JPH0586219B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an X-ray multi-orbit tomography apparatus equipped with a grid rotation transmission mechanism that rotates a grid in synchronization with the movement of an X-ray tube. An X-ray multi-orbit tomography device equipped with a highly rigid, expandable and low-cost grid rotation transmission mechanism, which transmits the rotation of the X-ray tube to the grid without phase shift to obtain high-quality X-ray images. Regarding.

[Technical background of the invention]

An X-ray tomography device moves an X-ray tube along a certain trajectory in order to obtain a targeted tomographic image of the inside of a subject. , so that the relative velocity between the projection of an arbitrary point on a plane of the subject onto the film surface and the film becomes zero.

Among such X-ray tomography devices, in the so-called X-ray multi-orbit tomography device in which the X-ray tube moves in multiple orbits, the X-ray tube is moved in a plane parallel to the plane containing the subject's body axis. Generally, the object is moved along a trajectory such as a straight line, circle, or spiral.

By the way, in X-ray photography, only the primary X-rays that have passed through the subject are allowed to reach the film;
In order to prevent secondary X-rays, that is, scattered rays having different directions from the lines, from reaching the film, a configuration using a grid made of thin metal foils arranged in parallel is used. For example, in the case of a circular orbit, a grid rotation transmission mechanism is applied that moves the grid in synchronization with the circular orbit of the X-ray tube.

FIG. 4 is a schematic diagram of an X-ray multi-orbit tomography apparatus equipped with a conventional grid rotation transmission mechanism. The butt key device 3, which is disposed at the same time, is rotatably provided with a grid 4.

The grid rotation transmission mechanism also includes a first shaft 5 on the X-ray tube side and a second shaft on the X-ray tube side as a rotation transmission system for the X-ray tube 1.
A first shaft 7 on the grid side and a second shaft 8 on the grid side are provided as a rotation transmission system for the grid 4. The second shaft 6 on the X-ray tube side and the second shaft 8 on the grid side are connected by a flexible wire 9. are connected by.

[Problems with background technology]

With the above configuration, the rotation of the X-ray tube 1 is transmitted from the first shaft 5 on the X-ray tube side and the second shaft 6 on the X-ray tube side to the flexible wire 9, and the rotation of the flexible wire 9 is transmitted to the first shaft on the grid side. It becomes possible to transmit the signal to the grid 4 via the grid-side second shaft 8.

However, since the X-ray tube rotation transmission system and the grid rotation transmission system are configured to transmit rotation using a flexible wire 9 with low torsional rigidity, it is impossible to transmit the rotation of the X-ray tube 1 without phase shift. Have difficulty. In this case, if a phase shift occurs, it will lead to poor image quality due to insufficient dose, and good X-ray diagnosis will not be possible. Although it is conceivable to use a spline shaft instead of the flexible wire 9 as a method that does not cause a phase shift, this increases the cost and is not practical, which is a problem when applied to this type of mechanism.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
The object is to provide an X-ray multi-orbit tomography apparatus that is equipped with a grid rotation transmission mechanism that has high torsional rigidity, is expandable and retractable, and is low in cost, and that can obtain high-quality images while preventing phase shifts.

[Summary of the invention]

In order to achieve such an object, the present invention provides an X-ray multi-orbit tomography apparatus equipped with a grid rotation transmission mechanism that rotates a grid in synchronization with the movement of an X-ray tube. a hollow cylinder connected to move in synchronization with the X-ray tube and having a pair of axially opposed grooves formed therein; one end connected to rotate the grid and the other end to the other end of the hollow cylinder; The present invention is characterized by comprising a shaft inserted into the hollow cylinder, and a pin formed to span the pair of grooves at right angles to the shaft to prevent mutual rotation of the shaft and the hollow cylinder.

[Embodiments of the invention]

An embodiment of the X-ray multi-orbit tomography apparatus according to the present invention will be described below with reference to the drawings. Figure 1 a, b
1 shows the X-ray multi-orbit tomography apparatus of this embodiment, FIG. 1a is a front view, and FIG. 1b is a side view.

In FIG. 1, reference numerals 11 and 12 are stands fixed to the floor, and the stand 11 is provided with an x-direction guide rail 13 that guides the movement of a butt key device 18 and a movable housing 15 in the x-direction, which will be described later. The bearing 1 is attached to this x-direction guide rail 13.
4, one end side of a movable housing 15 that moves in the x direction in the drawing is supported. The pedestal 12 has a substantially U-shape, and an x-direction guide rail 13 is provided in the middle thereof to guide the movement of a butt key device 18 and a movable housing 15, which will be described later, in the x-direction shown in the figure. The movable housing 15 moves in the x direction shown in the figure via the bearing 14.
The other end is supported.

Y-direction guide rails 16 are provided on both sides of the movable housing 15 to guide the movement of a butt key device 18 (to be described later) in the y-direction shown on the movable housing 15.
A butt key device 18 having an X-ray film storage section therein is supported via 7. Moreover, the rotation center point 1
A grid 20 is provided which is pivotally supported at 9 and rotates in the direction of the arrow shown in the figure, a gear is formed around the circumference of this grid 20, and a chain 22 is stretched between this gear and a separately installed gear 21. The rotation of the gear 21 is transmitted to the grid 20.

This gear 21 is rotatably connected to a grid rotation transmission mechanism 23, which is a main part of this embodiment for interlocking movement with an X-ray tube 29, which will be described later. Further, one end of a connecting arm 24 constituted by a link mechanism is engaged with the butkey device 18, and the intermediate portion of this connecting arm 24 is semi-fixed at a mounting surface setting portion 25 in the intermediate portion of the pedestal 12. A rotation center is set, and an X-ray tube 29, which will be described later, is connected to the other end.
It rotates in a conical shape as a whole, and the rotation of the X-ray tube 29 is transmitted to the Butsky device 18.

