Imaging system and corresponding operating method

Abstract

A method includes transmitting a radiation beam (725) to an object (730); rotating the object (730) about a rotation axis (735) perpendicular to an imaging plane of the image sensor (600, 710), where the imaging plane intersects all sensing elements (150) of the image sensor (600, 710); translating the image sensor (600, 710) back and forth relative to the axis of rotation (735) along a translation line (712) perpendicular to the axis of rotation (735); and for i = 1,..., M and j = 1,..., Ni, taking an image (i, j) of the object (730) with an image sensor (600, 710) based on the interaction between the radiation beam (725) and the object (730), where M and Ni, i = 1,..., M and j = 1,..., Ni, are both taken while performing the translation and while performing the rotation.

Description

[Background technology]

[0001] A radiation detector is a device that measures a property of radiation. Examples of such properties may include the spatial distribution of the intensity, phase, polarization of the radiation. The radiation measured by the radiation detector may be radiation that has passed through an object. The radiation measured by the radiation detector may be electromagnetic radiation, such as infrared light, visible light, ultraviolet light, X-rays, or gamma rays. The radiation may be of other types, such as alpha rays and beta rays. An imaging system may include one or more image sensors, each of which may have one or more radiation detectors. [Summary of the invention]

[0002] A method is disclosed herein, comprising: sending a radiation beam to an object; rotating the object around a rotation axis perpendicular to an imaging plane of an image sensor, wherein the imaging plane intersects all sensing elements of the image sensor; translating the image sensor back and forth relative to the rotation axis along a translation line perpendicular to the rotation axis; and for i=1, ..., M and j=1, ..., Ni, based on the interaction between the radiation beam and the object, using the image sensor to capture an image (i, j) of the object, wherein M and Ni, i=1, ..., M, are integers greater than 1, wherein each of the images (i, j), i=1, ..., M and j=1, ..., Ni, is captured while performing the translation and while performing the rotation.

[0003] In one aspect, the image sensor includes a plurality of active areas and a plurality of first gaps between the plurality of active areas, and each of the plurality of first gaps is along a first direction that is not parallel to the translation line.

[0004] In one aspect, the translation has a translation amplitude that is greater than any width of any first gap in the plurality of first gaps measured in a direction parallel to the translation line.

[0005] In one aspect, the image sensor further includes a plurality of second gaps between the plurality of active areas, and each of the plurality of second gaps is along a second direction perpendicular to the first direction.

[0006] In one aspect, the rotation axis intersects an active area of ​​the plurality of active areas or a first gap of the plurality of first gaps, and does not intersect any second gap of the plurality of second gaps.

[0007] In one aspect, the method further comprises stitching the images (i, j), i=1, ..., M and j=1, ..., Ni, thereby obtaining a stitched image of the object.

[0008] In one aspect, the stitching is performed by the image sensor.

[0009] In one aspect, the radiation beam comprises X-rays.

[0010] On the one hand, for each value of i, when the image (i, j), j=1, ..., Ni is captured, each point of the object has a plurality of shadows (i, j), j=1, ..., Ni located on the imaging plane of the image sensor relative to the radiation beam, and the distance between any two shadows of the plurality of shadows (i, j), j=1, ..., Ni of each point located on the imaging plane does not exceed any width of any sensing element of the image sensor.

[0011] On the one hand, the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one image at a time, and the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one value of i at a time.

[0012] In one aspect, the axis of rotation intersects the object.

[0013] A system is disclosed herein, comprising: a radiation source and an image sensor; wherein the radiation source is configured to send a radiation beam to an object; wherein the system is configured to rotate the object around a rotation axis perpendicular to an imaging plane of the image sensor; wherein the imaging plane intersects all sensing elements of the image sensor; wherein the image sensor is configured to translate back and forth relative to the rotation axis along a translation line perpendicular to the rotation axis; wherein, for i=1, ..., M and j=1, ..., Ni, the image sensor is configured to capture an image (i, j) of the object based on an interaction between the radiation beam and the object, wherein M and Ni, i=1, ..., M, are integers greater than 1, and wherein each of the images (i, j), i=1, ..., M and j=1, ..., Ni, is captured while translating the image sensor and while rotating the image sensor.

