WO2010010728A1 - Radiation image conversion panel and radiographic apparatus using the same - Google Patents

Radiation image conversion panel and radiographic apparatus using the same Download PDF

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Publication number
WO2010010728A1
WO2010010728A1 PCT/JP2009/054412 JP2009054412W WO2010010728A1 WO 2010010728 A1 WO2010010728 A1 WO 2010010728A1 JP 2009054412 W JP2009054412 W JP 2009054412W WO 2010010728 A1 WO2010010728 A1 WO 2010010728A1
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WIPO (PCT)
Prior art keywords
scintillator
layer
panel
image conversion
radiation image
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PCT/JP2009/054412
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French (fr)
Japanese (ja)
Inventor
貴文 柳多
直 有本
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コニカミノルタエムジー株式会社
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Publication of WO2010010728A1 publication Critical patent/WO2010010728A1/en

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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

Definitions

  • the present invention relates to a radiation image conversion panel provided with a scintillator panel and a planar light receiving element, and a technique for improving image characteristics (sharpness and image unevenness) of an X-ray imaging system using the same.
  • radiographic images such as X-ray images have been widely used for medical diagnosis in medical settings.
  • radiographic images using intensifying screens and film systems have been developed as an imaging system that combines high reliability and excellent cost performance as a result of high sensitivity and high image quality in the long history.
  • the image information is so-called analog image information, and free image processing and instantaneous electric transmission cannot be performed like the digital image information that has been developed in recent years.
  • a scintillator plate made of a phosphor having the property of emitting light by radiation is used.
  • the luminous efficiency is high. It will be necessary to use scintillator plates.
  • the light emission efficiency of the scintillator plate is determined by the thickness of the phosphor layer and the X-ray absorption coefficient of the phosphor. The thicker the phosphor layer, the more scattered the emitted light in the phosphor layer. Occurs and sharpness decreases. Therefore, when the sharpness necessary for the image quality is determined, the film thickness is determined.
  • CsI cesium iodide
  • the scintillator (phosphor layer) based on CsI has a deliquescent property and has a drawback that the characteristics deteriorate with time.
  • a moisture-proof protective layer on the surface of a scintillator (phosphor layer) based on CsI.
  • a method of covering the upper and side surfaces of the scintillator layer (also referred to as “phosphor layer”) and the outer periphery of the scintillator layer of the substrate with polyparaxylylene resin see, for example, Patent Document 1).
  • Patent Document 1 the polyparaxylylene resin described in Patent Document 1 is weak in moisture resistance, cannot sufficiently protect the phosphor layer, and the polyparaxylylene resin enters the gaps between the columnar crystals constituting the scintillator layer. The light guide effect was hindered.
  • a transparent resin film having a moisture permeability of less than 1.2 g / m 2 ⁇ day covers at least the side opposite to the side of the scintillator layer facing the support and the side surface (for example, Patent Document 2). See).
  • Patent Document 2 when a transparent organic polymer film such as polypropylene or polyethylene terephthalate is installed as a protective layer in close contact with the phosphor layer, high moisture resistance is obtained, but sharp In order to avoid this, it is necessary to reduce the thickness of the film to 5 ⁇ m or less, and it is not possible to protect the phosphor layer from chemical alteration or physical impact. The actual situation was that it was sufficient and could not be practically used as a protective layer. Further, for example, there are methods disclosed in Japanese Patent Application Laid-Open Nos. 5-329661 and 6-331749 for arranging the scintillator panel on the surface of the planar light receiving element. Deterioration of sharpness on the element surface is inevitable.
  • Japanese Patent Application Laid-Open Nos. 5-329661 and 6-331749 for arranging the scintillator panel on the surface of the planar light receiving element. Deterioration of sharpness on the element surface is inevitable.
  • Japanese Patent Application Laid-Open No. 2002-116258 shows an example in which a flexible protective layer such as polyparaxylylene is used as the protective layer.
  • a flexible protective layer such as polyparaxylylene
  • the protective layer and the planar light receiving layer are used. Since the element surfaces are in close contact with each other, the light emitted from the scintillator propagates in the protective layer for the reason described later, and the sharpness deteriorates.
  • a phosphor layer is generally formed on a rigid substrate such as aluminum or amorphous carbon, and the entire surface of the scintillator is covered with a protective film. Yes (see, for example, Patent Document 3).
  • a scintillator as a substitute for the scintillator, such as a method of forming a scintillator directly by vapor deposition on the image sensor or a low-sharp but flexible medical intensifying screen. It has been broken.
  • the above disclosed method has a problem that air is easily trapped between the scintillator and the photoelectric conversion element section, and that the gap is likely to be large, so that MTF is lowered and image unevenness is likely to occur.
  • the present invention has been made in view of the above-described problems and situations, and its solution is to improve the adhesion between the scintillator panel and the planar light-receiving element surface to prevent sharpness (MTF) degradation and image unevenness. And providing a radiation image conversion panel. Moreover, it is providing the X-ray imaging system using this.
  • the inventors have found that the problem can be solved by controlling the surface average roughness of the scintillator panel and the planar light receiving element surface within a specific range. Invented. That is, the said subject which concerns on this invention is solved by the following means.
  • a radiation image conversion panel including a scintillator panel and a planar light receiving element, wherein the surface average roughness (Ra) on the side of the scintillator panel facing the planar light receiving element is 0.01 to 3.0 ⁇ m, and the planar light receiving element A radiation image conversion panel having an average surface roughness (Ra) on the side facing the scintillator panel of 0.001 to 0.5 ⁇ m.
  • An X-ray imaging system wherein the radiation image conversion panel according to any one of 1 to 8 is disposed in a portable container, X-rays are irradiated, and a radiation image is read.
  • FIG. 2 Schematic plan view of scintillator panel Schematic cross-sectional view along AA 'in FIG. Schematic diagram showing the state of light refraction in the gap shown in FIG. 2 and the state of light refraction in a state where the conventional protective film and the scintillator layer (phosphor layer) are in close contact with each other.
  • the radiation image conversion panel of the present invention is a radiation image conversion panel including a scintillator panel and a planar light receiving element, and has a surface average roughness (Ra) on the side facing the planar light receiving element of the scintillator panel of 0.01 to
  • the surface average roughness (Ra) of the flat light-receiving element facing the scintillator panel is 0.001 to 0.5 ⁇ m.
  • the surface average roughness (Ra) of the scintillator panel is preferably 0.01 to 1.0 ⁇ m, and more preferably 0.1 to 0.5 ⁇ m.
  • the surface average roughness (Ra) of the planar light receiving element is preferably 0.001 to 0.1 ⁇ m, and more preferably 0.001 to 0.05 ⁇ m.
  • it is preferable that the surface average roughness (Ra) of the scintillator panel is larger than the surface average roughness (Ra) of the planar light receiving element from the viewpoint of improving the adhesion between the scintillator panel and the planar light receiving element surface.
  • the scintillator panel is in close contact with the planar light receiving element by being pressed by an elastic member. Further, it is also preferable that the scintillator panel is in close contact with the planar light receiving element and the periphery thereof is sealed with a tight seal member by reducing the gas in the gap between the scintillator panel and the planar light receiving element.
  • the scintillator panel has flexibility.
  • attachment sealing member is ultraviolet curable resin.
  • the scintillator panel has a scintillator layer and the scintillator layer is in direct contact with the planar light receiving element.
  • the scintillator layer preferably contains cesium iodide (CsI) as a main component.
  • the scintillator layer is preferably a phosphor columnar crystal formed by a vapor deposition method.
  • the radiographic image conversion panel of the present invention can be suitably used in an X-ray imaging system in which an X-ray is exposed by X-rays being placed in a portable container.
  • the radiation image conversion panel of the present invention is preferably a radiation image conversion panel having a scintillator panel and a planar light receiving element.
  • the scintillator panel is a scintillator panel (also referred to as “scintillator plate”) having a scintillator layer on the substrate, and is also referred to as a reflective layer and a reflective layer protective film (“undercoat layer”) on the substrate. ) And a scintillator layer are preferably provided in this order.
  • the surface average roughness (Ra) on the scintillator layer is 0.01 to 3.0 ⁇ m whether or not a protective layer is provided on the scintillator layer. Cost. Therefore, in the phosphor columnar crystal forming step by the vapor deposition (vapor deposition) method, it is necessary to make adjustments so as to satisfy the requirements by controlling the vapor deposition density, the vapor deposition temperature, and the like.
  • the “surface average roughness” as used in the present invention is the centerline average surface roughness (Ra) and conforms to JIS B 0601: 2001.
  • Examples of the measuring device that can be used include Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd. In the practice of the present invention, the cutoff value was evaluated at 0.8 mm.
  • the scintillator panel according to the present invention preferably has flexibility.
  • “having flexibility” means that the elastic modulus (E120) at 120 ° C. is 1000 to 6000 N / mm 2 .
  • the “elastic modulus” refers to the slope of the stress with respect to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS C 2318 and the corresponding stress have a linear relationship using a tensile tester. Is what we asked for. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.
  • Scintillator layer As a material for forming the phosphor constituting the scintillator layer (also referred to as “phosphor layer”) according to the present invention, various known phosphor materials can be used, but changes from X-ray to visible light can be used. Since the rate is relatively high and the phosphor can be easily formed into a columnar crystal structure by vapor deposition, scattering of the emitted light within the crystal can be suppressed by the light guide effect, and the thickness of the scintillator layer can be increased. Therefore, cesium iodide (CsI) is preferable.
  • CsI cesium iodide
  • CsI alone has low luminous efficiency
  • various activators are added.
  • a mixture of CsI and sodium iodide (NaI) in an arbitrary molar ratio can be mentioned.
  • CsI as disclosed in Japanese Patent Application Laid-Open No. 2001-59899 is deposited, and thallium (Tl), europium (Eu), indium (In), lithium (Li), potassium (K), rubidium (Rb) ), CsI containing an activating substance such as sodium (Na) is preferred.
  • thallium (Tl) and europium (Eu) are particularly preferable.
  • thallium (Tl) is preferred.
  • thallium activated cesium iodide (CsI: Tl) is preferable because it has a wide emission wavelength from 400 nm to 750 nm.
  • thallium compound as an additive containing one or more types of thallium compounds according to the present invention, various thallium compounds (compounds having oxidation numbers of + I and + III) can be used.
  • a preferred thallium compound is thallium bromide (TlBr), thallium chloride (TlCl), thallium fluoride (TlF, TlF 3 ), or the like.
  • the melting point of the thallium compound according to the present invention is preferably in the range of 400 to 700 ° C. If the temperature exceeds 700 ° C., the additives in the columnar crystals exist non-uniformly, resulting in a decrease in luminous efficiency.
  • the melting point is a melting point at normal temperature and pressure.
  • the molecular weight of the thallium compound is preferably in the range of 206 to 300.
  • the content of the additive is desirably an optimum amount according to the target performance and the like, but is 0.001 to 50 mol%, and further preferably 0.000 to the content of cesium iodide. It is preferably 1 to 10.0 mol%.
  • the additive when the additive is 0.001 mol% or more with respect to cesium iodide, the emission luminance obtained by using cesium iodide alone is improved, which is preferable in terms of obtaining the target emission luminance. Moreover, it is preferable that it is 50 mol% or less because the properties and functions of cesium iodide can be maintained.
  • the temperature range of ⁇ 50 ° C. to + 20 ° C. is based on the glass transition temperature of the polymer film. It requires heat treatment for 1 hour or more in an atmosphere. Thereby, the deformation
  • the scintillator layer according to the present invention is preferably a columnar phosphor layer containing cesium iodide, and is preferably formed by a vapor phase growth method.
  • a vapor phase growth method a conventionally known vacuum deposition method, sputtering method, CVD method or the like can be used.
  • the thickness of the scintillator layer is preferably 100 to 800 ⁇ m, and more preferably 120 to 700 ⁇ m from the viewpoint of obtaining a good balance between luminance and sharpness characteristics.
  • the protective layer according to the present invention focuses on protecting the scintillator layer. That is, cesium iodide (CsI) absorbs water vapor in the air and deliquesces when exposed to a high hygroscopic property, and therefore the main purpose is to prevent this.
  • the protective layer can be formed using various materials.
  • a protective film can be provided on the scintillator layer of the scintillator plate.
  • the scintillator panel is sealed by a first protective film disposed on the scintillator layer side and a second protective film disposed on the outside of the substrate, and the first protective film is physicochemically bonded to the scintillator layer. It is preferable to set it as the aspect which is not adhere
  • non-bonded state is a state in which the scintillator layer surface and the protective film can be treated as a discontinuous optically and mechanically even though the scintillator layer surface and the protective film are point contacted microscopically. It can be said.
  • the average surface roughness (Ra) of the protective layer is 0.01 to 3.0 ⁇ m. Therefore, it is necessary to select a protective film that satisfies this requirement or to adopt formation conditions.
  • the average surface roughness (Ra) of the protective layer is preferably 0.01 to 1.0 ⁇ m, and more preferably 0.1 to 0.5 ⁇ m.
  • Examples of the configuration of the protective film used in the present invention include a multilayer laminated material having a configuration of a protective layer (outermost layer) / intermediate layer (moisture-proof layer) / innermost layer (thermal welding layer). Furthermore, each layer can be a multilayer as required.
  • thermoplastic resin film As the innermost thermoplastic resin film, it is preferable to use EVA, PP, LDPE, LLDPE and LDPE, LLDPE produced by using a metallocene catalyst, or a film using a mixture of these films and HDPE films.
  • Intermediate layer moisture-proof layer
  • the intermediate layer include layers having at least one inorganic film as described in JP-A-6-95302 and the vacuum handbook revised editions p132 to p134 (ULVAC Japan Vacuum Technology KK). It is done.
  • the inorganic film include a metal vapor-deposited film and an inorganic oxide vapor-deposited film.
  • metal vapor deposition film examples include ZrN, SiC, TiC, Si 3 N 4 , single crystal Si, ZrN, PSG, amorphous Si, W, aluminum, and the like, and a particularly preferable metal vapor deposition film includes, for example, aluminum. .
  • thermoplastic resin film used as the base material of the intermediate layer is ethylene tetrafluoroethyl copolymer (ETFE), high-density polyethylene (HDPE), expanded polypropylene (OPP), polystyrene (PS), polymethyl Film materials used for general packaging films such as methacrylate (PMMA), biaxially stretched nylon 6, polyethylene terephthalate (PET), polycarbonate (PC), polyimide, polyether styrene (PES) can be used.
  • ETFE ethylene tetrafluoroethyl copolymer
  • HDPE high-density polyethylene
  • OPP expanded polypropylene
  • PS polystyrene
  • PMMA methacrylate
  • PET polyethylene terephthalate
  • PC polycarbonate
  • PES polyimide
  • PES polyether styrene
  • a method for forming a deposited film vacuum technology handbook and packaging technology Vol 29-No. 8, for example, by resistance or high frequency induction heating method, electrobeam (EB) method, plasma (PCVD) or the like.
  • the thickness of the deposited film is preferably in the range of 40 to 200 nm, more preferably in the range of 50 to 180 nm.
  • Low density which is a polymer film used as a general packaging material (for example, a polymer film described in Toray Research Center Co., Ltd., a new development of functional packaging materials) as a thermoplastic resin film used via a vapor-deposited film sheet
  • Polyethylene LDPE
  • HDPE linear low density polyethylene
  • LLDPE linear low density polyethylene
  • CPP unstretched polypropylene
  • OPP stretched nylon (ONy), PET, cellophane, polyvinyl alcohol (PVA), stretched vinylon (OV)
  • An ethylene-vinyl acetate copolymer (EVOH), vinylidene chloride (PVDC), a fluorine-containing olefin (fluoroolefin) polymer, a fluorine-containing olefin copolymer, or the like can be used.
