JPH06304163A - Colimeter for x-ray ct - Google Patents

Abstract

PURPOSE:To provide the colimeter for X-ray CT capable of easily making the assembling with the simple structure and reducing the adjustment at the time of assembling. CONSTITUTION:A colimeter 11 for X-ray CT is provided with two sheets of blade 2a and 2b arranged almost parallel and a driving mechanism 10 which drives the blade along the opening/closing direction of the blade. The driving mechanism 10 is provided with sliding bodies 15a and 15b which slide along a guide body 14 at both ends of the blades 2a and 2b through mounting bodies 12a and 12b. The sliding bodies 15a and 15b are connected to a rotary shaft of a motor 5 through the mounting bodies 12a and 12b and a chain 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT collimator, and more particularly to a lower collimator arranged in front of an X-ray detector.

[0002]

2. Description of the Related Art An X-ray CT apparatus irradiates an examinee with X-rays while rotating the X-ray tube, and the X-rays transmitted through the examinee are converted into an X-ray tube across the examinee. The tomographic image of the subject at a predetermined slice position can be reconstructed by detecting with the X-ray detectors arranged facing each other.

An X-ray shield mechanism called a lower collimator is provided in front of the X-ray detector.

FIG. 2 shows the lower collimator 1 viewed from the X-ray tube side.

As shown in the figure, the lower collimator 1
Has two blades 2a and 2b capable of shielding X-rays arranged substantially parallel to each other.
a and 3b are attached.

In the lower collimator 1, the lead screw 4 having male threads formed on the outer circumferences of both ends is attached to the lead nut 3.
It is engaged with female threads provided on a and 3b.

Here, the male screw of the lead screw 4 is
The lead nut 3a side and the lead nut 3b side are formed in opposite directions, and when the motor 5 is rotated, the lead nuts 3a and 3b are driven in opposite directions, and the blade 2
A and 2b can be opened and closed.

In this way, the lower collimator 1 adjusts the rotation amount of the motor 5 so that the blades 2a,
The arrangement interval of 2b can be set to a predetermined interval.

[0009]

However, if the accuracy of mounting the blade is poor, the lead screw becomes slanted with respect to the center line of the lead nut, the male screw and the female screw do not engage well, and so-called bending occurs, As a result, the opening / closing operation of the blade may be hindered.

Therefore, when assembling the lower collimator, there is a problem that it takes a long time to make an adjustment.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an X-ray CT collimator which has a simple structure, is easy to assemble, and requires less adjustment during assembly. And

[0012]

In order to achieve the above object, the X-ray CT collimator of the present invention has, as described in claim 1, two blades arranged substantially parallel to each other, In a collimator for X-ray CT provided with a drive mechanism that can be driven along the opening / closing direction of the blade,
The drive mechanism includes slide bodies slidable along a predetermined guide body at both ends of the blade, and the slide bodies are connected to a rotary shaft of a motor via a predetermined transmission mechanism.

Further, in the X-ray CT apparatus of the present invention, as described in claim 2, two blades arranged substantially in parallel and a driving mechanism capable of driving the blades in the opening / closing direction of the blades. In the X-ray CT apparatus provided with the X-ray CT collimator having, the drive mechanism includes slide bodies slidable along a predetermined guide body at both ends of the blade, while the slide body is provided with a predetermined slide body. It is connected to a rotating shaft of a motor via a transmission mechanism.

[0014]

In the X-ray CT collimator of the present invention, when the blade is opened and closed, the motor is first actuated and the rotational force of the motor is converted into a linear motion force through a transmission mechanism such as a chain, rope or belt. Transmitted to the sliding body.
The sliding body that receives the direct power slides along the guide body to open and close the blade.

Here, as described in the prior art, no kinking occurs between the lead screw and the lead nut,
The slide body slides smoothly along the guide body.

[0016]

Embodiments of the X-ray CT collimator of the present invention and an X-ray CT apparatus including the same will be described below with reference to the accompanying drawings. It should be noted that parts that are substantially the same as those of the conventional technique are given the same reference numerals and description thereof is omitted.

FIG. 1 (a) is a detailed plan view of one end of the X-ray CT collimator 11 of this embodiment as seen from the X-ray tube side.
FIG. 1 (b) is a side view taken along the line AA of FIG. 1 (a).

Since the other end has almost the same structure as the above, the drawing is omitted.

