Out-of-focus ray aperture for x-ray radiator
By using disc-shaped ray forming elements and empty parts composed of X-ray impermeable materials in the X-ray tube, the separation of the X-ray beam is achieved, and the problem of scattering radiation from outside the focus in the traditional X-ray tube affecting the image quality is solved, and the image quality is improved.
Patent Information
- Application Number
- CN202411283872.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-14
- Filing Date
- 2024-09-13
- Publication Date
- 2025-03-14
AI Technical Summary
In traditional X-ray tubes, the scattered radiation from outside the focal rays occupy the share of the X-ray beam, affecting the image quality, and traditional aperture designs are difficult to effectively reduce the scattered radiation.
A disk-shaped ray forming element composed of an X-ray impermeable material is designed to form a trapezoidal cross-section through its end surface and radial side surface, and combined with at least one empty portion, the separation of the X-ray beam is achieved, forming an X-ray effective beam and measuring beam are achieved.
By separating the X-ray effective beam from the X-ray measurement beam, the share of scattered radiation in the X-ray beam is significantly reduced, thereby improving image quality.
Smart Images
Figure CN119626871A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an extrafocal beam aperture for an X-ray radiator and to such an X-ray radiator. Background Art
[0002] Conventional X-ray tubes have, in particular, an anode and a cathode, which are arranged in an evacuated housing. An electric acceleration field is typically applied between the anode and the cathode to accelerate the electrons emitted at the cathode. After being accelerated in the acceleration field, the electrons are projected onto the anode in a focal spot, in which an X-ray beam can be generated by the interaction of the incident electrons with the anode.
[0003] The accelerating field is provided in particular by an accelerating unit, which is in particular an accelerating voltage source or a radio frequency source.
[0004] Depending on the X-ray tube, the acceleration field can be designed relatively simply, especially when the distance between the anode and the cathode is relatively small. In this case, the acceleration field can be generated and switched off basically by switching the acceleration unit on and off. Generally, the more complex the X-ray tube, the more functional the acceleration unit.
[0005] For example, the acceleration unit may include a deflection unit and / or a focusing unit. The focusing unit may be designed in particular to influence the acceleration field so that the size of the focal spot on the anode, ie its diameter, length and / or width, can be changed.
[0006] The deflection unit is designed in particular to influence the acceleration field so that the position of the focal spot on the anode can be changed. In rotating anode X-ray tubes, the deflection region in which the position of the focal spot can be changed is usually significantly smaller than in rotating envelope X-ray tubes. The reason for this is that in rotating anode X-ray tubes, the cathode is usually arranged in a decentralized manner relative to the axis of rotation of the anode directly above the focal spot or above the focal track formed by the focal spot that is moved in a circular manner by the rotation of the anode. In rotating envelope X-ray tubes, on the other hand, the cathode is arranged centrally above the anode on the axis of rotation, so that the electrons emitted there must be deflected over a longer path to the decentralized focal track compared to rotating anode X-ray tubes.
[0007] In order to be able to adjust the position of the focal spot, in particular a focal spot prediction unit and / or an X-ray measuring device can be used. The X-ray measuring device is particularly aligned with the focal spot of the anode so that the focal spot can preferably be detected directly, so to speak, seen. In order for the X-ray measuring device to be able to detect the focal spot, the cross section of the X-ray beam of the anode of such an X-ray tube is usually relatively large.
[0008] The larger the cross-section of the X-ray beam, the more X-rays generated in the focal spot that strike the X-ray detector. Ideally, only an effective X-ray beam strikes the X-ray detector, which usually only includes X-rays generated in the focal spot and / or does not have scattered rays. The effective X-ray beam especially includes the portion of the X-ray beam that is imaged. In particular, such X-rays that are generated outside the focal spot by electrons that randomly strike the anode and form so-called out-of-focus rays usually negatively affect the image quality of the image reconstructed by means of X-rays detected at the X-ray detector. The reduction of the cross-section of the X-ray beam, usually by a conventional frame aperture through which the X-ray beam passes through its recessed portion, is usually not feasible or only partially feasible, because the visibility of the focal spot to the X-ray measuring device must continue to be ensured. Summary of the invention
[0009] The object underlying the invention is to specify an extrafocal beam aperture for an x-ray radiator and an x-ray radiator in which the proportion of scattered radiation in the x-ray beam can be reduced.
