JP2005221460A - X-ray CT system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus which is compact and can suppress cost increase as much as possible while having functions for loading and unloading samples of various shapes.
A chucking device (6b) is provided as a handling means (6) for chucking and loading / unloading a sample (W) by a chucking device (6b) with respect to an imaging space between an X-ray source (1) and an X-ray detector (2). A rotating mechanism 6c for rotating is provided, and this handling means is configured to collect the X-ray transmission data while positioning and rotating the sample W in the imaging space, thereby moving the rotating table and the three-dimensional direction. The sample stage including the mechanism is substantially unnecessary, and a reduction in size and cost is achieved.
[Selection] Figure 1

Description

  The present invention relates to an X-ray CT apparatus for obtaining tomographic images of various industrial products.

  In an X-ray CT apparatus, in general, a sample to be measured is placed between an X-ray source and an X-ray detector that are arranged opposite to each other, and the sample is rotated, or the X-ray source and the X-ray detector are detected. The sample is irradiated with X-rays while rotating the pair of instruments around the sample, and X-ray transmission data of the sample is captured at every predetermined rotation angle. Then, a tomographic image of the sample sliced on a plane orthogonal to the rotation center axis is constructed by a tomographic image reconstruction calculation using the X-ray transmission data.

In an X-ray CT apparatus intended for an industrial product or the like, a rotating table 33a is usually provided between an X-ray source 31 and an X-ray detector 32, as schematically shown in FIG. A configuration is adopted in which W is placed on the turntable 33a to give rotation. The turntable 33a is provided with a manipulator and a chucking mechanism (not shown) for fixing the sample W on the turntable 33a, and the turntable 33a is arranged in the direction of the optical axis L (x Direction) and two directions (y and z directions) orthogonal to each other on a plane orthogonal to that direction, and a table moving mechanism 33b for moving in a total of three axial directions, and by moving the rotary table 33a in each of these directions The imaging magnification is changed, and the positioning of the sample W with respect to the field of view of the X-ray detector 32 can be performed. And the sample stage 33 is comprised by the rotary table 33a and the table moving mechanism 33b containing these manipulators etc. (for example, refer patent document 1).
JP 2003-185598 A

  By the way, in the conventional X-ray CT apparatus as described above, a sample to be subjected to measurement is carried onto the rotary table 33a, or the measured sample is carried out from the rotary table 33a to another position. When trying to automate, in order to deal with samples of various shapes, as shown in FIG. 4, a multi-axis robot 41 is used to set a predetermined sample mounting portion 42 and rotary table 33a. A method of chucking and moving the sample W between them can be considered. In FIG. 4, illustration of the X-ray source 31 and the X-ray detector 32 is omitted.

  However, according to such a configuration, in addition to the sample stage 3 composed of the rotary table 33a and the table moving mechanism 33b, an operating space for the multi-axis robot 41 is required, resulting in a large-scale apparatus. Further, according to such a configuration, the cost is increased by adding the multi-axis robot 41 to a normal X-ray CT apparatus having no sample transport function.

  The present invention has been made in view of such circumstances, and provides an X-ray CT apparatus that is compact and capable of suppressing cost increases as much as possible while having functions of loading and unloading samples of various shapes. It is an issue.

  In order to solve the above-mentioned problems, the X-ray CT apparatus of the present invention irradiates X-rays while rotating a sample by placing a sample in an imaging space between an X-ray source and an X-ray detector arranged to face each other. In an X-ray CT apparatus provided with tomographic image calculation means for reconstructing a tomographic image along a plane orthogonal to the central axis of rotation using X-ray transmission data captured at a predetermined rotational angle, Handling means for chucking a sample placed at a position by a chucking device and transferring the sample to an imaging space between the X-ray source and the X-ray detector and transferring the sample from the imaging space to another position. At the same time, the handling means includes a rotating mechanism for rotating the chucking device, and applies X-rays while applying rotation while the sample is chucked by the chucking device in the imaging space. It characterized by being configured to capture X-ray transmission data of the sample (claim 1).

  Here, in this invention, the structure (Claim 2) which makes the handling means provided with the said chucking apparatus and rotation mechanism a multi-axis robot can be employ | adopted suitably.

