JPH08271696A - Manufacture of collimator for radiation detector - Google Patents

Abstract

PURPOSE: To makes it possible to manufacture a collimator for a radiation detector in a simple and easy way and with high precision and reduce the costs in manufacturing it. CONSTITUTION: First, a jig 3 is placed in a prescribed position of a supporting plate 1. Then, an adhesive 6 is applied to one of shielding plates 4, which are inserted into grooves 5, slid to the bottom and glued to the supporting plate 1. This work is repeated as many times as the number of the grooves 5. After inserting the shielding plates 4 into all the grooves and gluing them to the supporting plate 1, an opening scooped out in the jig 3 is covered from above with a supporting plate 2, which is glued with an adhesive 7 to each of the shielding plates 4 already inserted into the grooves 5 and the jig 3 is pulled out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a collimator for a radiation detector used for X-ray CT or the like.

[0002]

2. Description of the Related Art For example, in an X-ray CT apparatus, as shown in FIG. 7, X-rays emitted from an X-ray tube 31 are transmitted through an object 32 and a collimator 33 removes unnecessary scattered X-rays. The detector array 34 arranged in an arc shape detects and forms an image.

As shown in FIG. 8, the collimator 33 is composed of support plates 35 and 36 and a shield plate 38 which constitutes a collimator, and the shield plate 38 is inserted along a groove portion 37 provided in the support plates 35 and 36. It is fixed.

In this collimator 33, a shield plate 38 is inserted corresponding to the opening of each detector so that the transmitted X-rays can be accurately detected by each detector of the detector array 34.

The X-rays that have passed through the spaces partitioned by the shield plate 38 are detected by the detector array 34.

[0006]

By the way, conventionally, when manufacturing the collimator 33, the grooves 37 having the thickness of the shield plate 38 are made to correspond to the number of detectors in the two support plates 35 and 36. Make a cut, make these two plates 35, 36 face each other, and put one in the cut groove,
A single collimator was formed by inserting the shield plate 38 and adhering and fixing it.

However, according to this method, in order to manufacture one collimator, grooves are formed in the supporting plates for each of the necessary number of shielding plates, and then these supporting plates are opposed to each other to form one shielding plate. Since it is necessary to insert and bond them one by one, the manufacturing process takes time, and the positioning of the plates is not easy, which deteriorates the pitch accuracy of the shielding plate and increases the cost.

The present invention was devised to solve the above problems, and provides a method of manufacturing a radiation collimator which can be manufactured simply and quickly with high accuracy and at low cost.

[0009]

In order to achieve the above object, a method of manufacturing a radiation collimator according to the present invention is a method of manufacturing a collimator by stacking a large number of radiation shielding plates at predetermined minute intervals. In addition, a radiation shielding plate precut into a jig frame body having a hollow space having a shape along the entire outer shape of the collimator, and having a plurality of vertical grooves into which the side portions of the plate can be fitted along the inside of this space. Is inserted in the vertical direction along the groove, the upper and lower surfaces of each plate are integrally adhered to the support plate, respectively, and then the upper and lower surfaces of the plate are pulled out to either one of the upper and lower sides.

Further, the width of the support plate is narrower than the length of the radiation shield plate in the height direction.

The hollowed-out space of the jig frame is formed in a shape that conforms to the entire outer shape of the collimator, and a vertical groove into which the side surface of the shield plate can be fitted is provided inside the space. , The shield plates are inserted into the groove one after another, and after the required number of sheets have been inserted, the upper and lower surfaces of these shield plates are integrally bonded to the respective support plates, and the jig frame, the support plate and the shield plate are integrally formed. By separating and, a collimator for the radiation detector can be manufactured.

As described above, since it is only necessary to insert the shielding plate into a jig in which the positional relationship of the shielding plate is predetermined and adhere the same, it is possible to easily manufacture a large number of highly accurate collimators and reduce the cost.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a manufacturing process of a collimator according to the present invention, and FIG. 2 shows a state in which bonding is completed.

