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WO2014050862A1 - Dispositif de détection d'image radiographique - Google Patents

Dispositif de détection d'image radiographique Download PDF

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Publication number
WO2014050862A1
WO2014050862A1 PCT/JP2013/075858 JP2013075858W WO2014050862A1 WO 2014050862 A1 WO2014050862 A1 WO 2014050862A1 JP 2013075858 W JP2013075858 W JP 2013075858W WO 2014050862 A1 WO2014050862 A1 WO 2014050862A1
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WO
WIPO (PCT)
Prior art keywords
photoelectric conversion
image detection
layer
conversion panel
detection apparatus
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2013/075858
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English (en)
Japanese (ja)
Inventor
成行　書史
敏之 鍋田
中津川　晴康
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Fujifilm Corp
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Fujifilm Corp
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Filing date
Publication date
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Publication of WO2014050862A1 publication Critical patent/WO2014050862A1/fr
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/20—Measuring radiation intensity with scintillation detectors
    • G01T1/2018—Scintillation-photodiode combinations
    • G01T1/20187—Position of the scintillator with respect to the photodiode, e.g. photodiode surrounding the crystal, the crystal surrounding the photodiode, shape or size of the scintillator
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/20—Measuring radiation intensity with scintillation detectors
    • G01T1/202—Measuring radiation intensity with scintillation detectors the detector being a crystal
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4283—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by a detector unit being housed in a cassette

Definitions

  • the present invention relates to a radiological image detection apparatus used for radiography.
  • This radiation image detection apparatus includes a direct conversion system that directly converts radiation into electric charges and an indirect conversion system that converts radiation once into visible light and converts the visible light into electric charge.
  • the indirect conversion type radiation image detection apparatus has a scintillator (phosphor layer) that absorbs radiation and converts it into visible light, and a photoelectric conversion panel that detects visible light and converts it into electric charge.
  • a scintillator cesium iodide (CsI) or gadolinium oxide sulfur (GOS) is used.
  • CsI cesium iodide
  • GOS gadolinium oxide sulfur
  • the photoelectric conversion panel thin film transistors and photodiodes are arranged in a matrix on the surface of a glass insulating substrate.
  • CsI is higher in manufacturing cost than GOS, but has high conversion efficiency from radiation to visible light. Further, CsI has a columnar crystal structure and improves the S / N ratio of image data due to the light guide effect. Therefore, CsI is used as a scintillator of a radiographic image detection apparatus especially for high end.
  • a pasting method and a direct vapor deposition method are known.
  • the deposition substrate on which the scintillator is deposited and the photoelectric conversion panel are pasted via an adhesive layer so that the scintillator faces the photoelectric conversion panel.
  • the tip of the CsI columnar crystal is close to the photoelectric conversion panel, and visible light emitted from the tip is efficiently incident on the photoelectric conversion panel, so that a high-resolution radiation image can be obtained.
  • the pasting method uses a vapor deposition substrate, so that the number of manufacturing steps is large and the cost is high.
  • the scintillator is directly vapor deposited on the photoelectric conversion panel. Since this direct vapor deposition method does not require a vapor deposition substrate, the number of manufacturing steps is small and the cost is low. In this direct vapor deposition method, since the tip of the CsI columnar crystal is disposed on the opposite side of the photoelectric conversion panel, the image quality of the radiation image is slightly inferior to that of the pasting method, but the scintillator is formed of GOS. Better than the case. For this reason, the direct vapor deposition method has a good balance between performance and cost.
  • the photoelectric conversion panel is arranged on the radiation source side, and the radiation emitted from the radiation source is passed through the photoelectric conversion panel.
  • ISS Radiation Side Sampling
  • JP2012-105879A corresponding US2012 / 0126124A1
  • JP2001-330677A JP2001-330677A
  • the photoelectric conversion panel is disposed close to the portion of the casing that comes into contact with the subject. Therefore, the photoelectric conversion panel is easily bent due to the load from the subject. There is a problem that destruction occurs.
  • monocoque structures have been widely used for housings, but the monocoque structure is lightweight, but has low load resistance, so it is easy to transmit the load from the subject to the photoelectric conversion panel. It will bend more.
  • An object of the present invention is to provide an ISS type radiation image detection apparatus capable of improving the load resistance of a photoelectric conversion panel.
  • the radiation image detection apparatus of the present invention includes a photoelectric conversion panel, a reinforcing substrate, and a scintillator.
  • the photoelectric conversion panel a plurality of pixels that perform photoelectric conversion are arranged on a glass insulating substrate having a thickness of 0.5 mm or less.
  • the reinforcing substrate is affixed to the radiation incident side of the photoelectric conversion panel or the opposite side to the radiation incident side.
  • the scintillator is disposed on the opposite side of the photoelectric conversion panel from the radiation incident side, and contains cesium iodide deposited on the photoelectric conversion panel or the reinforcing substrate.
  • the scintillator preferably has a non-columnar crystal layer and a plurality of columnar crystals formed on the non-columnar crystal layer, and the non-columnar crystal layer is preferably in close contact with the photoelectric conversion panel or the reinforcing substrate.
  • the reinforcing substrate is preferably attached to the radiation incident side of the photoelectric conversion panel via an adhesive layer, and the scintillator is preferably directly deposited on the surface opposite to the radiation incident side of the photoelectric conversion panel.
  • the reinforcing substrate is preferably formed of any one of resin, soda glass, and aluminum.
