Object manipulator for x-ray inspection system

Abstract

To provide an object manipulator for an X-ray inspection system.SOLUTION: An object manipulator includes an object stage 6 on which a test object can be secured, a first linear guide along which the object stage can be moved in a first direction, and a second linear guide along which the object stage can be moved in a second direction, the second direction being perpendicular to the first direction. An object stage interface 10 is formed on the first linear guide. In an interface region 8, the object stage is detachably connected to the object stage interface via a connecting device. In a support region, the object stage is arranged on the first linear guide to be positionally movable thereon. The support region is formed separate from the interface region, locally at its end facing the interface region.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an object manipulator for an X-ray inspection system including an object table capable of fixing an object to be tested.

Background Art

[0002] In non-destructive inspection of a test object using X-rays, use of an X-ray system using an X-ray tube and an X-ray detector as an imaging system is involved. The test object to be inspected can be placed in the beam path and needs to be movable within the beam path. To enable this movement, the test object is attached to a manipulator capable of linearly moving the test object along various different lateral axes and rotating it about various different rotation axes, where the respective required directions and rotation axes depend on the procedure to be performed (for example, rotational laminography). In the object manipulators used to date, an object table capable of fixing the test object is placed on a thin object table support. This thin object table support cannot be manufactured with high precision. Furthermore, the object table support bends under a high load. Due to both of these factors, the object table cannot be stably positioned, or cannot be properly aligned with the lateral axis, the rotation axis, and the central beam of the X-ray source. The object table is usually positioned using two pins in holes in the object table support. Depending on the tolerance of the pins or the holes into which the pins are inserted, the object table may move when the axis is moved on the object table support. When the object table is replaced or repositioned, the position of the object table may change. For this reason, sufficient positioning reproducibility cannot be achieved, and adjustment of the object table with respect to the lateral axis and the rotation axis of the X-ray inspection system, or with respect to the central beam, becomes complicated. Also, the same applies because the degree of deflection of the object table support is different for test objects of different weights.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide an object manipulator with improved positioning reproducibility after replacing an object table.

Means for Solving the Problems

[0004] According to the present invention, the above problems are solved by an object manipulator having the features of claim 1. Advantageous embodiments are described in the dependent claims.

[0005] The above problem is solved by an object manipulator according to the present invention, the object manipulator having an object table and first and second linear guides along which the object table (6) is movable in two directions (which are typically selected to be perpendicular to each other and are referred to as the X direction and the Z direction), an object table interface being formed on the first linear guide, the object table having an interface region within which the object table is removably connected to the object table interface via a connection device, the object table having a support region within which the object table is disposed on the first linear guide so as to be positionally movable thereon, and the support region being spatially separated from the interface region, preferably the support region being formed at an end opposite to the interface region. Thereby, instead of the conventional thin object table support that was not able to obtain good reproducibility with various weights of test objects placed on various different object tables due to a tendency to bend, an object table that is significantly dimensionally more stable than the object table support and is supported on the first linear guide without interposing the object table support is provided, whereby the positioning repeat accuracy when changing or replacing the object table is optimized. Further, unlike the manufacture of the conventionally used object table support, it becomes possible to manufacture the object table with high precision.

[0006] According to an advantageous development of the invention, the first linear guide has two parallel guide rails and / or the second linear guide has two parallel guide rails, in particular it being provided that the guide rails are circular or rectangular linear shafts. This means that there is no need to use the linear guides known from the prior art which need to be manufactured as expensive production parts, and instead a more cost-efficient solution in the form of purchased parts can be used.

[0007] According to another advantageous development of the invention, the connecting device has two screws, in particular two clamping screws, and it is provided that the two screws interact with the object table interface and the interface region. Thereby, it is achieved that the exchanged object table is positioned very reliably and accurately at the position where the previous object table was located. Therefore, the repeated positioning accuracy is very high, and an undesired change in the relative position of the object table with respect to the first linear guide cannot occur.

