JP2010071931A - Radiographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively reduce the thermal impact of a heat-generating source given to a radiation detector. <P>SOLUTION: A circuit 124 for signal amplification or a heat-generating source, a signal processing substrate 122, a circuit board 128 with a power supply circuit 129, a gate line driver 126, the power supply circuit 129 and the cooling fan 142 are arranged on a second chassis 112 to be isolated from a radiation detector 400. The heat from the circuit 124 for signal amplification, particularly with high calorific power is diffused into the second chassis 112 through a heat discharge member 140. The heat which has diffused into the second chassis 112 is cooled, by having a cooling fan 142 circulates external air through the second chassis 112. hence, high heat-discharging efficiency is attained to diffusion of heat from the heat generating source and effectively reduces the influence from heat of a heat source to the radiation detector 400. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiation imaging apparatus used for a medical X-ray imaging apparatus or the like.

As a radiation imaging apparatus, configurations disclosed in Patent Document 1 and Patent Document 2 are known.
In the configuration of Patent Document 1, the heat generation source and the radiation detection device are held in the first housing via a heat insulating material. The heat generated from the heat generation source in the first casing is cooled by an air cooling fan installed in the second casing that covers the surface of the first casing.

  In the configuration of Patent Document 2, a heat insulating means is provided between a heat source such as a circuit and the radiation detector. A fan is installed in the vicinity of the heat sink.

As described above, in the configurations of Patent Document 1 and Patent Document 2, the radiation detection device and the heat generation source such as the signal processing integrated circuit are installed close to each other in the same housing, and the heat conducting member such as the heat radiating plate is installed. The heat was radiated to the outside.
JP 2003-194951 A JP 2000-116633 A

  However, the heat generation from the integrated circuit is a level that cannot be ignored. In the heat radiation modes such as Patent Document 1 and Patent Document 2, the heat shielding from the heat source to the radiation detection device is not sufficient, and the device durability deteriorates or is integrated. There is a concern of image deterioration due to circuit heating.

  In view of the above fact, an object of the present invention is to effectively reduce the influence of heat from a heat source on a radiation detector.

  The radiation imaging apparatus according to claim 1 of the present invention includes a first housing in which a radiation detector for detecting radiation is housed, a second housing in which a heat source is housed, and the second housing. And a heat radiating member provided in the body and dissipating heat of the heat source by contacting the heat source.

  According to this configuration, the heat source is isolated from the radiation detector, and the heat of the heat source is dissipated by the heat radiating member. For this reason, the heat dissipation efficiency which dissipates the heat of the heat source is good, and the influence of the heat of the heat source on the radiation detector can be effectively reduced.

  According to a second aspect of the present invention, there is provided the radiation imaging apparatus according to the first aspect, further comprising a cooling unit that circulates a cooling fluid in the second casing and cools the second casing.

  According to this configuration, since the inside of the second housing is cooled, the heat of the heat source is cooled, and the influence of the heat of the heat source on the radiation detector can be effectively reduced.

  A radiation imaging apparatus according to a third aspect of the present invention is the radiation imaging apparatus according to the first or second aspect, wherein the heat dissipation member is not in contact with the second housing, and the heat generation source is within the second housing. Dissipate heat.

According to this configuration, the heat dissipation member dissipates heat from the heat generation source in the second housing. The cooling means
The heat dissipated in the second housing is cooled.

  For this reason, the heat dissipation efficiency which dissipates the heat of the heat source is good, and the influence of the heat of the heat source on the radiation detector can be effectively reduced.

  According to a fourth aspect of the present invention, in the radiation imaging apparatus according to any one of the first to third aspects, a heat insulating member is provided between the first casing and the second casing.

  According to this configuration, since the heat insulating member is provided between the first housing and the second housing, heat is not easily transmitted from the heat source in the second housing to the radiation detector in the first housing. The influence of the heat of the heat source on the radiation detector can be effectively reduced.

