JP2019191116A - Radiation detection device and inspection device - Google Patents

Abstract

To achieve improvement in quality of a radiation detection device with a comparatively simple configuration.SOLUTION: A radiation detection device comprises: a sensor substrate that has a plurality of sensor parts for detecting radiation arrayed in a prescribed direction; a phosphor that is arranged in a location separated from the sensor substrate in a direction going across either direction of an array direction of the plurality of sensor parts and an incidence direction of radiation, and is configured to be capable of converting the radiation to light; a first radiation shield member that is arranged lateral to an array direction of the sensor substrate; and a second radiation shield member that is arranged between the sensor substrate and the phosphor, and is configured to allow light of the phosphor to pass to the plurality of sensor parts. When viewing in the going-across direction, the second radiation shield member is arranged so as to overlap with the first radiation shield member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation detection apparatus and an inspection apparatus.

  In Patent Document 1, a radiation shielding member is disposed in order to prevent a user such as a doctor from being exposed to radiation incident on the radiation detection apparatus by being scattered by each member of the apparatus and leaking from the apparatus. Is described.

JP 2006-322745 A JP 2008-082664 A

  Patent Document 2 describes a radiation detection apparatus including a phosphor that converts radiation into light and a line sensor in which a plurality of sensor units that detect the light are arranged. Many members generally deteriorate due to exposure to radiation, but this is also the case with the sensor unit. For example, the sensor characteristics may vary due to radiation caused by the scattering. In the case of the configuration of Patent Document 2, it is considered that the radiation dose due to the scattering is relatively large (for example, compared with the central region) in the end region of the line sensor, and therefore the characteristics of the line sensor become non-uniform. There was a possibility. This can cause a deterioration in the quality of the radiation detection apparatus, so there is room for improvement in structure.

  An object of this invention is to implement | achieve the improvement of the quality of a radiation detection apparatus with a comparatively simple structure.

  One aspect of the present invention relates to a radiation detection apparatus, and the radiation detection apparatus includes: a sensor substrate in which a plurality of sensor units for detecting radiation are arranged in a predetermined direction; and a plurality of sensor units from the sensor substrate. A phosphor arranged at a position spaced in a direction intersecting both the arrangement direction and the incident direction of the radiation and configured to convert radiation into light, and a first arranged on the side of the arrangement direction of the sensor substrate. 1 radiation shielding member, and a second radiation shielding member disposed between the sensor substrate and the phosphor, and configured to allow the light of the phosphor to pass through the plurality of sensor units, The second radiation shielding member is positioned so as to overlap with the first radiation shielding member when viewed in the intersecting direction.

  According to the present invention, the quality of the radiation detection apparatus can be improved.

It is a figure for demonstrating the example of a structure of a radiation detection apparatus, and the example of its internal structure. It is a figure for demonstrating the example of the internal structure of a radiation detection apparatus. It is a figure for demonstrating the example of a structure of a radiation detection apparatus, and the example of its internal structure. It is a figure for demonstrating the example of a structure of a radiation detection apparatus, and the example of its internal structure. It is a figure for demonstrating the structural example of an inspection apparatus.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Each figure is only a schematic diagram described for the purpose of explaining the structure or configuration, and the dimensions of each member shown do not necessarily reflect actual ones. Moreover, in each figure, the same reference number is attached | subjected to the same member or the same element, and description is abbreviate | omitted about the overlapping content hereafter.

[First Embodiment]
FIG. 1A is a perspective view showing the configuration of the radiation detection apparatus 1 according to the first embodiment. In the present embodiment, the radiation detection apparatus 1 may be elongated and may be expressed as a radiation line sensor or the like.

