JP2012047627A - Radiation detection panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a constitution member from deforming, for example, warping and so on owing to temperature change, and to make it easy to determine whether a state suited to detection of radiation is entered.SOLUTION: A storage body 16 and a lid 18 constituting a housing 14 of an electronic cassette 10 are displaceable along a thickness of the housing 14, a scintillator 34 absorbing irradiating radiation and emitting light is attached on a side of the storage body 16, and a radiation detection part (TFT substrate) 42 which detects the light emitted from the scintillator 34 as an image is attached on a side of the lid 18. The housing 14 is switched to a maximum thickness state ((A) reference) or a minimum thickness state ((B) reference) with air pressure supplied into the housing from an air pressure generation device 28 connected to a connection part 22. When the electronic cassette 10 is not in use, the maximum thickness state in which the scintillator 34 and radiation detection part 42 are apart from each other is entered and when a radiation image is photographed, the minimum thickness state in which the scintillator 34 and radiation detector 42 come into contact with each other over the entire surfaces is entered.

Description

  The present invention relates to a radiation detection panel, and more particularly, to a radiation detection panel including a light emission unit that absorbs radiation transmitted through a subject and emits light and a detection unit that detects light emitted from the light emission unit.

In recent years, radiation sensitive layers have been arranged on TFT (Thin Film Transistor) active matrix substrates to detect irradiated X-rays, γ-rays, α-rays, and other radiation, and to radiation image data representing the distribution of irradiation dose. An FPD (Flat Panel Detector) that directly converts and outputs has been put into practical use. It incorporates a panel-type radiation detector such as this FPD, an electronic circuit including an image memory, and a power supply unit, and is output from the radiation detector. A portable radiation detection panel (hereinafter also referred to as an electronic cassette) that stores radiation image data in an image memory has been put into practical use. As the radiation sensitive layer, for example, irradiated radiation is once converted into light by a scintillator (phosphor layer) such as CsI: Tl, GOS (Gd ₂ O ₂ S: Tb), and emitted from the scintillator. There is known a configuration (indirect conversion method) in which light is reconverted into an electric charge and stored by a photodetection unit including a PD (Photodiode) or the like. Because the radiation detection panel is excellent in portability, the subject can be photographed while being placed on a stretcher or bed, and the position of the radiation detection panel can be easily adjusted to adjust the imaging part, so it cannot move. It is possible to flexibly cope with shooting of the subject.

  In relation to the above, Patent Document 1 discloses a sensor having a photoelectric conversion unit having a plurality of photoelectric conversion elements arranged one-dimensionally or two-dimensionally on a substrate, and an electrode extraction unit arranged on the outer periphery of the substrate. A scintillator panel comprising a panel and a scintillator panel made of a phosphor that is disposed on a photoelectric conversion unit and converts radiation into light that can be sensed by a photoelectric conversion element. There is disclosed a technique in which a mechanism for reducing pressure contact between panel surfaces is provided.

  Further, in Patent Document 2, a solid-state light detection means in which solid-state light detection elements are two-dimensionally arranged on a substrate, a sealing means disposed around the entire periphery of the solid-state light detection means, and a sealing means are sandwiched. In the radiation detector having a configuration provided with a cover unit that is disposed on the side opposite to the solid-state light detection unit, and that forms a sealed space together with the solid-state light detection unit and the seal unit, and a scintillator disposed in the sealed space, A technique is disclosed in which the scintillator and the solid-state light detection element are brought into close contact with each other by exhausting the inside of the sealed space, thereby preventing variations in sharpness on the sensor surface.

  Patent Document 3 discloses an X-ray film adhesion holding device that decompresses the space surrounded by the upper lid, the lower lid, and the sealing member, and holds the X-ray film in close contact with the front intensifying screen and the rear intensifying screen. The lower cover is supported by the base so that the lower cover can move upward and downward in a substantially parallel state with respect to the upper cover by the moving mechanism having the link, and can be opened and closed substantially parallel to the upper cover. Has been disclosed that achieves improvement in hermeticity and miniaturization by uniformly adhering to the entire circumference.

Japanese Patent Laid-Open No. 9-257944 JP 2006-337184 A Japanese Patent Laid-Open No. 5-113615

  In the indirect conversion type radiation detection panel, it is necessary to bring the scintillator (light emitting part) and the detection part made of the TFT substrate into close contact with each other. In the manufacture of the radiation detection panel, the two are attached and then housed in the casing of the radiation detection panel. Is done. However, a scintillator made of CsI or the like is formed by vapor-depositing a material on a substrate made of aluminum or the like, while a glass substrate or the like is frequently used as a TFT substrate, and the thermal expansion coefficients of both substrate materials are remarkably different. . For this reason, there has been a problem that deformation such as warping of the substrate occurs with a change in temperature and the detection accuracy of radiation by the radiation detection panel may be lowered.

  In order to solve the above problem, the techniques described in Patent Documents 1 to 3 make the light emission part and the detection part in close contact with each other by setting the inside of the casing to a negative pressure state (decompression state). Since the sensor and the detection unit are not bonded together, it is possible to avoid deformation of the member with a temperature change. However, in the techniques described in Patent Documents 1 to 3, if the airtightness of the housing is impaired due to deterioration of some members or the like, the contact state between the light emitting unit and the detection unit changes, and the radiation detection accuracy Decreases. And, even if the contact state between the light emitting unit and the detection unit changes, no change in appearance occurs, so there may be a situation in which radiation detection is performed without noticing the state in which the detection accuracy of radiation has declined. There's a problem.

  The present invention has been made in consideration of the above facts, and can prevent deformation such as warping of a structural member accompanying a temperature change, and can easily determine whether or not the state is suitable for radiation detection. The purpose is to obtain a panel.

  In order to achieve the above object, a radiation detection panel according to claim 1 is a shape having an upper surface and a bottom surface, and an upper surface side member on which the upper surface is formed and a bottom surface side member on which the bottom surface is formed. A casing that is relatively displaceable so that a distance between the top surface and the bottom surface changes, and a casing that is disposed in the casing and is attached to one of the top surface side member and the bottom surface side member and transmits the subject. A light emitting portion that absorbs radiation emitted to the top surface or the bottom surface and emits light; and is disposed in the casing and attached to the other of the top surface side member and the bottom surface side member, and emits the light. The light emitted from the part is detected, and the first state in contact with the light emitting part or the second state separated from the light emitting part is switched in accordance with the change in the distance between the upper surface and the bottom surface. And a detection unit. It is.

  In the radiation detection panel according to the first aspect of the present invention, the casing has a shape having an upper surface and a bottom surface, and the upper surface side member on which the upper surface is formed and the bottom surface side member on which the bottom surface is formed are formed between the upper surface and the bottom surface. Relative displacement is possible so that the interval changes. In addition, a light emitting portion is disposed in the housing, and the light emitting portion is attached to one of the upper surface side member and the bottom surface side member, and absorbs the radiation that has passed through the subject and has been irradiated on the upper surface or the bottom surface. Release. In addition, a detection unit is also disposed in the housing, and the detection unit is attached to the other of the upper surface side member and the bottom surface side member, detects light emitted from the light emission unit, and determines the distance between the upper surface and the bottom surface. With the change, the state is switched to the first state in contact with the light emitting unit or the second state separated from the light emitting unit.

  Thus, in the first aspect of the present invention, the light emitting portion and the detecting portion are not bonded together, and the upper surface side member and the bottom surface side member are relative to each other so that the distance between the upper surface and the bottom surface of the housing is increased. Since the light emitting unit and the detecting unit are separated from each other in the state (second state), the component member (the light emitting unit or the detecting unit) is prevented from being deformed due to temperature change. Is done. Further, when the upper surface side member and the bottom surface side member are relatively displaced so that the distance between the upper surface and the bottom surface of the housing is reduced, the first state in which the light emitting unit and the detection unit are in contact, that is, radiation It is in a state suitable for detection. Therefore, in the first aspect of the present invention, the distance between the light emitting unit and the detecting unit changes according to the distance between the upper surface and the bottom surface of the housing, and the first state in which the light emitting unit and the detecting unit are in contact with each other. In other words, it can be easily determined from the appearance of the housing (the distance between the top surface and the bottom surface of the housing) whether or not it is in a state suitable for radiation detection. It is possible to prevent the detection of radiation without being noticed.

