JPH0475000A - X-ray scanning device - Google Patents

Abstract

PURPOSE:To shield X-ray with small and light material and enable scanning of X-ray beam in high speed and high accuracy by providing a fixed shield on the inner periphery and/or outer periphery and having a bank opening on the opposite side of inner periphery and/or outer periphery. CONSTITUTION:An annular scanner 2 which rotates around the axis on the X-ray focus of an X-ray generator 1 ad has a penetration hole 3 from the axis to the periphery direction, colimaters 5A, 5B having a center hole fixed on the inner periphery and/or outer periphery of the penetration hole 3 of the annular scanner 2, and a fixed shield 4 put on the inner periphery and/or outer periphery of the scanner 2 having an opening on the opposite part of the inner periphery and/or outer periphery of the scanner 2, are provided. Therefore, the X-ray having passed the outside of the scanner 2 is shielded with a pair of shields put at both sides at the bottom end of the scanner 2. By this, X-ray is shielded with small and light material and the X-ray can be scanned in high speed and high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an X-ray scanning device used in a non-destructive inspection device or the like.

(Prior Art) In FIG. 7 showing an example of a conventional X-ray scanning device, a cylindrical X-ray generating device 1 is connected to a drive mechanism (not shown) below the radiation opening on the bottom surface of the cylindrical X-ray generating device 1. A disc-shaped rotating disc 12 made of lead with slits 13 formed in the direction.
are placed sideways and opposite each other.

Further below this rotating disk 12, a fixed shield 14 in the shape of a rectangular plate with a slit 15 formed in the center is placed in parallel.

In the X-ray inspection apparatus configured in this way, by rotating the rotary disk 12 clockwise in the direction of arrow A in FIG. The X-ray passage port 16 shown in the figure corresponds to the rotation angle of the rotating disk 12.

As shown by arrow B in the figure, the slit 15 of the fixed shield 14
from one side to the other.

As a result, in the X-ray inspection apparatus configured as described above, the scanning speed of the X-ray beam is proportional to the outer diameter and rotational speed of the rotating disk 12, and the scanning speed of the X-ray beam passing through the X-ray passage port 16 is The cross-sectional area is determined by the widths of the slits 13 and 15.

(Problem to be Solved by the Invention) However, in the X-ray scanning device configured as described above, as shown in FIG. ,the result,
Since the shape and size of the X-ray spot irradiated onto the object (not shown) also changes, the detection ability differs depending on the irradiation location on the object.

In addition, when using spot X-rays, the efficiency of X-ray utilization decreases, so in order to obtain the amount of X-rays necessary for detection by the sensor in a short time, the amount of X-ray radiation must be increased. It won't happen.

Furthermore, if the material to be examined has a large X-ray absorption coefficient, high-energy X-rays are required.

On the other hand, since the rotating shield 12 and the fixed shield 14 must completely shield X-rays except for the slit 13.15, they must be made of a material with a high specific gravity such as lead.
The thickness must be increased.

Furthermore, in order to widen the scanning width 17, the diameter of the rotating disk 12 must be increased, so the rotating disk 12 becomes larger and its weight increases.

However, since the rotating disk 12 must be rotated at a high speed and at a constant speed, the above-mentioned large diameter, thick, and heavy rotating disk 12 conflicts with this requirement.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain an X1s inspection device that is small and lightweight, can shield X-rays, and can scan X-rays at high speed and with high precision.

[Structure of the invention]

(Means and Effects for Solving the Problems) The present invention provides an X-ray scanning device that inspects a subject by irradiating the subject with an X-ray beam, with the X-ray focal point of the X-ray generator as the axis of rotation. An annular scanner that rotates and has a through hole formed in the outer circumferential direction from the axis, a collimator that has a center hole that is inserted into the inner periphery or the outer periphery of the through hole of the annular scanner, and the inner periphery or the outer periphery of the scanner. By providing a fixed shield with an opening formed on the inner circumference or the outer circumference of the scanner, it is possible to shield X-rays with a small size and light weight, and scan the XG beam with high speed and high precision. It is an X-ray scanning device.

(Embodiment) Hereinafter, one embodiment of the X-ray scanning device of the present invention will be described with reference to the drawings. However, parts that overlap with FIGS. 7 and 8 are omitted.

FIG. 1(a) is a perspective view showing the main parts of the X-ray scanning device of the present invention, FIG. 1(b) is a cross-sectional view showing the main parts of FIG. 1(a), and FIG. FIG. 1(a) is a cross-sectional view, and FIG. 3 is a vertical cross-sectional view of FIG. 1(a).

In FIGS. 1 to 3, a scanner 2, which is approximately annular and whose cross section is roughly as shown in FIG. connected to a drive mechanism. This scanner 2 has two images, one shown in FIG.
As shown in FIG.
An annular first collimator 5A and a second annular collimator 5B are inserted and fixed at the inner and outer ends of the through hole 3, respectively.

Further, a pair of substantially gutter-shaped fixed shields 4 are provided below the X-ray generator 1 so as to sandwich the lower end of the scanner 2. They are fixed so that they overlap at a certain distance.