  According to a fifth aspect of the present invention, there is provided the radiographic apparatus according to any one of the first to fourth aspects, wherein the heat generation source is a signal amplification circuit that amplifies an electric signal from the radiation detector, A signal processing board for processing an electric signal from the detector, a power supply circuit for supplying electric power to the radiation detector, and a switching element driver for inputting a signal to a switching element for reading out electric charges converted from the radiation.

  As the heat generation source, a signal amplification circuit, a signal processing board, a power supply circuit, and a switching element driver are conceivable. The radiation detector is isolated from the radiation detector by the second housing and diffused by the heat radiating member. It is possible to effectively reduce the influence of the heat of the heat generation source.

  According to a sixth aspect of the present invention, in the configuration of the fifth aspect, the heat radiating member is disposed in the signal amplification circuit.

  According to this configuration, since the signal amplification circuit generally becomes a heat generation source with a large amount of heat generation, the influence of the heat of the heat generation source exerted on the radiation detector is effectively reduced by dissipating this with the heat dissipation member. can do.

  The radiation imaging apparatus according to a seventh aspect of the present invention is the radiographic apparatus according to any one of the first to sixth aspects, wherein a flexible cable that transmits an electrical signal from the radiation detector to a circuit in the second housing is provided. It is fixed to at least one of the first casing and the second casing.

  According to this configuration, the flexible cable that transmits the electrical signal from the radiation detector to the circuit in the second housing is fixed to at least one of the first housing and the second housing, and thus does not move in a fluttering manner. Therefore, the influence of noise on the radiation detector can be reduced.

  Since this invention was set as the said structure, the influence of the heat | fever of the heat source which gives to a radiation detector can be reduced effectively.

Hereinafter, an example of an embodiment of a radiation imaging apparatus according to the present invention will be described with reference to the drawings.
First, the configuration of the radiation detector provided in the radiation imaging apparatus 100 according to the present embodiment will be described.

  The radiation detector according to the present embodiment is used in an X-ray imaging apparatus or the like, and includes an electrostatic recording unit including a photoconductive layer that exhibits conductivity when irradiated with radiation. The image information is recorded upon receiving the irradiation of the radiation carrying the image, and the image signal representing the recorded image information is output.

  As the radiation detector, a so-called optical reading type radiation detector that reads using a semiconductor material that generates charges by light irradiation, and charges generated by radiation irradiation are accumulated, and the accumulated charges are thin film transistors ( There is a radiation detector 400 or the like of a method of reading by turning on and off an electrical switch such as a TFT (thin film transistor) (hereinafter referred to as TFT method).

(Configuration of TFT radiation detector 400)
The configuration of the TFT radiation detector 400 will be described. FIG. 1 is a schematic cross-sectional view showing the overall configuration of a TFT radiation detector 400. FIG. 2 shows a configuration of a main part of the TFT type radiation detector 400, and is a diagram showing a glass substrate 408 and each part laminated on the glass substrate 408.

As shown in FIGS. 1 and 2, the TFT radiation detector 400 according to this embodiment includes a photoconductive layer 404 that generates charges when X-rays as an example of radiation carrying image information are incident. It has. As the photoconductive layer 404, amorphous Se, Bi ₁₂ MO ₂₀ (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, etc. are used as a main component, but they have high dark resistance, good photoconductivity against X-ray irradiation, and low temperature by vacuum deposition. An amorphous material capable of forming a large area is preferred.

  For example, an amorphous Se (a-Se) film is used as the amorphous material. A material obtained by doping As, Sb, and Ge into amorphous Se is excellent in thermal stability and is a suitable material for the photoconductive layer 404.

  A bias electrode 401 that applies a bias voltage to the photoconductive layer 404 is formed on the photoconductive layer 404 as an example of a first electrode through which radiation carrying image information is transmitted. The bias electrode 401 is made of, for example, gold (Au) or platinum. The photoconductive layer 404 is irradiated with radiation that has passed through the bias electrode 401.