  When the upper surface side member and the bottom surface side member constituting the housing are relatively displaceable so that the distance between the upper surface and the bottom surface of the housing changes as in the invention of claim 1, Depending on the configuration of the housing, there may be a positional deviation in which the relative position between the light emitting unit and the detecting unit changes in a direction approximately parallel to the top surface and the bottom surface of the housing in accordance with the relative displacement between the upper surface side member and the bottom surface side member. May occur. In consideration of this, in the first aspect of the present invention, for example, as described in the second aspect, the upper surface side member extends over the entire circumference of the outer edge of the upper surface member whose one surface forms the upper surface of the housing. The bottom surface side member has a shape in which the wall portion is erected along a direction approximately perpendicular to the bottom surface, and one surface of the bottom surface member is substantially orthogonal to the bottom surface member over the entire circumference of the outer edge of the bottom surface member forming the bottom surface of the housing. The wall portion is erected along the direction, and the housing has the upper surface member and the bottom surface member facing substantially parallel, and the wall portion of the upper surface side member and the wall portion of the bottom surface side member are It is preferable that the upper surface side member and the bottom surface side member are arranged so as to face each other with a gap along a direction substantially parallel to the upper surface and the bottom surface over the entire circumference.

  According to the second aspect of the present invention, the wall portion of the upper surface side member erected over the entire circumference of the outer edge of the upper surface member, and the wall of the bottom surface side member erected over the entire periphery of the outer edge of the bottom surface member. The portions are along the changing direction of the distance between the upper surface and the bottom surface of the housing. The upper surface side member and the wall surface of the lower surface side member are opposed to each other with a gap along a direction approximately parallel to the upper surface and the bottom surface over the entire circumference of the upper surface member or the bottom surface member. Since the bottom surface side member is disposed, the wall portion of the top surface side member and the wall surface of the bottom surface side member interfere with each other in relative displacement between the top surface side member and the bottom surface side member. It is possible to suppress the relative position of the member from changing in a direction approximately parallel to the upper surface and the bottom surface of the housing. Therefore, according to the second aspect of the present invention, it is possible to suppress the occurrence of the positional deviation between the light emitting portion and the detecting portion due to the relative displacement between the upper surface side member and the bottom surface side member.

  In the invention according to claim 1 or claim 2, for example, as described in claim 3, the light emitting portion has a radiation irradiation surface or a first position in the light emission surface within the irradiation surface. A shielding part is provided for shielding radiation emitted to the first position or light emitted from the first position in the light emitting surface, and the detecting part is constant with respect to the first position in the light receiving surface. It is preferable that a light-shielding portion that shields light irradiated to the second position in the light-receiving surface is provided at the second position in the positional relationship. Thereby, when the detection unit detects the light emitted from the light emitting unit as an image, the position corresponding to the first position on the image detected by the detection unit has a density due to radiation or light shielding by the shielding unit. A change occurs, and a density change also occurs at a position corresponding to the second position on the image due to light shielding by the light shielding portion. For this reason, a positional shift occurs between the light emitting unit and the detecting unit based on whether the positional relationship between the two density changes occurring in the image corresponds to the positional relationship between the first position and the second position. It is possible to determine whether or not, or to detect the direction of displacement and the amount of displacement.

  Further, in the invention according to any one of claims 1 to 3, for example, as described in claim 4, a sealing means for sealing a gap between the upper surface side member and the bottom surface side member, It is preferable to provide communication means for selectively communicating with the outside. By sealing the gap between the upper surface side member and the bottom surface side member by the above-described sealing means, the radiation detection panel according to the present invention can be used for imaging during surgery or sterilized and cleaned as necessary. However, when the gap between the upper surface side member and the lower surface side member is sealed, the air sealed in the internal space of the housing changes so that the distance between the upper surface and the bottom surface of the housing changes. It becomes a resistance when these are displaced relatively. On the other hand, when the communication means for selectively communicating the inside and the outside of the housing is provided, the inside and the outside of the housing are communicated only when the upper surface side member and the bottom surface side member are relatively displaced. Therefore, it is possible to easily displace the upper surface side member and the bottom surface side member relative to each other while maintaining the sealing property of the housing.

  In the invention according to any one of claims 1 to 4, the first state in which the upper surface side member and the lower surface side member are relatively displaced and the light emitting portion and the detecting portion are in contact with each other, or the light emission Switching to the second state in which the part and the detection part are separated from each other includes, for example, a sealing unit that seals a gap between the upper surface side member and the lower surface side member, and an internal space of the housing. A connecting portion for connecting the air pressure generating device so that the air pressure generating device communicates with the air pressure generating device, and the air pressure generated by the air pressure generating device connected to the connecting portion is passed through the connecting portion to the internal space of the housing. It can be realized by introducing. In this case, by introducing a negative pressure into the internal space of the housing, the upper surface side member and the bottom surface side member are relatively displaced in a direction in which the space between the upper surface and the bottom surface of the housing is reduced, and the internal space of the housing By introducing positive pressure into the upper surface member, the upper surface side member and the bottom surface side member are relatively displaced in the direction in which the distance between the upper surface and the bottom surface of the housing increases.

  Moreover, in the invention according to any one of claims 1 to 5, for example, as described in claim 6, the upper surface side member and the bottom surface side member are arranged in a direction in which the interval between the upper surface and the bottom surface of the housing is increased. It is preferable to provide a biasing means for biasing. The upper surface side member and the bottom surface side member are relatively displaced, and switching to the first state in which the light emitting unit and the detecting unit are in contact or the second state in which the light emitting unit and the detecting unit are separated from each other, In addition to introducing air pressure into the internal space of the housing as described in claim 5, the force that relatively displaces the upper surface side member and the lower surface side member by hand or a jig or the like is used. Although it can also be realized by adding to the outer surface of the member, in particular, if the above-described urging means is provided in this aspect, the upper surface side member and the bottom surface side member are moved in the direction in which the distance between the upper surface and the bottom surface of the housing is increased. The relative displacement is preferable because it can be easily realized by the urging force of the urging means.

  Further, in the invention according to any one of claims 1 to 6, for example, as described in claim 7, the upper surface side member and the bottom surface side member are relatively relative to each other in a direction in which the distance between the upper surface and the bottom surface is increased. It is preferable that there is provided holding means for holding the relative position between the upper surface side member and the bottom surface side member at the relative position after the relative displacement when the upper surface side member and the lower surface side member are displaced.

  Maintaining the relative position between the upper surface side member and the lower surface side member is, for example, as described in claim 5, wherein the upper surface side member and the bottom surface side member are relatively displaced by air pressure introduced into the internal space of the housing. If it is an aspect to be made, it can be realized by continuing to introduce air pressure after the upper surface side member and the bottom surface side member are relatively displaced, but the radiation detection panel according to the present invention has portability. In the case of the configuration, there is a problem that the portability is impaired because the connection with the air pressure generation device cannot be released. On the other hand, if the radiation detection panel according to the present invention is provided with the above-described holding means, the top surface side member and the bottom surface side member may be relatively displaced by the air pressure introduced into the internal space of the housing. The connection with the air pressure generator can be released, and the radiation detection panel according to the present invention can be made portable.

  Further, in the invention according to claim 7, a sealing means for sealing a gap between the upper surface side member and the bottom surface side member and a communication means for selectively communicating the inside and the outside of the housing are provided. The holding means communicates the inside and the outside of the housing by the communicating means while the upper surface side member and the bottom surface side member are relatively displaced, as described in claim 8, for example, After the relative displacement between the bottom surface side member and the bottom surface side member, the relative position between the top surface side member and the bottom surface side member is relatively displaced by blocking communication between the inside and outside of the housing by the communication means. It can comprise so that it may hold | maintain in the relative position after.

  Further, in the invention according to any one of claims 1 to 3 to 8, the housing is provided between the upper surface side member and the lower surface side member, for example, as described in claim 9, The gap between the upper surface side member and the bottom surface side member is sealed, and an expansion / contraction member is provided that expands and contracts according to a change in the size of the gap due to relative displacement between the upper surface side member and the bottom surface side member. Also good.

  In the invention according to any one of claims 1 to 9, for example, as described in claim 10, the light emitting portion and the detecting portion are optically arranged between the light emitting portion and the detecting portion. An optical coupling member to be coupled is provided, and in the first state, the detection unit may be configured to contact the light emitting unit via the optical coupling member.

  Further, in the invention according to any one of claims 1 to 10, for example, as described in claim 11, the thickness of the housing in the first state in which the detection unit is in contact with the light emitting unit is irradiated. It is preferable that the size of the cassette is configured to be the same as the thickness of the casing in the cassette configured to record the radiation on the photosensitive material as an image. Thereby, the radiation detection panel according to the present invention can be handled in the same manner as the conventional cassette having the above configuration, and the handleability of the radiation detection panel according to the present invention is improved.