[0014] In one aspect, the image sensor includes a plurality of active areas and a plurality of first gaps between the plurality of active areas, and each of the plurality of first gaps is along a first direction that is not parallel to the translation line.

[0015] In one aspect, the translation amplitude of translating the image sensor is greater than any width of any first gap of the plurality of first gaps measured in a direction parallel to the translation line.

[0016] In one aspect, the image sensor further includes a plurality of second gaps between the plurality of active areas, and each of the plurality of second gaps is along a second direction perpendicular to the first direction.

[0017] In one aspect, the rotation axis intersects an active area of ​​the plurality of active areas or a first gap of the plurality of first gaps, and does not intersect any second gap of the plurality of second gaps.

[0018] In one aspect, the system is configured to stitch the images (i, j), i=1, ..., M and j=1, ..., Ni, thereby obtaining a stitched image of the object.

[0019] In one aspect, the image sensor is configured to stitch the images (i, j), i=1, ..., M and j=1, ..., Ni.

[0020] In one aspect, the radiation beam comprises X-rays.

[0021] On the one hand, for each value of i, when the image (i, j), j=1, ..., Ni is captured, each point of the object has a plurality of shadows (i, j), j=1, ..., Ni located on the imaging plane of the image sensor relative to the radiation beam, and the distance between any two shadows of the plurality of shadows (i, j), j=1, ..., Ni of each point located on the imaging plane does not exceed any width of any sensing element of the image sensor.

[0022] On the one hand, the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one image at a time, and the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one value of i at a time.

[0023] In one aspect, the axis of rotation intersects the object.

Brief Description of the Drawings

[0024] Figure 1 A radiation detector according to an embodiment is schematically illustrated.

[0025] Figure 2 A simplified cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0026] Figure 3 A detailed cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0027] Figure 4 A detailed cross-sectional view of a radiation detector according to an alternative embodiment is schematically shown.

[0028] Figure 5 A top view of a radiation detector package including a radiation detector and a printed circuit board (PCB) according to an embodiment is schematically shown.

[0029] Figure 6 Schematically shows a system according to an embodiment including a Figure 5 A cross-sectional view of a packaged image sensor.

[0030] Figure 7 A perspective view of an imaging system according to an embodiment is schematically shown.

[0031] Figure 8 A flow chart outlining the operation of an imaging system according to an embodiment is shown. [Specific implementation method]

[0032] Radiation Detectors

[0033] Figure 1 A radiation detector 100 is schematically shown as an example. The radiation detector 100 may include an array of pixels 150 (also referred to as sensing elements 150). The array may be a rectangular array (e.g. Figure 1 as shown), a honeycomb array, a hexagonal array, or any other suitable array. Figure 1 The array of pixels 150 in the example of FIG. 4 has 4 rows and 7 columns; however, in general, the array of pixels 150 may have any number of rows and any number of columns.

[0034] Each pixel 150 can be configured to detect radiation from a radiation source (not shown) incident thereon, and can be configured to measure the characteristics of the radiation (e.g., the energy, wavelength, and frequency of the particles). Radiation may include radiation particles such as photons (X-rays, gamma rays, etc.) and subatomic particles (alpha particles, beta particles, etc.). Each pixel 150 can be configured to count the number of radiation particles incident thereon and whose energy falls into multiple energy bins over a period of time. All pixels 150 can be configured to count the number of radiation particles incident thereon and falling into multiple energy bins over the same period of time. When the incident radiation particles have similar energies, the pixel 150 can be configured only to count the number of radiation particles incident thereon over a period of time without measuring the energy of a single radiation particle.

[0035] Each pixel 150 may have its own analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident radiation particle into a digital signal, or to digitize an analog signal representing the total energy of multiple incident radiation particles into a digital signal. Pixels 150 may be configured to operate in parallel. For example, when one pixel 150 measures an incident radiation particle, another pixel 150 may be waiting for the radiation particle to arrive. Pixels 150 may not necessarily be individually addressable.