1 is a support plate made of stainless steel or the like,
2 is an arc-shaped support plate made of stainless steel or the like, 3 is a jig whose inside is hollowed out, 4 is a shield plate which is made of a substance having a large atomic number such as tungsten or tantalum, and shields radiation, and 5 is a jig 3 It is a groove formed in.

The hollow portion of the jig 3 is hollowed out by wire electric discharge machining or the like into an arc shape which forms a part of an arc centered on the point P so as to follow the entire outer shape of the collimator. Grooves 5 are formed in the inner part of the arcuate portion after the bending so as to face each other.

The groove 5 is formed in conformity with the width of the side surface of the shield plate 4 so that the shield plate 4 can be inserted from above, and is formed in a strip shape at a predetermined pitch corresponding to the number of detectors.

The support plate 2 has an arcuate shape so as to fit within the hollowed-out portion of the jig 3 so as to form a part of an arc centered at the point P, and the area of the hollowed-out portion is larger than the area of the hollowed-out portion. It's a little smaller.

Next, a method of manufacturing the collimator will be described.

First, the jig 3 is arranged at a predetermined position on the support plate 1 and the position thereof is prevented from being displaced by a fixing pin or the like.

Next, an adhesive 6 is applied to the surface of the shield plate 4 that has been cut into a predetermined size in advance when it is inserted into the groove 5, that is, the surface contacting the support plate 1, that is, the lower side surface of the plate 4. Is inserted into the groove 5 and is slid to the bottom to adhere to the support plate 1. This operation is repeated for the number of grooves 5.

After inserting the shielding plates 4 into all the grooves and adhering them to the supporting plates 1, the supporting plates 2 are covered from above onto the hollowed-out openings of the jig 3, and the shielding plates 4 that have already been inserted are covered. Adhesive 7 is applied to the upper surface.

FIG. 2 is a sectional view showing a state in which all the fixing is completed in this way. Here, the collimator is completed by pulling out the jig 3 to the upper side. The radiation incidence direction of the completed collimator is the direction shown in FIG. 3, and there is an empty space of the plate 1 on the side opposite to this radiation incidence direction, but a sensor array (solid-state detector array, etc.) is attached here. To be

In the above embodiment, the shield plate 4 is adhered to the support plate 1 and then the support plate 2 is adhered to pull out the jig 3. However, the shield plate 4 is inserted into the groove 5 of the jig 3. After the insertion, the support plates 1 and 2 are adhered, and then the jig 3 and the support plates 1 and 2 are attached.
Alternatively, the shield plate 4 may be separated from the integrated body.

Since the jig is integrally formed as described above, it is possible to improve the accuracy of the arrangement pitch of the shield plates. If this jig is repeatedly used, a groove is cut in the support plate. Since it is not necessary to assemble, a large number of collimators can be easily manufactured, and the cost can be reduced.

FIGS. 3 and 4 show another embodiment.

The width W of each of the support plates 12 and 13, which is a part of the collimator member, is the height of the collimator (shield plate 1
4 height) h.

First, the jig frame body 15 is arranged at a predetermined position of the bottom plate jig 11 so that the positioning pin 21a does not shift the position, and the support plate 13 is attached to the jig frame body 1.
Insert it into the hollowed-out part of No. 5 so that the positioning pin 21b does not shift the position.

Next, when the shield plate 14 which has been cut to a predetermined size is inserted into the groove 19, the support plate 1
3, the adhesive 20a is applied to the surface contacting with 3, that is, the lower surface of the plate 14, the shielding plate 14 is inserted into the groove 19 and slid down, and the adhesive 20a is applied to the support plate 13.
Glue with. This operation is repeated for the number of grooves 19.

Insert the shield plate 14 into all the grooves,
After adhering to the support plate 13, the positioning jig 18 is set and fixed by fitting the pin hole 17 into the reference pin 16, and the support plate 12 is moved upward so as to abut the lateral surface and the front surface of the positioning jig 18. Then, the jig frame body 15 is covered with the hollowed-out opening, and the upper surface of each of the shielding plates 14 already inserted is bonded with the adhesive 20b.

When all the fixing is completed in this way, the state shown in FIG. 4 is obtained. Here, the collimator is completed by pulling the jig frame 15 upward or the support plate 13 together with the bottom plate jig 11 downward.