[0008] According to yet another advantageous development of the invention, the connecting device has first stopping means and third stopping means on the object table interface, and second stopping means and fourth stopping means on the interface region, and it is provided that the second stopping means is pressed against the first stopping means and the fourth stopping means is pressed against the third stopping means by a pressing device. Since the stopping means cannot be moved by the pressing device within a plane extending in the first and second directions of the two linear guides (which is usually referred to as the X-Z plane of the object manipulator), as in the embodiment described in the previous paragraph, it is achieved that the exchanged object table is positioned very reliably and accurately at the position where the previous object table was located. Therefore, also in the embodiment described in this paragraph, the repeated positioning accuracy is very high.

[0009] According to yet another advantageous development of the present invention, the first stop means and the third stop means are each a linear shaft or a cylindrical pin extending substantially perpendicular to the first direction and the second direction, the second stop means is a linear stop edge extending along the first direction, and the fourth stop means has a body having a first stop surface and a second stop surface, and the respective orientations of the first stop surface and the second stop surface have a direction component not parallel to the stop edge, one direction component having a positive angle with respect to the second direction and the other direction component having a negative angle with respect to the second direction, and in particular, it is provided that the angle between these two orientations is 90°. Thereby, it is ensured that the replaced object table is accurately and repeatably positioned using very simple means and the system is not overdetermined, so that the replaced object table fits precisely on the intended contact surface. The force of the pressing device presses the object table with the contact edge and the two stop surfaces against the linear shaft or the cylindrical pin, thereby making it impossible for the object table to move in the direction of the plane spanning the two linear guides (the X-Z plane of the object manipulator as described above).

[0010] According to yet another advantageous development of the present invention, at least one of the linear shafts or at least one of the cylindrical pins is relatively movable in a direction having a component in the second direction with respect to the object table interface, and / or the linear stop edge is movable in a direction having a component in the second direction. For example, when the linear shaft or the cylindrical pin interacting with the contact edge is moved, the object table rotates around the other linear shaft or the other cylindrical pin, and the same is true when the stop edge is moved accordingly. This corresponds to a rotation around the Y direction, i.e., a rotation around a direction perpendicular to the plane spanning the object table, when the normal direction designation (see above) is adopted. Such a rotation enables alignment of the contact edge with the horizontal rotation axes around the first direction (usually the X direction) and the second direction (usually the Z direction).

[0011] According to yet another advantageous development of the present invention, the pressing device comprises a spring having a force component along a second direction, and in particular, it is provided that the pressing device is a side pressure piece. Such an implementation is particularly simple and possible by using means already available on the market.

[0012] According to yet another advantageous development of the present invention, it is provided that the manipulator has both a connection device in the form of two screws and a connection device with first to fourth stopping means. Thereby, the respective advantages of the above-described embodiments are combined.

[0013] According to yet another advantageous development of the present invention, two shaft receivers, in particular rotating wheels, are arranged on the object table interface, and the two shaft receivers support the object table interface to move along a first direction together with the object table, and at least one of the two shaft receivers, preferably both of the two shaft receivers, is movable in a third direction having both a component perpendicular to the first direction and a component perpendicular to the second direction, and preferably, the third direction is perpendicular to the first direction and the second direction. When both shaft receivers are adjusted equally, rotation around the first direction (usually the X direction) occurs. When only one of the shaft receivers or the two shaft receivers are adjusted differently, rotation around the second direction (usually the Z axis) occurs. This is only a minimal change in height and actually has very little effect, but this second rotation does not occur exactly around this second direction. Instead, due to the torsion of the object table, as a result, rotation around a straight line parallel to the Z axis occurs. In addition to the rotating wheels described above as possible shaft receivers, any other known shaft receivers can also be used, and sliding bearings are also possible instead of rolling bearings, and in that case, known sliding bodies can be used as the bearing body.

