JP2011137804A - Radiation imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly-convenient radiation imaging device using a radiation detection panel. <P>SOLUTION: In an electronic cassette 10, a panel unit 14 and a panel unit 16 are connected together through a hinge 62, and in the close state wherein the panel units 14, 16 are piled up, a second surface 74 of a radiation detection panel 20B of the panel unit 16 is faced to a first surface 72 of a radiation detection panel 20A of the panel unit 14. In the electronic cassette, a filter 78 for energy conversion is arranged between the panel units 14, 16 in the closed state, and by irradiating an imaging surface 82C with a radiation, each first surface of the radiation detection panels 20A, 20B is irradiated with a radiation having a different energy component. Hereby, radiation image data having a different energy component used for energy subtraction with an equivalent image quality are acquired by a radiation with which the same surface of the radiation detection panels is irradiated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiation imaging apparatus, and more particularly to a radiation imaging apparatus provided with a radiation detection panel.

  In recent years, a radiation sensitive layer is arranged on a TFT (Thin Film Transistor) active matrix substrate, radiation such as irradiated X-rays is detected, and directly converted into radiation image data representing the distribution of radiation dose and output. FDP (Flat Panel Detector) has been put into practical use. A radiation imaging apparatus (hereinafter also referred to as an electronic cassette) that incorporates a panel-type radiation detector such as an FDP, a control unit including an image memory, and a power supply unit, and stores radiation image data output from the radiation detector in the image memory. Is also put into practical use.

  For example, with an electronic cassette, the subject can be photographed while being placed on a stretcher or bed, and the position of the electronic cassette relative to the subject can be changed, which makes it easy to adjust the imaging region. Even when a subject is photographed, it can be flexibly dealt with.

  In relation to such an electronic cassette, for example, in Patent Document 1, two flat sensors in which photoelectric conversion elements are arranged in a matrix shape can be opened and closed by connecting them on one side, thereby providing a flat sensor. It is proposed to ensure the area of the product and to ensure storage and portability. Japanese Patent Application Laid-Open No. 2004-228561 proposes to reduce the weight by allowing the cassette having the radiation detector and the control unit for controlling the radiation detector to be detachable.

  On the other hand, there is an energy subtraction method that emphasizes a specific structure of a subject by using a high-energy component radiation image and a low-energy component radiation image for the same subject. In this technology, in Patent Document 3 and Patent Document 4, a radiation image can be acquired between two detectors or by stimulating light emission using a filter (such as a radiation energy separation filter) containing a low-energy component absorbing material for radiation. The structure which arrange | positions a pertinent filter between the two storage fluorescent substance sheet | seats to perform 1 shot energy subtraction is proposed.

JP 2003-339687 A JP 2009-80103 A JP 2001-299733 A JP 2004-264547 A

  On the other hand, in a panel-shaped radiation detection panel using FPD or the like, a photoelectric conversion layer that performs radiation-charge conversion or radiation-light-charge conversion on one surface of a TFT active matrix substrate (hereinafter also referred to as a TFT substrate). The radiation conversion layer is provided to collect charges generated in the radiation conversion layer. In such a radiation detection panel, a radiation image by radiation irradiated from the radiation conversion layer side is usually obtained, but even when radiation is irradiated from the TFT substrate side, the irradiated radiation image is not displayed. can get.

  It is an object of the present invention to provide a highly convenient radiation imaging apparatus that uses such a radiation detection panel and can handle various types of radiation images.

  The present invention according to claim 1, which achieves the above object, includes a first panel unit in which one surface of a radiation detection panel is directed to one surface and the radiation detection panel is accommodated, and radiation detection is performed on one surface. The second panel unit in which the other surface of the panel is directed to accommodate the radiation detection panel, one end of the first panel unit, and one end of the second panel unit are connected to the first panel unit. A closed state in which one surface of the panel unit and one surface of the second panel unit face each other, and one surface of the first panel unit and one surface of the second panel unit are in the same direction A coupling means for pivotally connecting the two panels in an open state directed to the radiation detection panel, the radiation detection panel of the first panel unit in the closed state, and the radiation detection of the second panel unit. It is disposed between the panel, including a filter member that absorbs a predetermined energy component from the radiation incident.

  According to this invention, the 1st panel unit and the 2nd panel unit are connected by the connection means so that a closed state and an open state can be taken. In addition, the first and second panel units are provided with radiation detection panels, and radiation image data corresponding to the irradiated radiation is obtained by irradiating the radiation in the overlapped closed state and the expanded open state. can get.

  A filter member is provided between the radiation detection panel of the first panel unit and the radiation detection panel of the second panel unit in the closed state, and one radiation detection is performed by irradiating the radiation. Radiation image data of a high energy component is obtained from the panel, and radiation image data of a low energy component is obtained from the other radiation detection panel. At this time, the radiation is applied to the same surface (one surface) of the radiation detection panel of the first panel unit and the radiation detection panel of the second panel unit.

  In the present invention, the filter member can be arranged between the first panel and the second panel. At this time, the filter member is connected to the connecting means. It is possible to take a configuration in which the first panel unit and the second panel unit are connected to each other so as to be rotatable. Moreover, in this invention, the said filter member can take the structure accommodated in a said 2nd panel unit.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the control unit configured by the control unit and the power source unit is accommodated in the first panel unit in the first panel unit. The radiation detection panel is housed in a position on the other surface side of the radiation detection panel, and radiation image data based on radiation irradiated from the second panel unit side is obtained.

  According to a sixth aspect of the present invention, there is provided the flat radiation according to the fifth aspect of the present invention, which is provided between the radiation detection panel and the control unit in the first panel unit and prevents back scattering during imaging. Including an absorbent member.

  According to the present invention, back scattering is prevented from occurring due to the control unit provided in the first panel unit, and high-quality radiation image data is obtained.

  The invention according to claim 7 is the invention according to claim 5 or claim 6, wherein a flat grid provided on the other surface of the second panel unit for removing scattered rays due to an imaging target during imaging is provided. Is provided.

  According to this invention, since radiation is irradiated to the two radiation detection panels via the grid, the radiation scattering caused by the imaging target is removed, and a high-quality radiation image is obtained.

  According to an eighth aspect of the present invention, in any one of the fifth to seventh aspects of the present invention, the invention includes a heat radiating unit that is formed on the other surface of the first panel unit and that releases heat generated by the control unit.

  According to this invention, for example, the heat radiating means is formed by unevenness, fins, etc. formed on the surface of the first panel unit. As a result, it is possible to prevent image quality degradation and radiation detection panel degradation caused by the invention of the control unit.

  The invention according to claim 9 is the invention according to claim 1 or 2, wherein the invention is provided on a peripheral portion of at least one of the one surface of the first panel unit and the one surface of the second panel unit, A projecting member that forms a gap in which the filter member is disposed between the first panel unit and the second panel unit in the closed state;

  According to the present invention, the projecting member is provided on at least one peripheral portion of the mutually opposing surfaces of the first and second panel units, and thereby a space in which the filter member is disposed is accurately ensured. .

  According to a tenth aspect of the present invention, in the invention according to any one of the first to ninth aspects, the radiation detection panel converts the radiation into light by a scintillator that converts the radiation into light, and a radiation image represented by the light is obtained. The scintillator may be configured to include a columnar crystal of a phosphor material.

  According to an eleventh aspect of the present invention, in the invention of the tenth aspect, the phosphor material is preferably CsI.

  According to a twelfth aspect of the present invention, in the invention of the tenth or eleventh aspect, the radiation detection panel is a sensor unit that generates charges by receiving light converted by the scintillator on an insulating substrate, And a thin film transistor for reading out the electric charge generated in the sensor unit, the sensor unit includes an organic photoelectric conversion material, and the active layer of the thin film transistor includes an amorphous oxide or an organic semiconductor material or The substrate may include carbon nanotubes, and the substrate may be formed of plastic.

  According to a thirteenth aspect of the invention, in any one of the first to twelfth aspects of the invention, the connecting means may detachably connect the first panel unit and the second panel unit.

  As described above, according to the first aspect of the invention, the one surface of the radiation detection panel in the first panel unit is opposed to the other surface of the radiation detection panel in the second panel unit. Radiation image data for energy subtraction with matching image characteristics and equivalent image quality can be obtained.

  In the invention according to claim 5, since the control unit is provided in the first panel unit, radiation image data for energy subtraction can be obtained even when the control unit is provided integrally. In the invention according to, image quality deterioration caused by the control unit does not occur at this time.

  According to the invention of claim 7, since the grid is provided, radiation image data for forming a high-quality image can be obtained from each of the two radiation detection panels.

  In addition, according to the invention of claim 8, it is possible to prevent deterioration in image quality and deterioration of the radiation detection panel caused by heat generated from the control unit.

It is a perspective view showing a schematic structure of an electronic cassette concerning a 1st embodiment. (A) is a perspective view which shows the closed state of the electronic cassette of FIG. 1, (B) is a perspective view which shows the open state of the electronic cassette of FIG. It is the schematic block diagram which looked at the electronic cassette from the direction which cross | intersects the irradiation direction of a radiation. It is the schematic which showed the layer structure of the radiation detection panel typically. It is sectional drawing which showed roughly the structure of the switch element of the radiation detector which concerns on embodiment. It is the schematic which showed typically the structure when the radiation detection panel was planarly viewed. It is a schematic block diagram of a control unit. It is a cross-sectional side view for demonstrating the surface reading system and back surface reading system of the radiation to a radiation detector. It is a perspective view which shows another schematic structure of the electronic cassette concerning 1st Embodiment. (A) is a perspective view which shows the closed state of the electronic cassette of FIG. 9, (B) is a perspective view which shows the open state of the electronic cassette of FIG. It is a perspective view which shows another schematic structure of the electronic cassette concerning 1st Embodiment. (A) is a perspective view which shows the closed state of the electronic cassette of FIG. 11, (B) is a perspective view which shows the open state of the electronic cassette of FIG. It is sectional drawing of an example of a structure at the time of arrange | positioning a radiation detection panel by a surface reading system. It is the schematic block diagram seen from the direction which cross | intersects the irradiation direction of the radiation which shows the closed state of the electronic cassette concerning 2nd Embodiment. It is a schematic block diagram which shows another example of the layer structure of a radiation detection panel. It is a perspective view which shows schematic structure of the electronic cassette concerning 3rd Embodiment. (A) And (B) is the schematic block diagram which looked at the electronic cassette from the direction which cross | intersects the irradiation direction of a radiation. It is a perspective view which shows schematic structure of the electronic cassette concerning 4th Embodiment. (A) And (B) is the schematic block diagram which looked at the electronic cassette from the direction which cross | intersects the irradiation direction of a radiation. (A) And (B) is a schematic block diagram of the electronic cassette concerning a 5th embodiment, (A) shows a closed state and (B) shows an open state. It is a schematic block diagram which shows the closed state of the electronic cassette concerning 6th Embodiment. It is a perspective view which shows schematic structure of the electronic cassette made detachable with a panel unit. It is a perspective view which shows another schematic structure of the electronic cassette which concerns on another form. It is a perspective view which shows the closed state of the electronic cassette of FIG.