  Further, in the invention according to any one of claims 1 to 11, the detection means is disposed upstream of the light emission direction with respect to the light emitting portion as described in claim 12, for example. Is preferred. As described above, by disposing the detection means upstream of the radiation arrival direction with respect to the light emitting portion, the detection means is disposed more downstream than when the detection means is disposed downstream of the light emission portion in the radiation arrival direction. The amount of received light increases, and the detection sensitivity in the detection means for detecting the light emitted from the light emitting part can be improved.

  As described above, the present invention has a shape having an upper surface and a bottom surface, and the upper surface member on which the upper surface is formed and the lower surface member on which the bottom surface is formed are relatively arranged so that the distance between the upper surface and the bottom surface changes. A housing that is displaceable, a light emitting portion that is disposed in the housing and attached to one of the upper surface side member and the bottom surface side member, absorbs radiation that has passed through the subject, and emits light; and It is arranged and attached to the other of the upper surface side member and the bottom surface side member, detects light emitted from the light emitting portion, and contacts the light emitting portion as the distance between the upper surface and the bottom surface of the housing changes. A detection unit that switches to a first state or a second state that is spaced apart from the light emitting unit, so that deformation such as warping of a component due to a temperature change can be prevented and suitable for detection of radiation It is easy to judge whether or not It has an effect.

It is a perspective view which shows the electronic cassette demonstrated by embodiment partially fractured | ruptured. It is sectional drawing which shows the structure of the electronic cassette concerning 1st Embodiment. (A) is a perspective view which shows the position of the shielding member on the light emission surface of a scintillator, and the light-receiving surface of a radiation detector, (B), (C) is an image figure which shows an example of a radiographic image, respectively. It is a block diagram which shows the principal part structure of the electric system of an electronic cassette. It is a block diagram which shows the principal part structure of the electrical system of a console and a radiation generator. It is sectional drawing which shows the structure of the electronic cassette concerning 2nd Embodiment. It is sectional drawing which shows the structure of the electronic cassette concerning 3rd Embodiment. It is sectional drawing which shows the structure of the electronic cassette concerning 4th Embodiment. It is sectional drawing which shows the structure of the electronic cassette concerning 5th Embodiment. It is a side view which shows the structure of the communication switching part of the electronic cassette concerning 5th Embodiment. It is a block diagram which shows the principal part structure of the electric system of the electronic cassette concerning 5th Embodiment.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows an electronic cassette 10 as an example of a radiation detection panel according to the present invention. The electronic cassette 10 is made of a material that transmits the radiation X, and includes a housing 14 that has an overall shape of approximately a rectangular parallelepiped, and a rectangular upper surface serving as an irradiation surface 12 that is irradiated with the radiation X transmitted through the subject. . In the housing 14, the radiation detection unit (TFT substrate) 42 as the detection means of the present invention and the light emission unit of the present invention are arranged from the irradiation surface 12 side along the arrival direction of the radiation X transmitted through the subject. The scintillators 34 and the like are arranged in order.

  The irradiation surface 12 of the electronic cassette 10 is composed of a plurality of LEDs, and displays the operation state of the electronic cassette 10 such as the operation mode (for example, “ready state” and “data transmitting”) and the remaining battery capacity. A display unit 12A is provided. The display unit 12A may be composed of a light emitting element other than an LED, or may be composed of display means such as a liquid crystal display or an organic EL display. Further, the display unit 12 </ b> A may be provided at a site other than the irradiation surface 12.

  As shown in FIG. 2, the housing 14 of the electronic cassette 10 includes a storage body 16 and a lid body 18. The storage body 16 is made of, for example, ABS resin, and the first side wall 16B along the direction substantially orthogonal to the bottom surface of the housing 14 is formed on the outer edge of the bottom plate 16A having a rectangular shape and one surface forming the bottom surface of the housing 14. The bottom plate 16A has an approximately box-like shape standing over the entire periphery of the outer edge. The lid 18 is also rectangular and has a second side wall along the outer edge of the top plate 18 </ b> A whose one surface forms the upper surface (irradiation surface 12) of the housing 14 and in a direction approximately perpendicular to the upper surface of the housing 14. 18B is an approximately box-shaped shape that is erected over the entire circumference of the outer edge of the top plate 18A. The second side wall 18B of the lid 18 is made of, for example, ABS resin, and the top plate 18A is made of, for example, carbon. Thereby, the intensity | strength of the top plate 18A is ensured, suppressing absorption of the radiation X by the top plate 18A.

  In the embodiment, “upper” means the direction on the top plate 18A side when viewed from the bottom plate 16A side, and “lower” means the direction on the bottom plate 16A side when viewed from the top plate 18A side.

  Further, the top plate 18A of the lid body 18 is larger in size than the bottom plate 16A of the storage body 16, and the housing 14 is covered with the opening portion of the storage body 16 by the top plate 18A of the lid body 18. The fitting body 16 and the lid body 18 are fitted together so that the second side wall 18B of the lid body 18 located on the outer peripheral side of the first side wall 16B of the 16 faces the first side wall 16B with a gap. It is structured. As a result, the top surface and the bottom surface of the housing 14 are approximately parallel. The housing 14 is relatively displaceable along the thickness direction of the housing 14 (the arrival direction of the radiation X) in which the housing body 16 and the lid body 18 are approximately orthogonal to the upper surface and the bottom surface of the housing 14. As the storage body 16 and the lid body 18 are relatively displaced, the thickness of the housing 14 changes as is apparent from a comparison between FIGS. 2 (A) and 2 (B).

  The casing 14 having the above configuration is an example of a casing according to claim 2. The storage body 16 is an example of a bottom surface side member of the present invention (more specifically, a bottom surface side member according to claim 2), the bottom plate 16A is an example of the bottom surface member of claim 2, and the first side wall 16B is It is an example of the wall part of the bottom face side member of Claim 2. The lid 18 is an example of the upper surface side member of the present invention (more specifically, the upper surface side member described in claim 2), and the top plate 18A is an example of the upper surface member of claim 2, and the second side wall 18B. These are an example of the wall part of the upper surface side member of Claim 2.

  In addition, a protrusion 16C that protrudes toward the outside of the storage body 16 is provided at the upper end portion of the first side wall 16B of the storage body 16, and is separated from the lower end portion of the second side wall 18B of the lid body 18 by a predetermined distance. At the position, a protrusion 18 </ b> C that protrudes toward the inside of the lid 18 is provided. Thereby, the relative displacement between the housing body 16 and the lid body 18 in the direction in which the upper surface and the bottom surface of the housing 14 are separated from each other is a position where the protrusion 16C and the protrusion 18C abut (the position shown in FIG. 2A ( It is limited to the maximum thickness state))). The relative displacement between the housing 16 and the lid 18 in the direction in which the upper surface and the bottom surface of the housing 14 approach each other is such that the upper end of the first side wall 16B of the housing 16 contacts the top plate 18A of the lid 18. The position is limited to the contact position (the position shown in FIG. 2B (referred to as the minimum thickness state)). The thickness of the casing 14 in this state is the same size as the thickness of the casing in a conventional cassette configured to record the irradiated radiation as an image on the photosensitive material. Corresponding configuration).

  Further, in the electronic cassette 10 according to the present embodiment, the radiation detection unit (TFT substrate) 42 and the scintillator 34 disposed in the housing 14 are not bonded together, and the radiation detection unit (TFT substrate) 42 is the lid 18. The scintillator 34 is formed on a support substrate 36, and is attached to the top plate 18 A (the back surface (surface opposite to the irradiation surface 12)) of the storage board 16. It is attached to the upper surface of the top plate of the base 40 attached to the bottom plate 16A. For this reason, the distance between the radiation detection unit (TFT substrate) 42 and the scintillator 34 changes according to the relative displacement between the storage body 16 and the lid 18, and the casing 14 has the maximum thickness as shown in FIG. In the case of the state, the radiation detection unit (TFT substrate) 42 and the scintillator 34 are separated from each other by a predetermined distance. When the casing 14 is in the minimum thickness state as shown in FIG. (TFT substrate) 42 and scintillator 34 are in close contact with each other. A control substrate 46 is attached to the lower surface of the top plate of the base 40, and the control substrate 46 and the radiation detection unit (TFT substrate) 42 are electrically connected via a flexible cable 48.