[0014] According to yet another advantageous development of the present invention, it is provided that at least one of the two shaft receivers is movable via an eccentric device. Such an embodiment can be adjusted very finely using commercially available tools.

Brief Description of the Drawings

[0015] Hereinafter, further details and advantages of the present invention will be described by referring to the exemplary embodiments shown in the drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0016] FIG. 1 shows a schematic example of the structure of an X-ray inspection system. The system has an X-ray tube 2 that emits an X-ray beam (not shown) and an X-ray detector 3 that faces the X-ray tube 2 and detects the X-ray from the X-ray source 2. A manipulator 1 is disposed between them, and a test object 22 (see FIG. 3) irradiated by the X-ray beam can be fixed to the manipulator 1. The possibility that the X-ray tube 2 and the X-ray detector 3 move is not essential for the present invention, and thus is not shown.

[0017] A Cartesian coordinate system is specified, and its orientation corresponds to the normal convention, although different orientations are also possible. The Y-axis extends perpendicular to the direction of the X-rays emitted from the X-ray tube 2. The Y-direction and the Z-direction extend parallel to a plane spanning the surface of the object manipulator 1. Regarding the present invention, the possible movements (linear and rotational movements) of the object table 6 (see FIGS. 5 to 8) are shown. They are linear movements parallel to the X-axis (referred to as XO), the Y-axis (referred to as YO), and the Z-axis (referred to as ZO), and rotational movements around axes parallel to the X-axis (referred to as XOR), the Y-axis (referred to as YOR), and the Z-axis (referred to as ZOR).

[0018] FIG. 2 shows a perspective view of the inventive structure of the object manipulator 1 according to the present invention. This structure extends in a plane substantially parallel to the XZ plane (excluding the height in the Y-direction). In the description of FIG. 2, the functions of the illustrated components and how they interact have not yet been fully described, but this will be further described later in the descriptions of the other figures.

[0019] The lowermost layer of the manipulator 1 forms a second linear guide 5, and this second linear guide 5 has two parallel guide rails, namely, a third guide rail 5a and a fourth guide rail 5b. On this second linear guide 5, a first linear guide 4 is arranged, and this first linear guide 4 has two parallel guide rails, namely, a first guide rail 4a (in the form of a profile rail 4a) and a second guide rail 4b (in the form of a round linear shaft 4b). The guide rails 4a, 4b of the first linear guide 4 are arranged perpendicular to the guide rails 5a, 5b of the second linear guide 5.

[0020] On the first linear guide 4, an object table 6 that is movable along the first and second guide rails 4a, 4b is arranged. One end of the object table 6 (hereinafter referred to as the support region 9) is placed on the second guide rail 4b via a shaft receptor that is not specified in more detail and not shown. The end on the side away from the support region 9 (hereinafter referred to as the interface region 8) is removably connected to the object interface 10. This connection is realized through a system of two clamp screws 14, 15, four stop means 12, 13, 16, 17, and a pressing device 23 (the details of this and the interaction of these components will be described later in connection with FIGS. 4 and 5 below). A recess 7 (for example, circular) is formed in the object table 6, and a test object 22 (see FIG. 3) can be fixed in this recess 7.

[0021] The object table interface 10 is movably connected to the second guide rail 4b via shaft receptors 20, 21 shown in FIGS. 6 and 8. The object table interface 10 has a step 11 in its vicinity (the right side in FIG. 2), and the interface region 8 of the object table 6 is placed on this step 11. The first and third stop means 12, 13 are attached to the object table interface 10, and the second stop means 16 and the fourth stop means 17 are attached to the object table 6.