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
1 to 3 show an electronic cassette 10 according to the present exemplary embodiment. The electronic cassette 10 includes housings 12A and 12B. The casings 12A and 12B are formed in a flat plate shape (thin box shape) whose thickness direction (the vertical direction in FIG. 2 and FIG. 3) is short. The housing 12A is provided with a radiation detection panel 20 to form a panel unit 14, and the housing 12B is provided with a radiation detection panel 20 to form a panel unit 16 (hereinafter referred to as a housing). 12A and 12B are also referred to as panel units 14 and 16). In the electronic cassette 10, the radiation detection panel 20 having the same configuration is used. However, when making a distinction, the panel unit 14 side is the radiation detection panel 20A, and the panel unit 16 side is the radiation detection panel 20B.

  As shown in FIG. 3, a hinge 62 is provided between the panel units 14 and 16 as an example of a connecting means. The hinge 62 connects one side of the panel unit 14 and one side of the panel unit 16 corresponding to one side of the panel unit 14. Further, in the electronic cassette 10, the panel unit 14 and the panel unit 16 are in a closed state in which one surface of the panel unit 16 is opposed to one surface of the panel unit 14 with the pin 62A of the hinge 62 as an axis. It is possible to rotate between the open states in which the faces opposed at the time are oriented in the same direction on the same plane.

  The electronic cassette 10 can be held in a closed state of the panel units 14 and 16 by a lock mechanism (not shown). Further, in the electronic cassette 10, the panel units 14 and 16 can be relatively rotated about the pin 62 </ b> A of the hinge 62 by releasing the lock mechanism. Furthermore, in this Embodiment, although the one side (short side) along the longitudinal direction of the panel units 14 and 16 is connected, the structure which connects not only this but a long side may be sufficient. Furthermore, in the following description, the panel units 14 and 16 are described so that the surfaces of the panel units 16 facing in the same direction as the panel units 14 are in the same direction. However, the present invention is not limited thereto, and at least in the same direction. Any configuration is suitable.

  Here, the radiation detection panel 20 (20A, 20B) built in each of the panel units 14 and 16 will be described. The radiation detection panel 20 detects the irradiated radiation and outputs an electrical signal (radiation detection signal) corresponding to the distribution of the radiation dose. As shown in FIG. 4, the radiation detection panel 20 includes a substrate (hereinafter referred to as a TFT substrate 26) in which a switching element 24 such as a thin film transistor (TFT) is formed on an insulating substrate 22. Yes. For example, a glass substrate, various ceramic substrates, and a resin substrate can be used as the insulating substrate 22, but the insulating substrate 22 is not limited to these materials.

On the TFT substrate 26, a scintillator layer 28 that converts incident radiation into light is formed as an example of a radiation conversion layer that converts incident radiation. As the scintillator layer 28, for example, CsI: Tl, GOS (Gd ₂ O ₂ S: Tb) can be used, but it is not limited to these materials.

  The wavelength range of light emitted by the scintillator layer 28 is preferably a visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by the radiation detection panel 20, a green wavelength range is included. It is more preferable.

  Specifically, the phosphor used in the scintillator layer 28 preferably contains cesium iodide (CsI) when imaging using X-rays as radiation, and the emission spectrum upon irradiation with X-rays is 420 nm to 600 nm. It is particularly preferred to use some CsI (Tl). Note that the emission peak wavelength of CsI (Tl) in the visible light region is 565 nm.

  The scintillator layer 28 may be formed by vapor deposition on a vapor deposition substrate, for example, when it is intended to be formed of columnar crystals such as CsI (Tl). Thus, when the scintillator layer 28 is formed by vapor deposition, an Al plate is often used as the vapor deposition substrate from the viewpoint of X-ray transmittance and cost, but is not limited thereto. When GOS is used as the scintillator layer 28, the scintillator layer 28 may be formed by applying GOS to the surface of the TFT substrate 26 without using a vapor deposition substrate.

  Between the TFT substrate 26 and the scintillator layer 28, a photoconductive layer 30 that generates charges when light converted by the scintillator layer 28 is incident is disposed. A bias electrode 32 for applying a bias voltage to the photoconductive layer 30 is formed on the surface of the photoconductive layer 30 on the scintillator layer 28 side.

  A flattening layer 38 for flattening the TFT substrate 26 is formed on the TFT substrate 26. An adhesive layer 39 for bonding the scintillator layer 28 to the TFT substrate 26 is formed between the TFT substrate 26 and the scintillator layer 28 and on the planarizing layer 38.

  The photoconductive layer 30 absorbs light emitted from the scintillator layer 28 and generates a charge corresponding to the absorbed light. The photoconductive layer 30 may be formed of a material that generates charges when irradiated with light. For example, the photoconductive layer 30 may be formed of amorphous silicon, an organic photoelectric conversion material, or the like. The photoconductive layer 30 containing amorphous silicon has a wide absorption spectrum and can absorb light emitted by the scintillator layer 28. If the photoconductive layer 30 includes an organic photoelectric conversion material, it has a sharp absorption spectrum in the visible region, and electromagnetic waves other than light emitted by the scintillator layer 28 are hardly absorbed by the photoconductive layer 30, such as X-rays. Noise generated when radiation is absorbed by the photoconductive layer 30 can be effectively suppressed.

  The organic photoelectric conversion material constituting the photoconductive layer 30 is preferably such that its absorption peak wavelength is closer to the emission peak wavelength of the scintillator layer 28 in order to absorb light emitted by the scintillator layer 28 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator layer 28, but if the difference between the two is small, the light emitted from the scintillator layer 28 can be sufficiently absorbed. It is. Specifically, the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength with respect to the radiation of the scintillator layer 28 is preferably within 10 nm, and more preferably within 5 nm.

  Examples of organic photoelectric conversion materials that can satisfy such conditions include quinacridone-based organic compounds and phthalocyanine-based organic compounds. For example, since the absorption peak wavelength of quinacridone in the visible region is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI (Tl) is used as the material of the scintillator layer 28, the difference in the peak wavelength may be within 5 nm. The amount of charge generated in the photoconductive layer 30 can be substantially maximized.

On the TFT substrate 26, a charge collecting electrode 34 for collecting charges generated in the photoconductive layer 30 is formed. The TFT substrate 26 reads the charges collected by the charge collection electrodes 34 by turning on the switching elements 24 provided corresponding to the charge collection electrodes 34, respectively.

  Next, the photoconductive layer 30 applicable to the radiation detection panel 20 according to the present embodiment will be specifically described.

  The electromagnetic wave absorption / photoelectric conversion site in the radiation detection panel 20 according to the present invention includes a pair of charge collection electrodes 34 and a bias electrode 32 and an organic photoconductive layer 30 sandwiched between the charge collection electrodes 34 and the bias electrode 32. It can be comprised by the organic layer to contain. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact improvement. It can be formed by stacking or mixing parts.

  The organic layer preferably contains an organic p-type compound or an organic n-type compound.

  The organic p-type semiconductor (compound) is a donor organic semiconductor (compound) mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound.

  An organic n-type semiconductor (compound) is an acceptor organic semiconductor (compound) mainly represented by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound.

  Since the materials applicable as the organic p-type semiconductor and organic n-type semiconductor and the configuration of the photoconductive layer 30 are described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted. The photoconductive layer 30 may be formed by further containing fullerenes or carbon nanotubes.

  The sensor unit 35 constituting each pixel unit may include at least the charge collection electrode 34, the photoconductive layer 30, and the bias electrode 32. In order to suppress an increase in dark current, an electron blocking film and a hole blocking unit are included. It is preferable to provide at least one of the films, and it is more preferable to provide both.

  The electron blocking film can be provided between the charge collection electrode 34 and the photoconductive layer 30, and when a bias voltage is applied between the charge collection electrode 34 and the bias electrode 32, the charge collection electrode 34 to the photoconductive layer 30. It is possible to prevent the dark current from being increased due to the injection of electrons.

  An electron donating organic material can be used for the electron blocking film.

  The material actually used for the electron blocking film may be selected according to the material of the adjacent electrode, the material of the adjacent photoconductive layer 30 and the like, and the electron function is 1.3 eV or more from the work function (Wf) of the adjacent electrode material. Those having a large affinity (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoconductive layer 30 are preferable. Since the material applicable as the electron donating organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  The thickness of the electron blocking film is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably 50 nm, in order to surely exhibit the dark current suppressing effect and prevent a decrease in the photoelectric conversion efficiency of the sensor unit 35. It is 100 nm or less.

  The hole blocking film can be provided between the photoconductive layer 30 and the bias electrode 32. When a bias voltage is applied between the charge collecting electrode 34 and the bias electrode 32, the hole blocking film is applied from the bias electrode 32 to the photoconductive layer 30. It is possible to suppress the increase in dark current due to the injection of holes.

  An electron-accepting organic material can be used for the hole blocking film.

  The thickness of the hole blocking film is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to reliably exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the sensor unit 35. It is 50 nm or more and 100 nm or less.

  The material actually used for the hole blocking film may be selected according to the material of the adjacent electrode, the material of the adjacent photoconductive layer 30 and the like, and 1.3 eV or more from the work function (Wf) of the material of the adjacent electrode. A material having a large ionization potential (Ip) and an Ea equivalent to or larger than the electron affinity (Ea) of the material of the adjacent photoconductive layer 30 is preferable. Since the material applicable as the electron-accepting organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  In the case where the bias voltage is set so that the holes move to the bias electrode 32 and the electrons move to the charge collecting electrode 34 among the charges generated in the photoconductive layer 30, the electron blocking film and the hole blocking are set. What is necessary is just to reverse the position of a film | membrane. Moreover, it is not necessary to provide both the electron blocking film and the hole blocking film. If either one is provided, a certain degree of dark current suppressing effect can be obtained.

  FIG. 5 schematically shows the configuration of the switching element 24.

