JPS6327677B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an aperture device for use with a plurality of radiation sources located in a plane, each radiation beam substantially covering a single area of an object, comprising: transversely movable and comprising an aperture for each of the radiation sources for focusing the radiation beam, the distribution of the apertures being adapted to the distribution of the radiation sources for optimum image transmission; The present invention relates to an aperture device for use with multiple radiation sources.

The aperture device includes a flat plate placed between the radiation source and the object. The plate includes several groups of fixed apertures, each radiation beam from a different radiation source covering at least approximately the same area of an object transmitted through the group of apertures. In this case, the size of the apertures in a group depends on the distance between the corresponding radiation source and the aforementioned plate. By laterally moving and shifting the plate, different groups of apertures can be selected to apply the radiation beam to object areas of different sizes in stages. However, since there is a limit to the number of groups of apertures provided in this plate, the radiation beam can only be applied to a limited number of groups of object areas.

For this reason, aperture devices with fixed apertures may vary substantially in the dimensions of the object area.
It can be used only within a certain limited range for medical X-ray diagnostic equipment. Furthermore, in order to reduce the radiation load on the object and the scattered radiation, it is necessary to constrict the individual radiation beams to some extent so that they can illuminate only the area of the object that is to be examined.

SUMMARY OF THE INVENTION The object of the invention is to provide an aperture device which is constructed so that radiation beams from different radiation sources located in a plane can be successively focused in a simple manner.

According to the present invention, in the aperture device mentioned at the beginning, the aperture device is composed of at least two aperture plates, these aperture plates are positioned parallel to the plane in which the radiation source is positioned, and the aperture device It is characterized in that the plates are provided with passages that define openings by relative lateral movement of the aperture plates.

If the radiation source is located in only one plane (the plane of the radiation source), the aperture device can be constructed with a group of two aperture plates, for example;
The aperture plates can be arranged to be mutually movable parallel to the plane of the radiation source.

Based on the use of such aperture plates that can be moved parallel to each other, the size of the aperture can be adjusted continuously, so that the radiation beam from the radiation source is completely adapted to the dimensions of the object area to be examined. It can be adapted to For this purpose, the aperture plate is provided with so-called channels distributed in the aperture plate in correspondence with the distribution of the radiation source located in the aforementioned plane. This allows the passages to be moved relative to each other by moving the aperture plates in parallel, so that these passages can each be partially blocked by the other aperture plate. As a result, the opening can be formed and maintained.

These aperture plates can be arranged so that one aperture plate directly overlaps the other aperture plate, or they can be arranged in parallel with each other at a certain distance. In this case, it is also possible to move the aperture plates continuously or simultaneously. Such movement can also be accomplished using mechanical or electromechanical devices.

A group of aperture plates may be composed of two or more aperture plates. In this case, these aperture plates can be arranged and moved as described above.

As a result of focusing the radiation beam onto the object area, irradiation of areas that are not to be inspected can be avoided. Therefore, the radiation load on the object can be reduced. Furthermore, the scattered radiation generated during illumination of the object may be reduced, thereby increasing the resolution and contrast of the image of the object area.

In a preferred embodiment of the invention, additional groups of aperture plates are provided for focusing the radiation beams from a plurality of radiation sources, each located in relatively parallel planes, each group of aperture plates Associated with each plane in which the source is located, each aperture plate of the respective group provides a separate path S1, for the radiation beam originating from the radiation source in a plane not associated with this group.
S2, the latter radiation beam comprising:
This radiation beam is passed completely through a path at some location in the aperture plate associated with it.

If the radiation sources are located in several parallel planes, it is necessary to assign a group of aperture plates to each plate in order to successively focus the radiation beam by means of the aperture plates. The separate groups of aperture plates, which may be located different distances from each other and the associated plate, have apertures that are equal in size but may have different dimensions for different groups of aperture plates. The aperture plate is positioned in the beam path so that the passing radiation beam completely covers the same area of the object to be inspected. The aperture plate provides an additional passage for radiation beams originating from surfaces not associated therewith. However, these radiation beams
These radiation beams are not additionally constricted, since the translation allows them to completely pass through their passages in any position of the aperture plate.

If the object area to be examined is increased or decreased, the aperture is opened or closed depending on the distance between the group and the plate associated therewith. Therefore, it is necessary to move the aperture plate in parallel accordingly. This translation can be achieved simultaneously for all aperture plates manually or using mechanical or electromechanical devices.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a plane (hereinafter referred to simply as "plane") as multiple radiation sources in a common tank (not shown).
FIG. 3 schematically shows three X-ray sources placed together in a device (referred to as . . . ). Each of these three X-ray sources 1, 2 and 3 has a main radiation beam 4, 5, respectively.
and radiates 6. These beams reach an aperture device B consisting of two aperture plates B1 and B2 arranged one above the other. This aperture device B comprises apertures 7, 8 and 9 for focusing the main radiation beams 4, 5 and 6. The radiation beams 10, 11 and 12 constricted by these apertures coincide perfectly in a superposition plane 13 extending parallel to the plane E and cover the same object area 15 located inside the object 14. substantially irradiate. This object 14
can be, for example, a human body. These radiation beams 10, 11 and 12 completely cover only the object area 15 to be inspected, so that the object 1
The amount of scattered radiation generating portion 16 (the shaded portion) formed within 4 is also minimized. These radiation beams 10, 11 and 12 may be incident, for example, on an entrance screen of an X-ray image intensifier or on a radiation-sensitive layer, such as a film 17, for forming a superimposed image.