[0022] Figure 3 shows a highly schematic cross-section parallel to the YZ plane of the object manipulator 1. The object table 6 is placed on two guide rails 4a, 4b extending perpendicular to the plane of the paper. This is done directly in the support area 9 and via the object table interface 10 in the interface area 8. To ensure that the object table 6 is stationary relative to the object table interface 10, these two parts are connected by two clamp screws 14, 15. This prevents relative movement between the object table 6 and the object table interface 10, and thus also between the first linear guide 4 and the second linear guide 5 of the object manipulator 1. Regardless of the type of object table 6 installed in the manipulator after replacement, the position of the object table 6, and thus the position of the test object 22 fixed in its receiving recess 7, is accurately determined. Therefore, during the X-ray inspection of the test object 22, inaccuracies / errors in reconstructing the test object 22 from the data obtained during the X-ray inspection do not occur due to positioning inaccuracies. This allows for easy replacement of the object table, eliminating the need to readjust the object manipulator 1 after this replacement. Below the object table 6, an X-ray tube 2 that is movable relative to the object table 6 is shown.

[0023] Unlike the prior art that employs a circumferential object table support that contacts both guide rails 4a and 4b into which the object table 6 is inserted, the above advantages are achieved by using only one object table interface 10 that interacts on one side with the first guide rail 4a of the first linear guide 4, in combination with the direct interaction between a part of the object table 6 (its support region 9) and the second guide rail 4b of the first linear guide 4. Unlike the object table support made of a thin metal plate that has been conventionally used, the solid object table 6 can be manufactured with high precision. Due to its solid design, unlike the use of a conventional object table support, even when test objects 22 of different weights are used, it will not bend in the Y direction.

[0024] Figure 4 shows, in a plan view (from the direction opposite to the Y direction), a part of the object table 6 in the interface region 8 connected to the table interface 10. In addition to the two clamp screws 14, 15 that prevent relative movement between the object table 6 and the object table interface 10 after the accurate alignment of the object table 6 in the object table interface 10, which was described in more detail above, the accurate alignment is made possible by an additional structure.

[0025] This structure is achieved by combining four stopping means 12, 13, 16, 17 with a pressing device 23, and its effect is indicated by an arrow of force represented by F. The pressing device 23 presses the object table 6 in the left direction against the fixed object table interface 10 (for example, by a spring force), so that the second stopping means 16 contacts the first stopping means 12 and the third stopping means 17 contacts the second stopping means 13. For example, a side pressure piece can be used as the pressing device 23. When the object table 6 is inserted into the object manipulator 1 from above (that is, from the opposite direction of the Y direction) while the object table 6 is connected to the object table interface 10, the deflection of the weight force (extending in the Y direction due to gravity) of the object table 6 functions to be converted into a spring force F perpendicular to it (extending in the opposite direction of the Z direction). Due to this spring force F, the object table 6 moves in the direction opposite to the Z direction with respect to the object table interface 10 as described above, so that the stopping means 12, 13, 16, 17 spatially position the object table 6 at the object table interface 10. Instead of using the pressing device 23 with a mechanical force (such as the spring force F described above as an example), a pressing device 23 that employs pneumatic pressure or any other type can also be used.

[0026] The first and third stopping means 12, 13 formed within the object table interface 10 are embodied as a first cylindrical pin 12 and a second cylindrical pin 13 extending along the Y direction, respectively. Instead of using the cylindrical pins 12, 13, the first and third stopping means 12, 13 can be embodied as, for example, linear shafts, respectively. The second stopping means 16 is designed as a stopping edge 16, and its stopping surface is oriented parallel to the XY plane. The fourth stopping means 17 is embodied as a body having two stopping surfaces angled with respect to each other, i.e., a first stopping surface 18 and a second stopping surface 19. In the illustrated exemplary embodiment, this angle is 90°, but it is not limited thereto. Since the two contact surfaces 18, 19 extend perpendicular to the plane of the paper, the second cylinder pin 13 can interact with the two stopping surfaces 18, 19 over a longer range. The two stopping surfaces 18, 19 and the linear stopping edge 16 (in combination with the two cylindrical pins 12, 13) prevent the system from being overdetermined, i.e., it contacts in a defined manner.