On the other hand, a gear 26 is provided at the top of the pedestal 12 and is driven by a motor (not shown) to rotate as shown by the arrow in the figure.A gear 28 is also provided which is rotated by a chain 27 that is stretched around the gear 26. It is connected to the other end of the grid rotation transmission mechanism 23.

Further, a rotating body 28 is provided at the lower end of the shaft of the gear 26, and an X-ray tube 29 is provided on this rotating body 28 so as to be movable in the z-direction shown in the figure, and is connected to the rotating body 28 so as to be movable in the z-direction shown in the figure. The other end of the arm 23 is connected.

With the above configuration, the X-ray tube 29 is rotated in a predetermined manner via the gear 26 which is rotationally driven by a motor (not shown), and the rotation is transmitted to the Butsky device 18 by the connecting arm 24, and the X-ray tube 29 is rotated in the x direction and the y direction. A synthetic motion of is realized. At this time, gear 26
The rotation is transmitted to the transmission mechanism 23 via the chain 27 and gear 28, and drives the grid 20 to rotate about the rotation center point 19.

The above is an overview of the operation of the apparatus of this embodiment. Next, the grid rotation transmission mechanism 23, which is the main part of this embodiment, will be explained with reference to FIG. Figures 2a and 2b show the main parts of the grid rotation transmission mechanism 23 in this embodiment, that is, the configuration of the transmission mechanism that connects the X-ray tube rotation transmission system and the grid rotation transmission system. FIG. 2b is a perspective view showing the extended state.

In the transmission mechanism 23 shown in FIG. 2, 40 is a hollow cylinder whose one end is connected to move in synchronization with the X-ray tube, and in which a pair of grooves 40a ₁ and 40a ₂ are formed facing each other in the axial direction. One end is connected to rotate the grid and the other end is a hollow cylinder 4
0 is the shaft inserted into the other end side, and 42 is the shaft 41
This is a pin that is formed across the pair of grooves 40a ₁ and 40a ₂ at right angles to the shaft 41 in order to prevent mutual rotation between the shaft 41 and the hollow cylinder 40. With this structure, the shaft 41 is As shown in b, it is movable telescopically on the hollow cylinder 40.

Next, the operation of the above configuration will be explained with reference to FIG. FIG. 3 is a schematic diagram showing an X-ray multi-orbit tomography apparatus using the transmission mechanism 23 of FIG. 2, in which the same parts as in FIG. 4 are given the same reference numerals.

As shown in FIG. 3, the rotation of the X-ray tube 1 is transmitted from the first shaft 5 on the X-ray tube side and the second shaft 6 on the X-ray tube side to the transmission mechanism 23 of this embodiment, so that the rotation of the Rotate the cylinder 40. The rotation of the hollow cylinder 40 is transmitted to the shaft 41, which is prevented from rotating by the pin 42, and drives the shaft 41 to rotate. This rotational drive of the shaft 41 rotates the grid 4 via the first grid-side shaft 7 and the second grid-side shaft 8.

As described above, according to this embodiment, the X-ray tube rotation transmission system and the grid rotation transmission system are connected to the hollow cylinder 4.
0. Since the rotation is transmitted using the transmission mechanism 23 which is composed of a shaft 41 and a pin 42 and has high rigidity,
The rotation of the X-ray tube 1 can be transmitted without phase shift, high-quality images can be obtained without causing insufficient radiation, and good X-ray diagnosis can be performed.

Further, the transmission mechanism 23 is a grooved hollow cylinder 4
0, a shaft 41, and a pin 42, and can be manufactured at low cost.

〔Effect of the invention〕

As detailed above, according to the present invention, the grid rotation transmission mechanism includes a hollow cylinder whose one end is connected to move in synchronization with the X-ray tube and in which a pair of grooves are formed facing each other in the axial direction; A shaft connected to rotate the grid and having its other end inserted into the other end of the hollow cylinder, and a pair of grooves perpendicular to the shaft to prevent mutual rotation between the shaft and the hollow cylinder. The grid rotation transmission mechanism has high rigidity, is expandable and contractable, and is low in cost. This is something that a photographic device can provide.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the X-ray multi-orbit tomography apparatus according to the present invention, FIG. 2 is a perspective view showing a transmission mechanism which is the main part of the embodiment, and FIG. FIG. 4 is a schematic diagram showing an X-ray multi-orbit tomography apparatus using a transmission mechanism, and FIG. 4 is a schematic diagram showing a conventional example. 1...X-ray tube, 2...Arm, 3...Butsky device, 4...Grid, 5...X-ray tube side first axis,
6...Second axis on the X-ray tube side, 7...First axis on the grid side
Shaft, 8... Grid side second shaft, 23... Transmission mechanism, 40... Hollow cylinder, 40a ₁ , 40a ₂ ...
Groove, 41... shaft, 42... pin.

Claims (1)

[Claims] 1. In an X-ray multi-orbit tomography apparatus equipped with a grid rotation transmission mechanism that rotates the grid in synchronization with the movement of the X-ray tube, one end of the grid rotation transmission mechanism is connected to the X-ray tube for synchronous movement. a hollow cylinder in which a pair of grooves are formed facing each other in the axial direction; a shaft having one end connected to rotate the grid and the other end inserted into the other end of the hollow cylinder; 1. An X-ray multi-orbit tomography apparatus, comprising: a pin extending between the pair of grooves at right angles to the axis to prevent mutual rotation with the hollow cylinder.