  As an example of a second electrode that collects the charges generated by the photoconductive layer 404 on the side opposite to the side where the bias electrode 401 is provided with respect to the photoconductive layer 404, that is, below the photoconductive layer 404, a plurality of A charge collection electrode 407a is formed. As shown in FIG. 2, the charge collection electrode 407a is connected to the charge storage capacitor 407c and the switch element 407b, respectively. The charge collection electrode 407a is provided on the glass substrate 408.

  Further, an active matrix layer 407 is constituted by the charge collecting electrode 407a, the switch element 407b, and the charge storage capacitor 407c, and an active matrix substrate 450 is constituted by the glass substrate 408 and the active matrix layer 407 (see FIG. 3).

  As shown in FIG. 2, it is preferable to provide a charge selective transmission layer 402 having charge selective transmission between the photoconductive layer 404 and the bias electrode 401. The charge selective transparency refers to the property of transmitting charges having the opposite polarity to the bias electrode 401 and blocking the transmission of charges having the same polarity as the bias electrode 401.

  As shown in FIG. 2, it is preferable to provide a lower charge selective transmission layer 406 having a polarity opposite to that of the charge selective transmission layer 402 between the photoconductive layer 404 and the charge collection electrode 407a.

  When the bias electrode 401 is a positive electrode, the charge selective transmission layer 402 is configured by a layer (hole injection blocking layer) that blocks holes while being a conductor for electrons, and the bias electrode 401 is In the case of a negative electrode, it is composed of a layer (electron injection blocking layer) that blocks electrons while being a conductor for holes.

  When the charge selective transmission layer 402 is a hole injection blocking layer, an electron injection blocking layer is used for the lower charge selective transmission layer 406, and when the charge selective transmission layer 402 is an electron injection blocking layer, A hole injection blocking layer is used for the lower charge selective transmission layer 406.

  As the hole injection blocking layer, a film in which a hole blocking material is mixed with an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin can be preferably used.

At least one of the hole blocking materials contained in the hole injection blocking layer is preferably at least one selected from carbon clusters or derivatives thereof. Further, the carbon cluster is preferably at least one selected from fullerene C ₆₀ , fullerene C ₇₀ , fullerene oxide or derivatives thereof.

Note that an inorganic material may be used for the lower charge selective transmission layer 406. As the electron injection blocking layer made of an inorganic material, an inorganic material made of a composition such as Sb ₂ S ₃ , ZnTe, CdTe, Sb—Te, Sb—S, As—Se, and As—S compounds can be used. . The layer made of an inorganic material is preferably used by adjusting the carrier selectivity by changing the composition from the stoichiometric composition or by using a multi-component composition with two or more kinds of homologous elements.

As the hole injection blocking layer made of an inorganic material, an inorganic material such as CdS, CeO ₂ , Ta ₂ O ₅ , or SiO is preferably used. The layer made of an inorganic material is preferably used by adjusting the carrier selectivity by changing the composition from the stoichiometric composition or by using a multi-component composition with two or more kinds of homologous elements.

Note that Sb ₂ S ₃ has a strong property of having many localized levels for capturing electrons, and thus has an electron injection blocking property. However, the interface between the Sb ₂ S ₃ layer and the adjacent a-Se layer serves as an electrical barrier. Therefore, it may be used as a hole injection blocking layer.

Further, between the charge selective transmission layer 402 and the photoconductive layer 404, and between the lower charge selective transmission layer 406 and the photoconductive layer 404, as shown in FIG. It may be provided. The crystallization suppression layer 403, 405 GeSe, can be used and _{GeSe 2, Sb 2 Se 3,} a-As 2 Se 3, Se-As, Se-Ge, a Se-Sb-based compounds.

  FIG. 1 schematically shows a radiation detector 400, which includes a bias electrode 401, an active matrix layer 407 including a charge collection electrode 407a, a charge selective transmission layer 402, a lower charge selective transmission layer 406, and crystallization suppression. The layers 403 and 405 are not shown.