[0027] Furthermore, the object table 6 can be screwed to the object table interface 10 using two clamping screws 14, 15. At this time, since the movement of the object table 6, and thus the change in position, is blocked by the two clamping screws, this screwing is useful when the force F is exceeded (for example, as a result of an additional force in the X direction).

[0028] The rotation of the object table 6 with respect to the object table interface 10 can be performed around an axis parallel to the X-axis, Y-axis, and Z-axis if necessary for adjustment.

[0029] Figure 5 shows how rotation about an axis parallel to the Y-axis is performed. Figure 5 is very similar to Figure 4, but the stop element 16 is linearly movable in the Z direction. When such movement is performed in the Z direction, the stop end 16 is moved, for example, to the right (as indicated by the arrow). Since the second cylindrical pin 13 is stationary, the object table 6 is rotated counterclockwise about the axis defined by the second cylindrical pin 13 with respect to the object table interface 10, as indicated by the curved arrow in Figure 5. This rotation about the axis enables the contact edge and the horizontal rotation axis ZOR to be aligned parallel to the linear axes XO and ZO (see Figure 1 for axis designations).

[0030] Figures 6 and 7 show how rotation about an axis parallel to the X-axis is performed. These figures are views from the opposite side of the Z direction, i.e., from the right side in Figure 2. The object table 6 extends parallel to the X-axis on a second guide rail 4b in the form of a round linear shaft 4b. The clamp screws 14, 15 and the dowel pins 12, 13, which are not relevant to this movement, can also be seen. Two shaft receivers - the first shaft receiver 20 on the right and the second shaft receiver 21 on the left - are provided so that the linear movement of the object table 6 in the X direction can be performed with as little friction as possible. Each of these shaft receivers is designed in the form of a carriage equipped with running wheels that can adjust the height - i.e., the Y direction - with respect to the object table 6. This height adjustment can be performed, for example, by an eccentric, in which case the eccentric has the same size at the two shaft receivers 20, 21.

[0031] Figure 7 is a highly schematic view of the manipulator 1 in the X direction. On the left side, the interaction of the first guide rail 4a in the form of a profile rail 4a with the object table interface 10 and the object table 6 is shown, and on the right side, the support area 9 of the object table 6 is shown moving (illustrated by arrows) due to the height adjustment by the two eccentrically operated shaft receivers 20, 21 described above. As a result, a counterclockwise rotational movement (illustrated by a curved arrow) occurs around the axis formed by the first guide rail 4a.

[0032] Figure 8 shows how the rotation around the axis parallel to the Z axis is performed. Figure 8 essentially corresponds to Figure 6. However, here the heights of the two shaft receivers 20, 21 are not changed by the same amount, and only the first shaft receiver 20 is height-adjusted with respect to the object table 6 (this is done in the same way as described above for Figures 6 and 7). As described above, this is only a slight change in height and its effect is actually very small. The second rotation is not exactly around the axis parallel to the Z direction, but due to the torsion of the object table 6, the object table 6 rotates around an axis approximately parallel to the Z direction, as shown by the curved arrow.

[0033] As shown in Figures 6 to 8, by the combination of the rotation around the axis parallel to the X axis and the rotation around the axis parallel to the Z axis, the axis of the object table 6 (here, the YOR axis shown in Figure 1) can be aligned parallel to the central beam, that is, parallel to the Y axis.

