WO2012029384A1

WO2012029384A1 - Radiation imaging device

Info

Publication number: WO2012029384A1
Application number: PCT/JP2011/064397
Authority: WO
Inventors: 西納直行; 中津川晴康; 大田恭義; 岩切直人
Original assignee: 富士フイルム株式会社
Priority date: 2010-08-31
Filing date: 2011-06-23
Publication date: 2012-03-08
Also published as: JP2012050596A

Abstract

A radiation imaging device (20) has: contact mechanisms (118, 190, 214, 220, 240, 254, 274), which bring a scintillator (150) and a radiation conversion panel (64) into contact with each other; move detecting units (56, 58), which detect move of the radiation imaging device (20); and a contact control unit (110), which controls the contact mechanisms (118, 190, 214, 220, 240, 254, 274) so as to bring the scintillator (150) and the radiation conversion panel (64) into contact with each other when radiation (16) is applied to at least a radiation detector (66), and which stops the control of the contact made between the scintillator (150) and the radiation conversion panel (64) by the contact mechanisms (118, 190, 214, 220, 240, 254, 274) when physical quantities relating to the move of the radiation imaging device (20), said physical quantities having been detected by the move detecting units (56, 58), exceed a predetermined threshold.

Description

Radiography equipment

The present invention relates to a radiation imaging apparatus having a scintillator that converts radiation into visible light and a radiation conversion panel that converts the visible light into an electrical signal.

In the medical field, a radiation image of a subject is widely acquired by irradiating the subject with radiation from a radiation source and detecting the radiation transmitted through the subject with a radiation imaging apparatus. In this case, the radiation imaging apparatus includes, for example, an indirect conversion type radiation detector including a scintillator that converts radiation transmitted through a subject into visible light and a radiation conversion panel that converts the visible light into an electrical signal.

In recent years, a radiation detector has been proposed in which a scintillator including a columnar crystal such as CsI formed in a direction substantially orthogonal to a highly rigid support substrate is disposed on the support substrate (Japanese Patent Laid-Open No. 2006-58124). reference). In this case, the radiation detector is configured by bonding a tip portion of the columnar crystal disposed on the support substrate and a radiation conversion panel.

Here, when the columnar crystal converts radiation into visible light, the visible light travels through the columnar portion of the columnar crystal and reaches the radiation conversion panel from the tip portion of the columnar crystal. As a result, the incident visible light can be converted into an electric signal in the radiation conversion panel.

In addition, in order to prevent a reduction in the amount of visible light emission in the columnar crystals and to avoid occurrence of crosstalk due to visible light by ensuring a certain gap between the columns, the filling rate of the columnar crystals is predetermined. It is desirable that the filling rate is set to (for example, 70% to 85%). By doing so, scattering of visible light converted from radiation in the scintillator is suppressed, and occurrence of blurring of the radiation image can be avoided.

As described above, the support substrate of the scintillator needs to have a certain weight in order to ensure high rigidity. Further, both surfaces of the scintillator (the tip portion of the columnar crystal and the base end portion on the support substrate side of the columnar crystal) are fixed by the support substrate and the radiation conversion panel, respectively. In this case, the rigidity may be different between the support substrate and the radiation conversion panel. Further, with respect to the columnar crystal of the scintillator, it is necessary to secure a certain gap in the columnar portion in order to prevent crosstalk.

As a result, for example, if a doctor or a radiographer accidentally drops the radiation imaging apparatus during transportation of the radiation imaging apparatus and gives an impact to the radiation imaging apparatus from the outside, the distortion amount of the support substrate and the radiation conversion panel Due to the difference from the strain amount, careless stress acts on the columnar crystals. As a result, cracks (cracks) and cracks of the columnar crystals occur, which may cause deterioration in performance of the radiographic apparatus such as blurring of radiographic images.

An object of the present invention is to appropriately protect the scintillator against an external impact.

To achieve the above object, the present invention is a radiographic apparatus having a scintillator that converts radiation into visible light, and a radiation detector that includes a radiation conversion panel that converts the visible light into an electrical signal,
A contact mechanism for contacting the scintillator and the radiation conversion panel;
A movement detector for detecting movement of the radiation imaging apparatus;
At least when the radiation detector is irradiated with the radiation, the contact mechanism is controlled to bring the scintillator and the radiation conversion panel into contact with each other, and on the other hand, the movement of the radiation imaging apparatus detected by the movement detection unit is involved. It further has a contact control unit that stops contact control between the scintillator and the radiation conversion panel by the contact mechanism when the physical quantity exceeds a predetermined threshold value.

In this case, the scintillator is configured by vapor-depositing a columnar crystal capable of converting the radiation into the visible light on a support substrate that supports the scintillator, along a direction substantially orthogonal to the support substrate. The contact mechanism controls contact between the tip portion of the columnar crystal and the radiation conversion panel.

Further, in the case where the radiation detector, the contact mechanism, the movement detection unit, and the contact control unit are housed in a portable housing that can transmit the radiation, the thickness direction of the housing is within the housing. The support substrate, the scintillator, and the radiation conversion panel are arranged in order, and the surface of the housing that faces the support substrate or the radiation conversion panel is an irradiation surface on which the radiation is irradiated.

Further, the movement detection unit is an acceleration sensor that detects an acceleration of the radiation imaging apparatus, or a pressure sensor that detects a pressure applied to the radiation imaging apparatus from a subject in contact with the irradiation surface, and the contact control unit is When the physical quantity related to the acceleration or the pressure is less than the threshold value, the tip portion of the columnar crystal and the radiation conversion panel are brought into contact by controlling the contact mechanism, while the physical quantity is When exceeding the threshold value, it is desirable to stop contact control between the tip portion of the columnar crystal and the radiation conversion panel by the contact mechanism.

The contact mechanism preferably has any one of the following [1] to [5].

[1] The contact mechanism is an airbag that controls contact between the tip portion of the columnar crystal and the radiation conversion panel by expanding or contracting along the thickness direction of the casing, and the radiation imaging apparatus Is further provided with an inflator that is housed in the casing and inflates the airbag in the thickness direction by feeding an inert gas into the airbag.

In this case, in a plan view, the scintillator is formed inside the support substrate and the radiation conversion panel, and the air bag surrounds the scintillator so as to surround the scintillator or the radiation conversion. The inflator is disposed on an outer edge of the panel, and when the contact control unit instructs to separate the tip portion of the columnar crystal from the radiation conversion panel, the inflator sends the inert gas into the airbag, The airbag expands in the thickness direction between the outer edge portion of the support substrate and the outer edge portion of the radiation conversion panel, thereby separating the tip portion of the columnar crystal from the radiation conversion panel.

The airbag is interposed between the support substrate and a surface of the housing facing the support substrate, or a surface of the radiation conversion panel and the housing facing the radiation conversion panel. When the contact control unit instructs to stop contact control between the tip portion of the columnar crystal and the radiation conversion panel, the airbag discharges the inert gas and By contracting in the thickness direction, the end portion of the columnar crystal is separated from the radiation conversion panel.

[2] The contact mechanism makes the chamber containing the radiation detector in a negative pressure state and contracts along the thickness direction, thereby bringing the tip of the columnar crystal into contact with the radiation conversion panel, On the other hand, it is an accommodation bag that separates the end portion of the columnar crystal and the radiation conversion panel by inflating the chamber along the thickness direction under atmospheric pressure.

The radiation imaging apparatus further includes a leak valve disposed in a passage communicating with the containing bag, and the contact control unit instructs the contact between the tip portion of the columnar crystal and the radiation conversion panel In addition, the storage bag puts the chamber in a negative pressure state, and the leak valve is in a valve closed state, thereby preventing air from entering the chamber through the passage, When the contact control unit instructs to stop the contact control between the tip portion of the columnar crystal and the radiation conversion panel, the leak valve enters the chamber through the passage when the leak valve is opened. To enter an atmospheric pressure state.

[3] The contact mechanism contracts along the thickness direction to bring the tip portion of the columnar crystal into contact with the radiation conversion panel, while extending along the thickness direction, It is a spring member that performs contact control between the tip portion of the columnar crystal and the radiation conversion panel.

In this case, the spring member is disposed between the top plate and the bottom plate on the irradiation surface side in the housing and is disposed at a location near the radiation detector, or an outer edge of the radiation conversion panel. And the outer edge of the support substrate.

One end of the spring member is fixed to the outer edge of the top plate or the radiation conversion panel, and the other end of the spring member is disposed on the outer edge of the bottom plate or the support substrate. When the contact controller is fixed to the lock member and the contact control unit instructs the contact between the tip portion of the columnar crystal and the radiation conversion panel, the lock member contracts the spring member in the thickness direction, When the contact control unit instructs to stop contact control between the tip portion of the columnar crystal and the radiation conversion panel, the lock member releases the locked state with respect to the spring member, and the spring member is moved to the thickness. Stretch in the direction.

[4] The contact mechanism contracts along the thickness direction to bring the tip portion of the columnar crystal into contact with the radiation conversion panel, while extending along the thickness direction, The piezoelectric element stops contact control between the columnar crystal tip and the radiation conversion panel.

In this case, the piezoelectric element is disposed between the top plate and the bottom plate on the irradiation surface side in the housing and in the vicinity of the radiation detector, or the radiation conversion panel. Between the outer edge of the support substrate and the outer edge of the support substrate.

[5] The contact mechanism is a cam that performs contact control between the tip portion of the columnar crystal and the radiation conversion panel by rotating about a rotation axis.

In each of the above-described inventions, the contact control unit sets the contact mechanism so that the scintillator and the radiation conversion panel are brought into contact with each other when the radiation source that outputs the radiation prepares to irradiate the radiation. You may control.

Further, the contact control unit brings the scintillator and the radiation conversion panel into contact with each other before irradiation of the radiation to the radiation detector via the subject based on order information related to radiation irradiation on the subject. The contact mechanism may be controlled as described above, and the contact mechanism may be controlled to stop contact control between the scintillator and the radiation conversion panel after the radiation irradiation.

As described above, according to the present invention, at least when the radiation detector is irradiated with radiation, the scintillator and the radiation conversion panel are in contact with each other, while the physical quantity related to the movement of the radiation imaging apparatus detected by the movement detection unit is When the predetermined threshold is exceeded, contact control between the scintillator and the radiation conversion panel by the contact mechanism stops, so that the scintillator is appropriately protected from the impact even when an impact is applied to the radiation imaging apparatus from the outside. can do.

Therefore, even when the scintillator is composed of, for example, a columnar crystal, it is possible to reliably avoid the occurrence of cracks (cracks) and cracks of the columnar crystal due to the impact.

It is a block diagram of the radiography system using the radiography apparatus (electronic cassette) which concerns on this embodiment. It is a perspective view of the electronic cassette shown in FIG. 3A and 3B are III-III sectional views of the electronic cassette shown in FIG. 4A and 4B are cross-sectional views of the main part in the vicinity of the radiation detector in the electronic cassette of FIG. 5 is a schematic plan view of the radiation detector of FIGS. 4A and 4B. FIG. 6A and 6B are cross-sectional views of main parts in the vicinity of the radiation detector in the electronic cassette of FIG. It is an electrical schematic block diagram of the electronic cassette of FIG. It is a flowchart which shows operation | movement of the radiography system of FIG. It is a flowchart which shows operation | movement of the radiography system of FIG. 1 in the case where an external impact is applied to the cassette of FIG. FIG. 10A and FIG. 10B are main part sectional views showing a first modification of the present embodiment. FIG. 11A and FIG. 11B are main part sectional views showing a second modification of the present embodiment. 12A and 12B are main part cross-sectional views showing a third modification of the present embodiment. FIG. 13A and FIG. 13B are cross-sectional views of relevant parts showing a fourth modification of the present embodiment. FIG. 14A and FIG. 14B are main part sectional views showing a fifth modification of the present embodiment. FIG. 15A and FIG. 15B are cross-sectional views of relevant parts showing a sixth modification of the present embodiment. FIG. 16A and FIG. 16B are main part sectional views showing a seventh modification of the present embodiment. FIG. 17A is a schematic explanatory view schematically showing the internal configuration of a cassette of the eighth modification example of the present embodiment, and FIG. 17B is a schematic explanatory view schematically showing an example of the scintillator of FIG. 17A.

A preferred embodiment of the radiation imaging apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 17B.

[Configuration of this embodiment]
FIG. 1 is a configuration diagram of a radiation imaging system 10 having an electronic cassette 20 (radiation imaging apparatus) according to the present embodiment.