  • the reinforcing substrate is attached to the opposite side of the photoelectric conversion panel from the radiation incident side via an adhesive layer, and the scintillator is directly deposited on the surface of the reinforcing substrate opposite to the radiation incident side. Also good.
  • the reinforcing substrate is preferably formed of an OPS film or soda glass.
  • the pixel preferably includes a photodiode that converts visible light into electric charge and a thin film transistor for reading out electric charge generated by the photodiode.
  • the semiconductor layer of the photodiode and the active layer of the thin film transistor are formed of silicon and the insulating substrate is formed of alkali-free glass.
  • the semiconductor layer of the photodiode is formed of an organic photoelectric conversion material
  • the active layer of the thin film transistor is formed of an oxide semiconductor
  • the insulating substrate is formed of soda glass.
  • mammography imaging can be performed by using X-rays having an energy in the range of 37 KeV to 50 KeV.
  • the insulating substrate preferably has a thickness of 0.05 mm to 0.5 mm.
  • the photoelectric conversion panel, the reinforcing substrate, and the scintillator are preferably housed in a monocoque housing.
  • the reinforcing substrate is attached to the radiation incident side of the photoelectric conversion panel having a glass insulating substrate having a thickness of 0.5 mm or less, or the opposite side to the radiation incident side.
  • the scintillator is arranged on the side opposite to the radiation incident side of the photoelectric conversion panel, the photoelectric conversion panel is reinforced by the reinforcing substrate, and the load resistance of the photoelectric conversion panel is improved.
  • FIG. 1st Embodiment It is a partially broken perspective view of the X-ray image detection apparatus of 1st Embodiment. It is sectional drawing of an X-ray image detection apparatus. It is sectional drawing of FPD. It is a circuit diagram which shows the structure of a photoelectric conversion panel. It is explanatory drawing which shows the use condition of an X-ray image detection apparatus. It is a graph which shows the relationship between the tensile stress of glass, and a curvature radius. It is a top view of the reinforcement board
  • an X-ray image detection apparatus 10 includes a flat panel detector (FPD) 11, a support substrate 12, a control unit 13, and a casing 14 that accommodates these.
  • the housing 14 has a monocoque structure integrally formed of a carbon fiber reinforced resin (carbon fiber) having high X-ray XR permeability, light weight, and high durability.
  • An opening (not shown) is formed on one side surface of the casing 14, and the FPD 11, the circuit board 12, and the control unit 13 are inserted into the casing 14 from the opening when the X-ray image detection apparatus 10 is manufactured. . After these insertions, a lid (not shown) is attached so as to close the opening.
  • the upper surface 14a of the housing 14 is an irradiation surface irradiated with X-rays XR emitted from an X-ray source 60 (see FIG. 5) and transmitted through a subject (patient) 61 (see FIG. 5).
  • An alignment mark (not shown) is provided on the irradiation surface 14a in order to align the X-ray source 60 and the subject 61.
  • the X-ray image detection apparatus 10 has the same size as a conventional X-ray film cassette and can be used in place of the X-ray film cassette, and is therefore referred to as an electronic cassette.
  • the FPD 11 and the support substrate 12 are arranged in order from the irradiation surface 14 a side irradiated with the X-ray XR during imaging.
  • the support substrate 12 supports a circuit substrate 25 (see FIG. 2) and is fixed to the housing 14.
  • the control unit 13 is disposed on the short one end side in the housing 14.
  • the control unit 13 accommodates a microcomputer and a battery (both not shown). This microcomputer communicates with a console (not shown) connected to the X-ray source 60 via a wired or wireless communication unit (not shown) to control the operation of the FPD 11.
  • the FPD 11 includes a scintillator 20 that converts X-rays XR into visible light, and a photoelectric conversion panel 21 that converts the visible light into electric charge.
  • the X-ray image detection apparatus 10 is an ISS (Irradiation Side Sampling) type, and is arranged in the order of the photoelectric conversion panel 21 and the scintillator 20 from the side (irradiation surface 14a side) on which X-ray XR is incident during imaging.
  • the scintillator 20 absorbs the X-ray XR transmitted through the photoelectric conversion panel 21 and generates visible light.
  • the photoelectric conversion panel 21 receives visible light emitted from the scintillator 20, performs photoelectric conversion, and generates electric charges.
  • a reinforcing substrate 22 is attached to the X-ray incident side of the photoelectric conversion panel 21 via a first adhesive layer 22a made of an epoxy resin or the like.
  • the X-ray incident side of the reinforcing substrate 22 is attached to the irradiation surface 14a side of the housing 14 via a second adhesive layer 22b made of epoxy resin or the like.
  • the reinforcing substrate 22 is formed of a resin such as polyimide or PET (Polyethylene terephthalate), and prevents the photoelectric conversion panel 21 from being bent.
  • the scintillator 20 is formed by evaporating thallium activated cesium iodide (CsI: Tl) on the surface 21 a of the photoelectric conversion panel 21.
  • the scintillator 20 has a plurality of columnar crystals 20a and non-columnar crystal layers 20b, and the non-columnar crystal layers 20b are formed on the photoelectric conversion panel 21 side.
  • the columnar crystal 20a is a crystal grown from the non-columnar crystal layer 20b, and has a tip portion 20c on the opposite side to the non-columnar crystal layer 20b.