  Corresponding to the charge collection electrode 34, a switching element 24 is formed that converts the electric charge transferred to the charge collection electrode 34 into an electric signal and outputs the electric signal. The region where the switching element 24 is formed has a portion that overlaps the charge collection electrode 34 in plan view. With such a configuration, the switching element 24 and the sensor unit 35 in each pixel portion have a thickness. There will be overlap in the direction. In order to minimize the plane area of the radiation detection panel 20 (pixel unit), it is desirable that the region where the switching element 24 is formed is completely covered by the charge collection electrode 34.

  In the switching element 24, a gate electrode 220, a gate insulating film 222, and an active layer (channel layer) 224 are stacked, and a source electrode 226 and a drain electrode 228 are formed on the active layer 224 at a predetermined interval. Yes.

  The drain electrode 228 is electrically connected to the corresponding charge collection electrode 34 through a wiring made of a conductive material formed through an insulating film 219 provided between the insulating substrate 22 and the charge collection electrode 34. Has been. Thereby, the charges collected by the charge collection electrode 34 can be moved to the switching element 24.

  The active layer 224 can be formed of, for example, amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, or the like. Note that the material forming the active layer 224 is not limited thereto.

The amorphous oxide that can form the active layer 224 is preferably an oxide containing at least one of In, Ga, and Zn (for example, In—O-based), and at least two of In, Ga, and Zn. Oxides containing one (for example, In—Zn—O, In—Ga—O, 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. Note that the amorphous oxide that can form the active layer 224 is not limited thereto.

  Examples of the organic semiconductor material that can form the active layer 224 include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. In addition, about the structure of a phthalocyanine compound, since it is demonstrated in detail in Unexamined-Japanese-Patent No. 2009-212389, description is abbreviate | omitted.

  If the active layer 224 of the switching element 24 is formed of an amorphous oxide, an organic semiconductor material, or a carbon nanotube, the radiation such as X-rays is not absorbed, or even if it is absorbed, a very small amount remains. Generation of noise in the element 24 can be effectively suppressed.

  Further, when the active layer 224 is formed of carbon nanotubes, the switching speed of the switching element 24 can be increased, and the switching element 24 having a low degree of light absorption in the visible light region can be formed. When the active layer 224 is formed of carbon nanotubes, the performance of the switching element 24 is remarkably deteriorated only by mixing a very small amount of metallic impurities into the active layer 224. Therefore, the carbon nanotubes of extremely high purity can be obtained by centrifugation or the like. Need to be separated and extracted.

  Here, any of the above-described amorphous oxide, organic semiconductor material, carbon nanotube, and organic photoelectric conversion material can be formed at a low temperature. Therefore, the insulating substrate 22 is not limited to a highly heat-resistant substrate such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate such as plastic, 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. If such a plastic flexible substrate is used, it is possible to reduce the weight, which is advantageous for carrying around, for example. In particular, the electronic cassette 10 according to the present exemplary embodiment incorporates two radiation detection panels 20. For this reason, each photoconductive layer 30 of the radiation detection panel 20 includes an organic photoelectric conversion material, and each active layer 224 of each switching element 24 includes an amorphous oxide, an organic semiconductor material, or a carbon nanotube. Thus, by using plastic for the insulating substrate 22, the electronic cassette 10 can be significantly reduced in weight.

  Further, the substrate 22 is provided with 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.

  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 also be used for 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, warping after production is small and it is difficult to crack. In addition, aramid can form a substrate thinner than a glass substrate or the like. The insulating substrate 22 may be formed by laminating an ultrathin glass substrate and aramid.

  Bionanofiber is a composite of cellulose microfibril bundles (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. A thin insulating substrate 22 can be formed.

  In the present embodiment, the switching element 24, the sensor unit 35, and the transparent planarization layer 38 are sequentially formed on the insulating substrate 22, and an adhesive resin having a low light absorption property or the like is used on the insulating substrate 22. The radiation detection panel 20 is formed by attaching the scintillator layer 28 with the adhesive layer 39. Hereinafter, the insulating substrate 22 formed up to the transparent insulating film 206 is referred to as a TFT substrate 26.

  As shown in FIG. 6, the sensor unit 35 and the switching element 24 are two-dimensionally arranged on the TFT substrate 26. On the TFT substrate 26, a plurality of gate wirings 40 for turning on / off each switching element 24 extended in a certain direction (row direction), and a direction intersecting with the gate wirings 40 (column direction) are extended. A plurality of data wirings 42 for reading out charges through the switching element 24 in the on state are provided. The TFT substrate 26 has, for example, a rectangular shape having four sides at the outer edge in plan view, and individual gate wirings 40 and individual data wirings 42 are connected to one side of the peripheral portion of the TFT substrate 26 in plan view. The connection terminals 43 are arranged.

  As shown in FIG. 3, in the electronic cassette 10, the panel unit 14 is provided with a control unit 18 that performs control such as imaging of radiation images using the radiation detection panels 20 </ b> A and 20 </ b> B. As shown in FIG. 7, the connection terminals 43 of the radiation detection panels 20 (20 </ b> A, 20 </ b> B) provided in each of the panel units 14, 16 are control units provided in the control unit 18 via connection wires 44. 50. In FIG. 7, the radiation detection panels 20 </ b> A and 20 </ b> B are schematically arranged to be shifted, the connection terminals 43 are provided on one side, and the connection wiring 44 is drawn out. Further, the panel unit 14 and the panel unit 16 can take any known connection form such as a connection using a flexible cable as the connection wiring 44.

  The control unit 50 drives the radiation detection panels 20A and 20B and converts radiation detection signals output from the radiation detection panels 20A and 20B into radiation image data. Further, the control unit 18 is provided with a power supply unit 70 that supplies power to the control unit 50 and the like.

  The control unit 50 includes a gate wiring driver 52, a signal processing unit 54, an image memory 56, a cassette control unit 58, and a wireless communication unit 60. Each switching element 24 (not shown in FIG. 7, not shown in FIGS. 4 and 6) of the radiation detection panels 20A and 20B is sequentially turned on in units of rows by a signal supplied from the gate wiring driver 52 through the gate wiring 40. Then, the electric charges read by the switching element 24 turned on are transmitted through the data wiring 44 as an electric signal and input to the signal processing unit 54. Thereby, the electric charges are sequentially read out in units of rows, and a radiation detection signal representing a two-dimensional radiation image is acquired.

  Although not shown, the signal processing unit 54 is provided with an amplification circuit and a sample hold circuit for amplifying an input electric signal for each data wiring 42. The electric signals transmitted through the individual data wirings 42 and input are amplified by the amplifier circuit and then held by the sample and hold circuit. Further, a multiplexer and an A / D (analog / digital) converter (both not shown) are sequentially connected to the output side of the sample hold circuit, and the electric signals held in the individual sample hold circuits are the multiplexers. Are sequentially input (serially) and converted into digital image data (radiation image data) by an A / D converter.

  The signal processing unit 54 is connected to the image memory 56, and image data output from the A / D converter of the signal processing unit 54 is used as radiation image data captured using the radiation detection panel 20 as an image memory. 56 are sequentially stored. The image memory 56 has a storage capacity capable of storing a plurality of pieces of radiation image data (for a plurality of images), and each time a radiation image is captured, the radiation image data obtained by the imaging is The images are sequentially stored in the image memory 56. The gate wiring driver 52 and the signal processing unit 54 can operate the radiation detection panels 20A and 20B separately. Thereby, in the electronic cassette 10, the radiographic image data obtained simultaneously from the two radiation detection panels 20 can be processed as one continuous radiographic image data, and can also be processed as separate radiographic image data.

  A gate wiring driver 52, a signal processing unit 54, and an image memory 56 are connected to the cassette control unit 58. The cassette control unit 58 includes a microcomputer, and includes a CPU 58A, a memory 58B including a ROM and a RAM, a non-volatile storage unit 58C including a flash memory and the like, and controls the entire operation of the electronic cassette 10.

  In addition, a wireless communication unit 60 is connected to the cassette control unit 58. The wireless communication unit 60 corresponds to a wireless local area network (LAN) standard represented by IEEE (Institute of Electrical and Electronics Engineers) 802.11a / b / g / n, for example, and is an external device by wireless communication. Controls the transmission of various information to and from.

  The wireless communication unit 60 transmits various kinds of information bidirectionally by infrared communication, for example. In this case, as shown in FIGS. 1 to 3, in the electronic cassette 10, for example, a light transmitting / receiving unit 64 is provided on the side surface of the housing 12. This prevents the transmission / reception unit 64 from being in the shadow of the subject and preventing the transmission of information, regardless of whether the panel units 14 and 16 are closed or the panel units 14 and 16 are open. Can be prevented. In the electronic cassette 10, the light transmitting / receiving unit 64 is provided in the housing 12 </ b> A of the panel unit 14.

  The cassette control unit 58 is an external device that controls or manages radiation imaging via the wireless communication unit 60 (for example, a console that controls the operation of a device such as a radiation generator or a server connected to a hospital network) ) And wireless communication. Here, as an example, it is assumed that various types of information are transmitted to and received from the console. In the present embodiment, the wireless communication unit 60 will be described as an example. However, instead of this, a wired communication unit that performs communication by wired connection may be applied. Standards may be applied.

  The cassette control unit 58 stores various types of information such as imaging condition information received from the console via the wireless communication unit 60 and patient information regarding the patient who is the subject, and each radiation detection panel is based on the imaging condition information. 20 operation control and charge readout control from each radiation detection panel 20 are performed.

  As shown in FIG. 2A, the electronic cassette 10 can be provided with a display portion 66. For example, a liquid crystal panel (LCD: Liquid Crystal Display) is used as the display unit 66 so that radiation can be transmitted. The display unit 66 is provided on the surface of the panel unit 16 opposite to the panel unit 14.

  As shown in FIG. 7, the display unit 66 is connected to the cassette control unit 58, and the display is controlled by the cassette control unit 58. The cassette control unit 58 displays information set to be useful at the time of imaging from imaging condition information, patient information, and the like input from the console via the wireless communication unit 60. As such information, for example, information such as a name and ID for identifying a subject (patient) can be applied, so that an operator such as a radiographer can It is possible to confirm whether or not the person is the person, and it is possible to prevent the subject who performs the photographing from being mixed up.

