JPS646814Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an undertube type X-ray fluoroscopic imaging table, and more specifically, an undertube type X-ray fluoroscopic imaging table having an improved grid device for removing scattered radiation. It's about the stand.

[Conventional technology]

1 and 2 show a conventional undertube type fluoroscopic imaging table. This fluoroscopic imaging table consists of a table 1 on which a subject is placed, an X-ray tube device 2 placed on the bottom of the table, an X-ray flux aperture device 3 attached to the X-ray tube device, and an image-input device placed on the top of the table. a support member 5 incorporating video devices such as a tensifier 6, a television camera 7, and a film changer (not shown);
It is equipped with a grid 8 for removing scattered radiation and a guide rail 9 for the grid. The grid 8 is
As clearly shown in FIG. 2, it is fitted into a guide groove 9' formed in the guide rail 9. In addition,
The film 10 is set at the center position A of the X-ray irradiation field within the support member 5 via a film exchanger.

In the above-mentioned X-ray fluoroscopic imaging table, in normal direct imaging, it is necessary to bring the film 10 as close as possible to the subject 4 and perform imaging at a low magnification. At that time, in order to remove scattered radiation, it is normal to place a grid 8 at the center position A of the X-ray irradiation field and take the image.
In enlarged photography, since the subject 4 and the film 10 are photographed apart from each other, the grid 8 becomes unnecessary due to the Gredel effect. Therefore, the grid 8 is moved along the guide rail 9 from the position shown by the solid line in FIG. 1 to the retracted position B shown by the chain line by a moving means (not shown).

[The problem that the idea aims to solve]

Such an X-ray fluoroscopic imaging table has a guide rail 9
Fit the grid 8 into the guide groove 9' formed in the
Since the grid 8 is movably supported, a gap g is required between the bottom surface 5' of the supporting member 5 on the film side and the grid 8. Therefore, when performing low magnification imaging in which the grid 8 is placed at the center position A of the X-ray irradiation field, the gap g
However, the film 10 cannot be brought close to the subject.

SUMMARY OF THE INVENTION An object of the present invention is to provide an undertube type X-ray fluoroscopic imaging table that can further reduce the distance between the subject and the film.

[Means to solve the problem]

In the undertube type X-ray fluoroscopic imaging table of the present invention, the guide member that guides the grid is rotatably attached to the support member around one end, and the other end is connected to the support member by a spring. When a cam plate is attached to the support member in which the device is incorporated, and the holding frame of the grid has a cam follower that contacts the cam surface of the cam plate, and the cam plate moves the holding frame to the center position of the X-ray irradiation field. The holding frame is characterized in that it is provided with a cam profile that substantially eliminates the clearance between the support member and the grid and creates a clearance between the support member and the grid when the holding frame is moved. .

[Effect]

When the grid is in the center position of the X-ray field, the guide member and the spring bring the grid into close contact with the support member, and when the holding frame is moved over the guide member,
The cam plate rotates the guide member against the spring,
The gap necessary for movement is created between the grid and the support member, and the grid can be moved smoothly, so when the grid is at the center of the X-ray irradiation field, there is no gap between the support member and the grid. The object can be brought closer to the imaging device without requiring a gap for moving the object.

〔Example〕

3 and 4 show the front end of the imaging device in an embodiment of the X-ray fluoroscopic imaging device of the present invention, and show guide shafts 11 and 12, which are guide members of the holding frame, and guide shafts 11 and 12 for removing scattered radiation. It is provided with a holding frame 17 for the grid 16, a means for moving the holding frame 17, and a means for operating the holding frame 17.

The guide shafts 11 and 12 are provided on both sides of a support member 5 incorporating an imaging device such as an image intensifier or a film changer.
Each guide shaft 11, 12 has an end supported by a pin 13 on the side of the center position C of the X-ray irradiation field, and an end on the side of the retracted position D with a vertically long guide groove 14'.
A tension spring 15 is provided at the end on the side of the retracted position D to pull the end toward the upward direction. Therefore, each of the guide shafts 11 and 12 is rotated about the pin 13, and is biased by the tension spring 15 to rotate in a direction in which the end side on the retracted position D side rises in the vertical plane.