[0010] The object is achieved by the features of the exemplary embodiments according to the present invention. Advantageous embodiments are described in the exemplary embodiments according to the present invention.
[0011] Regardless of the grammatical part of speech of a particular term, people with either male or female gender identity are included.
[0012] The perifocal beam aperture for an X-ray radiator according to the invention has:
[0013] a disk-shaped radiation-shaping element made of a material that is opaque to X-rays,
[0014] wherein the disk-shaped beam-shaping element is designed to shape an effective X-ray beam from an X-ray beam impinging on an out-of-focus beam aperture and to additionally shape an X-ray measuring beam separately from the effective X-ray beam,
[0015] wherein the disk-shaped beam-shaping element has two opposite end faces and a radial side surface between the end faces,
[0016] wherein the cross section of the radial side surface approximately has a trapezoidal shape,
[0017] wherein the disk-shaped beam-shaping element has at least one recess for shaping the x-ray measurement beam,
[0018] At least one of the recesses has a tapering cross section.
[0019] The X-ray radiator according to the invention has:
[0020] - an X-ray tube for generating an X-ray beam,
[0021] - an extrafocal ray aperture according to the invention,
[0022] The X-ray tube has an X-ray exit window for the X-ray beam.
[0023] The extra-focal beam aperture is arranged perpendicularly to the X-ray exit window, so that the end face of the disk-shaped beam-shaping element is oriented approximately parallel to the X-ray beam.
[0024] The advantage of the out-of-focus beam aperture according to the invention is that the X-ray beam can be divided by separating the X-ray useful beam from the X-ray measurement beam. The division of the X-ray beam is particularly advantageous, since the image quality can be improved in particular as a result. Overall, scattered radiation that has a negative impact on the image quality can be reduced in particular. It is particularly advantageous to reduce the out-of-focus radiation by the out-of-focus beam aperture according to the invention.
[0025] The disc-shaped radiation-shaping element is thin in particular in the thickness direction of the radiation-shaping element. It may be advantageous to make the radiation-shaping element as thin as possible. In particular, the dimension in the thickness direction of the radiation-shaping element, in particular one of the two dimensions perpendicular to the thickness direction, is at least twice as large, preferably five times as large or a multiple of more than ten. The dimensions perpendicular to the thickness direction may be the same or different, and are in particular the longitudinal direction. The dimensions in the corresponding spatial directions may be at least partially constant or may vary.
[0026] The disk-shaped radiation-shaping element is made of a material that is opaque to X-rays. The material that is opaque to X-rays can be designed in particular to separate an effective X-ray beam from an X-ray measuring beam by attenuating the X-ray beam in sections in a region through the material that is opaque to X-rays, and the region separates the effective X-ray beam from the X-ray measuring beam.
[0027] The shaping of the X-ray effective beam and the X-ray measuring beam comprises in particular the division of the X-ray beam into two separate parts, in particular the X-ray effective beam and the X-ray measuring beam. The shaping of the X-ray effective beam and the X-ray measuring beam comprises in particular the division of the X-ray beam such that the X-ray effective beam can be detected by means of an X-ray detector and the X-ray measuring beam can be detected by means of an X-ray measuring device.
[0028] Shaping the X-ray measurement beam in addition to and separately from the X-ray effective beam means in particular that the X-ray effective beam is a first sub-X-ray beam and the X-ray measurement beam is a second sub-X-ray beam, wherein the first sub-X-ray beam and the second sub-X-ray beam are detectable and / or detectable independently of each other.
[0029] In particular, no X-ray radiation is added during the shaping of the X-ray beam. The shaping of the X-ray useful beam and the X-ray measurement beam comprises in particular attenuating a portion of the X-rays of the X-ray beam.
[0030] The shaping of the X-ray effective beam and the X-ray and / or X-ray measurement beam in particular does not include fading out of the X-ray effective beam or the X-ray measurement beam. Fading out of X-rays usually corresponds to complete absorption.