  Further, the information displayed on the display unit 66 may include an imaging region and imaging conditions, thereby preventing the imaging region from being misaligned or being imaged under wrong imaging conditions. . For example, as a method for specifying the imaging region, the corresponding region may be displayed by characters or the like, or a sample image of the imaging region may be displayed. Furthermore, imaging guidance such as imaging procedures for the subject may be displayed on the display unit 66. Thereby, since the radiographer can perform radiographing while confirming the operation of the subject at a location away from the subject, the amount of radiation received by the radiographer can be suppressed.

  The power supply unit 70 supplies power to the various circuits and elements described above (a microcomputer functioning as the gate line driver 52, the signal processing unit 54, the image memory 56, the wireless communication unit 60, and the cassette control unit 58). In FIG. 7, illustration of wirings connecting the power supply unit 70 with various circuits and elements is omitted. The power supply unit 70 may incorporate a battery (secondary battery), and this battery may be used as a power source.

  Incidentally, as shown in FIG. 4, in the radiation detection panel 20, the TFT substrate 26, the planarization layer 38, and the adhesive layer 39 are formed of a material that transmits radiation. The radiation applied to the imaging using the radiation detection panel 20 includes radiation having a high energy component (for example, energy of 50 keV or more) and low energy component (for example, energy of 40 keV or less). In the radiation detection panel 20, both high-energy component and low-energy component radiation pass, but the low-energy component radiation transmittance is lower than the high-energy component radiation transmittance.

  In the following, the surface (normal surface) on the scintillator layer 28 side of the radiation detection panel 20 is referred to as a first surface 72, and the surface (normal back surface) on the opposite side (TFT substrate 26 side) from the scintillator layer 28 is second. The surface 74 will be described.

  In the radiation detection panel 20, when radiation is irradiated from the scintillator layer 28 side (first surface 72 side), radiation is converted into light at a portion away from the photoconductive layer 30 along the thickness direction of the scintillator layer 28. Is done. In the radiation detection panel 20, when radiation is irradiated from the TFT substrate 26 side (second surface 74 side), conversion from radiation to light is performed in a portion near the photoconductive layer 30 in the thickness direction of the scintillator layer 28. Done.

  Therefore, in the radiation detection panel 20, between the radiation image data obtained when radiation is irradiated from the first surface 72 side and the radiation image data obtained when radiation is irradiated from the second surface 74 side. There is a difference between the obtained images.

  Here, as shown in FIG. 3, the radiation detection panel 20 </ b> A is arranged in the panel unit 14 closer to the panel unit 16 than the control unit 18. In the panel unit 14, a radiation absorbing plate 80 is disposed between the control unit 18 and the radiation detection panel 20A. The radiation absorbing plate 80 is formed of, for example, lead (lead plate) or the like, and absorbs radiation that has passed through the radiation detection panel 20A.

  In the electronic cassette 10, the radiation detection panel 20 </ b> A provided in the panel unit 14 is directed so that the first surface 72 side is directed upward (the upper side in FIG. 1 to FIG. 3), and the second surface 74 side is the control unit 18 side (FIG. 1 to 3 in FIG. In the electronic cassette 10, the second surface 74 side of the radiation detection panel 20 </ b> B of the panel unit 16 is disposed so as to face the panel unit 14 side in the closed state.

  In the electronic cassette 10, radiation image data corresponding to the radiation irradiated on the surface of the panel unit 14 on the panel unit 16 side (hereinafter also referred to as an imaging surface 82A) is obtained from the radiation detection panel 20A. In the electronic cassette 10, when the panel units 14 and 16 are closed, radiation is irradiated from the surface of the panel unit 16 on which the display unit 66 is provided (hereinafter also referred to as an imaging surface 82C). In addition, radiation image data corresponding to the irradiated radiation is obtained from the radiation detection panel 20B.

  Further, in the electronic cassette 10, radiation image data can be obtained even when radiation is irradiated from the second surface 74 side as the radiation detection panel 20, from which the panel units 14 and 16 are opened. Radiation image data can also be obtained by radiation irradiated on the upper surface of the panel unit 16 (hereinafter also referred to as the imaging surface 82B).

  Therefore, in the electronic cassette 10, radiation image data corresponding to the radiation applied to the imaging surface 82A of the panel unit 14 when the panel units 14 and 16 shown in FIG. Radiation image data corresponding to the radiation irradiated to the imaging surface 82C when the panel units 14 and 16 shown in A) are closed is obtained, and further, when the panel units 14 and 16 are open, the imaging surface of the panel unit 16 is obtained. Radiation image data corresponding to the radiation irradiated to 82B can also be obtained. 2A and 2B, the irradiation direction of radiation is indicated by an arrow A.

  On the other hand, as shown in FIG. 1, the panel unit 14 is formed with protruding members 76 having a predetermined height on the surface facing the panel unit 16 and at the four corners in plan view. Thereby, in the electronic cassette 10, when the panel unit 14 and the panel unit 16 are overlapped (closed state), a predetermined gap is generated between the panel unit 14 and the panel unit 16. In the electronic cassette 10, the casings 12 </ b> A and 12 </ b> B are coupled to the hinge 62 in accordance with the gap.

  As shown in FIGS. 1 to 3, in the electronic cassette 10, an energy conversion filter 78, which is an example of a filter member, is disposed on the panel unit 16. The energy conversion filter 78 is attached to the panel unit 14 side surface (imaging surface 82 </ b> B) of the panel unit 16 so as to be between the panel unit 14 and the panel unit 16 when the panel units 14 and 16 are closed. ing. The energy conversion filter 78 may be detachably attached to the imaging surface 82B of the panel unit 16, and when the panel units 14 and 16 are overlapped, the energy conversion filter 78 is It may be inserted between the panel units 14 and 16.

  The energy conversion filter 78 is configured to absorb, for example, the energy of radiation in a predetermined wavelength range, whereby the radiation incident on the energy conversion filter 78 absorbs a predetermined energy component.

  The energy conversion filter 78 is made of, for example, heavy metal such as copper, tungsten, or molybdenum, and has a thin plate shape (for example, a thickness of about 0.8 mm to 2.0 mm. The thickness is not limited to this, but is 2.0 mm or more. May be formed). The configuration of the energy conversion filter 78 is not limited to this, and any configuration that absorbs radiation having a desired wavelength can be applied.

  As described above, the radiation applied to the radiation detection panel 20 includes a high energy component having a relatively high frequency and a low energy component having a relatively low frequency, and radiation image data of the high energy component in the radiation. Thus, a high-pressure image is obtained, and a low-pressure image is obtained from radiation image data of low energy components. By absorbing most of the low energy component with the energy conversion filter 78, an image (soft part image and bone part image) in which the soft tissue and the bone tissue are emphasized or separated is obtained (energy subtraction method). In the electronic cassette 10, a low energy component is absorbed by the energy conversion filter 78.

  The projecting member 76 provided in the panel unit 14 has a height that matches the thickness of the energy conversion filter 78, so that a gap formed between the panel unit 14 and the panel unit 16 is used for energy conversion. A filter 78 is placed (inserted). Such a protruding member 76 can be formed, for example, by sticking a sheet body formed in a thin disk shape to the surface of the panel unit 14.

  In the electronic cassette 10, radiation is applied to the imaging surface 82 </ b> C of the panel unit 16 by disposing the energy conversion filter 78 between the panel unit 14 and the panel unit 16 in the closed state of the panel units 14 and 16. Then, the radiation detection panel 20B in the panel unit 16 is irradiated with radiation including a high energy component and a low energy component. The radiation detection panel 20A in the panel unit 14 is irradiated with an energy conversion filter 78. The low energy component is absorbed and the high energy component radiation is irradiated.

  Therefore, in the electronic cassette 10, when the panel units 14 and 16 are closed, the radiation image data of the low pressure image is obtained from the radiation detection panel 20B of the panel unit 16, and the radiation image of the high pressure image is obtained from the radiation detection panel 20A of the panel unit 14A. Data is obtained.

  Next, the operation of the first embodiment will be described. A panel unit 14 and a panel unit 16 each provided with a radiation detection panel 20 are connected to the electronic cassette 10 by a hinge 62 so as to be openable and closable. An image can be captured. Note that the electronic cassette 10 may have a structure in which a handle is provided in the casing 12A of the panel unit 14 and the casing 12B of the panel unit 16, thereby making it easy to open and close the panel units 14 and 16. preferable.

  By the way, in the electronic cassette 10, an energy conversion filter 78 is arranged between the panel units 14 and 16 in a closed state in which the panel units 14 and 16 are overlapped. In the electronic cassette 10, the radiation is applied to the first surface 72 of the radiation detection panel 20B by irradiating the imaging surface 82C of the panel unit 16 with radiation while the panel units 14 and 16 are closed. Radiation image data corresponding to the radiation emitted from the panel 20B is obtained. Further, the radiation transmitted through the radiation detection panel 20B passes through the energy conversion filter 78 and is irradiated onto the first surface 72 of the radiation detection panel 20A of the panel unit 14.

  Here, the low energy component is absorbed by the energy conversion filter 78 and the radiation of the high energy component is irradiated onto the radiation detection panel 20A. In the electronic cassette 10, the radiation detection panel 20 </ b> B of the panel unit 16 also absorbs low energy component radiation. However, since the energy conversion filter 78 is provided, the radiation detection panel 20 </ b> A includes the low energy component radiation. Are reliably removed, and radiation containing only high energy components is irradiated.

  Therefore, in the electronic cassette 10, radiation image data by radiation including a low energy component and radiation image data by radiation having a high energy component, which are used in the energy subtraction method, can be obtained by one irradiation of radiation. By using these radiographic image data, a low-pressure image and a high-pressure image applied to diagnosis using the energy subtraction method can be obtained.

  Here, the panel unit 14 is provided with a protruding member 76 on the imaging surface 82 </ b> A facing the panel unit 16, and in a closed state where the panel unit 16 overlaps the panel unit 14, The energy conversion filter 78 can be arranged in parallel with each of the radiation detection panels 20A and 20B.

  At this time, since the projecting member 76 is provided at the peripheral portion of the imaging surface 82A of the panel unit 14, the energy conversion filter 78 between the panel units 14 and 16 may be displaced, the panel unit 14, It is prevented that it falls out of between 16. Further, in the electronic cassette 10, even if the energy conversion filter 78 is disposed between the panel units 14 and 16, no more pressure than necessary is applied to the imaging surfaces 82A and 82B, and the radiation detection panels 20A and 20B. The parallel state is maintained, and appropriate radiographic image data can be obtained.

  Such a protruding member 76 has a height corresponding to the thickness of the energy conversion filter 78, and therefore, it is possible to cause discomfort to the subject even when the panel units 14 and 16 are open. Absent. Here, the projecting member 76 is provided on the imaging surface 82A of the panel unit 14, but it may be provided separately on the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16. The height of each protruding member can be reduced to half of the required height.