The holding frame 17 supports the guide shafts 11 and 12.
When viewed from the axial direction of the support member 5, the width of the grids 16 are arranged on the bottom surface 5' side of the support member 5, and are formed in a shape that extends from the bottom surface 5' on the film 10 side of the support member 5 to both sides and fit on the outside thereof. It supports both ends of the direction. Further, the holding frame 17 is supported by the guide shafts 11, 12 via a set of bearings 18, 18 and a set of bearings 19, 19 provided on both sides, and is supported by the guide shafts 11, 12 along the guide shafts 11, 12 as shown in FIG. It is attached so that it can move back and forth between the center position C of the X-ray irradiation field and the retreat position D shown in FIG. Further, at the upper end of the holding frame 17, a connecting member 25 having a vertically long elongated hole 26 and a cam follower 2 are provided.
9 and 30 are provided.

The means for moving the holding frame 17 is installed above the guide shaft 11 provided on one side of the support member 5. The moving means includes a reversible rotary motor 20 attached to one end of the guide shaft 11 on the side of the support member 5;
A driving wheel 21 attached to the rotating shaft, a driven wheel 22 attached to the other end side of the guide shaft 11 on the side of the support member 5, and the driving wheel 21
A winding transmission member 23 is stretched between the driven wheel 22 and a pusher 24 connected to the side facing the guide shaft 11, and the pusher 24 is received in the elongated hole 26 and attached to the upper end of the holding frame 17. A connecting member 25 is provided. By rotating the motor 20 in the forward direction, this moving means moves the holding frame 17 from the center position C of the X-ray irradiation field through the driving wheel 21, the driven wheel 22, the winding transmission member 23, the pusher 24, and the connecting member 25. The holding frame 17 is configured to be moved from the retracted position D to the X-ray irradiation field center position C by moving it to the retracted position D and rotating the motor 20 in the opposite direction.

The operating means for the holding frame 17 is composed of cam plates 27, 28 fixed above the guide shafts 11, 12 on both sides of the support member 5, cam followers 29, 30 provided at the upper ends of both sides of the holding frame 17 and abutting against the cam surfaces of the cam plates 27, 28, and the tension spring 15 which urges the holding frame 17 upward via the guide shafts 11, 12. When the holding frame 17 is moved from the X-ray radiation field center position C to the retracted position D by the moving means, the cam followers 29, 30 are pushed down by the cam plates 27, 28 against the spring force of the tension spring 15, thereby lowering the holding frame 17, and when the holding frame 17 is moved from the retracted position D to the X-ray radiation field center position C, the cam plates 27, 28 push down the cam followers 29, 30 against the spring force of the tension spring 15, thereby lowering the holding frame 17, and when the holding frame 17 is moved from the retracted position D to the X-ray radiation field center position C, the cam plates 27,
By cooperation of the tension spring 15, the cam followers 29 and 30 and the tension spring 15, the holding frame 17 can be raised to a position where the gap between the bottom surface 5' of the support member 5 on the film 10 side and the grid 16 can be made substantially zero.

The X-ray fluoroscopy table of the above embodiment is operated and functions as follows.

That is, the holding frame 17 of the grid 16 is positioned at the center position C of the X-ray irradiation field as shown by the solid line in FIG.
When the holding frame 17 is placed in the position shown in FIG. The holding frame 17 is lifted, and the grid 16 supported by the holding frame 17 is brought into close contact with the bottom surface 5' of the supporting member 5 on the film 10 side. Therefore, grid 16
During low-magnification imaging using the X-ray camera, the film 10 set in the support member 5 can be brought as close as possible to the subject 4 via the film exchanger, so a good X-ray photograph can be taken.

Next, since the grid 16 is not required during enlarged photography, the motor 20 of the moving means of the holding frame 17 is rotated, and the driving wheel 21, the driven wheel 22, the winding transmission member 23, and the pusher 2 attached thereto are rotated.
4. Through the connecting member 25 provided on the holding frame 17, move the holding frame 17 of the grid 16 along the guide shafts 11 and 12 from the X-ray irradiation field center position C to the retracted position as shown by the imaginary line in FIG. Move to D. During this movement, the holding frame 17 is pushed down against the spring force of the tension spring 15 due to the action of the cam plates 27, 28 and cam followers 29, 30 of the operating means of the holding frame 17, and the center position of the X-ray irradiation field C As the film 1 of the supporting member 5 moves toward the retracted position D, the gap gradually increases.
Interference between the bottom surface 5' on the zero side and the grid 16 can be avoided. Note that the gap is indicated by the reference numeral 31 in FIG.