  • a plurality of columnar crystals 20a are formed on the non-columnar crystal layer 20b, and each columnar crystal 20a is separated from the adjacent columnar crystal 20a via an air layer. Since the columnar crystal 20a has a refractive index of about 1.81, which is larger than the refractive index of the air layer (about 1.0), it has a light guide effect. Due to this light guiding effect, most of the visible light generated in each columnar crystal 20a propagates in the generated columnar crystal 20a and enters the photoelectric conversion panel 21 via the non-columnar crystal layer 20b.
  • the scintillator 20 is formed with a sealing film 23 for sealing the columnar crystals 20a and the non-columnar crystal layers 20b.
  • the sealing film 23 is formed of polyparaxylene having moisture resistance.
  • this polyparaxylene for example, Parylene C (trade name, manufactured by Japan Parylene Co., Ltd .; “Parylene” is a registered trademark) is used.
  • the sealing film 23 prevents the scintillator 20 from moisture.
  • a light reflecting film 24 is formed on the surface of the sealing film 23 covering the tip 20c of the columnar crystal 20a.
  • the light reflecting film 24 is formed of an aluminum film or an aluminum vapor deposition film. Visible light emitted from the tip 20c of the columnar crystal 20a is reflected by the light reflecting film 24 and returns to the columnar crystal 20a, so that the conversion efficiency of the X-ray XR into charges is improved.
  • the support substrate 12 is disposed on the side opposite to the X-ray incident side of the scintillator 20.
  • the support substrate 12 and the light reflecting film 24 face each other with an air layer interposed therebetween.
  • the support substrate 12 is fixed to the side portion 14b of the housing 14 with screws or the like.
  • a circuit board 25 is fixed to the lower surface 12a of the support substrate 12 opposite to the scintillator 20 via an adhesive or the like.
  • the circuit board 25 and the photoelectric conversion panel 21 are electrically connected via a flexible printed board 26.
  • the flexible printed circuit board 26 is connected to an external terminal 21 b provided at the end of the photoelectric conversion panel 21 by a so-called TAB (Tape Automated Bonding) bonding method.
  • the circuit board 25 includes a signal processing unit 25a that generates image data based on the voltage signal converted by the charge amplifier 26b, and an image memory 25b that stores the image data.
  • the photoelectric conversion panel 21 has a glass insulating substrate 30 and a plurality of pixels 31 arranged thereon.
  • the pixel 31 is formed by depositing silicon or the like on the insulating substrate 30.
  • silicon takes in the alkali element of the substrate during film formation and deteriorates its characteristics. For this reason, it is preferable to use non-alkali glass for the insulating substrate 30.
  • soda glass common as glass contains sodium, it is not preferable for the insulating substrate 30 of this embodiment.
  • the thickness of the insulating substrate 30 is preferably 0.5 mm or less in order to improve the X-ray XR permeability.
  • the thickness of the insulating substrate 30 is more preferably in the range of 0.05 mm to 0.5 mm. When the thickness of the insulating substrate 30 is within this range, the load resistance is improved, and even if the insulating substrate 30 is bent by the load to generate a stress, it does not easily reach the breaking stress. Since the aforementioned reinforcing substrate 22 is disposed on the X-ray incident side from the photoelectric conversion panel 21, it is preferable that the X absorption amount per unit thickness is smaller than that of the insulating substrate 30.
  • Each pixel 31 includes a thin film transistor (TFT) 32 and a photodiode (PD) 33 connected to the TFT 32.
  • the PD 33 photoelectrically converts the visible light generated by the scintillator 20 to generate charges and accumulates them.
  • the TFT 32 is a switching element for reading out charges accumulated in the PD 33.
  • the TFT 32 includes a gate electrode 32g, a source electrode 32s, a drain electrode 32d, and an active layer 32a.
  • the TFT 32 is an inverted stagger type in which the gate electrode 32g is disposed below the source electrode 32s and the drain electrode 32d.
  • the gate electrode 32g is formed on the insulating substrate 30.
  • a charge storage electrode 34 is formed in order to increase the charge storage capacity of each pixel 31. A ground voltage is applied to the charge storage electrode 34.
  • An insulating film 35 made of silicon nitride (SiN x ) or the like is formed on the insulating substrate 30 so as to cover the gate electrode 32g and the charge storage electrode 34.
  • An active layer 32a is disposed on the insulating film 35 so as to face the gate electrode 32g.
  • the source electrode 32s and the drain electrode 32d are arranged on the active layer 32a with a predetermined interval. A portion of the drain electrode 32 d extends on the insulating film 35, and faces the charge storage electrode 34 via the insulating film 35 to constitute a capacitor 34 a.
  • the gate electrode 32g, the source electrode 32s, the drain electrode 32d, and the charge storage electrode 34 are made of aluminum (Al) or copper (Cu).
  • the active layer 32a is made of amorphous silicon.
  • a TFT protective film 36 made of silicon nitride (SiN x ) or the like is formed on the insulating film 35 so as to cover the source electrode 32s, the drain electrode 32d, and the active layer 32a.
  • a first planarizing film 37 having a flat surface is formed so as to eliminate the uneven structure due to the TFT 32.
  • the first planarization film 37 is formed by applying an organic material.
  • a contact hole 38 is formed in the first planarizing film 37 and the TFT protective film 36 at a position facing the drain electrode 32d.
  • the PD 33 is connected to the drain electrode 32 d of the TFT 32 through the contact hole 38.
