JPH0434810Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an X-ray detector, and particularly to the structure of an X-ray detector used in combination with an indirect X-ray imaging table.

[Prior art]

In an X-ray indirect photography device that converts an X-ray image of a subject such as a human body into visible light using a fluorescent screen and photographs the visible image on a film, an automatic exposure mechanism such as a photo timer and an X-ray detector are combined. A device is used that automatically equalizes the degree of blackening of the image transferred onto the film.

In the X-ray detector, for example, as shown in FIG. 4, a light window 6 for frontal chest photography for collecting light from a predetermined position of a fluorescent screen 8 provided on the front surface of a dark box 1 is equipped with a photoelectron intensifier. It is provided on the front surface of the doubler tube 3.

Normally, when photographing a part of a subject, for example, the front of the chest, an X-ray detector with only a light window 6 for front chest photography in a light field 11 as shown in FIG. 5 is used.

[Problem that the invention attempts to solve]

However, in recent years, opportunities for lateral chest imaging have increased, and with conventional X-ray detectors for frontal chest imaging, the light receiving area (lighting field) is too wide, as shown in Figures 5 and 6. It was unsuitable for photography.

In other words, although chest diagnosis using X-rays is increasingly performed using X-ray photographs obtained by frontal chest photography and lateral chest photography, the conventional method for frontal chest photography is When performing chest side imaging of a subject with a thin chest using only the light field, as shown in Figure 7, a primary X
Since the visible light 13 enters, there is a problem in that the automatic exposure mechanism operates prematurely, resulting in insufficient photographic density.

The present invention has been made to solve the above problems.

The purpose of the present invention is to provide a technology that allows an X-ray detector used in combination with an indirect X-ray imaging table to obtain an X-ray photograph of the appropriate density of the photographed region even if the photographed region of the subject is different. There is a particular thing.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical devices among the devices disclosed in this application is as follows.

In other words, in the present invention, in an X-ray detector used in combination with an indirect X-ray imaging table that converts X-rays into visible light and takes photographs, it is possible to Provide at least two lighting windows on the front of the case of the photomultiplier tube attached to the detector body, which allow light of a size suitable for a specific imaging area such as the side surface,
The main feature is that a photomultiplier tube is provided corresponding to the lighting window, and a switching means is provided for switching the use of a plurality of lighting windows depending on the size of the imaging site.

For example, you can put two miniature tubes in the X-ray detector case, and set the window that lets in visible light from the fluorescent screen of the indirect X-ray imaging table to the size for frontal chest imaging and lateral chest imaging. , the light is guided to the photomultiplier tube of each miniature tube, and the amount of light is detected to operate an automatic exposure control mechanism.

[Effect]

According to the above-mentioned means, a photomultiplier tube attached to the detector body is provided with a light receiving window that collects the converted visible light in a size suitable for a specific imaging region such as the front or side of the chest of the subject. By providing at least two light-emitting windows on the front of the case, providing photomultiplier tubes corresponding to the light-emitting windows, and providing a switching means for switching and using the plurality of light-emitting windows depending on the size of the imaging site, for example, By setting the lighting field for frontal chest imaging to be wide and the lighting field for lateral chest imaging to be narrow, both images will not be taken at the same time, so they can be switched and used to suit each purpose. An X-ray photograph with appropriate density can be obtained.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

In addition, in all the figures for explaining the examples,
Components having the same function are given the same reference numerals, and repeated explanations thereof will be omitted.

Figure 1 shows an X-ray detector according to an embodiment of the present invention.
FIG. 2 is a side view of FIG. 1, and FIG.
FIG. 2 is a front view of FIG. 1;

As shown in FIG.
It is attached to the top surface of the camera in a light-shielding manner. A photomultiplier tube case 5 is attached to the lower surface of the detector main body 2, and therein a first photomultiplier tube 3 and a first lighting window 6 for collecting light for frontal chest photography.
In addition, a second photomultiplier tube 4 and a second lighting window 7 are provided for lighting for chest side imaging. Further, on the front surface of the dark box 1 of the indirect imaging stand, a fluorescent plate 8 is attached in a light-shielding manner to form a visible image by receiving X-rays from an X-ray tube (not shown). A lead-containing glass 9 is provided on the rear surface of the fluorescent screen 8, and a grid 10 is provided on the front surface thereof.

