JPH0228637Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a stereo X-ray tube device for obtaining three-dimensional X-ray photographs, and particularly relates to an improvement of the gate for limiting the X-ray radiation range.

Generally, a stereo X-ray tube device includes an X-ray tube having a plurality of focal positions on an anode target, housed in a container called a Haube.

That is, the main parts of a commonly used stereo X-ray tube apparatus are constructed as shown in FIGS. 1a and 1b, and an X-ray tube 1 is housed in a container 2.
The X-ray tube 1 has a plurality of focal positions, for example two focal positions A and B, on an anode target 4 disposed within an envelope 3, and is set at a predetermined focal interval l. Corresponding to the focal positions A and B, the envelope 3 is provided with an X-ray emission window 5 made of Be. The inner surface of the container 2 that houses such an X-ray tube 1 is lined with a lead plate 6 to prevent unnecessary X-rays from being emitted outside the tube device, and the inner surface is lined with a lead plate 6.
An insulating and cooling medium such as insulating oil and gas is filled between the wire tube 1 and the wire tube 1 . Further, the container 2 is provided with a window called an X-ray emission port 7 for extracting necessary X-rays at a position opposite to the X-ray emission window 5 of the X-ray tube 1 . The X-ray emission port 7 is composed of an oil-tight sealing part 8, an O-ring 9, a member 10 for tightening and fixing these parts, an X-ray emission range limiting gate 11 made of lead, and a holding plate 12. In this case, the gate 11 is formed into a circular mortar shape, and has one circular through hole (opening) approximately the same size as the X-ray emission window 5 in the center. In addition, in the figure, 13
is the appropriate radiation range of X-rays emitted from focal position A, 14
is the appropriate radiation range of X-rays emitted from focal position B, 1
5 and 16 are the out-of-focus X-ray range from focal position A, 1
7 and 18 are out-of-focus X-ray ranges from focal position B.

By the way, when performing stereoscopic imaging using a stereo X-ray tube device having a plurality of focal positions A and B with a constant focal interval l as described above, it is necessary to remove out-of-focus X-rays and properly transmit X-rays at each focal point. It is necessary to separate them. Therefore, the gate 11 for limiting the X-ray radiation range is used as described above, but this conventional gate 11 has a structure with one circular opening in the center. In a state where the position is quite far from the radiation window 5, the focal position A
The X-rays generated from the focal point position B exceed the area of each focal point, creating an overlapping off-focus X-ray range, and cannot be separated into proper X-rays in each focal field. Therefore, the image quality of stereoscopic photography becomes abnormal.
Further, the seal structure inside and outside the container 2 is also complicated.

This idea was created in view of the above circumstances, and it eliminates out-of-focus X-rays and properly separates the X-rays of each focal field into left and right sides, improving image quality, as well as stereo X-rays with a unique seal structure. The purpose is to provide pipe equipment.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings. This invention is an improved X-ray radiation range limiting gate in order to eliminate the above-mentioned conventional drawbacks, and is constructed as shown in FIGS. 2a and 2b.
I will only explain the area near the gate. The same parts as in the conventional example (FIG. 1) are designated by the same reference numerals.The X-ray emission opening 7 of the container 2 is provided with an X-ray emission range limiting gate 19. In this case, conventionally the gate was attached via a seal component 8, but in this invention the gate 19 is attached inside and the seal component 20 is located outside of the gate 19. That is, the gate 19 is in direct contact with the container 2 and the lead plate 6 on the inner wall of the container.

Now, as is clear from FIG.
It is formed into a slightly conical shape in order to obtain a radiation range, and a partition portion 21 is integrally formed approximately in the center to divide the opening into left and right halves. In order to obtain an appropriate X-ray radiation range, this partition portion 21 has a trapezoidal cross section, for example, and a lower end that is connected to the X-ray tube 1.
It protrudes so as to be close to the line emission window 5. Openings 22 and 23 divided into two by this partition 21
is square as shown in FIG. 2a, but it may also be circular.

The stereo X-ray tube device of this invention has the same structure as the conventional example except for the shape of the gate 19 and the position of the seal component 20, so the same parts are given the same reference numerals and detailed explanations will be omitted. Also, in Figure 2, 2
4 is the appropriate radiation range of X-rays emitted from focal position A, 2
5 is the appropriate radiation range of X-rays emitted from focal position B, 2
6 and 27 are the out-of-focus X-ray range from focal position A, 2
8 and 29 are out-of-focus X-ray ranges from focal position B.

The stereo X-ray tube device of this invention is constructed as described above and shown in the drawings, and the X-ray radiation range limiting target 19 separates the opening into two parts and is located close to the X-ray radiation window 5 of the X-ray tube 1 . Since the partition section 21 is provided, it is possible to remove out-of-focus X-rays and appropriately separate X-rays in each focal field, thereby improving image quality.

In addition, the gate for limiting the X-ray radiation range
Since the X-ray radiation windows are arranged closer together, the X-ray fields from each X-ray focus can be separated with high precision.

Incidentally, FIG. 4 shows a modification of this invention, and the same effect as the above embodiment can be obtained. That is, in the case of FIG. 4, the partition part 21 is divided into an upper part 21a and a lower part 21.
b, and the lower part 21b is the radiation window 5 of the X-ray tube itself.
It is fixed and integrated. In this case, the gate 19 can be made very easily, and the irradiation fields from the two X-ray focal points can be accurately determined and assembled.

Further, although the partition portion 21 in the above embodiments and modified examples has a trapezoidal cross-sectional shape, the cross-sectional shape is not limited to a trapezoid, but may be a rectangular or other shape.

Furthermore, although lead has been taken as an example of the X-ray shielding material for the gate 19, it is not limited to lead as long as it can shield X-rays.

As explained above, according to this invention, a stereo X-ray tube device with great practical value can be provided.

[Brief explanation of the drawing]

Figures 1a and b are a plan view and a sectional view showing the main parts of a conventional stereo X-ray tube device, and Figures 2a and b show the main parts of a stereo X-ray tube device according to an embodiment of this invention. A plan view and a sectional view, FIG. 3 is a perspective view showing the gate used in the stereo X-ray tube device of this invention, and FIG.
The figure is a sectional view showing a modification of this invention. 1 ...X-ray tube, 2...container, 3...envelope, 4
...Anode target, 5...X-ray emission window, 6...
Lead plate, 7 ...X-ray emission port, 9...O ring, 10
... Member, 12 ... Holding plate, 19 ... X-ray radiation range limiting gate, 20 ... Seal component, 21 ...
Partition part, 24... Appropriate radiation range of X-rays emitted from focal position A, 25... Appropriate radiation range of X-rays emitted from focal position B, 26, 27... Range of out-of-focus X-rays from focal position A. , 28, 29... out-of-focus X-ray range from focal position B.

Claims (1)

[Scope of claim for utility model registration]
In a stereo X-ray tube device that accommodates an X-ray tube having a radiation emission window and a plurality of X-ray focal points spaced apart from each other by a predetermined distance, a space between the seal component and the X-ray emission window is provided from the plurality of focal positions. A stereo X-ray tube device characterized in that it has a central partition that limits the radiation range of each emitted X-ray, and is provided with an X-ray radiation range limiting gate made of an X-ray shielding material.