[0036] The radiation detector 100 described herein may have applications such as X-ray telescopes, X-ray mammography, industrial X-ray defect detection, X-ray microscopy or microradiography, X-ray casting inspection, X-ray nondestructive testing, X-ray weld inspection, X-ray digital subtraction angiography, etc. It may be appropriate to use the radiation detector 100 instead of a photographic plate, photographic film, a photo-stimulated phosphor plate (PSP plate), an X-ray image intensifier, a scintillator, or other semiconductor X-ray detector.

[0037] Figure 2 Schematically shows a Figure 1 2-2. Specifically, the radiation detector 100 may include a radiation absorbing layer 110 and an electronic circuit layer 120 (which may include one or more ASICs or application specific integrated circuits) for processing and analyzing electrical signals generated in the radiation absorbing layer 110 by incident radiation. The radiation detector 100 may or may not include a scintillator (not shown). The radiation absorbing layer 110 may include a semiconductor material such as silicon, germanium, GaAs, CdTe, CdZnTe, or a combination thereof. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest.

[0038] As an example, Figure 3 Schematically shows Figure 1 Detailed cross-sectional view of the radiation detector 100 along line 2-2. Specifically, the radiation absorbing layer 110 may include one or more diodes (e.g., pin or pn) formed by one or more discrete regions 114 of the first doping region 111, the second doping region 113. The second doping region 113 may be separated from the first doping region 111 by an optional intrinsic region 112. The discrete regions 114 may be separated from each other by the first doping region 111 or the intrinsic region 112. The first doping region 111 and the second doping region 113 may have opposite types of doping (e.g., the first doping region 111 is p-type and the second doping region 113 is n-type, or the first doping region 111 is n-type and the second doping region 113 is p-type). Figure 3In the example of , each discrete region 114 of the second doped region 113 forms a diode with the first doped region 111 and the optional intrinsic region 112. That is, in Figure 3 In the example of FIG. 1 , the radiation absorbing layer 110 has a plurality of diodes (more specifically, 7 diodes corresponding to Figure 1 The array has 7 pixels in a row of 150, for simplicity, Figure 3 Only two pixels 150 are marked in FIG. 1 . The plurality of diodes may have an electrical contact 119A as a common electrode. The first doped region 111 may also have a plurality of discrete portions.

[0039] The electronic circuit layer 120 may include an electronic system 121 suitable for processing or interpreting signals generated by radiation incident on the radiation absorption layer 110. The electronic system 121 may include analog circuits such as filter networks, amplifiers, integrators, and comparators, or digital circuits such as microprocessors and memories. The electronic system 121 may include one or more analog-to-digital converters. The electronic system 121 may include components shared by multiple pixels 150 or components dedicated to a single pixel 150. For example, the electronic system 121 may include an amplifier dedicated to each pixel 150 and a microprocessor shared between all pixels 150. The electronic system 121 may be electrically connected to the pixel 150 through the through hole 131. The space between the through holes may be filled with a filling material 130, which may increase the mechanical stability of the connection between the electronic circuit layer 120 and the radiation absorption layer 110. Other bonding techniques may connect the electronic system 121 to the pixel 150 without using the through hole 131.

[0040] When radiation from a radiation source (not shown) strikes the radiation absorbing layer 110 including a diode, the radiation particles may be absorbed and generate one or more carriers (e.g., electrons, holes) through a variety of mechanisms. The carriers may drift to one of the electrodes of the diodes under an electric field. The electric field may be an external electric field. The electrical contact 119B may include a plurality of discrete portions, each of which is in electrical contact with the discrete region 114. The term "electrical contact" may be used interchangeably with the term "electrode". In one embodiment, the carriers may drift in a plurality of directions, and the carriers generated by a single radiation particle are not substantially shared by two different discrete regions 114 (here "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these carriers flow to a discrete region different from the discrete region to which the remaining carriers flow in the plurality of discrete regions 114). The charge carriers generated by radiation particles incident around the footprint of one of the discrete regions 114 are substantially not shared by another of the discrete regions 114. A pixel 150 associated with a discrete region 114 may be an area around the discrete region 114 in which substantially all (more than 98%, more than 99.5%, more than 99.9%, or more than 99.99%) of the charge carriers generated by radiation particles incident therein flow toward the discrete region 114. That is, less than 2%, less than 1%, less than 0.1%, or less than 0.01% of the charge carriers flow out of the pixel 150.