  In the electronic cassette 10, a radiation absorbing plate 80 is provided between the control unit 18 and the radiation detecting panel 20 </ b> A, and radiation that has passed through the radiation detecting panel 20 </ b> A is absorbed by the radiation absorbing plate 80. Therefore, in the electronic cassette 10, generation of back scattered rays due to radiation that has passed through the radiation detection panel 20A is prevented, and high-quality radiation image data can be obtained.

  In the electronic cassette 10, when the radiation image data for energy subtraction is acquired, the first surfaces 72 of the radiation detection panels 20A and 20B are irradiated with radiation. Therefore, radiation image data with an equivalent image quality is obtained between the radiation detection panels 20A and 20B, and high-accuracy image diagnosis by energy subtraction is possible.

  On the other hand, in the electronic cassette 10, when the panel units 14 and 16 are closed, radiation image data can be acquired using only the radiation detection panel 20B on the panel unit 16 side. Further, in the electronic cassette 10, when the panel units 14 and 16 are in the open state, the imaging surface 82A of the panel unit 14 is opened. Therefore, by irradiating the imaging surface 82A of the panel unit 14 with radiation, Radiation image data corresponding to the irradiated radiation is obtained from the radiation detection panel 20A.

  In the electronic cassette 10, the control unit 50 and the power supply unit 70 are configured to include a large number of electronic components, and generate heat when operated by the power of the power supply unit 70. In addition, the electrical characteristics of the radiation detection panel 20 change due to temperature changes. Due to the heat generated from the control unit 50 and the power supply unit 70, the temperature of the radiation detection panel 20, particularly the radiation detection panel 20A, is likely to increase.

  The temperature rise of the radiation detection panel 20 may cause discomfort to the subject when the subject touches the panel unit 14 or the like. Further, in the radiation detection panel 20, an increase in noise due to a temperature rise causes a deterioration in the S / N ratio and an increase in dark current of the switching element 24 and the like. Furthermore, the temperature rise of the radiation detection panel 20 is caused by the radiation detection due to, for example, the layer peeling due to the deterioration of the adhesive due to the deformation, the breakage, the temperature change repeatedly due to the difference in the thermal expansion coefficient of each member forming the laminated structure The panel 20 is deteriorated.

  Here, in the electronic cassette 10, the control unit 18 is disposed in the panel unit 14, and the panel unit 16 is separated from the control unit 18. For this reason, in the electronic cassette 10, when imaging is performed with the radiation detection panel 20 </ b> B of the panel unit 16 in the closed state of the panel units 14 and 16, the radiation detection panel 20 </ b> B is affected by the heat generated from the control unit 18. Since it is not received, a high quality radiographic image can be captured.

  Further, in the electronic cassette 10, the heat generated in the panel unit 14 is transmitted to the panel unit 16 by connecting the panel units 14 and 16. At this time, if the panel units 14 and 16 are in the open state, the heat dissipation area is expanded, and not only the panel unit 14 but also the panel unit 16 is radiated to improve the heat dissipation effect.

  Thereby, in the electronic cassette 10, when the radiation detection panel 20A in the panel unit 14 is taken with the panel units 14 and 16 open, the panel unit 20A generates heat generated by the control unit 18. Since there is no influence, even in this case, it is possible to capture a high-quality radiographic image.

  In the control unit 18, when a radiographic image is continuously captured or a moving image is captured, a temperature rise easily occurs. In the electronic cassette 10, the radiation detection panels 20A and 20B are not affected by heat. Therefore, even when performing continuous imaging using the radiation detection panels 20A and 20B or moving image imaging, the quality is high. Images are obtained.

  Further, GOS hardly changes in sensitivity due to temperature change, but CsI changes in sensitivity due to temperature increase (for example, the sensitivity decreases by about 0.3% every time the temperature increases by 1 ° C.). Therefore, when the scintillator layer 28 is formed of CsI, if the temperature of the scintillator layer 28 changes greatly during moving image shooting (perspective shooting) in which continuous shooting is repeated, the sensitivity change of the scintillator layer 28 increases, and a series of moving image shooting is performed. In the image, the density difference between the image at the beginning of the frame and the last image becomes large, the visibility deteriorates, and the diagnostic accuracy also decreases. However, since the electronic cassette 10 according to the present embodiment performs moving image capturing with the radiation detection panel 20B of the panel unit 16, the heat of the control unit 18 is not easily transmitted to the radiation detection panel 20B. Therefore, the sensitivity due to the temperature change of CsI. Change can be suppressed.

  On the other hand, in the electronic cassette 10, the energy conversion filter 78 is attached to the panel unit 16. However, the configuration is not limited to this, and a configuration in which the energy conversion filter 78 is detachable can be employed. In this case, in the electronic cassette 10, when the panel units 14 and 16 are open, the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 face the same direction and are on the same surface.

  Thereby, in the electronic cassette 10, imaging using the radiation detection panel 20A of the panel unit 14 and the radiation detection panel 20B of the panel unit 16 is possible in the open state of the panel units 14 and 16. In this case, it is possible to capture an image with an area obtained by arranging two radiation detection panels 20A and 20B side by side, and the imaging area is expanded as compared with the case where one radiation detection panel 20 is used.

  At this time, the radiation detection panel 20A is irradiated with radiation on the first surface 72, and the radiation detection panel 20B is irradiated with radiation on the second surface 74. For this reason, when a difference in image quality occurs between the radiation image data obtained from the radiation detection panel 20 and the radiation image data obtained from the radiation detection panel 20B, it may be eliminated by performing predetermined image processing. .

  In the electronic cassette 10, the first surface 72 of the radiation detection panel 20A and the second surface 74 of the radiation detection panel 20B are opposed to each other when the panel units 14 and 16 are closed. The two surfaces 74 and the first surface 72 of the radiation detection panel 20B may be opposed to each other, whereby imaging using the two radiation detection panels 20A and 20B is performed with the panel units 14 and 16 open. When performed, radiation image data with equivalent image quality can be obtained.

  Here, as shown in FIG. 8, the radiation detection panel 20 is provided on the back side of the radiation incident surface by being irradiated with radiation from the side on which the scintillator layer 28 is formed (the first surface 72 side). When the so-called back side reading method (so-called PSS (Penetration Side Sampling) method) is used to read a radiation image with the TFT substrate 26, the scintillator layer 28 emits light more strongly on the upper surface side of the figure (opposite side of the TFT substrate 26), A so-called surface reading method (so-called ISS (Irradiation Side Sampling)) in which radiation is irradiated from the TFT substrate 26 side (second surface 74 side) and a radiation image is read by the TFT substrate 26 provided on the surface side of the radiation incident surface. ) Method), the radiation transmitted through the TFT substrate 26 is incident on the scintillator layer 28 and the TFT substrate 26 side of the scintillator layer 28 emits more strongly. To. Electric charges are generated in each sensor portion 35 provided on the TFT substrate 26 by the light generated in the scintillator layer 28. For this reason, the radiation detection panel 20 is closer to the light emission position of the scintillator layer 28 with respect to the TFT substrate 26 when the front side reading method is used than when the rear side reading method is used. Is expensive.

  In the radiation detection panel 20, when the photoconductive layer 30 is made of an organic photoelectric conversion material, the photoconductive layer 30 hardly absorbs radiation. For this reason, the radiation detection panel 20 according to the present embodiment suppresses a decrease in sensitivity to the radiation X because the amount of radiation absorbed by the photoconductive layer 30 is small even when radiation is transmitted through the TFT substrate 26 by the surface reading method. be able to. In the surface reading method, radiation passes through the TFT substrate 26 and reaches the scintillator layer 28. Thus, when the photoconductive layer 30 of the TFT substrate 26 is formed of an organic photoelectric conversion material, Since there is almost no absorption of radiation and attenuation of radiation can be suppressed to a low level, it is suitable for the surface reading method.

  Further, the amorphous oxide constituting the active layer 224 of the switching element 24 and the organic photoelectric conversion material constituting the photoconductive layer 30 can be formed at a low temperature. For this reason, the insulating substrate 22 can be formed of plastic resin, aramid, or bionanofiber that absorbs little radiation. Since the insulating substrate 22 formed in this way has a small amount of radiation absorption, a decrease in sensitivity to the radiation X can be suppressed even when the radiation is transmitted through the TFT substrate 26 by the surface reading method.

  Therefore, as shown in FIG. 9, the electronic cassette 10 arranges the radiation detection panel 20 </ b> A in the panel unit 14 so that the second surface 74 side is directed upward (upward in FIG. 9), and the panel unit 16. You may arrange | position so that the 2nd surface 74 side may face the upper side (paper surface upper side of FIG. 9) in the closed state of the inside radiation detection panel 20B.

  As a result, as shown in FIG. 10A, the electronic cassette 10 is closed because the radiation detection panel 20A in the panel unit 14 and the radiation detection panel 20B in the panel unit 16 are both in the closed state. High-quality images can be obtained by shooting the state. In this case, as shown in FIG. 10B, in the electronic cassette 10, the radiation detection panel 20A in the panel unit 14 is in the front surface reading mode in the open state, and the radiation detection panel 20B in the panel unit 16 is the back surface reading method. Although there is a difference in image quality between radiographic images taken by the radiation detection panel 20A and the radiation detection panel 20B in the open state, it may be eliminated by performing predetermined image processing.

  In addition, as shown in FIG. 11, the electronic cassette 10 arranges the radiation detection panel 20A in the panel unit 14 so that the first surface 72 side faces upward (upward on the paper surface in FIG. 11). 16 may be arranged so that the second surface 74 side faces upward (upward in the drawing in FIG. 11) with the radiation detection panel 20B inside 16 closed.

  As a result, as shown in FIG. 12A, the electronic cassette 10 is in the closed state, and the radiation detection panel 20B in the panel unit 16 becomes the surface reading method. When a radiographic image is taken, a low-pressure image that requires high image quality can be taken with high quality by the radiation detection panel 20B. Further, in this case, as shown in FIG. 12B, the electronic cassette 10 is in the open state, because both the radiation detection panel 20A in the panel unit 14 and the radiation detection panel 20B in the panel unit 16 are of the back side reading method. In the open state, there is no difference in image quality between the radiation images photographed by the radiation detection panel 20A and the radiation detection panel 20B.

