays generated by the X-ray tube device 3. Specifically, the diaphragm 5 has a plurality of X-ray shielding lead plates that shield X-rays generated from the X-ray tube device 3, and each of the plurality of X-ray shielding lead plates moves, An X-ray irradiation area for the specimen 8 is determined.

  The X-ray detection unit 10 is disposed at a position facing the X-ray tube device 3 with the subject 8 interposed therebetween (lower part of the imaging table 9), and detects X-rays transmitted through the subject 8. Specifically, for example, the X-ray detection unit 10 can be configured by arranging a plurality of detection elements for detecting X-rays in a two-dimensional array, and each detection element is irradiated from the X-ray tube device 3. The X-ray signal corresponding to the incident amount of the X-ray transmitted through the subject 8 is output. The X-ray detection unit 10 may be a combination of a photosensitive plate that emits light when irradiated with X-rays and a film that is exposed in accordance with its brightness.

  The image processing unit 11 performs image reconstruction processing and image processing on the X-ray signal output from the X-ray detection unit 10 to generate an X-ray image. Image processing can perform gamma conversion, gradation conversion processing, image enlargement / reduction, and the like. The image storage unit 12 stores the X-ray image (including the fluoroscopic image) output from the image processing unit 11. The image display unit 13 displays an X-ray image (including a fluoroscopic image) output from the image processing unit 11 or an X-ray image stored in the image storage unit 12.

  Next, the operation of the movement permission unit 50 will be described with reference to FIGS.

  As shown in FIG. 5, the anode 15 of the X-ray tube apparatus 3 is rotationally driven at a predetermined rotational speed during imaging, and rotates by inertia after imaging, and the rotational speed gradually decreases and stops. For this reason, when the X-ray tube apparatus 3 is manually moved in one or more directions of front and rear, left and right, up and down, swivel, and rotation in order to perform imaging at another position and orientation after imaging, the anode 15 is inertial. When rotating at a high speed, the Coriolis force acts in a direction perpendicular to the shaft 23 of the anode 15 due to the gyro effect, and the shaft 23 is pressed against the rotating bearing 16 and may be worn.

  Therefore, in the present embodiment, the movement permission unit 50 operates as in the flow of FIG. 6 and outputs a movement permission signal to the brake control unit 42. The brake control unit 42 releases the brake 43 when the brake release switches 32 to 38 are turned on and the movement permission signal is received from the movement permission 50 unit. Thereby, the X-ray tube apparatus 3 can be moved only during the period when the movement permission signal is output.

  Specifically, as shown in FIG. 6, the movement permission unit 50 determines whether the X-ray tube 6 is irradiating X-rays by detecting the operation of the X-ray tube control unit 51 (step 61). If X-ray irradiation is being performed, a signal for permitting movement of the X-ray tube device 3 (movement permission signal) is turned off, and the process returns to step 61 (step 62). In step 61, when the X-ray is not being irradiated, the anode rotation number is received from the anode rotation number detection unit 52 in the X-ray tube apparatus 3 (step 63), and the anode rotation number is smaller than a predetermined value. , The movement permission signal is output, and the process returns to step 61 (steps 64 and 65). On the other hand, if the anode rotation speed is equal to or greater than a predetermined value, the movement permission signal is turned off and the process returns to step 61 (steps 64 and 66).

  As described above, the movement permission unit 50 does not output a movement permission signal during X-ray irradiation or when the anode rotation speed is equal to or greater than a predetermined value. If the anode rotation speed becomes smaller than a predetermined value after the end of X-ray irradiation, a movement permission signal is output.

  The brake control unit 42 is turned on when the movement permission signal received from the movement permission unit 50 is on and any one of the plurality of brake release switches 32 to 38 is turned on by the operator. The brake 43 in the moving direction assigned to 32-38 is released. Therefore, during a period in which the movement permission signal from the movement permission unit 50 is off, even if the operator turns on the brake release switches 32 to 38, the brake 43 is not released. It cannot be moved.