[0041] Figure 4 Schematically shows a Figure 1 Detailed cross-sectional view of radiation detector 100 along line 2-2. More specifically, radiation absorbing layer 110 may include resistors of semiconductor materials such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof, but not diodes. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest. In one embodiment, Figure 4 The electronic circuit layer 120 is similar in structure and function to Figure 3 The electronic circuit layer 120 is provided.

[0042] When radiation strikes the radiation absorbing layer 110, which includes a resistor but does not include a diode, it can be absorbed and generate one or more carriers through a variety of mechanisms. The radiation particles can generate 10 to 100,000 carriers. The carriers can drift to the electrical contacts 119A and 119B under an electric field. The electric field can be an external electric field. The electrical contact 119B may include multiple discrete portions. In one embodiment, the carriers can drift in multiple directions, and the carriers generated by a single radiation particle are substantially not shared by two different discrete portions of the electrical contact 119B (here "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1% or less than 0.01% of these carriers flow to a discrete portion different from the discrete portion to which the remaining carriers flow). The carriers generated by the radiation particles incident on the occupied space of one of the discrete portions of the electrical contact 119B are substantially not shared by another discrete portion of the discrete portions of the electrical contact 119B. A pixel 150 associated with a discrete portion of electrical contact 119B may be a region around the discrete portion in which substantially all (more than 98%, more than 99.5%, more than 99.9%, or more than 99.99%) of the charge carriers generated by radiation particles incident therein flow toward the discrete portion of electrical contact 119B. That is, less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow out of the pixel associated with the discrete portion of electrical contact 119B.

[0043] Radiation Detector Packaging

[0044] Figure 5 A top view of a radiation detector package 500 including a radiation detector 100 and a printed circuit board (PCB) 510 is schematically shown. The term "printed circuit board" as used herein is not limited to a specific material. For example, the printed circuit board may include a semiconductor. The radiation detector 100 may be mounted to the printed circuit board 510. For clarity, the wiring between the radiation detector 100 and the printed circuit board 510 is not shown. The package 500 may have one or more radiation detectors 100. The printed circuit board 510 may include an input / output (I / O) area 512 that is not covered by the radiation detector 100 (e.g., for accommodating bonding wires 514). The radiation detector 100 may have an active area 190, which is a pixel 150 ( Figure 1 ) is located. The radiation detector 100 may have a peripheral area 195 located near an edge of the radiation detector 100. The peripheral area 195 has no pixels 150, and the radiation detector 100 does not detect radiation particles incident on the peripheral area 195.

[0045] Image Sensor

[0046] Figure 6 Schematically shows a cross-sectional view of an image sensor 600 according to an embodiment. The image sensor 600 may include one or more components mounted to a system printed circuit board 650. Figure 5 Radiation detector package 500. Electrical connection between printed circuit board 510 and system printed circuit board 650 may be made through bonding wires 514. In order to accommodate bonding wires 514 on printed circuit board 510, printed circuit board 510 may have an input / output area 512 that is not covered by radiation detector 100. In order to accommodate bonding wires 514 on system printed circuit board 650, there may be a gap between packages 500. The gap may be about 1 mm or larger. Radiation particles incident on peripheral area 195, input / output area 512, or gap cannot be detected by package 500 on system printed circuit board 650. The dead zone of a radiation detector (e.g., radiation detector 100) is an area of ​​the radiation receiving surface of the radiation detector on which radiation particles incident cannot be detected by the radiation detector. The dead zone of a package (e.g., package 500) is an area of ​​the radiation receiving surface of the package on which radiation particles incident cannot be detected by one or more radiation detectors in the package. In Figure 5 and Figure 6 In the example shown, the dead zone of package 500 includes perimeter area 195 and input / output region 512. The dead zone (e.g., 688) of an image sensor (e.g., image sensor 600) having a group of packages (e.g., multiple packages 500 mounted on the same printed circuit board and arranged in the same layer or different layers) includes a combination of the dead zones of the packages in the group and the gaps between the packages.