As can be seen from the figure, the X-ray CT of this embodiment
The collimator 11 includes two blades 2a and 2b arranged substantially parallel to each other, and a drive mechanism 10 capable of driving these blades along the opening / closing direction of the blades.

Each of the blades 2a and 2b is made of lead or the like which can shield X-rays.

The drive mechanism 10 slides sliding bodies 15a and 15b mounted on both ends of the blades a and 2b via mounting bodies 12a and 12b along a rail 14 as a guide body formed on a frame body 13. It is configured to be movable.

A chain 16 is connected to the mounting bodies 12a and 12b, and the rotational force of the motor 5 is received as direct power via the chain 16.

In the X-ray CT collimator 11 of this embodiment, when the blades 2a and 2b are opened and closed, the motor 5 is first actuated, and the rotational force of the motor 5 is converted into a linear motion force by the chain 16 so that the mounting body is 12a, 12
b to the sliding bodies 15a and 15b.

Here, the chain 16 has, for example, a side having a large tension connected to the mounting body 12b and an opposite side mounted to the mounting body 12a.
Since the sliding bodies 15a and 15b slide on the guide body 14 in opposite directions, the blades 2a and 2b are opened and closed.

As described above, the X-ray CT of this embodiment
In this collimator, instead of the lead screw and the lead nut, the sliding bodies attached to both ends of the blade are configured to be slidable along the guide body, so even if some twist occurs between the blades after assembly. The possibility that the opening / closing operation of the blade will be hindered is reduced. Moreover, since the sliding body is driven by the chain, the driving force does not decrease even if the chain is attached to the chain, and the sliding body is reliably driven.

Therefore, there is a margin in the accuracy of assembling the collimator, the assembling becomes easy, and the adjustment at the time of assembling can be reduced, so that the assembling speed and reliability can be improved.

Further, since the deceleration by the lead screw is eliminated, the opening / closing speed of the collimator can be increased.

Further, since the backlash required for the lead screw and the nut is unnecessary, the opening / closing accuracy can be improved.

In the above-described embodiment, the mounting body is configured to be driven by the chain, but the structure is not limited to this, and a transmission mechanism such as a belt or a wire rope may be used instead of the chain. Good.

[0030]

As described above, the collimator for X-ray CT of the present invention comprises two blades arranged substantially in parallel, and a drive mechanism capable of driving the blades in the opening / closing direction of the blades. In the X-ray CT collimator provided with, the drive mechanism includes slide bodies slidable along a predetermined guide body at both ends of the blade, and the slide body is connected to a motor of the motor via a predetermined transmission mechanism. Since it is connected to the rotary shaft, it is easy to assemble with a simple structure, and the adjustment during assembly can be reduced.

Further, the X-ray CT apparatus of the present invention has an X-ray CT collimator having two blades arranged substantially in parallel and a drive mechanism capable of driving the blades in the opening / closing direction of the blades. In the X-ray CT apparatus provided with the above, the drive mechanism includes slide bodies slidable along a predetermined guide body at both ends of the blade, and the slide body rotates the motor via a predetermined transmission mechanism. Since it is connected to the shaft, it is possible to simplify the structure of the collimator for X-ray CT, facilitate the assembly, and reduce the adjustment during the assembly.

[Brief description of drawings]

FIG. 1A is a detailed plan view of one end of a collimator for X-ray CT according to the present embodiment as seen from the X-ray tube side, and FIG. 1B is a line A- of FIG.
The side view which followed the A line.

FIG. 2 is a detailed plan view of a conventional collimator for X-ray CT seen from the X-ray tube side.

[Explanation of symbols]

 2a, 2b Blade 5 Motor 11 Collimator for X-ray CT 12a, 12b Mounting body 13 Frame body 14 Rail (guide body) 15a, 15b Sliding body 16 Chain

Claims (2)

[Claims] 1. An X-ray CT collimator comprising two blades arranged substantially parallel to each other and a drive mechanism capable of driving the blades in the opening / closing direction of the blades, wherein the drive mechanism has a predetermined size. The slide body slidable along the guide body is provided at both ends of the blade, and the slide body is connected to a rotary shaft of a motor through a predetermined transmission mechanism. 2. An X-ray CT apparatus provided with an X-ray CT collimator having two blades arranged substantially parallel to each other and a drive mechanism capable of driving the blades in the opening / closing direction of the blades, The driving mechanism is provided with sliding bodies slidable along a predetermined guide body at both ends of the blade, and the sliding body is connected to a rotary shaft of a motor through a predetermined transmission mechanism. X-ray C
T device.