The radiation imaging system 10 detects a radiation output device 18 that irradiates a subject 16 such as a patient lying on an imaging table 12 such as a bed, and the radiation 16 that has passed through the subject 14 and converts the radiation 16 into a radiation image. The electronic cassette 20 includes a console 22 that controls the entire radiation imaging system 10 and receives an input operation of a doctor or a radiographer (hereinafter also referred to as a doctor), and a display device 24 that displays a captured radiation image or the like. .

Between the radiation output device 18, the electronic cassette 20, the console 22 and the display device 24, for example, UWB (Ultra Wide Band), IEEE 802.11. Signals are transmitted and received by wireless LAN such as a / b / g / n or wireless communication using millimeter waves or the like. It goes without saying that signals may be transmitted and received by wired communication using a cable.

The console 22 is connected to a radiology information system (RIS) 26 that centrally manages radiographic images and other information handled in the radiology department in the hospital. The RIS 26 is used to comprehensively manage medical information in the hospital. A medical information system (HIS) 28 to be managed is connected.

The radiation output device 18 includes a radiation source 30 that irradiates the radiation 16, a radiation control device 32 that controls the radiation source 30, and a radiation switch 34. The radiation source 30 irradiates the electronic cassette 20 with radiation 16. The radiation 16 irradiated by the radiation source 30 may be X-rays, α-rays, β-rays, γ-rays, electron beams, or the like. The radiation switch 34 is configured to have a two-stage stroke, and the radiation control device 32 prepares for irradiation of the radiation 16 when the radiation switch 34 is half-pressed by the doctor and from the radiation source 30 when the radiation switch 34 is fully pressed. Irradiate.

As described above, the radiation output device 18, the electronic cassette 20, the console 22, and the display device 24 can transmit and receive signals. Therefore, in the radiation output device 18, the radiation switch 34 is half pressed. Sometimes, a signal indicating preparation for irradiation may be transmitted to the console 22 or the like, and then a signal indicating the start of irradiation of the radiation 16 may be transmitted to the console 22 or the like when the radiation switch 34 is fully pressed.

2 is a perspective view of the electronic cassette 20 shown in FIG. 1, and FIGS. 3A and 3B are cross-sectional views taken along line III-III of the electronic cassette 20 shown in FIG.

The electronic cassette 20 includes a panel unit 42 and a control unit 48 disposed on the panel unit 42. The thickness of the panel unit 42 is set to be thinner than the thickness of the control unit 48.

The panel unit 42 includes a substantially rectangular housing 40 made of a material that is transmissive to the radiation 16, and the radiation 16 is irradiated onto the irradiation surface 44 that is the surface (upper surface) of the panel unit 42. A guide line 50 indicating the shooting area and shooting position of the subject 14 is formed at a substantially central portion of the irradiation surface 44. The outer frame of the guide line 50 becomes a shootable region 52 indicating the irradiation field of the radiation 16. The center position of the guide line 50 (intersection where the guide line 50 intersects in a cross shape) is the center position of the shootable area 52.

A handle 54 that can be grasped by a doctor is disposed on the side surface of the housing 40 on the control unit 48 side. The doctor can transport the electronic cassette 20 to a desired location (for example, the imaging table 12) by holding the handle 54. Therefore, the electronic cassette 20 is a portable radiation imaging apparatus.

In the vicinity of the handle 54 in the housing 40, a three-axis acceleration sensor 56 (movement detector) for detecting the acceleration (three-axis component) of the electronic cassette 20 is disposed. The acceleration sensor 56 is disposed in the vicinity of the handle 54 as described above so that when the electronic cassette 20 is accidentally dropped, the acceleration sensor 56 is not broken by a drop impact. In addition, a triaxial pressure sensor 58 (movement detector) that detects pressure (three axial components) applied to the electronic cassette 20 from the outside is disposed near the center position of the guide wire 50 in the housing 40. ing. In this case, since the acceleration is generated by the movement of the electronic cassette 20, and the electronic cassette 20 may be displaced when the electronic cassette 20 receives pressure, these physical quantities are both electronic This is a physical quantity related to the movement of the cassette 20.

Further, a radiation detector 66 having a scintillator panel 62 and a radiation conversion panel 64 and a drive circuit unit 68 (see FIG. 7) for driving the radiation conversion panel 64 are further arranged inside the housing 40.

The scintillator panel 62 includes a scintillator 150 (see FIGS. 4A and 4B) that converts the radiation 16 transmitted through the subject 14 into fluorescence included in the visible light region. The radiation conversion panel 64 is an indirect conversion type radiation conversion panel that can transmit the radiation 16 and converts the fluorescence converted by the scintillator 150 into an electric signal.

FIG. 3A shows an ISS (Irradiation Side Sampling) type radiation detector as a surface reading method in which a radiation conversion panel 64 and a scintillator panel 62 are arranged in the housing 40 in order from the irradiation surface 44 irradiated with the radiation 16. 66 is illustrated. On the other hand, FIG. 3B shows a PSS (Penetration Side Sampling) type radiation as a back side reading method in which a scintillator panel 62 and a radiation conversion panel 64 are arranged in the housing 40 in order from the irradiation surface 44 irradiated with the radiation 16. A detector 66 is illustrated.

The control unit 48 has a substantially rectangular casing 108 made of a material that is impermeable to the radiation 16. The housing 108 extends along one end of the irradiation surface 44, and the control unit 48 is disposed outside the imageable region 52 on the irradiation surface 44. In this case, inside the housing 108, a cassette control unit 110 (contact control unit) that controls a panel unit 42 (to be described later), a memory 112 as a buffer memory that stores image data of a captured radiographic image, and the console 22. A communication unit 114 capable of wirelessly transmitting and receiving signals and a power source unit 116 such as a battery are arranged (see FIG. 7). The power supply unit 116 supplies power to each unit in the electronic cassette 20.

In addition, on the upper surface of the housing 108, a captured radiographic image or the like can be displayed, while a touch-panel display operation unit 122 that allows a doctor to input various information and various notifications to the doctor as sounds. An output speaker 124 is disposed. Further, on the side surface of the housing 108, information can be transmitted and received between the input terminal 126 of the AC adapter for charging the power supply unit 116 from the external power source and the external device (for example, the console 22). A USB terminal 128 is provided as an interface means.

4A and 4B are cross-sectional views of the main part of the radiation detector 66 inside the housing 40. As an example, the ISS radiation detector 66 of FIG. 3A is illustrated. In this case, the radiation detector 66 is disposed between the top plate 132 on the irradiation surface 44 side and the bottom plate 140 on the bottom surface side in the housing 40.

Specifically, a buffer material 138 such as a sponge is bonded to the bottom plate 140 via an adhesive layer 136, and the scintillator panel 62 is bonded to the buffer material 138 via an adhesive layer 142. On the other hand, the radiation conversion panel 64 is bonded to the bottom plate 140 side of the top plate 132 through the adhesive layer 130.

The scintillator panel 62 includes a support substrate 144 having rigidity such as an Al substrate bonded to the buffer material 138 through an adhesive layer 142, and a scintillator 150 formed by vapor deposition on the upper surface of the support substrate 144.

The scintillator 150 is obtained by forming, for example, cesium iodide (CsI: Tl) added with thallium into a strip-like columnar crystal structure 148 on a support substrate 144 by a vacuum deposition method. The base end portion of the scintillator 150 is a non-columnar crystal portion 146. In this case, the columnar crystal structure 148 is formed in a state in which a certain gap is secured between the columns along a direction substantially perpendicular to the support substrate 144 (the vertical direction in FIGS. 4A and 4B). Further, the CsI scintillator 150 has a characteristic that the columnar crystal structure 148 is weak against humidity and the non-columnar crystal portion 146 is particularly vulnerable to humidity.

The scintillator 150 (the moisture-proof protective material 152 that covers the columnar crystal structure 148) and the radiation conversion panel 64 are pressed against each other, so that the scintillator 150 and the radiation conversion panel 64 in the housing 40 are pressed against each other. The relative position is fixed. Thus, when the radiation 16 passes through the radiation conversion panel 64 and the moisture-proof protective material 152 and reaches the scintillator 150, the columnar crystal structure 148 converts the radiation 16 into fluorescence in the visible light region, and the converted fluorescence is columnar. The columnar portion of the crystal structure 148 travels and reaches the radiation conversion panel 64 from the tip portion of the columnar crystal structure 148 through the moisture-proof protective material 152. Therefore, in the radiation conversion panel 64, the incident fluorescence can be converted into an electrical signal. The radiation conversion panel 64 is obtained by stacking pixels (photoelectric conversion elements) that convert the fluorescence into electric signals on a TFT substrate.

Incidentally, since the columnar crystal structure 148 has hard and brittle characteristics, it is vulnerable to external pressure and stress. Therefore, when the electronic cassette 20 is dropped or excessive pressure is applied from the outside, the columnar crystal structure 148 is cracked (broken) or cracked. As a result, the imaging performance and sensitivity are lowered, and radiation is reduced. There is a risk of performance degradation of the electronic cassette 20 such as image blurring.

More specifically, the support substrate 144 of the scintillator 150 needs to have a certain weight in order to ensure high rigidity. In addition, the rigidity may be different between the support substrate 144 and the radiation conversion panel 64. Further, the columnar crystal structure 148 of the scintillator 150 also has a certain gap (for example, 70% to 70%) between the columns in order to avoid a decrease in the amount of fluorescent light emission and the occurrence of fluorescence crosstalk between the columns. It is necessary to ensure a filling rate of 85%.

As a result, for example, if a doctor accidentally drops the electronic cassette 20 during transportation of the electronic cassette 20 and applies an impact to the electronic cassette 20 from the outside, the distortion amount and radiation conversion of the support substrate 144 having different rigidity Inadvertent stress acts on the columnar crystal structure 148 due to a difference from the strain amount of the panel 64, and therefore the columnar crystal structure 148 is cracked (broken) or cracked. There is a risk of performance deterioration of the electronic cassette 20. Further, even if the support substrate 144 and the radiation conversion panel 64 have the same rigidity, there may be cases where the amounts of distortion differ from each other depending on the manner of dropping. Further, even when the subject 14 comes into contact with the irradiation surface 44 and an excessive pressure is applied to the electronic cassette 20 from the subject 14 via the irradiation surface 44, inadvertent stress acts on the columnar crystal structure 148. Therefore, the columnar crystal structure 148 may be cracked (broken) or cracked.

Furthermore, when the columnar crystal structure 148 and the radiation conversion panel 64 are pressed against each other, if the misalignment of the columnar crystal structure 148 with respect to the radiation conversion panel 64 due to external impact occurs, the radiation conversion panel 64 Since the surface is damaged, there is a possibility that an image defect of the radiation image may occur due to the generation of the scratch.

Therefore, in the present embodiment, as shown in FIG. 5, the scintillator 150 (covered with the moisture-proof protective agent 152) is disposed inside the radiation conversion panel 64 and the support substrate 144 in a plan view and the scintillator 150. Is surrounded by an airbag 118 (contact mechanism). In this case, as shown in FIG. 4A, the airbag 118 is bonded to the outer edge portion of the radiation conversion panel 64 via an adhesive layer 134. In addition, as shown in FIG. 7, an inflator 120 is connected to the airbag 118. The airbag 118 and the inflator 120 have the same structure as a general automobile airbag and inflator. Further, as shown in a plan view of FIG. 5, since the scintillator 150 is disposed inward of the radiation conversion panel 64 and the support substrate 144, as shown in FIG. 4A, the outer edge portion and the support substrate of the radiation conversion panel 64 are arranged. The outer edge portions of 144 protrude from the scintillator 150 in the left-right direction.

Here, as shown in FIG. 4A, at least during irradiation of radiation 16 to which no impact (impact due to dropping or pressure) is applied from outside, the scintillator 150 and the radiation conversion panel 64 are pressed against (contacted with each other) to form a housing. The relative position of the scintillator 150 in the body 40 and the radiation conversion panel 64 is fixed. Further, even when a doctor is transporting the electronic cassette 20 without dropping the electronic cassette 20, the scintillator 150 and the radiation conversion panel 64 may be brought into contact with each other.

On the other hand, for example, when the doctor accidentally drops the electronic cassette 20 while the electronic cassette 20 is being transported by the doctor, the acceleration value detected by the acceleration sensor 56 exceeds a predetermined threshold value, or the irradiation surface 44. When the subject 14 is positioned relative to the irradiation surface 44, the subject 14 exerts momentum on the irradiation surface 44, thereby applying an excessive pressure to the electronic cassette 20, and the pressure value detected by the pressure sensor 58 becomes a predetermined threshold value. In the case of exceeding the above, an inadvertent stress acts on the columnar crystal structure 148 due to an impact caused by dropping or pressure, and the columnar crystal structure 148 is cracked (broken) or cracked. There is a possibility that scratches on the surface of the radiation conversion panel 64 due to the position shift of 148 may occur.