  • thermoplastic resin film a multilayer film made by coextrusion with a different film, a multilayer film made by laminating at different stretching angles, etc. can be used as needed. Furthermore, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties of the packaging material.
  • LDPE low density polyethylene
  • LLDPE low density polyethylene
  • metallocene catalyst a metallocene catalyst
  • a film using a mixture of these films and HDPE films are used as the innermost thermoplastic resin film.
  • the thermoplastic resin film used for the protective layer may be a simple substance or may be used by laminating two or more kinds of films as required.
  • Saran UB is a vinylidene chloride / acrylic acid ester copolymer resin manufactured by Asahi Kasei Corporation
  • Bi-axially stretched film made from a material such as K-OP / PP, K-PET / LLDPE, K-Ny / EVA (where K is a film coated with vinylidene chloride resin) or the like is used. .
  • a method for producing these protective films various generally known methods are used. For example, a wet laminate method, a dry laminate method, a hot melt laminate method, an extrusion laminate method, and a thermal laminate method are used. Is possible. Of course, the same method can be used in the case where a film on which an inorganic material is deposited is not used, but in addition to these, depending on the material used, it can be formed by a multilayer inflation method or a coextrusion method.
  • thermoplastic resins such as various polyethylene resins, various polypropylene resins, hot melt adhesives, ethylene-propylene copolymer resins, ethylene-vinyl acetate copolymer resins, ethylene copolymer such as ethylene-ethyl acrylate copolymer resins, etc.
  • thermoplastic resin hot-melt adhesives such as coalescence resins, ethylene-acrylic acid copolymer resins, ionomer resins, and other hot-melt rubber adhesives.
  • emulsion-type adhesives that are emulsion and latex adhesives are polyvinyl acetate resin, vinyl acetate-ethylene copolymer resin, vinyl acetate and acrylate copolymer resin, vinyl acetate and maleate ester.
  • copolymer resins acrylic acid copolymers, ethylene-acrylic acid copolymers, and the like.
  • latex adhesives include rubber latexes such as natural rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), and chloroprene rubber (CR).
  • adhesives for dry laminating include isocyanate adhesives, urethane adhesives, polyester adhesives, and others, paraffin wax, microcrystalline wax, ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer.
  • Known adhesives such as hot melt laminate adhesives, pressure sensitive adhesives, heat sensitive adhesives and the like blended with polymer resins can also be used.
  • the polyolefin resin adhesive for extrusion laminating includes, in addition to various polymers such as polyethylene resins, polypropylene resins, polybutylene resins, and ethylene copolymer (EVA, EEA, etc.) resins, Ionomer resin (ionic copolymer resin) such as L-LDPE resin copolymerized with ethylene and other monomers ( ⁇ -olefin), Surin from Dupot, Himiran from Mitsui Polychemical, and Mitsui Petrochemical Admer (adhesive polymer), etc.
  • Ionomer resin ionic copolymer resin
  • L-LDPE resin copolymerized with ethylene and other monomers ⁇ -olefin
  • Surin from Dupot
  • Himiran from Mitsui Polychemical
  • Mitsui Petrochemical Admer adhesive polymer
  • Other UV curable adhesives have recently begun to be used.
  • LDPE resin and L-LDPE resin are preferred because they are inexpensive
  • a mixed resin in which two or more of the above-described resins are blended to cover the defects of each resin is particularly preferable.
  • L-LDPE resin and LDPE resin are blended, spreadability is improved and neck-in is reduced, so that the lamination speed is improved and pinholes are reduced.
  • the thickness of the protective film is preferably 12 to 60 ⁇ m, more preferably 20 to 40 ⁇ m, taking into consideration the formation of voids, the scintillator layer (phosphor layer) protection, sharpness, moisture resistance, workability, and the like. preferable.
  • the haze ratio is preferably 3% or more and 40% or less, more preferably 3 to 10% in consideration of sharpness, radiation image unevenness, manufacturing stability, workability, and the like.
  • a haze rate shows the value measured by Nippon Denshoku Industries Co., Ltd. NDH 5000W. The required haze ratio is appropriately selected from commercially available polymer films and can be easily obtained.
  • the light transmittance of the protective film is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, scintillator emission wavelength, etc., but a film having a light transmittance of 99% or more is difficult to obtain industrially. Substantially 99% to 70% is preferable.
  • the moisture permeability of the protective film is preferably 50 g / m 2 ⁇ day (40 ° C., 90% RH) (measured according to JIS Z0208) or less, more preferably 10 g / m in consideration of the scintillator layer protection, deliquescence and the like. 2 ⁇ day (40 ° C./90% RH) (measured according to JIS Z0208) or less is preferable, but a film having a water vapor transmission rate of 0.01 g / m 2 ⁇ day (40 ° C./90% RH) or less is industrially used.
  • the following is preferable, and more preferably 0.1 g / m 2 ⁇ day (40 ° C. ⁇ 90% RH) or more and 10 g / m 2 ⁇ day (40 ° C. ⁇ 90% RH) (measured according to JIS Z0208) or less.
  • an organic thin film for example, a polyparaxylylene film, is formed on the entire surface of the scintillator and the substrate by a CVD method (Chemical Vapor Deposition; also referred to as “chemical vapor deposition method”). It can be a protective layer.
  • CVD method Chemical Vapor Deposition; also referred to as “chemical vapor deposition method”. It can be a protective layer.
  • the reflective layer according to the present invention is for reflecting light emitted from a phosphor (scintillator) to enhance light extraction efficiency.
  • the reflective layer is preferably formed of a material containing any element selected from the element group consisting of Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au.
  • a metal thin film made of the above elements for example, an Ag film, an Al film, or the like. Two or more such metal thin films may be formed.
  • the lower layer is a layer containing Cr from the viewpoint of improving the adhesion to the substrate.
  • a layer made of a metal oxide such as SiO 2 or TiO 2 may be provided in this order on the metal thin film to further improve the reflectance.
  • the thickness of the reflective layer is preferably 0.01 to 0.3 ⁇ m from the viewpoint of the emission light extraction efficiency.
  • a substrate made of anodized aluminum or the like can be used as the substrate.
  • the effect of increasing the light output without providing a special reflective layer can be obtained by setting the regular reflectance of visible light at an incident angle of 45 ° of the anodized film to 60% or more.
  • the reflective layer protective film (also referred to as “undercoat layer”) according to the present invention is preferably provided between the reflective layer and the scintillator layer from the viewpoint of protecting the reflective layer.
  • the reflective layer protective film preferably contains a polymer binder (binder), a dispersant and the like.
  • the thickness of the reflective layer protective film is preferably 0.1 to 3 ⁇ m. In addition, if it is 3 micrometers or less, the light scattering in a reflection layer protective film will be small, and sharpness will be favorable. Further, when the thickness of the reflective layer protective film is 2 ⁇ m or less, the columnar crystallinity is not disturbed even if heat treatment is performed.
  • the reflective layer protective film according to the present invention is preferably formed by applying and drying a polymer binder (hereinafter also referred to as “binder”) dissolved or dispersed in a solvent.
  • a polymer binder hereinafter also referred to as “binder”
  • the polymer binder include polyimide or polyimide-containing resin, polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer.
  • Polymer butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, polyester, cellulose derivative (nitrocellulose, etc.), styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, melamine resin , Phenoxy resin, silicon resin, acrylic resin, urea formamide resin, and the like.
  • polyurethane polyester, vinyl chloride copolymer, polyvinyl butyral, and nitrocellulose are preferably used.
  • polyimide or a polyimide-containing resin As the polymer binder according to the present invention, polyimide or a polyimide-containing resin, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose and the like are particularly preferable in terms of close contact with the scintillator layer. Further, a polymer having a glass transition temperature (Tg) of 30 to 100 ° C. is preferable in terms of attaching a film between the deposited crystal and the substrate. From this viewpoint, a polyester resin is particularly preferable. However, if the heat treatment temperature is increased to improve image characteristics such as luminance, a polymer having a Tg of 30 to 100 ° C. may not be able to ensure sufficient heat resistance. In this case, polyimide or a polyimide-containing resin is used.
  • Tg glass transition temperature
  • Solvents that can be used for the preparation of the protective film for the reflective layer include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, lower alcohols such as methanol, ethanol, n-propanol, n-butanol, methylene chloride, ethylene Chlorine-containing hydrocarbons such as chloride, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, aromatic compounds such as toluene, benzene, cyclohexane, cyclohexanone, and xylene, lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, and butyl acetate And ethers such as dioxane, ethylene glycol monoethyl ester, ethylene glycol monomethyl ester, and mixtures thereof.
  • lower alcohols such as methanol, ethanol, n-propanol, n-but
  • the reflective layer protective film according to the present invention may contain a pigment or a dye in order to prevent scattering of light emitted from the scintillator and improve sharpness.
  • substrate As the substrate according to the present invention, various metals, carbon, ⁇ -carbon, a heat-resistant resin substrate and the like can be used, but a heat-resistant resin substrate is particularly preferable in view of image characteristics and cost.
  • the engineering plastics according to the present invention is not particularly limited.
  • polysulfone resin, polyethersulfone resin, polyimide resin, polyetherimide resin, polyamide resin, polyacetal resin, polycarbonate resin, polyethylene terephthalate resin Polybutylene terephthalate resin, aromatic polyester resin, modified polyphenylene oxide resin, polyphenylene sulfide resin, polyether ketone resin and the like are preferably used.
  • These engineering plastics may be used independently and 2 or more types may be used together.
  • a super engineering plastic represented by polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), or the like.
  • the substrate is preferably formed of a resin containing polyimide such as polyimide resin or polyetherimide resin, which is excellent in heat resistance, workability, mechanical strength, and cost.
  • a resin containing polyimide such as polyimide resin or polyetherimide resin
  • the substrate according to the present invention is preferably a substrate having a thickness of 50 to 500 ⁇ m, a flexible substrate, particularly a resin (polymer) film.
  • the “flexible substrate” means a substrate having an elastic modulus (E120) at 120 ° C. of 1000 to 6000 N / mm 2 , and a polymer film containing polyimide or polyethylene naphthalate as the substrate. Is preferred.
  • the “elastic modulus” refers to the stress relative to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS-C2318 and the corresponding stress have a linear relationship using a tensile tester. The slope is obtained. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.
  • Substrate used in the present invention it is preferable elastic modulus at the 120 ° C. as described above (E120) is 1000N / mm 2 ⁇ 6000N / mm 2. More preferably, it is 1200 N / mm 2 to 5000 N / mm 2 .
  • a resin (polymer) film containing polyimide or polyethylene naphthalate is preferable as described above.
  • the image quality is not uniform within the light receiving surface of the flat panel detector due to the influence of deformation of the substrate and warpage during vapor deposition.
  • the substrate a resin (polymer) film with a thickness of 50 to 500 ⁇ m
  • the scintillator panel is transformed into a shape that matches the shape of the planar light receiving element surface, and uniform sharpness is obtained over the entire light receiving surface of the radiation image conversion panel. It is done.
  • a substrate made of various metals such as aluminum can be used.
  • a substrate made of anodized aluminum or the like can be used.
  • a substrate made of anodized aluminum or the like In order to make a substrate made of anodized aluminum or the like, it was immersed as an anode in a solution containing sulfuric acid, phosphoric acid, oxalic acid, chromic acid or sulfamic acid, an organic acid such as benzenesulfonic acid, or a mixture thereof. Current is passed through the aluminum plate.
  • An electrolyte concentration of 1 to 70% by weight can be used at a temperature in the range of 0 to 70 ° C, more preferably at a temperature in the range of 35 to 60 ° C.
  • the anode current density, 1 ⁇ 50A / dm may be changed, also give an anodic oxidation film of 1 ⁇ 8g / m 2 Al 2 O 3 ⁇ H 2 O by changing the voltage in the range of 1 ⁇ 100 V Also good.
  • the anodized aluminum plate may subsequently be rinsed with deionized water at a temperature in the range of 10-80 ° C.
  • post-treatment such as sealing may be applied to the anode surface.
  • Sealing the holes in the aluminum oxide layer formed by anodization is a well-known technique in the technical field of aluminum anodization. This technology is, for example, “Belgsch-Nederlands tijdschiff voor Uppervlacktechtechniken van materialen” (surface technology and material process), Volume 24, January 1980, name “Sealing-kalliteminte-alumine-oxidant-alumino-oxidant-alumine-oxidant-alumino-oxidant-alumino-oxidant Sealing quality and sealing control).
  • the substrate is a resin substrate having a thickness of 50 ⁇ m or more and 500 ⁇ m or less, so that the scintillator panel is deformed into a shape that matches the shape of the planar light receiving element surface, and is uniform over the entire light receiving surface of the radiation image conversion panel. Sharpness is obtained.
  • FIG. 1 is a schematic plan view of a scintillator panel.
  • FIG. 1A is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a four-way seal.
  • FIG. 1B is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a two-way seal.
  • FIG. 1C is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a three-way seal.
  • 1a indicates a scintillator panel.
  • the scintillator panel 1a includes a scintillator plate 101, a first protective film 102a disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101.
  • 102b (see FIG. 2).
  • Reference numerals 103a to 103d denote four sealing portions of the protective film 102a and the second protective film 102b (see FIG. 2), and the sealing portions 103a to 103d are formed outside the peripheral edge portion of the scintillator plate 101. ing.
  • the four-way seal means a state having sealing portions in four directions as shown in the figure.
  • the four-sided seal shown in this figure has a scintillator plate sandwiched between two plate-like protective films of a first protective film 102a and a second protective film 102b (see FIG. 2). It can be produced by sealing.
  • the 1st protective film 102a and the 2nd protective film 102b may differ or may be the same, and can be suitably selected as needed.
  • 1b indicates a scintillator panel.
  • the scintillator panel 1b includes a scintillator plate 101, a first protective film 104 disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101.
  • Reference numerals 105 a and 105 b denote two sealing portions of the protective film 104 and a second protective film (not shown) arranged on the substrate side, and the sealing portions 105 a and 105 b are both outside the peripheral portion of the scintillator plate 101. Is formed.
  • the two-side seal means a state having a sealing portion in two directions as shown in the figure.
  • the two-way seal shown in this figure can be manufactured by sandwiching a scintillator plate between protective films formed into a cylindrical shape by the inflation method and sealing the two sides.
  • the protective films used for the first protective film 104 and the second protective film are the same.
  • 1c represents a scintillator panel.
  • the scintillator panel 1c includes a scintillator plate 101, a first protective film 106 disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101.
  • Reference numerals 107 a to 107 c denote three sealing portions of the first protective film 106 and a second protective film (not shown) arranged on the substrate side. The sealing portions 107 a to 107 c are arranged from the periphery of the scintillator plate 101. Is also formed on the outside.
  • the three-way seal means a state having a sealing portion in three directions as shown in the figure.
  • the three-sided seal shown in this figure can be manufactured by folding a single protective film around the center and sandwiching the scintillator plate between the two protective films that have been molded. .
  • the protective films used for the first protective film 106 and the second protective film are the same.
  • the sealing portion of the two protective films of the first protective film and the second protective film is outside the peripheral portion of the scintillator plate. It is possible to prevent moisture from entering.
  • 1 (a) to 1 (c) is preferably formed on the substrate by a vapor deposition method to be described later.
  • a vapor deposition method an evaporation method, a sputtering method, a CVD method, an ion plating method, or the like can be used.