  In the present embodiment, when the casing 14 is in the minimum thickness state, the upper end portion of the first side wall 16B of the storage body 16 abuts on the top plate 18A of the lid 18 and the radiation detection unit (TFT substrate). 42 and the scintillator 34 are in close contact with each other, but it is not essential that the upper end portion of the first side wall 16B of the storage body 16 abuts on the top plate 18A of the lid body 18. The relative displacement between the storage body 16 and the lid 18 in the direction in which the bottom surface and the bottom surface approach each other is limited to a position where the radiation detector (TFT substrate) 42 and the scintillator 34 come into close contact with each other, and in this minimum thickness state The upper end portion of the first side wall 16B of the storage body 16 may not be in contact with the top plate 18A of the lid body 18.

  A seal member 20 that is in close contact with the first side wall 16B of the storage body 16 is attached to a position corresponding to the inside of the lid body 18 in the lower end portion of the second side wall 18B of the lid body 18. As shown in FIGS. 2A and 2B, the seal member 20 maintains a state of being in close contact with the first side wall 16 </ b> B even when the storage body 16 and the lid body 18 are relatively displaced. As described above, the gap between the first side wall 16B of the storage body 16 and the second side wall 18B of the lid body 18 is sealed by the sealing member 20, so that the waterproof and airtightness of the internal space of the housing 14 is ensured. Therefore, it becomes possible to use the electronic cassette 10 according to the present embodiment for photographing at the time of surgery where blood or other bacteria may adhere, or to sterilize and wash as necessary. The sealing member 20 is an example of a sealing means according to claims 4, 5 and 8.

  Further, a connection portion 22 for connecting the electronic cassette 10 to the air pressure generator 28 is provided at a position near the bottom plate 16A in the first side wall 16B of the storage body 16. A hole for communicating the inside of the housing 14 with the outside of the housing 14 is formed in the connection portion 22. The hose 30 connected to the air pressure generator 28 is connected to the outside of the housing 14 with respect to this hole. A connector 24 to be fitted to the connector 32 attached to the distal end portion is attached, and a valve 26 that is normally closed and opened only while the pin 26A is pressed is provided inside the housing 14. Installed. The pin 26 </ b> A of the valve 26 protrudes toward the connector 24, and a pressing portion 32 </ b> A that presses the pin 26 </ b> A while being fitted to the connector 24 is provided inside the connector 32.

  Thus, when the connector 24 and the connector 32 are fitted, the pin 26A is pressed by the pressing portion 32A and the valve 26 is opened, so that the internal space of the housing 14 generates air pressure via the hose 30. In communication with the device 28. In this embodiment, the negative pressure or the positive pressure is supplied to the internal space of the housing 14 by the air pressure generator 28 in this state, so that the top surface and the bottom surface of the housing 14 approach each other or the top surface and the bottom surface are moved. The storage body 16 and the lid body 18 are relatively displaced in the direction of separation. When the fitting between the connector 24 and the connector 32 is released, the pressure of the pin 26A by the pressing portion 32A is also released, so that the valve 26 returns to the closed state, and the internal space of the housing 14 and the air pressure generator 28 are restored. Communication with the outside such as is also cut off.

  The connection portion 22 is an example of a connection portion described in claim 5, the valve 26 is an example of communication means described in claims 4 and 8, and the pressing portion 32A of the connector 32 is claimed in claim 7 (specifically, claims). It is an example of the holding means as described in 8).

Further, the scintillator 34 absorbs the radiation X irradiated to the irradiation surface 12 of the casing 14 that has passed through the subject and transmitted through the top plate 18A and the radiation detection unit (TFT substrate) 42 of the lid 18. Emit light. As the scintillator 34, for example, CsI: Tl, CsI: Na (sodium-activated cesium iodide), CsBr, GOS (Gd ₂ O ₂ S: Tb) can be used, but the material is not limited to these materials. . When CsI or the like is used as the scintillator 34, it is preferable that the scintillator 34 has a columnar crystal structure portion. Thereby, the light generated by the scintillator 34 absorbing the radiation is emitted by being guided to the gap between the columnar crystals and being emitted to the radiation detection unit (TFT substrate) 42 side in the columnar crystal structure portion. Therefore, the blur of the radiation image detected by the electronic cassette 10 can be suppressed.

  Further, when CsI or the like is used as the scintillator 34, it is necessary to perform vapor deposition for forming the scintillator 34. Therefore, the support substrate 36 is preferably made of a material having high heat resistance. Is preferred. On the other hand, when GOS is used as the scintillator 34, vapor deposition is not necessary for forming the scintillator 34. Therefore, a material having low heat resistance, such as a synthetic resin, can be used as the support substrate 36.

  In the present embodiment, as shown in FIG. 3A as an example, the surface of the scintillator 34 facing the radiation detection unit (TFT substrate) 42 (irradiation / light emission surface that emits light X and emits light). The shielding member 38 which shields at least one of the radiation irradiated to an irradiation / light emission surface and the light emitted from an irradiation / light emission surface is provided in the edge part.

  The radiation detection unit 42 detects light emitted from the scintillator 34 as an image. As shown in FIG. 4, the photoelectric detection unit 50 including a photodiode (PD: PhotoDiode), a thin film transistor (TFT: Thin). The pixel unit 54 having a film transistor 52 and a storage capacitor (in this embodiment, the electrode pair constituting the photoelectric conversion unit 50 functions as a storage capacitor) has a flat plate shape and a rectangular outer shape in plan view. A plurality of TFT active matrix substrates (hereinafter referred to as “TFT substrates”) formed in a matrix on the insulating substrate 56 are used.

  In the present embodiment, as shown in FIG. 3A as an example, of the surface facing the scintillator 34 of the radiation detection unit (TFT substrate) 42 (the light receiving surface that receives light emitted from the scintillator 34), A light shielding member 58 for shielding light irradiated on the irradiation surface is provided at a position (end) corresponding to the arrangement position of the shielding member 38 on the irradiation / light emission surface of the scintillator 34.

  In the present embodiment, the radiation detection unit (TFT substrate) 42 is disposed on the radiation irradiation surface side of the scintillator 34. However, the light emission unit (scintillator) and the detection unit (radiation detection unit) have such a positional relationship. The method of disposing is referred to as “back surface irradiation” (configuration corresponding to the invention of claim 12). `` Backside irradiation '' means that the amount of light received by the detection unit (radiation detection unit) is smaller than that of `` front side irradiation '' where the detection unit (radiation detection unit) is placed on the opposite side of the radiation irradiation surface of the light emitting unit (scintillator). As a result, the sensitivity of the radiation detection panel (electronic cassette) is improved.

  The photoelectric conversion unit 50 is configured such that a photoelectric conversion film that absorbs light emitted from the scintillator 34 and generates a charge corresponding to the absorbed light is disposed between the upper electrode and the lower electrode. The material constituting the photoelectric conversion film may be any material that absorbs light and generates electric charge. For example, amorphous silicon, an organic photoelectric conversion material, or the like can be used. When the photoelectric conversion film is composed of amorphous silicon, the light emitted from the scintillator 34 can be configured to absorb over a wide wavelength range. However, since it is necessary to perform vapor deposition for forming a photoelectric conversion film made of amorphous silicon, it is necessary to use a substrate having high heat resistance, such as a glass substrate, as the insulating substrate 56.

  On the other hand, when the photoelectric conversion film is composed of an organic photoelectric conversion material, an absorption spectrum showing high absorption mainly in the visible light region is obtained, and absorption of electromagnetic waves other than light emitted from the scintillator 34 by the photoelectric conversion film is obtained. Since it almost disappears, it is possible to suppress noise generated when radiation such as X-rays and γ-rays is absorbed by the photoelectric conversion film. In addition, a photoelectric conversion film made of an organic photoelectric conversion material can be formed by adhering an organic photoelectric conversion material onto a target body using a droplet discharge head such as an inkjet head. Heat resistance is not required.

  Examples of organic photoelectric conversion materials applicable to the photoelectric conversion film include quinacridone-based organic compounds and phthalocyanine-based organic compounds. For example, since the absorption peak wavelength in the visible region of quinacridone is 560 nm, when quinacridone is used as the organic photoelectric conversion material and CsI (Ti) is used as the material of the scintillator 34, the difference between the peak wavelengths is within 5 nm. Thus, the amount of charge generated in the photoelectric conversion film can be substantially maximized. The organic photoelectric conversion material applicable to the photoelectric conversion film is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, and thus the description thereof is omitted.

