Imaging optical arrangement to image an object illuminated by X-rays
An imaging optical arrangement serves to image an object illuminated by X-rays. An imaging optics serves to image a transfer field in a field plane into a detection field in a detection plane. A layer of scintillator material is arranged at the transfer field. A stop is arranged in a pupil plane of the imaging optics. The imaging optics has an optical axis. A center of a stop opening of the stop is arranged at a decentering distance with respect to the optical axis. Such imaging optical arrangement ensures a high quality imaging of the object irrespective of a tilt of X-rays entering the transfer field. The imaging optical arrangement is part of a detection assembly further comprising a detection array and an object mount. Such detection assembly is part of a detection system further comprising an X-ray source.
1 . A detection system for an X-ray inspection of an object, the detection system comprising:
an X-ray source for generating X-rays,
an object mount to hold the object,
an object displacement drive, wherein the object mount is movable relative to the X-ray source via the object displacement drive along at least one lateral object displacement direction in the object plane,
a layer of scintillator material arranged in a transfer field, wherein X-rays from the X-ray source produce a projection image on the layer of scintillator material via radiographically shading casting,
an imaging optics to image the transfer field into a detection field in a detection plane,
at least one stop being movable via a stop displacement drive, and
a control device with a drive control unit being in a signal connection with the at least one of stop displacement drive and the object displacement drive for synchronizing a movement of the stop displacement drive and a movement of the object displacement drive.
2 . The detection system of claim 1 , wherein an object side numerical aperture of the imaging optics which is defined by the stop opening is larger than 0.4.
3 . The detection system of claim 1 , wherein an angle between the X-rays entering the transfer field and an optical axis of the imaging optics is between 0 deg and 80 deg.
4 . The detection system of claim 1 , wherein the object mount and/or the at least one stop is movable along at least one linear displacement direction.
5 . The detection system of claim 1 , wherein the object mount and/or the at least one stop is movable along at least one circular direction.
6 . The detection system of claim 1 , wherein the at least one stop is configured such that the stop aperture is variable in size.
7 . The detection system of claim 1 , further comprising at least one stop exchange mount to exchange between different stops.
8 . The detection system of claim 1 , wherein no X-ray optics is present to influence a direction of the X-rays between the X-ray source and the layer of scintillator material.
9 . The detection system of claim 1 , wherein the control device has a lookup table configured to store data with respect to a dependency between actions of the stop displacement drive and actions of the object displacement drive.
10 . The detection system of claim 9 ,
wherein the control device is configured to use the data stored in the lookup table to control the stop displacement drive and the object displacement drive.
11 . The detection system of claim 1 , wherein the X-ray source is an open transmissive source or a liquid metal jet source.
12 . The detection system of claim 1 , wherein the at least one stop is a shield stop having a shield stop aperture transmissive for the X-rays, the shield stop being arranged in an X-ray path of X-rays between the X-ray source and the object mount, the shield stop being movable via the stop displacement drive along at least one displacement direction.
13 . The detection system of claim 1 , wherein the at least one stop is arranged in a pupil plane of the imaging optics and forming a pupil stop.
14 . The detection system of claim 13 , wherein a center of a stop opening of the pupil stop is arranged at a decentering distance with respect to an optical axis of the imaging optics.
15 . The detection system according to claim 14 , wherein the stop displacement drive is configured as a decentering drive to translate the pupil stop in the pupil plane.
16 . The detection system of claim 14 , wherein the decentering distance is at least 10% of a width of the stop opening.
17 . The detection system of claim 14 , wherein
a lateral displacement of the X-ray source with respect to the object mount and
the decentering distance of the center of the stop opening are balanced such that X-rays entering the transfer field run parallel to chief imaging rays of imaging light within the imaging light path.
18 . The detection system of claim 13 , wherein the stop displacement drive is configured to axially move the pupil stop.
19 . The detection system of claim 13 , wherein the imaging optics includes a movable optical element.
20 . The detection system of claim 13 , wherein the stop is an annular pupil stop.
21 . An X-ray inspection method using a detection system of claim 1 , comprising moving the stop synchronously relative to the object to be inspected to realize different object imaging projections.