  The same applies to other figures described later, but in the figure, the X direction, the Y direction, and the Z direction that intersect or substantially orthogonal to each other are shown for easy understanding of the structure. The X direction corresponds to the short direction of the long radiation detection apparatus 1, the Y direction corresponds to the longitudinal direction of the apparatus 1, and the Z direction corresponds to the height direction of the apparatus 1. In this specification, for simplification of description, an expression indicating a relative positional relationship between two or more members or elements in the radiation detection apparatus 1 is used. For example, in this specification, the positional relationship shifted in the + X / −X direction may be expressed as “X direction side” or the like, but may be expressed as a lateral direction side or the like. In this specification, the positional relationship shifted in the + Y / −Y direction may be expressed as “Y direction side” or the like, but may be expressed as “longitudinal direction side” or the like. In this specification, the positional relationship shifted in the + Z direction is expressed as “up”, “upward”, and the positional relationship shifted in the −Z direction is expressed as “down”, “downward”, etc. There is.

  FIG. 1B shows a cross-sectional structure of the radiation detection apparatus 1 in which the cut surface is an XZ plane (vertical surface). FIG. 1C shows a side view of FIG. 1B viewed in the + Y direction. FIG. 2A shows a cross-sectional structure of the radiation detection apparatus 1 having a cut surface as an XY plane (horizontal plane). FIG. 2B shows a top view of FIG. 2A viewed in the −Z direction. The radiation detection apparatus 1 includes a housing 10, a sensor substrate 11, a phosphor (scintillator) 12, and radiation shielding members 131 to 133.

  The housing 10 is composed of one or more members and directly / indirectly supports members or elements constituting the radiation detection apparatus 1 and is also expressed as a support or the like. The housing 10 may be expressed as a support frame, or simply a frame, depending on its shape. In the present embodiment, the housing 10 includes a first support member 101 that supports the sensor substrate 11 and a second support member 102 that supports the phosphor 12. An insulating material such as a resin may be used for the housing 10, here, the support members 101 and 102, but a material having a relatively high radiation resistance is more preferably used. For example, a material containing particles capable of shielding (or absorbing) radiation, such as tungsten (W) and lead (Pb), for example, a tungsten-containing resin can be suitably used.

  In this embodiment, the support members 101 and 102 are fixed to each other by a fastening member, an adhesive, or the like. However, as another embodiment, the support members 101 and 102 may be integrally formed.

  Although details will be described later, the support member 101 includes a pair of end portions 101Ea and 101Eb that face each other in the Y direction, and as shown in FIGS. 2A and 2B, the pair of end portions 101Ea. And 101Eb, the sensor substrate 11 is supported. Although the same applies to the end portion 101Eb, in this embodiment, as shown in FIG. 2B, the thickness (thickness in the Y direction) T1 of the end portion 101Ea is changed from the end portion 101Ea to the sensor substrate 11. It is assumed that the distance is larger than the distance L1. The support member 101 further includes a side wall portion (a plate portion forming a YZ plane) and a bottom surface portion (a plate portion forming an XY plane) connecting the pair of end portions 101Ea and 101Eb. The sensor substrate 11 can be accommodated in a space formed by each part 101 and the radiation shielding member 132.

  The support member 102 is disposed on the side of the support member 101 in the X direction and supports the phosphor 12. In the present embodiment, the upper surface of the support member 102 is inclined so as to face the support member 101, and thus the phosphor 12 is fixed in an inclined posture. The inclination means a state that is not horizontal and not vertical, and the inclination angle (angle formed with the horizontal plane) of the upper surface of the support member 102 is, for example, in the range of 10 to 80 degrees, and preferably in the range of 20 to 70 degrees. ,And it is sufficient.

  In the present embodiment, the sensor substrate 11 is fixed in a vertical posture (a posture in which the surface direction is parallel to the YZ plane). The sensor board 11 is a printed board made of, for example, epoxy glass, and a line sensor 111 is formed on the sensor board 11. The line sensor 111 extends in the Y direction, and a plurality of sensor units are arranged in the Y direction so as to form one or more rows.

  Examples of the line sensor 111 include a CCD / CMOS image sensor, and the plurality of sensor units include, for example, a photoelectric conversion element such as a photodiode, and a circuit unit for driving the photoelectric conversion element. The concept of this circuit part includes one or more transistors that form a pixel together with a photoelectric conversion element and read signals from the photoelectric conversion element, as well as a circuit part outside the pixel for controlling them, such as a shift Registers, latch circuits, decoders, and the like are also included.