  3 is a cross-sectional view showing the structure of one pixel unit of the radiation detector 400, and FIG. 4 is a plan view thereof. The size of one pixel shown in FIGS. 3 and 4 is about 0.05 mm × 0.05 mm to 0.3 mm × 0.3 mm, and this pixel is arranged in a matrix of about 500 × 500 to 6000 × 6000 pixels in the radiation detector as a whole. Has been.

  As shown in FIG. 3, the active matrix substrate 450 includes a glass substrate 408, a gate electrode 411, a charge storage capacitor electrode (hereinafter referred to as Cs electrode) 418, a gate insulating film 413, a drain electrode 412, a channel layer 415, a contact electrode. 416, a source electrode 410, an insulating protective film 417, an interlayer insulating film 420, and a charge collection electrode 407a.

  The gate electrode 411, the gate insulating film 413, the source electrode 410, the drain electrode 412, the channel layer 415, the contact electrode 416, and the like constitute a switch element 407b made of a thin film transistor (TFT), and a Cs electrode 418. Further, a charge storage capacitor 407c is configured by the gate insulating film 413, the drain electrode 412 and the like.

  The glass substrate 408 is a support substrate, and as the glass substrate, an alkali-free glass substrate (for example, # 1737 manufactured by Corning) is preferable. The support substrate is not limited to a glass substrate, and various ceramic substrates, resin substrates, and the like can be used.

  As shown in FIG. 4, the gate electrode 411 and the source electrode 410 are electrode wirings arranged in a lattice pattern, and a switch element 407b made of a thin film transistor is formed at the intersection.

  The switch element 407b source electrode 410 includes a straight line portion as a signal line and an extended portion for constituting the switch element 407b, and the drain electrode 412 connects the switch element 407b and the charge storage capacitor 407c. Is provided.

  The gate insulating film 413 is made of SiNx, SiOx, or the like. The gate insulating film 413 is provided so as to cover the gate electrode 411 and the Cs electrode 418, and a part located on the gate electrode 411 acts as a gate insulating film in the switch element 407b, and a part located on the Cs electrode 418. Acts as a dielectric layer in the charge storage capacitor 407c. That is, the charge storage capacitor 407c is formed by an overlapping region of the Cs electrode 418 and the drain electrode 412 formed in the same layer as the gate electrode 411. The gate insulating film 413 is not limited to SiNx or SiOx, and an anodic oxide film obtained by anodizing the gate electrode 411 and the Cs electrode 418 can be used in combination.

  A channel layer (i layer) 415 is a channel portion of the switch element 407 b and is a current path connecting the source electrode 410 and the drain electrode 412. A contact electrode (n + layer) 416 makes contact between the source electrode 410 and the drain electrode 412.

  The insulating protective film 417 is formed over almost the entire surface (substantially the entire region) on the source electrode 410 and the drain electrode 412, that is, on the glass substrate 408. Thus, the drain electrode 412 and the source electrode 410 are protected, and electrical insulation and separation are achieved. Further, the insulating protective film 417 has a contact hole 421 at a predetermined position thereof, that is, at a portion located on a portion of the drain electrode 412 facing the Cs electrode 418.

  The charge collection electrode 407a is made of an amorphous transparent conductive oxide film. The charge collection electrode 407a is formed so as to fill the contact hole 421, and is stacked on the source electrode 410 and the drain electrode 412. The charge collection electrode 407a and the photoconductive layer 404 are electrically connected to each other so that charges generated in the photoconductive layer 404 can be collected by the charge collection electrode 407a.

  Next, the charge collection electrode 407a will be described in detail. The charge collection electrode 407a used in this embodiment is composed of an amorphous transparent conductive oxide film. Examples of amorphous transparent conductive oxide film materials include oxides of indium and tin (ITO: Indium-Tin-Oxide), oxides of indium and zinc (IZO: Indium-Zinc-Oxide), indium and germanium. An oxide (IGO: Indium-Germanium-Oxide) or the like having a basic composition can be used.

  As the charge collection electrode 407a, various metal films and conductive oxide films are used, and transparent conductive oxide films such as ITO (Indium-Tin-Oxide) are often used for the following reasons. When the incident X-ray dose is large in the radiation detector 400, unnecessary charges may be trapped in the semiconductor film (or in the vicinity of the interface between the semiconductor film and an adjacent layer).