FIG. 5 shows an example of a detector block constituted by using the collimator manufactured as described above. Complete the collimator with main plate A and main plate B
The wiring board 23 having the scintillator 22 for detecting radiation is sandwiched between the sensor fixing screw 27a and the wiring board 23.
It is fixed to each of the main plate A and the main plate B by. The positional relationship with the main plate is determined by the positioning pin 30.

In general, a detector array such as an X-ray CT is divided into, for example, about three detector blocks for the sake of simplification of production, and after these are individually manufactured, three detectors are produced. The blocks are assembled into one detector array.

The main plate A and the main plate B have a length corresponding to these three blocks and are formed in an arc shape. After the detector blocks are arranged, they are fixed to the mother base 24 with fastening bolts 27b. In addition, the scintillator 22
The signal detected at passes through the flexible cable 26,
A signal is sent to a DAS (data acquisition system) via the connectors 29a and 29b. The entire detector is covered with a light-shielding cover 25 to block outside light, and a sponge 28 closes the gap. Figure 6
Indicates adjustment between detector blocks. For convenience, only the collimator part is shown. The collimator center 43, which is a constituent part of the center of the collimator, is bolted with the positioning pin 30 on the main plate A and the pin hole on the support plate 13 fitted together. On the other hand, the collimator light 44, which is the right block, is in a free state. A block 40 is fastened to the end of the main plate A of the collimator light 44, and a screw hole is formed perpendicularly to the side surface of the block 40, and an adjusting bolt 42 is passed through the screw hole.

By rotating the adjusting bolt 42, the pushing plate 41 bridged between the support plates 12 and 13 is pushed to finely adjust the position of the collimator light 44, and the collimator light 44 is positioned and fastened by a jig or the like. The block 40 is fastened as a spacer between the main plates A and B and constitutes a part of the detector.

The collimator formed by the method of manufacturing the collimator of FIGS. 3 and 4 is different from the collimator formed by the method of FIGS.
Since the width W of 13 is shorter than the height h of the shield plate, the scintillator 22, the sensor part such as the wiring board 23 can be directly mounted on the collimator as shown in FIG. Since both ends of 14 are exposed from the support plates 12 and 13, the arrangement position of the shield plates can be inspected by the three-dimensional projector.

[0037]

As described above, according to the collimator manufacturing method of the present invention, since the jig having the groove for inserting the shielding plate in advance is formed in the hollow portion,
It is possible to increase the precision of the arrangement pitch of the shielding plates,
A large number of collimators can be manufactured easily and quickly.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a collimator for a radiation detector according to an embodiment of the present invention.

FIG. 2 is a diagram showing a collimator of the radiation detector in a state where the bonding work is finished.

FIG. 3 is a diagram showing a manufacturing process of the collimator of the radiation detector according to another embodiment of the present invention.

FIG. 4 is a view showing a collimator of the radiation detector in a state where the bonding work is finished by the manufacturing method of FIG.

FIG. 5 is a diagram showing an example of a detector block configured by using the collimator of FIG.

FIG. 6 is a diagram showing a method of aligning a collimator.

FIG. 7 is a diagram showing a schematic configuration of an X-ray CT apparatus.

FIG. 8 is a diagram showing a configuration of a collimator of a conventional radiation detector.

Claims (2)

[Claims] 1. A method of manufacturing a collimator in which a large number of radiation shielding plates are laminated and arranged at a predetermined minute interval, and a hollow space having a shape along the entire outer shape of the collimator is provided, and the hollow space is formed along the inside of this space. A plurality of pre-cut radiation shielding plates are vertically inserted along the grooves into a jig frame body having a large number of vertical grooves into which the side portions of the plates can be fitted, and the upper and lower surfaces of each plate are respectively supported by support plates. A method for manufacturing a collimator for a radiation detector, comprising: integrally bonding the same to the above, and then pulling it out from the frame body to one of upper and lower sides. 2. The method for manufacturing a collimator for a radiation detector according to claim 1, wherein the width of the support plate is narrower than the length of the radiation shielding plate in the height direction.