  When the radiation detection panels 20A and 20B are arranged by the surface reading method, for example, as shown in FIG. 13, the radiation detection panel 20A is a housing inside the panel unit 14 so that the TFT substrate 26 is on the imaging surface 82A side. The radiation detection panel 20B may be affixed to the housing part inside the panel unit 16 so that the TFT substrate 26 is on the imaging surface 82B side. When the insulating substrate 22 is formed of a highly rigid plastic resin, aramid, or bionanofiber, the radiation detection panel 20 itself has a high rigidity, so that the casing of the panel unit 14 or the panel unit 16 can be formed thin. In addition, when the insulating substrate 22 is formed of a highly rigid plastic resin, aramid, or bionanofiber, the radiation detection panel 20 itself has flexibility, so that the radiation detection panel 20 is not easily damaged even when an impact is applied.

  The scintillator layers 28 of the radiation detection panels 20A and 20B may have the same configuration or different configurations. For example, all the scintillator layers 28 of the radiation detection panels 20A and 20B may be made of GOS. In this case, the electronic cassette 10 can be manufactured at low cost.

  Alternatively, all of the scintillator layers 28 of the radiation detection panels 20A and 20B may be formed of columnar crystals of CsI or the like. In this case, since light generated in the columnar crystal by being irradiated with radiation is guided along the columnar crystal, the image quality can be improved.

  Further, the scintillator layer 28 of the radiation detection panel 20B in the panel unit 16 may be constituted by a columnar crystal made of CsI or the like, and the scintillator layer 28 of the radiation detection panel 20A in the panel unit 14 may be constituted by GOS. In this case, with the electronic cassette 10 in the closed state, the radiation image for energy subtraction is obtained by the panel units 14 and 16 by the radiation irradiation once, and the radiation detection panel 20B obtains a high-quality and low-energy radiation line image. Can do. In addition, even if a temperature change occurs in the panel unit 14, it is possible to suppress a change in the image quality of the radiographic image captured by the panel unit 14.

  Further, in the radiating electron cassette 10, due to the structure of the hinge 62, a gap is generated between the radiation detection panels 20 </ b> A and 20 </ b> B when the panel units 14 and 16 are opened. Thereby, a gap is generated between the image of the radiation image data obtained from the radiation detection panel 20A and the image obtained from the radiation image data of the radiation detection panel 20B. In this case, if the image obtained from the radiation detection panel 20A and the image obtained from the radiation detection panel 20B are continuous, an image of this gap portion is generated by image processing or the like to obtain a continuous image. Can do. Further, at the time of imaging, it is only necessary to avoid the attention site (main imaging site) from overlapping the gap portion. In addition, you may make it the structure which does not produce the clearance gap between radiation detection panel 20A, 20B substantially by the structure of the hinge which connects the panel units 14 and 16. FIG.

  In the electronic cassette 10, the control unit 18 and the radiation absorbing plate 80 are provided in the panel unit 14. However, the present invention is not limited thereto, and the control unit 18 may be provided separately. In this case, the panel units 14 and 16 are closed. Thus, if the radiation absorbing plate 80 as another example of the filter member is inserted and arranged between the panel units 14 and 16, separate radiation image data can be obtained by the radiation detection panels 20A and 20B.

Further, the control unit 18 is provided with mechanical detection means such as a limit switch for detecting the open / closed state (closed state or open state) of the panel units 14 and 16, and this detection means is connected to the cassette control unit 58. You may make it do. Accordingly, the cassette control unit 58 can recognize what kind of image data the radiation image data detected by the radiation detection panels 20A and 20B is, and can be configured to switch the processing according to the recognition result. .
[Second Embodiment]
The second embodiment will be described below. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  FIG. 14 shows a cassette 10A according to the second embodiment. The cassette 10A includes a panel unit 14 in which a control unit 18, a radiation detection panel 20A, and a radiation absorbing plate 80 are accommodated in a housing 12A. The electronic cassette 10 </ b> A includes a panel unit 16 </ b> A in which a radiation detection panel 20 </ b> B and an energy conversion filter 78 are accommodated in a housing 12 </ b> B, and the panel unit 14 and the panel unit 16 </ b> A are connected by a hinge 62.

  Thus, in the electronic cassette 10A, the closed state in which the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16A are opposed to each other and the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 are It is connected so that rotation is possible so that it can take the open state which faces to the same direction on the same surface.

  In the panel unit 16, the energy conversion filter 78 is disposed on the imaging surface 82B side of the housing 12B. Thereby, in the electronic cassette 10A, the radiation detection panel 20B, the energy conversion filter 78, and the radiation detection panel 20A are arranged in this order in the closed state with the panel units 14 and 16A closed.

  In the electronic cassette 10A configured as described above, radiation is applied to the imaging surface 82C of the panel unit 16A in a closed state of the panel units 14 and 16A, so that the radiation detection panel 20B has only high energy components. Radiation image data including low energy components can be obtained.

  Further, in the electronic cassette 10A, the energy conversion filter 78 is provided in the panel unit 16A, so that the radiation that has passed through the radiation detection panel 20B passes through the energy conversion filter 78, thereby reducing the low energy component. The radiation of high energy component is absorbed and the radiation detection panel 20A in the panel unit 14 is irradiated with radiation of high energy component, and radiation image data of high energy component is obtained.

  Therefore, also in the electronic cassette 10A, the radiation image data of the low pressure image is obtained from the radiation detection panel 20B, and the radiation image data of the high pressure image is obtained from the radiation detection panel 20A. Radiation image data used for the above is obtained.

  On the other hand, in the first and second embodiments, as an example of the radiation detection panel, after the radiation is once converted into light by the scintillator layer 28, the converted light is converted into electric charge by the photoconductive layer 30 and accumulated. Although the conversion type radiation detection panel 20 has been described, the present invention is not limited to this. For example, a direct-conversion radiation detection panel that directly converts radiation into charges by a sensor unit using amorphous selenium or the like may be used.

FIG. 15 shows an example of a direct conversion radiation detection panel 21. In the radiation detection panel 21, a photoconductive layer 102 that converts incident radiation into electric charges is formed on the TFT substrate 26. As the photoconductive layer 102, amorphous Se, Bi ₁₂ MO ₃₀ (M: Ti, Si, Ge), Bi ₄ M ₃ O ₁₂ (M: Ti, Si, Ge), Bi ₂ O ₃ , BiMO ₄ (M: Nb, Ta, V), Bi ₂ WO ₆ , Bi ₂₄ B ₂ O ₃₉ , ZnO, ZnS, ZnSe, ZnTe, MNbO ₃ (M: Li, Na, K), PbO, HgI ₂ , PbI ₂ , CdS, CdSe , CdTe, BiI ₃ , GaAs, and the like are used as a main component, but they have high dark resistance and show good photoconductivity against X-ray (radiation) irradiation. Therefore, an amorphous material capable of forming a large area film at a low temperature is suitable.

  A bias electrode 104 for applying a bias voltage to the photoconductive layer 102 is formed on the photoconductive layer 102 on the surface side of the photoconductive layer 102. Further, on the TFT substrate 26, as in the indirect conversion type radiation detection panel 20, a charge collection electrode 34 that collects charges generated in the photoconductive layer 102 is formed. Further, the TFT substrate 26 of the direct conversion type radiation detection panel 21 is provided with a charge storage capacitor 106 for storing charges collected by the charge collection electrodes 34. The charge accumulated in each charge storage capacitor 106 is read when the switching element 24 is turned on.

  Here, in the electronic cassette 10A, the radiation detection panel provided in the panel unit 14 and the radiation detection panel provided in the panel unit 16A may be different. At this time, the radiation detection panel 21 may be provided in the panel unit 16A.

  In the radiation detection panel 20 having the scintillator layer 28 containing GOS and CsI, high-quality radiation image data can be obtained, but there are not a few low-energy component radiations that are transmitted without being absorbed. On the other hand, in the radiation detection panel 21 having the photoconductive layer 102 containing amorphous selenium, in addition to obtaining high-quality radiation image data, the absorption rate of radiation of low energy components is extremely high, and the transmitted low energy is low. Although the amount of the component radiation is greater than that of the energy conversion filter 78, the amount is extremely small.

  From here, the energy conversion filter can be omitted by using the radiation detection panel 21 in place of the radiation detection panel 20B in the panel unit 16A or the panel unit 16. Thereby, weight reduction of the electronic cassettes 10 and 10A can be achieved.

Moreover, in such an electronic cassette 10, 10A, it is possible to perform imaging using the radiation detection panel 20A and the radiation detection panel 21 at the same time when the panel units 14, 16 or the panel units 14, 16A are opened.
[Third Embodiment]
A third embodiment will be described below. Note that the basic configuration of the third embodiment is the same as that of the first embodiment described above. In the third embodiment, the first embodiment has the same configuration as the first embodiment. The same reference numerals as those of the embodiment are given and the description thereof is omitted. In the third embodiment, the radiation detection panel 21 may be used instead of the radiation detection panel 20.

  FIGS. 16, 17A, and 17B show an electronic cassette 10B according to a third embodiment. As shown in FIGS. 17A and 17B, the cassette 10B includes a panel unit 14 in which a control unit 18, a radiation detection panel 20A, and a radiation absorbing plate 80 are housed in a housing 12A. I have. The electronic cassette 10B includes a panel unit 16 in which a radiation detection panel 20B is accommodated in a housing 12B, and the panel unit 14 and the panel unit 16 are connected by a hinge portion 83.

  Accordingly, in the electronic cassette 10B, the panel units 14 and 16 are rotated about the shaft 83A of the hinge portion 83, whereby the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 are opposed to each other. The state and the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 can be in an open state in which they are directed in the same direction on the same surface.

  In addition, as shown in FIGS. 16, 17A, and 17B, in the electronic cassette 10B, an energy conversion filter 78A is disposed between the panel unit 14 and the panel unit 16. As shown in FIGS. 16 and 17B, the energy conversion filter 78A is rotatable about the shaft 83A and is connected to the hinge portion 83. Further, the energy conversion filter 78A has the same basic configuration as the energy conversion filter 78, and the energy conversion filter 78A is connected to the hinge portion 83 and is rotatable. Different from the filter 78.

  As a result, the energy conversion filter 78A can rotate between the position in contact with the imaging surface 82A of the panel unit 14 and the position in contact with the imaging surface 82B of the panel unit 16 when the panel units 14 and 16 are in the open state. It has become. Therefore, as shown in FIG. 17A, also in the electronic cassette 10B, when the panel units 14 and 16 are closed, the radiation detection panel 20B, the energy conversion filter 78A, and the radiation detection panel 20A are layered in this order. Placed in.