In the TFT 52, a gate electrode, a gate insulating film, and an active layer (channel layer) are stacked, and a source electrode and a drain electrode are formed on the active layer with a gap therebetween. The active layer is made of an amorphous oxide. As the amorphous oxide constituting the active layer, an oxide containing at least one of In, Ga, and Zn (for example, an In—O system) is preferable, and at least two of In, Ga, and Zn are used. Oxides containing (for example, In—Zn—O, In—Ga, and Ga—Zn—O) are more preferable, and oxides including In, Ga, and Zn are particularly preferable. As the In—Ga—Zn—O-based amorphous oxide, an amorphous oxide whose composition in a crystalline state is represented by InGaO ₃ (ZnO) _m (m is a natural number less than 6) is preferable, and InGaZnO is particularly preferable. ₄ is more preferable. When the active layer of the TFT 52 is formed of an amorphous oxide, it does not absorb radiation such as X-rays or γ-rays, or even if it is absorbed, the amount of noise remains very small. .

  The insulating substrate 56 may be any substrate that absorbs little radiation. Here, both the amorphous oxide constituting the active layer of the TFT 52 and the organic photoelectric conversion material constituting the photoelectric conversion film of the photoelectric conversion unit 50 can be formed at a low temperature. Therefore, the insulating substrate 56 is not limited to a substrate having high heat resistance such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate made of synthetic resin, aramid, or bionanofiber can also be used. Specifically, flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), etc. A conductive substrate can be used. By using such a flexible substrate made of synthetic resin, it is possible to reduce the weight, which is advantageous for carrying around, for example. The insulating substrate 56 includes an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be provided.

  Since aramid can be applied at a high temperature process of 200 ° C. or more, the transparent electrode material can be cured at a high temperature to reduce the resistance, and can be applied to automatic mounting of a driver IC including a solder reflow process. Moreover, since aramid has a thermal expansion coefficient close to that of ITO (indium tin oxide) or a glass substrate, there is little warping after manufacturing and it is difficult to break. In addition, aramid can make a substrate thinner than a glass substrate or the like. Note that the insulating substrate 56 may be formed by stacking an ultrathin glass substrate and aramid.

  The bionanofiber is a composite of a cellulose microfibril bundle (bacterial cellulose) produced by bacteria (Acetobacter Xylinum) and a transparent resin. The cellulose microfibril bundle has a width of 50 nm and a size of 1/10 of the visible light wavelength, and has high strength, high elasticity, and low thermal expansion. By impregnating and curing a transparent resin such as an acrylic resin or an epoxy resin in bacterial cellulose, a bio-nanofiber having a light transmittance of about 90% at a wavelength of 500 nm can be obtained while containing 60-70% of the fiber. Bionanofiber has a low coefficient of thermal expansion (3-7ppm) comparable to silicon crystals, and is as strong as steel (460MPa), highly elastic (30GPa), and flexible, compared to glass substrates, etc. The insulating substrate 56 can be thinned.

  Further, as shown in FIG. 4, the radiation detection unit (TFT substrate) 42 has a plurality of gate wirings 60 extending in a certain direction (row direction) for turning on / off individual TFTs 52, and the certain constants. A plurality of lines extending along the direction (column direction) intersecting the direction and for reading out the charge accumulated in the storage capacitor (between the upper electrode and the lower electrode of the photoelectric conversion unit 50) through the TFT 52 in the on state. Data wiring 62 is provided.

  Individual gate lines 60 of the radiation detection unit 42 are connected to a gate line driver 64, and individual data lines 62 are connected to a signal processing unit 66. When the electronic cassette 10 is irradiated with radiation that has passed through the subject (radiation that carries image information of the subject), radiation corresponding to each position on the irradiation / light emission surface of the scintillator 34 is emitted from each position. A light amount corresponding to the irradiation amount is emitted, and the photoelectric conversion unit 50 of each pixel unit 54 generates a charge having a magnitude corresponding to the light amount emitted from the corresponding part of the scintillator 34. This electric charge is accumulated in the storage capacitor of each pixel unit 54 (between the upper electrode and the lower electrode of the photoelectric conversion unit 50).

  When charges are accumulated in the storage capacitors of the individual pixel portions 54 as described above, the TFTs 52 of the individual pixel portions 54 are sequentially supplied in units of rows by signals supplied from the gate line driver 64 via the gate wiring 60. The charges stored in the storage capacitor of the pixel unit 54 that is turned on and the TFT 52 is turned on are transmitted as an analog electric signal through the data wiring 62 and input to the signal processing unit 66. Therefore, the charges accumulated in the accumulation capacitors of the individual pixel portions 54 are sequentially read out in units of rows.

  The signal processing unit 66 includes an amplifier and a sample hold circuit provided for each data wiring 62, and an electric signal transmitted through each data wiring 62 is amplified by the amplifier and then held in the sample hold circuit. The In addition, a multiplexer and an A / D (analog / digital) converter are connected in order to the output side of the sample and hold circuit, and the electrical signals held in the individual sample and hold circuits are sequentially (serially) input to the multiplexer. The digital image data is converted by an A / D converter. The gate line driver 64 and the signal processing unit 66 described above and the components of the electronic cassette 10 described below are mounted on the control board 46, respectively.

  An image memory 68 is connected to the signal processing unit 66, and image data output from the A / D converter of the signal processing unit 66 is stored in the image memory 68 in order. The image memory 68 has a storage capacity capable of storing image data for a plurality of frames. Every time a radiographic image is captured, the image data obtained by the imaging is sequentially stored in the image memory 68.

  The image memory 68 is connected to a cassette control unit 70 that controls the operation of the entire electronic cassette 10. The cassette control unit 70 includes a microcomputer, and includes a CPU 70A, a memory 70B including a ROM and a RAM, a nonvolatile storage unit 70C including an HDD (Hard Disk Drive), a flash memory, and the like.

  A wireless communication unit 72 is connected to the cassette control unit 70. The wireless communication unit 72 corresponds to a wireless local area network (LAN) standard represented by IEEE (Institute of Electrical and Electronics Engineers) 802.11a / b / g / n, etc. Control the transmission of various information between them. The cassette control unit 70 can wirelessly communicate with a console 80 (described later) via the wireless communication unit 72, and can transmit and receive various types of information to and from the console 80.

  The cassette control unit 70 is connected to a displacement detection unit 76 that detects the displacement between the housing body 16 and the lid 18 of the housing 14, and the detection result by the displacement detection unit 76 is input to the cassette control unit 70. The The displacement detector 76 may be configured to detect at least whether or not the housing body 16 of the housing 14 and the lid body 18 are in a positional relationship corresponding to the minimum thickness state. Although it can be configured by a limit switch or the like that detects whether or not the upper end portion of the side wall 16B is in contact with the top plate 18A of the lid 18, the present invention is not limited to this. It is also possible to comprise a linear encoder or the like that can continuously detect the relative position between the cover 18 and the lid 18.

  The electronic cassette 10 is provided with a power supply unit 74, and the various electronic circuits (gate line driver 64, signal processing unit 66, image memory 68, wireless communication unit 72, cassette control unit 70, etc.) described above are power supply units. 74 are connected to each other (not shown), and are operated by electric power supplied from the power supply unit 74. The power supply unit 74 incorporates a battery (secondary battery) so as not to impair the portability of the electronic cassette 10, and supplies power from the charged battery to various electronic circuits.

  As shown in FIG. 5, the console 80 is composed of a computer, the CPU 104 that controls the operation of the entire apparatus, the ROM 106 that stores various programs including a control program in advance, the RAM 108 that temporarily stores various data, and various data Are connected to each other via a bus. In addition, a communication I / F unit 132 and a wireless communication unit 118 are connected to the bus, the display 100 is connected via the display driver 112, and the operation panel 102 is further connected via the operation input detection unit 114. .

  The communication I / F unit 132 is connected to the radiation generator 84 via the connection terminal 80A, the communication cable 82, and the connection terminal 84A. The console 80 (the CPU 104 thereof) transmits / receives various information such as exposure conditions to / from the radiation generation apparatus 84 via the communication I / F unit 132. The wireless communication unit 118 has a function of performing wireless communication with the wireless communication unit 72 of the electronic cassette 10, and the console 80 (CPU 104 thereof) transmits and receives various information such as image data to and from the electronic cassette 10. 118. Further, the display driver 112 generates and outputs signals for displaying various information on the display 100, and the console 80 (CPU 104 of the console 80) displays an operation menu, a captured radiation image, and the like on the display 100 via the display driver 112. Display. The operation panel 102 includes a plurality of keys, and various information and operation instructions are input. The operation input detection unit 114 detects an operation on the operation panel 102 and notifies the CPU 104 of the detection result.

  Further, the radiation generator 84 includes a communication I / F unit 132 that transmits and receives various information such as an exposure condition between the radiation source 130 and the console 80, and an exposure condition (this exposure) received from the console 80. And a radiation source controller 134 for controlling the radiation source 130 based on the condition (including information on tube voltage and tube current).

