JPH0766080B2 - X-ray diaphragm device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an X-ray diaphragm device that is provided in an X-ray imaging apparatus or the like and that limits the range of an X-ray irradiation field.

[Technical Background of the Invention and Problems Thereof] FIG. 4 is an explanatory view of the principle of the X-ray imaging apparatus. The X-rays emitted from the X-ray tube 1 pass through the subject 2 and enter the imaging unit 3 as X-ray transmission information of the subject 2. X in the shooting unit 3
An X-ray film 4 for recording the X-ray transmission information and an X-ray shielding plate 5 for determining the X-ray exposure field are arranged, and the X-ray transmission information within the range regulated by the X-ray shielding plate 5 is The X-ray film 4 is irradiated and recorded.

Here, as the X-ray shield plate 5, the one constituted by joining the lead plate 6 and the metal substrate 7 as shown in FIG. 5 is applied. Lead plate 6 with a thickness of about 2 mm to sufficiently shield X-rays
However, the total thickness t of the X-ray shielding plate 5 is about 5 mm since the thickness of the metal substrate 7 having a predetermined rigidity of about 3 mm is added as the supporting member.

By the way, as a factor that determines the image quality of the visualized X-ray photograph based on the X-ray transmission information recorded on the X-ray film 4, the magnification of the film image can be mentioned. That is, since the focus of the X-ray tube generally has a spread of about 1 mm square, the enlargement rate becomes larger as the distance l between the subject 2 and the X-ray film 4 is shorter than the distance L between the X-ray tube 1 and the subject 2. It becomes smaller and the image quality of X-ray photographs is improved.

However, even if the distance 1 between the subject 2 and the X-ray film 4 is shortened in order to improve the image quality of the X-ray photograph, the total thickness t of the X-ray shield plate 5 is about 5 mm as described above, There is a problem that the distance 1 cannot be made sufficiently short.

Further, there is a metal substrate 7'having a slightly thin metal substrate 7'as shown in FIGS. 6 and 7 in order to reduce the weight of the metal substrate 7, and ribs 7a and folded-backs 7b are provided for improving rigidity. The total thickness t of the line shield plate itself remains unchanged, and the above problems cannot be solved.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an X-ray diaphragm apparatus that is downsized and lightweight.

[Outline of the Invention] An outline of the present invention for achieving the above object is to arrange core members on both ends of an X-ray shielding member that shields X-rays, and to arrange the X-ray shielding member and the core member on both sides of the core member. At least a pair of X-ray shielding plates formed by laminating reinforcing members having higher rigidity than that of the X-ray shielding member, and moving means for moving the pair of X-ray shielding plates in opposite directions via rope members. It is characterized by doing.

[Examples of the Invention] Hereinafter, the present invention will be specifically described with reference to Examples.

FIG. 1 is a perspective view showing an X-ray shielding plate which is an embodiment of the present invention. As shown in the figure, this X-ray shielding plate is a reinforcing member such as a fiber reinforced plastic (FR) having rigidity higher than that of the X-ray shielding member, for example, the lead plate 6, on both surfaces.
P) 8 is adhered to form a laminated structure. Both ends of this X-ray shield in the longitudinal direction (only one end is shown in the drawing)
Is a portion that is not irradiated with X-rays, and therefore does not need to be a lead material, and a lightweight material such as aluminum may be used as the core material 9.

When the X-ray shield plate is constructed in this way, a lead plate 6 with a thickness of 2 mm
FR itself contributes to the rigidity of the X-ray shield, and FR
Even if the thickness per P sheet is 0.5 mm, the same rigidity as the conventional one can be obtained. Moreover, the total thickness t'of the X-ray shielding plate is 3 (= 0.5 × 2 + 2) mm, which is about 60% of the thickness of the conventional one.

As described above, in this embodiment, the FRP 8 is adhered to both surfaces of the lead plate 6 so that the lead plate 6 itself has an X structure.
This is to contribute to the rigidity of the entire line shielding plate, and unlike the conventional case, the metal substrate 7 is bonded to only one surface of the lead plate 6, and the overall rigidity does not depend only on the metal substrate 7. Despite reducing the total thickness of the X-ray shielding plate, it is possible to exhibit the same rigidity as the conventional one. By reducing the total thickness of the X-ray shielding plate, the distance between the subject 2 and the X-ray film 4 can be made shorter than before, and as a result, an X-ray photograph with better image quality than before can be obtained in the X-ray imaging apparatus. It becomes possible to obtain.

