JPS6136992Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to improvement of an X-ray imaging device.

A conventionally used X-ray imaging device is constructed as shown in Fig. 1, and includes an X-ray tube 1, a top plate 2, an X-ray fluorescence multiplier tube 3, an X-ray fluorescence multiplier lens 4, and a camera. It consists of a camera lens 5 and a camera 6. When in use, a subject 7, a patient, is placed between the X-ray tube 1 and the top plate 2.

However, since the input surface 8 of the X-ray fluorescence multiplier tube 3 is constituted by a spherical surface with a radius R, the square pattern of the imaging region 9 causes pincushion distortion on the output surface 10 of the X-ray fluorescence multiplier tube 3. I'm getting used to it. Therefore, as a means of correcting this distortion, attempts have been made to provide the lens 4 for the X-ray fluorophore tube with barrel distortion to obtain a final film image 11 free of distortion. but,
Even this method cannot be applied to a field-switchable X-ray fluorescence multiplier tube. As shown in Figure 1,
The positional relationship between the ray tube 1, the object 7, and the X-ray fluorescence multiplier tube 3 is fixed, and by changing the electrode voltage of the X-ray fluorescence multiplier tube 3, the input surface size reflected on a predetermined output surface can be changed. , the degree of pink tension distortion at the output surface 10 differs between the 9″ mode and the 6″ mode. That is, as shown in FIG. 2, a is the case where the lens 4 for the X-ray fluorescence multiplier tube is a normal lens;
b is the 9'' mode and c is the 6'' mode, both of which are cases in which the X-ray fluorescence multiplier tube lens 4 is a distortion correction lens.
In each figure, from left to right, the pattern of the imaging site 9, the output image of the X-ray fluorescence multiplier tube, and the film image are shown in order. As is clear from Fig. 2 b and c, if the distortion correction of the lens 4 for the X-ray fluorescence multiplier tube is adjusted to the 9'' mode, the correction will be excessive in the 6'' mode, and the film image will suffer from barrel distortion. I get used to it.

This idea eliminates the above-mentioned drawbacks of the conventional method.
An object of the present invention is to provide an X-ray imaging apparatus that can accurately correct distortion in any enlargement mode.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings. According to the creator's experiments, 9″,
In a 12" class X-ray fluorophore multiplier tube, if the focal size of the X-ray tube is reduced to 0.3 mm or less, the resolution will improve due to X-ray magnification, and of course the effective field of view will become smaller and the image will be magnified. Therefore, the X-ray imaging apparatus of this invention is constructed as shown in FIG.
2. A top plate 13, an X-ray fluorescence multiplier tube 14, an X-ray fluorescence multiplier tube lens 15, a camera lens 16, and a camera 17 are sequentially arranged on the same straight line, and the X-ray tube 1
A subject 18, which is a patient, is placed between the top plate 13 and the top plate 13. In this case, the X-ray tube 12 used has a focus of 0.3 mm or less. or,
The X-ray fluorescence multiplier 14 is of a so-called single field type, and the distance L between the X-ray tube 12 and the X-ray fluorescence multiplier 14 is fixed constant. Further, the X-ray fluorescence multiplier tube lens 15 and the camera lens 1
At least one of the X-ray fluorescence multiplier tubes 14
Distortion correction for pink tension distortion has been applied. Further, either the subject 18 or the top plate 13 is movable. That is, if the subject 18 and the top plate 13 are placed at point A and photographed, the image size will be the same as in the conventional 9'' mode, and the X-ray fluorescence multiplier tube lens will be adjusted to minimize distortion. 15 or camera lens 16 or both lenses 1
5 and 16 correct distortion. Next, if the subject 18 and the top plate 13 are moved to point B, the X-ray magnification becomes L/l ₁ '(>L/l ₁ ≒ 1), and the field of view of the image incident on the X-ray fluorescence multiplier 14 becomes is smaller, but the X-ray fluorescence multiplier tube 14
There is no change in the fact that the X-ray rays are reflected on the entire input surface 19 of the screen. Therefore, distortion can be accurately corrected in this case as well. In addition, a in Fig. 4 is 9″ mode,
b shows the case of 6'' mode, which shows, from left to right, the pattern of the imaged region 20, the output image of the X-ray fluorescence intensifier tube, and the film image.

Since the X-ray imaging apparatus of this invention is constructed as described above and illustrated, distortion can be accurately corrected in any enlargement mode.

As explained above, according to this invention, an X-ray imaging apparatus with great practical value can be provided.

[Brief description of the drawings]

Figure 1 is a configuration diagram showing a conventional X-ray imaging device, and Figures 2 a to c are relationships between lens correction, imaging site pattern, X-ray fluorescence multiplier tube output image, and film image in the equipment shown in Figure 1. FIG. 3 is a configuration diagram showing an X-ray imaging apparatus according to an embodiment of the invention, and FIGS. FIG. 2 is an explanatory diagram showing the relationship between a photomultiplier tube output image and a film image. 12...X-ray tube, 13...Top plate, 14...X-ray fluorescence multiplier tube, 15...X-ray fluorescence multiplier tube lens,
16...Camera lens, 17...Camera, 18
...Subject, 19...Input surface, 20...Photography part.

Claims (1)

[Scope of utility model registration request] An X-ray tube, a top plate, an X-ray fluorophore tube, a lens for the X-ray fluorophore tube, a camera lens, and a camera are arranged in sequence on the same straight line, and a subject is placed between the X-ray tube and the top plate. In an X-ray imaging device in which
The X-ray tube has a focal point of 0.3 mm or less, the X-ray fluorescence multiplier is of a single field type, and at least one of the X-ray fluorescence multiplier tube lens or the camera lens has a focal length of 0.3 mm or less. The X-ray fluorescence multiplier tube is corrected for pink tension distortion, and the distance between the X-ray tube and the X-ray fluorescence multiplier tube is kept constant, and the top plate is movable. An X-ray imaging apparatus characterized in that enlarged imaging is possible by fixing the subject or by fixing the top plate and making the subject movable.