[0047] In one embodiment, the autonomous radiation detector 100 ( Figure 1 ) can be considered as an image sensor. In one embodiment, the self-operating package 500 ( Figure 5 ) can be considered as an image sensor.

[0048] The image sensor 600 including the radiation detector 100 may have a dead zone 688 between the active areas 190 of the radiation detector 100. However, the image sensor 600 may capture multiple partial images of an object or scene (not shown) one by one, and then these captured partial images may be stitched together to form a stitched image of the entire object or scene.

[0049] The term "image" as used herein is not limited to the spatial distribution of a property (eg, intensity) of radiation. For example, the term "image" may also include the spatial distribution of the density of a substance or element.

[0050] Imaging System

[0051] Figure 7Schematically, a perspective view of an imaging system 700 according to an embodiment is shown. In one embodiment, the imaging system 700 may include an image sensor 710 and a radiation source 720.

[0052] In one embodiment, the image sensor 710 may be similar to Figure 6 For example, image sensor 710 may include 9 active regions 190 arranged in 3 rows and 3 columns, as shown. In general, image sensor 710 may have any number of active regions 190 that may be arranged in any manner.

[0053] In one embodiment, object 730 may be located between image sensor 710 and radiation source 720, as shown.

[0054] Operation of the imaging system

[0055] In one embodiment, imaging system 700 may operate as follows: Radiation source 720 may send radiation beam 725 toward object 730. In one embodiment, radiation beam 725 may include X-rays.

[0056] In one embodiment, the object 730 may be rotated about a rotation axis 735 that is perpendicular to an imaging plane (not shown) of the image sensor 710, wherein the imaging plane intersects all the sensing elements 150 of the image sensor 710. That is, if all the sensing elements 150 of the image sensor 710 are coplanar, the imaging plane may be a plane that actually intersects all the sensing elements 150 of the image sensor 710. However, if all the sensing elements 150 of the image sensor 710 are not coplanar, then the imaging plane may be a best fit plane (e.g., a least squares plane) of all the sensing elements 150 of the image sensor 710.

[0057] In one embodiment, image sensor 710 may translate back and forth relative to rotation axis 735 along a translation line 712 that is perpendicular to rotation axis 735 .

[0058] In one embodiment, while the object 730 is rotating as described above, and while the image sensor 710 is translating back and forth as described above, the image sensor 710 can capture multiple images of the object 730. Specifically, the image sensor 710 can capture each of the multiple images of the object 730 based on the interaction between the radiation beam 725 and the object 730.

[0059] The interaction between the radiation beam 725 and the object 730 may include situations such as the following: (A) some radiation particles of the radiation beam 725 incident on the object 730 are blocked by the object 730, (B) some radiation particles of the radiation beam 725 incident on the object 730 pass through the object 730 without changing their directions, and (C) some radiation particles of the radiation beam 725 incident on the object 730 collide with atoms of the object 730, thereby changing their directions.

[0060] Flowchart outlining the operation of the imaging system

[0061] Figure 8 shows a summary according to an embodiment Figure 7 Flowchart 800 of the operation of the imaging system 700.

[0062] In step 810, the operation may include sending a radiation beam to an object. For example, in the above embodiment, reference Figure 7 , a radiation source 720 sends a radiation beam 725 toward an object 730 .

[0063] In step 810, the operation may also include rotating the object about a rotation axis perpendicular to an imaging plane of the image sensor, wherein the imaging plane intersects all sensing elements of the image sensor. Figure 7 , the object 730 rotates around a rotation axis 735 that is perpendicular to the imaging plane of the image sensor 710.

[0064] In step 810, the operation may also include translating the image sensor back and forth relative to the rotation axis along a translation line perpendicular to the rotation axis. Figure 7 , the image sensor 710 translates back and forth relative to the rotation axis 735 along a translation line 712 that is perpendicular to the rotation axis 735 .