  Next, the operation of this embodiment will be described. In the electronic cassette 10 according to the present embodiment, the radiation detection unit (TFT substrate) 42 and the scintillator 34 are not bonded to each other, and the housing 14 is stored in FIG. The maximum thickness state shown in (A) is maintained, and the radiation detector (TFT substrate) 42 and the scintillator 34 are maintained in a state of being separated by a predetermined distance. For this reason, even if the coefficient of thermal expansion of the material constituting the TFT substrate of the radiation detection unit 42 and the material constituting the support substrate 36 of the scintillator 34 are significantly different, warping of any of the substrates with a change in temperature, etc. Is prevented from occurring. In addition, since the casing 14 is in the maximum thickness state, an administrator of the electronic cassette 10 (for example, a radiation engineer) is in a state in which the electronic cassette 10 is suitable for storage (a radiation detection unit (TFT substrate) 42 and a scintillator). 34 can be easily recognized from the appearance (thickness dimension) of the housing 14.

  Since the connector 32 is not fitted to the connector 24 while the electronic cassette 10 is stored without being used for photographing, the valve 26 is maintained in a closed state, and the air in the housing 14 is kept in the housing 14. The sealed state is maintained. Thus, even when an external force is applied to reduce the thickness of the housing 14 while the electronic cassette 10 is stored without being used for photographing, the external force is resisted by the air sealed in the housing 14. As a result of the reaction force, the thickness of the housing 14 is prevented from changing, and the radiation detection unit (TFT substrate) 42 and the scintillator 34 are maintained apart from each other.

  When radiographing is performed using the electronic cassette 10, a photographer (for example, a radiographer or the like) uses the connector 32 attached to the tip of the hose 30 for radiographing as preparation work for radiographic imaging. The electronic cassette 10 used for photographing is connected to the air pressure generator 28 by being fitted to the connector 24 of the electronic cassette 10 to be generated, and then the air pressure generator 28 generates a negative pressure. Thereby, first, the pin 26A of the valve 26 is pressed by the pressing portion 32A of the connector 32, and the valve 26 is switched to the open state, whereby the internal space of the housing 14 is communicated with the air pressure generator 28 via the hose 30. . Then, the negative pressure generated by the air pressure generator 28 is introduced into the internal space of the housing 14, so that the housing 14 has the housing 16 and the lid in a direction in which the upper surface and the bottom surface of the housing 14 approach each other. 18 is displaced relatively to the minimum thickness state shown in FIG. 2B (the thickness is the same as the thickness of the casing in the conventional cassette), and the radiation detector (TFT substrate) 42 and the scintillator 34 are placed over the entire surface. It adheres over.

  The housing 14 of the electronic cassette 10 is fitted with the housing body 16 and the lid body 18 so that the first side wall 16B of the housing body 16 and the second side wall 18B of the lid body 18 face each other with a gap therebetween. It is a fitting structure. A seal member 20 is also provided in the gap between the first side wall 16B and the second side wall 18B. For this reason, even when the storage body 16 and the lid body 18 are relatively displaced in the direction in which the upper surface and the bottom surface of the housing 14 approach each other, the storage body 16 and the lid body 18 are approximately parallel to the upper surface and the bottom surface. Relative displacement in the direction is suppressed, and the radiation detector (TFT substrate) 42 and the scintillator 34 are in close contact with each other in a substantially fixed positional relationship.

  When the casing 14 is in the minimum thickness state, the photographer is in a state where the electronic cassette 10 is suitable for photographing (a state where the radiation detection unit (TFT substrate) 42 and the scintillator 34 are in close contact with each other). Recognizing this from the appearance (thickness dimension) of the housing 14 and releasing the fitting between the connector 24 and the connector 32, the connection between the electronic cassette 10 and the air pressure generator 28 is released. Thereby, the pressing of the pin 26A of the valve 26 by the pressing portion 32A of the connector 32 is released, and the valve 26 is switched to the closed state, so that the air in the housing 14 is sealed in the housing 14. Therefore, even when an external force is applied to increase the thickness of the casing 14 while the electronic cassette 10 is used for photographing, a reaction force against the external force is generated by the air sealed in the casing 14. As a result, the thickness of the housing 14 is prevented from changing, and the radiation detection unit (TFT substrate) 42 and the scintillator 34 are maintained in close contact with each other.

  Then, the photographer places the electronic cassette 10 in which the casing 14 is in the minimum thickness state (the thickness of the casing 14 is the same as the thickness of the casing in the conventional cassette) in the position / orientation corresponding to the current imaging region. Deploy. Thereby, the preparation work for radiographic imaging is completed.

  On the other hand, in the electronic cassette 10, when the casing 14 is in the minimum thickness state, the displacement detection unit 76 detects that the casing 14 is in the minimum thickness state, and the detection result is output to the cassette control unit 70. In the cassette control unit 70, when the displacement detection unit 76 detects that the casing 14 is in the minimum thickness state, the cassette ID of the own cassette stored in the storage unit 70C is read, and the read out cassette's cassette ID is read out. The cassette ID is transmitted to the console 80 through the wireless communication unit 72 together with a preparation completion signal indicating that the photographing is ready.

  When the console 80 receives the cassette ID and the preparation completion signal from the electronic cassette 10, the console 80 transmits an instruction signal for instructing the start of exposure to the radiation generation apparatus 84 after registering the received cassette ID in the HDD 110 or the like. As a result, the radiation generator 84 emits radiation from the radiation source 130.

  The radiation emitted from the radiation source 130 passes through the subject and is irradiated onto the irradiation surface 12 of the electronic cassette 10, passes through the top plate 18 </ b> A of the lid 18 and the radiation detection unit (TFT substrate) 42, and is applied to the scintillator 34. The light emitting surface is irradiated. The scintillator 34 absorbs radiation applied to the irradiation / light emission surface and emits light of a light amount corresponding to the absorbed radiation dose. A shielding member 38 is provided at the end of the irradiation / light emission surface of the scintillator 34. Therefore, at least one of the radiation and light applied to the shielding member 38 is shielded by the shielding member 38. Thereby, in the radiographic image image | photographed using the electronic cassette 10, the mark corresponding to the shielding member 38 appears in an edge part.

  The light emitted from the scintillator 34 is applied to the light receiving surface of the radiation detecting unit (TFT substrate) 42, and the radiation detecting unit (TFT substrate) 42 detects the light applied to the light receiving surface as an image. Since the light shielding member 58 is provided at the end of the light receiving surface of the portion (TFT substrate) 42, the light irradiated to the light shielding member 58 is shielded by the light shielding member 58. Thereby, in the radiographic image image | photographed using the electronic cassette 10, the mark corresponding to the light shielding member 58 also appears in an edge part.

  In the present embodiment, a light shielding member 58 is provided at a position corresponding to the arrangement position of the shielding member 38 on the irradiation / light emission surface of the scintillator 34 in the light receiving surface of the radiation detection unit (TFT substrate) 42. For this reason, when the radiation detection part (TFT substrate) 42 and the scintillator 34 are in close contact with each other in a state where there is no positional shift in a direction approximately parallel to the top surface and bottom surface of the housing 14, as an example, FIG. As shown in A), the mark corresponding to the shielding member 38 and the mark corresponding to the shielding member 58 overlap on the radiation image. In addition, when the radiation detector (TFT substrate) 42 and the scintillator 34 are in close contact with each other in the case where there is a positional shift in a direction approximately parallel to the upper surface or the bottom surface of the housing 14, an example is shown in FIG. As described above, a deviation occurs between the mark position corresponding to the shielding member 38 and the mark position corresponding to the light shielding member 58.

  Thus, the radiographer visually recognizes the radiographic image displayed on the display 110 based on the radiographic image data transmitted from the electronic cassette 10 to the console 80, so that the radiation detection unit (TFT substrate) 42, the scintillator 34, It is possible to confirm the presence or absence of misalignment. If the photographer determines that the positional deviation has occurred, the photographer reconnects the air pressure generator 28 to the electronic cassette 10 to return the housing 14 to the minimum thickness state after the housing 14 is once set to the maximum thickness state, etc. In addition, it is possible to take measures to eliminate the positional deviation.

  The positional relationship between the shielding member 38 and the shielding member 58 is not limited to the positional relationship in which the corresponding marks overlap on the radiation image in a state where no positional deviation occurs, and the shape is as shown in FIG. It is not limited to a rectangular shape. The shape / position relationship between the shielding member 38 and the shielding member 58 may be changed as appropriate as long as the presence / absence of the positional deviation can be confirmed by viewing the radiation image.