  The present invention is intended to achieve the intended purpose by using handling means for carrying a sample in and transporting it into an imaging space between an X-ray source and an X-ray detector as it is as a sample stage. is there.

  That is, in the present invention, the rotating table for rotating the sample and the table moving mechanism for moving the rotating table in the three-dimensional direction are eliminated, and the sample is chucked by the chucking device and is loaded into and taken out from the imaging space. The means is provided with a rotation mechanism for rotating the chucking device, and X-ray fluoroscopic data is collected by irradiating the sample chucked by the handling means with the X-ray while positioning and rotating the sample in the imaging space.

  With this configuration, it is possible to achieve a cost reduction as compared with the case of simply adding handling means, as long as the sample stage mainly composed of the rotary table and its moving mechanism is eliminated, and the sample stage should be arranged. It is possible to use the space as an arrangement position of the handling means or an operation space, and it is possible to achieve compactness.

  And as a handling means provided with the above chucking device and its rotation mechanism, it can be manufactured as a dedicated device, but as a handling means having such a function, it is provided for practical use. Multi-axis robots can be mentioned, and an experiment using a commercially available general-purpose multi-axis robot equipped with these functions yields a tomographic image that is comparable to a normal X-ray CT apparatus equipped with a sample stage. It was confirmed.

  According to the present invention, as the handling means for carrying the sample in and out of the imaging space between the X-ray source and the X-ray detector, the rotating mechanism for rotating the chucking device for chucking the sample is provided. X-ray fluoroscopic data is collected while rotating the sample chucked by the handling means in the imaging space, and the tomographic image reconstruction calculation is performed. Therefore, from a conventional rotary table and a moving mechanism for moving the same in a three-dimensional direction. There is no need to provide a sample stage, and the cost can be reduced as compared to the case where a handling means is simply added to the conventional X-ray CT apparatus so as to have a sample loading / unloading function. It is possible to use the space to be disposed as the space for disposing the handling means or as the operating space, and to achieve compactness. Door can be.

  Further, when a multi-axis robot is used as the handling means described above as in the invention according to claim 2, it is possible to achieve cost reduction by employing, for example, a general-purpose multi-axis robot provided on the market.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an embodiment of the present invention, and is a diagram illustrating a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration.

  The X-ray source 1 is arranged so that its X-ray optical axis L is horizontally oriented, and is opposed to the X-ray source 1 in the horizontal direction, for example, an X-ray camera 2 formed by combining an image intensifier and a CCD camera. Is arranged. The X-ray source 1 outputs X-rays corresponding to the tube current and tube voltage supplied from the X-ray controller 3. The output of the X-ray camera 2 is stored as X-ray transmission data in the image memory 5a of the computer 5 through the image capturing circuit 4, and is also used for the tomographic image reconstruction calculation by the reconstruction calculation unit 5b of the computer 5. The The reconstructed tomographic image is displayed on the display 8. Note that the reconstruction calculation unit 5a in the computer 5 and a control unit 5c, which will be described later, actually represent functions realized by executing programs corresponding to the respective programs installed in the computer 5. FIG. For convenience of explanation, each function is represented by a block.

  A multi-axis robot 6 is disposed adjacent to the X-ray source 1 and the X-ray camera 2. The multi-axis robot 6 includes a chucking device 6b that is appropriately replaced according to the shape of the sample W at the tip of an arm 6a having a plurality of joints, and the chucking device 6b at the center. It has a structure including a rotation mechanism 6c that rotates around an axis, and operates according to a drive control signal from the robot controller 7.

  The X-ray controller 3 and the robot controller 7 described above are connected to the control unit 5 c of the computer 5, and this control unit 5 c transmits the X-ray through the operation of the multi-axis robot 6 and the image capturing circuit 4. These are controlled so as to synchronize with the data fetching operation.

  Now, a carry-in stage 9 and a carry-out stage 10 are provided on both sides of the multi-axis robot 6, and the sample W from which a tomographic image is to be obtained is placed on the carry-in stage 9. The multi-axis robot 6 is taught in advance so as to execute the following operations.