The phosphor 12 is configured to convert radiation into light. As a material of the phosphor 12, for example, a material in which gadolinium oxysulfide (Gd ₂ O ₂ S: Tb (GOS)) particles are contained in a binder such as a resin can be used. As a material of the phosphor 12, a material containing other known phosphor particles such as lutetium oxysulfide (Lu ₂ O ₂ S: Tb (LOS)) particles in addition to GOS particles may be used. With such a configuration, the phosphor 12 generates light having an intensity (light quantity) corresponding to the dose in response to radiation incident on the radiation detection apparatus 1. This light is also called scintillation light.

  The radiation shielding members 131 to 133 are made of a material having a lower radiation transmittance than the housing 10, here, the support members 101 and 102. For example, the radiation shielding members 101 to 103 are made of a material capable of shielding radiation, such as tungsten or lead. Alternatively, the radiation shielding members 101 to 103 may be made of a material (for example, a tungsten-containing resin) containing particles (for example, particles of tungsten, lead, etc.) that can shield radiation, and in that case, the content of the particles May be configured to be larger than the housing 10.

  The first radiation shielding member 131 is disposed between each of the pair of end portions 101Ea and 101Eb and the sensor substrate 11. In the present embodiment, the radiation shielding member 131 is a plate-like member installed in a posture parallel to the XZ direction. Therefore, the two radiation shielding members 131 are installed facing each other on both sides in the Y direction of the sensor substrate 11. In the present embodiment, the radiation shielding member 131 is fixed to the end portion 101Ea (or 101Eb) with an adhesive. Although the details will be described later, the radiation shielding member 131 is disposed so as to overlap the phosphor 12 when viewed in the X direction (from the viewpoint in the X direction).

  The second radiation shielding member 132 is disposed between the sensor substrate 11 and the phosphor 12 in the X direction and between the pair of end portions 101Ea and 101Eb in the Y direction. In the present embodiment, the radiation shielding member 132 is fixed to the end portions 101Ea and 101Eb and the bottom surface portion of the support member 101 with an adhesive. The radiation shielding member 132 is configured to be able to pass scintillation light from the phosphor 12, and in the present embodiment, has an opening (slit hole) 132OP extending in the Y direction and allowing light to pass therethrough.

  Although details will be described later, the radiation shielding member 132 is positioned so as to overlap the radiation shielding member 131 when viewed in the X direction. Further, the radiation shielding member 131 and the radiation shielding member 132 may be in direct contact with each other or indirectly (via an adhesive or the like).

  As shown in FIG. 1A and the like, the third radiation shielding member 133 is arranged as a top plate on the support member 101, and together with the support member 101 and the radiation shielding member 132, in a space formed by them. The sensor substrate 11 and the line sensor 111 are accommodated. The radiation shielding member 133 is disposed so as to overlap both the radiation shielding members 131 and 132 when viewed in the Z direction (from the viewpoint in the Z direction).

  With the above-described structure, the radiation detection apparatus 1 can detect radiation (typically X-rays are used, but other electromagnetic waves such as alpha rays and beta rays may be used). In this embodiment, radiation is assumed to be incident in the −Z direction, and is converted into light (scintillation light) by the phosphor 12. The scintillation light is emitted from the phosphor 12 in the + X direction, passes through the opening 132OP, travels toward the sensor substrate 11, and is detected by the line sensor 111. The radiation detection apparatus 1 generates radiation image data based on the detection result by the line sensor 111, and outputs this to an external apparatus (for example, a display, a general-purpose computer).

  As described above, the phosphor 12 is fixed in an inclined posture, so that scintillation light can be emitted in the + X direction, which is a direction different from the −Z direction, which is the incident direction of radiation, that is, toward the sensor substrate 11. ing. In order to achieve this appropriately, the inclination angle of the upper surface of the support member 102 is such that the relative position between the phosphor 12 and the opening 132OP, the directivity of the scintillation light of the phosphor 12, the size of the opening 132OP (size in the Z direction), etc. A suitable value may be selected based on the above. In addition, in order to more appropriately guide the scintillation light to the sensor substrate 11, a light guide unit such as a rod lens array may be disposed in the opening 132OP.