  As a result, the shaft 23 of the anode 15 of the X-ray tube 6 can be prevented from being pressed against the rotary bearing 16 due to the gyro effect and worn, and the life of the X-ray tube 6 can be extended.

  FIG. 5 shows the relationship between the movement permission signal and the anode rotation speed when the value of the predetermined anode rotation speed used in step 64 is set to substantially zero, so that the anode rotation is substantially stopped. However, the present invention is not limited to this example. When the anode rotation speed has decreased to a predetermined value higher than zero, the movement permission signal is turned on. Can be configured to turn on.

  Moreover, the movement permission part 50 can also display the operator informing that the movement of the X-ray tube device 3 is not permitted when the release of the brake is not permitted. Specifically, when the movement permission signal is turned off in step 62 and step 66, a message notifying the operator that the X-ray tube device 3 cannot be moved is displayed on the display unit 39 of the operation unit 4. Can be displayed. The operator can grasp that the user cannot move by looking at this display.

(Second Embodiment)
In this invention, when the rotation speed of an anode is lower than a predetermined value, it can also comprise so that cancellation | release of a brake may be permitted intermittently. This will be described as a second embodiment with reference to FIG. Specifically, the configuration of the X-ray imaging apparatus of the second embodiment is the same as that of the X-ray imaging apparatus of the first embodiment, but part of the operation of the movement permission unit 50 is the first implementation. Different from form.

  In the second embodiment, in the operation flow of the movement permission unit 50 of FIG. 6, when the anode rotation speed is lower than the predetermined value P in step 64 and higher than zero, the movement permission signal is determined in step 65. Is output intermittently. That is, ON / OFF is repeated for a certain time. If the anode rotation speed becomes zero in step 64, the movement permission signal is continuously turned on in step 65. The other steps 61 to 63 and 66 are the same as those in the first embodiment, and thus description thereof is omitted.

  If the operator turns on any of the brake release switches 32 to 38 of the operation unit 4 during the period in which the movement permission signal is intermittently turned on, the brake control unit 42 moves in the direction corresponding to the switch. Release the brake 43. Thus, the operator can move the X-ray tube device 3 only during a period in which the movement permission signal is intermittently turned on. That is, the operator can move the X-ray tube device 3 intermittently during the period in which the anode 15 is rotating by inertia.

  In this configuration, since the time during which the X-ray tube apparatus 3 can be moved during the period in which the anode 15 is inertial and rotating is intermittent in a short time, the moving speed of the X-ray tube apparatus 3 is suppressed, and the anode Coriolis force acting on the 15 shafts 23 can be suppressed. Therefore, the X-ray tube apparatus 3 can be intermittently moved while preventing the shaft 23 from being worn, and the convenience for the operator is improved.

  Since the movement permission signal is continuously turned on after the anode 15 is stopped, the X-ray tube device 3 can be continuously moved.

  Further, in the second embodiment, when the movement permission signal is intermittently turned on in step 65, it is operated that the X-ray tube apparatus 3 can be moved intermittently on the display unit 39 of the operation unit 4. A message to inform the user can be displayed. The operator can grasp that it is in a state where it can move intermittently little by little by looking at this display.

  Other configurations are the same as those of the first embodiment, and thus description thereof is omitted.

(Third embodiment)
In the present invention, the time for intermittently permitting the release of the brake can be made longer as the rotational speed of the anode is lower. This will be described as a third embodiment with reference to FIG.

  In the X-ray imaging apparatus of the third embodiment, similarly to the second embodiment, the movement permission unit 50 permits the movement when the anode rotation speed is lower than the predetermined value P and higher than zero. Although the signal is intermittently output, the third embodiment is different from the second embodiment in that the intermittent cycle is changed according to the anode rotation speed.