  In the electronic cassette 10A configured as described above, radiation is applied to the imaging surface 82C of the panel unit 16 in a closed state of the panel units 14 and 16, so that the radiation detection panel 20B has only high energy components. Radiation image data including low energy components can be obtained.

  Further, in the electronic cassette 10B, the panel unit 14 is rotated by rotating the energy conversion filter 78A to the panel unit 16 side and retracting from the imaging surface 82A of the panel unit 14 with the panel units 14 and 16 open. The radiation detection panel 20A can be imaged, and the energy conversion filter 78A is rotated to the panel unit 14 side and retracted from the imaging surface 82B of the panel unit 16, whereby the radiation detection panel of the panel unit 16 is retreated. Imaging using 20B becomes possible.

  Further, in the electronic cassette 10B, when the panel units 14 and 16 are in the open state, the energy conversion filter 78A is tilted toward the panel unit 14 and placed on the imaging surface 82A, whereby the first radiation detection panel 20A of the panel unit 14 is placed. Radiation image data based on radiation of a high energy component is obtained from the radiation applied to the surface 72, and the energy conversion filter 78A is tilted toward the panel unit 16 and placed on the imaging surface 82B. Radiation image data based on radiation of a high energy component is obtained from radiation irradiated on the first surface 72 of 20B.

  Since the energy conversion filter 78A is connected to the panel unit 14 via the hinge 83, the electronic cassette 10B generates heat generated from the control unit 18 in the panel unit 14 via the energy conversion filter 78A. It can dissipate heat. That is, in the electronic cassette 10, the heat dissipation efficiency can be improved by using the energy conversion filter 78 </ b> A used in the energy subtraction method as a heat sink.

Therefore, also in the electronic cassette 10B, high-quality radiation image data that is not affected by the heat generated from the control unit 18 while preventing the radiation detection panel 20 from being deteriorated due to the heat generated from the control unit 18. Is obtained.
[Fourth Embodiment]
A fourth embodiment will be described below. The fourth embodiment has the same basic configuration as that of the first embodiment described above. In the fourth embodiment, the first embodiment has the same configuration as that of the first embodiment. The same reference numerals as those in the embodiment are given and the description thereof is omitted. In the fourth embodiment, the radiation detection panel 21 may be used instead of the radiation detection panel 20.

  18, 19A and 19B show an electronic cassette 10C according to a fourth embodiment. As shown in FIGS. 19A and 19B, the cassette 10C includes a panel unit 14 in which a control unit 18, a radiation detection panel 20A, and a radiation absorbing plate 80 are housed in a housing 12A. I have. The electronic cassette 10C includes a panel unit 16 in which a radiation detection panel 20B is accommodated in a housing 12B and an energy conversion filter 78 is provided on one surface (imaging surface 82B). The panel unit 16 is connected by a hinge portion 91.

  As shown in FIG. 18, FIG. 19 (A) and FIG. 19 (C), the hinge portions 91 are provided in pairs on both ends of one side of the connected panel units 14 and 16 (in each figure, Only one is shown). The hinge portion 91 includes a connecting bar 92, and pins 93 </ b> A and 93 </ b> B are pivotally supported at both ends of the connecting bar 92.

  Here, the one pin 93A pivotally supported by the connecting bar 92 is connected to the housing 12A of the panel unit 14, so that the connecting bar 92 can rotate to the panel unit 14 around the pin 93A. It is connected to. The other pin 93B pivotally supported by the connecting bar 92 is connected to the housing 12B of the panel unit 16, so that the connecting bar 92 can rotate to the panel unit 16 about the pin 93B. It is connected.

  In the electronic cassette 10 </ b> C, the panel units 14 and 16 are connected by such a hinge portion 91, and the imaging unit 82 and the imaging unit 82 </ b> B of the panel unit 14 face each other, The surface 82A and the imaging surface 82B of the panel unit 16 can be open in the same direction. Accordingly, as shown in FIG. 19A, also in the electronic cassette 10C, when the panel units 14 and 16 are closed, the radiation detection panel 20B, the energy conversion filter 78, and the radiation detection panel 20A are layered in this order. Placed in.

  As a result, in the electronic cassette 10C, the radiation image data (high-pressure image data and low-pressure image data) used in the energy subtraction method by the radiation detection panel 20A and the radiation detection panel 20B with the panel units 14 and 16 closed. ) Is obtained. Further, in the electronic cassette 10 </ b> C, imaging using the radiation detection panel 20 </ b> A in the panel unit 14 and the radiation detection panel 20 </ b> B in the panel unit 16 is possible.

  On the other hand, in the electronic cassette 10C, when the panel units 14 and 16 are in the open state, the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 are not on the same plane. , 16 are placed on an imaging base (not shown), the panel units 14 and 16B are in contact with the upper surface of the base.

  At this time, since the base is flat, as shown in FIGS. 18 and 19B, in the electronic cassette 10C, the imaging surface 82A of the panel unit 14 and the imaging surface 82B of the panel unit 16 are separated. There is a step between them. This level difference is caused by the difference between the height of the casing 12A of the panel unit 14 and the height of the casing 12B of the panel unit 16.

Such a step creates a space between the extended surface of the imaging surface 82A of the panel unit 14 and the surface of the energy conversion filter 78 of the panel unit 16 in the open state of the panel units 14 and 16. In such a space, for example, to protect the energy conversion filter 78, to prevent the subject from touching the energy conversion filter 78, by covering the panel unit 16 not used for imaging. A cover or the like for preventing an unnecessary step can be provided. In the fourth embodiment, a panel unit 16A in which an energy conversion filter 78 is accommodated may be applied instead of the panel unit 16.
[Fifth Embodiment]
The fifth embodiment will be described below. Note that in the fifth embodiment, identical symbols are assigned to configurations equivalent to those in the first embodiment and descriptions thereof are omitted. In the fifth embodiment, the radiation detection panel 21 can be used instead of the radiation detection panel 20.

  20A and 20B show an electronic cassette 84 according to the fifth embodiment. The electronic cassette 84 includes a housing 12A and a housing 12C and is connected by a hinge 62. The casing 12A is provided with a control unit 18A, a radiation detection panel 20A, and a radiation absorbing plate 80, and a panel unit 14A is configured. The housing 12C corresponds to the housing 12B and accommodates the radiation detection panel 20B to form a panel unit 16B.

  The basic configuration of the control unit 18A is the same as that of the control unit 18, but the display unit 66 is omitted in the electronic cassette 84, and the control unit 50A is different from the control unit 50 in this respect. In the fifth embodiment, the display unit 66 is omitted. However, the present invention is not limited to this. For example, a configuration in which a display unit is provided on the side surface of the housing 12A may be used.

  As shown in FIG. 20A, in the electronic cassette 84, the first surface 72 of the radiation detection panel 20A and the second surface 74 of the radiation detection panel 20B face each other in a closed state in which the panel units 14A and 16B are overlapped. The Also, in the electronic cassette 84, the energy conversion filter 78 is disposed between the panel units 14A and 16B in the closed state of the panel units 14A and 16B. Radiation image data and radiation image data of a low energy component are obtained (radiation image data of a high pressure image and a low pressure image used in the energy subtraction method).

  As shown in FIGS. 20A and 20B, the panel unit 16B has a grid 88 formed on the imaging surface 82D corresponding to the imaging surface 82C. That is, the panel unit 16B of the electronic cassette 84 has a configuration in which the grid 88 is provided on the panel unit 16 of the electronic cassette 10 described above, for example. The grid 88 removes scattered radiation of radiation caused by the imaging target from the radiation (arrow A) irradiated to the imaging surface 82D of the panel unit 16B. Note that any configuration can be applied to the grid 88 as long as the configuration removes scattered radiation from radiation.

  As shown in FIG. 20B, the height of the grid 88 provided in the electronic cassette 84 (height along the radiation irradiation direction) matches the height of the panel unit 16B with the height of the panel unit 14A. It is raised so as to make it.

  In the electronic cassette 84 configured as described above, the radiation detection panel 20A and the radiation image data of the high pressure image and the radiation image data of the low pressure image used for the energy subtraction method are obtained by one radiation irradiation. Radiation is irradiated perpendicularly to each first surface 72 of the radiation detection panel 20B. Therefore, image quality deterioration due to scattered light does not occur, and a high-quality radiation image can be obtained.

  On the other hand, in the electronic cassette 84, by providing the grid 88 on the panel unit 16B, the bulk of the panel unit 16B (height along the radiation direction) is increased. Accordingly, as shown in FIG. 20B, in the electronic cassette 84, the height of the imaging surface 82B of the panel unit 16B is equal to the height of the imaging surface 82A of the panel unit 14A in the open state of the panel units 14A and 16B. Match.

  When the electronic cassette 84 performs imaging with the panel units 14A and 16B open, the imaging surfaces 82A and 82B (the first surface 72 of the radiation detection panel 20A and the second surface 74 of the radiation detection panel 20B) are on the same plane. In addition, the electronic cassette 84 does not become unstable (no rattling) when the same plane is used. Therefore, the electronic cassette 84 does not cause the subject to feel uneasy due to instability when the subject is placed on the panel units 14A and 16B in the open state.

In the electronic cassette 84, the energy conversion filter 78 may be attached in advance to the imaging surface 82B of the panel unit 16B, and the energy conversion filter 78 is accommodated together with the radiation detection panel 20B. It may be.
[Sixth Embodiment]
Next, a sixth embodiment will be described. Note that the basic configuration of the sixth embodiment is the same as that of the first embodiment, and in the sixth embodiment, the same reference numerals are given to the configurations equivalent to those of the first embodiment. The explanation is omitted. Also in the sixth embodiment, a configuration using the radiation detection panel 21 instead of the radiation detection panel 20 may be taken.

  FIG. 21 shows an electronic cassette 90 according to the sixth exemplary embodiment. The electronic cassette 90 includes a housing 12D and a housing 12B and is connected by a hinge 62. The housing 12D is provided with a control unit 18, a radiation detection panel 20A, and a radiation absorbing plate 80, thereby forming a panel unit 14B.

  In the electronic cassette 90, the first surface 72 of the radiation detection panel 20A and the second surface 74 of the radiation detection panel 20B face each other in a closed state in which the panel units 14B and 16 are overlapped. Further, in the electronic cassette 90, the energy conversion filter 78 is disposed between the panel units 14B and 16 in the closed state of the panel units 14B and 16, so that the high energy component can be obtained by one irradiation of radiation. Radiation image data and radiation image data (radiation image data used for the energy subtraction method) using low energy components are obtained.