In such a case, the inflator 120 ignites an igniter (not shown) to generate an inert gas such as nitrogen gas or helium gas, and sends the generated inert gas into the airbag 118. When the inert gas is sent from the inflator 120, the airbag 118 is expanded in the direction of the support substrate 144 by the gas pressure. As a result, the support substrate 144 is pressed by the airbag 118, and as a result, the cushioning material 138 is compressed in the thickness direction of the housing 40 (in the direction of the bottom plate 140), and as shown in FIG. In contrast, the scintillator 150 can be separated. Therefore, the columnar crystal structure 148 is prevented from being cracked (broken) or cracked due to inadvertent stress on the scintillator 150 due to the drop of the electronic cassette 20 or excessive pressure, and further, the generation of scratches on the surface of the radiation conversion panel 64 is avoided. It becomes possible to do.

The airbag 118 is formed with a discharge hole for discharging the inert gas, and the airbag 118 can be contracted by discharging the inert gas through the discharge hole.

In addition, the predetermined threshold mentioned above is an acceleration value set smaller than the magnitude of the gravitational acceleration when the doctor accidentally drops the electronic cassette 20 on the floor or the like during the transportation of the electronic cassette 20, or The pressure value is set to be smaller than the pressure value when the columnar crystal structure 148 is cracked (broken) or cracked and the surface of the radiation conversion panel 64 is damaged due to the pressure applied to the electronic cassette 20. Therefore, if the acceleration value exceeds the threshold value or the pressure value exceeds the threshold value, the columnar crystal structure 148 may be cracked or cracked, and the surface of the radiation conversion panel 64 may be damaged. Immediately before that, the inflator 120 and the airbag 118 are operated to separate the scintillator 150 and the radiation conversion panel 64, so that the scintillator 150 is appropriately protected from impact caused by dropping or pressure.

In the present embodiment, the pressure received by the electronic cassette 20 from the outside may be predicted from the product of the acceleration of the electronic cassette 20 and time. Even if the acceleration (gravitational acceleration) does not reach the level of free fall, if it has been falling for a long time, the speed of the electronic cassette 20 should increase, so that the impact pressure of the electronic cassette 20 becomes considerably large. It is expected to be. Specifically, when the electronic cassette 20 is swung in an arc shape around the position of the handle 54 while the doctor holds the handle 54 (for example, the electronic cassette 20 is slid from the imaging table 12 while the electronic cassette 20 is moved to the imaging table 12). When the electronic cassette 20 is partially struck against the photographing stand 12 and a large impact is applied to the electronic cassette 20, the scintillator 150 can be appropriately protected from the impact.

In the present embodiment, whether or not there is an impact on the electronic cassette 20 is determined based on a shooting technique (for example, shooting in a lying position, shooting in a standing position) on the subject 14 and acceleration of the electronic cassette 20. You may judge. For example, when the electronic cassette 20 is placed on the photographing stand 12 and photographing is performed on the subject 14 in the lying position, when the electronic cassette 20 is moved from the photographing stand 12 after photographing, the photographing stand 12 is moved to the floor surface. There is a risk of dropping the electronic cassette 20. In such a case, the scintillator 150 and the radiation conversion panel 64 may be separated from each other when the acceleration sensor 56 detects an acceleration having a magnitude corresponding to free fall after the end of imaging.

Further, when shooting in a standing position, since shooting is performed with the electronic cassette 20 loaded on a shooting stand (not shown) installed at a relatively high position, the electronic cassette 20 is removed from the shooting stand after shooting. The scintillator 150 and the radiation conversion panel 64 may be separated from each other when the acceleration sensor 56 detects an acceleration having a magnitude corresponding to the free fall when removed.

Further, when the photographing technique is a technique that may cause the electronic cassette 20 to drop before and after photographing, the inflator 120 and the airbag 118 are operated to separate the scintillator 150 and the radiation conversion panel 64 in advance. The scintillator 150 and the radiation conversion panel 64 may be pressed against each other when the electronic cassette 20 is installed on the imaging table 12 (or an imaging table for standing imaging (not shown)).

Furthermore, the present embodiment is not limited to the case where the scintillator 150 and the radiation conversion panel 64 are completely separated as described above, and the scintillator 150 and the radiation conversion panel when the airbag 118 is operated. The contact pressure with 64 may be lower than the contact pressure in a state where the scintillator 150 and the radiation conversion panel 64 are pressed against each other or hardly applied. That is, in the present embodiment, at least the contact control between the scintillator 150 and the radiation conversion panel 64 (pressing of the scintillator 150 and the radiation conversion panel 64) is stopped when the inflator 120 and the airbag 118 are in operation. That's fine.

6A and 6B are cross-sectional views illustrating the configuration of the PSS radiation detector 66 shown in FIG. 3B in more detail. In the PSS type radiation detector 66 as well, as with the ISS type radiation detector 66 in FIGS. 5A and 5B, the airbag 118 is inflated toward the support substrate 144, so that the scintillator 150 and the radiation conversion panel 64 are separated. It is possible to separate (contact control is stopped).

4A to 6B show the case where the airbag 118 is bonded to the outer edge portion of the radiation conversion panel 64 via the adhesive layer 134, but instead, the outer edge of the support substrate 144 is shown. Of course, the airbag 118 may be adhered to the portion via the adhesive layer 134. In this case, when the airbag 118 expands toward the radiation conversion panel 64 and presses the radiation conversion panel 64, the cushioning material 138 is compressed in the direction of the top plate 132 by the reaction force from the radiation conversion panel 64 to the airbag 118. Therefore, as a result, the scintillator 150 and the radiation conversion panel 64 can be separated (contact control is stopped).

FIG. 7 is a schematic electrical configuration diagram of the electronic cassette 20 shown in FIG.

The electronic cassette 20 has a structure in which the pixels 160 are arranged on the matrix TFTs 72. The pixels 160 are arranged in a matrix and have photoelectric conversion elements (not shown). In each pixel 160 to which a bias voltage is supplied from a bias power source 162 that constitutes the drive circuit unit 68, charges generated by photoelectric conversion of visible light (fluorescence) are accumulated, and the TFTs 72 are sequentially turned on for each column. Thus, a charge signal (electric signal) can be read out as a pixel value of an analog signal via each signal line 166. In FIG. 7, for the sake of convenience, the pixels 160 and the TFTs 72 are arranged in a 4 × 4 arrangement, but it is needless to say that a desired number of arrangements may be used.

The TFT 72 connected to each pixel 160 is connected to a gate line 164 extending in the row direction and a signal line 166 extending in the column direction. Each gate line 164 is connected to a gate drive unit 168 constituting the drive circuit unit 68, and each signal line 166 is connected via a charge amplifier 170 to a multiplexer unit 172 constituting the drive circuit unit 68. The multiplexer unit 172 is connected to an AD conversion unit 174 that converts an electrical signal of an analog signal into an electrical signal of a digital signal. The AD conversion unit 174 outputs an electrical signal (a pixel value of the digital signal, hereinafter also referred to as a digital value) converted into a digital signal to the cassette control unit 110.

The cassette control unit 110 controls the entire electronic cassette 20. In this case, the computer can function as the cassette control unit 110 by causing the information processing apparatus such as a computer to read a predetermined program.

The cassette control unit 110 is connected with a memory 112 and a communication unit 114. The memory 112 stores pixel values of digital signals, and the communication unit 114 transmits and receives signals to and from the console 22. The communication unit 114 packet-transmits one image (one frame image) configured by arranging a plurality of pixel values in a matrix. The power supply unit 116 supplies power to the cassette control unit 110, the memory 112, the communication unit 114, and the like. The bias power supply 162 supplies the power transmitted from the cassette control unit 110 to each pixel 160.

The cassette control unit 110 includes a read control unit 180, an impact prediction determination unit 182, a separation instruction unit 184, and a contact instruction unit 186.

The read control unit 180 controls the gate driving unit 168, the charge amplifier 170, the multiplexer unit 172, and the AD conversion unit 174 to sequentially read out the electrical signals accumulated in the pixels 160 in units of one row.

The impact prediction determination unit 182 determines whether the acceleration value detected by the acceleration sensor 56 or the pressure value detected by the pressure sensor 58 exceeds a predetermined threshold value. That is, the impact prediction determination unit 182 is based on the detection result of the acceleration sensor 56 or the pressure sensor 58, such as collision (falling) of the electronic cassette 20 on the floor surface or application of excessive pressure to the electronic cassette 20. It is determined (predicted) whether or not the impact applied to the electronic cassette 20 from the outside is such that the columnar crystal structure 148 is cracked (broken) or cracked and the surface of the radiation conversion panel 64 is damaged.

Then, when the value of the acceleration detected by the acceleration sensor 56 exceeds the threshold value or when the pressure value detected by the pressure sensor 58 exceeds the threshold value, the impact prediction determination unit 182 A notification signal is output to the separation instructing unit 184 for notifying that an impact that may cause cracks (breaks) or cracks in the columnar crystal structure 148 and scratches on the surface of the radiation conversion panel 64 is applied.

The acceleration sensor 56 sequentially detects acceleration and sequentially outputs a detection signal indicating the detected acceleration to the cassette control unit 110, while the pressure sensor 58 sequentially detects pressure and a detection signal indicating the detected pressure. Are sequentially output to the cassette control unit 110. Therefore, after the impact prediction determination unit 182 outputs the notification signal to the separation instruction unit 184, this time, whether or not the acceleration value detected by the acceleration sensor 56 falls below the threshold value or the detection by the pressure sensor 58. It is determined whether or not the measured pressure value falls below a threshold value. The impact prediction determination unit 182 notifies that there is no possibility that an impact is applied to the electronic cassette 20 from the outside when the acceleration value is lower than the threshold value and the pressure value is lower than the threshold value. A signal is output to the contact instruction unit 186.

By the way, the total weight of the electronic cassette 20 is m, the distance (falling distance) between the electronic cassette 20 and the floor surface at the start of dropping is h, the weight acceleration is g, and the electronic cassette 20 falls (collises) on the floor surface. Assuming that the instantaneous drop speed is v and the drop time required from the start of the drop to the collision with the floor surface is t, the drop speed v and the drop time t are v = (2 × g × h) ^1/2 , respectively. t = (2 × h / g) ^1/2 .

Therefore, instead of determining the prediction of impact using the acceleration value, the impact prediction determination unit 182 uses a predetermined time set shorter than the falling time t as a threshold value, and the acceleration value detected by the acceleration sensor 56 is substantially zero. When a predetermined level value that can be regarded as a fall of the electronic cassette 20 from the level is reached, the drop start time is set, and when the predetermined time has elapsed from the drop start time and the threshold value is reached, the separation instruction unit 184 is notified. A signal may be output. In this case, since the impact prediction determination unit 182 counts the elapsed time from the drop start time set based on the acceleration value detected by the acceleration sensor 56, the collision is predicted, so the elapsed time measured is also the electronic cassette. This is a physical quantity related to 20 movements.

The separation instruction unit 184 receives an operation start instruction signal for operating the airbag 118 (stops contact control between the radiation conversion panel 64 and the scintillator 150) when the notification signal is input from the impact prediction determination unit 182. 120 is output. When the operation start instruction signal is input, the inflator 120 ignites the igniter, generates an inert gas, and sends it to the airbag 118. On the other hand, when the notification signal is input from the impact prediction determination unit 182, the contact instruction unit 186 stops the operation of the inflator 120 (starts contact control between the radiation conversion panel 64 and the scintillator 150). The signal is output to the inflator 120. When the operation stop instruction signal is input, the inflator 120 stops sending the inert gas to the airbag 118.

[Operation of this embodiment]
The radiation imaging system 10 having the electronic cassette 20 according to the present embodiment is basically configured as described above. Next, the operation thereof will be described with reference to the flowcharts of FIGS. 8 and 9. .

Here, first, referring to FIG. 8, the basic operation of the radiation imaging system 10, that is, the cause of the cracks (cracks) and cracks of the columnar crystal structure 148, and further the generation of scratches on the surface of the radiation conversion panel 64 is described. The operation (normal operation) of the radiation imaging system 10 when no impact is applied to the electronic cassette 20 will be described.

Next, referring to FIG. 9, when the electronic cassette 20 is accidentally dropped while the electronic cassette 20 is being transported by a doctor, or when the subject 14 is positioned, the subject 14 vigorously contacts the irradiation surface 44. An operation (operation of the inflator 120 and the airbag 118) inside the electronic cassette 20 when an excessive pressure is applied to the electronic cassette 20 will be described.

