JPS6361019B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an X-ray tomography apparatus.

As is well known, in this type of apparatus, a rotational center is set within a plane containing a target tomographic plane of a subject, and an X-ray tube rotates around the rotational center to perform tomography. In this case, it is necessary to make the height of the tomographic plane visible prior to imaging. Conventionally, a pointer is placed on the center of rotation, and the pointer is extended close to the surface of the subject to indicate the tomographic plane, but with this, there is a risk that the tip of the pointer may touch the subject. This is extremely dangerous, and if you place it far away from the subject to avoid this, it will be difficult to read the position of the tomographic plane.

It has also been considered to use light instead of a pointer, in which light from a projector is projected onto the subject and the projected position can be visually observed using a reflector. According to this, there is no danger to the subject such as the pointer, and there is no danger to the subject, and
Even when the operator stands on the opposite side to the installation side of the tube rotation mechanism, the projector, the reflector, etc., there is an advantage in that the reflector can be visually recognized across the subject. However, with this configuration, the reflecting mirror cannot be installed on the rotation center, so the only option is to install it at a location away from the rotation center, and as a result, the image reflected on the reflecting mirror becomes oblique and difficult to see. Furthermore, since light is used, the projection point, that is, the height of the tomographic plane cannot be read on a scale.

The purpose of this invention is to enable the position of a fault plane to be visually confirmed safely and accurately.

Embodiments of the invention will be described with reference to the drawings. 1 is the table, 2 is the subject, 3 is the swinging rack, 4 is the X-ray tube, 5 is the film, 6 is the rotation center axis of the swinging rack 3, and 7 is fixed with a setting device that sets the height of the tomographic plane. A screw shaft 9 supported perpendicularly to a frame 8 is rotated by a motor 10, and a slider 11 screwed into the screw shaft 9 is raised and lowered by this rotation. As the slider 11 moves up and down, the rotation center shaft 6 also moves up and down along the swing ring 3, thereby increasing the rotation center of the swing ring 3 and the height of the fault plane. can be set freely. The rocking ring 3 is rocked by a drive source (not shown) in a plane perpendicular to the paper surface. These configurations are not much different from normal ones of this type.

According to this invention, a projector 13 that moves up and down together with the rotation center shaft 6 is installed. The light projector 13 accommodates a light source (not shown), a condensing lens, and a cross-shaped slit for making the light projected onto the subject 2 into a cross-shaped light, as will be described later. In the illustrated example, the projector 13 is arranged vertically, so that the light emitted from it is refracted by the reflecting mirror 14 and then projected onto the side surface of the subject 2. The direction of projection from the reflecting mirror 14 is perpendicular to the direction of projection of X-rays from the X-ray tube 4. The light projected onto the subject 2 is a horizontal light 15 and a vertical light 16 as shown in FIG.
The intersection point 17 is set at a position coinciding with the axis of the rotation center axis 6, and the horizontal light is set within a horizontal plane containing the rotation center axis 6. Therefore, when the projection light as shown in FIG.
The projection location coincides with the tomographic plane to be imaged. A pointer 18 that moves up and down together with another rotation center shaft 6 is installed as required.

On the path of the projected light from the reflecting mirror 14, a reflecting mirror 19 as shown in FIG. 3 is fixed to a fixed frame or the like (not shown). This reflecting mirror 19 is for projecting the light projected onto the subject 2 as described above.
An operator standing on the opposite side of the reflecting mirror 19 can visually recognize the position of the light projected onto the subject 2. The reflector 19 is located at a position that blocks the light from the reflector 14 toward the subject 2, and in order to avoid this glare, the reflector 19 has a long window 20 extending in the height direction.
is formed. The long window 20 may be fitted with glass or other transparent material, or may be a simple cutout hole. Since the light directed toward the subject 2 from the reflecting mirror 14 passes through this long window 20 as shown by the dotted line in the figure, the light will not be blocked even if the reflecting mirror 19 is installed between the reflecting mirror 14 and the subject 2. There isn't. This allows the reflecting mirror 19 to be installed at a position sufficiently close to the subject 2 without any hindrance.

A pointer 18 is placed in the long window 20, and the position of the pointer 18 can be read on a scale 21 provided at the periphery of the long window 20. As mentioned above, since the pointer 18 moves up and down together with the rotation center axis 6, by appropriately selecting the position of the scale 21 and therefore the position of the reflecting mirror 19, the indicated value on the scale 21 of the pointer 18 can be adjusted to the reference value. It can be displayed as a height value from a surface (for example, the surface of table 1). For example, when the rotation center axis 6 is at the same height as the surface of the table 1, if you set the pointer 18 so that it points to the zero value on the scale 21, then the rotation center axis 6 can be raised to any position. Even if
The value indicated on the scale 21 by the pointer 18 is the height value from the surface of the table 1.

In the above configuration, when the motor 10 is driven to set the height of the tomographic plane, the rotation center shaft 6 and the light projector 13 are moved up and down in unison, thereby also raising and lowering the light projection position onto the subject 2. . However, the intersection point of the projected light always coincides with the axis of the rotation center axis 6, and the horizontal light 15 coincides with the tomographic plane to be photographed. becomes possible. Since this light projection state is projected onto the reflecting mirror 19, an operator standing on the opposite side of the subject 2 can easily see it visually.
In this case, since the reflecting mirror 19 is located close to the subject 2, the image projected onto the reflecting mirror 19 will not be oblique, and therefore the tomographic region and the center of rotation can be seen accurately. and is extremely easy to see.

As described in detail above, according to the present invention, there is no need to set up a pointer close to the subject as in the past to confirm the height position of the tomographic plane, so there is no danger to the subject, and there is no light Even when using this method, the effect is that the image does not become oblique and difficult to see as in the case of the conventional method.

[Brief explanation of drawings]

Figure 1 is a front view showing an embodiment of the invention, Figure 2 is a front view showing an embodiment of the invention.
The figure is a front view showing the light projection surface, and FIG. 3 is a front view of the reflecting mirror. 2...Subject, 3...Swivel, 4...X-ray tube, 6...Rotation center axis, 13...Floodlight, 15...
...Horizontal light, 16...Vertical light, 17...Intersection, 18
...Pointer, 19...Reflector, ...20...Long window, 2
1...Scale.

Claims (1)

[Claims] 1. A projector is provided that moves up and down integrally with the center axis of rotation of the X-ray tube, and from the projector, horizontal light whose intersection point coincides with the axis of the center axis of rotation and is within a horizontal plane that includes the center axis; A cross-shaped light consisting of a vertical light perpendicular to a horizontal light is projected, and a long window is provided on the path of the projected light from the projector through which the projected light passes, and a long window is provided to prevent the reflection of the projected light. An X-ray tomography apparatus comprising: a reflecting mirror for visually recognizing an image; and a scale for reading the height of the rotation center axis from a reference plane on the periphery of the long window.