Next, the operation of the X-ray detector of this embodiment will be explained.

When the subject is irradiated with X-rays from the X-ray tube, the X-rays strike the fluorescent screen 8 and a visible image is projected. A part of this visible image is illuminated, and the first photomultiplier tube 3 and the first light window 6 are selected for illumination in the case of front chest imaging, and the light field 11 thereof is widened. In addition, for lighting in the case of chest side imaging, the first photomultiplier tube 3 and the first lighting window 6 to the second
It is switched to the photomultiplier tube 4 and the second lighting window 7, and its lighting field 12 is narrowed. in this way,
Lighting for frontal chest imaging and lighting for lateral chest imaging is achieved by switching the photomultiplier tube and lighting window to set the appropriate lighting field size for the area of the subject to be imaged, and to adjust the area that protrudes from the subject. Therefore, it is possible to take X-ray photographs with appropriate density for both frontal chest photography and side chest photography.

Although the present invention has been specifically explained above based on the embodiments, it goes without saying that the present invention is not limited to the above embodiments and can be modified in various ways without departing from the gist thereof.

For example, in the embodiment described above, an example was described in which two lighting windows and two photomultiplier tubes were provided to let in a specific portion of visible light, but the number may be increased to three or more as necessary. In addition, one photomultiplier tube can be used for both purposes, and multiple lighting windows can be provided, and the optimal lighting window can be selected according to the subject, and the photomultiplier tube can be moved to the position corresponding to the selected lighting window. You can also do this.

[Effect of idea]

As explained above, according to the present invention, a light receiving window is attached to the detection main body to let in the converted visible light in a size suitable for a specific imaging area such as the front or side of the chest of the subject. At least two photomultiplier tubes are provided on the front surface of the case, the photomultiplier tubes are provided in correspondence with the lighting windows, and a switching means is provided for switching and using the plurality of lighting windows depending on the size of the imaging site. For example, if the lighting field for frontal chest imaging is wide and the lighting field for lateral chest imaging is narrow, both images will not be taken at the same time and can be used interchangeably. It is possible to obtain an X-ray photograph with an appropriate density suitable for the purpose.

[Brief explanation of the drawing]

Figure 1 shows an X-ray detector according to an embodiment of the present invention.
A partially cutaway perspective view of the state installed on the indirect radiography table, Figure 2 is a side view of Figure 1, and Figure 3 is a side view of Figure 1.
The front view and FIGS. 4 to 7 are diagrams for explaining problems with conventional X-ray detectors. In the figure, 1... Dark box of indirect imaging stand, 2... X-ray detector main body, 3... First photomultiplier tube, 4... Second photomultiplier tube.
Photomultiplier tube, 5...Photomultiplier tube case, 6...
...First lighting window, 7... Second lighting window, 8... Fluorescent screen, 9... Lead-containing glass, 10... Grid, 11
. . . Lighting field for front chest imaging, 12 . . . Lighting field for lateral chest imaging.

Claims (1)

[Scope of utility model registration request] In an X-ray detector that is used in combination with an X-ray indirect photography table that converts X-rays into visible light and takes photographs, it uses the converted visible light to capture specific areas such as the front or side of the chest of the subject. At least two lighting windows are installed on the front of the case of the photomultiplier tube attached to the detector body, and the photomultiplier tubes are installed in correspondence with the lighting windows, and multiple lighting windows are installed in front of the case of the photomultiplier tube attached to the detector body. An X-ray detector characterized in that it is provided with a switching means for switching the window according to the size of the imaging region.