  • the form of the scintillator panel shown in FIGS. 1 (a) to 1 (c) can be selected depending on the type of scintillator layer of the scintillator plate, the manufacturing apparatus, and the like.
  • FIG. 2 is a schematic cross-sectional view taken along the line AA ′ in FIG. 1A and shows a contact state with the planar light receiving element.
  • FIG. 2A is a diagram showing a schematic enlarged cross-section along AA ′ in FIG. 1A and a contact state with the planar light receiving element.
  • FIG. 2B is a schematic enlarged view of a portion indicated by P in FIG.
  • the scintillator plate 101 has a substrate 101a and a scintillator layer 101b formed on the substrate 101a.
  • Reference numeral 102b denotes a second protective film disposed on the substrate 101a side of the scintillator plate 101.
  • Reference numeral 108 denotes a gap (air layer) formed between the point contact portions E to I that are in partial contact between the first protective film 102a and the scintillator layer 101b.
  • the void portion (air layer) 108 is an air layer, and the relationship between the refractive index of the void portion (air layer) 108 and the refractive index of the first protective film 102a is the refractive index of the protective film 102a >> Air layer) 108 has a refractive index.
  • Reference numeral 109 denotes a gap (air layer) formed between the point contact portions J to O that are in partial contact between the first protective film 102a and the planar light receiving element 201.
  • the void portion (air layer) 109 is an air layer, and the relationship between the refractive index of the void portion (air layer) 109 and the refractive index of the first protective film 102a is the refractive index of the protective film 102a >> Air layer) 109 has a refractive index.
  • the first protective film 102a arranged on the scintillator layer 101b side is not in close contact with the scintillator layer 101b, but is in partial contact with the point contact portions E to I.
  • the point contact portions E to H are 0.1 sites / mm 2 or more with respect to the surface area of the scintillator layer 101b. It is preferable to be 25 locations / mm 2 or less. In the present invention, such a state is referred to as a state in which the first protective film disposed on the scintillator layer side is not substantially adhered.
  • the relationship between the number of point contact portions and the surface area of the scintillator layer is the same as that in this figure.
  • the first protective film 102a is not in a state of close contact with the planar light receiving element 201 but is in partial contact with the point contact portions J to O.
  • the point contact portions J to O are preferably set at 0.1 place / mm 2 or more and 25 places / mm 2 or less with respect to the surface area of the planar light receiving element 201.
  • Sharpness deteriorates when the number of point contact portions between the first protective film 102a and the scintillator layer 101b and the number of point contact portions between the first protective film 102a and the planar light receiving element 201 exceed 25 locations / mm 2 , respectively. It is one of the causes. Even when the number of point contact portions is less than 0.1 / mm 2 , this is one of the causes of deterioration in luminance and sharpness.
  • the X-ray is irradiated to the scintillator panel and the emitted light is read by a flat light receiving element using a CMOS or CCD to obtain signal value data.
  • Power spectrum data for each spatial frequency is obtained by Fourier transforming this data.
  • the number of point contact portions can be known from the position of the peak of the power spectrum. That is, a minute luminance difference occurs between the point portion where the protective layer is in contact and the non-contact portion, and the number of contact points can be known by measuring this period.
  • the total number of point contact portions between the first protective film 102a and the scintillator layer 101b and the number of point contact portions between the first protective film 102a and the planar light receiving element 201 is detected.
  • the first protective film 102a and the scintillator layer 101b are completely adhered by an adhesive, and only the number of contact points of the point contact portion between the first protective film 102a and the planar light receiving element 201 is measured. .
  • the scintillator panel 1a includes a substrate 101a and a scintillator layer 101b, which are a first protective film 102a disposed on the scintillator layer 101b side of the scintillator plate 101 and a second protective film 102b disposed on the substrate 101a side. Is covered with the first protective film 102a in a substantially non-adhered state, and each end of the four sides of the first protective film 102a and the second protective film 102b is sealed.
  • the surface roughness of the surface of the first protective film that comes into contact with the scintillator layer is set to 0.05 to 0 in terms of Ra in consideration of adhesion to the first protective film, sharpness, adhesion to a flat light receiving element, and the like. .8 ⁇ m.
  • the surface shape of the first protective film can be easily adjusted by selecting a resin film to be used or coating a coating film containing an inorganic substance on the surface of the resin film.
  • surface roughness Ra shows the value measured by Tokyo Seimitsu Co., Ltd. Surfcom 1400D.
  • the following method may be mentioned.
  • the thickness of the protective film is preferably 12 ⁇ m or more and 200 ⁇ m or less, more preferably 20 ⁇ m or more and 40 ⁇ m or less, taking into consideration the formation of voids, the scintillator layer protection, sharpness, moisture resistance, workability, and the like.
  • the thickness indicates an average value obtained by measuring 10 points with a stylus stylus thickness meter (PG-01) manufactured by Teclock Co., Ltd.
  • the haze ratio is preferably 3% or more and 40% or less, more preferably 3% or more and 10% or less in consideration of sharpness, radiation image unevenness, manufacturing stability, workability, and the like.
  • a haze rate shows the value measured by Nippon Denshoku Industries Co., Ltd. NDH 5000W.
  • the light transmittance of the protective film is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, scintillator emission wavelength, etc., but a film having a light transmittance of 99% or more is difficult to obtain industrially. Substantially 99% to 70% is preferable.
  • the light transmittance is a value measured with a spectrophotometer (U-1800) manufactured by Hitachi High-Technologies Corporation.
  • the moisture permeability of the protective film is preferably 50 g / m 2 ⁇ day (40 ° C., 90% RH) (measured in accordance with JIS Z0208) or less, more preferably 10 g / m in consideration of the scintillator layer protection, deliquescence and the like. 2 ⁇ day (40 ° C., 90% RH) (measured according to JIS Z0208) or less is preferable.
  • the scintillator plate 101 may be sealed with the first protective film 102a and the second protective film 102b by any known method.
  • the scintillator plate 101 can be efficiently sealed by thermal welding using an impulse sealer.
  • the innermost layer in contact between the protective film 102a and the protective film 102b is a resin film having heat-fusibility.
  • FIG. 3 is a schematic diagram showing the light refraction state in the gap 108 shown in FIG. 2 and the light refraction state in a state where the conventional protective film and the scintillator layer are in close contact with each other.
  • FIG. 3A is a schematic diagram showing a state of light refraction in the gap 108 shown in FIG.
  • FIG. 3B is a schematic diagram showing a state of light refraction in a state where the conventional protective film and the scintillator layer are in close contact with each other.
  • the refractive index of the first protective film 102a and the void (air layer) are present.
  • the relationship with the refractive index of 108 is the refractive index of the first protective film >> the refractive index of the air gap (air layer).
  • the light R to T emitted from the scintillator layer is incident on the protective film without being reflected at the interface between the first protective film 102a and the air gap (air layer) 108 (in a state having no critical angle).
  • the incident light is emitted to the outside without being re-reflected at the interface between the protective film and the air layer due to the optical contrast structure of air layer (low refractive index layer) / protective film / air layer. Can be prevented.
  • the protective film and the scintillator layer are in close contact with each other, the light Z having an angle exceeding the critical angle ⁇ is emitted from the light X to Z emitted from the phosphor surface.
  • the optical non-contrast structure called the air layer increases the proportion of total reflection at the interface. For this reason, it becomes one of the causes that sharpness deteriorates.
  • the scintillator plate when the scintillator plate is sealed with the first protective film and the second protective film, the scintillator layer and the first protective film are not substantially adhered as shown in FIG. It becomes possible to manufacture a scintillator panel that does not deteriorate sharpness by making the protective film and the surface of the planar light receiving element substantially unbonded.
  • the scintillator panel is deformed into a shape suitable for the planar light receiving element surface shape, and a flat panel detector It has been found that uniform sharpness can be obtained over the entire light receiving surface, and the present invention has been achieved.
  • a protective layer with excellent durability can be realized without impeding the light guide effect of the phosphor crystal.
  • FIG. 4 is a schematic view of a vapor deposition apparatus for forming a scintillator layer on a substrate by a vapor deposition method.
  • the vapor deposition apparatus 2 indicates a vapor deposition apparatus.
  • the vapor deposition apparatus 2 includes a vacuum vessel 201, an evaporation source 202 that is provided in the vacuum vessel 201 and deposits vapor on the substrate 3, a substrate holder 203 that holds the substrate 3, and the substrate holder 203 with respect to the evaporation source 202.
  • a substrate rotating mechanism 204 for depositing vapor from the evaporation source 202 by rotating, a vacuum pump 205 for exhausting the vacuum container 201 and introducing the atmosphere, and the like are provided.
  • the evaporation source 202 contains the scintillator layer forming material and is heated by a resistance heating method
  • the evaporation source 202 may be composed of an alumina crucible wound with a heater, or a boat or a heater made of a refractory metal. Also good.
  • the method of heating the scintillator layer forming material may be a method such as heating by an electron beam or heating by high frequency induction other than the resistance heating method, but in the present invention, it is easy to handle with a relatively simple configuration, inexpensive, In addition, the resistance heating method is preferable because it can be applied to a large number of substances.
  • the evaporation source 202 may be a molecular beam source by a molecular source epitaxial method.
  • the support rotating mechanism 204 includes, for example, a rotating shaft 204a that supports the substrate holder 203 and rotates the substrate holder 204, and a motor (not shown) that is disposed outside the vacuum vessel 201 and serves as a driving source for the rotating shaft 204a. It is configured.
  • the substrate holder 203 is preferably provided with a heater (not shown) for heating the substrate 3.
  • a heater not shown
  • the adsorbed material on the surface of the substrate 3 is separated and removed, and the generation of an impurity layer between the surface of the substrate 3 and the scintillator layer forming material is prevented.
  • the film quality can be adjusted.
  • a shutter (not shown) that blocks the space from the evaporation source 202 to the substrate 3 may be provided between the substrate 3 and the evaporation source 202. It is possible to prevent substances other than the object attached to the surface of the scintillator layer forming material from evaporating at the initial stage of vapor deposition and adhering to the substrate 3 by the shutter.
  • the support 3 is attached to the substrate holder 203.
  • the vacuum vessel 201 is evacuated.
  • the substrate holder 203 is rotated with respect to the evaporation source 202 by the support rotating mechanism 204, and when the vacuum container 201 reaches a vacuum degree capable of vapor deposition, the scintillator layer forming material is evaporated from the heated evaporation source 202, A phosphor is grown on the surface of the substrate 3 to a desired thickness.
  • the distance between the substrate 3 and the evaporation source 202 is preferably set to 100 to 1500 mm, more preferably 200 to 1000 mm.
  • the scintillator layer forming material used as the evaporation source may be processed into a tablet shape by pressure compression or may be in a powder state. Further, instead of the scintillator layer forming material, a raw material or a raw material mixture may be used. It is preferable that an inert gas such as argon is introduced into the vacuum vessel 201 during vapor deposition, and the inside of the vacuum vessel 201 is maintained in a vacuum atmosphere of 0.001 to 5 Pa, more preferably 0.01 to 2 Pa. .
  • the temperature of the substrate 3 on which the phosphor layer is formed is preferably set to room temperature 25 to 50 ° C. at the start of vapor deposition, and is preferably set to 100 to 300 ° C., more preferably 150 to 250 ° C. during vapor deposition. preferable.
  • the radiation image conversion panel (also referred to as “radiation image detector” or “radiation flat panel detector”) of the present invention is a radiation image conversion panel having a scintillator panel and a planar light receiving element as a basic configuration. Like As a result, the planar light receiving element surface converts the light emitted from the scintillator panel into electric charges, whereby the image can be converted into digital data.
  • the scintillator panel is placed on the plane light receiving element surface. At this time, it is preferable that the scintillator panel is not physically bonded to the plane light receiving element surface.
  • the phosphor is directly vapor-deposited on the surface of the planar light receiving element to form a scintillator panel in which the planar light receiving element and the scintillator layer are integrated.
  • the average surface roughness (Ra) of the planar light receiving element according to the present invention is required to be 0.001 to 0.5 ⁇ m. For this reason, after forming a light receiving element on the glass surface, an organic resin film such as polyester or acrylic is formed on the surface, and the surface roughness is controlled by a photoetching method so as to satisfy the requirements.
  • the surface average roughness (Ra) of the planar light receiving element is preferably 0.001 to 0.1 ⁇ m, and more preferably 0.001 to 0.05 ⁇ m.
  • the radiation image conversion panel of the present invention is preferably in such a mode that the scintillator panel is pressed and adhered to the planar light receiving element by an elastic member (for example, sponge, spring, etc.).
  • an elastic member for example, sponge, spring, etc.
  • the scintillator panel is in a state in which the scintillator panel is in close contact with the planar light receiving element and the periphery thereof is sealed with a close seal member by reducing the gas in the gap between the scintillator panel and the planar light receiving element.
  • the close seal member is preferably an ultraviolet curable resin.
  • the scintillator panel has a scintillator layer and the scintillator layer is in direct contact with the planar light receiving element.
  • the ultraviolet curable resin is not particularly limited and can be appropriately selected from those conventionally used.
  • This ultraviolet curable resin contains a photopolymerizable prepolymer, a photopolymerizable monomer, a photopolymerization initiator or a photosensitizer.
  • Examples of the photopolymerizable prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate. These photopolymerizable prepolymers may be used alone or in combination of two or more.
  • Examples of the photopolymerizable monomer include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate.
  • urethane acrylate as the prepolymer and dipentaerythritol hexa (meth) acrylate as the monomer.
  • photopolymerization initiator examples include acetophenones, benzophenones, ⁇ -amyloxime esters, tetramethylchuram monosulfide, thioxanthones, and the like. Further, n-butylamine, triethylamine, poly-n-butylphosphine and the like can be mixed and used as a photosensitizer.
  • FIG. 5 is a partially broken perspective view showing a schematic configuration of the radiation image conversion panel 100.
  • FIG. 6 is an enlarged sectional view of the radiation image conversion panel 100.
  • the radiation image conversion panel 100 includes an imaging panel 51, a control unit 52 that controls the operation of the radiation image conversion panel 100, a rewritable dedicated memory (for example, a flash memory), and the like.
  • a memory unit 53 that is a storage unit that stores an image signal output from the power source unit 54, a power supply unit 54 that is a power supply unit that supplies power necessary to obtain the image signal by driving the imaging panel 51, and the like. It is provided inside the body 55.
  • the housing 55 includes a communication connector 56 for performing communication from the radiation image conversion panel 100 to the outside as necessary, an operation unit 57 for switching the operation of the radiation image conversion panel 100, and preparation for radiographic image capturing.
  • a display unit 58 that indicates completion or a predetermined amount of image signal has been written in the memory unit 53 is provided.
  • the radiation image conversion panel 100 is provided with the power supply unit 54 and the memory unit 53 for storing the image signal of the radiation image, and the radiation image detector 100 is detachable via the connector 56, the radiation image conversion panel. It can be set as the portable structure which can carry 100.
  • the imaging panel 51 includes a radiation scintillator panel 10 and an output substrate 20 that absorbs electromagnetic waves from the scintillator panel 10 and outputs an image signal.
  • the scintillator panel 10 is disposed on the radiation irradiation surface side and is configured to emit an electromagnetic wave corresponding to the intensity of incident radiation.
  • the output substrate 20 is provided on the surface opposite to the radiation irradiation surface of the scintillator panel 10, and includes a diaphragm 20a, a photoelectric conversion element 20b, an image signal output layer 20c, and a substrate 20d in order from the radiation scintillator panel 10 side. ing.