8, the doctor sets imaging conditions for the subject 14 based on the order information acquired by the console 22 from the RIS 26 or the HIS 28. Note that the order information is created by a doctor in the RIS 26 or HIS 28, and in addition to subject information for specifying the subject 14 such as the name, age, and sex of the subject 14, radiation output used for imaging. The information of the apparatus 18 and the electronic cassette 20, the imaging part of the subject 14, the procedure in imaging, and the like are included. The imaging conditions are various conditions necessary for irradiating the imaging region of the subject 14 with the radiation 16 such as the tube voltage and tube current of the radiation source 30 and the exposure time of the radiation 16.

In the next step S2, the doctor grasps the handle 54 of the electronic cassette 20 stored in a predetermined storage location, conveys the electronic cassette 20, and installs it on the imaging table 12. In the next step S 3, the doctor lays the subject 14 on the imaging table 12 and the electronic cassette 20 so that the imaging region of the subject 14 falls within the imaging region 52, and positions the imaging region with respect to the imaging region 52. I do.

In this case, the power supply unit 116 constantly supplies power to the cassette control unit 110, the communication unit 114, the acceleration sensor 56, and the pressure sensor 58. Therefore, the acceleration sensor 56 sequentially detects the acceleration of the electronic cassette 20 and sequentially outputs a detection signal indicating the detected acceleration to the cassette control unit 110. The pressure sensor 58 sequentially detects the pressure applied to the electronic cassette 20 from the outside, and sequentially outputs a detection signal indicating the detected pressure to the cassette control unit 110.

Here, pressure is applied from the subject 14 to the electronic cassette 20 by positioning the imaging region of the subject 14 in the imageable region 52. Therefore, the pressure sensor 58 detects the pressure applied from the subject 14 and outputs a detection signal indicating the pressure to the cassette control unit 110. The impact prediction determination unit 182 determines that the subject 14 is currently positioned when the level of the pressure value indicated by the detection signal is a level of pressure that is applied to the electronic cassette 20 from the subject 14.

The cassette control unit 110 starts power supply from the power supply unit 116 to the drive circuit unit 68, the display operation unit 122, and the speaker 124 based on the determination result of the impact prediction determination unit 182. As a result, the bias power supply 162 starts to supply a bias voltage to each pixel 160, so that each pixel 160 is in a state where charge can be accumulated. In addition, the display operation unit 122 displays various types of information and reaches a state where an input operation by a doctor is possible. Furthermore, the speaker 124 reaches a state where a signal from the cassette control unit 110 can be output to the outside as a sound. As a result, the electronic cassette 20 is switched from the sleep state to the activated state.

Also, the cassette control unit 110 transmits a transmission request signal for requesting transmission of order information and imaging conditions to the console 22 wirelessly via the communication unit 114 based on the determination result of the impact prediction determination unit 182. When the console 22 receives the transmission request signal, it transmits the order information and the imaging conditions to the electronic cassette 20 by radio and transmits the imaging conditions to the radiation output device 18 by radio. Thereby, in the radiation output device 18, the received imaging condition is registered in the radiation control device 32. In the electronic cassette 20, the received order information and the imaging conditions are registered in the cassette control unit 110. The cassette control unit 110 may display the information on the display operation unit 122 when receiving the order information and the imaging conditions.

In step S4, when the doctor half-presses the radiation switch 34, the radiation control device 32 prepares for irradiation of the radiation 16, and transmits a notification signal notifying the preparation for irradiation to the console 22 wirelessly. The console 22 transmits a synchronization control signal for synchronizing with irradiation of the radiation 16 from the radiation source 30 to the electronic cassette 20 by radio. When the cassette control unit 110 of the electronic cassette 20 receives the synchronization control signal, the cassette control unit 110 displays information indicating that the irradiation preparation has been started on the display operation unit 122 and also notifies the outside via the speaker 124 as a sound. Good.

Thereafter, when the doctor fully presses the radiation switch 34, the radiation control device 32 irradiates the imaging region of the subject 14 with the radiation 16 from the radiation source 30 for a predetermined time set under the imaging conditions (step S5). In this case, the radiation control device 32 may transmit a notification signal for notifying the start of irradiation to the console 22 wirelessly simultaneously with the start of irradiation of the radiation 16. The console 22 transfers the received notification signal to the electronic cassette 20, and when the cassette control unit 110 of the electronic cassette 20 receives the notification signal, the display operation unit 122 displays information indicating that irradiation is being performed. At the same time, the sound may be notified to the outside through the speaker 124.

In step S6 in which the radiation 16 passes through the imaging region of the subject 14 and reaches the radiation detector 66 of the electronic cassette 20, if the radiation detector 66 is the ISS radiation detector shown in FIG. 16 reaches the columnar crystal structure 148 of the scintillator 150 through the radiation conversion panel 64 and the moisture-proof protective material 152.

The columnar crystal structure 148 emits visible light (fluorescence) having an intensity corresponding to the intensity of the radiation 16, and the fluorescence proceeds from the columnar portion to the tip portion of the columnar crystal structure 148 via the moisture-proof protective material 152. Then, it enters the radiation conversion panel 64. Note that some fluorescence may travel toward the non-columnar crystal portion 146, but is reflected to the columnar crystal structure 148 side at the non-columnar crystal portion 146 or the support substrate 144, and thus the partial fluorescence also It becomes possible to enter the radiation conversion panel 64.

Each pixel 160 constituting the radiation conversion panel 64 converts fluorescence into an electric signal and accumulates it as electric charge. Next, the charge information that is a radiographic image of the imaging region of the subject 14 held in each pixel 160 is read according to the drive signal supplied from the read control unit 180 constituting the cassette control unit 110 to the gate drive unit 168.

That is, the gate driver 168 sequentially selects the gate line 164 from the 0th row, supplies a gate signal to the selected gate line 164, and turns on the TFT 72 to which the gate signal is supplied. The charges accumulated in 160 are sequentially read from the 0th row in units of rows. The electric charges sequentially read out from each pixel 160 in units of rows are input to the charge amplifiers 170 in the respective columns through the signal lines 166, and then the electric signals of the digital signals are input through the multiplexer unit 172 and the AD conversion unit 174. The signal is stored in the memory 112 (step S7). That is, the memory 112 sequentially stores image data for one row obtained in units of rows.

The radiographic image stored in the memory 112 is transmitted to the console 22 wirelessly through the communication unit 114 together with the cassette ID information for identifying the electronic cassette 20. The console 22 displays the received radiation image and cassette ID information on the display device 24 (step S8). Further, the cassette control unit 110 may cause the display operation unit 122 to display both the radiation image and the cassette ID information.

The doctor visually confirms the display contents of the display device 24 or the display operation unit 122 and confirms that the radiation image is obtained, and then releases the subject 14 from the positioning state (step S9). Even in this case, the pressure sensor 58 sequentially detects the pressure applied to the electronic cassette 20 from the outside, and sequentially outputs the detection signal to the cassette control unit 110. The impact prediction determination unit 182 It is determined that the subject 14 has been released from the positioning state when the pressure level shown in FIG.

Then, the cassette control unit 110 stops the power supply from the power supply unit 116 to the drive circuit unit 68, the display operation unit 122, and the speaker 124 based on the determination result of the impact prediction determination unit 182. Thereby, the supply of the bias voltage from the bias power source 162 to each pixel 160 is stopped, and the operations of the display operation unit 122 and the speaker 124 are also stopped. As a result, the electronic cassette 20 shifts from the activated state to the sleep state.

In step S <b> 10, after confirming that the display on the display operation unit 122 has disappeared and the electronic cassette 20 has shifted to the sleep state, the doctor grasps the handle 54 of the electronic cassette 20 and stores the electronic cassette 20 in a predetermined storage state. Transport to location.

Next, the operation of FIG. 9 will be described.

During steps S2, S3, S9, and S10, the acceleration sensor 56 sequentially detects the acceleration of the electronic cassette 20, and sequentially outputs detection signals indicating the detected acceleration to the cassette control unit 110, while the pressure sensor 58 is externally connected. The pressure applied to the electronic cassette 20 is sequentially detected, and a detection signal indicating the detected pressure is sequentially output to the cassette control unit 110 (step S21).

In this case, the impact prediction determination unit 182 of the cassette control unit 110 causes the acceleration value indicated by the detection signal from the acceleration sensor 56 to exceed a predetermined threshold every time detection signals are input from the acceleration sensor 56 and the pressure sensor 58. It is determined whether or not the pressure value indicated by the detection signal from the pressure sensor 58 exceeds a predetermined threshold (allowable value) (step S22).

In step S22, when the acceleration value does not reach the predetermined threshold value and the pressure value does not reach the predetermined threshold value (step S22: NO), the impact prediction determination unit 182 determines that the columnar crystal It is determined that a large impact that causes cracks (breaks) or cracks in the structure 148 and further damage to the surface of the radiation conversion panel 64 has not been applied to the electronic cassette 20, and waiting for input of the next detection signal; Become.

On the other hand, when the acceleration value exceeds the predetermined threshold value or the pressure value exceeds the predetermined threshold value in step S22 (step S22: YES), the impact prediction determination unit 182 causes an external impact. It is determined that there is a possibility that cracks (breaks) or cracks in the columnar crystal structure 148 and scratches on the surface of the radiation conversion panel 64 may occur (step S23), and notification is given that an impact is applied to the electronic cassette 20 from the outside. The notification signal is output to the separation instruction unit 184.

In step S24, the separation instruction unit 184 outputs an operation start instruction signal to the inflator 120 based on the notification signal from the impact prediction determination unit 182, and the inflator 120 generates the ignition agent based on the input operation start instruction signal. Is ignited and an inert gas is generated and sent into the airbag 118. Thereby, the airbag 118 is expanded in the direction of the support substrate 144 by the fed inert gas, and presses the support substrate 144. As a result, the cushioning material 138 is compressed in the direction of the bottom plate 140, so that the scintillator 150 can be separated from the radiation conversion panel 64 as shown in FIG. 4B.

In addition, when the notification signal is input from the impact prediction determination unit 182, the separation instruction unit 184 operates the airbag 118 due to an external impact, and the radiation conversion panel 64 and the scintillator 150 are separated. A warning signal indicating this is output to the display operation unit 122 and the speaker 124. The display operation unit 122 displays information indicated by the warning signal, and the speaker 124 outputs the warning signal to the outside as a sound (step S25). As a result, the doctor visually recognizes the display content of the display operation unit 122 and / or listens to the sound from the speaker 124, whereby the airbag 118 is activated by an external impact, and the radiation conversion panel 64 is displayed. On the other hand, it can be grasped that the scintillator 150 is separated.

Thus, since the airbag 118 operates and the radiation conversion panel 64 and the scintillator 150 are separated from each other, the electronic cassette 20 actually falls on the floor surface, or the subject 14 vigorously moves with respect to the irradiation surface 44. Even if an impact is applied to the electronic cassette 20 from the outside (step S26), the columnar crystal structure 148 may be cracked (broken) or cracked in the columnar crystal structure 148 and scratched on the surface of the radiation conversion panel 64. Structure 148 can be adequately protected.

Thereafter, if a predetermined time has elapsed since the operation of the airbag 118 (step S27: YES), the impact prediction determination unit 182 determines that there is no possibility of an impact being applied to the electronic cassette 20 from the outside, and the contact A notification signal is output to the instruction unit 186. In step S28, the contact instruction unit 186 outputs an operation stop instruction signal to the inflator 120 based on the notification signal, and the inflator 120 generates an inert gas to the airbag 118 based on the input operation stop instruction signal. Stops sending. As a result, the inert gas in the airbag 118 is discharged from a discharge hole (not shown), and the airbag 118 contracts. As a result, the radiation conversion panel 64 and the scintillator 150 come into contact again and return to the original state (the original state is restored).

Further, the contact instruction unit 186 deletes the warning display of the display operation unit 122 based on the notification signal and stops the warning sound from the speaker 124 (step S29). Thereby, the doctor can easily grasp that the radiation conversion panel 64 and the scintillator 150 are brought into contact with each other again and the original state is recovered.

Even during the operation of the airbag 118, the acceleration sensor 56 sequentially detects the acceleration of the electronic cassette 20, and sequentially outputs detection signals indicating the detected acceleration to the cassette control unit 110, while the pressure sensor 58 is externally applied. Since it is possible to sequentially detect the pressure applied to the electronic cassette 20 and sequentially output a detection signal indicating the detected pressure to the cassette control unit 110, the impact prediction determination unit 182 When the acceleration value falls below a predetermined threshold value and the pressure value falls below a predetermined threshold value, it is determined that there is no possibility that an impact is applied to the electronic cassette 20 from the outside, and the contact instruction unit 186 is notified. A notification signal may be output. Even in this case, the radiation conversion panel 64 and the scintillator 150 can be reliably returned to the original state.