  That is, as shown in FIG. 8, when the anode rotation speed is lower than the predetermined value P and higher than zero in step 64 of FIG. 6, the anode rotation speed value is relatively increased within this range. For example, the time for which the movement permission signal is intermittently turned on is shortened. If the value of the anode rotation number is relatively low, the time for which the movement permission signal is intermittently turned on is lengthened. To achieve this, if the anode rotation speed is lower than the predetermined value P and higher than zero in step 64, a predetermined on-time is set in step 65 according to the value of the anode rotation speed. Then, the movement permission signal is turned on only for the set time. When the set time has elapsed, the movement permission signal is turned off, and the process returns to step 61. The ON time set in step 65 is determined in advance so as to become longer if the anode rotation speed is low.

  Thus, by changing the time during which the movement permission signal is intermittently turned on according to the number of anode rotations, the operator intermittently operates the X-ray tube device 3 during the period in which the anode 15 rotates by inertia. The time that can be moved automatically increases as the anode rotation speed decreases. Since the movement permission signal is continuously turned on after the anode 15 is stopped, the X-ray tube apparatus 3 can be moved at a desired speed.

  As described above, since the Coriolis force increases as the anode rotational speed increases by changing the intermittent ON time according to the anode rotational speed, the Coriolis force acting on the shaft 23 of the anode 15 is suppressed, and the shaft 23 The travel time of the X-ray tube device 3 can be set while preventing wear, and the convenience for the operator is further improved.

  Other configurations are the same as those of the first embodiment, and thus description thereof is omitted.

(Fourth embodiment)
The present invention uses a brake having a structure capable of changing the brake release degree continuously or stepwise, and when the anode rotation speed is lower than a predetermined value, the brake release degree is increased as the anode rotation speed is lower. It is also possible. This will be described as a fourth embodiment with reference to FIG.

  In the fourth embodiment, the movement permission signal output from the movement permission section 50 is not simply on / off, and the signal strength can be adjusted continuously or in multiple stages. The movement permission signal may be an analog signal, or may be configured to output magnitude information of the movement permission signal as a digital signal. The brake control unit 42 changes the degree of brake release according to the strength of the movement permission signal of the movement permission unit 50. That is, the degree of release of the brake 43 is increased if the intensity of the movement permission signal is large, and the degree of release of the brake 43 is decreased if the intensity of the movement permission signal is small. For example, when the brake 43 is a disc brake, the voltage supplied to the disc brake is changed to adjust the degree of pressing (releasing degree) of the disc brake against the moving shaft (rail or the like).

  In such a configuration, in the fourth embodiment, as illustrated in FIG. 9, the movement permission unit 50 causes the anode rotation speed to be lower than the predetermined value P and equal to or greater than zero in Step 64 of FIG. 6. In the range, when the anode rotation speed is relatively high, the intensity of the movement permission signal is reduced, and when the anode rotation speed is relatively low, the movement permission signal is increased in intensity. When the anode rotation speed is zero in step 64, the movement permission signal is maximized.

  When a movement permission signal is output and any one of the brake release switches 32 to 38 is pressed, the brake control unit 42 moves in the direction assigned to the pressed brake release switch 32 to 38. Release the brake 43. At this time, the release degree of the brake 43 is reduced if the strength of the movement permission signal is small, and the release degree is increased if the strength is high.

  Thus, since the degree of release of the brake 43 is small if the anode rotation speed is lower than the predetermined value P and the anode rotation speed is relatively high within a range of zero or more, the operator releases the X-ray tube device. If you try to move 3, you can move little by little slowly. On the other hand, if the anode rotation speed is relatively low, the degree of release of the brake 43 increases, so that the operator and the X-ray tube device 3 can be moved relatively freely. When the anode rotation speed becomes zero, the X-ray tube device 3 can be moved freely.

  In this embodiment, since the degree of brake release can be continuously changed according to the number of anode rotations, the operability of the operator can be improved while suppressing the Coriolis force and preventing the shaft 23 from being worn. it can.