[0031] The division of the x-ray beam by the disk-shaped beam-shaping element can be performed one-to-one. Alternatively, it is conceivable that, in particular, the x-ray useful beam contains more x-rays in the x-ray beam than the x-ray measuring beam.
[0032] The X-ray-impermeable material can in particular include metal. The metal can in particular be brass, tungsten, lead and / or molybdenum. In addition to metals, the X-ray-impermeable material can in particular also include plastic. The X-ray-impermeable material can in particular be an additively manufactured material and / or a solid material.
[0033] The X-ray beam impinges in particular on the radial side surface of the disk-shaped beam-shaping element. The radial side surface has a constant dimension in particular in the thickness direction, so that the beam-shaping element has a substantially constant thickness under the condition of the cutout. Alternatively, it is conceivable that the radial side surface has an increasing dimension in the thickness direction, so that the disk-shaped beam-shaping element has, for example, a wedge shape with an angle of less than 10°. The angle can be related in particular to the distance of the out-of-focus beam aperture from the focal spot generating the X-ray beam.
[0034] The end faces of the disk-shaped radiation-shaping element extend in particular in the longitudinal direction of the disk-shaped radiation-shaping element. The end faces are oriented parallel to one another, in particular when the thickness of the radiation-shaping element is constant. Alternatively, in the case of a wedge-shaped disk-shaped radiation-shaping element, the end faces are oriented so as to converge to one another, in particular at an angle of the wedge shape. The two opposite end faces and the radial side surface therebetween delimit the volume of the disk-shaped radiation-shaping element.
[0035] The cross section of the radial side surface having approximately a trapezoidal shape means in particular that the dimension in one of the longitudinal directions of the radiation-shaping element increases or decreases, while the dimension in the other longitudinal direction of the radiation-shaping element is in particular constant. "Approximately" relates in particular to the corners of the radiation-shaping element in these two longitudinal directions. Approximately means in particular that an increase or decrease may take place in sections and / or an increase or decrease may not take place in sections. The cross section of the radial side surface is in particular perpendicular to the thickness direction of the radiation-shaping element.
[0036] The increase or decrease can be interrupted in particular by a lateral break in the beam-shaping element. The lateral break in the beam-shaping element differs from the at least one recess in particular in terms of its position and / or its function. The lateral break is in particular provided for fastening the out-of-focus beam aperture. The lateral break is in particular not exposed to the X-rays of the X-ray beam. In contrast to the lateral break, the at least one recess is exposed to the X-ray beam and / or has no effect on the increase or decrease of the beam-shaping element in one of the two longitudinal directions. The lateral break is in particular stepped.
[0037] The at least one recess usually interrupts the volume of the disk-shaped radiation-shaping element. The volume of the disk-shaped radiation-shaping element is particularly reduced by the at least one recess. The at least one recess forms a cavity in a cover defined by the two opposite end faces and the radial side surface. The volume of the at least one recess is particularly enclosed by the at least one recess and the cover.
[0038] In addition to the section with a tapering cross section, the at least one recess can have a further section with a constant cross section. The tapering of the cross section typically takes place parallel to the propagation direction of the X-ray beam. The tapering of the cross section of the at least one recess can take place in the direction in which the trapezoidal shape of the cross section of the side surface tapers or in the direction opposite to which the trapezoidal shape of the cross section of the side surface tapers.
[0039] The tapering cross section of at least one recess relates in particular to a cavity in the cover. The cavity can in particular have a wedge-shaped section. Additionally, the cavity can have a cuboid section.
[0040] The cross section of at least one recess can have an angular shape or a circular shape. In particular, the cross section can have a rectangular shape, a trapezoidal shape or a parallelogram shape.
[0041] In particular, the at least one cutout adjoins a boundary surface of the disk-shaped beam-shaping element. The at least one cutout can be designed such that the boundary surface of the disk-shaped beam-shaping element is rectangular or trapezoidal.