  • the diaphragm 20a is used to separate the radiation scintillator panel 10 from other layers.
  • the photoelectric conversion element 20 b includes a transparent electrode 21, a charge generation layer 22 that is excited by electromagnetic waves that have passed through the transparent electrode 21 to enter the light, and generates a charge, and a counter electrode 23 that is a counter electrode for the transparent electrode 21.
  • the transparent electrode 21, the charge generation layer 22, and the counter electrode 23 are arranged in this order from the diaphragm 20a side.
  • the transparent electrode 21 is an electrode that transmits an electromagnetic wave that is photoelectrically converted, and is formed using a conductive transparent material such as indium tin oxide (ITO), SnO 2 , or ZnO.
  • ITO indium tin oxide
  • SnO 2 SnO 2
  • ZnO ZnO
  • the charge generation layer 22 is formed in a thin film on one surface side of the transparent electrode 21 and contains an organic compound that separates charges by light as a compound capable of photoelectric conversion. Each of them contains a conductive compound as an electron acceptor. In the charge generation layer 22, when an electromagnetic wave is incident, the electron donor is excited to emit electrons, and the emitted electrons move to the electron acceptor, and charge, that is, holes and electrons, are transferred into the charge generation layer 22.
  • examples of the conductive compound as the electron donor include a p-type conductive polymer compound.
  • examples of the p-type conductive polymer compound include polyphenylene vinylene, polythiophene, poly (thiophene vinylene), polyacetylene, polypyrrole, Those having a basic skeleton of polyfluorene, poly (p-phenylene) or polyaniline are preferred.
  • Examples of the conductive compound as the electron acceptor include an n-type conductive polymer compound.
  • the n-type conductive polymer compound preferably has a polypyridine basic skeleton, and in particular, poly (p-pyridylvinylene). Those having the following basic skeleton are preferred.
  • the film thickness of the charge generation layer 22 is preferably 10 nm or more (particularly 100 nm or more) from the viewpoint of securing the amount of light absorption, and is preferably 1 ⁇ m or less (particularly 300 nm or less) from the viewpoint that the electric resistance does not become too large.
  • the counter electrode 23 is disposed on the opposite side of the surface of the charge generation layer 22 where the electromagnetic wave is incident.
  • the counter electrode 23 can be selected and used from, for example, a general metal electrode such as gold, silver, aluminum, and chromium, or the transparent electrode 21. Small (4.5 eV or less) metals, alloys, electrically conductive compounds and mixtures thereof are preferably used as electrode materials.
  • a buffer layer may be provided between each electrode (transparent electrode 21 and counter electrode 23) sandwiching the charge generation layer 22 so as to act as a buffer zone so that the charge generation layer 22 and these electrodes do not react.
  • the buffer layer include lithium fluoride and poly (3,4-ethylenedioxythiophene), poly (4-styrenesulfonate), 2,9-dimethyl-4,7-diphenyl [1,10] phenanthroline, and the like. Formed using.
  • the image signal output layer 20c performs accumulation of charges obtained by the photoelectric conversion element 20b and output of a signal based on the accumulated charges. Charge for accumulating the charges generated by the photoelectric conversion element 20b for each pixel.
  • the capacitor 24 is a storage element
  • the transistor 25 is an image signal output element that outputs the stored charge as a signal.
  • a TFT Thin Film Transistor
  • This TFT may be an inorganic semiconductor type used in a liquid crystal display or the like or an organic semiconductor, and is preferably a TFT formed on a plastic film.
  • TFTs formed on plastic films amorphous silicon-based TFTs are known, but in addition, FSA (Fluidic Self Assembly) technology developed by Alien Technology in the United States, that is, microfabricated with single crystal silicon.
  • TFTs may be formed on a flexible plastic film by arranging CMOS (Nanoblocks) on an embossed plastic film.
  • CMOS Nemoblocks
  • Science, 283, 822 (1999) and Appl. Phys. It may be a TFT using an organic semiconductor as described in documents such as Lett, 771488 (1998), Nature, 403, 521 (2000).
  • a TFT manufactured by the FSA technique and a TFT using an organic semiconductor are preferable, and a TFT using an organic semiconductor is particularly preferable. If this organic semiconductor is used to form a TFT, equipment such as a vacuum deposition apparatus is not required as in the case where a TFT is formed using silicon, and the TFT can be formed using printing technology or inkjet technology. Is cheaper. Further, since the processing temperature can be lowered, it can be formed on a plastic substrate that is weak against heat.
  • the transistor 25 accumulates electric charges generated in the photoelectric conversion element 20b and is electrically connected to a collecting electrode (not shown) serving as one electrode of the capacitor 24.
  • the capacitor 24 accumulates charges generated by the photoelectric conversion element 20 b and reads the accumulated charges by driving the transistor 25. That is, by driving the transistor 25, a signal for each pixel of the radiation image can be output.
  • the substrate 20d functions as a support for the imaging panel 51, and can be made of the same material as the substrate 1.
  • the radiation incident on the radiation image conversion panel 100 enters the imaging panel 51 from the scintillator panel 10 side toward the substrate 20d side. Then, the radiation incident on the radiation scintillator panel 10 is absorbed by the scintillator layer 2 in the scintillator panel 10 and emits an electromagnetic wave corresponding to its intensity.
  • the electromagnetic waves entering the output substrate 20 pass through the diaphragm 20a and the transparent electrode 21 of the output substrate 20 and reach the charge generation layer 22. Then, the electromagnetic wave is absorbed in the charge generation layer 22 and a hole-electron pair (charge separation state) is formed according to the intensity.
  • the generated electric charges are transported to different electrodes (transparent electrode film and conductive layer) by an internal electric field generated by application of a bias voltage by the power supply unit 54, and a photocurrent flows.
  • the holes carried to the counter electrode 23 side are accumulated in the capacitor 24 of the image signal output layer 20c.
  • the accumulated holes output an image signal when the transistor 25 connected to the capacitor 24 is driven, and the output image signal is stored in the memory unit 53.
  • the scintillator panel 10 since the scintillator panel 10 is provided, the photoelectric conversion efficiency can be increased, the SN ratio at the time of low-dose imaging in a radiation image is improved, and image unevenness and linear noise are improved. Can be prevented.
  • the radiographic image conversion panel of the present invention can be suitably used in an X-ray imaging system of an aspect in which a radiographic image is read by placing X-rays on a portable container.
  • the portable container can be inserted under the patient on the bed at the time of imaging, and can be used in various imaging modes due to its small size.
  • the portable container is easy to carry, it is susceptible to dropping and impact, and in this case, image blurring due to displacement and air entering the scintillator and TFT tends to occur.
  • the adhesiveness of a scintillator and TFT improves, it is preferable when arrange
  • Example 1 Preparation of scintillator sheet
  • substrate As a substrate, a polyimide substrate (90 mm ⁇ 90 mm) having a thickness of 0.25 mm and subjected to plasma treatment in Ar gas and a glass substrate having a thickness of 0.5 mm were prepared.
  • Fluorescent material (CsI: 0.003 Tl) was filled in a resistance heating crucible, a polyimide substrate was placed on the support holder, and the distance between the resistance heating crucible and the substrate was adjusted to 400 mm. Subsequently, the inside of the vapor deposition apparatus was once evacuated, Ar gas was introduced and the degree of vacuum was adjusted to 0.5 Pa, and then the substrate temperature was maintained at 150 ° C. while rotating the substrate at a speed of 10 rpm. Next, the resistance heating crucible was heated to deposit the phosphor, and the deposition was terminated when the thickness of the phosphor layer reached 400 ⁇ m.
  • a polypropylene film (PP) having a thickness of 30 ⁇ m with a surface roughness changed as shown in Table 1 was prepared. 1 to 5 and 7 to 15. The surface roughness was adjusted by appropriately selecting the PP to be used from commercially available PP. (The surface roughness of the PP film was the same on both sides) The same protective film on the phosphor surface side was used as the protective film on the substrate side of the scintillator sheet.
  • the surface roughness was measured with Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd. (Cutoff value is 0.8mm) (Production of scintillator panel)
  • the prepared scintillator sheet was prepared from the prepared protective film No. 1 to 5 and 7 to 15 were used and sealed in the form shown in FIG. 1 to 5 and 7 to 15. Fusion was performed such that the distance from the fusion part to the peripheral part of the scintillator sheet was 1 mm.
  • the impulse sealer used for the fusion was a 3 mm wide heater.
  • a sponge sheet was placed on the radiation incident side (the side without the phosphor) of the radiation incident window carbon plate and the scintillator panel, and both were fixed by lightly pressing the plane light receiving element surface and the scintillator panel.
  • Evaluation criteria 6: There is no unevenness or it cannot be visually confirmed.
  • Unevenness exists but the area is 20% or less of the image part 4: Unevenness exists and the area is 20% to 40% of the image part, but can be used 3: Unevenness exists and the area is 40% to 60% of the image area 2: There is unevenness, and the area is 60% to 80% of the image area 1: There is unevenness, and the area is 80% or more of the image portion and cannot be used.

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Abstract

Disclosed is a radiation image conversion panel having improved adhesion between a scintillator panel and a planar light-receiving element surface, wherein lowering of sharpness (MTF value) or image variations are prevented. A radiographic apparatus using the radiation image conversion panel is also disclosed. The radiation image conversion panel comprises a scintillator panel and a planar light-receiving element, and is characterized in that the scintillator panel has a surface roughness (Ra) of 0.01-3.0 µm in a surface facing the planar light-receiving element, and the planar light-receiving element has a surface roughness (Ra) of 0.001-0.5 µm in a surface facing the scintillator panel.

Description

放射線画像変換パネルとそれを用いたＸ線撮影システムRadiation image conversion panel and X-ray imaging system using the same
　本発明は、シンチレータパネルと平面受光素子を備えた放射線画像変換パネルとそれを用いたＸ線撮影システムの画像特性（鮮鋭性及び画像ムラ）の改良技術に関する。 The present invention relates to a radiation image conversion panel provided with a scintillator panel and a planar light receiving element, and a technique for improving image characteristics (sharpness and image unevenness) of an X-ray imaging system using the same.
　従来、Ｘ線画像のような放射線画像は、医療現場において病状の診断に広く用いられている。特に、増感紙－フィルム系による放射線画像は、長い歴史のなかで高感度化と高画質化が図られた結果、高い信頼性と優れたコストパフォーマンスを併せ持った撮像システムとして、いまなお、世界中の医療現場で用いられている。しかしながらこれら画像情報はいわゆるアナログ画像情報であって、近年発展を続けているデジタル画像情報のような、自由な画像処理や瞬時の電送が出来ない。 Conventionally, radiation images such as X-ray images have been widely used for medical diagnosis in medical settings. In particular, radiographic images using intensifying screens and film systems have been developed as an imaging system that combines high reliability and excellent cost performance as a result of high sensitivity and high image quality in the long history. Used in the medical field. However, the image information is so-called analog image information, and free image processing and instantaneous electric transmission cannot be performed like the digital image information that has been developed in recent years.
　そして、近年ではコンピューテッドラジオグラフィ（ＣＲ）やフラットパネル型の放射線ディテクタ（ＦＰＤ）等に代表されるデジタル方式の放射線画像検出装置が登場している。これらは、デジタルの放射線画像が直接得られ、陰極管や液晶パネル等の画像表示装置に画像を直接表示することが可能なので、必ずしも写真フィルム上への画像形成が必要なものではない。その結果、これらのデジタル方式のＸ線画像検出装置は、銀塩写真方式による画像形成の必要性を低減させ、病院や診療所での診断作業の利便性を大幅に向上させている。 In recent years, digital radiological image detection devices represented by computed radiography (CR), flat panel type radiation detectors (FPD) and the like have appeared. In these, since a digital radiographic image is directly obtained and an image can be directly displayed on an image display device such as a cathode tube or a liquid crystal panel, image formation on a photographic film is not necessarily required. As a result, these digital X-ray image detection devices reduce the need for image formation by the silver halide photography method, and greatly improve the convenience of diagnosis work in hospitals and clinics.
　Ｘ線画像のデジタル技術の一つとしてコンピューテッド・ラジオグラフィ（ＣＲ）が現在医療現場で受け入れられている。そして、更に新たなデジタルＸ線画像技術として、例えば雑誌Ｐｈｙｓｉｃｓ　Ｔｏｄａｙ，１９９７年１１月号２４頁のジョン・ローランズ論文“Ａｍｏｒｐｈｏｕｓ　Ｓｅｍｉｃｏｎｄｕｃｔｏｒ　Ｕｓｈｅｒ　ｉｎ　Ｄｉｇｉｔａｌ　Ｘ－ｒａｙ　Ｉｍａｇｉｎｇ”や、雑誌ＳＰＩＥの１９９７年３２巻２頁のエル・イー・アントヌクの論文“Ｄｅｖｅｌｏｐｍｅｎｔ　ｏｆ　ａ　Ｈｉｇｈ　Ｒｅｓｏｌｕｔｉｏｎ，Ａｃｔｉｖｅ　Ｍａｔｒｉｘ，Ｆｌａｔ－Ｐａｎｅｌ　Ｉｍａｇｅｒ　ｗｉｔｈ　Ｅｎｈａｎｃｅｄ　Ｆｉｌｌ　Ｆａｃｔｏｒ”等に記載された、薄膜トランジスタ（ＴＦＴ）を用いた平板Ｘ線検出装置（ＦＰＤ）が開発されている。 * Computed radiography (CR) is currently accepted in the medical field as one of the digital technologies for X-ray images. Further, as new digital X-ray imaging techniques, for example, the magazine Physics Today, November 1997, page 24, John Laurans' paper “Amorphous Semiconductor User in Digital X-ray Imaging”, magazine SPIE Vol. 32, 1997. Thin-film transistors (TFTs) using thin-film transistors (TFTs) using thin-film transistors (TFTs), which are described in El E. Antonuk's paper “Development of a High Resolution, Active Matrix, Flat-Panel Imager with Enhanced Fill Factor”, etc. Has been developed.
　放射線を可視光に変換するために、放射線により発光する特性を有する蛍光体で作られたシンチレータプレートが使用されるが、低線量の撮影においてのＳＮ比を向上するためには、発光効率の高いシンチレータプレートを使用することが必要になってくる。一般にシンチレータプレートの発光効率は、蛍光体層の厚さ、蛍光体のＸ線吸収係数によって決まるが、蛍光体層の厚さは厚くすればするほど、蛍光体層内での発光光の散乱が発生し、鮮鋭性は低下する。そのため、画質に必要な鮮鋭性を決めると、膜厚が決定する。 In order to convert radiation into visible light, a scintillator plate made of a phosphor having the property of emitting light by radiation is used. In order to improve the S / N ratio in low-dose imaging, the luminous efficiency is high. It will be necessary to use scintillator plates. In general, the light emission efficiency of the scintillator plate is determined by the thickness of the phosphor layer and the X-ray absorption coefficient of the phosphor. The thicker the phosphor layer, the more scattered the emitted light in the phosphor layer. Occurs and sharpness decreases. Therefore, when the sharpness necessary for the image quality is determined, the film thickness is determined.
　なかでもヨウ化セシウム（ＣｓＩ）はＸ線から可視光に対する変更率が比較的高く、蒸着によって容易に蛍光体を柱状結晶構造に形成出来るため、光ガイド効果により結晶内での発光光の散乱が抑えられ、蛍光体層の厚さを厚くすることが可能であった。 In particular, cesium iodide (CsI) has a relatively high rate of change from X-rays to visible light, and phosphors can be easily formed into a columnar crystal structure by vapor deposition. Therefore, it was possible to increase the thickness of the phosphor layer.