[0065] In step 820, the operation may include, for i=1, ..., M and j=1, ..., Ni, based on the interaction between the radiation beam and the object, using an image sensor to capture an image (i, j) of the object, wherein M and Ni, i=1, ..., M, are integers greater than 1, wherein each image (i, j), i=1, ..., M and j=1, ..., Ni, is captured while performing the translation and while performing the rotation. For example, in the above embodiment, reference Figure 7 , the image sensor 710 captures each of the multiple images of the object 730 based on the interaction between the radiation beam 725 and the object 730, wherein, as described above, each of the multiple images of the object 730 is captured while the object 730 is rotating and while the image sensor 710 is translated back and forth.

[0066] Other embodiments

[0067] The gap between the active areas of the image sensor

[0068] In one embodiment, reference Figure 7 , the image sensor 710 may further include first gaps 195x between the active areas 190, wherein each first gap 195x may be along a first direction Ox. In one embodiment, the translation line 712 may be selected so that the translation line 712 is not parallel to the first direction Ox of the first gaps 195x (e.g., the translation line 712 may be selected to be perpendicular to the first direction Ox of the first gaps 195x).

[0069] In one embodiment, the image sensor 710 may further include second gaps 195y between the active areas 190, wherein each second gap 195y may be along a second direction Oy. In one embodiment, the second direction Oy of the second gaps 195y may be perpendicular to the first direction Ox of the first gaps 195x.

[0070] In one embodiment, the rotation axis 735 (A) may intersect one of the plurality of active areas 190 of the image sensor 710 or one of the plurality of first gaps 195x, and (B) may not intersect any of the plurality of second gaps 195y. Figure 7 As shown, rotation axis 735 intersects active area 190 of image sensor 710 .

[0071] Translation Amplitude

[0072] In one embodiment, reference Figure 7 , the image sensor 710 can be translated back and forth between a first end position and a second end position (not shown). The distance between the first end position and the second end position can be referred to as the translation amplitude. In one embodiment, the translation amplitude of the back and forth translation of the image sensor 710 can be greater than any width of any first gap 195x measured in a direction parallel to the translation line 712.

[0073] Image stitching

[0074] In one embodiment, reference Figure 7 and Figure 8 In step 820 , after executing step 820 , the images (i, j), i=1, ..., M and j=1, ..., Ni may be spliced ​​to obtain a spliced ​​image of the object 730 .

[0075] In one embodiment, the image sensor 710 may perform stitching of images (i, j), i=1, ..., M and j=1, ..., Ni as described above.

[0076] Image capture

[0077] In one embodiment, reference Figures 7 and 8 , a plurality of images (i, j), i=1, ..., M and j=1, ..., Ni may be captured one image at a time by the image sensor 710. In other words, all images of the object 730 captured by the image sensor 710 are captured one image at a time.

[0078] In one embodiment, multiple images (i, j), i=1, ..., M and j=1, ..., Ni may be captured one value of i at a time. For example, image (1, j), j=1, ..., N1 (corresponding to i=1) may be captured first. Then, image (2, j), j=1, ..., N2 (corresponding to i=2) may be captured. Then, image (3, j), j=1, ..., N3 (corresponding to i=3) may be captured, and so on. Please note that the phrase "one value of i at a time" does not include the following scenario: capturing image (1, 1), then capturing image (2, 1), and then capturing image (1, 2).

[0079] In one embodiment, for each value of i, during the time period of capturing images (i, j), j=1, ..., Ni, the rotation of the object 730 around the rotation axis 735 can be ignored. Specifically, in one embodiment, for each value of i, when images (i, j), j=1, ..., Ni are captured, each point of the object 730 has a plurality of shadows (i, j), j=1, ..., Ni located on the imaging plane of the image sensor 710 relative to the radiation beam 725; and the distance between any two of the plurality of shadows (i, j), j=1, ..., Ni of each point located on the imaging plane may not exceed any width of any sensing element 150 of the image sensor 710.

[0080] In other words, for each value of i, the maximum distance between two shadows of each point in the multiple shadows (i, j), j=1, ..., Ni located on the imaging plane does not exceed the minimum size of any sensing element 150 of the image sensor 710.

[0081] Rotation axis and object

[0082] In one embodiment, axis of rotation 735 may intersect object 730 , as shown.