[0042] In addition to shaping by means of a disk-shaped beam-shaping element, the X-ray measuring beam is shaped in particular by means of at least one recess. Approximately, shaping by means of a disk-shaped beam-shaping element can be regarded as dividing the X-ray beam into an effective X-ray beam and an X-ray measuring beam and shaping by means of at least one recess for further limiting the X-ray measuring beam. Shaping the X-ray measuring beam by means of at least one recess can include attenuating the X-ray measuring beam in proportion. The at least one recess shapes the X-ray measuring beam in particular by limiting the X-ray measuring beam.
[0043] One embodiment proposes that at least one recess divides the disk-shaped beam-shaping element into two separate parts. The two separate parts are not directly connected to each other in particular physically. In the embodiment, the disk-shaped beam-shaping element is particularly implemented in two parts.
[0044] If the at least one recess does not divide the disk-shaped beam-shaping element into at least two separate parts, the disk-shaped beam-shaping element is in particular designed in one piece. In this case, the stability of the disk-shaped beam-shaping element can be advantageously increased.
[0045] One embodiment provides that the disk-shaped radiation-shaping element is designed in one piece as a segment of a block made of the same X-ray-impermeable material.
[0046] wherein the block has a tapered outer shape, wherein the radial side surface of the disk-shaped radiation-shaping element is part of the outer shape of the block,
[0047] wherein the block encloses a tapered through-hole for the effective X-ray beam,
[0048] wherein a through-hole for the useful x-ray beam and at least one recess of the disk-shaped beam-shaping element for shaping the x-ray measurement beam are separated by means of the disk-shaped beam-shaping element, and
[0049] The volume enclosed by the through-hole is at least twice as large as the volume enclosed by the at least one recess.
[0050] This embodiment is particularly advantageous because it allows for better matching of the extrafocal beam aperture to the X-ray radiator. In particular, the block of the extrafocal beam aperture can be matched to the X-ray radiator with an exact fit. In addition, the well wall of the through-well allows for a more precise definition of the X-ray active beam.
[0051] The extrafocal beam aperture has in particular a block. The block has in particular a disk-shaped beam-shaping element. In addition to the disk-shaped beam-shaping element, the block typically has a further section. In particular, the further section and the disk-shaped beam-shaping element delimit a through-well. The block, i.e. the in particular disk-shaped beam-shaping element and the further section of the block are in particular formed in one piece and / or consist of the same X-ray-impermeable material. The disk-shaped beam-shaping element and the further section are formed in one piece, for example, by means of an additive manufacturing method. An alternative method for forming the block in one piece is molding or reshaping.
[0052] The radial side surface of the disk-shaped radiation-shaping element in particular forms part of the outer shape of the block. The trapezoidal shape of the cross section of the radial side surface of the disk-shaped radiation-shaping element in particular forms part of the outer shape of the block. The trapezoidal shape of the cross section of the radial side surface of the disk-shaped radiation-shaping element preferably substantially coincides with the tapered outer shape of the block. In other words, the trapezoidal shape of the cross section of the radial side surface of the disk-shaped radiation-shaping element preferably presupposes an increase or decrease of the tapered outer shape.
[0053] The tapering through-hole has in particular a tapering cross section. The tapering through-hole is in particular completely embedded in the block. The tapering through-hole has essentially a straight extension. The block has in particular two opposite openings for the through-hole, which are arranged along a spatial direction, in particular one of the two longitudinal directions. The opening has in particular a circular or angular shape. The opening can in particular be designed in the form of a groove.
[0054] Separating the through-hole and the at least one recess by means of a disk-shaped beam-shaping element means in particular that the through-hole and the at least one recess are arranged on opposite sides of the beam-shaping element. The disk-shaped beam-shaping element is in particular arranged between the at least one recess and the through-hole.
[0055] If at least one recess divides the disk-shaped beam-shaping element into two separate parts, the block is in particular designed in a C-shaped manner. In this case, the end faces of the C-shaped block are preferably oriented toward one another in the direction of the through-hole, so that in a specific configuration, the beam-shaping element separates the through-hole from the at least one recess. In this case, the cross section of the at least one recess is in particular designed in a trapezoidal or parallelogram-shaped manner.