  Since such residual charges are stored for a long time or move while taking time, the X-ray detection characteristics are deteriorated during the subsequent image detection, and an afterimage (virtual image) appears. Therefore, in Japanese Patent Laid-Open No. 9-9153 (corresponding US Pat. No. 5,563,421), when residual charges are generated in the photoconductive layer 404, the residual charges are reduced by irradiating light from the outside of the photoconductive layer 404. A method of removing by excitation is disclosed. JP-A-2004-146769 (corresponding US Pat. Nos. 6,995,375 and 7034312) discloses radiation in which sensitivity fluctuations are eliminated by stabilizing an electric field generated in a radiation detector provided with divided electrodes by light irradiation. A detector is disclosed. In this case, in order to irradiate light efficiently from the lower side of the photoconductive layer 404 (on the side of the charge collection electrode 407a), the charge collection electrode 407a needs to be transparent to the irradiation light.

  In addition, for the purpose of increasing the area filling factor (fill factor) of the charge collection electrode 407a, or for the purpose of shielding the switch element 407b, or for the purpose of preventing the TFT from being destroyed during high-dose irradiation by functioning as a top gate, It is desired to form the charge collection electrode 407a so as to cover the element 407b. However, if the charge collection electrode 407a is opaque, the switch element 407b cannot be observed after the charge collection electrode 407a is formed.

  For example, when the characteristic inspection of the switch element 407b is performed after the charge collection electrode 407a is formed, if the switch element 407b is covered with the opaque charge collection electrode 407a, the cause of the characteristic failure of the switch element 407b is found. Cannot be observed with an optical microscope. Therefore, it is desirable that the charge collection electrode 407a be transparent so that the switch element 407b can be easily observed even after the charge collection electrode 407a is formed.

  The interlayer insulating film 420 is made of a photosensitive acrylic resin, and serves to electrically isolate the switch element 407b. A contact hole 421 passes through the interlayer insulating film 420, and the charge collection electrode 407 a is connected to the drain electrode 412. The contact hole 421 is formed in a reverse taper shape as shown in FIG. A high voltage power supply (not shown) is connected between the bias electrode 401 and the Cs electrode 418.

  As shown in FIG. 1, a protective member 442 is provided on the glass substrate 408. The protection member 442 surrounds the periphery of the photoconductive layer 404 and is formed in a frame shape constituted by four sides (four straight lines).

  A sealing layer 444 that covers the photoconductive layer 404 and the bias electrode 401 and seals the photoconductive layer 404 and the bias electrode 401 is formed in the space on the inner peripheral side of the protective member 442. In the present embodiment, the protective member 442 and the sealing layer 444 constitute a sealing member that seals the photoconductive layer 404 and the bias electrode 401.

  As the material of the sealing layer 444, a material having X-ray transparency, insulation, and moisture resistance is selected. Specifically, room temperature curable resins such as epoxy resins and silicon resins are used. Further, as the sealing member for the photoconductive layer 404 and the bias electrode 401, a protective film that covers the photoconductive layer 404 and the bias electrode 401 may be used. For this protective film, a material having X-ray permeability, insulation and moisture resistance is selected, and for example, a PET film is used. Note that the protective film may be provided instead of the sealing layer 444 or may be provided over the sealing layer 444. Further, the protective film may be formed so as to cover the protective member 442.

  Further, the protective member 442 is made of an insulating member having an insulating property. As the insulating member, for example, polycarbonate, polyethylene terephthalate (PET), polymethyl methacrylate (acrylic), polyvinyl chloride, glass or the like is used.

  Note that the sealing member may include only the sealing layer 444 without the protective member 442.