  By the way, the radiation irradiated to the radiation inspection apparatus 1 is scattered in various directions in each member of the radiation inspection apparatus 1. Such radiation is also called scattered radiation, scattered radiation, and the like. FIG. 2B further shows an enlarged schematic view of the one end portion 101Eb of the support member 101 and its peripheral region. As indicated by the one-dot chain line arrow in this enlarged schematic diagram, a part of the radiation incident in the −Z direction is scattered by the phosphor 12 and the support member 102 and can be scattered, for example, toward the end portion 101Eb (primary order). scattering). Further, as shown by the two-dot chain line arrow in this enlarged schematic diagram, part of the scattered radiation from the phosphor 12 and the support member 102 can be further scattered by the end portion 101Eb (secondary scattering). Although detailed description is omitted here, actually, scattered rays from outside the radiation inspection apparatus 1 (for example, scattered rays from other devices (not shown) arranged around the radiation inspection apparatus 1) are also included. Because it can exist, secondary scattering due to this can also occur. The above-described primary scattering and secondary scattering can occur in the end portion 101Ea as well.

  Since the radiation is irradiated toward the phosphor 12, the primary scattering is likely to occur in the phosphor 12 and its peripheral portion. Since part of the scattered radiation due to the primary scattering travels toward the line sensor 111 side, this may cause a characteristic variation in the line sensor 111. This characteristic variation includes, for example, variation in transistor characteristics (threshold voltage), sensor sensitivity (photoelectric conversion efficiency), and the like, variation in output value (signal value) resulting therefrom, and the like. On the other hand, in the present embodiment, the radiation shielding member 132 is positioned so as to overlap the radiation shielding member 131 when viewed in the X direction. Therefore, the scattered radiation caused by the primary scattering is caused by the radiation shielding members 131 and 132. It does not leak into the line sensor 111 from between. Therefore, according to the present embodiment, the characteristic uniformity of the line sensor 111 can be maintained, and the quality of the radiation detection apparatus can be improved with a relatively simple configuration.

  Further, the scattered radiation caused by the secondary scattering may enter the sensor substrate 11 and change the characteristics of the line sensor 111. When the radiation shielding member 131 is not disposed, the dose of the scattered radiation increases in the end region of the line sensor 111, and the characteristic uniformity of the line sensor 111 may be lost. On the other hand, according to the present embodiment, since the radiation shielding member 131 is disposed between each of the end portions 101Ea and 101Eb and the sensor substrate 11, the scattered radiation caused by the secondary scattering is not detected by the sensor substrate. 11 does not enter. Therefore, according to the present embodiment, the characteristic uniformity of the line sensor 111 can be maintained, and the quality of the radiation detection apparatus can be improved with a relatively simple configuration.

  Depending on the arrangement of other devices in the vicinity of the radiation inspection apparatus 1, between the end (one end) 101Ea and the sensor substrate 11 and between the end (other end) 101Eb and the sensor substrate 11 The radiation shielding member 131 on one side can be omitted. That is, the radiation shielding member 131 may be disposed between at least one of the end portion 101Ea and the sensor substrate 11 and between the end portion 101Eb and the sensor substrate 11.

  Further, since the phosphor 12 is extended longer than the opening 132OP in order to improve the uniformity of the amount of scintillation light, the scattered radiation from the phosphor 12 can be relatively large. Therefore, the radiation shielding member 131 is preferably arranged so as to overlap the phosphor 12 when viewed in the X direction.

  In addition, the dose of scattered radiation can increase as the member that causes radiation scattering is thicker and / or the distance from the member is smaller. In the present embodiment, each of the end portions 101Ea and 101Eb has a thickness T1 larger than the distance L1 to the sensor substrate 11. Therefore, according to the present embodiment, the influence that the scattered radiation may have on the line sensor 111 is appropriately suppressed or reduced by the radiation shielding member 131.