  • the PD 33 is formed by a lower electrode 33a, a semiconductor layer 33b, and an upper electrode 33c.
  • the lower electrode 33a is formed on the first planarization film 37 so as to cover the inside of the contact hole 38 and the TFT 32, and is connected to the drain electrode 32d.
  • the lower electrode 33a is made of aluminum (Al) or indium tin oxide (ITO).
  • the semiconductor layer 33b is stacked on the lower electrode 33a.
  • the semiconductor layer 33b is PIN-type amorphous silicon, in which an n + layer, an i layer, and a p + layer are stacked in order from the bottom.
  • the upper electrode 33c is formed on the semiconductor layer 33b.
  • the upper electrode 33c is formed of a highly light-transmitting material such as indium tin oxide (ITO) or indium zinc oxide (IZO).
  • a second flattening film 39 having a flat surface is formed so as to eliminate the uneven structure due to the PD33. Similar to the first planarization film 37, the second planarization film 39 is formed by applying an organic material.
  • a contact hole 40 is formed in the second planarization film 39 so as to expose the upper electrode 33c.
  • the common electrode wiring 41 is connected to the upper electrode 33 c through the contact hole 40.
  • the common electrode wiring 41 is commonly connected to the upper electrode 33c of each PD 33, and is used to apply a bias voltage to the upper electrode 33c.
  • the upper electrode 33c is made of aluminum (Al) or copper (Cu).
  • a protective insulating film 42 is formed on the second planarization film 39 and the common electrode wiring 41.
  • the protective insulating film 42 is formed of silicon nitride (SiN x ) or the like, like the TFT protective film 36.
  • the external terminal 21 b includes a terminal electrode 43 formed on the insulating substrate 30 and a metal film 45 provided so as to cover the contact hole 44 formed in the insulating film 35 and the TFT protective film 36. .
  • the scintillator 20 is formed on the flat surface of the second flattening film 39 via a protective insulating film 42.
  • the non-columnar crystal layer 20b is formed on the protective insulating film 42 by vacuum deposition.
  • the non-columnar crystal layer 20b is composed of a plurality of particulate crystals and has a small adhesion between the crystals (a high space filling rate), and thus has high adhesion with the protective insulating film.
  • the columnar crystal 20a is a crystal grown by vacuum deposition on the basis of the non-columnar crystal layer 20b.
  • the thickness of the non-columnar crystal layer 20b is preferably 5 ⁇ m or more.
  • the diameter of the columnar crystal 20a is substantially uniform along the longitudinal direction, and is about 6 ⁇ m.
  • the sealing film 23 is formed around the scintillator 20.
  • the sealing film 23 covers the scintillator 20 and the second planarization film 39.
  • the light reflecting film 24 is formed as described above.
  • the pixels 31 are arranged in a two-dimensional matrix on the insulating substrate 30.
  • Each pixel 31 includes the TFT 32, the PD 33, and the capacitor 34a as described above.
  • Each pixel 31 is connected to the gate wiring 50 and the data wiring 51.
  • the gate lines 50 extend in the row direction and are arranged in a plurality in the column direction.
  • a plurality of data lines 51 are arranged in the row direction so as to extend in the column direction and cross the gate lines 50.
  • the gate wiring 50 is connected to the gate electrode 32 g of the TFT 32.
  • the data line 51 is connected to the drain electrode 32 d of the TFT 32.
  • One end of the gate wiring 50 is connected to the gate driver 26a.
  • One end of the data line 51 is connected to the charge amplifier 26b.
  • the gate driver 26a sequentially applies a gate drive signal to each gate line 50, and turns on the TFT 32 connected to each gate line 50. When the TFT 32 is turned on, the charges accumulated in the PD 33 and the capacitor 34a are output to the data wiring 51.
  • the charge amplifier 26b has a charge storage capacitor (not shown), integrates the charge output to the data wiring 51 and converts it into a voltage signal.
  • the signal processing unit 25a generates image data by performing A / D conversion, gain correction processing, and the like on the voltage signal output from the charge amplifier 26b.
  • the image memory 25b includes a flash memory and stores image data generated by the signal processing unit 25a. The image data stored in the image memory 25b can be read out to the outside via a wired or wireless communication unit (not shown).
  • a photographer places a subject 61 on the X-ray image detection device 10 and places the subject 61 on the subject 61.
  • the X-ray source 60 is disposed so as to face each other.
  • the X-ray XR is emitted from the X-ray source 60, and the X-ray XR transmitted through the subject 61 is irradiated onto the irradiation surface 14a of the X-ray image detection apparatus 10.
  • the X-ray XR irradiated to the irradiation surface 14a passes through the second adhesive layer 22b, the reinforcing substrate 22, the first adhesive layer 22a, and the photoelectric conversion panel 21 in this order, and enters the scintillator 20.
  • the scintillator 20 absorbs X-rays XR and generates visible light. Visible light is generated in the scintillator 20 mainly on the non-columnar crystal layer 20b side in the columnar crystal 20a. Visible light generated in the columnar crystal 20a propagates in each columnar crystal 20a by the light guide effect, passes through the non-columnar crystal layer 20b, and enters the photoelectric conversion panel 21. Further, the visible light propagating in the columnar crystal 20a in the direction of the tip portion 20c and reflected from the tip portion 20c is reflected by the light reflecting film 24, returns to the columnar crystal 20a, and passes through the non-columnar crystal layer 20b. Then, the light enters the photoelectric conversion panel 21.