　しかしながら、ＣｓＩをベースとしたシンチレータ（蛍光体層）は潮解性があり、経時で特性が劣化するという欠点がある。この様な経時劣化を防止するためにＣｓＩをベースとしたシンチレータ（蛍光体層）の表面に防湿性保護層を形成することが提案されている。例えば、ポリパラキシリレン樹脂によりシンチレータ層（「蛍光体層」ともいう。）の上部、側面及び基板のシンチレータ層外周部を覆う方法が知られている（例えば、特許文献１を参照。）。 However, the scintillator (phosphor layer) based on CsI has a deliquescent property and has a drawback that the characteristics deteriorate with time. In order to prevent such deterioration over time, it has been proposed to form a moisture-proof protective layer on the surface of a scintillator (phosphor layer) based on CsI. For example, there is known a method of covering the upper and side surfaces of the scintillator layer (also referred to as “phosphor layer”) and the outer periphery of the scintillator layer of the substrate with polyparaxylylene resin (see, for example, Patent Document 1).
　しかしながら特許文献１に記載のポリパラキシリレン樹脂は防湿性が弱く、十分に蛍光体層を保護出来ないこと及びシンチレータ層を構成している柱状結晶の間隙にもポリパラキシリレン樹脂が進入し、光ガイド効果を阻害するという欠点があった。 However, the polyparaxylylene resin described in Patent Document 1 is weak in moisture resistance, cannot sufficiently protect the phosphor layer, and the polyparaxylylene resin enters the gaps between the columnar crystals constituting the scintillator layer. The light guide effect was hindered.
　又、水分透過率１．２ｇ／ｍ２・日未満の透明樹脂フィルムでシンチレータ層の少なくとも支持体に対向する側の反対側と、側面とを覆う方法が知られている（例えば、特許文献２を参照。）。 Further, a method is known in which a transparent resin film having a moisture permeability of less than 1.2 g / m 2 · day covers at least the side opposite to the side of the scintillator layer facing the support and the side surface (for example, Patent Document 2). See).
　しかしながら特許文献２に記載の方法では、ポリプロプレンやポリエチレンテレフタレートの如き透明な有機高分子フィルムを保護層として蛍光体層の上に密着した状態で設置した場合は高い防湿性が得られるものの、鮮鋭性が低下するという致命的な欠点があり、これを回避するためにはフィルムの厚みを５μｍ以下にする必要があり、蛍光体層を化学的な変質あるいは物理的な衝撃から保護するには不十分なものとなり、実質的に保護層として使用出来ないのが実情であった。また、シンチレータパネルを平面受光素子面上に配置するにあたっては、例えば、特開平５－３１２９６１号公報及び特開平６－３３１７４９号公報の方法があるがこれらは生産効率が悪く、シンチレータパネルと平面受光素子面での鮮鋭性の劣化は避けられない。また特開２００２－１１６２５８号公報では、保護層としてポリパラキシリレン等の柔軟な保護層を使用した例が示されているが、柔軟な有機膜を保護層とした場合、保護層と平面受光素子面が密着してしまう為、後述する理由によりシンチレータからの発光光が保護層内で伝播し鮮鋭性が劣化する。 However, in the method described in Patent Document 2, when a transparent organic polymer film such as polypropylene or polyethylene terephthalate is installed as a protective layer in close contact with the phosphor layer, high moisture resistance is obtained, but sharp In order to avoid this, it is necessary to reduce the thickness of the film to 5 μm or less, and it is not possible to protect the phosphor layer from chemical alteration or physical impact. The actual situation was that it was sufficient and could not be practically used as a protective layer. Further, for example, there are methods disclosed in Japanese Patent Application Laid-Open Nos. 5-329661 and 6-331749 for arranging the scintillator panel on the surface of the planar light receiving element. Deterioration of sharpness on the element surface is inevitable. Japanese Patent Application Laid-Open No. 2002-116258 shows an example in which a flexible protective layer such as polyparaxylylene is used as the protective layer. However, when a flexible organic film is used as the protective layer, the protective layer and the planar light receiving layer are used. Since the element surfaces are in close contact with each other, the light emitted from the scintillator propagates in the protective layer for the reason described later, and the sharpness deteriorates.
　また、従来、気相法によるシンチレータの製造方法としては、アルミやアモルファスカーボンなど剛直な基板上に蛍光体層を形成し、その上にシンチレータの表面全体を保護膜で被覆させることが一般的である（例えば特許文献３参照）。 Conventionally, as a manufacturing method of a scintillator by a vapor phase method, a phosphor layer is generally formed on a rigid substrate such as aluminum or amorphous carbon, and the entire surface of the scintillator is covered with a protective film. Yes (see, for example, Patent Document 3).
　しかしながら、自由に曲げることのできないこれらの基板上に蛍光体層を形成した場合、シンチレータパネルと平面受光素子面を貼り合せる際に、基板の変形や蒸着時の反りなどの影響を受け、フラットパネルディテクタの受光面内で均一な画質特性が得られないという欠点がある。この問題は近年のフラットパネルディテクタの大型化に伴い深刻化してきている。 However, when a phosphor layer is formed on these substrates that cannot be bent freely, when the scintillator panel and the planar light receiving element surface are bonded, the flat panel is affected by deformation of the substrate and warpage during vapor deposition. There is a drawback that uniform image quality characteristics cannot be obtained within the light receiving surface of the detector. This problem has become more serious with the recent increase in the size of flat panel detectors.
　この問題を回避するために撮像素子上に直接、蒸着でシンチレータを形成する方法や、鮮鋭性の低いが、可撓性を有する医用増感紙などをシンチレータの代用として用いることが一般的に行われている。 In order to avoid this problem, it is common practice to use a scintillator as a substitute for the scintillator, such as a method of forming a scintillator directly by vapor deposition on the image sensor or a low-sharp but flexible medical intensifying screen. It has been broken.
　また、シンチレータと光電変換素子部を減圧下で張り合わせ、周囲をシールする方法や、シンチレータと光電変換素子部を透明樹脂で貼り合わせる方法等が開示されている（例えば特許文献４及び５参照）。
特開２０００－２８４０５３号公報 特開２００５－３０８５８２号公報 特許第３５６６９２６号明細書 特開平９－２３００５４号公報 特開２００７－２８５７０９号公報 In addition, a method of bonding the scintillator and the photoelectric conversion element portion under reduced pressure and sealing the periphery, a method of bonding the scintillator and the photoelectric conversion element portion with a transparent resin, and the like are disclosed (for example, see Patent Documents 4 and 5).
JP 2000-284053 A JP 2005-308582 A Japanese Patent No. 3669926 Japanese Patent Laid-Open No. 9-230054 JP 2007-285709 A
　しかしながら、上記開示方法では、シンチレータと光電変換素子部との間に空気だまりができやすい、また、隙間が大きくなりやすいこと等によりＭＴＦの低下や画像ムラを発生させやすいという問題がある。 However, the above disclosed method has a problem that air is easily trapped between the scintillator and the photoelectric conversion element section, and that the gap is likely to be large, so that MTF is lowered and image unevenness is likely to occur.
　本発明は、上記問題・状況に鑑み成されたものであり、その解決課題は、シンチレータパネルと平面受光素子面の密着性を改良し、鮮鋭性（ＭＴＦ）の低下や画像ムラの発生を防止した放射線画像変換パネルを提供することである。また、これを用いたＸ線撮影システムを提供することである。 The present invention has been made in view of the above-described problems and situations, and its solution is to improve the adhesion between the scintillator panel and the planar light-receiving element surface to prevent sharpness (MTF) degradation and image unevenness. And providing a radiation image conversion panel. Moreover, it is providing the X-ray imaging system using this.
　発明者らは、上記課題を解決すべく鋭意検討を加えた結果、シンチレータパネルと平面受光素子面の表面平均粗さを特定範囲内に制御することで問題を解決することができることを見出し、本発明に至った。すなわち、本発明に係る上記課題は、以下の手段により解決される。 As a result of earnest studies to solve the above problems, the inventors have found that the problem can be solved by controlling the surface average roughness of the scintillator panel and the planar light receiving element surface within a specific range. Invented. That is, the said subject which concerns on this invention is solved by the following means.
　１．シンチレータパネルと平面受光素子を備えた放射線画像変換パネルであって、当該シンチレータパネルの平面受光素子と対向する側の表面平均粗さ（Ｒａ）が０．０１～３．０μｍ、かつ当該平面受光素子のシンチレータパネルと対向する側の表面平均粗さ（Ｒａ）が０．００１～０．５μｍであることを特徴とする放射線画像変換パネル。 1. A radiation image conversion panel including a scintillator panel and a planar light receiving element, wherein the surface average roughness (Ra) on the side of the scintillator panel facing the planar light receiving element is 0.01 to 3.0 μm, and the planar light receiving element A radiation image conversion panel having an average surface roughness (Ra) on the side facing the scintillator panel of 0.001 to 0.5 μm.
　２．前記シンチレータパネルが、前記平面受光素子に弾力部材により押しつけられ密着していることを特徴とする前記１に記載の放射線画像変換パネル。 2. 2. The radiation image conversion panel as described in 1 above, wherein the scintillator panel is pressed against and adhered to the planar light receiving element by an elastic member.
　３．前記シンチレータパネルが、当該シンチレータパネルと前記平面受光素子との間隙の気体の減圧により、当該平面受光素子に密着し、かつ周辺を密着シール部材でシールされていることを特徴とする前記１に記載の放射線画像変換パネル。 3. 2. The scintillator panel according to 1 above, wherein the scintillator panel is in close contact with the planar light receiving element and the periphery thereof is sealed with a tight seal member by depressurization of the gas in the gap between the scintillator panel and the planar light receiving element. Radiation image conversion panel.
　４．前記シンチレータパネルが、可撓性を有していることを特徴とする前記１から３のいずれか一項に記載の放射線画像変換パネル。 4. 4. The radiation image conversion panel according to any one of 1 to 3, wherein the scintillator panel has flexibility.
　５．前記密着シール部材が、紫外線硬化型樹脂であることを特徴とする前記３又は４に記載の放射線画像変換パネル。 5. 5. The radiation image conversion panel as described in 3 or 4 above, wherein the contact seal member is an ultraviolet curable resin.
　６．前記シンチレータパネルがシンチレータ層を有し、かつ当該シンチレータ層が平面受光素子に直接的に密着していることを特徴とする前記１から５のいずれか一項に記載の放射線画像変換パネル。 6. The radiation image conversion panel according to any one of 1 to 5, wherein the scintillator panel has a scintillator layer, and the scintillator layer is in direct contact with the planar light receiving element.
　７．前記シンチレータ層が、ヨウ化セシウム（ＣｓＩ）を主成分として含有することを特徴とする前記６に記載の放射線画像変換パネル。 7. 7. The radiation image conversion panel as described in 6 above, wherein the scintillator layer contains cesium iodide (CsI) as a main component.
　８．前記シンチレータ層が、気相堆積法により形成された蛍光体柱状結晶であることを特徴とする前記６又は７に記載の放射線画像変換パネル。 8. 8. The radiation image conversion panel according to 6 or 7, wherein the scintillator layer is a phosphor columnar crystal formed by a vapor deposition method.
　９．前記１から８のいずれか一項に記載の放射線画像変換パネルを可搬性容器に配置し、Ｘ線を曝射し、放射線画像の読み取りを行うことを特徴とするＸ線撮影システム。 9. An X-ray imaging system, wherein the radiation image conversion panel according to any one of 1 to 8 is disposed in a portable container, X-rays are irradiated, and a radiation image is read.
　本発明の上記手段により、シンチレータパネルと平面受光素子面の密着性を改良し、鮮鋭性（ＭＴＦ）の低下や画像ムラの発生を防止した放射線画像変換パネルを提供することができる。また、これを用いたＸ線撮影システムを提供することができる。 By the above-mentioned means of the present invention, it is possible to provide a radiation image conversion panel that improves the adhesion between the scintillator panel and the planar light receiving element surface and prevents sharpness (MTF) degradation and image unevenness. In addition, an X-ray imaging system using the same can be provided.
シンチレータパネルの概略平面図Schematic plan view of scintillator panel 図１（ａ）のＡ－Ａ′に沿った概略断面図Schematic cross-sectional view along AA 'in FIG. 図２に示される空隙部における光の屈折の状態と、従来の保護フィルムとシンチレータ層（蛍光体層）とが密着した状態における光の屈折の状態を示す模式図Schematic diagram showing the state of light refraction in the gap shown in FIG. 2 and the state of light refraction in a state where the conventional protective film and the scintillator layer (phosphor layer) are in close contact with each other. 基板の上に気相堆積法でシンチレータ層を形成する蒸着装置の模式図Schematic diagram of a vapor deposition device that forms a scintillator layer on a substrate by vapor deposition. 放射線画像変換パネルの概略構成を示す一部破断斜視図Partially broken perspective view showing schematic configuration of radiation image conversion panel 放射線画像変換パネルの拡大断面図Expanded sectional view of the radiation image conversion panel
符号の説明Explanation of symbols
　１ａ～１ｃ　シンチレータパネル
　１００　放射線画像変換パネル
　１０１　シンチレータプレート
　１０１ａ、３　基板
　１０１ｂ　シンチレータ層（蛍光体層）
　１０１ｃ　反射層
　１０１ｄ　防蝕反射層
　１０２ａ、１０４　第１保護フィルム
　１０２ｂ　第２保護フィルム
　１０３ａ～１０３ｄ、１０５ａ、１０５ｂ、１０７ａ～１０７ｃ　封止部
　１０８　空隙部（空気層）
　Ｅ～Ｈ　点接触部分
　Ｒ～Ｔ、Ｘ～Ｚ　光
　２　蒸着装置
　２０１　真空容器
　２０２　蒸発源
　２０３　基板ホルダ
　２０４　基板回転機構
　２０５　真空ポンプ 1a to 1c scintillator panel 100 radiation image conversion panel 101 scintillator plate 101a, 3 substrate 101b scintillator layer (phosphor layer)
101c Reflective layer 101d Corrosion-resistant reflective layer 102a, 104 First protective film 102b Second protective film 103a-103d, 105a, 105b, 107a-107c Sealing part 108 Air gap part (air layer)
E to H Point contact portion R to T, X to Z Light 2 Evaporation apparatus 201 Vacuum vessel 202 Evaporation source 203 Substrate holder 204 Substrate rotation mechanism 205 Vacuum pump
　本発明の放射線画像変換パネルは、シンチレータパネルと平面受光素子を備えた放射線画像変換パネルであって、当該シンチレータパネルの平面受光素子と対向する側の表面平均粗さ（Ｒａ）が０．０１～３．０μｍ、かつ当該平面受光素子のシンチレータパネルと対向する側の表面平均粗さ（Ｒａ）が０．００１～０．５μｍであることを特徴とする。この特徴は、請求の範囲第１項から第９項に係る発明に共通する技術的特徴である。 The radiation image conversion panel of the present invention is a radiation image conversion panel including a scintillator panel and a planar light receiving element, and has a surface average roughness (Ra) on the side facing the planar light receiving element of the scintillator panel of 0.01 to The surface average roughness (Ra) of the flat light-receiving element facing the scintillator panel is 0.001 to 0.5 μm. This feature is a technical feature common to the inventions according to claims 1 to 9.