  Other configurations are the same as those of the first embodiment, and thus description thereof is omitted.

(Fifth embodiment)
In the present invention, when the release of the brake is permitted, the moving speed of the X-ray tube device is detected, and when the detected moving speed is equal to or higher than a predetermined value, the permission may be canceled. This will be described as a fifth embodiment with reference to FIG.

  In the fifth embodiment, as shown in FIG. 10, when the anode rotation speed is lower than a predetermined value P and higher than zero, as in steps 61 to 66 in FIG. 6 of the second embodiment. Outputs a movement permission signal intermittently in step 65. During the short period when the movement permission signal is intermittently turned on, the operator can move the X-ray tube apparatus as described in the second embodiment. However, since this period is a period in which the anode 15 is inertial and rotating, when the operator moves the X-ray tube apparatus 3 at a high speed during a period when the movement permission signal is short, a large Coriolis force is required. Acts on the shaft 23 of the anode 15. Therefore, in the fifth embodiment, the movement permission unit 50 performs steps 67 to 70 as shown in FIG. 10 after step 65 so that the operator does not move the X-ray tube apparatus 3 at a high speed.

  Specifically, if the movement permission unit 50 intermittently turns on the movement permission signal in step 65, the brake control unit 42 determines whether the brake control unit 42 has released the brake 43 in any movement direction. Is detected from the output signal (step 67). When released, the speed (or the number of rotations) of movement in the front-rear, left-right, up-down, swivel, and rotation directions of the X-ray tube device 3 is detected from the detection units 45 to 49 provided in the holding device 2. If the moving speed in any direction is equal to or higher than the speed set in advance in that direction, the movement permission signal is turned off and the process returns to step 61 (steps 68 to 70). On the other hand, if the moving speed of the X-ray tube apparatus 3 is less than the preset speed at step 69, the process returns to step 61.

  As described above, in the fifth embodiment, when the anode is coasting and the movement permission signal is intermittently turned on while rotating, the X-ray tube apparatus 3 can be moved little by little for a short time. When the X-ray tube apparatus 3 is moved suddenly at a high speed during this period, the movement permission signal is turned off. When the movement permission signal is turned off, the brake control unit 42 applies the brake 43, so that the rapid movement of the X-ray tube device 3 can be stopped. That is, the period in which the power is intermittently turned on is forcibly ended and turned off. Thereby, the Coriolis force which acts on the axis | shaft 23 of the anode 15 can be suppressed, and the abrasion by being pressed on the rotating bearing 16 can be prevented.

  In the present embodiment, when the movement permission signal is intermittently turned on in Step 65, a message prompting the operator to move the X-ray tube device 3 slowly on the display unit 39 of the operation unit 4 or a sudden A message notifying the operator that the X-ray tube device 3 cannot be moved may be displayed.

  In addition, when the moving direction of the X-ray tube apparatus 3 coincides with the direction of the axis 23 of the anode 15, no Coriolis force is generated. Therefore, in step 68, the X-ray tube apparatus 3 detected by the detection units 45 to 49 is detected. It is also possible to determine whether or not the moving direction of the X-ray tube device 3 coincides with the direction of the shaft 23 from the speed (or the number of rotations) of the front and rear, left and right, up and down, turning and rotational directions. When the moving direction matches the direction of the shaft 23, no Coriolis force is generated. Therefore, the movement permission signal may not be turned off in step 70, and the process may return to step 61.

  In step 65 of FIG. 10, the operation of turning on the movement permission signal intermittently may be an operation of turning on / off alternately at a constant time as shown in FIG. 7, or the anode rotation speed as shown in FIG. It may be an operation of adjusting the time for which the power is intermittently turned on according to the above. Further, in the case where the movement is permitted when it is not intermittently turned on / off in step 65 and is lower than a predetermined anode rotation number as shown in FIG. 6, steps 67 to 70 in FIG. 10 may be performed. Also in this case, since the rapid movement of the X-ray tube device 3 while the anode is rotating can be stopped, wear of the shaft 23 of the anode 15 can be prevented.