Explanation of symbols

[0034] 1 Object manipulator 2 X-ray tube 3 X-ray detector 4 First linear guide 4a First guide rail, profile rail 4b Second guide rail, linear shaft 5 Second linear guide 5a Third guide rail 5b Fourth guide rail 6 Object stage 7 Receiving recess 8 Interface area 9 Support area 10 Object stage interface 11 Step 12 First stopping means, first cylindrical pin 13 Third stopping means, second cylindrical pin 14 Clamping screw 15 Clamping screw 16 Second stopping means, stopping edge 17 Fourth stopping means 18 First stopping surface 19 Second stopping surface 20 First shaft receiver 21 Second shaft receiver 22 Test object 23 Pressing device

Claims

1. An object manipulator (1) for an X-ray inspection system, comprising: an object stage (6) on which a test object (22) can be fixed; a first linear guide (4) along which the object platform (6) is movable in a first direction; a second linear guide (5) along which the object stage (6) is movable in a second direction, the second direction having a component perpendicular to the first direction; An object stage interface (10) is formed on the first linear guide (4); the object platform (6) has an interface area (8) in which the object platform (6) is removably connected to the object platform interface (10) via a connection device; The object stage (6) has a support area (9) and is arranged on the first linear guide (4) so that the object stage (6) is positionably movable on the first linear guide (4) within the support area (9), and the support area (9) is spatially separated from the interface area (8). Object Manipulator (1).

2. An object manipulator (1) as described in claim 1, wherein the second direction is perpendicular to the first direction and / or the support area (9) is positioned at the end of the object base (6) so as to face away from the interface area (8).

3. 2. The object manipulator (1) of claim 1, wherein the first linear guide (4) has two parallel guide rails (4a, 4b) and / or the second linear guide (5) has two parallel guide rails (5a, 5b).

4. 2. The object manipulator (1) according to claim 1, wherein the connection device comprises two screws (14, 15), which interact with the object platform interface (10) and the interface area (8).

5. the connecting device has first and third stop means (12, 13) on the object platform interface (10), and second and fourth stop means (16, 17) on the interface area (8); 2. The object manipulator (1) according to claim 1, wherein the second stop means (16) is pressed against the first stop means (12) and the fourth stop means (17) is pressed against the third stop means (13) by a pressing device (23).

6. the first stop means (12) and the third stop means (13) are linear shafts or cylindrical pins (12, 13) extending substantially perpendicular to the first direction and the second direction, respectively; The second stop means (16) is a linear stop edge (16) extending along the first direction, 6. The object manipulator (1) of claim 5, wherein the fourth stop means (17) comprises a body having a first stop surface (18) and a second stop surface (19), and the orientation of each of the first stop surface (18) and the second stop surface (19) has a direction component that is not parallel to the stop edge (16), one direction component having a positive angle with respect to the second direction and the other direction component having a negative angle with respect to the second direction.

7. An object manipulator (1) as described in claim 6, wherein the angle between the orientation of the first stop surface (18) and the orientation of the second stop surface (19) is 90°.

8. 7. An object manipulator (1) as described in claim 6, wherein at least one of the linear shafts or at least one of the cylindrical pins (12, 13) is movable relative to the object base interface (10) in a direction having a component in the second direction, and / or the linear stop edge (16) is movable in a direction having a component in the second direction.

9. 6. Object manipulator (1) according to claim 5, wherein the pressure device (23) comprises a spring having a force component along the second direction.

10. An object manipulator (1) according to any one of claims 1 to 3, comprising both a connection device according to claim 4 and a connection device according to any one of claims 5 to 9.

11. two bearing bodies (20, 21) are disposed on the object stage interface (10), and the two bearing bodies (20, 21) support the object stage interface (10) moving along the first direction together with the object stage (6); 2. The object manipulator (1) of claim 1, wherein at least one of the two bearing bodies (20, 21) is movable in a third direction having both a component perpendicular to the first direction and a component perpendicular to the second direction.

12. An object manipulator (1) as described in claim 11, wherein the two bearing bodies (20, 21) are rotating wheels, and / or both of the two bearing bodies (20, 21) are movable in the third direction, and / or the third direction is perpendicular to the first direction and the second direction.

13. 13. Object manipulator (1) according to claim 11 or 12, wherein at least one of the two bearing bodies (20, 21) is movable via an eccentric device.

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