  Further, the positional deviation between the radiation detection unit (TFT substrate) 42 and the scintillator 34 is a problem when performing image processing such as correcting the radiation image according to the variation in the light emission efficiency within the irradiation / light emission surface of the scintillator 34. become. For this reason, the shielding member 38 and the shielding member 58 can detect the direction and the amount of positional deviation between the radiation detector (TFT substrate) 42 and the scintillator 34 instead of the rectangular shape as shown in FIG. As such, the shapes may be different. In this case, based on the detection result, correction data for detecting the direction and amount of positional deviation based on the positional relationship between the marks on the radiographic image, and correcting variations in the light emission efficiency of the scintillator 34 in units of pixels. What is necessary is just to correct | amend relatively with respect to a radiographic image. Thereby, it is possible to omit taking measures for eliminating the positional deviation.

  When the radiographic image capturing is completed, the photographer reconnects the electronic cassette 10 to the air pressure generator 28, and the air pressure generator 28 generates a positive pressure. Thereby, the internal space of the housing 14 is communicated with the air pressure generator 28 via the hose 30. Further, the positive pressure generated by the air pressure generator 28 is introduced into the internal space of the housing 14, so that the storage body 16 and the lid 18 are relatively moved in a direction in which the upper surface and the bottom surface of the housing 14 are separated from each other. Displaced. As a result, the housing 14 returns to the maximum thickness state suitable for storing the electronic cassette 10 (see FIG. 2A).

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 6, the electronic cassette 150 according to the second embodiment is the electronic cassette described in the first embodiment in that an optical coupling member 152 is provided on the light receiving surface of the radiation detection unit (TFT substrate) 42. It is different from the cassette 10. In the second embodiment, when the casing 14 is in the minimum thickness state, the scintillator 34 and the radiation detection unit (TFT substrate) 42 are in close contact via the optical coupling member 152 (the state shown in FIG. 6B). The optical coupling member 152 optically couples the scintillator 34 and the radiation detection unit (TFT substrate) 42 in this state. In this embodiment, the optical coupling member 152 is made of a flexible material such as gel or oil coupling.

  In the electronic cassette 150 according to the second embodiment, since the optical coupling member 152 is provided, the light detection efficiency by the radiation detection unit (TFT substrate) 42 that detects the light emitted from the scintillator 34 is improved. The radiation detection sensitivity is improved as compared with the electronic cassette 10 described in the first embodiment. The optical coupling member 152 is an example of the optical coupling member according to claim 10.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment and 2nd Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 7, in the electronic cassette 154 according to the third embodiment, the support substrate 36 on which the scintillator 34 is formed is such that the top plate 18A of the lid 18 (the back surface (the surface opposite to the irradiation surface 12)). ) Through a spacer 44. The radiation detector (TFT substrate) 42 having the light coupling member 152 on the light receiving surface is attached to the top surface of the top plate of the base 40. In the electronic cassette 154 according to the third embodiment, the radiation detection unit (TFT substrate) 42 is located on the opposite side to the radiation irradiation surface of the scintillator 34 and has a positional relationship corresponding to “surface irradiation”. For this reason, the electronic cassette 10 described in the first embodiment and the electronic cassette 150 described in the second embodiment (the electronic cassette having a positional relationship in which the radiation detection unit (TFT substrate) 42 and the scintillator 34 correspond to “backside irradiation”). However, the present invention includes such a configuration within the scope of the right.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment and 2nd Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 8, in the electronic cassette 156 according to the fourth embodiment, the top plate 18A of the lid 18 is approximately the same size as the bottom plate 16A of the storage body 16, and in the first to third embodiments, The protrusion 18C provided on the second side wall 18B of the lid 18 is omitted. Further, in the first to third embodiments, between the protrusion 16C provided on the upper end portion of the first side wall 16B of the storage body 16, and the second side wall 18B of the lid 18 and the first side wall 16B of the storage body 16. Also, the seal member 20 provided in the is omitted.

  Between the lower end of the second side wall 18B of the lid 18 and the upper end of the first side wall 16B of the storage body 16, a bellows-like elastic member 158 is provided over the entire circumference of the side surface of the housing 14. It has been. The expandable member 158 has an upper end that is in close contact with the lower end of the second side wall 18B of the lid 18 and a lower end that is in close contact with the upper end of the first side wall 16B of the storage body 16. The interior space is waterproof and airtight. The sealing member 20 is an example of a sealing means according to claims 4, 5, and 8 and an example of an expansion / contraction member according to claim 9.

  In the electronic cassette 156 according to the fourth embodiment, the storage body 16 and the lid 18 are closer to the top surface and the bottom surface of the housing 14 than the electronic cassettes described in the first to third embodiments. When relatively displaced, the storage body 16 and the lid body 18 are relatively easily displaced in a direction approximately parallel to the top surface and the bottom surface, and the positional deviation between the radiation detection unit (TFT substrate) 42 and the scintillator 34 is displaced. Such a configuration is also included in the scope of the right of the present invention although it is likely to occur.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the part same as 1st-3rd embodiment, and description is abbreviate | omitted.

  As shown in FIG. 9, the connection part 22 is omitted from the electronic cassette 160 according to the fifth exemplary embodiment. Further, a compression coil spring 162 that urges the storage body 16 and the cover body 18 in a direction in which the upper surface and the bottom surface of the housing 14 are separated from each other is provided between the bottom plate 16A of the storage body 16 and the top plate 18A of the cover body 18. Are provided at a plurality of locations in the housing 14. The compression coil spring 162 is an example of an urging means according to claim 6.

  As shown in FIG. 10, in the electronic cassette 160 according to the fifth embodiment, a hole 164 having a tapered inclined surface is formed in the bottom plate 16A of the housing 16 (see FIG. 10B). ), A communication switching portion 166 is provided at a position corresponding to the hole 164. The communication switching unit 166 includes a plug member 168 having a tapered inclined surface like the hole 164, and an actuator 170 made of a solenoid or the like that moves the plug member 168 in a direction substantially perpendicular to the bottom plate 16A. Yes.

  When the actuator 170 is not energized, a biasing force of a biasing means (not shown) causes the plug member 168 to enter the hole 164 and the inclined surface of the plug member 168 closely contacts the inclined surface of the hole 164 (FIG. 10 ( The stopper member 168 is positioned at A). In this state, communication between the internal space of the housing 14 and the outside of the housing 14 is blocked, and the air in the housing 14 is sealed in the housing 14. When the actuator 170 is energized, the plug member 168 is detached from the hole 164 against the urging force of the urging means, and the inclined surface of the plug member 168 is separated from the inclined surface of the hole 164. The stopper member 168 is moved to a position (see FIG. 10A). In this state, the internal space of the housing 14 communicates with the outside of the housing 14.

  As shown in FIG. 11, the communication switching unit 166 is connected to the cassette control unit 70, and the operation of the actuator 170 of the communication switching unit 166 is controlled by the cassette control unit 70. An operation unit 172 is also connected to the cassette control unit 70. The operation unit 172 includes a switch (not shown) that is provided on the irradiation surface 12 of the housing 14 and is operated by the photographer when the thickness of the housing 14 is changed.

  Next, the operation of the fifth embodiment will be described. In the electronic cassette 160 according to the fifth embodiment, the housing 14 is in the maximum thickness state shown in FIG. 9A while being stored without being used for imaging, and the radiation detection unit (TFT substrate) 42 and The scintillator 34 is maintained in a separated state. This prevents deformation such as warpage from occurring in the radiation detector (TFT substrate) 42 and the support substrate 36 of the scintillator 34 due to temperature changes. In addition, the administrator of the electronic cassette 160 confirms that the electronic cassette 160 is in a state suitable for storage (a state in which the radiation detection unit (TFT substrate) 42 and the scintillator 34 are separated from each other). It can be easily recognized from the appearance (thickness dimension).

  In the electronic cassette 160, the housing body 16 and the lid body 18 are urged by the compression coil spring 162 in a direction in which the upper surface and the bottom surface of the housing 14 are separated from each other. In addition, while the electronic cassette 160 is stored without being used for photographing, the plug member 168 is positioned at the first position, and the air in the housing 14 is kept sealed in the housing 14. The As a result, while the electronic cassette 160 is stored without being used for photographing, even if an external force is applied to reduce the thickness of the casing 14, the biasing force of the compression coil spring 162 and the casing 14 are sealed. The thickness of the housing 14 is prevented from changing due to the reaction force generated by the air, and the radiation detection unit (TFT substrate) 42 and the scintillator 34 are kept apart.