  Since other configurations are the same as those of the second embodiment, the description thereof is omitted.

(Sixth embodiment)
The present invention may be configured to detect the rotation speed of the anode as in the first to fifth embodiments, and to determine whether to permit the brake using the detected rotation speed. The determination may be made based on the elapsed time from the end of the X-ray irradiation of the tube. That is, in the first to fifth embodiments, after detecting the end of X-ray irradiation, the anode rotation speed is detected (steps 61 and 63), and a movement permission signal is output based on the rotation speed. The anode rotation speed due to inertia after the end of the line irradiation decreases almost every time while drawing the same downward curve. Therefore, in the sixth embodiment, the movement permission signal is turned on according to the elapsed time from the end of the X-ray irradiation without detecting the anode rotation speed. Specifically, the relationship between the elapsed time from the end of X-ray irradiation and the inertial anode rotation speed is obtained in advance, and the movement permission signal is turned on by the elapsed time at which the predetermined anode rotation speed is reached.

  For example, as shown in FIG. 11, the movement permission unit 50 performs step 164 instead of step 64 in FIG. In the flow of FIG. 11, when X-ray irradiation has been completed in Step 61, it is determined in Step 164 whether the elapsed time has reached a predetermined elapsed time from the end of X-ray irradiation. Proceeding to step 66, a movement permission signal is output. Thereby, since the movement permission signal is turned on at less than the anode rotation speed corresponding to the predetermined elapsed time, the same effect as in the first embodiment can be obtained.

  In addition, it is also possible to make it the operation | movement which turns on the intermittent movement permission signal of 2nd Embodiment and 3rd Embodiment by the elapsed time after completion | finish of X-ray irradiation. In this case, as shown in FIGS. 7 and 8, a plurality of timings for turning on / off the movement permission signal are determined in advance, and when the timing is reached, the movement permission signal is turned on / off.

  Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

(Seventh embodiment)
In the X-ray imaging apparatus of the seventh embodiment, unlike the first to sixth embodiments, the rotation drive unit 44 of the anode 15 does not stop the rotation drive even after X-ray irradiation (when not irradiated). Is continuously rotated at a constant speed until X-ray irradiation. In the X-ray imaging apparatus having such a configuration, since the anode 15 is always rotating, when the X-ray tube apparatus 3 is moved after X-ray irradiation, the shaft 23 is pressed against the rotary bearing 16 due to the Coriolis force and is worn. To do. Therefore, the movement permission unit intermittently permits the release of the brake when X-rays are not irradiated.

  Specifically, in the seventh embodiment, as shown in FIG. 12, during the period from the end of the X-ray irradiation to the next X-ray irradiation, the movement permission signal is intermittently input as in the sixth embodiment. Turn on and off. That is, a plurality of timings at which the movement permission signal is turned on / off according to the elapsed time after X-ray irradiation is determined in advance, and the movement permission signal is turned on / off when the elapsed time from the end of X-ray irradiation reaches that timing. This is continued until the next X-ray irradiation starts.

  As described above, in the X-ray imaging apparatus in which the anode 15 is continuously rotated at a constant speed even after the X-ray irradiation ends, the X-ray tube apparatus 3 is moved by intermittently turning the movement permission signal on and off after the X-ray irradiation ends. Since the possible time is short and intermittent, the moving speed of the X-ray tube apparatus 3 is suppressed. Therefore, the Coriolis force acting on the shaft 23 of the anode 15 is suppressed, and the effect that the wear of the shaft 23 can be prevented is obtained.