22 . The X-ray inspection method of claim 21 , wherein the at least one stop is arranged in a pupil plane of the imaging optics and forming a pupil stop,
wherein a center of a stop opening of the pupil stop is arranged at a decentering distance with respect to an optical axis of the imaging optics, and
wherein the decentering distance of the stop opening of the pupil stop is adapted to an angle of an oblique or tilted entry of X-rays to the transfer field of the imaging optics.
23 . The X-ray inspection method of claim 22 , comprising balancing a lateral displacement of the X-ray source with respect to the object mount and the decentering distance of the center of the stop opening with respect to the optical axis of the imaging optics such that X-rays entering the transfer field run parallel to chief imaging rays of imaging light within the imaging light path.
24 . The X-ray inspection method of claim 22 , comprising reading data from a lookup table that stores data with respect to a dependency between actions of the stop drive and actions of the object displacement drive, and
using the data from the lookup table to balance the lateral displacement of the X-ray source with respect to the object mount and the decentering distance of the center of the stop opening of the stop with respect to the optical axis of the imaging optics.
25 . The detection system of claim 1 , wherein the X-ray source is for generating X-rays having energies in the range between 10 keV and 160 keV.
26 . The detection system of claim 1 , wherein the imaging optics has a magnification of 1 or greater.
27 . A detection system including a detection assembly comprising: an imaging optical arrangement to image an object illuminated by X-rays, the imaging optical arrangement comprising
an imaging optics to image a transfer field in a field plane into a detection field in a detection plane via an imaging light path,
a layer of scintillator material arranged at the transfer field, and
a stop being arranged in a pupil plane of the imaging optics,
wherein the imaging optics has an optical axis,
wherein the imaging optical arrangement further comprises a movable optical element for adjusting a property of a chief ray,
the detection assembly further comprising
a detection array arranged at the detection field of the imaging optics, and
an object mount to hold an object to be imaged via the imaging optics,
the detection system further comprising an X-ray source.
28 . The imaging optical arrangement of claim 27 , wherein a center of a stop opening of the stop is arranged at a decentering distance with respect to the optical axis.
29 . The imaging optical arrangement of claim 28 , wherein the decentering distance is at least 10% of a width of the stop opening.
30 . The imaging optical arrangement of claim 27 , wherein the stop is mounted on a drive to translate the stop in the pupil plane.
31 . The imaging optical arrangement of claim 27 , wherein an object side numerical aperture of the imaging optics which is defined by the stop opening is larger than 0.4.
32 . The imaging optical arrangement of claim 27 , wherein the stop is an annular pupil stop.
33 . The detection system of claim 27 , wherein an angle between the X-rays entering the transfer field and the optical axis of the imaging optics is between 0 deg and 80 deg.
34 . The detection system of claim 27 , comprising a lookup table that stores data with respect to a dependency between actions of the optical element drive and actions of the lateral displacement drive,
wherein the control device is configured to use the data stored in the lookup table to control the optical element drive and the lateral displacement drive.
35 . The detection system of claim 27 , further comprising an optical element drive to translate the movable optical element and a control device being in signal connection with the optical element drive and with an object displacement drive to move the object mount along at least one lateral object displacement direction in the object plane.
36 . The detection system of claim 27 , wherein the X-ray source is for generating X-rays having energies in the range between 10 keV and 160 keV.
37 . The detection system of claim 27 , wherein the imaging optics has a magnification of 1 or greater.
38 . The detection system of claim 27 , having a lateral displacement drive for relative lateral displacement of the object mount with respect to the X-ray source.
39 . A detection system including a detection assembly comprising:
an imaging optical arrangement to image an object illuminated by X-rays, the imaging optical arrangement comprising
an imaging optics to image a transfer field in a field plane into a detection field in a detection plane via an imaging light path,
a layer of scintillator material arranged at the transfer field, and
a stop being arranged in a pupil plane of the imaging optics,
wherein the imaging optics has an optical axis,
wherein the imaging optical arrangement further comprises means to axially move the stop for adjusting a chief ray property,
the detection assembly further comprising
a detection array arranged at the detection field of the imaging optics, and
an object mount to hold an object to be imaged via the imaging optics,
the detection system further comprising an X-ray source.
40 . The imaging optical arrangement of claim 39 , comprising an axial pupil stop drive to translate the stop perpendicular to the pupil plane.
41 . The imaging optical arrangement of claim 40 , wherein the axial drive serves as a telecentricity adjustment drive to adjust a telecentricity parameter of the imaging optical arrangement.