　本発明の実施態様としては、シンチレータパネルの表面平均粗さ（Ｒａ）は、０．０１～１．０μｍであることが好ましく、０．１～０．５μｍであることがより好ましい。平面受光素子の表面平均粗さ（Ｒａ）は、０．００１～０．１μｍであることが好ましく、０．００１～０．０５μｍであることがより好ましい。また、シンチレータパネルの表面平均粗さ（Ｒａ）が平面受光素子の表面平均粗さ（Ｒａ）より大きいことが、シンチレータパネルと平面受光素子面の密着性を改良する点から好ましい。 As an embodiment of the present invention, the surface average roughness (Ra) of the scintillator panel is preferably 0.01 to 1.0 μm, and more preferably 0.1 to 0.5 μm. The surface average roughness (Ra) of the planar light receiving element is preferably 0.001 to 0.1 μm, and more preferably 0.001 to 0.05 μm. In addition, it is preferable that the surface average roughness (Ra) of the scintillator panel is larger than the surface average roughness (Ra) of the planar light receiving element from the viewpoint of improving the adhesion between the scintillator panel and the planar light receiving element surface.
　更には、前記シンチレータパネルが、前記平面受光素子に弾力部材により押しつけられ密着している態様であることが好ましい。また、前記シンチレータパネルが、当該シンチレータパネルと前記平面受光素子との間隙の気体の減圧により、当該平面受光素子に密着し、かつ周辺を密着シール部材でシールされている態様であることも好ましい。 Furthermore, it is preferable that the scintillator panel is in close contact with the planar light receiving element by being pressed by an elastic member. Further, it is also preferable that the scintillator panel is in close contact with the planar light receiving element and the periphery thereof is sealed with a tight seal member by reducing the gas in the gap between the scintillator panel and the planar light receiving element.
　本発明においては、当該シンチレータパネルが、可撓性を有していることが好ましい。また、前記密着シール部材が、紫外線硬化型樹脂であることが好ましい。 In the present invention, it is preferable that the scintillator panel has flexibility. Moreover, it is preferable that the said adhesion | attachment sealing member is ultraviolet curable resin.
　更に、当該シンチレータパネルがシンチレータ層を有し、かつ当該シンチレータ層が平面受光素子に直接的に密着している態様であることも好ましい。 Furthermore, it is also preferable that the scintillator panel has a scintillator layer and the scintillator layer is in direct contact with the planar light receiving element.
　本発明においては、前記シンチレータ層が、ヨウ化セシウム（ＣｓＩ）を主成分として含有することが好ましい。また、当該シンチレータ層が、気相堆積法により形成された蛍光体柱状結晶であることが好ましい。 In the present invention, the scintillator layer preferably contains cesium iodide (CsI) as a main component. The scintillator layer is preferably a phosphor columnar crystal formed by a vapor deposition method.
　本発明の放射線画像変換パネルは、可搬性容器に配置し、Ｘ線を曝射し、放射線画像の読み取りを行う態様のＸ線撮影システムに好適に用いることができる。 The radiographic image conversion panel of the present invention can be suitably used in an X-ray imaging system in which an X-ray is exposed by X-rays being placed in a portable container.
　以下、本発明とその構成要素、及び本発明を実施するための最良の形態等について詳細な説明をする。 Hereinafter, the present invention, its components, and the best mode for carrying out the present invention will be described in detail.
　〔シンチレータパネル〕
　本発明の放射線画像変換パネルは、シンチレータパネルと平面受光素子を備えた態様の放射線画像変換パネルであることが好ましい。この場合、シンチレータパネルは、基板上にシンチレータ層を有するシンチレータパネル（「シンチレータプレート」ともいう。）であって、かつ当該基板上に反射層、反射層保護膜（「下引層」ともいう。）、及びシンチレータ層をこの順に設けて成る態様であることが好ましい。 [Scintillator panel]
The radiation image conversion panel of the present invention is preferably a radiation image conversion panel having a scintillator panel and a planar light receiving element. In this case, the scintillator panel is a scintillator panel (also referred to as “scintillator plate”) having a scintillator layer on the substrate, and is also referred to as a reflective layer and a reflective layer protective film (“undercoat layer”) on the substrate. ) And a scintillator layer are preferably provided in this order.
　なお、本発明においては、後述するように、シンチレータ層上に保護層を設ける場合も、設けない場合も、シンチレータ層上の表面平均粗さ（Ｒａ）が０．０１～３．０μｍであることを要する。従って、このため、気相堆積（蒸着）法による蛍光体柱状結晶の形成工程において、蒸着密度、蒸着温度等の制御により当該要件を満たすように調整することが必要となる。 In the present invention, as will be described later, the surface average roughness (Ra) on the scintillator layer is 0.01 to 3.0 μm whether or not a protective layer is provided on the scintillator layer. Cost. Therefore, in the phosphor columnar crystal forming step by the vapor deposition (vapor deposition) method, it is necessary to make adjustments so as to satisfy the requirements by controlling the vapor deposition density, the vapor deposition temperature, and the like.
　本発明でいう「表面平均粗さ」とは、中心線平均表面粗さ（Ｒａ）であり、ＪＩＳ　Ｂ　０６０１：２００１に準拠する。用いることのできる測定装置としては、例えば、東京精密（株）製サーフコム１４００Ｄ等を挙げることができる。本発明の実施においては、カットオフ値を０．８ｍｍにて評価した。 The “surface average roughness” as used in the present invention is the centerline average surface roughness (Ra) and conforms to JIS B 0601: 2001. Examples of the measuring device that can be used include Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd. In the practice of the present invention, the cutoff value was evaluated at 0.8 mm.
　本発明に係るシンチレータパネルは、可撓性を有していることが好ましい。ここで、「可撓性を有している」とは、１２０℃での弾性率（Ｅ１２０）が１０００～６０００Ｎ／ｍｍ２であることをいう。なお、「弾性率」とは、引張試験機を用い、ＪＩＳ　Ｃ　２３１８に準拠したサンプルの標線が示すひずみと、それに対応する応力が直線的な関係を示す領域において、ひずみ量に対する応力の傾きを求めたものである。これがヤング率と呼ばれる値であり、本発明では、かかるヤング率を弾性率と定義する。 The scintillator panel according to the present invention preferably has flexibility. Here, “having flexibility” means that the elastic modulus (E120) at 120 ° C. is 1000 to 6000 N / mm 2 . Note that the “elastic modulus” refers to the slope of the stress with respect to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS C 2318 and the corresponding stress have a linear relationship using a tensile tester. Is what we asked for. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.
　上記可撓性の要件を満たすための主な手段としては、後述するように可撓性を有する基板を用いることが好ましい。 As a main means for satisfying the above flexibility requirement, it is preferable to use a flexible substrate as will be described later.
　〔シンチレータ層〕
　本発明に係るシンチレータ層（「蛍光体層」ともいう。）を構成する蛍光体を形成する材料としては、種々の公知の蛍光体材料を使用することができるが、Ｘ線から可視光に対する変更率が比較的高く、蒸着によって容易に蛍光体を柱状結晶構造に形成できるため、光ガイド効果により結晶内での発光光の散乱が抑えられ、シンチレータ層の厚さを厚くすることが可能であることから、ヨウ化セシウム（ＣｓＩ）が好ましい。 [Scintillator layer]
As a material for forming the phosphor constituting the scintillator layer (also referred to as “phosphor layer”) according to the present invention, various known phosphor materials can be used, but changes from X-ray to visible light can be used. Since the rate is relatively high and the phosphor can be easily formed into a columnar crystal structure by vapor deposition, scattering of the emitted light within the crystal can be suppressed by the light guide effect, and the thickness of the scintillator layer can be increased. Therefore, cesium iodide (CsI) is preferable.
　但し、ＣｓＩのみでは発光効率が低いために、各種の賦活剤が添加される。例えば、特公昭５４－３５０６０号公報の如く、ＣｓＩとヨウ化ナトリウム（ＮａＩ）を任意のモル比で混合したものが挙げられる。また、例えば特開２００１－５９８９９号公報に開示されているようなＣｓＩを蒸着で、タリウム（Ｔｌ）、ユウロピウム（Ｅｕ）、インジウム（Ｉｎ）、リチウム（Ｌｉ）、カリウム（Ｋ）、ルビジウム（Ｒｂ）、ナトリウム（Ｎａ）などの賦活物質を含有するＣｓＩが好ましい。本発明においては、特に、タリウム（Ｔｌ）、ユウロピウム（Ｅｕ）が好ましい。更に、タリウム（Ｔｌ）が好ましい。 However, since CsI alone has low luminous efficiency, various activators are added. For example, as disclosed in Japanese Examined Patent Publication No. 54-35060, a mixture of CsI and sodium iodide (NaI) in an arbitrary molar ratio can be mentioned. Further, for example, CsI as disclosed in Japanese Patent Application Laid-Open No. 2001-59899 is deposited, and thallium (Tl), europium (Eu), indium (In), lithium (Li), potassium (K), rubidium (Rb) ), CsI containing an activating substance such as sodium (Na) is preferred. In the present invention, thallium (Tl) and europium (Eu) are particularly preferable. Furthermore, thallium (Tl) is preferred.
　なお、本発明においては、特に、１種類以上のタリウム化合物を含む添加剤とヨウ化セシウムとを原材料とすることが好ましい。すなわち、タリウム賦活ヨウ化セシウム（ＣｓＩ：Ｔｌ）は４００ｎｍから７５０ｎｍまでの広い発光波長をもつことから好ましい。 In the present invention, it is particularly preferable to use an additive containing one or more types of thallium compounds and cesium iodide as raw materials. That is, thallium activated cesium iodide (CsI: Tl) is preferable because it has a wide emission wavelength from 400 nm to 750 nm.
　本発明に係る１種類以上のタリウム化合物を含有する添加剤のタリウム化合物としては、種々のタリウム化合物（＋Ｉと＋IIIの酸化数の化合物）を使用することができる。 As the thallium compound as an additive containing one or more types of thallium compounds according to the present invention, various thallium compounds (compounds having oxidation numbers of + I and + III) can be used.
　本発明において、好ましいタリウム化合物は、臭化タリウム（ＴｌＢｒ）、塩化タリウム（ＴｌＣｌ）、又はフッ化タリウム（ＴｌＦ，ＴｌＦ３）等である。 In the present invention, a preferred thallium compound is thallium bromide (TlBr), thallium chloride (TlCl), thallium fluoride (TlF, TlF 3 ), or the like.
　また、本発明に係るタリウム化合物の融点は、４００～７００℃の範囲内にあることが好ましい。７００℃以内を超えると、柱状結晶内での添加剤が不均一に存在してしまい、発光効率が低下する。なお、本発明での融点とは、常温常圧下における融点である。 The melting point of the thallium compound according to the present invention is preferably in the range of 400 to 700 ° C. If the temperature exceeds 700 ° C., the additives in the columnar crystals exist non-uniformly, resulting in a decrease in luminous efficiency. In the present invention, the melting point is a melting point at normal temperature and pressure.
　また、タリウム化合物の分子量は２０６～３００の範囲内にあることが好ましい。 The molecular weight of the thallium compound is preferably in the range of 206 to 300.
　本発明のシンチレータ層において、当該添加剤の含有量は目的性能等に応じて、最適量にすることが望ましいが、ヨウ化セシウムの含有量に対して、０．００１～５０ｍｏｌ％、更に０．１～１０．０ｍｏｌ％であることが好ましい。 In the scintillator layer of the present invention, the content of the additive is desirably an optimum amount according to the target performance and the like, but is 0.001 to 50 mol%, and further preferably 0.000 to the content of cesium iodide. It is preferably 1 to 10.0 mol%.
　ここで、ヨウ化セシウムに対し、添加剤が０．００１ｍｏｌ％以上であると、ヨウ化セシウム単独使用で得られる発光輝度の向上がみられ、目的とする発光輝度を得る点で好ましい。また、５０ｍｏｌ％以下であるとヨウ化セシウムの性質・機能を保持することができて好ましい。 Here, when the additive is 0.001 mol% or more with respect to cesium iodide, the emission luminance obtained by using cesium iodide alone is improved, which is preferable in terms of obtaining the target emission luminance. Moreover, it is preferable that it is 50 mol% or less because the properties and functions of cesium iodide can be maintained.
　なお、本発明においては、基板上、例えば、高分子フィルム上にシンチレータの原料の蒸着によりシンチレータ層をした後に、該高分子フィルムのガラス転移温度を基準として－５０℃～＋２０℃の温度範囲の雰囲気下で１時間以上の熱処理することを要する。これにより、フィルムの変形や蛍光体の剥がれの発生がなく、発光効率の高いシンチレータパネルを実現することができる。 In the present invention, after a scintillator layer is deposited on a substrate, for example, a polymer film by vapor deposition of the raw material of the scintillator, the temperature range of −50 ° C. to + 20 ° C. is based on the glass transition temperature of the polymer film. It requires heat treatment for 1 hour or more in an atmosphere. Thereby, the deformation | transformation of a film and generation | occurrence | production of peeling of a fluorescent substance do not occur, and a scintillator panel with high luminous efficiency is realizable.
　以上の説明から分かるように、本発明に係るシンチレータ層は、ヨウ化セシウムを含有する柱状蛍光体層であることが好ましく、かつ気相成長法により形成されたことが好ましい。気相成長法としては、従来公知の、真空蒸着法、スパッタリング法、ＣＶＤ法などを用いることができる。 As can be seen from the above description, the scintillator layer according to the present invention is preferably a columnar phosphor layer containing cesium iodide, and is preferably formed by a vapor phase growth method. As the vapor phase growth method, a conventionally known vacuum deposition method, sputtering method, CVD method or the like can be used.
　なお、シンチレータ層（蛍光体層）の厚さは、１００～８００μｍであることが好ましく、１２０～７００μｍであることが、輝度と鮮鋭性の特性をバランスよく得られる点からより好ましい。 The thickness of the scintillator layer (phosphor layer) is preferably 100 to 800 μm, and more preferably 120 to 700 μm from the viewpoint of obtaining a good balance between luminance and sharpness characteristics.
　（保護層）
　本発明に係る保護層は、シンチレータ層の保護を主眼とするものである。すなわち、ヨウ化セシウム（ＣｓＩ）は、吸湿性が高く露出したままにしておくと空気中の水蒸気を吸湿して潮解してしまうため、これを防止することを主眼とする。当該保護層は、種々の材料を用いて形成することができる。 (Protective layer)
The protective layer according to the present invention focuses on protecting the scintillator layer. That is, cesium iodide (CsI) absorbs water vapor in the air and deliquesces when exposed to a high hygroscopic property, and therefore the main purpose is to prevent this. The protective layer can be formed using various materials.
　本発明に係るシンチレータパネルにおいては、当該保護層として、先ず、シンチレータプレートのシンチレータ層上に保護フィルムを設けることができる。 In the scintillator panel according to the present invention, as the protective layer, first, a protective film can be provided on the scintillator layer of the scintillator plate.
　更に、上記シンチレータ層の側に配置した第１保護フィルムと、基板の外側に配置した第２保護フィルムとにより当該シンチレータパネが封止され、かつ当該第１保護フィルムは当該シンチレータ層に物理化学的に接着されていない態様とすることが好ましい。 Further, the scintillator panel is sealed by a first protective film disposed on the scintillator layer side and a second protective film disposed on the outside of the substrate, and the first protective film is physicochemically bonded to the scintillator layer. It is preferable to set it as the aspect which is not adhere | attached on.