Now, in the X-ray scanning device configured in this way,
A part of the X-rays emitted radially from the focal point 7 of the X-ray generating bag N1 at the radiation angle α as shown in FIGS. The light enters the through hole 3 from the center hole, passes through the center hole of the second collimator 5A, and is irradiated onto a subject (not shown). And scanner 2
X-rays passing through the outside of the scanner 2 are blocked by a pair of fixed shields 4 provided on both sides of the lower end of the scanner 2.

Therefore, the width of the fixed shield 4 in the arcuate direction is 2α, which is twice the radiation angle α of the X-rays, as shown in FIG.
It is sufficient to have a width that covers an angle corresponding to β.

As a result, in the X-ray scanning device configured in this way, it is possible to form a thick X-ray shielding portion in the X-ray transmission direction in the scanner 2 surrounding the through hole 3 in the X-ray emission direction. It is possible to reduce the weight of rotating parts such as

Therefore, high-speed and constant-speed rotation becomes easy, and a highly accurate scanner becomes possible.

Also, compared to the energy change of X-rays in the axial direction of the X-ray generator shown by arrow B in Figures 1(a) and 2, the amount of energy change in X-rays in the direction of arrow B2 in Figure 3 is Therefore, the X-ray inspection apparatus has a small amount of energy change due to the scanning angle of the X-ray beam due to the rotation of the scanner 2.

Furthermore, since the thickness of each collimator 5A, 5B is thin, the center hole of each collimator SA, 5B can be easily machined into any size and shape. You can get a ray beam.

In addition, in the above embodiment, the through hole 3 of the scanner 2 is
It may be provided at only one location, or any number of locations may be provided. By providing a plurality of X-rays, a plurality of X-rays can be scanned in one rotation of the scanner 2.

On the other hand, the hole diameters of the first collimator 5A and the second collimator 5B do not necessarily have to be the same diameter, and only the hole of the first collimator 5A may have a diameter necessary to obtain a predetermined X-ray beam diameter. .

Furthermore, if the focal point 7 of the X-rays is very small, the collimator may be only the outer collimator 5A shown in FIG. 4, and if the focal point 7 of the X-rays is large as shown in FIG. It is better to provide it in two places as in the example. Further, each of the collimators 5A and 5B may be used by stacking a plurality of collimators when X-rays cannot be shielded with just one collimator.

Next, FIG. 6 is a perspective view showing another embodiment of the X-ray scanning device of the present invention.

In the figure, gutter-shaped fixed shields 8A and 8B are provided on the inner circumferential side of the scanner 2 and the outer circumferential side, respectively.
Grooves 8a and 8b are formed at the center facing the inner and outer peripheries.

In this case, the inner fixed shield 8A has a narrow width and can block X-rays in the thickness direction of the scanner 2, and since the X-ray shielding is double, the thickness of the fixed shields 8A and 8B for shielding can be reduced. It has the advantage of being thin.

In this case as well, depending on the size of the X-ray focal point, the fixed shield 8A may be omitted and the thickness of the fixed shield 8B may be increased.

Further, the fixed shield may be a flat plate, as shown by the dashed line in the figure.

[Effects of the Invention] As described above, according to the present invention, in an X-ray scanning device that inspects a subject by irradiating the subject with an xm beam, the X-ray focal point of the An annular scanner with a through hole formed in the outer circumferential direction, a collimator with a center hole inserted on the inner circumference or outer circumference of the through hole of this scanner, and a scanner provided on the inner circumference or outer circumference of the scanner. A fixed shield with a band-shaped opening formed on the inner periphery or opposite the outer periphery is provided, so it is small and lightweight, can shield X-rays, and can scan the X-ray beam at high speed and with high precision. An X-ray scanning device can be obtained.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view of the main parts of an embodiment of the X-ray scanning device of the present invention, FIG. 1(b) is a cross-sectional view showing the main parts of FIG. 1(a), and FIG. 1(a) is a cross-sectional view, FIG. 3 is a vertical sectional view of FIG. 1(a), FIGS. 4 and 5 are diagrams showing the operation of the X-ray scanning device of the present invention, and FIG. 6 is a cross-sectional view of FIG. 1(a). FIG. 7 is a perspective view of the main part showing another embodiment of the X-ray scanning device of the present invention.
FIG. 8 is a perspective view of the main parts of an example of a ray scanning device, and is a diagram illustrating the operation of a conventional X-ray scanning device. 1...X-ray generator 2...Scanner 3...
Through hole 4...Fixed shield 5A...First collimator 5B...Second collimator (8733
) Agent Patent Attorney Yoshiaki Inomata (and other names) (b) Figure Figure Figure Figure Figure Figure Figure

Claims (1)

[Claims] In an X-ray scanning device that inspects a subject by irradiating the subject with X-rays emitted from an X-ray generator, the X-ray focal point of the X-ray generator is used as an axis of rotation. an annular scanner that rotates and has a through hole formed on the outer periphery from the axial direction; a collimator that has a center hole that is inserted into the outer periphery or the inner periphery of the through hole of the scanner; An X-ray scanning device characterized in that a fixed shield is provided around the scanner and has a band-shaped opening formed at a portion facing the outer circumference or the inner circumference of the scanner.