  When radiographing is performed using the electronic cassette 160, the photographer grips the casing 14 of the electronic cassette 160 and presses the switch of the operation unit 172 as preparation work for radiographic imaging. While turning on, an operation of applying an external force to reduce the thickness of the casing 14 is performed. The cassette control unit 70 energizes the actuator 170 while the switch of the operation unit 172 is on. Thus, while the photographer applies an external force that reduces the thickness of the casing 14, the plug member 168 is positioned at the second position (see FIG. 10B), and the internal space of the casing 14 and the casing 14 are positioned. The thickness of the casing 14 is reduced by the external force applied by the photographer.

  The photographer presses the switch of the operation unit 172 when the casing 14 is in the minimum thickness state shown in FIG. 9B and the radiation detection unit (TFT substrate) 42 and the scintillator 34 are in close contact with each other. The switch is turned off by releasing. The cassette control unit 70 stops energization of the actuator 170 when the switch of the operation unit 172 is turned off. As a result, the plug member 168 is moved to the first position (see FIG. 10A), and communication between the internal space of the housing 14 and the outside of the housing 14 is blocked, so that the air in the housing 14 is blocked. Is sealed in the housing 14. Accordingly, even when an external force is applied to increase the thickness of the casing 14 while the electronic cassette 160 is used for photographing, a reaction force against the external force is generated by the air sealed in the casing 14. As a result, the thickness of the housing 14 is prevented from changing, and the radiation detection unit (TFT substrate) 42 and the scintillator 34 are maintained in close contact with each other.

  When the radiographic image capturing is completed, the photographer turns on the switch by pressing the switch of the operation unit 172. During this time, the cassette control unit 70 energizes the actuator 170, the plug member 168 is positioned at the second position (see FIG. 10B), and the internal space of the housing 14 and the outside of the housing 14 are communicated. As a result, the housing 14 and the lid 18 of the casing 14 of the electronic cassette 160 are relatively displaced in a direction in which the upper surface and the bottom surface of the casing 14 are separated by the urging force of the compression coil spring 162. It returns to the maximum thickness state shown in (A). When the casing 14 returns to the maximum thickness state, the photographer releases the pressing of the switch of the operation unit 172. Thereby, the air in the housing 14 is sealed in the housing 14, and the electronic cassette 160 is in a state suitable for storage (even if an external force is applied to the housing 14, the radiation detection unit (TFT substrate) 42 and the scintillator 34 The state in which the separation is maintained).

  The electronic cassettes 10, 150, 154, 156 described in the first to fourth embodiments are provided with the compression coil spring 162 and the communication switching unit 166 described in the fifth embodiment, The relative displacement of the lid 18 can be realized by either introducing the air pressure generated by the air pressure generator 28 into the housing 14 or applying an external force to the housing 14 by a photographer or the like. Also good.

  In the first, second, fourth, and fifth embodiments, the support substrate 36 on which the scintillator 34 is formed is attached to the upper surface of the top plate of the base 40, while the control substrate 46 is attached to the lower surface of the top plate of the base 40. However, the present invention is not limited to this. For example, the base 40 is omitted, and the support substrate 36 and the control substrate 46 on which the scintillator 34 is formed are connected to the bottom plate 16A of the storage body 16 via a spacer or the like. You may make it attach to. Thereby, the thickness of the casing of the electronic cassette can be further reduced.

  However, in this configuration, since the distance between the scintillator 34 and the control board 46 becomes smaller, the heat radiated from the control board 46 may adversely affect the scintillator 34 (for example, temperature unevenness occurs in the scintillator 34, As a result, the light emission efficiency of the scintillator 34 is uneven). Therefore, between the scintillator 34 and the control board 46, a sheet material having a heat insulating property that blocks heat conduction from the control board 46 to the scintillator 34, or heat radiated from the control board 46 receives heat from the scintillator 34. Sheet material having heat conduction anisotropy that conducts heat in a direction parallel to the heat, or heat for conducting heat radiated from the control board 46 substantially uniformly over the entire heat receiving surface of the scintillator 34. It is preferable to provide a highly conductive sheet material.

10, 150, 154, 156, 160 Electronic cassette 12 Irradiation surface 14 Housing 16 Housing 18 Lid 20 Seal member 26 Valve 28 Air pressure generator 34 Scintillator 38 Shielding member 42 Radiation detection part 58 Light shielding member 70 Cassette control part 152 Light Coupling member 158 Telescopic member 166 Communication switching unit

Claims (12)

A shape having an upper surface and a bottom surface, and an upper surface side member on which the upper surface is formed and a bottom surface side member on which the bottom surface is formed are relatively displaceable so that a distance between the upper surface and the bottom surface changes. And a housing
A light emitting portion disposed in the housing and attached to one of the upper surface side member and the bottom surface side member, which absorbs radiation irradiated to the upper surface or the bottom surface through a subject and emits light;
It is disposed in the casing and is attached to the other of the upper surface side member and the bottom surface side member, detects light emitted from the light emitting portion, and changes in the distance between the upper surface and the bottom surface, A detection unit that switches to a first state in contact with the light emitting unit or a second state that is separated from the light emitting unit;
Including radiation detection panel. The upper surface side member has a shape in which a wall portion is erected along a direction substantially orthogonal to the upper surface member over the entire circumference of an outer edge of the upper surface member whose one surface forms the upper surface.
The bottom surface side member has a shape in which a wall portion is erected along a direction substantially perpendicular to the bottom surface member over the entire circumference of the outer edge of the bottom surface member where one surface forms the bottom surface.
In the housing, the upper surface member and the bottom surface member face each other substantially in parallel, and the wall portion of the upper surface side member and the wall portion of the bottom surface side member extend over the entire circumference. The radiation detection panel according to claim 1, wherein the top surface side member and the bottom surface side member are arranged so as to face each other with a gap along a direction substantially parallel to the bottom surface. The light emitting unit emits radiation irradiated to the first position in the irradiation surface or the first position in the light emission surface at a first position in the radiation irradiation surface or in the light emission surface. A shielding part for shielding the light to be
The detection unit is provided with a light shielding unit that shields light applied to the second position in the light receiving surface at a second position in the light receiving surface having a fixed positional relationship with respect to the first position. The radiation detection panel according to claim 1 or 2. Sealing means for sealing a gap between the upper surface side member and the bottom surface side member;
Communication means for selectively communicating the inside and the outside of the housing;
The radiation detection panel according to any one of claims 1 to 3, further comprising: Sealing means for sealing a gap between the upper surface side member and the bottom surface side member;
A connecting portion for connecting the air pressure generating device such that an internal space of the housing communicates with the air pressure generating device;
Further comprising
Air pressure generated by the air pressure generating device connected to the connection portion is introduced into the internal space via the connection portion, so that the upper surface side member and the bottom surface side member are relatively displaced. The radiation detection panel of any one of Claims 1-4.   The radiation detection panel according to claim 1, further comprising an urging unit that urges the upper surface side member and the bottom surface side member in a direction in which a distance between the upper surface and the bottom surface is increased. .   When the top surface side member and the bottom surface side member are relatively displaced in a direction in which at least the distance between the top surface and the bottom surface is increased, the relative position between the top surface side member and the bottom surface side member is The radiation detection panel according to any one of claims 1 to 6, further comprising holding means for holding at a relative position after being relatively displaced. Sealing means for sealing a gap between the upper surface side member and the bottom surface side member;
Communication means for selectively communicating the inside and the outside of the housing;
Further comprising
While the upper surface side member and the bottom surface side member are relatively displaced, the holding means allows the inside and the outside of the housing to communicate with each other by the communication means, and the upper surface side member and the bottom surface side member And the relative position of the upper surface side member and the lower surface side member is relatively displaced by blocking communication between the inside and the outside of the housing by the communication means. The radiation detection panel according to claim 7, wherein the radiation detection panel is held at a relative position after the operation.   The gap is provided between the upper surface side member and the bottom surface side member, seals the gap between the upper surface side member and the bottom surface side member, and is accompanied by relative displacement between the upper surface side member and the bottom surface side member. The radiation detection panel according to claim 1, further comprising an expansion / contraction member that expands and contracts in accordance with a change in the size of the radiation detection panel.   An optical coupling member that optically couples the light emission unit and the detection unit is provided between the light emission unit and the detection unit. In the first state, the detection unit is the light The radiation detection panel according to claim 1, wherein the radiation detection panel is in contact with the light emitting portion via a coupling member.   The thickness of the casing in the first state where the detection unit is in contact with the light emitting unit is the same size as the thickness of the casing in a cassette configured to record the irradiated radiation as an image on a photosensitive material. The radiation detection panel according to any one of claims 1 to 10.   The radiation detection panel according to claim 1, wherein the detection unit is disposed upstream of the light emitting unit in the direction of arrival of radiation.

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