　ここで、「物理化学的に接着されていない」とは、前述のように、接着剤を用いて物理的相互作用又は化学反応等によって接着されていないことをいう。この接着されていない状態は、微視的にはシンチレータ層面と保護フィルムは点接触してはいたとしても、光学的、力学的にはほとんどシンチレータ層面と保護フィルムは不連続体として扱える状態のことといえるものである。 Here, “not physically bonded” means that it is not bonded by physical interaction or chemical reaction using an adhesive as described above. This non-bonded state is a state in which the scintillator layer surface and the protective film can be treated as a discontinuous optically and mechanically even though the scintillator layer surface and the protective film are point contacted microscopically. It can be said.
　なお、保護層をシンチレータ層上設ける場合、当該保護層の表面平均粗さ（Ｒａ）が０．０１～３．０μｍであることを要する。従って、この要件を満たす保護フィルムの選択又は形成条件の採用が必要となる。なお保護層の表面平均粗さ（Ｒａ）０．０１～１．０μｍであることが好ましく、０．１～０．５μｍであることがより好ましい。 When the protective layer is provided on the scintillator layer, it is necessary that the average surface roughness (Ra) of the protective layer is 0.01 to 3.0 μm. Therefore, it is necessary to select a protective film that satisfies this requirement or to adopt formation conditions. The average surface roughness (Ra) of the protective layer is preferably 0.01 to 1.0 μm, and more preferably 0.1 to 0.5 μm.
　次に本発明において使用する保護フィルムについて詳細な説明をする。 Next, the protective film used in the present invention will be described in detail.
　本発明に使用する保護フィルムの構成例としては、保護層（最外層）／中間層（防湿性層）／最内層（熱溶着層）の構成を有した多層積層材料が挙げられる。又、更に各層は必要に応じて多層とすることも可能である。 Examples of the configuration of the protective film used in the present invention include a multilayer laminated material having a configuration of a protective layer (outermost layer) / intermediate layer (moisture-proof layer) / innermost layer (thermal welding layer). Furthermore, each layer can be a multilayer as required.
　〈最内層（熱溶着層）〉
　最内層の熱可塑性樹脂フィルムとしてはＥＶＡ、ＰＰ、ＬＤＰＥ、ＬＬＤＰＥ及びメタロセン触媒を使用して製造したＬＤＰＥ、ＬＬＤＰＥ、又、これらフィルムとＨＤＰＥフィルムの混合使用したフィルムを使用することが好ましい。 <Innermost layer (thermal welding layer)>
As the innermost thermoplastic resin film, it is preferable to use EVA, PP, LDPE, LLDPE and LDPE, LLDPE produced by using a metallocene catalyst, or a film using a mixture of these films and HDPE films.
　〈中間層（防湿性層）〉
　中間層（防湿性層）としては、特開平６－９５３０２号及び真空ハンドブック増訂版ｐ１３２～ｐ１３４（ＵＬＶＡＣ　日本真空技術Ｋ．Ｋ）に記載されている如き、無機膜を少なくとも一層有する層が挙げられる。無機膜としては金属蒸着膜及び無機酸化物の蒸着膜が挙げられる。 <Intermediate layer (moisture-proof layer)>
Examples of the intermediate layer (moisture-proof layer) include layers having at least one inorganic film as described in JP-A-6-95302 and the vacuum handbook revised editions p132 to p134 (ULVAC Japan Vacuum Technology KK). It is done. Examples of the inorganic film include a metal vapor-deposited film and an inorganic oxide vapor-deposited film.
　金属蒸着膜としては、例えばＺｒＮ、ＳｉＣ、ＴｉＣ、Ｓｉ３Ｎ４、単結晶Ｓｉ、ＺｒＮ、ＰＳＧ、アモルファスＳｉ、Ｗ、アルミニウム等が挙げられ、特に好ましい金属蒸着膜としては、例えばアルミニウムが挙げられる。 Examples of the metal vapor deposition film include ZrN, SiC, TiC, Si 3 N 4 , single crystal Si, ZrN, PSG, amorphous Si, W, aluminum, and the like, and a particularly preferable metal vapor deposition film includes, for example, aluminum. .
　無機物蒸着膜としては薄膜ハンドブックｐ８７９～ｐ９０１（日本学術振興会）、真空技術ハンドブックｐ５０２～ｐ５０９、ｐ６１２、ｐ８１０（日刊工業新聞社）、真空ハンドブック増訂版ｐ１３２～ｐ１３４（ＵＬＶＡＣ　日本真空技術Ｋ．Ｋ）に記載されている如き無機物蒸着膜が挙げられる。これらの無機物蒸着膜としては、例えば、Ｃｒ２Ｏ３、ＳｉｘＯｙ（ｘ＝１、ｙ＝１．５～２．０）、Ｔａ２Ｏ３、ＺｒＮ、ＳｉＣ、ＴｉＣ、ＰＳＧ、Ｓｉ３Ｎ４、単結晶Ｓｉ、アモルファスＳｉ、Ｗ、ＡＩ２Ｏ３等が用いられる。 Thin film handbooks p879-p901 (Japan Society for the Promotion of Science), vacuum technology handbooks p502-p509, p612, p810 (Nikkan Kogyo Shimbun), vacuum handbook revised editions p132-p134 (ULVAC Japan Vacuum Technology KK) Inorganic vapor-deposited films as described in (1). As these inorganic vapor deposition films, for example, Cr 2 O 3 , Si x O y (x = 1, y = 1.5 to 2.0), Ta 2 O 3 , ZrN, SiC, TiC, PSG, Si 3 N 4 , single crystal Si, amorphous Si, W, AI 2 O 3 or the like is used.
　中間層（防湿性層）の基材として使用する熱可塑性樹脂フィルムとしてはエチレンテトラフルオロエチル共重合体（ＥＴＦＥ）、高密度ポリエチレン（ＨＤＰＥ）、延伸ポリプロピレン（ＯＰＰ）、ポリスチレン（ＰＳ）、ポリメチルメタクリレート（ＰＭＭＡ）、２軸延伸ナイロン６、ポリエチレンテレフタレート（ＰＥＴ）、ポリカーボネート（ＰＣ）、ポリイミド、ポリエーテルスチレン（ＰＥＳ）など一般の包装用フィルムに使用されているフィルム材料を使用することが出来る。 The thermoplastic resin film used as the base material of the intermediate layer (moisture-proof layer) is ethylene tetrafluoroethyl copolymer (ETFE), high-density polyethylene (HDPE), expanded polypropylene (OPP), polystyrene (PS), polymethyl Film materials used for general packaging films such as methacrylate (PMMA), biaxially stretched nylon 6, polyethylene terephthalate (PET), polycarbonate (PC), polyimide, polyether styrene (PES) can be used.
　蒸着膜を作る方法としては真空技術ハンドブック及び包装技術Ｖｏｌ２９－Ｎｏ．８に記載されている如き一般的な方法、例えば抵抗又は高周波誘導加熱法、エレクトロビーム（ＥＢ）法、プラズマ（ＰＣＶＤ）等により作ることが出来る。蒸着膜の厚さとしては４０～２００ｎｍの範囲が好ましく、より好ましくは５０～１８０ｎｍの範囲である。 As a method for forming a deposited film, vacuum technology handbook and packaging technology Vol 29-No. 8, for example, by resistance or high frequency induction heating method, electrobeam (EB) method, plasma (PCVD) or the like. The thickness of the deposited film is preferably in the range of 40 to 200 nm, more preferably in the range of 50 to 180 nm.
　〈最外層〉
　蒸着フィルムシートを介して用いられる熱可塑性樹脂フィルムとしては一般の包装材料として使用されている高分子フィルム（例えば機能性包装材料の新展開株式会社東レリサーチセンター記載の高分子フィルム）である低密度ポリエチレン（ＬＤＰＥ）、ＨＤＰＥ、線状低密度ポリエチレン（ＬＬＤＰＥ）、中密度ポリエチレン、未延伸ポリプロピレン（ＣＰＰ）、ＯＰＰ、延伸ナイロン（ＯＮｙ）、ＰＥＴ、セロハン、ポリビニルアルコール（ＰＶＡ）、延伸ビニロン（ＯＶ）、エチレン－酢酸ビニル共重合体（ＥＶＯＨ）、塩化ビニリデン（ＰＶＤＣ）、フッ素を含むオレフィン（フルオロオレフィン）の重合体又はフッ素を含むオレフィンを共重合体等が使用出来る。 <Outermost layer>
Low density, which is a polymer film used as a general packaging material (for example, a polymer film described in Toray Research Center Co., Ltd., a new development of functional packaging materials) as a thermoplastic resin film used via a vapor-deposited film sheet Polyethylene (LDPE), HDPE, linear low density polyethylene (LLDPE), medium density polyethylene, unstretched polypropylene (CPP), OPP, stretched nylon (ONy), PET, cellophane, polyvinyl alcohol (PVA), stretched vinylon (OV) An ethylene-vinyl acetate copolymer (EVOH), vinylidene chloride (PVDC), a fluorine-containing olefin (fluoroolefin) polymer, a fluorine-containing olefin copolymer, or the like can be used.
　また、これら熱可塑性樹脂フィルムは、必要に応じて異種フィルムと共押し出しで作った多層フィルム、延伸角度を変えて張り合わせて作った多層フィルム等も当然使用出来る。更に必要とする包装材料の物性を得るために使用するフィルムの密度、分子量分布を組み合わせて作ることも当然可能である。最内層の熱可塑性樹脂フィルムとしてはＬＤＰＥ、ＬＬＤＰＥ及びメタロセン触媒を使用して製造したＬＤＰＥ、ＬＬＤＰＥ、又、これらフィルムとＨＤＰＥフィルムの混合使用したフィルムが使用されている。 Of course, as the thermoplastic resin film, a multilayer film made by coextrusion with a different film, a multilayer film made by laminating at different stretching angles, etc. can be used as needed. Furthermore, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties of the packaging material. As the innermost thermoplastic resin film, LDPE, LLDPE produced using LDPE, LLDPE and a metallocene catalyst, or a film using a mixture of these films and HDPE films are used.
　無機物蒸着層を使用しない場合は、保護層に中間層としての機能を持たせる必要がある。この場合、保護層に使用する熱可塑性樹脂フィルムのなかより必要に応じて単体でもよいし又は、２種以上のフィルムを積層させて用いることが出来る。例えばＣＰＰ／ＯＰＰ、ＰＥＴ／ＯＰＰ／ＬＤＰＥ、Ｎｙ／ＯＰＰ／ＬＤＰＥ、ＣＰＰ／ＯＰＰ／ＥＶＯＨ、サランＵＢ／ＬＬＤＰＥ（ここでサランＵＢとは旭化成工業株式会社製の塩化ビニリデン／アクリル酸エステル系共重合樹脂を原料とした２軸延伸フィルムを示す。）Ｋ－ＯＰ／ＰＰ、Ｋ－ＰＥＴ／ＬＬＤＰＥ、Ｋ－Ｎｙ／ＥＶＡ（ここでＫは塩化ビニリデン樹脂をコートしたフィルムを示す）等が使用されている。 When the inorganic deposition layer is not used, it is necessary to provide the protective layer with a function as an intermediate layer. In this case, the thermoplastic resin film used for the protective layer may be a simple substance or may be used by laminating two or more kinds of films as required. For example, CPP / OPP, PET / OPP / LDPE, Ny / OPP / LDPE, CPP / OPP / EVOH, Saran UB / LLDPE (where Saran UB is a vinylidene chloride / acrylic acid ester copolymer resin manufactured by Asahi Kasei Corporation) Bi-axially stretched film made from a material such as K-OP / PP, K-PET / LLDPE, K-Ny / EVA (where K is a film coated with vinylidene chloride resin) or the like is used. .
　これら保護フィルムの製造方法としては、一般的に知られている各種の方法が用いられ、例えばウェットラミネート法、ドライラミネート法、ホットメルトラミネート法、押し出しラミネート法、熱ラミネート法を利用して作ることが可能である。無機物を蒸着したフィルムを使用しない場合も同様な方法が当然使えるがこれらの他に使用材料によっては多層インフレーション方式、共押し出し成形方式により作ることが出来る。 As a method for producing these protective films, various generally known methods are used. For example, a wet laminate method, a dry laminate method, a hot melt laminate method, an extrusion laminate method, and a thermal laminate method are used. Is possible. Of course, the same method can be used in the case where a film on which an inorganic material is deposited is not used, but in addition to these, depending on the material used, it can be formed by a multilayer inflation method or a coextrusion method.
　積層する際に使用される接着剤としては一般的に知られている接着剤が使用可能である。例えば各種ポリエチレン樹脂、各種ポリプロピレン樹脂等のポリオレフィン系熱可塑性樹脂熱溶解接着剤、エチレン－プロピレン共重合体樹脂、エチレン－酢酸ビニル共重合体樹脂、エチレン－エチルアクリレート共重合体樹脂等のエチレン共重合体樹脂、エチレン－アクリル酸共重合体樹脂、アイオノマー樹脂等の熱可塑性樹脂熱溶融接着剤、その他熱溶融型ゴム系接着剤等がある。エマルジョン、ラテックス状の接着剤であるエマルジョン型接着剤の代表例としては、ポリ酢酸ビニル樹脂、酢酸ビニル－エチレン共重合体樹脂、酢酸ビニルとアクリル酸エステル共重合体樹脂、酢酸ビニルとマレイン酸エステル共重合体樹脂、アクリル酸共重合物、エチレン－アクリル酸共重合物等のエマルジョンがある。ラテックス型接着剤の代表例としては、天然ゴム、スチレンブタジエンゴム（ＳＢＲ）、アクリロニトリルブタジエンゴム（ＮＢＲ）、クロロプレンゴム（ＣＲ）等のゴムラテックスがある。又、ドライラミネート用接着剤としてはイソシアネート系接着剤、ウレタン系接着剤、ポリエステル系接着剤等があり、その他、パラフィンワックス、マイクロクリスタリンワックス、エチレン－酢酸ビニル共重合体樹脂、エチレン－エチルアクリレート共重合体樹脂等をブレンドしたホットメルトラミネート接着剤、感圧接着剤、感熱接着剤等公知の接着剤を用いることも出来る。エクストルージョンラミネート用ポリオレフィン系樹脂接着剤はより具体的に言えば、各種ポリエチレン樹脂、ポリプロピレン樹脂、ポリブチレン樹脂などのポリオレフィン樹脂からなる重合物及びエチレン共重合体（ＥＶＡ、ＥＥＡ、等）樹脂の他、Ｌ－ＬＤＰＥ樹脂の如く、エチレンと他のモノマー（α－オレフィン）を共重合させたもの、Ｄｕｐｏｔ社のサーリン、三井ポリケミカル社のハイミラン等のアイオノマー樹脂（イオン共重合体樹脂）及び三井石油化学（株）のアドマー（接着性ポリマー）等がある。その他紫外線硬化型接着剤も最近使われはじめた。特にＬＤＰＥ樹脂とＬ－ＬＤＰＥ樹脂が安価でラミネート適性に優れているので好ましい。又前記記載樹脂を２種以上ブレンドして各樹脂の欠点をカバーした混合樹脂は特に好ましい。例えばＬ－ＬＤＰＥ樹脂とＬＤＰＥ樹脂をブレンドすると延展性が向上し、ネックインが小さくなるのでラミネート速度が向上し、ピンホールが少なくなる。 As the adhesive used when laminating, generally known adhesives can be used. For example, polyolefin thermoplastic resins such as various polyethylene resins, various polypropylene resins, hot melt adhesives, ethylene-propylene copolymer resins, ethylene-vinyl acetate copolymer resins, ethylene copolymer such as ethylene-ethyl acrylate copolymer resins, etc. There are thermoplastic resin hot-melt adhesives such as coalescence resins, ethylene-acrylic acid copolymer resins, ionomer resins, and other hot-melt rubber adhesives. Typical examples of emulsion-type adhesives that are emulsion and latex adhesives are polyvinyl acetate resin, vinyl acetate-ethylene copolymer resin, vinyl acetate and acrylate copolymer resin, vinyl acetate and maleate ester. There are emulsions of copolymer resins, acrylic acid copolymers, ethylene-acrylic acid copolymers, and the like. Typical examples of latex adhesives include rubber latexes such as natural rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), and chloroprene rubber (CR). In addition, adhesives for dry laminating include isocyanate adhesives, urethane adhesives, polyester adhesives, and others, paraffin wax, microcrystalline wax, ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer. Known adhesives such as hot melt laminate adhesives, pressure sensitive adhesives, heat sensitive adhesives and the like blended with polymer resins can also be used. More specifically, the polyolefin resin adhesive for extrusion laminating includes, in addition to various polymers such as polyethylene resins, polypropylene resins, polybutylene resins, and ethylene copolymer (EVA, EEA, etc.) resins, Ionomer resin (ionic copolymer resin) such as L-LDPE resin copolymerized with ethylene and other monomers (α-olefin), Surin from Dupot, Himiran from Mitsui Polychemical, and Mitsui Petrochemical Admer (adhesive polymer), etc. Other UV curable adhesives have recently begun to be used. In particular, LDPE resin and L-LDPE resin are preferred because they are inexpensive and have excellent laminating properties. A mixed resin in which two or more of the above-described resins are blended to cover the defects of each resin is particularly preferable. For example, when L-LDPE resin and LDPE resin are blended, spreadability is improved and neck-in is reduced, so that the lamination speed is improved and pinholes are reduced.