  • Visible light incident on the photoelectric conversion panel 21 is converted into electric charge by the PD 33 for each pixel 31, and the electric charge is accumulated in the PD 33 and the capacitor 34a.
  • a gate drive signal is sequentially applied to the gate electrode 32g of the TFT 32 through the gate wiring 50 by the gate driver 26a.
  • the TFTs 32 arranged in the row direction are sequentially turned on in the column direction, and the charges accumulated in the PD 33 and the capacitor 34a are output to the data wiring 51 via the turned-on TFTs 32.
  • the charge output to the data wiring 51 is converted into a voltage signal by the charge amplifier 26b and input to the signal processing unit 25a.
  • Image data is generated by the signal processor 25a based on the voltage signals for all the pixels 31 and stored in the image memory 25b.
  • the X-ray image detection apparatus 10 may be slightly bent by a load from the subject 61 as shown by a two-dot chain line in FIG.
  • the housing 14 has a monocoque structure and is excellent in weight reduction, but has a low load resistance and is easily bent. Since the X-ray image detection apparatus 10 is an ISS type and the photoelectric conversion panel 21 is disposed on the irradiation surface 14 a side, the load from the subject 61 acts on the photoelectric conversion panel 21 via the housing 14.
  • the reinforcing substrate 22 since the reinforcing substrate 22 is attached to the surface of the photoelectric conversion panel 21 on the X-ray incident side, the deflection of the photoelectric conversion panel 21 due to the load from the subject 61 is reduced.
  • This reinforcing substrate 22 has a Young's modulus of 10 GPa or less, which is lower than the Young's modulus (about 70 GPa) of the insulating substrate 30, and functions as a reinforcing layer. Even if the photoelectric conversion panel 21 is bent, the stress generated in the photoelectric conversion panel 21 due to the load is relaxed by the reinforcing substrate 22 and hardly reaches the breaking stress of the insulating substrate 30. Further, the non-columnar crystal layer 20 b of the scintillator 20 is in close contact with the other surface of the photoelectric conversion panel 21, and this non-columnar crystal layer 20 b also relieves the stress of the photoelectric conversion panel 21.
  • the tensile stress generated by bending decreases as the thickness of the glass plate forming the insulating substrate 30 decreases.
  • the fracture stress of a glass plate is about 50 MPa.
  • the insulating substrate 30 since the insulating substrate 30 has a thickness of 0.5 mm or less, the insulating substrate 30 can be bent until the radius of curvature is about 350 mm. This allows the maximum stress assumed in the monocoque housing (see, for example, JP 2009-101053 A), and the insulating substrate 30 is not destroyed.
  • the reinforcing substrate 22 is formed of a resin such as polyimide or PET, but the thermal expansion coefficient of the resin is about one digit larger than that of the glass plate on which the insulating substrate 30 is formed.
  • the difference in coefficient of thermal expansion between the insulating substrate 30 and the reinforcing substrate 22 is large, there is a problem that warpage occurs due to a temperature change. For this reason, when forming the reinforcement board
  • the glass transition temperature Tg is about 200 to 300 ° C.
  • PET has a glass transition temperature Tg of about 80 ° C.
  • the reinforcing substrate 22 becomes difficult to deform due to a temperature change or the like, and the occurrence of warpage is suppressed.
  • the reinforcing substrate 22 is particularly effective for preventing warping that occurs when the insulating substrate 30 is thinned.
  • the glass transition temperature Tg is used as the resin forming the reinforcing substrate 22. It is preferable to use a high polyimide. On the other hand, PET having a low glass transition temperature Tg has an advantage of easy heat treatment.
  • a cut 22c may be formed in the vicinity of the center of each side of the rectangular flat reinforcing substrate 22.
  • the reinforcing substrate 22 is formed of resin, but may be formed of a material other than resin.
  • a material having low X-ray absorption is preferable, and examples thereof include glass, carbon, and aluminum.
  • the insulating substrate 30 is a glass plate, and thus the thermal expansion coefficients of the insulating substrate 30 and the reinforcing substrate 22 are equal, so that the occurrence of warpage due to a temperature change is suppressed.
  • the reinforcing substrate 22 is formed of glass, it is preferable to use soda glass that has less X-ray absorption than non-alkali glass and is inexpensive.
  • thermal expansion coefficient of carbon is approximately the same as the thermal expansion coefficient of glass (several ppm / K), generation of warpage due to temperature change is similarly suppressed when the reinforcing substrate 22 is formed of carbon.
  • aluminum has a coefficient of thermal expansion that is about an order of magnitude higher than that of glass or carbon, and has a higher X-ray absorption in a region where the X-ray energy is low (energy region in mammography imaging). Although it is inferior as a material, there is an advantage that it is inexpensive.
  • the insulating substrate 30 when the insulating substrate 30 is thinned, it becomes difficult to be destroyed even if it is bent as described above, but it is still broken by dropping or the like. Ease of use) is reduced. For this reason, handling property can be improved by forming the reinforcement board
  • a light reflection layer 70 may be provided between the reinforcement substrate 22 and 22a.
  • the light reflecting layer 70 is formed by depositing a metal having light reflectivity on the surface of the reinforcing substrate 22 or attaching a metal foil having light reflectivity. As this metal, aluminum with low X-ray absorption is preferable.