Further, since the inert gas in the airbag 118 is discharged from a discharge hole (not shown), if the inflator 120 is configured to send the inert gas to the airbag 1118 only when the ignition agent is ignited, the process of step S27 is performed. It may be omitted. In this case, since the airbag 118 contracts by discharging the inert gas from the discharge hole, the radiation conversion panel 64 and the scintillator 150 can be returned to the original state after the contraction.

Further, in the above description, the case where a warning is given via the display on the display operation unit 122 or the sound from the speaker 124 has been described. May be sent. As a result, the console 22 causes the display device 24 to display a warning display content corresponding to the received warning signal, and the doctor visually recognizes the display content of the display device 24, whereby the airbag 118 is activated by an external impact. Then, it can be grasped that the radiation conversion panel 64 and the scintillator 150 are separated. Further, the contact instruction unit 186 transmits a signal for causing the console 22 to delete the warning display wirelessly via the communication unit 114, and the console 22 displays a warning display on the display device 24 based on the received signal. Erase. Thereby, the doctor can grasp | ascertain that the radiation conversion panel 64 and the scintillator 150 contacted again, and the original state was recovered.

[Effect of this embodiment]
As described above, according to the electronic cassette 20 according to the present embodiment, at least when the radiation detector 66 is irradiated with the radiation 16, the scintillator 150 and the radiation conversion panel 64 are in contact with each other, while the acceleration sensor 56 detects the radiation. The scintillator 150 and the radiation conversion panel 64 are separated when the acceleration value detected, the pressure value detected by the pressure sensor 58, or the drop time of the electronic cassette 20 based on the acceleration exceeds a predetermined threshold (scintillator 150 and the radiation conversion panel 64 are stopped), so that even when an impact is applied to the electronic cassette 20 from the outside, the scintillator 150 (the columnar crystal structure 148) is appropriately protected from the impact. Generation of cracks (cracks) and cracks of the columnar crystal structure 148 due to the impact, Raniwa, it is possible to reliably avoid the occurrence of scratches on the radiation conversion panel 64 surface due to positional deviation of the columnar crystal structure 148 due to the impact.

In this case, the tip portion of the columnar crystal structure 148 comes into contact with the radiation conversion panel 64 via the moisture-proof protective material 152, so that the fluorescence converted from the radiation 16 by the columnar crystal structure 148 is efficiently incident on the radiation conversion panel 64. be able to. When there is a possibility of receiving an impact from the outside, the tip of the columnar crystal structure 148 and the moisture-proof protective material 152 are separated from the radiation conversion panel 64 by the operation of the airbag 118. As described above, even if the electronic cassette 20 may receive an impact from the outside, the columnar crystal structure 148 can be reliably protected from the impact, so that the imaging performance of the electronic cassette 20 can be improved regardless of the impact. Can be maintained.

Further, the inert gas is sent from the inflator 120 to the airbag 118, and the airbag 118 is inflated along the thickness direction of the housing 40, whereby the radiation conversion panel 64 and the scintillator 150 are separated from each other. The radiation conversion panel 64 and the scintillator 150 can be quickly separated from the impact. Further, the supply of the inert gas from the inflator 120 is stopped, and / or the inert gas is discharged from the discharge hole of the airbag 118, so that the airbag 118 is contracted, and the radiation conversion panel 64 Since the scintillator 150 can be brought into contact with the scintillator 150 again, it is easy to return the radiation conversion panel 64 and the scintillator 150 once separated to the original state (recover the original state).

Further, in the plan view of FIG. 5, the airbag 118 is disposed on the outer edge portion of the support substrate 144 and the outer edge portion of the radiation conversion panel 64 so as to surround the scintillator 150. By inflating the airbag 118 in the thickness direction of the housing 40 between the outer edge of the conversion panel 64, the tip portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be connected regardless of the plane size of the scintillator 150. It can be separated accurately and reliably.

As described above, when the doctor half-presses the radiation switch 34, the radiation control device 32 wirelessly transmits a notification signal for notifying preparation for irradiation of the radiation 16 to the console 22, and the console 22 performs synchronous control. The signal is transmitted to the electronic cassette 20 by radio.

Therefore, in the present embodiment, the scintillator 150 and the radiation conversion panel are used in a time zone before preparation for irradiation of the radiation 16 that may cause an impact to the electronic cassette 20 from the outside and a time zone after irradiation with the radiation 16. The inflator 120 and the airbag 118 are operated so as to be separated from each other, while the inflator 120 and the airbag are in a time zone from when the electronic cassette 20 receives the synchronization control signal to after irradiation of the radiation 16. The operation of 118 may be stopped and the scintillator 150 and the radiation conversion panel 64 may be brought into contact with each other. For example, when positioning the subject 14, an excessive load (pressure) is applied from the subject 14 to the electronic cassette 20, which may cause cracks and cracks in the columnar crystal structure 148 and scratches on the surface of the radiation conversion panel 64. The scintillator 150 and the radiation conversion panel 64 are separated from each other during a time zone in which such an impact is likely to be applied.

That is, in this embodiment, since the scintillator 150 and the radiation conversion panel 64 are in contact with each other only during irradiation of the radiation 16 that is less likely to receive an impact from the outside, the scintillator 150 is appropriately protected from the impact. In addition, an appropriate radiographic image can be acquired without deteriorating the imaging performance of the electronic cassette 20. That is, in the electronic cassette 20, the scintillator 150 and the radiation conversion panel 64 are brought into contact with each other before the irradiation of the radiation 16 on the subject 14 based on the registration of the order information. The conversion panel 64 can be separated.

[Modification of this embodiment]
Next, modified examples (first to eighth modified examples) of the present embodiment will be described with reference to FIGS. 10A to 17B.

In these modifications, the same components as those in FIGS. 1 to 9 are described with the same reference numerals, and detailed description thereof is omitted.

In the first modified example, as shown in FIGS. 10A and 10B, an accommodation bag 190 (contact mechanism) that accommodates the radiation detector 66 is disposed between the top plate 132 and the bottom plate 140 in the housing 40. ing.

In this case, the bottom plate 140 side of the storage bag 190 is bonded to the bottom plate 140 via the adhesive layer 198, while the top plate 132 side of the storage bag 190 is bonded to the top plate 132 via the adhesive layer 200. Yes. The radiation detector 66 is accommodated in the chamber 192 of the accommodation bag 190. Here, as an example, in the case of the ISS type radiation detector 66, the support substrate 144 is bonded to the bottom plate 140 side of the containing bag 190 via the adhesive layer 204, while the radiation conversion panel 64 is bonded to the adhesive layer 202. Is attached to the top plate 132 side of the storage bag 190.

In addition, the storage bag 190 is provided with a passage 194 communicating with the chamber 192, and a leak valve 196 is provided in the middle of the passage 194.

In the case of FIG. 10A, the leak valve 196 is in a valve-closed state, prevents air from entering the chamber 192 via the passage 194, and places the chamber 192 in a negative pressure state. As a result, the tip portion of the columnar crystal structure 148 and the radiation conversion panel 64 are brought into contact with each other via the moisture-proof protective material 152, and a radiographic image can be captured.

On the other hand, when the acceleration value detected by the acceleration sensor 56 exceeds a predetermined threshold value, or when the pressure value detected by the pressure sensor 58 exceeds a predetermined threshold value, the impact prediction determination unit 182 generates an electronic Based on the notification signal from the impact prediction determination unit 182, the separation instruction unit 184 switches the leak valve 196 from the valve closed state to the valve open state. As a result, air enters the chamber 192 through the passage 194 and the chamber 192 is in an atmospheric pressure state. As a result, as shown in FIG. 10B, the housing bag 190 expands along the thickness direction of the housing 40 (vertical direction in FIG. 10B), and separates the distal end portion of the columnar crystal structure 148 from the radiation conversion panel 64. be able to. In FIG. 10B, when the storage bag 190 is inflated along the thickness direction of the housing 40, the storage bag 190 presses the top plate 132 and the bottom plate 140 of the housing 40. Therefore, as compared with the case of FIG. Thus, the thickness of the housing 40 in the vicinity of the containing bag 190 is increased.

When there is no possibility of impact to the electronic cassette 20 from the outside, the contact instruction unit 186 operates a vacuum pump (not shown) to discharge the air in the chamber 192 through the passage 194 and bring it into a negative pressure state. After that, the leak valve 196 is switched from the valve open state to the valve closed state, and the radiation conversion panel 64 and the scintillator 150 are brought into contact again as shown in FIG. 10A.

As described above, in the first modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by switching the leak valve 196 to the valve open state or the valve closed state (contact with the radiation conversion panel 64 and the scintillator 150). Therefore, even if an impact is applied to the electronic cassette 20 from the outside, the scintillator 150 can be appropriately protected. Also in the first modified example, it is needless to say that the effects of the present embodiment can be easily obtained by bringing the radiation conversion panel 64 and the scintillator 150 into contact with or separating from each other.

In the first modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other while the radiation detector 66 is housed in the housing bag 190. Thus, the radiation conversion panel 64 and the scintillator 150 may be contacted or separated from each other.

In the second modified example, as shown in FIGS. 11A and 11B, a plunger 212 (lock member) is fixed to a position in the vicinity of the radiation detector 66 in the bottom plate 140 in the housing 40, and the plunger 212 and the top plate 132 are fixed. A spring member 214 (contact mechanism) is interposed between the two. The support substrate 144 is bonded to the bottom plate 140 via the adhesive layer 210, and the radiation conversion panel 64 is bonded to the top plate 132 via the adhesive layer 130.

In the case of FIG. 11A, when the plunger 212 pulls the spring member 214 toward the bottom plate 140 against the elastic force of the spring member 214, the spring member 214 is compressed (locked) in the thickness direction of the housing 40. As a result, the tip of the columnar crystal structure 148 and the radiation conversion panel 64 are brought into contact with each other, and a radiographic image can be captured.

On the other hand, the impact prediction determination unit 182 determines that an impact may be applied to the electronic cassette 20 from the outside, and the separation instruction unit 184 receives the spring member 214 from the plunger 212 based on the notification signal from the impact prediction determination unit 182. When a lock release signal instructing release (lock release) is output, the plunger 212 stops pulling on the spring member 214, and the spring member 214 expands toward the top plate 132 side by elastic force. Thereby, as shown in FIG. 11B, the tip portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be separated. In FIG. 11B, when the spring member 214 extends to the top plate 132 side, the spring member 214 presses the top plate 132, so that the thickness of the housing 40 in the vicinity of the radiation detector 66 is compared with the case of FIG. 11A. Becomes thicker.

When there is no possibility that an impact is applied to the electronic cassette 20 from the outside, the contact instruction unit 186 operates the plunger 212 again to contract the spring member 214 to the bottom plate 140 side, and as shown in FIG. The conversion panel 64 and the scintillator 150 are brought into contact again.

As described above, also in the second modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by the operation of the plunger 212 and the spring member 214 (contact control for the radiation conversion panel 64 and the scintillator 150 is executed or stopped). Therefore, the same effect as the second modification can be obtained.

In the third modification, as shown in FIGS. 12A and 12B, a piezoelectric actuator 226 in which a piezoelectric element 220 (contact mechanism) is sandwiched between two

electrodes

222 and 224 at a location near the radiation detector 66 in the housing 40. Is interposed between the top plate 132 and the bottom plate 140.

As shown in FIG. 12A, when the switch 230 provided between the power supply 228 such as the power supply unit 116 and the electrode 222 is off, the piezoelectric actuator 226 does not operate, and the distal end portion of the columnar crystal structure 148 and the radiation conversion panel 64. And the radiographic image can be captured.

On the other hand, when the impact prediction determination unit 182 determines that a shock may be applied to the electronic cassette 20 from the outside, and the separation instruction unit 184 turns on the switch 230 based on the notification signal from the impact prediction determination unit 182. A voltage is applied from the power source 228 to each of the

electrodes

222 and 224, and the piezoelectric element 220 is compressed in the width direction of the housing 40 and expanded in the thickness direction of the housing 40. Thereby, as shown in FIG. 12B, the distal end portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be separated. In FIG. 12B, when the piezoelectric element 220 expands in the thickness direction of the housing 40, the top plate 132 and the bottom plate 140 are pressed, so that the housing 40 in the vicinity of the radiation detector 60 is compared with the case of FIG. 12A. The thickness of becomes thicker.