(Operation principle of TFT radiation detector)
Next, the operation principle of the above-described TFT radiation detector 400 will be described.
When the photoconductive layer 404 is irradiated with X-rays, charges (electron-hole pairs) are generated in the photoconductive layer 404. In a state where a voltage is applied between the bias electrode 401 and the Cs electrode 418, that is, in a state where a voltage is applied to the photoconductive layer 404 via the bias electrode 401 and the Cs electrode 418, charge accumulation with the photoconductive layer 404 is performed. Since the capacitor 407c is electrically connected in series, the electrons generated in the photoconductive layer 404 move to the + electrode side, and the holes move to the-electrode side. As a result, the charge storage capacitor Charge is accumulated in 407c.

  The charge stored in the charge storage capacitor 407c can be taken out through the source electrode 410 by turning on the switch element 407b by an input signal to the gate electrode 411. Since the electrode wiring composed of the gate electrode 411 and the source electrode 410, the switch element 407b, and the charge storage capacitor 407c are all provided in a matrix, signals input to the gate electrode 411 are sequentially scanned to obtain the source electrode 410. By detecting the signal from each source electrode 410, X-ray image information can be obtained two-dimensionally.

(Configuration of radiation imaging apparatus 100)
Next, the configuration of the radiation imaging apparatus 100 will be described.

  The radiation imaging apparatus 100 includes a housing 102 that houses each component. A partition wall 104 that partitions a space in the housing 102 is provided in the housing 102, and the interior of the housing 102 is divided into two spaces. As a result, a first casing 111 in which one of the two divided spaces is formed and a second casing 112 in which the other of the two spaces is formed are configured. Is done. The first housing 111 is sealed against the outside air, and the internal space of the second housing 112 and the internal space of the first housing 111 are separated.

  The housing 102 and the partition wall 104 are formed of, for example, a SUS plate (stainless steel plate). In the present embodiment, the first casing 111 and the second casing 112 are integrally formed, but the first casing 111 and the second casing 112 may be formed separately. .

  The first casing 111 is provided with a carbon plate 106 on the surface irradiated with radiation. Between the carbon plate 106 and the sealing layer 444 of the radiation detector 400, a cushioning material 108 for reducing the impact between the radiation detector 400 and the carbon plate 106 is provided.

  On the partition 104 side of the active matrix substrate 450 of the radiation detector 400, a light guide plate 110 is provided. As the light guide plate 110, for example, an acrylic plate is used.

  A light source 113 is provided at an end of the light guide plate 110, and light from the light source 113 is irradiated to the active matrix substrate 450 through the light guide plate 110. As the light source 113, for example, an LED is used.

  Light irradiation through the light guide plate 470 accumulates charges in advance in the space between the charge collection electrodes 407a (region where there is no electrode), so that the charge generated by the incidence of radiation moves to the space between the charge collection electrodes 407a. This is used to prevent sensitivity fluctuations. Further, light irradiation through the light guide plate 470 may be used to excite and remove residual charges remaining in the photoconductive layer 404.

  Between the partition wall 104 and the light guide plate 110, a heat insulating member 116 that blocks heat from the partition wall 104 side is provided. The light guide plate 110 may be used as a heat insulating member without providing the heat insulating member 116. As the heat insulating member 116, for example, a sponge formed by foaming synthetic resin is used.

  The data lines 120 are electrically connected to the source electrode 410 of the radiation detector 400, respectively. Each data wiring 120 is connected to a signal processing board 122.

  Gate wirings 123 are electrically connected to the gate electrode 411 of the radiation detector 400, respectively. Each gate line 123 is connected to a gate line driver 126.

  The data wiring 120 and the gate wiring 123 are constituted by flexible cables, and are fixed to a partition wall 104 that forms part of the first casing 111 and the second casing 112.

  The switch element 407b is turned on by a signal input from the gate line driver 126 to the gate electrode 411 through the gate wiring 123.

  The charge stored in the charge storage capacitor 407c is transmitted as a charge signal through the source electrode 410 and the data wiring 120 and input to the signal processing board 122.

  The signal processing board 122 includes a signal amplification circuit 124 and a sample hold circuit 125 provided for each data wiring 120, and an electric signal transmitted through each data wiring 120 is transmitted by the signal amplification circuit 124. After being amplified, it is held in the sample hold circuit 125.