  • a part of the visible light emitted from the scintillator 20 is transmitted without being photoelectrically converted by the photoelectric conversion panel 21, but when the insulating substrate 30 of the photoelectric conversion panel 21 is thinned, the visible light is transmitted through the insulating substrate 30. Visible light is less likely to be scattered (scattering length is shortened). As described above, when the insulating substrate 30 is thinned, by providing the light reflection layer 70, visible light transmitted through the photoelectric conversion panel 21 is reflected and returned to the photoelectric conversion panel 21. Image blur due to scattering hardly occurs, and only the conversion efficiency of visible light can be improved.
  • the light reflecting layer 70 may be formed integrally with the reinforcing substrate 22 by dispersing light reflecting fine particles (granular alumina or titanium oxide) on the surface layer of the resin reinforcing substrate 22. Furthermore, as described above, if the reinforcing substrate 22 is formed of aluminum, the reinforcing substrate 22 can also have the function of the light reflecting layer 70.
  • the photoelectric conversion panel 21 is exposed to X-ray irradiation, and the insulating substrate 30 is charged with charges, and the charged charges may be localized, thereby causing unevenness in the image.
  • a conductive layer 71 may be provided between the first adhesive layer 22 a and the reinforcing substrate 22, and a ground voltage may be applied to the conductive layer 71.
  • the first adhesive layer 22a is also preferably conductive.
  • the conductive layer 71 is formed by vapor-depositing a conductive metal or pasting a conductive metal foil on the surface of the reinforcing substrate 22. If the conductive layer 71 is formed of a metal having conductivity and light reflectivity such as aluminum, the function of the light reflection layer 70 described above can be provided. Also in this case, similarly to the light reflecting layer 70, the conductive layer 71 can be formed integrally with the reinforcing substrate 22 by dispersing conductive fine particles (granular alumina etc.) on the surface layer of the resin-made reinforcing substrate 22. It is.
  • the X-ray image detection device 10 is an ISS type
  • heat from the subject 61 is transmitted to the photoelectric conversion panel 21 via the irradiation surface 14a of the housing 14 during imaging, and the photoelectric conversion panel.
  • unevenness occurs in the image due to the heat distribution in 21. This is because the dark current generated in each PD 33 has temperature dependence. Further, when the thickness of the insulating substrate 30 is thin, heat is easily transmitted to the PD 33.
  • thermal diffusion layer 72 between the first adhesive layer 22a and the reinforcing substrate 22 as shown in FIG.
  • the heat diffusion layer 72 is preferably sheet-like graphite or aluminum. If the heat diffusion layer 72 is formed of aluminum, the functions of the light reflection layer 70 and the conductive layer 71 described above can be provided. In this case as well, the thermal diffusion layer 72 can be formed integrally with the reinforcing substrate 22 by dispersing thermal diffusible fine particles (granular alumina or the like) in the surface layer of the resin reinforcing substrate 22.
  • the X-ray image detection apparatus 10 is the ISS type as described above, when the subject 61 receives an impact on the housing 14, the impact is easily transmitted to the photoelectric conversion panel 21. For this reason, it is also preferable to provide a buffer layer 73 between the first adhesive layer 22a and the reinforcing substrate 22 as shown in FIG.
  • the buffer layer 73 is formed by attaching an elastic body such as a sheet-like rubber or a viscoelastic body to the surface of the reinforcing substrate 22.
  • the reinforcing substrate 22 may be formed of an elastic body or a viscoelastic body so as to have a buffer property.
  • the reinforcing substrate 22 is attached to the X-ray incident side of the photoelectric conversion panel 21, but as shown in FIG. 12, the X-ray image detection of the second embodiment.
  • the reinforcing substrate 81 is attached to the opposite side of the photoelectric conversion panel 21 from the radiation incident side.
  • the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
  • the surface on the X-ray incident side of the photoelectric conversion panel 21 is attached to the irradiation surface 14a side of the housing 14 via the first adhesive layer 82 made of epoxy resin or the like.
  • a reinforcing substrate 81 is attached to the other surface of the photoelectric conversion panel 21 via a second adhesive layer 73.
  • the scintillator 20 is deposited on the surface 71 a of the reinforcing substrate 81.
  • the non-columnar crystal layer 20b is deposited on the surface 81a of the reinforcing substrate 81, and a plurality of columnar crystals 20a are grown from the non-columnar crystal layer 20b.
  • the visible light generated by the scintillator 20 passes through the reinforcing substrate 81 and the second adhesive layer 83 and enters the photoelectric conversion panel 21. Therefore, the reinforcing substrate 81 and the second adhesive layer 83 are It is preferable to have high translucency.
  • the material of the reinforcing substrate 81 transparent polyimide, polyallate resin, OPS (Oriented Polystyrene Sheet) film, transparent resin such as aramid, and glass such as soda glass can be used.
  • the reinforcing substrate 81 is used as a vapor deposition substrate of the scintillator 20, it is preferable that the substrate has heat resistance capable of withstanding the vapor deposition temperature.
  • the OPS film has a heat resistance of about 250 ° C., it is most preferable as a material for the reinforcing substrate 81.
  • a material for the second adhesive layer 83 a light-transmitting epoxy resin, an acrylic resin, or the like can be used.
  • the reinforcing substrate 81 functions as a reinforcing layer of the photoelectric conversion panel 21, and the load resistance of the photoelectric conversion panel 21 is improved.