[0056] The volume enclosed by the through-well is in particular the volume of the through-well. The volume of the through-well is in particular enclosed by the well wall of the through-well and the opening of the through-well. The volume enclosed by at least one recess is in particular the volume of at least one recess, preferably the volume of the cavity formed by at least one recess. The volume of the through-well can be several times greater than the volume of at least one recess. The multiple can in particular be 5, 10 or 50.
[0057] One embodiment provides that the outer shape of the block is a truncated pyramid shape. In the case of a truncated pyramid shape, the cross section of the block extending perpendicularly to the length of the through-well is substantially angular, for example rectangular. Alternatively, the outer shape of the block can be a truncated cone shape. In the case of a truncated cone shape, the cross section of the block extending perpendicularly to the length of the through-well is substantially circular.
[0058] One embodiment proposes that the block has a recess for a holder for an X-ray measuring device. Advantageously, a disc-shaped radiation-shaping element is arranged between the recess and the through-well. In other words, the recess of the holder for the X-ray measuring device and the through-well are arranged on opposite sides of the disc-shaped radiation-shaping element. The recess of the holder for the X-ray measuring device is in particular cylindrical. The disc-shaped radiation-shaping element can form a side surface of the recess of the holder for the X-ray measuring device in a circumferential direction of at least 22.5°, preferably at least 90° or 360°. In the latter case, the recess of the holder for the X-ray measuring device is completely embedded in the disc-shaped radiation-shaping element and can be said to be closed. Otherwise, at less than 360°, the recess for holding the X-ray measuring device is open. The recess for holding the X-ray measuring device can be composed of a plurality of cylindrical segments, wherein the diameters of at least two of the cylindrical segments are different.
[0059] One embodiment proposes that the block has a further tapered through-well for the X-ray measuring beam, wherein the further through-well is delimited by at least one recess of the disc-shaped radiation-shaping element. The further through-well is in particular completely embedded in the block. At least one recess forms at least one well wall of the further through-well. The further through-well has essentially a straight extension. The block has in particular two further opposite openings for the further through-well, which are arranged along a spatial direction, in particular in one of the two longitudinal directions. The further opening can in particular have a circular or angular shape. The further opening can in particular be configured in a groove-like manner. The tapered through-well has in particular a tapered cross-section.
[0060] In principle, it is conceivable that the taper direction of a through-well is different from the taper direction of another through-well, in particular substantially antiparallel. Alternatively, the taper direction of a through-well may coincide with the taper direction of another through-well, in particular substantially parallel.
[0061] One embodiment provides that, in addition to the disk-shaped beam-shaping element, the block also has at least one part designed as a shell, and the part designed as a shell and the disk-shaped beam-shaping element delimit a further through-hole. In this embodiment, the out-of-focus beam aperture is designed in at least two parts. The part designed as a shell can have, in particular, a projection that reduces the volume enclosed by the at least one recess, but typically does not completely fill it. The projection and the at least one recess can, in particular, be designed to be complementary.
[0062] The X-ray tube has in particular an anode and a cathode, which are arranged in an evacuated housing. An electric accelerating field is typically applied between the anode and the cathode to accelerate the electrons emitted at the cathode. After being accelerated in the accelerating field, the electrons preferably impinge on the anode in a focal spot, in which an X-ray beam can be generated by the interaction of the incident electrons with the anode. The accelerating field is in particular provided by an accelerating unit. The accelerating unit is in particular an accelerating voltage source or a radio frequency source. The electron emitter can in particular be a thermionic emitter or a field effect emitter.
[0063] The X-ray exit window is typically part of the evacuated housing. It is conceivable that a delimited area of the evacuated housing forms the X-ray exit window, especially when the housing is made of an X-ray transparent material, such as glass. Alternatively, an X-ray transparent component can be integrated into the evacuated housing as an X-ray exit window.
[0064] The out-of-focus beam aperture is preferably perpendicular to the X-ray exit window or perpendicular to the X-ray exit window. The out-of-focus beam aperture is in particular fixedly connected to the X-ray tube. Typically, the arrangement of the out-of-focus beam aperture relative to the X-ray tube is rigid. In this case, in particular, the out-of-focus beam aperture is immovable relative to the X-ray beam. This typically results in a proportional division of the X-ray beam into an X-ray useful beam and an X-ray measurement beam that is immutable.