When there is no possibility that an impact is applied to the electronic cassette 20 from the outside, the contact instruction unit 186 turns off the switch 230 again to bring the radiation conversion panel 64 and the scintillator 150 into contact again as shown in FIG. 12A. .

Thus, also in the third modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by the operation of the piezoelectric actuator 226 (contact control with respect to the radiation conversion panel 64 and the scintillator 150 is executed or stopped). The same effects as those of the second modification can be obtained.

In the fourth modified example, as shown in FIG. 13A, the plunger 212 and the spring member 214 are inserted between the radiation conversion panel 64 and the support substrate 144, or as shown in FIG. 13B, the piezoelectric actuator 226 is inserted. Is interposed between the radiation conversion panel 64 and the support substrate 144.

Even in this case, due to the operation of the plunger 212 and the spring member 214, or the operation of the piezoelectric actuator 226, the radiation conversion panel 64 and the support substrate 144 are pressed, and the radiation conversion panel 64 and the scintillator 150 come into contact with each other. Alternatively, since they are separated from each other, the same effects as those of the second and third modifications can be obtained.

In the fifth modification, as shown in FIGS. 14A and 14B, an airbag 240 (contact mechanism) is interposed between the support substrate 144 and the bottom plate 140. In this case, the airbag 240 is bonded to the bottom plate 140 via the adhesive layer 136, and the support substrate 144 is bonded to the airbag 240 via the adhesive layer 142.

As shown in FIG. 14A, when the airbag 240 is inflated in the thickness direction of the casing 40 by the inert gas sent from the inflator 120, the distal end portion of the columnar crystal structure 148 and the radiation conversion panel 64 come into contact with each other, and a radiographic image is captured. Is possible.

On the other hand, the impact prediction determination unit 182 determines that an impact may be applied to the electronic cassette 20 from the outside, and the separation instruction unit 184 generates an inert gas from the inflator 120 based on the notification signal from the impact prediction determination unit 182. Is stopped, the inert gas in the airbag 240 is discharged through a discharge hole (not shown). As a result, the airbag 240 contracts in the thickness direction of the casing 40 (the direction of the bottom plate 140). As a result, the tip portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be separated as shown in FIG. 14B.

When there is no possibility that an impact is applied to the electronic cassette 20 from the outside, when the contact instructing unit 186 operates the inflator 120 again to resume the supply of the inert gas to the airbag 240, as shown in FIG. 14A. In addition, the radiation conversion panel 64 and the scintillator 150 come into contact again.

Thus, also in the fifth modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by the operation of the airbag 240 and the inflator 120 (contact control for the radiation conversion panel 64 and the scintillator 150 is executed or stopped). Therefore, the same effects as in the present embodiment and the first to fourth modifications can be obtained.

As shown in FIGS. 15A and 15B, in the sixth modification, a cam 254 (contact mechanism) that is an eccentric cam is provided on the rotary shaft 252 provided at the upper ends of the two support members 250 erected on the bottom plate 140. The support substrate 144 is supported by two cams 254 that are respectively pivotally supported.

If the rotation angle of the cam 254 with respect to the rotation shaft 252 is the angle shown in FIG. 15A, the distal end portion of the columnar crystal structure 148 comes into contact with the radiation conversion panel 64, and a radiographic image can be captured.

On the other hand, the impact prediction determination unit 182 determines that an impact may be applied to the electronic cassette 20 from the outside, and the separation instruction unit 184 is centered on the rotating shaft 252 based on the notification signal from the impact prediction determination unit 182. When the cam 254 is rotated, the support substrate 144 descends to the bottom plate 140 side, so that the distal end portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be separated as shown in FIG. 15B.

When there is no possibility that an impact is applied to the electronic cassette 20 from the outside, the radiation conversion panel 64 and the scintillator 150 are obtained when the contact instruction unit 186 rotates the cam 254 about the rotation shaft 252 to the rotation angle shown in FIG. Can be contacted again.

Thus, also in the sixth modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by the rotational operation of the cam 254 around the rotation shaft 252 (contact control with respect to the radiation conversion panel 64 and the scintillator 150). Therefore, the same effects as in the present embodiment and the first to fifth modifications can be obtained.

In the seventh modification, as shown in FIGS. 16A and 16B, an airbag 274 (contact mechanism) is interposed between the radiation conversion panel 64 and the top plate 132. In this case, the airbag 274 is bonded to the top plate 132 via the adhesive layer 272, and the radiation conversion panel 64 is bonded to the airbag 274 via the adhesive layer 276. Further, the support substrate 144 is also bonded to the bottom plate 140 through the adhesive layer 270.

As shown in FIG. 16A, when the airbag 274 is inflated in the thickness direction of the housing 40 by the inert gas sent from the inflator 120, the distal end portion of the columnar crystal structure 148 comes into contact with the radiation conversion panel 64, and radiographic images are captured. Is possible.

On the other hand, the impact prediction determination unit 182 determines that an impact may be applied to the electronic cassette 20 from the outside, and the separation instruction unit 184 determines the inert gas generated by the inflator 120 based on the notification signal from the impact prediction determination unit 182. When the supply is stopped, the inert gas in the airbag 274 is discharged through a discharge hole (not shown). As a result, the airbag 274 contracts in the thickness direction of the casing 40 (the direction of the top plate 132). As a result, the tip portion of the columnar crystal structure 148 and the radiation conversion panel 64 can be separated as shown in FIG. 16B.

If there is no possibility that an impact is applied to the electronic cassette 20 from the outside, the contact instructing unit 186 operates the inflator 120 again to restart the supply of the inert gas to the airbag 274. Thus, the radiation conversion panel 64 and the scintillator 150 come into contact again.

Thus, also in the seventh modification, the radiation conversion panel 64 and the scintillator 150 are brought into contact with or separated from each other by the operation of the airbag 274 and the inflator 120 (contact control for the radiation conversion panel 64 and the scintillator 150 is executed or stopped). Therefore, the same effect as that of the fifth modification can be obtained.

Further, the radiation detector 66 may be configured as shown in FIGS. 17A and 17B (eighth modification). In the eighth modification, the specific configuration of the radiation detector 66 using the scintillator made of CsI described in the present embodiment will be described in detail.

17A and 17B, the radiation detector 66 converts the radiation 16 transmitted through the subject 14 into visible light (absorbs the radiation 16 and emits visible light), and the scintillator. The radiation detection unit 502 converts the visible light converted in 500 into an electrical signal (charge) corresponding to the radiation image. The scintillator 500 corresponds to the aforementioned scintillator 150, and the radiation detection unit 502 corresponds to the radiation conversion panel 64. Moreover, in FIG. 17A and FIG. 17B, illustration of the moisture-proof protective material 152 is abbreviate | omitted.

As described above, as the radiation detector 66, as shown in FIGS. 17A and 17B, an ISS system in which the radiation detection unit 502 and the scintillator 500 are arranged in this order with respect to the irradiation surface 44 irradiated with the radiation 16; There is a PSS system in which the scintillator 500 and the radiation detection unit 502 are arranged in this order with respect to the irradiation surface 44.

The scintillator 500 emits light more strongly on the irradiation surface 44 side on which the radiation 16 is incident. In the ISS system, the light emission position in the scintillator 500 is close to the radiation detection unit 502. Therefore, the ISS method has a higher resolution of a radiographic image obtained by imaging, and the amount of visible light received by the radiation detection unit 502 is larger than that of the PSS method. Therefore, the sensitivity of the radiation detector 66 (electronic cassette 20) can be improved in the ISS system than in the PSS system.

The scintillator 500 may be made of a material such as CsI: Tl, CsI: Na (sodium activated cesium iodide), GOS (Gd ₂ O ₂ S: Tb), or the like.

FIG. 17B illustrates, as an example, a case where a scintillator 500 including a columnar crystal region is formed by vapor-depositing a material including CsI on a vapor deposition substrate 504 corresponding to the support substrate 144 described above. Therefore, the scintillator panel 62 is formed by the vapor deposition substrate 504 and the scintillator 500 (see FIG. 17A).

Specifically, in the scintillator 500 of FIG. 17B, a columnar crystal region composed of columnar crystals 500a is formed on the irradiation surface 44 side (radiation detection unit 502 side) on which the radiation 16 is incident, and on the opposite side of the irradiation surface 44 side. A non-columnar crystal region composed of the non-columnar crystal 500b is formed. The columnar crystal 500a corresponds to the columnar crystal structure 148 (see FIGS. 4A, 4B, and 10A to 16B), and the non-columnar crystal 500b corresponds to the non-columnar crystal portion 146. The vapor deposition substrate 504 is preferably made of a material having high heat resistance. For example, aluminum (Al) is preferable from the viewpoint of low cost. In the scintillator 500, the average diameter of the columnar crystals 500a is approximately uniform along the longitudinal direction of the columnar crystals 500a.

As described above, the scintillator 500 has a structure formed of a columnar crystal region (columnar crystal 500a) and a non-columnar crystal region (noncolumnar crystal 500b), and a columnar crystal 500a that can emit light with high efficiency. The crystal region is disposed on the radiation detection unit 502 side. Therefore, visible light generated by the scintillator 500 travels through the columnar crystal 500 a and is emitted to the radiation detection unit 502. As a result, diffusion of visible light emitted toward the radiation detection unit 502 side is suppressed, and blurring of the radiation image detected by the electronic cassette 20 is suppressed. Further, the visible light reaching the deep part (non-columnar crystal region) of the scintillator 500 is also reflected by the non-columnar crystal 500b toward the radiation detection unit 502, so that the amount of visible light incident on the radiation detection unit 502 (in the scintillator 500) (Detection efficiency of emitted visible light) can also be improved.

Note that if the thickness of the columnar crystal region located on the irradiation surface 44 side of the scintillator 500 is t1, and the thickness of the non-columnar crystal region located on the vapor deposition substrate 504 side of the scintillator 500 is t2, the interval between t1 and t2 , 0.01 ≦ (t2 / t1) ≦ 0.25 is preferably satisfied.

Thus, when the thickness t1 of the columnar crystal region and the thickness t2 of the non-columnar crystal region satisfy the above relationship, a region (columnar crystal region) that has high luminous efficiency and prevents the diffusion of visible light, and visible light The ratio along the thickness direction of the scintillator 500 to the region that reflects the light (non-columnar crystal region) is a suitable range, the light emission efficiency of the scintillator 500, the detection efficiency of visible light emitted by the scintillator 500, and the radiation image Improve the resolution.

Note that, if the thickness t2 of the non-columnar crystal region is too thick, a region with low light emission efficiency is increased and the sensitivity of the electronic cassette 20 is decreased. Therefore, (t2 / t1) is in the range of 0.02 or more and 0.1 or less. It is more preferable that

In the above description, the scintillator 500 having a structure in which a columnar crystal region and a non-columnar crystal region are continuously formed has been described. For example, instead of the noncolumnar crystal region, a light reflection made of Al or the like is used. A layer may be provided so that only the columnar crystal region is formed, or another configuration may be used.

The radiation detection unit 502 detects visible light emitted from the light emission side (columnar crystal 500a) of the scintillator 500. In the side view of FIG. 17A, the radiation detection unit 502 is applied to the irradiation surface 44 along the incident direction of the radiation 16. On the other hand, the insulating substrate 508, the TFT layer 510, and the photoelectric conversion portion 512 are sequentially stacked. A planarization layer 514 is formed on the bottom surface of the TFT layer 510 so as to cover the photoelectric conversion portion 512.

In addition, the radiation detection unit 502 includes a plurality of pixel units 520 each including a photoelectric conversion unit 512 including a photodiode (PD: Photo Diode), a storage capacitor 516, and a TFT 518 in a matrix on the insulating substrate 508 in a plan view. The TFT active matrix substrate (hereinafter also referred to as a TFT substrate) is formed.

Note that the TFT 518 corresponds to the above-described TFT 72 (see FIG. 7), and the photoelectric conversion unit 512 and the storage capacitor 516 correspond to the pixel 160.

The photoelectric conversion unit 512 is configured by arranging a photoelectric conversion film 512c between a lower electrode 512a on the scintillator 500 side and an upper electrode 512b on the TFT layer 510 side. The photoelectric conversion film 512c absorbs visible light emitted from the scintillator 500 and generates a charge corresponding to the absorbed visible light.

Since the lower electrode 512a needs to make visible light emitted from the scintillator 500 incident on the photoelectric conversion film 512c, the lower electrode 512a is preferably formed of a conductive material that is transparent at least with respect to the emission wavelength of the scintillator 500. Specifically, it is preferable to use a transparent conductive oxide (TCO) having a high visible light transmittance and a low resistance value.