  In the panel unit 14B, a convex portion 94A is formed on a bottom surface 94 that is a surface (non-radiation irradiation surface) opposite to the imaging surface 82A. Accordingly, a recess (not shown) is formed in the bottom surface 94 in the panel unit 14B, and the control unit 50 and the power supply unit 70 that form the control unit 18 are accommodated in the recess.

  In addition, a large number of fins 96 (fins 96A and 96B) as an example of a heat radiating unit are formed on the bottom surface 94 of the panel unit 14B at predetermined intervals. In the fin 96, a fin 96A is formed on the peripheral edge of the convex portion 94A of the bottom surface 94, and a fin 96B is formed on the convex portion 94A. The fin 96A is longer (higher) than the fin 96B, and the tips of the fins 96A and 96B are on the same plane.

  Also in the electronic cassette 90 configured in this manner, radiation is applied to the first surface 72 of the radiation detection panel 20A and the second surface 74 of the radiation detection panel 20B with the panel units 14B and 16 open. Radiation image data of an image continuous between the detection panels 20A and 20B is obtained. Further, in the electronic cassette 90, when the panel units 14B and 16 are in the closed state, the energy conversion filter 78 is disposed between the panel unit 14B and the panel unit 16, so that a high pressure can be obtained by one irradiation of radiation. Radiation image data for images and radiation image data for low-pressure images can be obtained.

  On the other hand, as described above, the control unit 50 and the power supply unit 70 are configured to include a large number of electronic components, and generate heat when operated by the power of the power supply unit 70. In addition, the electrical characteristics of the radiation detection panel 20 change due to temperature changes. The radiation detection panel 20, particularly the radiation detection panel 20 </ b> A, is likely to increase in temperature due to heat generated from the control unit 50 and the power supply unit 70, and when the subject touches the electronic cassette 90, the subject feels uncomfortable. There are things to do.

  Here, in the electronic cassette 90, a convex portion 94A is formed on the bottom surface 94 of the panel unit 14B, and the control unit 18 (control unit 50, power source unit) generates heat in the concave portion generated in the panel unit 14B by the convex portion 94A. 70). Thereby, the heat generated from the control unit 18 is released from the convex portion 94 </ b> A of the bottom surface 94. Further, in the electronic cassette 90, a large number of fins 96 are formed on the bottom surface 94 of the housing 12D to improve heat dissipation efficiency.

  Thereby, in the electronic cassette 90, the temperature rise of the radiation detection panel 20B of the panel unit 16 as well as the radiation detection panel 20A of the panel unit 14B is suppressed. Therefore, in the electronic cassette 90, even when the control unit 18 is integrally provided, the radiation detection panels 20A and 20B are prevented from being deteriorated due to a temperature rise, and noise components included in the radiation image data are suppressed. A high-quality radiographic image is obtained from the radiographic image data output from the detection panels 20A and 20B.

  In the electronic cassette 90, it is possible to prevent the height of the panel unit 14B from being formed by forming the convex portions 94A on the bottom surface 94 of the housing 12D and providing the fins 96, but the panel units 14B and 16 are open. It is preferable to stabilize by suppressing the difference in height between the panel units 14B and 16. In this case, a leg member is provided on the side surface of the panel unit 16 having a lower height (a direction intersecting the radiation irradiation direction), and the leg member supports the panel unit 16 when the panel unit 16 is opened. A configuration to be applied can be applied.

  Also in the electronic cassette 90, the energy conversion filter 78 may be previously attached to the imaging surface 82B of the panel unit 16, and the energy conversion filter 78 is accommodated together with the radiation detection panel 20B. It may be.

  In the electronic cassettes 10, 10 </ b> A to 10 </ b> C, 84, 90 of the above-described embodiments, connecting means such as the hinge 62, the hinge part 83, the hinge part 91, and the like connect the panel units 14, 16 detachably. Also good.

  FIG. 22 shows a case where the panel units 14 and 16 of the electronic cassette 10 are detachably connected.

  The panel unit 16 is provided with a flat plate-like connecting member 250 having flexibility at the upper part of one side. The panel unit 14 is provided with an insertion port 252 capable of accommodating the connection member 250 at an upper portion of one side, and the connection member 250 can be locked in the insertion port 252. The connection member 250 is provided with various wirings and power supply lines, and the insertion opening 252 is provided with electrodes corresponding to the various wirings and power supply lines of the connection member 250.

  In the electronic cassette 10, the connecting member 250 of the panel unit 16 is inserted into the insertion port 252 of the panel unit 14 and locked, so that the connecting member 250 functions as a connecting means, and the panel unit 16 and the panel unit 14 are connected to each other. It is connected so that it can be opened and closed. Further, in the electronic cassette 10, the panel unit 16 and the panel unit 14 are electrically connected when the connection member 250 is inserted into the insertion port 252 and various wirings and power supply lines come into contact with the corresponding electrodes.

  In FIG. 22, the case where the panel unit 16 and the panel unit 14 are connected so as to be openable and closable by using the connecting member 250 as a flexible member has been described. One of the fixing portions to be fixed may be detachable, and any mechanism may be used as long as the panel units 14 and 16 can be detachably connected.

  In the above embodiment, the case where the panel unit 14 has a flat plate shape has been described, but the present invention is not limited to this. For example, the radiation detection panel 20 can be formed on a glass substrate or the like like a liquid crystal display, and can be made relatively thin. On the other hand, the panel unit 14 has a built-in control unit 18, and a circuit element such as an inductance or a coil or a battery built in the control unit 18 is higher than the radiation detection panel 20. For this reason, the panel unit 14 is formed thicker than the panel unit 16.

  Therefore, as shown in FIGS. 23 and 24, the panel unit 16 is formed thin. Further, the casing 12A of the panel unit 14 is formed longer than the panel unit 16, and the radiation detection panel 20A is disposed in the overlapping portion 150 where the panel unit 16 is folded and overlapped when the panel unit 16 is closed. The non-overlapping portion 152 is formed to have substantially the same thickness as the panel unit 16 and does not overlap with the panel unit 16 when the panel unit 16 is in the closed state. May be arranged. Also in this case, the panel units 14 and 16 may be detachably connected. For example, the panel unit 14 may be attached when shooting is usually performed with the panel unit 14 and shooting of energy subtraction with one shot or shooting with a large area is required. Since the control unit 18 is built in and activated on the panel unit 14 side, it is possible to take a picture immediately after installation.

  In the present embodiment described above, the configuration of the present invention is not limited. The radiation imaging apparatus according to the present invention can apply any combination of the panel units of the electronic cassettes 10, 10A to 10C, 84, and 90 applied to the present embodiment. In addition, the configurations of the electronic cassettes 10, 10A to 10C, 84, 90 and the radiation detection panels 20, 21 are merely examples, and it is needless to say that the configurations can be appropriately changed without departing from the gist of the present invention. .

10, 10A, 10B, 10C, 10D, 84, 90 Electronic cassette 14, 14A, 14B Panel unit (first panel unit)
16, 16A, 16B Panel unit (second panel unit)
18, 18A Control unit 20 (20A, 20B), 21 Radiation detection panel 50, 50A Control unit 62 Hinge (connection means)
64 Transmission / Reception Unit 66 Display Unit 70 Power Supply Unit 72 First Surface 74 Second Surface 76 Projecting Member 78, 78A Energy Conversion Filter (Filter Member)
80 Radiation absorbing plate (radiation absorbing member)
82A-82D Imaging surface 83 Hinge part (connection means)
88 Grid 91 Hinge (connecting means)
94A Convex part (heat dissipation means)
96 (96A, 96B) Fin (heat dissipation means)

Claims (13)

A first panel unit in which one side of the radiation detection panel is directed to one side and the radiation detection panel is accommodated;
A second panel unit in which the other surface of the radiation detection panel is directed to one surface and the radiation detection panel is accommodated;
A closed state in which one end of the first panel unit and one end of the second panel unit are opposed to one surface of the first panel unit and one surface of the second panel unit; And a connecting means for rotatably connecting so that one surface of the first panel unit and one surface of the second panel unit are in an open state in which the one surface is directed in the same direction;
A filter member disposed between the radiation detection panel of the first panel unit in the closed state and the radiation detection panel of the second panel unit to absorb a predetermined energy component from incident radiation; ,
A radiation imaging apparatus including: The filter member is disposed between the first panel and the second panel;
The radiation imaging apparatus according to claim 1. The filter member is connected to the connecting means and is disposed so as to be rotatable between the first panel unit and the second panel unit.
The radiation imaging apparatus according to claim 2. The filter member is housed in the second panel unit;
The radiation imaging apparatus according to claim 1. A control unit composed of a control unit and a power supply unit,
In the first panel unit, the radiation detection panel accommodated in the first panel unit is accommodated at a position on the other surface side.
The radiation imaging apparatus according to any one of claims 1 to 4. A flat radiation absorbing member that is provided between the radiation detection panel and the control unit in the first panel unit and prevents back scattering during imaging;
The radiation imaging apparatus according to claim 5. A flat grid is provided on the other surface of the second panel unit to remove scattered radiation from the imaging target during imaging.
The radiation imaging apparatus according to claim 5 or 6. A heat dissipating means formed on the other surface of the first panel unit for releasing heat generated by the control unit;
The radiation imaging apparatus according to any one of claims 5 to 7. Provided on at least one peripheral edge of one surface of the first panel unit and one surface of the second panel unit, and in the closed state between the first panel unit and the second panel unit Including a projecting member forming a gap between which the filter member is disposed,
The radiation imaging apparatus according to claim 1 or 2. The radiation detection panel is a scintillator that converts radiation into light, converts the radiation into light, and outputs an electrical signal indicating a radiation image represented by the light,
The radiation imaging apparatus according to claim 1, wherein the scintillator includes a columnar crystal of a phosphor material. The radiation imaging apparatus according to claim 10, wherein the phosphor material is CsI. In the radiation detection panel, a sensor part that generates charges by receiving light converted by the scintillator and a thin film transistor for reading out the charges generated by the sensor part are formed on an insulating substrate.
The sensor unit includes an organic photoelectric conversion material,
The active layer of the thin film transistor includes an amorphous oxide or an organic semiconductor material or a carbon nanotube,
The radiation imaging apparatus according to claim 10, wherein the substrate is made of plastic. The radiation imaging apparatus according to claim 1, wherein the connection unit removably connects the first panel unit and the second panel unit.

Images