  In the present embodiment, the radiation shielding member 132 is positioned so as to overlap the radiation shielding member 131 when viewed in the X direction. Therefore, the scattered radiation resulting from the primary scattering does not leak into the sensor substrate 11 from between the radiation shielding members 131 and 132. Therefore, according to the present embodiment, the characteristic uniformity of the line sensor 111 can be maintained, and the quality of the radiation detection apparatus can be improved with a relatively simple configuration.

[Second Embodiment]
The radiation shielding member 132 shown in the first embodiment may be configured to shield scattered radiation from the phosphor 12 and to allow scintillation light to pass therethrough. For example, the opening 132OP is provided with radiation shielding glass. May be.

  FIG. 3A is a perspective view showing a configuration of the radiation detection apparatus 1 according to the present embodiment. FIG. 3B shows a side view of the cross-sectional structure of the device 1 with the cut surface taken as an XZ plane as viewed in the + Y direction. FIG. 3C shows a top view of the cross-sectional structure of the device 1 with the cut surface taken as an XY plane, as viewed in the −Z direction.

  The radiation detection apparatus 1 further includes a translucent plate 14 arranged to cover the opening 132OP of the radiation shielding member 132. The plate member 14 is configured to be able to pass scintillation light and shield radiation, and as the plate member 14, for example, radiation shielding glass such as lead glass is used.

  According to the present embodiment, by arranging the plate member 14 configured to be able to pass scintillation light and shield radiation, the scattered rays from the phosphor 12 to the sensor substrate 11 can be appropriately shielded. . Therefore, according to the present embodiment, in addition to the same effects as those of the first embodiment, the scattered radiation from the phosphor 12 to the sensor substrate 11 can be more appropriately shielded, which is further advantageous in improving the quality of the radiation detection apparatus. .

  The plate member 14 may be arranged in the opening 132OP, but may be arranged by shifting from the opening 132OP in the + X direction or the −X direction. When a light guide unit such as a rod lens array is disposed in the opening 132OP, the plate member 14 may be disposed so as to be shifted in the −X direction from the opening 132OP.

[Third Embodiment]
As described with reference to FIG. 2B in the first embodiment, the scattered radiation from the phosphor 12 may be further scattered at the end portions 101Ea and 101Eb, resulting in secondary scattering. Therefore, the radiation shielding members 131 and 132 shown in the first embodiment may be installed so as to engage or fit with each other. That is, it is preferable that one of the radiation shielding members 131 and 132 is not simply brought into contact with the other, but one of the radiation shielding members 131 and 132 is engaged or fitted with the other, and they overlap each other when viewed in the Y direction.

  FIG. 4A is a perspective view showing a configuration of the radiation detection apparatus 1 according to the present embodiment. FIG. 4B shows a cross-sectional structure of the apparatus 1 in which the cut surface is an XY plane. FIG. 4C illustrates a top view of FIG. 4B viewed in the −Z direction.

  In the present embodiment, as shown in FIGS. 4B and 4C, a notch 132 </ b> C is provided in a portion of the radiation shielding member 132 adjacent to the radiation shielding member 131, and the end of the radiation shielding member 131 is provided. The portion engages with this notch 132C. According to the present embodiment, the radiation shielding member 132 is disposed so as to overlap the radiation shielding member 131 not only when viewed in the X direction but also when viewed in the Y direction. Therefore, the radiation shielding members 131 and 132 are close to each other on the two surfaces, that is, face each other in both the X direction and the Y direction.

  According to the present embodiment, it is possible to appropriately prevent the scattered radiation from the end portions 101Ea and 101Eb accompanying secondary scattering from leaking into the sensor substrate 11 from between the radiation shielding members 131 and 132. Therefore, according to this embodiment, it is further advantageous for quality improvement of the radiation detection apparatus 1.

  In the present embodiment, the cutout 132C has a substantially rectangular shape, but as another embodiment, the cutout 132C may have a rounded shape. As yet another embodiment, one or more concave portions such as a U shape, a V shape, and a W shape may be provided in the radiation shielding member 132 in place of the notch 132C. In that case, the radiation shielding members 131 and 132 are fitted in close proximity to each other on two or more surfaces, and it becomes possible to more appropriately prevent the scattered rays from leaking into the sensor substrate 11. As still another embodiment, the radiation shielding member 131 may be provided with a notch or a recess in place of the notch 132C (or the recess).