  Further, on the output side of the sample hold circuit 125, a multiplexer (not shown) and an A / D converter (not shown) as an example of an electric signal conversion unit for converting an electric signal carrying image information are sequentially provided. It is connected. The charge signals held in the individual sample and hold circuits 125 are sequentially input to the multiplexer (serially), and the analog electric signal is converted into a digital electric signal by the A / D converter.

  In addition, a circuit board 128 having a power supply circuit 129 that generates output power required from input power is provided, and the radiation detector 400 and the power supply circuit 129 transform the direct current from the power supply to a desired voltage. Supply to various circuits and elements.

  In the present embodiment, a signal amplification circuit 124, a signal processing board 122, a circuit board 128 having a power supply circuit 129, a gate line driver 126, a power supply circuit 129, and a cooling fan 142 described later are provided in the second casing 112 as heat sources. Has been placed. Note that not all of the plurality of heat generation sources need be arranged in the second housing 112, and at least one of the plurality of heat generation sources may be arranged.

  As shown in FIG. 6, a partition wall 105 is provided on the radiation detector 400 side (upper side in FIG. 6) of the light source 113 and an opening 107 is formed in the partition wall 104, so that the space including the light source 113 is the second housing. When the light source 113 can be regarded as the internal space of 112, the light source 113 can be regarded as a heat source disposed in the second housing 112.

  The second housing 112 is provided with a heat radiating member 140 that dissipates the heat of the signal amplification circuit 124.

  The heat dissipation member 140 is in contact with the signal amplification circuit 124 and absorbs heat from the signal amplification circuit 124. Further, the heat radiating member 140 is not in contact with the second housing 112 and dissipates the absorbed heat into the second housing 112.

  The configuration in which the heat radiating member 140 is not in contact with the second housing 112 is a configuration in which the heat of the heat radiating member 140 is not transmitted to the second housing 112. A structure in which the heat radiating member 140 is fixed to the inner wall of the second housing 112 through a heat insulating material such as resin is conceivable.

  Further, the heat radiating member 140 may be provided in the signal amplification circuit 124 via a heat conducting member that conducts heat.

  Further, as shown in FIG. 7, the heat dissipation member 141 may be provided for the signal processing board 122, the circuit board 128 having the power supply circuit 129, and the gate line driver 126.

  Further, the heat radiating member 140 may be configured to contact the second housing 112. In this configuration, the heat of the heat radiating member 140 is released outside the second housing 112 through the second housing 112.

  The heat radiating member 140 is made of a material having better thermal conductivity than the signal amplification circuit 124 that is a heat source provided with the heat radiating member 140. When the signal amplification circuit 124 is formed of an IC chip whose exterior is made of plastic or the like, the heat radiating member 140 is a metal plate such as aluminum, for example.

  As an example of a cooling unit that circulates a cooling fluid in the second casing and cools the second casing, the second casing 112 cools the second casing by circulating outside air in the second casing 112. A cooling fan 142 is provided. Further, the second casing 112 is formed with a plurality of inlets 144 through which outside air as cooling fluid flows, and outlets 146 through which the outside air flowing into the second casing 112 is discharged.

  The cooling fan 142 is driven to allow the outside air outside the second housing 112 to flow into the second housing 112 from the inlet 144, and the outside air that has flowed in is discharged outside the second housing 112 from the discharge port 146. .

  The cooling fluid circulated by the cooling means is not limited to air, and may be a liquid such as gas or water.

  The signal processing board 122, the circuit board 128 including the power supply circuit 129, and the gate line driver 126 are formed as an integrated board, and a spacer 130 is provided between the board and the partition wall 104. The spacer 130 functions as a heat transfer member that transfers heat generated by the signal processing board 122, the circuit board 128 including the power supply circuit 129, and the gate line driver 126 to the second casing 112 (partition wall 104).