[0083] Example of Operation of Imaging System 700

[0084] In an example of operation of the imaging system 700, reference is made to Figure 7 , the image sensor 710 may include 9 active areas 190 arranged in 3 rows and 3 columns, as shown. In one embodiment, the image sensor 710 may also include 2 first gaps 195x and 2 second gaps 195y between the 9 active areas 190, as shown. In addition, the first direction Ox of the first gap 195x may be perpendicular to the second direction Oy of the second gap 195y.

[0085] In one embodiment, the object 730 can be rotated continuously (e.g., counterclockwise) about a rotation axis 735 that is perpendicular to the imaging plane of the image sensor 710. In addition, the rotation axis 735 can intersect the active area 190 of the image sensor 710, as shown. In one embodiment, the rotation axis 735 can intersect the object 730.

[0086] In one embodiment, while the object 730 rotates about the rotation axis 735 as described above, the image sensor 710 can translate back and forth between the first end position and the second end position along a translation line 712 that can be perpendicular to the rotation axis 735. In addition, the translation line 712 can be perpendicular to the first direction Ox of the first gap 195x.

[0087] In one embodiment, the image sensor 710 can be translated back and forth between the first end position and the second end position without stopping (i.e., the image sensor 710 stops only at the first end position and the second end position). In one embodiment, the translation amplitude can be greater than any width of any first gap 195x measured in a direction parallel to the translation line 712.

[0088] First image and second image of the object

[0089] In one embodiment, while the image sensor 710 is at the first end position and the object 730 is at the first angular position, the image sensor 710 may capture a first image of the object 730. Then, when the image sensor 710 reaches the second end position and the object 730 reaches the second angular position, the image sensor 710 may capture a second image of the object 730.

[0090] In one embodiment, when taking the first image and the second image, each point of the object 730 has two shadows relative to the radiation beam 725 located on the imaging plane of the image sensor 710, and the distance between the two shadows of each point located on the imaging plane may not exceed any width of any sensing element 150 of the image sensor 710.

[0091] exist Figure 8In the case of step 820, the first image may be image (1, 1), and the second image may be image (1, 2). Here, i=1, N1=2.

[0092] The third and fourth images of the object

[0093] In one embodiment, after capturing the second image, object 730 may be rotated approximately 20 degrees counterclockwise to a third angular position while image sensor 710 is translated back and forth a plurality of times.

[0094] Then, in one embodiment, while image sensor 710 is in the first end position and object 730 is approximately in the third angular position, image sensor 710 may capture a third image of object 730. Then, when image sensor 710 reaches the second end position and object 730 reaches the fourth angular position, image sensor 710 may capture a fourth image of object 730.

[0095] In one embodiment, when taking the third image and the fourth image, each point of the object 730 has two shadows relative to the radiation beam 725 located on the imaging plane of the image sensor 710; and the distance between the two shadows of each point located on the imaging plane may not exceed any width of any sensing element 150 of the image sensor 710.

[0096] exist Figure 8 In the case of step 820, the third image may be image (2, 1), and the fourth image may be image (2, 2). Here, i=2, N2=2.

[0097] Additional images of objects

[0098] Then, in one embodiment, the process may continue in a similar manner until i=5, wherein all N1=N2=N3=N4=N5=2. Then, in one embodiment, the obtained 10 images of the object 730 (including the first image, the second image, the third image, and the fourth image) may be stitched together to form a stitched image of the object 730.

[0099] Although various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

Claims

1. A method comprising: sending a radiation beam toward an object; Rotating the object about a rotation axis perpendicular to an imaging plane of an image sensor, wherein the imaging plane intersects all sensing elements of the image sensor; translating the image sensor back and forth relative to the rotation axis along a translation line perpendicular to the rotation axis; and for i=1, ..., M and j=1, ..., Ni, based on the interaction between the radiation beam and the object, using the image sensor to capture an image (i, j) of the object, wherein M and Ni, i=1, ..., M, are integers greater than 1, Each of the images (i, j), i=1, ..., M and j=1, ..., Ni, is captured while performing the translation and while performing the rotation.