1: X-ray high voltage generator, 2: holding device, 3: X-ray tube device, 4: operation unit, 5: diaphragm device, 6: X-ray tube, 8: subject, 9: imaging table, 10: X Line detection unit, 11: Image processing unit, 12: Image storage unit, 13: Image display unit, 15: Anode (target), 16: Rotary bearing, 17: Cathode (filament), 18: X-ray tube container, 21: Rail: 23: Shaft, 25: Holding device body, 26: Vertical telescopic arm, 27: Swivel arm, 28: Rotating arm, 31: Handle, 32-38: Brake release switch, 39: Display unit, 42: Brake control unit 43: Brake, 45: Front-rear direction movement speed detection unit, 46: Left-right direction movement speed detection unit, 47: Up-down direction movement speed detection unit, 48: Turning direction movement (rotation) speed detection unit, 49 : Movement (rotation) speed detector in the rotation direction, 50: Dynamic authorization unit, 51: X-ray tube controller, 52: anode rotation speed detector

Claims (10)

An X-ray that has an anode, a cathode, and a rotation drive unit that rotationally drives the anode, and that irradiates the subject by rotating the anode by the rotation drive unit and applying a voltage between the anode and the cathode An X-ray tube that generates
A holding part for holding the X-ray tube in a movable manner;
A brake for restricting movement of the X-ray tube by the holding unit;
In an X-ray imaging apparatus comprising:
A movement permission unit for releasing restriction of movement of the X-ray tube by the brake;
The movement permitting unit permits the release of the brake when the rotation speed of the anode is lower than a predetermined value.   The X-ray imaging apparatus according to claim 1, wherein the movement permission unit intermittently permits the release of the brake when the rotation speed of the anode is lower than the predetermined value. Shooting device.   3. The X-ray imaging apparatus according to claim 2, wherein the movement permission unit extends a time for permitting the release of the brake intermittently as the number of rotations of the anode is lower. apparatus. The X-ray imaging apparatus according to claim 1, wherein the brake has a structure capable of changing a brake release degree continuously or stepwise.
The X-ray imaging apparatus according to claim 1, wherein when the rotation speed of the anode is lower than the predetermined value, the movement permission unit increases the degree of release of the brake as the rotation speed of the anode is lower.   2. The X-ray imaging apparatus according to claim 1, wherein the movement permission unit detects the rotation speed of the anode and determines permission to release the brake using the detected rotation speed. 3. X-ray equipment.   2. The X-ray imaging apparatus according to claim 1, wherein the movement permission unit determines whether the number of rotations of the anode is lower than the predetermined value based on an elapsed time from the end of the X-ray irradiation of the X-ray tube. An X-ray imaging apparatus characterized by: The X-ray imaging apparatus according to claim 1, further comprising: a brake control unit that controls the operation of the brake; and a brake release switch that receives a brake release operation from an operator;
The movement permission unit outputs a movement permission signal for permitting release of the brake to the brake control unit,
The X-ray imaging apparatus, wherein the brake control unit releases the brake when the brake release switch is turned on and a movement permission signal is received from the movement permission unit.   2. The X-ray imaging apparatus according to claim 1, wherein when the release of the brake is permitted, the movement permission unit detects a movement speed of the X-ray tube, and the detected movement speed is equal to or greater than a predetermined value. The X-ray imaging apparatus is characterized in that the permission is canceled. The X-ray imaging apparatus according to claim 1, further comprising a display unit,
The movement permission unit displays an indication on the display unit notifying the operator that movement of the X-ray tube is not permitted when release of the brake is not permitted. . An anode, a cathode, and a rotation drive unit that continuously rotates the anode during X-ray irradiation and non-irradiation, and applies X-rays to the subject by applying a voltage between the anode and the cathode. An X-ray tube to be generated;
A holding part for holding the X-ray tube in a movable manner;
A brake for restricting movement of the X-ray tube by the holding unit;
In an X-ray imaging apparatus comprising:
A movement permission unit for releasing restriction of movement of the X-ray tube by the brake;
The movement permission unit intermittently permits the release of the brake when the X-ray is not irradiated.

Images