[0065] One embodiment provides that the X-ray tube is mounted rotatably relative to the extrafocal radiation aperture. In this case, in particular, the evacuated housing of the X-ray tube is mounted rotatably relative to the extrafocal radiation aperture. If the X-ray tube, in particular the evacuated housing, is mounted rotatably relative to the extrafocal radiation aperture, the X-ray tube is in particular a rotating housing X-ray tube.
[0066] In an alternative embodiment, the evacuated housing can be designed to be rotationally fixed relative to the extrafocal beam aperture. In this case, in particular, the anode can be mounted rotatably relative to the extrafocal beam aperture, and the X-ray tube is typically a rotating anode X-ray tube.
[0067] One embodiment provides that the X-ray source further comprises a collimator, wherein the out-of-focus beam aperture is arranged between the X-ray tube and the collimator, wherein the collimator is oriented to collimate the X-ray effective beam. The collimation of the X-ray effective beam in particular does not affect the X-ray measurement beam. The collimator can in particular comprise a rigid, i.e., non-movable and / or a dynamic, i.e., movable collimator aperture. BRIEF DESCRIPTION OF THE DRAWINGS
[0068] In the following, the present invention is described and explained in detail based on the embodiments shown in the drawings. In principle, in the following description of the drawings, structures and elements that remain essentially the same are denoted by the same reference numerals as when the corresponding structures or elements first appear.
[0069] The accompanying drawings show:
[0070] Figure 1 shows the focal extra-ray aperture according to the present invention,
[0071] Figure 2 shows the focal extra-ray aperture according to the present invention,
[0072] Figure 3 A first embodiment of an out-of-focus ray aperture is shown,
[0073] Figure 4 A second embodiment of the out-of-focus ray aperture is shown,
[0074] Figure 5 An X-ray radiator according to the invention is shown,
[0075] Figure 6 A first exemplary embodiment of an X-ray radiator is shown.
[0076] Figure 7 A third embodiment of the out-of-focus ray aperture is shown,
[0077] Figure 8 A fourth embodiment of the out-of-focus ray aperture is shown,
[0078] Fig. 9 A fifth embodiment of the out-of-focus ray aperture is shown,
[0079] Fig.10 A sixth embodiment of an out-of-focus ray aperture is shown, and
[0080] Fig.11 A seventh embodiment of an extra-focal ray aperture is shown. DETAILED DESCRIPTION
[0081] Figure 1 The perifocal ray aperture 10 according to the invention is shown from a first viewing angle.
[0082] For use not in Figure 1 The out-of-focus beam aperture 10 of the X-ray radiator 20 shown in the figure has a disk-shaped beam-shaping element 11 made of a material that is opaque to X-rays. The disk-shaped beam-shaping element 11 is designed to shape an X-ray effective beam from an X-ray beam incident on the out-of-focus beam aperture and to additionally shape an X-ray measurement beam separately from the X-ray effective beam. The disk-shaped beam-shaping element 11 has two opposite end faces 12, 13 and a radial side surface 14 between the end faces 12, 13. The cross-section of the radial side surface 14 approximately has a trapezoidal shape. The disk-shaped beam-shaping element 11 has at least one recess 15 for shaping the X-ray measurement beam. At least one recess 15 has a tapered cross-section.
[0083] The X-ray-impermeable material may comprise a metal, in particular brass, tungsten, lead and / or molybdenum. The X-ray-impermeable material may alternatively or additionally comprise a plastic. The X-ray-impermeable material may be an additively manufactured material. Alternatively or additionally, the X-ray-impermeable material may be a solid material.
[0084] Figure 2 From a second viewing angle different from the first viewing angle Figure 1 The focal point of the outer ray aperture is 10.
[0085] Figure 3 A first exemplary embodiment of an extrafocal beam aperture 10 is shown.
[0086] Figure 3 The design of at least one of the cutouts 15 is Figure 1 and Figure 2 The at least one recess 15 in the embodiment is designed differently. The at least one recess 15 divides the disk-shaped beam-shaping element 11 into two separate parts.
