JPH0726845U - X-ray diaphragm device - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain an accurate irradiation field shape with minimal overlap of leaves. A base plate, a plurality of first leaves rotatably arranged via a first fulcrum pin, a plurality of second leaves rotatably arranged via a second fulcrum pin, and It includes first and second guide pins protruding from the first leaf and the second leaf, and an operation ring having a groove or hole that engages with the first and second guide pins.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an X-ray diaphragm device that narrows down an X-ray irradiation field.

[0002]

[Prior art]

In an example of a conventional device of this type, as shown in FIG. 1, two first leaves P ₁ and second leaves P ₂ are stacked in a grid pattern and squeezed into a quadrangle, on which four third leaves P ₁ are arranged. ₃ was rotatably installed to obtain an octagonal irradiation field as a whole.

[0003]

[Problems to be solved by the device]

 However, there are the following problems. That is, since the distances between the first to third leaves and the X-ray focal point are different, the magnification of each leaf on the X-ray incident surface of the image receiving device is different, and the blurring of the leaf edge (vibration of the irradiation field) varies. . The positional relationship of each leaf is hard to come out, and the octagon is prone to distort. The height of the collimator itself becomes high.

An object of the present invention is to solve the above-mentioned problems and to provide an X-ray diaphragm apparatus which can minimize the overlap of leaves and can obtain an accurate irradiation field shape.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned subject, the composition of the present invention is as follows. That is, a base plate that is fixed near the X-ray emission port and has an X-ray passage port and one surface of the base plate is rotated around the X-ray passage port at equal intervals through the first fulcrum pin. A plurality of movably arranged first leaves and a plurality of first leaves that are directly or indirectly overlapped with each other with a phase shift in the circumferential direction with respect to the first leaves, and are arranged at equal intervals around the X-ray passage opening. A plurality of second leaves rotatably arranged via a fulcrum pin, first and second guide pins protruding from the first leaf and the second leaf, and an X-ray passage opening of the base plate. And an operating ring that is concentrically rotatable and that has a groove or hole that engages with the first and second guide pins.

[0006]

[Action]

 When the operating ring is rotated, the leaf moves inward and outward in the radial direction together with the guide pin as the cam groove moves, and the aperture of the throttle changes. During operation, the adjoining gaps of the first leaf are covered by the second leaf, always maintaining the correct shaped opening.

[0007]

【Example】

 An embodiment of the present invention will be described below based on an embodiment shown in the drawings.

2 and 3, the base plate 1 is fixed near an X-ray emission port (not shown) and has a pin moving hole 1b around the X-ray passage port 1a. The base plate 1 is made of a square lead plate, and the round X-ray passing port 1a is provided at the center thereof, and eight round pin moving holes 1b are provided on the concentric circle at equal intervals.

On one surface of the base plate 1, four first leaves 2 are rotatably arranged around the X-ray passage opening 1a at regular intervals via first fulcrum pins 4. These first leaves 2 are made of a thin plate of lead, and are fastened at the ends by a first fulcrum pin 4 to form an opening edge 2a and a boundary edge 2b which form 90 degrees with each other at the tip end portion thereof. The shape becomes a square contour.

The phase of the X-ray passage opening 1a in the circumferential direction is shifted by 45 degrees with respect to the first leaf 2, and the four second leaves 3 are indirectly laminated via the partition plate 10 with less friction. . These leaves 3 are rotatably arranged around the X-ray passage port 1a at equal intervals via a second fulcrum pin 5. And these 2nd leaf 3 is comprised similarly to the said 1st leaf 2. As a result, the opening edges 2a and 3a form a regular octagon as a whole.

First and second guide pins 6 and 7 are projectingly provided from the first leaf 2 and the second leaf 3 to the base plate 1 side, penetrate the pin moving hole 1b, and Project to the other side.