These two aperture plates B1 and B2 can be arranged, for example, by placing one aperture plate above the other aperture plate, or by placing them in parallel with each other with a very small distance between them. These aperture plates form passages 7a, 8a and 9a and 7a to form apertures 7, 8, 9.
b, 8b and 9b, respectively. The distribution of these channels on the aperture plates B1 and B2 corresponds to the distribution of the X-ray sources 1, 2 and 3 in the plane E. These aperture plates B1 and B2 can be made of lead, for example, and by translating these aperture plates B1 and B2, the passages 7a, 7b, .about.9a, 9b are shifted relative to each other,
These channels are then each partially covered by the other plate. Therefore, the radiation beams 10, 11 and 1
2 can be formed and maintained as an opening.

These aperture plates B1 and B2 can be moved relative to each other simultaneously manually or using an electromechanical device V.
Preferably, this aperture device B is mounted together with a displacement device V on the tank of the multiple radiation source, so that during the irradiation of the object area 15 this aperture device can be moved together with the multiple radiation source from different directions.

FIG. 2 is a plan view showing the aperture device B shown in FIG. 1, which is composed of two aperture plates B1 and B2. Both of these aperture plates B1 and B2 may be, for example, rectangular, and may be of equal size, for example.
These aperture plates each have three passages 7a, 8a, 9a and 7b, 8b, 9b, each of which has a rectangular shape, has the same dimensions, and whose long sides extend parallel to each other. I am keeping it there. These passages are connected to these two aperture plates B
1 and B2 are located on these aperture plates in such a way that they exactly match each other when they are not located out of alignment. In such a state, the opening device B
The object area 15 illuminated by the radiation beams 10, 11 and 12 passing through is at a maximum. By moving these aperture plates B1 and B2 in parallel in the directions indicated by arrows a, b, and c, or in an intermediate direction, the passage of one aperture plate can be changed by the other aperture plate. Each can be covered. Openings 7, 8 and 9 can thus be formed which are each bounded by the edges of the two passages 7a and 7b to 9a and 9b, respectively. These apertures 7, 8 and 9 are therefore always located in the center of the main radiation beams 4, 5 and 6. In this way, by shifting the aperture plates B1 and B2, object areas 15 of different sizes and shapes can be irradiated. Furthermore, the aperture plates B1 and B2 can also be rotated relative to each other about an axis extending perpendicular to the plane of the plates in order to form the apertures separately.

FIG. 3 shows an aperture arrangement B' for radiation sources arranged in two parallel planes. X-ray source 1
9 and 20 located on a first surface E1 and associated with the multiple radiation source 18, while a second surface E2 located below and parallel to this first surface includes:
Another X-ray source 21 and a radiation source 41 that emits visible light
and place it.

One aperture plate is placed over the other aperture plate and one aperture plate is placed over the other aperture plate as well as a first pair of aperture plates B3 and B4 associated with radiation sources 19 and 20 located in plane E1. and face E
a second pair of aperture plates B5 and B6 associated with radiation sources 21 and 41 located at 2;
Both pairs of aperture plates are placed below the radiation sources 19, 20 and 21, 41. In this case, these pairs are arranged parallel to each other and parallel to planes E1 and E2. In this case, the second pair is positioned below the first pair. It is clear that these pairs and surfaces can also be arranged in any different order.

The main radiation beams 19a and 20a emitted from the X-ray sources 19 and 20 pass through the first pair of aperture plates B3.
and corresponding openings 36 and 37 formed by passages located in B4 and offset with respect to each other as shown in FIG. Both the apertures 36 and 37 have the same shape and dimensions, and since they are located in the aperture plate, the radiation beams 33 and 34 that are focused by and pass through the apertures to be inspected are Object 2
8 same object area 27 and object area 2
They completely match in the overlapping surface 23 on the inside of 7. The radiation beams 33 and 34 are then incident on a radiation sensitive layer 30, for example an X-ray film, to form a superimposed image.