Further, since the FRP is used, the weight of the X-ray shielding plate as a whole can be reduced, which is extremely advantageous in designing a mechanism for sliding the X-ray shielding plate.

Next, a case where the X-ray shielding plate according to the present invention is attached to the imaging unit (X-ray diaphragm device) 3 of the X-ray imaging apparatus will be described.

2 and 3 are explanatory views showing a state in which the X-ray shielding plate according to the present invention is attached to the imaging unit.

In FIG. 2, the X-ray transmitted through the subject enters from the direction of arrow Y. A wire 15 is wound between a pulley 13 axially fixed to a motor 12 and a pulley 14 attached to an imaging unit main body 3a (in which an X-ray film is stored). Two X-ray shielding plates according to the present invention are mounted as shown by 10a and 10b, each end is connected to the wire 15, and is slid in the arrow Y direction by the rotation of the motor 12. Is made like. If the motor 12 rotates clockwise, X
Since the line shields 10a and 10b are close to each other, the X-ray irradiation field becomes narrower, and conversely, when the X-ray irradiation field is rotated counterclockwise, the X-ray irradiation field becomes wider.

In order to smoothly slide the X-ray shielding plate 10a (10b), it is desirable to positively utilize the core materials 9a and 9b at both longitudinal ends of the FRP 8, as shown in FIG. That is, the end portion of the core material 9a is projectingly formed in a brim shape, and the projecting portion is loosely inserted into the long groove of the guide rail 18. Guide rail 18
Is attached to the main body of the imaging unit. Also,
The end portion of the core material 9b is bent, and the guide plate 17 is sandwiched by the rollers 16 attached to the bent surface. The guide plate 17 is attached to the main body of the imaging unit.

With this structure, the X-ray shielding plate 10a (10b) can be smoothly slid.

On the drawing, attach one end of the X-ray shield 10a (10b) to the guide rail 18
Although the other end is supported by a and the other end is supported by the guide plate 17, both ends of the X-ray shield plate 10a (10b) can be supported by the guide rails or the guide plates.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments and can be appropriately modified within the scope of the gist of the present invention.

For example, in the above embodiments, the case where FRP is used as the reinforcing member has been described, but the rigidity can be further increased by using CFRP (carbon fiber reinforced plastic).

[Effects of the Invention] As described above, according to the present invention, since a lightweight X-ray shield having a predetermined rigidity and a small total thickness is used, a rope member is used as a moving means of the X-ray shield. Since it can be used and the moving means is small and lightweight, it is possible to provide an X-ray iris device which is downsized and lightened, and a subject in an X-ray imaging apparatus equipped with this X-ray iris device. By shortening the distance between the X-ray film and the X-ray film, it is possible to obtain an X-ray photograph with excellent image quality.

[Brief description of drawings]

FIG. 1 is a perspective view showing an X-ray shielding plate according to an embodiment of the present invention, and FIGS. 2 and 3 show a state in which the X-ray shielding plate according to the present invention is attached to an imaging unit of an X-ray imaging apparatus. 4 is an explanatory view of the principle of the X-ray imaging apparatus, FIG. 5 is a perspective view showing a conventional X-ray shielding plate, and FIGS. 6 and 7 are metal substrates in the conventional X-ray shielding plate. FIG. 6 ... Lead plate (X-ray blocking member), 8 ... Fiber reinforced plastic (reinforcing member).

Claims (3)

[Claims] 1. A core member is arranged on each end of an X-ray shielding member for shielding X-rays, and reinforcing members having higher rigidity than the X-ray shielding member are provided on both sides of the X-ray shielding member and the core member. At least a pair of X-ray shielding plates formed by stacking;
An X-ray diaphragm device comprising: a moving unit that moves the pair of X-ray shielding plates in opposite directions via a rope member. 2. The X-ray diaphragm device according to claim 1, wherein the X-ray shielding member is a lead plate. 3. The X-ray diaphragm device according to claim 1 or 2, wherein the reinforcing member comprises a fiber reinforced plastic.