A bearing ring 8 is fixed concentrically to the X-ray passage port 1 a of the base plate 1, and an operation ring 9 is rotatably attached to the bearing ring 8, and the operation ring 9 is connected to the first and second guide pins 6 a and 6 b. , 7 to engage with the cam groove 9a. Driving teeth 9b are provided on the outer circumferential surface of the operation ring 9, and a pinion (not shown) and a motor are connected thereto.

Here, the cam groove 9a is formed in an arc shape so that the rotation angle of the ring 9 and the opening amount (diameter) of the leaves 2 and 3 are in a slightly proportional relationship.

The operation state will be described above. The diaphragm is a regular octagonal opening, and the fully open state is shown in FIG. Next, when the operation ring 9 is rotated via the teeth 9b (clockwise in FIG. 2), the leaves 2 and 3 move inward in the radial direction together with the guide pins 6 and 7 as the cam groove 9a moves, and The opening degree of is decreased (shown in FIG. 2). In the fully closed state, as shown in FIG. 5, the leaf opening edges 2a and 3a and the boundary edges 2b and 3b contact each other. During the above operation, the adjacent gaps of the first leaves 2 are covered with the second leaves 3, and the regular octagonal opening is always held.

The partition plate 10 can be omitted. The number of first and second leaves is not limited to four each, and a plurality of two or more is applied.

As shown in FIGS. 6 and 7, the operation ring 9 may be provided on the second leaf 3 on the opposite side of the base plate 1. That is, the operation ring 9 is provided with a plurality of arc slits 9c (three in the figure) at substantially equal intervals on a circle concentric with the center of rotation. Then, these slits are fitted to the fulcrum pins 4 and 5 via the roller 11. The first and second guide pins 6 and 7 project from the first and second leaves 2 and 3 toward the operation ring and fit into the cam hole 9a. As a result, the operation ring 9 is rotated by the guide of the arc slit 9c and the roller 11. In this case, the bearing ring 8 and the pin moving hole 1a of the base plate 1 are unnecessary. Further, in the embodiment of FIGS. 2 and 3, if the X-ray passage opening 1a of the base plate 1 is enlarged beyond the moving range of the guide pins 6 and 7, the separate pin moving hole 1a becomes unnecessary.

Further, in FIGS. 6 and 7, if a thin base plate 1 with less friction is used instead of the partition plate 10, the separate partition plate 10 can be omitted. Pin moving holes may be required in the base plate 1.

The present invention is not limited to the above-described embodiments and embodiments, and includes various modifications without departing from the spirit and scope of the utility model registration request.

[0019]

[Effect of device]

 With the configuration of the present invention, the diaphragm can be made compact, and the distance between the leaf and the focal point is substantially constant, so that there is very little variation in the sharpness of the leaf edge on the image receiving screen of the image receiving device.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the prior art.

FIG. 2 is a front view of an embodiment of the present invention.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an operation explanatory diagram.

FIG. 5 is an operation explanatory view.

FIG. 6 is a front view of another embodiment of the present invention.

7 is a sectional view taken along line VII-VII of FIG.

[Explanation of symbols]

 1 ... Base plate 1a ... X-ray passage port 1b ... Pin moving hole 2 ... First leaf 3 ... Second leaf 4 ... First fulcrum pin 5 ... Second fulcrum pin 6 ... First guide pin 7 ... Second guide pin 8 ... Bearing ring 9 ... Operating ring 9a ... Cam groove 9b ... Tooth 10 ... Partition plate

Claims (1)

[Scope of utility model registration request] 1. A base plate fixed in the vicinity of an X-ray emission port and having an X-ray passage port;
A plurality of first leaves rotatably arranged at equal intervals around the line passage opening via first fulcrum pins and directly or indirectly overlapped with the first leaf by shifting the phase in the circumferential direction. And a plurality of second leaves rotatably arranged around the X-ray passage opening via a second fulcrum pin, and a first leaf projecting from the first leaf and the second leaf. And a second guide pin, and an operation ring concentrically rotatable with respect to the X-ray passage opening of the base plate and having a groove or hole that engages with the first and second guide pins. X-ray diaphragm device.