The radiation beams 33 and 34 are connected to the second pair of aperture plates B.
5 and B6, in this second pair of aperture plates B5 and B6,
In each position of these parallel movable aperture plates, another passage S2 is provided through which the radiation beams 33 and 34 pass completely.
Further, the first pair of aperture plates B3 and B4 have a surface E.
The corresponding paths S for the main radiation beams 21a and 41a of the radiation sources 21 and 41 located in the
1 will be provided. Main radiation beams 21a and 41a
After passing through this passage S1, the associated opening 3
5 and 42. These apertures are also identical in shape and size and are defined by corresponding passages that are movable in parallel as shown in FIG. The aperture 35 is located in the aperture plates B5 and B6 so that the focused beam 22 is in the same object area 27 as the radiation beams 33, 34.
Alternatively, the same overlapping surface 23 can be completely irradiated. This radiation beam 22 or radiation source 21 serves to depth and adjust the desired object area 27.

The light beam 44 is focused by the aperture 42 to the object 2.
8, a light spot 45 is formed on it. This light spot corresponds to the dimensions of the object area 27. By means of this light spot, an object 28 located on the platform 29 can be positioned when it is moved relative to the radiation beams 22, 33, 34 in different directions XZY.

apertures 36, 37 and 35, 42 by translating and offsetting the aperture plates during squeezing the object area 27, depending on the distance between each pair of aperture plates and the planes E1 and E2 associated with these pairs; It is necessary to adjust the size of to different sizes. In this case, the amount of movement of the aperture plates forming these pairs is also determined depending on this distance. The distance between the first pair of aperture plates B3 and B4 and the surface E1 is d1, the distance between the overlapping surface 23 and the surface E1 is d2,
Further, the distance between the second pair of aperture plates B5 and B6 and the surface E2 is set as d3, and the overlapping surface 23 and the surface E
When the distance between 2 and 2 is d4, these distances d
The relationship d1/d2=d3/d4 can be applied between 1 and d4. Therefore, when the sizes of the openings in both pairs of aperture plates are equal, the aperture plates B3, B5 and B4, B6 located on one side are mechanically interlocked so that they can move uniformly. Can be configured.

It is clear that the invention is not limited only to the embodiments described above, but can be subjected to many modifications and variations.

[Brief explanation of the drawing]

Fig. 1 is a line diagram showing an example of a shedding device provided with a pair of aperture plates, Fig. 2 is a plan view showing the shedding device shown in Fig. 1, and Fig. 3 is a shedding device provided with two pairs of aperture plates. It is a line diagram showing an example. B, B'...Aperture device, B1 to B6...Aperture plate,
1, 2, 3, 19, 20, 21, 41...Radiation source, 4, 5, 6, 19a, 20a, 21a, 41
a... Main radiation beam, 7-9, 35-42... Aperture, 7a-9a, 7b-9b, S1, S2... Passage, 10-12, 22, 33, 34, 44... Radiation beam, 13 , 23... Overlapping surface, 14,
28...Object, 15, 27...Object area, 16...
...scattered radiation generating portion, 17,30...radiation sensing layer, 18...multiple radiation source.

Claims (1)

Claims: 1. An aperture device for use with multiple radiation sources located in a plane, each radiation beam substantially covering a single area of an object, the device comprising: a plurality of radial rays, each comprising an aperture for each of the radiation sources to focus the radiation beam, the distribution of the apertures being adapted to the distribution of the radiation sources for optimum image transmission; In the aperture device used for the source, the aperture device B is connected to at least two aperture plates B1 and B2.
, these aperture plates are positioned parallel to the plane E in which the radiation source is positioned, and
A plurality of radiation sources characterized in that the aperture plates B1 and B2 are provided with passages 7a, 7b to 9a, 9b that define apertures 7, 8, 9 by relative lateral movement of these aperture plates. opening device used for 2. Providing additional groups of aperture plates to focus the radiation beams from the plurality of radiation sources respectively positioned in relatively parallel planes E1 and E2, each group of aperture plates positioning said radiation sources; Associated with each plane, each aperture plate of the respective group comprises a further group of paths S1, S2 for the radiation beam originating from the radiation source in the plane not associated with this group, the radiation beam of the latter being 2. Aperture device for use with a plurality of radiation sources as claimed in claim 1, characterized in that the radiation beam is completely passed through a passage in any position of the aperture plate associated with the radiation beam. 3. The aperture device for use with a plurality of radiation sources according to claim 2, wherein the aperture plates forming the group are comprised of a plurality of pairs of aperture plates. 4 Each pair of aperture plates B1 and B2
A plurality of radiation sources according to any one of claims 1 to 3, characterized in that the radiation sources are mechanically connected via a moving device V so as to be able to interlock. opening device used for 5. Use in a plurality of radiation sources according to claim 2 or 3, characterized in that each pair of aperture plates located on the same side are mechanically connected to move simultaneously. Opening device. 6. The aperture device for use with a plurality of radiation sources according to claim 3, wherein the aperture plates are arranged in pairs in direct contact with each other. 7. The aperture device for use with a plurality of radiation sources according to claim 1, wherein the passage has a rectangular shape.