2. The method according to claim 1, in, The image sensor includes a plurality of active areas and a plurality of first gaps between the plurality of active areas, and Each of the plurality of first gaps is along a first direction that is not parallel to the translation line.

3. The method according to claim 2, wherein: The translation has a translation amplitude that is greater than any width of any first gap of the plurality of first gaps measured in a direction parallel to the translation line.

4. The method according to claim 2, in, The image sensor further includes a plurality of second gaps between the plurality of active areas, and Each of the plurality of second gaps is along a second direction perpendicular to the first direction.

5. The method according to claim 4, wherein: The rotation axis intersects one of the plurality of effective areas or one of the plurality of first gaps, and does not intersect any of the plurality of second gaps. 6 . The method according to claim 1 , further comprising stitching the images (i, j), i=1, ..., M and j=1, ..., Ni, to obtain a stitched image of the object.

7. The method according to claim 6, wherein: The stitching is performed by the image sensor.

8. The method according to claim 1, wherein: The radiation beam includes X-rays.

9. The method according to claim 1, in, For each value of i, when the image (i, j), j=1, ..., Ni is captured, each point of the object has a plurality of shadows (i, j), j=1, ..., Ni, respectively, located on the imaging plane of the image sensor relative to the radiation beam, and Among them, the distance between any two shadows of the multiple shadows (i, j), j=1, ..., Ni of each point located on the imaging plane does not exceed any width of any sensing element of the image sensor.

10. The method according to claim 9, in, The images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one image at a time, and Here, the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one value of i at a time.

11. The method according to claim 1, wherein: The rotation axis intersects the object.

12. A system comprising: Radiation source and image sensor; wherein the radiation source is configured to send a radiation beam to the object; wherein the system is configured to rotate the object about a rotation axis perpendicular to an imaging plane of the image sensor, wherein the imaging plane intersects all sensing elements of the image sensor; wherein the image sensor is configured to translate back and forth relative to the rotation axis along a translation line perpendicular to the rotation axis; wherein, for i=1, ..., M and j=1, ..., Ni, the image sensor is configured to capture an image (i, j) of the object based on the interaction between the radiation beam and the object, wherein M and Ni, i=1, ..., M, are integers greater than 1, and Each of the images (i, j), i=1, ..., M and j=1, ..., Ni, is captured while translating the image sensor and while rotating the image sensor.

13. The system according to claim 12, in, The image sensor includes a plurality of active areas and a plurality of first gaps between the plurality of active areas, and Each of the plurality of first gaps is along a first direction that is not parallel to the translation line.

14. The system according to claim 13, wherein: The translation amplitude of translating the image sensor is greater than any width of any first gap of the plurality of first gaps measured in a direction parallel to the translation line.

15. The system according to claim 13, in, The image sensor further includes a plurality of second gaps between the plurality of active areas, and Each of the plurality of second gaps is along a second direction perpendicular to the first direction.

16. The system of claim 15, wherein: The rotation axis intersects one of the plurality of effective areas or one of the plurality of first gaps, and does not intersect any of the plurality of second gaps.

17. The system of claim 12, wherein: The system is configured to stitch the images (i, j), i=1, ..., M and j=1, ..., Ni, thereby obtaining a stitched image of the object.

18. The system of claim 17, wherein: The image sensor is configured to stitch the images (i, j), i=1, ..., M and j=1, ..., Ni.

19. The system of claim 12, wherein: The radiation beam includes X-rays.

20. The system according to claim 12, in, For each value of i, when the image (i, j), j=1, ..., Ni is captured, each point of the object has a plurality of shadows (i, j), j=1, ..., Ni, respectively, located on the imaging plane of the image sensor relative to the radiation beam, and Among them, the distance between any two shadows of the multiple shadows (i, j), j=1, ..., Ni of each point located on the imaging plane does not exceed any width of any sensing element of the image sensor.

21. The system according to claim 20, in, The images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one image at a time, and Here, the images (i, j), i=1, ..., M and j=1, ..., Ni, are captured one value of i at a time.

22. The system of claim 12, wherein: The rotation axis intersects the object.

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