  • the thermal expansion coefficient of the photoelectric conversion panel 21 is 3 ppm / K
  • the thermal expansion coefficient of the scintillator 20 is as large as 60 ppm / K. Therefore, the scintillator 20 is added to the photoelectric conversion panel 21 as in the first embodiment. In the case where is directly deposited, the scintillator 20 may be peeled off from the photoelectric conversion panel 21 due to a temperature change. This peeling is more likely to occur as the thickness of the scintillator 20 is increased.
  • the second adhesive layer 83 that bonds the reinforcing substrate 81 to the photoelectric conversion panel 21 can easily separate the photoelectric conversion panel 21 and the reinforcing substrate 81 on which the scintillator 20 is vapor-deposited during repair or the like. Moreover, it is also preferable that it is tacky. Further, the second adhesive layer 83 may not be provided, and the reinforcing substrate 81 may be pressed against the photoelectric conversion panel 21 and fixed to the housing 14 or the like.
  • the light reflecting film 24 is formed of an aluminum film or an aluminum deposited film, but a resinous light reflecting film may be used instead.
  • a resinous light reflecting film as described in JP-A-2008-209124, a material in which granular alumina or titanium oxide is dispersed in a binder resin can be used.
  • the sealing film 23 is directly formed on the scintillator 20, but the sealing film 23 may be formed after the tip 20c of the columnar crystal 20a is hardened with hot melt resin. Good.
  • the sealing film 23 formed of polyparaxylene is used, but a sealing film of PET or aluminum may be used. In this case, it is preferable to form the sealing film so as to cover the scintillator 20 and the end of the sealing film is located inside the tapered end of the second planarization film 39.
  • the sealing film can be formed by a vapor deposition method using a mask or a hot melt method.
  • the X-ray image detection apparatuses 10 and 70 of the first and second embodiments can be applied to mammography imaging in which imaging is performed using the breast as the subject 61.
  • mammography in order to capture lesions in soft tissues such as skin, fat, and mammary glands, X-ray XR emitted from the X-ray source 60 has energy lower than 50 KeV (generally, about 28 KeV). X-rays are used.
  • soda glass having higher X-ray transparency than non-alkali glass is used for the insulating substrate 30 of the photoelectric conversion panel 21.
  • the main reason why the alkali-free glass has a low X-ray permeability is that the alkali-free glass contains barium.
  • barium has a K absorption edge of about 37 KeV, when the X-ray energy is lower than 37 KeV, there is no significant difference in X-ray transmission between alkali-free glass and soda glass.
  • the X-ray energy exceeds 37 KeV the X-ray transparency of soda glass is significantly improved as compared to alkali-free glass.
  • the X-ray energy is preferably 37 KeV or more in order to improve the X-ray absorption in the scintillator 20.
  • raising the X-ray energy from the X-ray energy (about 28 KeV) generally used in mammography imaging has the advantage of increasing the X-ray transmission and reducing the patient exposure.
  • Increasing the X-ray energy tends to reduce the contrast of the image, but this can be compensated by image processing. Therefore, the X-ray energy is preferably in the range of 37 KeV to 50 KeV.
  • the active layer 32a of the TFT 32 may be formed of an amorphous oxide semiconductor (for example, In—O system), an organic semiconductor material, a carbon nanotube, or the like.
  • amorphous oxide semiconductor for example, In—O system
  • IGZO In—Ga—ZnO 4
  • the insulating substrate 30 is thinned to 0.5 mm or less and has high flexibility, it is preferable to use an amorphous oxide semiconductor that is an oxide like the insulating substrate 30. This is because an oxide has a property of increasing flexibility when it is thinned.
  • the semiconductor layer 33b of the PD 33 may be an organic photoelectric conversion layer.
  • the organic photoelectric conversion layer includes a p-type organic semiconductor material and an n-type organic semiconductor material.
  • Exciton dissociation efficiency can be increased by joining a p-type organic semiconductor material and an n-type organic semiconductor material to form a donor-acceptor interface.
  • the organic photoelectric conversion layer of the structure which joined the p-type organic-semiconductor material and the n-type organic-semiconductor material expresses high photoelectric conversion efficiency.
  • an organic photoelectric conversion layer in which a p-type organic semiconductor material and an n-type organic semiconductor material are mixed is preferable because the junction interface is increased and the photoelectric conversion efficiency is improved.
  • the p-type organic semiconductor material is a donor organic semiconductor material (compound), which is mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound.
  • the metal complex etc. which it has as can be used.
  • any organic compound having an ionization potential smaller than that of the organic compound used as the n-type (acceptor property) compound may be used as the donor organic semiconductor.
  • the n-type organic semiconductor material is an acceptor organic semiconductor material, and is mainly represented by an electron-transporting organic compound and means an organic compound having a property of easily accepting electrons. More specifically, an n-type organic semiconductor refers to an organic compound having a higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound.
  • condensed aromatic carbocyclic compounds naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives
  • 5- to 7-membered heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms E.g., pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole , Benzoxazole, benzothiazole, carbazole, purine, triazolopy
  • Any organic dye may be used as the p-type organic semiconductor material or the n-type organic semiconductor material, but preferably a cyanine dye, a styryl dye, a hemicyanine dye, and a merocyanine dye (including zero methine merocyanine (simple merocyanine)).