  That is, after the sample W on the carry-in stage 9 is chucked by the chucking device 6b, the sample W is positioned at a predetermined position between the X-ray source 1 and the X-ray camera 2 and chucked in that state. The sample W is rotated together with the apparatus 6b by a set angle around a vertical axis orthogonal to the X-ray optical axis. Meanwhile, the computer 5 stores the X-ray transmission data of the sample W in the image memory 5a for each rotation angle. When the X-ray fluoroscopic data for 360 ° are finally prepared, the rotation of the chucking device 6 b is stopped and the sample W is carried out to the carry-out stage 10. The computer 5 uses the X-ray transmission data for 360 ° of the sample W stored in the image memory 5 a to reconstruct a tomographic image of the sample W by a known method in the reconstruction calculation unit 5 b and displays it on the display 8. To do.

  Of particular note in the above embodiments are mainly a rotary table for rotating the sample W to collect X-ray transmission data of the sample W and a table moving mechanism for positioning the rotary table in a three-dimensional direction. The multi-axis robot 6 is responsible for the rotation and positioning of the sample W as well as the loading and unloading of the sample W. As a result, it is possible to obtain a fully automatic type X-ray CT apparatus which is provided with a multi-axis robot 6 for loading and unloading and which is comparatively inexpensive and compact.

  Here, in the above embodiment, an example in which the sample W before obtaining the tomographic image is placed on the carry-in stage 9 and the sample after obtaining the tomographic image is carried out to the carry-out stage 10 has been shown. Without being limited thereto, for example, as schematically shown in the plan view of the main part in FIG. 2, the carry-in conveyor 21 and the carry-out conveyor 22 are arranged on both sides of the multi-axis robot 6, and are continuously carried in by the carry-in conveyor 21. It is also possible to configure so that the incoming samples W are sequentially taken out by CT, and then sequentially carried out of the apparatus by the carry-out conveyor 22.

  In the above embodiment, the example in which the multi-axis robot 6 is used to carry the sample W into the imaging space, rotate in the imaging space, and carry it out of the imaging space. The present invention is not limited to this, and a dedicated mechanism having an equivalent function may be used. In short, the X-ray is rotated in the imaging space while the sample W is chucked for loading. Any mechanism can be employed as long as it captures fluoroscopic data and carries it out of the imaging space with its chucking.

  Furthermore, in the above embodiment, the example in which the X-ray optical axis reaching the X-ray source and the X-ray camera is horizontally arranged has been shown, but the present invention is not limited to this, and the optical axis is horizontal. The direction may be slightly inclined from the direction, and the rotation axis of the sample may be left in the vertical direction. Furthermore, the X-ray optical axis may be in the vertical direction, in which case the rotation axis direction of the sample is approximately horizontal.

In the block diagram of embodiment of this invention, it is the figure which writes together and shows the schematic diagram showing a mechanical structure, and the block diagram showing an electric structure. It is a figure which shows typically the principal part top view of other embodiment of this invention. It is a principal part block diagram of the conventional X-ray CT apparatus. It is explanatory drawing of the example in the case of adding the carrying in / out function of a sample to the conventional X-ray CT apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray source 2 X-ray camera 3 X-ray controller 4 Image acquisition circuit 5 Computer 5a Image memory 5b Reconstruction calculating part 5c Control part 6 Multi-axis robot 6a Arm 6b Chucking device 6c Rotation mechanism 7 Robot controller 8 Display 9 Loading stage 10 Unloading stage W Sample

Claims (2)

Using the X-ray transmission data acquired at every predetermined rotation angle by irradiating X-rays while arranging and rotating the sample in the imaging space between the X-ray source and the X-ray detector arranged opposite to each other. In the X-ray CT apparatus provided with tomographic image calculation means for reconstructing a tomographic image along a plane orthogonal to the central axis of rotation,
Handling means for chucking a sample placed in a predetermined position by a chucking device and transferring the sample to an imaging space between the X-ray source and the X-ray detector and transferring the sample from the imaging space to another position. The handling means includes a rotation mechanism that rotates the chucking device, and irradiates the sample with X-rays while applying rotation while the sample is chucked by the chucking device in the imaging space. An X-ray CT apparatus configured to capture X-ray transmission data.   The X-ray CT apparatus according to claim 1, wherein the chucking apparatus and the handling means including the rotation mechanism are multi-axis robots.

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