When performing low-magnification imaging again, the holding frame 17 can be moved to the X-ray irradiation field center position C by rotating the motor 20 of the main moving stage of the holding frame 17 in the opposite direction. Moreover, the bottom surface 5' of the support member 5 on the film 10 side is
By bringing the grid 16 into close contact with the subject 4, the film 10 can be brought as close as possible to the subject 4. In the above-described low magnification imaging, the grid 16 remains fixed at the center position C of the X-ray irradiation field until the imaging is completed, so the foil of the grid 16 is photographed together with the image of the subject 4. In order to blur this foil image, in the present invention, the motor 20 is rotated from immediately before to immediately after the photographing to move the grid 16 and erase the foil image. This movement is perpendicular to the direction of the foil, and can be easily performed since it is only necessary to move several foils within the photographing time.

In this embodiment, the holding frame 17 and its moving means are connected through the engagement of the elongated hole 26 formed in the connecting member 25 and the pusher 24.
The guide shafts 11 and 12 supporting the frame are attached so that they can rotate in a vertical plane with one end as the rotation center, so when the holding frame 17 is raised and lowered, trouble between the holding frame 17 and its moving means can be avoided. , and no trouble occurs between the holding frame 17 and the guide shafts 11 and 12.

In the present invention, the shape of the holding frame 17 is not limited to that of the illustrated embodiment, but may be any shape that can support both ends of the grid 16 in the width direction and align with other members.

Furthermore, the means for moving the holding frame 17 is not limited to the structure shown in the drawings.
12 along X-ray irradiation field center position C and retreat position D
Any device that allows for reciprocal movement between the two locations is sufficient. moreover,
The operating means of the holding frame 17 is not limited to the plate cam, but also the X
A cam that makes the gap between the bottom surface 5' of the support member 5 on the film side and the grid 16 substantially zero at the radiation field center position C, and forms a gap when moving from this position to the retracted position D. A grooved cam with a contour or the like can be used.

[Effect of idea]

As explained above, the undertube type X-ray fluoroscopic imaging table of the present invention reduces the gap between the support member and the grid to substantially zero when the grid is moved to the center position of the X-ray irradiation field, Moreover, when moving the holding frame between the center position of the X-ray irradiation field and the retracted position, a gap is formed between the support member and the grid, so that the grid can be moved smoothly. Therefore, compared to conventional fluoroscopic imaging devices, the distance between the subject and the film can be reduced, and clearer images can be obtained.

[Brief explanation of drawings]

Figure 1 shows an X with conventional grid support means.
2 is a left side view of FIG. 1, FIG. 3 is an enlarged side view of main parts showing an embodiment of the present invention, and FIG. 4 is a view of ()-- of FIG. 3. ( ) is a line cross-sectional view. 4...Subject, 5...Supporting member such as photomultiplier tube and film exchanger, 5'...Bottom surface of support member on film side, 10...Film, 11, 12...
Guide shaft as guide member of holding frame, 1
3...Pin that is the center of rotation of the guide shaft, 1
5... Tension spring biasing the holding frame upward via the guide shaft, 16... Grid, 17...
Grid holding frame, 20... motor constituting a means for moving the holding frame, 21... driving wheel, 22... driven wheel, 23... wrapping transmission member, 24...
Same pusher, 25... Connection member between the holding frame and moving means, 27, 28... Cam plate constituting the operating means of the holding frame, 29, 30... Same cam follower, C...
... X-ray irradiation field center position, D... Grid retreat position.

Claims (1)

[Scope of utility model registration request] A support member incorporating an X-ray tube device, an imaging device such as an image intensifier or a film exchanger, a grid for removing scattered radiation disposed between the X-ray tube device and the imaging device, and a center of the X-ray irradiation field. An undertube comprising: a guide member disposed on the support member between the position and the retracted position; and a holding frame that holds the grid and causes the grid to reciprocate along the guide member. Shape X
In a fluoroscopic imaging table, one end of the guide member is rotatably attached to the support member, the other end is connected to the support member by a spring, the support member is attached with a cam plate, and the holding frame is attached to the cam plate. The cam plate has a cam follower that contacts the cam surface of the grid, and when the cam plate moves the holding frame to the center position of the X-ray irradiation field, the gap between the support member and the grid becomes substantially zero, and the holding frame An X-ray fluoroscopic imaging table characterized in that it is provided with a cam contour that forms a gap with a support member when the table is moved.