Note that although a metal thin film such as Au can be used as the lower electrode 512a, a resistance value tends to increase when an optical transmittance of 90% or more is obtained, so that the TCO is preferable. For example, a process using ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum doped Zinc Oxide), FTO (Fluorine doped Tin Oxide), SnO ₂ , TiO ₂ , ZnO ₂ or the like is preferable. ITO is most preferable from the viewpoints of stability, low resistance, and transparency. Further, the lower electrode 512a may have a single configuration common to all the pixel portions 520, or may be divided for each pixel portion 520.

Further, the photoelectric conversion film 512c may be formed of a material that absorbs visible light and generates electric charge, and for example, amorphous silicon (a-Si), an organic photoelectric conversion material (OPC), or the like can be used. When the photoelectric conversion film 512c is made of amorphous silicon, visible light emitted from the scintillator 500 can be absorbed over a wide wavelength range. However, the formation of the photoelectric conversion film 512c made of amorphous silicon requires vapor deposition. When the insulating substrate 508 is made of a synthetic resin, the heat resistance of the insulating substrate 508 needs to be considered.

On the other hand, when the photoelectric conversion film 512c is formed of a material containing an organic photoelectric conversion material, an absorption spectrum that exhibits high absorption mainly in the visible light region is obtained. Therefore, in the photoelectric conversion film 512c, visible light emitted from the scintillator 500 is obtained. Absorption of electromagnetic waves other than light is almost eliminated. As a result, noise generated by absorption of radiation 16 such as X-rays and γ-rays in the photoelectric conversion film 512c can be suppressed.

In addition, the photoelectric conversion film 512c made of an organic photoelectric conversion material can be formed by depositing an organic photoelectric conversion material on an object to be formed using a droplet discharge head such as an inkjet head. Heat resistance to the body is not required. For this reason, in the eighth modification, the photoelectric conversion film 512c is formed of an organic photoelectric conversion material.

Furthermore, when the photoelectric conversion film 512c is made of an organic photoelectric conversion material, the radiation 16 is hardly absorbed by the photoelectric conversion film 512c. Therefore, in the ISS system in which the radiation detection unit 502 is arranged so that the radiation 16 is transmitted, radiation detection is performed. Attenuation of the radiation 16 transmitted through the part 502 can be suppressed, and a decrease in sensitivity to the radiation 16 can be suppressed. Therefore, it is particularly suitable for the ISS system to configure the photoelectric conversion film 512c with an organic photoelectric conversion material.

The organic photoelectric conversion material constituting the photoelectric conversion film 512c is preferably as close as possible to the emission peak wavelength of the scintillator 500 in order to absorb the visible light emitted from the scintillator 500 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator 500, but if the difference between the two is small, the visible light emitted from the scintillator 500 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 of the scintillator 500 with respect to the radiation 16 is preferably within 10 nm, and more preferably within 5 nm.

Examples of organic photoelectric conversion materials that can satisfy such conditions include quinacridone organic compounds and phthalocyanine 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 500, the difference between the peak wavelengths can be within 5 nm. Thus, the amount of charge generated in the photoelectric conversion film 512c can be substantially maximized.

Next, the photoelectric conversion film 512c applicable to the radiation detector 66 will be described more specifically.

The electromagnetic wave absorption / photoelectric conversion site in the radiation detector 66 is an organic layer including an upper electrode 512b and a lower electrode 512a, and a photoelectric conversion film 512c sandwiched between the upper electrode 512b and the lower electrode 512a. 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. It can be formed by stacking or mixing improved parts.

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

Since the materials applicable as the organic p-type semiconductor and the organic n-type semiconductor and the configuration of the photoelectric conversion film 512c are described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

In addition, the photoelectric conversion unit 512 only needs to include at least the upper electrode 512b, the lower electrode 512a, and the photoelectric conversion film 512c. However, in order to suppress an increase in dark current, at least one of an electron blocking film and a hole blocking film is required. It is preferable to provide these, and it is more preferable to provide both.

The electron blocking film can be provided between the upper electrode 512b and the photoelectric conversion film 512c. When a bias voltage is applied between the upper electrode 512b and the lower electrode 512a, the electron blocking film is applied from the upper electrode 512b to the photoelectric conversion film 512c. An increase in dark current due to injection of electrons can be suppressed. 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 photoelectric conversion film 512c, etc., and the electron function is 1.3 eV or more from the work function (Wf) of the adjacent electrode material. A material having a large affinity (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoelectric conversion film 512c is 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, particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in the photoelectric conversion efficiency of the photoelectric conversion unit 512. Is from 50 nm to 100 nm.

The hole blocking film can be provided between the photoelectric conversion film 512c and the lower electrode 512a, and when a bias voltage is applied between the upper electrode 512b and the lower electrode 512a, the lower electrode 512a to the photoelectric conversion film 512c. It is possible to suppress the increase of dark current due to injection of holes into the substrate. An electron-accepting organic material can be used for the hole blocking film. 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 photoelectric conversion film 512c, etc., and 1.3 eV or more from the work function (Wf) of the material of the adjacent electrode. Those having a large ionization potential (Ip) and an Ea equivalent to or higher than the electron affinity (Ea) of the material of the adjacent photoelectric conversion film 512c are 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.

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 the photoelectric conversion efficiency of the photoelectric conversion unit 512. Is from 50 nm to 100 nm.

In the case where the bias voltage is set so that holes move to the lower electrode 512a and electrons move to the upper electrode 512b among the charges generated in the photoelectric conversion film 512c, the position of the electron blocking film and the holes are set. The position of the blocking film may be reversed. Moreover, it is not essential to provide both the electron blocking film and the hole blocking film, and if any of them is provided, a certain degree of dark current suppressing effect can be obtained.

In the TFT 518 of the TFT layer 510, a gate electrode, a gate insulating film, and an active layer (channel layer) are stacked, and a source electrode and a drain electrode are formed on the active layer at a predetermined interval. The active layer can be formed of any of amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, etc., but the material that can form the active layer is not limited to these. Absent.

As an amorphous oxide capable of forming an active layer, for example, an oxide containing at least one of In, Ga, and Zn (for example, an In—O system) is preferable, and at least one of In, Ga, and Zn is used. An oxide containing two (eg, In—Zn—O, In—Ga—O, and Ga—Zn—O) is more preferable, and an oxide containing In, Ga, and Zn is 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 in particular, InGaZnO. ₄ is more preferable. Note that the amorphous oxide capable of forming the active layer is not limited to these.

Moreover, examples of the organic semiconductor material capable of forming the active layer include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. The configuration of the phthalocyanine compound is described in detail in Japanese Patent Application Laid-Open No. 2009-212389, and thus the description thereof is omitted.

If the active layer of the TFT 518 is formed of any one of an amorphous oxide, an organic semiconductor material, a carbon nanotube, and the like, the radiation 16 such as X-rays is not absorbed, or even if it is absorbed, the amount is extremely small. The generation of noise in the radiation detection unit 502 can be effectively suppressed.

Further, when the active layer is formed of carbon nanotubes, the switching speed of the TFT 518 can be increased, and the degree of light absorption in the visible light region in the TFT 518 can be reduced. In addition, when the active layer is formed of carbon nanotubes, the performance of the TFT 518 is remarkably deteriorated only by mixing a very small amount of metallic impurities into the active layer. Therefore, it must be used for forming the active layer.

Moreover, since the film | membrane formed with the organic photoelectric conversion material and the film | membrane formed with the organic-semiconductor material have sufficient flexibility, the photoelectric conversion film 512c formed with the organic photoelectric conversion material, and an active layer are used. If the configuration is combined with a TFT 518 formed of an organic semiconductor material, it is not always necessary to increase the rigidity of the radiation detection unit 502 in which the weight of the body of the subject 14 is added as a load.

Further, the insulating substrate 508 may be any substrate that has optical transparency and little radiation 16 absorption. Here, both the amorphous oxide constituting the active layer of the TFT 518 and the organic photoelectric conversion material constituting the photoelectric conversion film 512c of the photoelectric conversion portion 512 can be formed at a low temperature. Therefore, the insulating substrate 508 is not limited to a highly heat-resistant substrate such as a semiconductor substrate, a quartz substrate, or a glass substrate, and a flexible substrate made of synthetic resin, aramid, or bio-nanofiber can also be used. Specifically, flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), etc. A conductive substrate can be used. By using such a flexible substrate made of synthetic resin, it is possible to reduce the weight, which is advantageous for carrying around, for example. Note that the insulating substrate 508 includes an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be provided.

In addition, since aramid can be applied to a high temperature process of 200 ° C. or higher, the transparent electrode material can be cured at a high temperature to reduce resistance, and it 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 or a glass substrate, warping after production is small and it is difficult to break. In addition, aramid can make a substrate thinner than a glass substrate or the like. Note that the insulating substrate 508 may be formed by stacking an ultrathin glass substrate and aramid.

In addition, the bionanofiber is a composite of cellulose microfibril bundle (bacterial cellulose) produced by bacteria (acetobacterium, Xylinum) and 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 acrylic resin or 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% to 70% of the fiber. Bionanofiber has a low coefficient of thermal expansion (3-7 ppm) comparable to that of silicon crystals, and is as strong as steel (460 MPa), highly elastic (30 GPa), and flexible. Compared to glass substrates, etc. Thus, the insulating substrate 508 can be thinned.

When a glass substrate is used as the insulating substrate 508, the thickness of the radiation detector 502 (TFT substrate) as a whole is about 0.7 mm, for example, but in the eighth modification, the electronic cassette 20 is considered to be thin. As the insulating substrate 508, a thin substrate made of a light-transmitting synthetic resin is used. As a result, the thickness of the radiation detection unit 502 as a whole can be reduced to, for example, about 0.1 mm, and the radiation detection unit 502 can be flexible. Further, by providing the radiation detection unit 502 with flexibility, the impact resistance of the electronic cassette 20 is improved, and even when an impact is applied to the electronic cassette 20, it is difficult to be damaged. In addition, plastic resin, aramid, bionanofiber, etc. all absorb less radiation 16, and when the insulating substrate 508 is formed of these materials, the amount of radiation 16 absorbed by the insulating substrate 508 also decreases. Even if the radiation 16 is transmitted through the radiation detection unit 502 by the ISS method, a decrease in sensitivity to the radiation 16 can be suppressed.

Note that it is not essential to use a synthetic resin substrate as the insulating substrate 508 of the electronic cassette 20, and although the thickness of the electronic cassette 20 increases, a substrate made of another material such as a glass substrate is used as the insulating substrate 508. You may make it use as.

Further, a flattening layer 514 for flattening the radiation detection unit 502 is formed on the radiation detection unit 502 (TFT substrate) on the side opposite to the arrival direction of the radiation 16 (on the scintillator 500 side).

In the eighth modification, the radiation detector 66 may be configured as follows.

(1) The photoelectric conversion part 512 including PD may be formed of an organic photoelectric conversion material, and the TFT layer 510 may be formed using a CMOS sensor. In this case, since only the PD is made of an organic material, the TFT layer 510 including the CMOS sensor may not have flexibility. Since the photoelectric conversion unit 512 made of an organic photoelectric conversion material and the CMOS sensor are described in Japanese Patent Application Laid-Open No. 2009-212377, detailed description thereof is omitted.

(2) The photoelectric conversion unit 512 including the PD may be formed of an organic photoelectric conversion material, and the flexible TFT layer 510 may be realized by a CMOS circuit including a TFT made of an organic material. In this case, pentacene may be adopted as the material of the p-type organic semiconductor used in the CMOS circuit, and copper fluoride phthalocyanine (F ₁₆ CuPc) may be adopted as the material of the n-type organic semiconductor. As a result, a flexible TFT layer 510 that can have a smaller bending radius can be realized. In addition, by configuring the TFT layer 510 in this way, the gate insulating film can be significantly thinned, and the driving voltage can be lowered. Furthermore, the gate insulating film, the semiconductor, and each electrode can be manufactured at room temperature or 100 ° C. or lower. Furthermore, a CMOS circuit can be directly formed over the flexible insulating substrate 508. In addition, a TFT made of an organic material can be miniaturized by a manufacturing process in accordance with a scaling law. Note that the insulating substrate 508 can be realized by applying a polyimide precursor on a thin polyimide substrate by spin coating and heating, so that the polyimide precursor is changed to polyimide, so that a flat substrate without unevenness can be realized. it can.