[0087] Figure 4 A second exemplary embodiment of an extra-focal beam aperture 10 is shown.
[0088] Figure 4 The disk-shaped beam-shaping element 11 has a first recess 15 for shaping the first x-ray measurement beam and a second recess 15 for shaping the second x-ray measurement beam. Figure 4 The embodiments basically combine Figure 2 and Figure 3 The design of at least one recess 15 in the embodiment.
[0089] Figure 5 An x-ray radiator 20 according to the invention is shown in sections in a perspective view.
[0090] The X-ray radiator 20 has an X-ray tube 21 for generating an X-ray beam and an extra-focal beam aperture 10. The X-ray tube 21 has an X-ray exit window 22 for the X-ray beam. The extra-focal beam aperture 10 is arranged perpendicular to the X-ray exit window 22, so that the end faces 12, 13 of the disk-shaped beam-shaping element 11 are oriented approximately parallel to the X-ray beam. In the exemplary embodiment, the X-ray radiator 20 has a truncated cone-shaped receiving portion.
[0091] Figure 6 A first exemplary embodiment of an x-ray radiator 20 is shown in longitudinal section.
[0092] The X-ray radiator further comprises a collimator 23. The extra-focal beam aperture is arranged between the X-ray tube 21 and the collimator 23. The collimator 23 is oriented for collimating the effective X-ray beam. In the embodiment, the X-ray tube 21 is configured as a rotating envelope X-ray tube in that the X-ray tube 21 is rotatably supported relative to the extra-focal beam aperture 10.
[0093] Figure 7 A third exemplary embodiment of an extrafocal beam aperture 10 is shown.
[0094] The disk-shaped radiation shaping element 11 is integrally formed as a segment of a block 16 made of the same X-ray-impermeable material. The block 16 has a tapered outer shape. The radial side surface of the disk-shaped radiation shaping element is part of the outer shape of the block. The block 16 surrounds a tapered through-well 17 for the X-ray effective beam. The through-well 17 for the X-ray effective beam and at least one recess 15 of the disk-shaped radiation shaping element 11 for shaping the X-ray measurement beam are separated by means of the disk-shaped radiation shaping element 11. The volume enclosed by the through-well 17 is at least twice as large as the volume enclosed by the at least one recess 15.
[0095] In the described embodiment, the outer shape of the block 16 is a truncated pyramid shape. In an alternative embodiment, it is conceivable that the outer shape of the block 16 may be a truncated cone shape.
[0096] Figure 8 A fourth exemplary embodiment of an extrafocal beam aperture 10 is shown. The block 16 has a cutout 18 for a holder of an x-ray measuring device.
[0097] Fig. 9 A fifth exemplary embodiment of an extrafocal beam aperture 10 is shown.
[0098] The block 16 has a further through-hole 19 for tapering the x-ray measurement beam. The further through-hole 19 is delimited by at least one recess 15 of the disk-shaped beam-shaping element 11 .
[0099] Fig.10 A sixth exemplary embodiment of an extrafocal beam stop 10 is shown as an alternative to the fifth exemplary embodiment.
[0100] In addition to the disk-shaped beam-shaping element 11 , the block 16 has at least one portion 16 .S which is designed as a shell. The portion 16 .S which is designed as a shell and the disk-shaped beam-shaping element 11 delimit a further through-hole 19 .
[0101] Fig.11 A seventh exemplary embodiment of an extrafocal beam stop 10 is shown in cross section.
[0102] The disk-shaped beam-shaping element 11 has two recesses 15. The block 16 is designed in the form of a truncated pyramid and is adapted to the X-ray radiator 20, which is only shown in part, in an exactly matching manner. In order to arrange the extra-focal beam aperture 10 in an exactly matching manner, the X-ray radiator 20 has a truncated pyramid-shaped receptacle in the exemplary embodiment. The extra-focal beam aperture 10 can be fastened in the receptacle in a particularly detachable manner by means of a fastening mechanism. The fastening mechanism can in particular include a plug connection, a screwing mechanism and / or an adhesive mechanism.