  A gap is formed between the signal processing board 122, the circuit board 128 including the power supply circuit 129, and the gate line driver 126 with the inner wall (partition wall 104) of the second casing 112 by the spacer 130. The outside air that has flowed into 112 flows through this gap. Thereby, the heat of the signal processing board 122, the circuit board 128 having the power supply circuit 129 and the gate line driver 126 itself, and the heat transmitted to the second casing 112 (partition wall 104) can be efficiently cooled.

  The spacer 130 may be formed of a heat insulating member when attention is paid to heat insulation with respect to the radiation detector 400.

(Operation of this embodiment)
Next, the operation of the above embodiment will be described.

  According to this configuration, the signal amplification circuit 124 as a heat generation source, the signal processing board 122, the circuit board 128 having the power supply circuit 129, the gate line driver 126, the power supply circuit 129, and the cooling fan 142 described later are included in the second casing 112. And is isolated from the radiation detector 400.

  Further, the heat of the signal amplification circuit 124 that generates a particularly large amount of heat is dissipated into the second housing 112 by the heat dissipation member 140. The heat dissipated in the second housing 112 is cooled as the cooling fan 142 circulates outside air in the second housing 112.

  Therefore, the heat radiation efficiency for radiating the heat of the heat source is good, and the influence of the heat of the heat source on the radiation detector 400 can be effectively reduced.

  In addition, since the heat insulating member 116 is provided between the first housing 111 and the second housing 112, heat is generated from the heat source in the second housing 112 to the radiation detector 400 of the first housing 111. It is difficult to transmit, and the influence of the heat of the heat source on the radiation detector 400 can be effectively reduced.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

FIG. 1 is a schematic cross-sectional view showing the configuration of a TFT radiation detector. FIG. 2 is a schematic configuration diagram showing a main part of a TFT radiation detector. FIG. 3 is a cross-sectional view showing the structure of one pixel unit of a TFT radiation detector. FIG. 4 is a plan view showing the structure of one pixel unit of a TFT radiation detector. FIG. 5 is a schematic cross-sectional view showing the configuration of the radiation imaging apparatus. FIG. 6 is a schematic cross-sectional view showing a configuration in which the light source is a heat source arranged in the second housing. FIG. 7 is a schematic cross-sectional view showing an example in which a heat dissipation member is provided in a plurality of heat generation sources.

Explanation of symbols

100 Radiography system
111 First housing
112 Second housing
113 Light source (heat source)
116 Thermal insulation
120 Data wiring (flexible cable)
122 Signal processing board (heat source)
123 Gate wiring (flexible cable)
124 Signal amplification circuit (heat source)
126 Gate line driver (switching element driver, heat source)
128 Circuit board (heat source)
129 Power circuit (heat source)
140 Heat dissipation member
141 Heat dissipation member
142 Cooling fan (cooling means, heat source)
400 radiation detector

Claims (7)

A first housing in which a radiation detector for detecting radiation is housed;
A second housing in which a heat source is housed;
A heat dissipating member provided in the second casing and dissipating heat of the heat source in contact with the heat source;
A radiography apparatus comprising:   The radiation imaging apparatus according to claim 1, further comprising a cooling unit that circulates a cooling fluid in the second housing to cool the inside of the second housing.   The radiation imaging apparatus according to claim 2, wherein the heat radiating member is not in contact with the second housing and dissipates heat of the heat generation source in the second housing.   The radiation imaging apparatus according to claim 1, wherein a heat insulating member is provided between the first housing and the second housing.   The heat source includes a signal amplification circuit that amplifies an electrical signal from the radiation detector, a signal processing board that processes an electrical signal from the radiation detector, a power supply circuit that supplies power to the radiation detector, and the radiation The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a switching element driver that inputs a signal to a switching element for reading out the electric charges converted from.   The radiation imaging apparatus according to claim 5, wherein the heat dissipation member is disposed in the signal amplification circuit.   The flexible cable which transmits the electric signal from the said radiation detector to the circuit in the said 2nd housing | casing is being fixed to at least one by the said 1st housing | casing and the said 2nd housing | casing. The radiation imaging apparatus according to item 1.

Images