(3) Applying self-alignment placement technology (Fluidic Self-Assembly method) to place multiple device blocks of micron order at specified positions on the substrate, insulating PD and TFT made of crystalline Si from resin substrate You may arrange | position on the board | substrate 508. FIG. In this case, PDs and TFTs as micro device blocks of micron order are fabricated in advance on another substrate and then separated from the substrate, and the PDs and TFTs are dispersed on an insulating substrate 508 as a target substrate in a liquid. And place statistically. The insulating substrate 508 is processed in advance to be adapted to the device block, and the device block can be selectively disposed on the insulating substrate 508. Therefore, the optimum device block (PD and TFT) made of the optimum material can be integrated on the optimum substrate (insulating substrate 508), and the PD and the insulating substrate 508 (resin substrate) which are not crystals can be integrated. It becomes possible to integrate TFTs.

[Another configuration example of this embodiment]
It should be noted that the electronic cassette 20 according to the present embodiment is not limited to the above description, and it is needless to say that the following configuration may be adopted or used together.

In the above descriptions, as specific examples of the contact mechanism for contacting or separating the scintillator 150 and the radiation conversion panel 64, the

airbags

118, 240, 274, the storage bag 190, the spring member 214, the piezoelectric element 220, and the cam 254 are used. The case where is used has been described. The contact mechanism is not limited to the above specific example, and any configuration may be used as long as it can dynamically contact or separate the scintillator 150 and the radiation conversion panel 64.

For example, in the present embodiment, the first modified example, and the seventh modified example, the inert gas generated by the inflator 120 is supplied to the

airbags

118, 240, 274 so that the

airbags

118, 240, 274 are It is inflated. Instead, an air cylinder capable of replenishing air from the outside is mounted on or connected to the electronic cassette 20, and air is supplied from the air cylinder to the

airbags

118, 240, and 274 by valve opening / closing control. 240, 274 may be inflated. Alternatively, compressed air may be supplied from the air pump (compressor) to the

airbags

118, 240, and 274 to inflate the

airbags

118, 240, and 274. In these examples, in order to contract the

airbags

118, 240, and 274, the

airbag

118, 240, and 274 are discharged through holes (not shown) or the air pump is driven to drive the airbag 118. , 240, 274 may be discharged.

Further, in the drawings of the present embodiment and the first to seventh modifications, when the scintillator 150 and the radiation conversion panel 64 are separated from each other, they are illustrated as being completely separated (non-contact state). The present embodiment and the first to seventh modifications are not limited to those shown in the drawings. By stopping contact control between the scintillator 150 and the radiation conversion panel 64 by the contact mechanism described above, The contact pressure with the radiation conversion panel 64 may be lower than the contact pressure when the scintillator 150 and the radiation conversion panel 64 are pressed, or may be in a state where almost no pressure is applied. In this case, the scintillator 150 and the radiation conversion panel 64 cannot be completely separated from each other, but it is possible to obtain the respective effects obtained by stopping the contact control of the contact mechanism with respect to the scintillator 150 and the radiation conversion panel 64. .

Furthermore, in the present embodiment and the first to seventh modifications, the contact control with respect to the scintillator 150 and the radiation conversion panel 64 when an impact is applied to the electronic cassette 20 from the outside has been mainly described. The present embodiment and the first to seventh modifications are not limited to these descriptions. The contact mechanism contacts the scintillator 150 and the radiation conversion panel 64 based on the order information before photographing the subject 14. On the other hand, after photographing the subject 14, the scintillator 150 and the radiation conversion panel 64 may be separated from each other, or the contact pressure between the scintillator 150 and the radiation conversion panel 64 may be reduced. Since the scintillator 150 and the radiation conversion panel 64 are pressed against each other only during imaging with a low possibility of receiving an impact from the outside, even in this case, each effect related to contact control between the scintillator 150 and the radiation conversion panel 64 is achieved. Can be obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

Claims

In a radiation imaging apparatus (20) having a radiation detector (66) provided with a scintillator (150) for converting radiation (16) into visible light and a radiation conversion panel (64) for converting the visible light into an electrical signal. ,
A contact mechanism (118, 190, 214, 220, 240, 254, 274) for bringing the scintillator (150) into contact with the radiation conversion panel (64);
A movement detector (56, 58) for detecting movement of the radiation imaging apparatus (20);
At least when the radiation (16) is applied to the radiation detector (66), the contact mechanism (118, 190, 214, 220, 240) is brought into contact with the scintillator (150) and the radiation conversion panel (64). 254, 274), while the contact mechanism (118) when a physical quantity related to the movement of the radiation imaging apparatus (20) detected by the movement detector (56, 58) exceeds a predetermined threshold. , 190, 214, 220, 240, 254, 274), a contact control unit (110) for stopping contact control between the scintillator (150) and the radiation conversion panel (64);
A radiation imaging apparatus, further comprising:
Device (20) according to claim 1,
The scintillator (150) can convert the radiation (16) into the visible light on a support substrate (144) that supports the scintillator (150) along a direction substantially orthogonal to the support substrate (144). A columnar crystal (148) is formed by vapor deposition,
The contact mechanism (118, 190, 214, 220, 240, 254, 274) performs contact control between the tip portion of the columnar crystal (148) and the radiation conversion panel (64). apparatus.
Device (20) according to claim 2,
The radiation detector (66), the contact mechanism (118, 190, 214, 220, 240, 254, 274), the movement detection unit (56, 58), and the contact control unit (110) are accommodated, and the radiation (16) further has a portable casing (40) that is transmissive.
In the casing (40), the support substrate (144), the scintillator (150), and the radiation conversion panel (64) are sequentially arranged along the thickness direction of the casing (40).
Radiography, wherein the surface of the housing (40) facing the support substrate (144) or the radiation conversion panel (64) is an irradiation surface (44) irradiated with the radiation (16). apparatus.
Device (20) according to claim 3,
The movement detection unit (56, 58) is configured to detect the acceleration of the radiation imaging apparatus (20) or the radiation imaging apparatus (56) from the subject (14) in contact with the irradiation surface (44). 20) a pressure sensor (58) for detecting the pressure applied to
The contact control unit (110)
When the physical quantity related to the acceleration or the pressure is less than the threshold value, the tip of the columnar crystal (148) is controlled by controlling the contact mechanism (118, 190, 214, 220, 240, 254, 274). Bringing the portion into contact with the radiation conversion panel (64);
On the other hand, when the physical quantity exceeds the threshold value, the tip portion of the columnar crystal (148) by the contact mechanism (118, 190, 214, 220, 240, 254, 274) and the radiation conversion panel (64) A radiation imaging apparatus characterized by stopping contact control with the device.
Device (20) according to claim 4,
The contact mechanism (118, 240, 274) expands or contracts along the thickness direction of the housing (40), so that the tip portion of the columnar crystal (148) and the radiation conversion panel (64) are connected. An airbag that performs contact control;
The radiation imaging apparatus (20) is accommodated in the housing (40), and an inert gas is fed into the airbag (118, 240, 274) to reduce the thickness of the airbag (118, 240, 274). A radiation imaging apparatus further comprising an inflator (120) that expands in a direction.
Device (20) according to claim 5,
In a plan view, the scintillator (150) is formed inside the support substrate (144) and the radiation conversion panel (64), and the airbag (118, 240, 274) is connected to the scintillator (150). ) Around the outer edge of the support substrate (144) or the outer edge of the radiation conversion panel (64).
When the contact control unit (110) instructs to separate the distal end portion of the columnar crystal (148) from the radiation conversion panel (64), the inflator (120) causes the inert gas to flow into the airbag ( 118, 240, 274)
The airbag (118, 240, 274) expands in the thickness direction between the outer edge portion of the support substrate (144) and the outer edge portion of the radiation conversion panel (64), so that the columnar crystals ( 148) and the radiation conversion panel (64) are separated from each other.
Device (20) according to claim 5,
The airbag (118, 240, 274) is inserted between the support substrate (144) and a surface of the housing (40) facing the support substrate (144), or the radiation conversion is performed. Inserted between the panel (64) and the surface of the housing (40) facing the radiation conversion panel (64),
When the contact control unit (110) instructs to stop the contact control between the tip portion of the columnar crystal (148) and the radiation conversion panel (64), the airbag (118, 240, 274) A radiation imaging apparatus characterized in that an inert gas is discharged and contracted in the thickness direction to separate the tip portion of the columnar crystal (148) from the radiation conversion panel (64).
Device (20) according to claim 4,
The contact mechanism (190) causes the inside of the chamber (192) containing the radiation detector (66) to be in a negative pressure state and contracts along the thickness direction, thereby leading the tip portion of the columnar crystal (148). And the radiation conversion panel (64), while the inside of the chamber (192) is in an atmospheric pressure state and expands along the thickness direction, the tip portion of the columnar crystal (148) A radiation imaging apparatus, wherein the radiation imaging apparatus is a housing bag for separating the radiation conversion panel (64).
Device (20) according to claim 8,
A leak valve (196) disposed in a passage (194) communicating with the containing bag (190);
When the contact control unit (110) instructs the tip of the columnar crystal (148) to come into contact with the radiation conversion panel (64), the containing bag (190) is negative in the chamber (192). In addition to the pressure state, the leak valve (196) is closed to prevent air from entering the chamber (192) through the passage (194),
On the other hand, when the contact control unit (110) instructs to stop the contact control between the tip portion of the columnar crystal (148) and the radiation conversion panel (64), the leak valve (196) is opened. By entering the state, the radiographic apparatus is characterized by causing the air to enter the chamber (192) through the passage (194) to bring the chamber (192) into an atmospheric pressure state.
Device (20) according to claim 4,
The contact mechanism (214) contracts along the thickness direction to bring the tip portion of the columnar crystal (148) into contact with the radiation conversion panel (64), while along the thickness direction. A radiation imaging apparatus characterized by being a spring member that controls contact between the distal end portion of the columnar crystal (148) and the radiation conversion panel (64) by extending.
Device (20) according to claim 10,
The spring member (214) is
Between the top plate (132) and the bottom plate (140) on the irradiation surface (44) side of the housing (40) and disposed near the radiation detector (66);
Alternatively, the radiation imaging apparatus is disposed between an outer edge portion of the radiation conversion panel (64) and an outer edge portion of the support substrate (144).
Device (20) according to claim 11,
One end of the spring member (214) is fixed to the outer edge of the top plate (132) or the radiation conversion panel (64), and the other end of the spring member (214) is fixed to the bottom plate (140). ) Or a locking member (212) disposed on the outer edge of the support substrate (144),
When the contact control unit (110) instructs the tip of the columnar crystal (148) to contact the radiation conversion panel (64), the lock member (212) causes the spring member (214) to Shrink in the thickness direction,
On the other hand, when the contact control unit (110) instructs to stop the contact control between the tip of the columnar crystal (148) and the radiation conversion panel (64), the lock member (212) The radiographic apparatus characterized by releasing the locked state with respect to the member (214) and extending the spring member (214) in the thickness direction.
Device (20) according to claim 4,
The contact mechanism (220) contracts along the thickness direction to bring the tip of the columnar crystal (148) into contact with the radiation conversion panel (64), while along the thickness direction. A radiographic apparatus characterized by being a piezoelectric element that stops contact control between the distal end portion of the columnar crystal (148) and the radiation conversion panel (64) by stretching.
Device (20) according to claim 13,
The piezoelectric element (220)
Whether the casing (40) is disposed between the top plate (132) on the irradiation surface (44) side and the bottom plate (140) and in the vicinity of the radiation detector (66). ,
Alternatively, the radiation imaging apparatus is disposed between an outer edge portion of the radiation conversion panel (64) and an outer edge portion of the support substrate (144).
Device (20) according to claim 4,
The contact mechanism (254) is a cam that controls contact between the distal end portion of the columnar crystal (148) and the radiation conversion panel (64) by rotating about a rotation axis (252). Radiation imaging device.
The device (20) according to any one of claims 1 to 15,
The contact control unit (110) includes the scintillator (150) and the radiation conversion panel (64) when the radiation source (30) that outputs the radiation (16) prepares to irradiate the radiation (16). The radiographic apparatus is characterized in that the contact mechanism (118, 190, 214, 220, 240, 254, 274) is controlled so as to contact with each other.
Device (20) according to any one of the preceding claims,
The contact control unit (110) is configured to transmit the radiation (16) to the radiation detector (66) via the subject (14) based on order information relating to irradiation of the radiation (16) to the subject (14). The contact mechanism (118, 190, 214, 220, 240, 254, 274) is controlled to bring the scintillator (150) and the radiation conversion panel (64) into contact with each other, The contact mechanism (118, 190, 214, 220, 240, 254, 274) is controlled so as to stop the contact control between the scintillator (150) and the radiation conversion panel (64) after irradiation with radiation (16). A radiographic apparatus characterized by that.