[Application example]
The radiation detection apparatus 1 of each embodiment described above is applied to an inspection apparatus (inspection system) for performing a predetermined inspection. Examples of this inspection apparatus include various radiation inspection apparatuses such as a product inspection apparatus in a production line such as a factory, a baggage inspection apparatus used in boarding procedures at an airport, and a medical radiation imaging apparatus.

  FIG. 5 shows an example of a system configuration of the inspection apparatus SY to which the radiation detection apparatus 1 is applied. The inspection apparatus SY includes a radiation detection apparatus 1, a radiation source 2 that generates radiation, and a system controller 3 that can communicate with them. The radiation source 2 generates radiation based on a control signal from the system controller 3. The radiation detection apparatus 1 detects radiation that has been irradiated from the radiation source 2 and passed through the inspection object OB. The system controller 3 receives radiation image data from the radiation detection apparatus 1 and displays a radiation image based on the radiation image data on a predetermined display. The radiation image data may be generated outside the radiation detection apparatus 1, and as another embodiment, for example, may be generated by the system controller 3 based on a signal group received from the radiation detection apparatus 1. With such a configuration, it is possible to realize inspection for the inspection object OB.

  In the above-described embodiments, some preferred aspects have been illustrated, but the present invention is not limited to these examples, and some of the embodiments may be modified or combined without departing from the spirit of the present invention. May be. In addition, it is needless to say that each term described in this specification is merely used for the purpose of describing the present invention, and the present invention is not limited to the strict meaning of the term. The equivalent can also be included.

  10: housing, 101: (first) support member, 102: (second) support member, 11: sensor substrate, 12: phosphor, 131: (first) radiation shielding member), 132: ( Second) radiation shielding member.

Claims (11)

A sensor substrate on which a plurality of sensor units for detecting radiation are arranged in a predetermined direction;
A phosphor arranged at a position spaced from the sensor substrate in a direction intersecting both the arrangement direction of the plurality of sensor units and the incident direction of the radiation, and configured to convert radiation into light; and
A first radiation shielding member disposed on the side of the sensor substrate in the arrangement direction;
A second radiation shielding member disposed between the sensor substrate and the phosphor and configured to allow the light of the phosphor to pass through the plurality of sensor units;
The radiation detection apparatus, wherein the second radiation shielding member is positioned so as to overlap the first radiation shielding member when viewed in the intersecting direction. The radiation detection apparatus according to claim 1, wherein the first radiation shielding member is disposed on each side of the sensor substrate in the arrangement direction. A housing that houses the sensor substrate, the phosphor, the first radiation shielding member, and the second radiation shielding member;
The radiation detection apparatus according to claim 1, wherein the first radiation shielding member and the second radiation shielding member are made of a material having a radiation transmittance lower than that of the housing. . The radiation detection according to any one of claims 1 to 3, wherein the second radiation shielding member further overlaps the first radiation shielding member when viewed in the arrangement direction. apparatus. The said 1st radiation shielding member is engaging with the said 2nd radiation shielding member in the edge part by the side of the said 2nd radiation shielding member. The any one of Claims 1-4 characterized by the above-mentioned. The radiation detection apparatus according to item. The radiation detecting apparatus according to claim 5, wherein a concave portion is provided in a portion of the second radiation shielding member adjacent to the first radiation shielding member. The radiation detection apparatus according to any one of claims 1 to 6, wherein the first radiation shielding member and the second radiation shielding member are adjacent to each other on two or more surfaces. The radiation detection apparatus according to any one of claims 1 to 7, wherein the first radiation shielding member is in contact with the second radiation shielding member. The radiation detection apparatus according to any one of claims 1 to 8, wherein the second radiation shielding member has an opening for allowing the light of the phosphor to pass through the plurality of sensor units. . The radiation detection apparatus according to claim 9, further comprising a translucent plate that is disposed so as to cover the opening of the second radiation shielding member and shields the radiation. The radiation detection apparatus according to any one of claims 1 to 10,
An inspection apparatus comprising: a radiation source that generates radiation.

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