  • fullerene represents fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C80, fullerene C82, fullerene C84, fullerene C90, fullerene C96, fullerene C240, fullerene C540, mixed fullerene, and fullerene nanotubes. It represents a compound to which a substituent is added.
  • the substituent for the fullerene derivative is preferably an alkyl group, an aryl group, or a heterocyclic group.
  • the alkyl group is more preferably an alkyl group having 1 to 12 carbon atoms, and the aryl group and the heterocyclic group are preferably a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring.
  • substituents may further have a substituent, and the substituents may be bonded as much as possible to form a ring.
  • substituents may be bonded as much as possible to form a ring.
  • you may have a some substituent and they may be the same or different.
  • a plurality of substituents may be combined as much as possible to form a ring.
  • the organic photoelectric conversion layer contains fullerene or a fullerene derivative
  • electrons generated by photoelectric conversion can be quickly transported to the upper electrode 33c or the lower electrode 33a via the fullerene molecule or the fullerene derivative molecule.
  • fullerene molecules or fullerene derivative molecules are connected to form an electron path, the electron transport property is improved, and high-speed response of the photoelectric conversion element can be realized.
  • it is preferable that fullerene or a fullerene derivative is contained in the organic photoelectric conversion layer in an amount of 40% (volume ratio) or more.
  • the p-type organic semiconductor is reduced, the junction interface becomes smaller, and the exciton dissociation efficiency decreases.
  • the fullerene or fullerene derivative contained in the organic photoelectric conversion layer preferably has a composition of 85% (volume ratio) or less.
  • the film formation temperature can be kept low from room temperature to about 250 ° C., and the active layer 32a and the semiconductor layer 33b are less than alkali. Therefore, soda glass containing an alkali element can be used as the insulating substrate 30.
  • amorphous silicon has a broad absorption spectrum, but organic photoelectric conversion materials have a sharp absorption spectrum in the visible range. Therefore, the visible light emitted from the scintillator 20 can be obtained by using the semiconductor layer 33b as an organic photoelectric conversion layer. It hardly absorbs electromagnetic waves other than light, and noise is suppressed.
  • X-rays are used as radiation.
  • radiation other than X-rays such as ⁇ -rays and ⁇ -rays may be used.
  • the present invention has been described by taking an electronic cassette as a portable radiographic image detection device as an example.
  • the present invention is a standing radiograph type radiological image detection device or the like. It is also applicable to.

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018173893A1 (fr) * 2017-03-22 2018-09-27 富士フイルム株式会社 Détecteur de rayonnement et dispositif d'imagerie radiographique
US10446771B2 (en) 2017-11-13 2019-10-15 Kabushiki Kaisha Toshiba Radiation detector
EP3770643A4 (fr) * 2018-03-19 2021-04-28 FUJIFILM Corporation Détecteur de rayonnement et dispositif de capture d'image radiographique

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102432252B1 (ko) 2017-06-13 2022-08-16 삼성전자주식회사 엑스선 검출기, 이를 포함한 엑스선 촬영 장치 및 그 제조 방법
WO2019181640A1 (fr) * 2018-03-19 2019-09-26 富士フイルム株式会社 Détecteur de rayonnement, dispositif de photographie radiographique et procédé de production de détecteur de rayonnement
JP7208941B2 (ja) 2020-02-20 2023-01-19 富士フイルム株式会社 放射線検出器、放射線画像撮影装置、及び放射線検出器の製造方法
WO2021177118A1 (fr) 2020-03-05 2021-09-10 富士フイルム株式会社 Détecteur de rayonnement, dispositif d'imagerie radiographique et procédé de fabrication de détecteur de rayonnement
JP7332784B2 (ja) 2020-03-05 2023-08-23 富士フイルム株式会社 放射線検出器、及び放射線画像撮影装置
JP7370950B2 (ja) 2020-09-28 2023-10-30 富士フイルム株式会社 放射線画像撮影装置
JP2022125517A (ja) * 2021-02-17 2022-08-29 キヤノン株式会社 放射線撮像装置及び放射線撮像システム

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012137438A (ja) * 2010-12-27 2012-07-19 Fujifilm Corp 放射線画像検出装置及びその製造方法
JP2012173275A (ja) * 2011-02-24 2012-09-10 Fujifilm Corp 放射線画像検出装置及び放射線撮影用カセッテ

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012137438A (ja) * 2010-12-27 2012-07-19 Fujifilm Corp 放射線画像検出装置及びその製造方法
JP2012173275A (ja) * 2011-02-24 2012-09-10 Fujifilm Corp 放射線画像検出装置及び放射線撮影用カセッテ

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018173893A1 (fr) * 2017-03-22 2018-09-27 富士フイルム株式会社 Détecteur de rayonnement et dispositif d'imagerie radiographique
JPWO2018173893A1 (ja) * 2017-03-22 2019-03-28 富士フイルム株式会社 放射線検出器及び放射線画像撮影装置
US10838082B2 (en) 2017-03-22 2020-11-17 Fujifilm Corporation Radiation detector and radiographic imaging apparatus
US10446771B2 (en) 2017-11-13 2019-10-15 Kabushiki Kaisha Toshiba Radiation detector
EP3770643A4 (fr) * 2018-03-19 2021-04-28 FUJIFILM Corporation Détecteur de rayonnement et dispositif de capture d'image radiographique
US11262461B2 (en) 2018-03-19 2022-03-01 Fujifilm Corporation Radiation detector and radiographic imaging device

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