[0103] Although the details of the present invention have been illustrated and described in detail through the preferred embodiments, the present invention is not limited to the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of protection of the present invention.
Claims
1. An extra-focal beam aperture (10) for an X-ray radiator (20), comprising: a disk-shaped radiation-shaping element (11) made of a material that is opaque to X-rays, The disk-shaped beam shaping element (11) is designed to shape an effective X-ray beam from the X-ray beam incident on the out-of-focus beam aperture and to additionally shape an X-ray measuring beam separately from the effective X-ray beam. The disk-shaped beam-shaping element (11) has two opposite end faces (12, 13) and a radial side surface (14) between the end faces (12, 13), wherein the cross section of the radial side surface (14) approximately has a trapezoidal shape, wherein the disk-shaped beam-shaping element (11) has at least one recess (15) for shaping the x-ray measurement beam, The at least one recess (15) has a tapering cross section.
2. The out-of-focus ray aperture (10) according to claim 1, The at least one recess (15) divides the disk-shaped beam-shaping element (11) into two separate parts.
3. The perifocal ray aperture (10) according to any one of the preceding claims, The X-ray-impermeable material comprises a metal, in particular brass, tungsten, lead and / or molybdenum.
4. The perifocal ray aperture (10) according to any one of the preceding claims, The X-ray-impermeable material comprises plastic.
5. The perifocal ray aperture (10) according to any one of the preceding claims, The X-ray impermeable material is an additively manufactured material.
6. The perifocal ray aperture (10) according to any one of the preceding claims, Wherein the X-ray impermeable material is a solid material.
7. The perifocal ray aperture (10) according to any one of the preceding claims, wherein the disk-shaped radiation-shaping element (11) is designed in one piece as a section of a block (16) made of the same X-ray-impermeable material, wherein the block (16) has a tapered outer shape, wherein the radial side surface of the disk-shaped radiation-shaping element is part of the outer shape of the block, wherein the block (16) surrounds a tapered through-hole (17) for the effective X-ray beam, wherein the through-hole (17) for the effective X-ray beam and at least one recess (15) of the disk-shaped beam-shaping element (11) for shaping the X-ray measuring beam are separated by means of the disk-shaped beam-shaping element (11), and The volume enclosed by the through-hole (17) is at least twice as large as the volume enclosed by the at least one recess (15).
8. The out-of-focus ray aperture (10) according to claim 7, The outer shape of the block (16) is a truncated pyramid shape.
9. The out-of-focus ray aperture (10) according to claim 7, The outer shape of the block (16) is a truncated cone shape.
10. The perifocal ray aperture (10) according to any one of claims 7 to 9, The block (16) has a recess (18) for a holder of an X-ray measuring device.
11. The perifocal ray aperture (10) according to any one of claims 7 to 10, The block (16) has a further through-hole (19) for tapering the x-ray measurement beam, wherein the further through-hole (19) is bounded by at least one recess (15) of the disk-shaped beam-shaping element (11).
12. The perifocal ray aperture (10) according to claim 11, In addition to the disk-shaped beam-shaping element (11), the block (16) has at least one part (16.S) designed as a shell, and the part (16.S) designed as a shell and the disk-shaped beam-shaping element (11) delimit the further through-hole (19).
13. An X-ray radiator (20), comprising: - an X-ray tube (21) for generating an X-ray beam, and - an extrafocal ray aperture (10) according to any one of claims 1 to 12, wherein the X-ray tube (21) has an X-ray exit window (22) for the X-ray beam, The out-of-focus beam aperture (10) is arranged perpendicular to the X-ray exit window (22), so that the end faces (12, 13) of the disk-shaped beam shaping element (11) are oriented approximately parallel to the X-ray beam.
14. The X-ray radiator (20) according to claim 13, A collimator (23) is also provided, wherein the out-of-focus ray aperture (10) is arranged between the X-ray tube (21) and the collimator (23), wherein the collimator (23) is oriented to collimate the effective X-ray beam.
15. The X-ray radiator (20) according to claim 13 or 14, The X-ray tube (21) is supported rotatably relative to the extrafocal beam aperture (10).