　上記保護フィルムの厚さは、空隙部の形成性、シンチレータ層（蛍光体層）の保護性、鮮鋭性、防湿性、作業性等を考慮し、１２～６０μｍが好ましく、更には２０～４０μｍが好ましい。また、ヘイズ率が、鮮鋭性、放射線画像ムラ、製造安定性、作業性等を考慮し、３％以上４０％以下が好ましく、更には３～１０％が好ましい。ヘイズ率は、日本電色工業株式会社ＮＤＨ　５０００Ｗにより測定した値を示す。必要とするヘイズ率は、市販されている高分子フィルムから適宜選択し、容易に入手することが可能である。 The thickness of the protective film is preferably 12 to 60 μm, more preferably 20 to 40 μm, taking into consideration the formation of voids, the scintillator layer (phosphor layer) protection, sharpness, moisture resistance, workability, and the like. preferable. Further, the haze ratio is preferably 3% or more and 40% or less, more preferably 3 to 10% in consideration of sharpness, radiation image unevenness, manufacturing stability, workability, and the like. A haze rate shows the value measured by Nippon Denshoku Industries Co., Ltd. NDH 5000W. The required haze ratio is appropriately selected from commercially available polymer films and can be easily obtained.
　保護フィルムの光透過率は、光電変換効率、シンチレータ発光波長等を考慮し、５５０ｎｍで７０％以上あることが好ましいが、９９％以上の光透過率のフィルムは工業的に入手が困難であるため実質的に９９％～７０％が好ましい。 The light transmittance of the protective film is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, scintillator emission wavelength, etc., but a film having a light transmittance of 99% or more is difficult to obtain industrially. Substantially 99% to 70% is preferable.
　保護フィルムの透湿度は、シンチレータ層の保護性、潮解性等を考慮し５０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましく、更には１０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましいが、０．０１ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）以下の透湿度のフィルムは工業的に入手が困難であるため実質的に、０．０１ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）以上、５０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましく、更には０．１ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）以上、１０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましい。 The moisture permeability of the protective film is preferably 50 g / m 2 · day (40 ° C., 90% RH) (measured according to JIS Z0208) or less, more preferably 10 g / m in consideration of the scintillator layer protection, deliquescence and the like. 2 · day (40 ° C./90% RH) (measured according to JIS Z0208) or less is preferable, but a film having a water vapor transmission rate of 0.01 g / m 2 · day (40 ° C./90% RH) or less is industrially used. Because it is difficult to obtain, 0.01 g / m 2 · day (40 ° C, 90% RH) or more, 50 g / m 2 · day (40 ° C., 90% RH) (measured according to JIS Z0208) The following is preferable, and more preferably 0.1 g / m 2 · day (40 ° C. · 90% RH) or more and 10 g / m 2 · day (40 ° C. · 90% RH) (measured according to JIS Z0208) or less.
　なお、別の態様の保護層として、シンチレータ及び基板の表面全体に、ＣＶＤ法（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ；「化学蒸着法」ともいう。）により、有機薄膜、例えば、ポリパラキシリレン膜を形成し、保護層とすることができる。 As another protective layer, an organic thin film, for example, a polyparaxylylene film, is formed on the entire surface of the scintillator and the substrate by a CVD method (Chemical Vapor Deposition; also referred to as “chemical vapor deposition method”). It can be a protective layer.
　（反射層）
　本発明に係る反射層は、蛍光体（シンチレータ）から発した光を反射して、光の取り出し効率を高めるためのものである。当該反射層は、Ａｌ，Ａｇ，Ｃｒ，Ｃｕ，Ｎｉ，Ｔｉ，Ｍｇ，Ｒｈ，Ｐｔ及びＡｕからなる元素群の中から選ばれるいずれかの元素を含む材料により形成されることが好ましい。特に、上記の元素からなる金属薄膜、例えば、Ａｇ膜、Ａｌ膜などを用いることが好ましい。また、このような金属薄膜を２層以上形成するようにしても良い。金属薄膜を２層以上とする場合は、下層をＣｒを含む層とすることが基板との接着性を向上させる点から好ましい。また、金属薄膜上にＳｉＯ２、ＴｉＯ２等の金属酸化物からなる層をこの順に設けてさらに反射率を向上させても良い。 (Reflective layer)
The reflective layer according to the present invention is for reflecting light emitted from a phosphor (scintillator) to enhance light extraction efficiency. The reflective layer is preferably formed of a material containing any element selected from the element group consisting of Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au. In particular, it is preferable to use a metal thin film made of the above elements, for example, an Ag film, an Al film, or the like. Two or more such metal thin films may be formed. When the metal thin film has two or more layers, it is preferable that the lower layer is a layer containing Cr from the viewpoint of improving the adhesion to the substrate. Further, a layer made of a metal oxide such as SiO 2 or TiO 2 may be provided in this order on the metal thin film to further improve the reflectance.
　なお、反射層の厚さは、０．０１～０．３μｍであることが、発光光取り出し効率の観点から好ましい。 The thickness of the reflective layer is preferably 0.01 to 0.3 μm from the viewpoint of the emission light extraction efficiency.
　本発明においては、後述するように、基板として、陽極酸化されたアルミニウム等からなる基板を用いることができる。この場合は、陽極酸化皮膜の入射角４５°での可視光の正反射率を６０％以上にしておくことで特別な反射層を設けることなしで光出力が増大する効果が得られる。 In the present invention, as described later, a substrate made of anodized aluminum or the like can be used as the substrate. In this case, the effect of increasing the light output without providing a special reflective layer can be obtained by setting the regular reflectance of visible light at an incident angle of 45 ° of the anodized film to 60% or more.
　（反射層保護膜）
　本発明に係る反射層保護膜（「下引層」ともいう。）は、反射層の保護の観点から、反射層とシンチレータ層の間に設けることが好ましい。 (Reflective layer protective film)
The reflective layer protective film (also referred to as “undercoat layer”) according to the present invention is preferably provided between the reflective layer and the scintillator layer from the viewpoint of protecting the reflective layer.
　また、当該反射層保護膜は、高分子結合材（バインダー）、分散剤等を含有することが好ましい。 The reflective layer protective film preferably contains a polymer binder (binder), a dispersant and the like.
　なお、反射層保護膜の厚さは、０．１～３μｍが好ましい。なお、３μｍ以下であれば、反射層保護膜内での光散乱が小さく鮮鋭性が良好である。更に、反射層保護膜の厚さが２μｍ以下であると熱処理しても柱状結晶性の乱れが発生しない。 In addition, the thickness of the reflective layer protective film is preferably 0.1 to 3 μm. In addition, if it is 3 micrometers or less, the light scattering in a reflection layer protective film will be small, and sharpness will be favorable. Further, when the thickness of the reflective layer protective film is 2 μm or less, the columnar crystallinity is not disturbed even if heat treatment is performed.
　以下、反射層保護膜の構成要素について説明する。 Hereinafter, components of the reflective layer protective film will be described.
　〈高分子結合材〉
　本発明に係る反射層保護膜は、溶剤に溶解又は分散した高分子結合材（以下「バインダー」ともいう。）を塗布、乾燥して形成することが好ましい。高分子結合材としては、具体的には、ポリイミドまたはポリイミド含有樹脂、ポリウレタン、塩化ビニル共重合体、塩化ビニル－酢酸ビニル共重合体、塩化ビニル－塩化ビニリデン共重合体、塩化ビニル－アクリロニトリル共重合体、ブタジエン－アクリロニトリル共重合体、ポリアミド樹脂、ポリビニルブチラール、ポリエステル、セルロース誘導体（ニトロセルロース等）、スチレン－ブタジエン共重合体、各種の合成ゴム系樹脂、フェノール樹脂、エポキシ樹脂、尿素樹脂、メラミン樹脂、フェノキシ樹脂、シリコン樹脂、アクリル系樹脂、尿素ホルムアミド樹脂等が挙げられる。なかでもポリウレタン、ポリエステル、塩化ビニル系共重合体、ポリビニルブチラール、ニトロセルロースを使用することが好ましい。 <Polymer binder>
The reflective layer protective film according to the present invention is preferably formed by applying and drying a polymer binder (hereinafter also referred to as “binder”) dissolved or dispersed in a solvent. Specific examples of the polymer binder include polyimide or polyimide-containing resin, polyurethane, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer. Polymer, butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, polyester, cellulose derivative (nitrocellulose, etc.), styrene-butadiene copolymer, various synthetic rubber resins, phenol resin, epoxy resin, urea resin, melamine resin , Phenoxy resin, silicon resin, acrylic resin, urea formamide resin, and the like. Of these, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, and nitrocellulose are preferably used.
　本発明に係る高分子結合材としては、特にシンチレータ層との密着の点でポリイミドまたはポリイミド含有樹脂、ポリウレタン、ポリエステル、塩化ビニル系共重合体、ポリビニルブチラール、ニトロセルロースなどが好ましい。また、ガラス転位温度（Ｔｇ）が３０～１００℃のポリマーであることが、蒸着結晶と基板との膜付の点で好ましい。この観点からは、特にポリエステル樹脂であることが好ましい。但し、輝度などの画像特性向上のために熱処理温度の向上をはかるとＴｇが３０～１００℃のポリマーでは耐熱性が十分に確保できない場合があり、この際はポリイミドまたはポリイミド含有樹脂を用いる。 As the polymer binder according to the present invention, polyimide or a polyimide-containing resin, polyurethane, polyester, vinyl chloride copolymer, polyvinyl butyral, nitrocellulose and the like are particularly preferable in terms of close contact with the scintillator layer. Further, a polymer having a glass transition temperature (Tg) of 30 to 100 ° C. is preferable in terms of attaching a film between the deposited crystal and the substrate. From this viewpoint, a polyester resin is particularly preferable. However, if the heat treatment temperature is increased to improve image characteristics such as luminance, a polymer having a Tg of 30 to 100 ° C. may not be able to ensure sufficient heat resistance. In this case, polyimide or a polyimide-containing resin is used.
　反射層保護膜の調製に用いることができる溶剤としては、Ｎ，Ｎ－ジメチルアセトアミド、Ｎ－メチル－２－ピロリドン、メタノール、エタノール、ｎ－プロパノール、ｎ－ブタノールなどの低級アルコール、メチレンクロライド、エチレンクロライドなどの塩素原子含有炭化水素、アセトン、メチルエチルケトン、メチルイソブチルケトンなどのケトン、トルエン、ベンゼン、シクロヘキサン、シクロヘキサノン、キシレンなどの芳香族化合物、酢酸メチル、酢酸エチル、酢酸ブチルなどの低級脂肪酸と低級アルコールとのエステル、ジオキサン、エチレングリコールモノエチルエステル、エチレングリコールモノメチルエステルなどのエーテル及びそれらの混合物を挙げることができる。 Solvents that can be used for the preparation of the protective film for the reflective layer include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, lower alcohols such as methanol, ethanol, n-propanol, n-butanol, methylene chloride, ethylene Chlorine-containing hydrocarbons such as chloride, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, aromatic compounds such as toluene, benzene, cyclohexane, cyclohexanone, and xylene, lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, and butyl acetate And ethers such as dioxane, ethylene glycol monoethyl ester, ethylene glycol monomethyl ester, and mixtures thereof.
　なお、本発明に係る反射層保護膜には、シンチレータが発光する光の散乱の防止し、鮮鋭性等を向上させるために顔料や染料を含有させても良い。 The reflective layer protective film according to the present invention may contain a pigment or a dye in order to prevent scattering of light emitted from the scintillator and improve sharpness.
　（基板）
　本発明に係る基板は、各種金属、カーボンやα－カーボン、耐熱性樹脂基板などが使用可能であるが、画像特性・コストなどを鑑みると耐熱性樹脂基板が特に好適である。 (substrate)
As the substrate according to the present invention, various metals, carbon, α-carbon, a heat-resistant resin substrate and the like can be used, but a heat-resistant resin substrate is particularly preferable in view of image characteristics and cost.
　耐熱性樹脂としては、従来公知の樹脂を使用することができるが、いわゆるエンジニアリングプラスチックを用いることが好ましい。ここで、「エンジニアリングプラスチックス」とは、産業用途（工業用途）に使用される高機能のプラスチックスのことであり、一般的に強度や耐熱温度が高く、耐薬品性に優れている等の利点を有する。 Conventionally known resins can be used as the heat resistant resin, but so-called engineering plastics are preferably used. Here, “engineering plastics” are high-performance plastics used in industrial applications (industrial applications), and generally have high strength, heat-resistant temperature, excellent chemical resistance, etc. Have advantages.
　本発明に係るエンジニアリングプラスチックスとしては、特に限定されるものではないが、例えば、ポリサルホン樹脂、ポリエーテルサルホン樹脂、ポリイミド樹脂、ポリエーテルイミド樹脂、ポリアミド樹脂、ポリアセタール樹脂、ポリカーボネート樹脂、ポリエチレンテレフタレート樹脂、ポリブチレンテレフタレート樹脂、芳香族ポリエステル樹脂、変性ポリフェニレンオキサイド樹脂、ポリフェニレンスルフィド樹脂、ポリエーテルケトン樹脂等が好適に用いられる。これらのエンジニアリングプラスチックスは、単独で用いられても良いし、２種類以上が併用されても良い。 The engineering plastics according to the present invention is not particularly limited. For example, polysulfone resin, polyethersulfone resin, polyimide resin, polyetherimide resin, polyamide resin, polyacetal resin, polycarbonate resin, polyethylene terephthalate resin Polybutylene terephthalate resin, aromatic polyester resin, modified polyphenylene oxide resin, polyphenylene sulfide resin, polyether ketone resin and the like are preferably used. These engineering plastics may be used independently and 2 or more types may be used together.
　更に、硬化温度によっては、ポリエーテルエーテルケトン（ＰＥＥＫ）やポリテトラフルオロエチレン（ＰＴＦＥ）等に代表されるスーパーエンジニアリングプラスチックを使用することも好ましい。 Furthermore, depending on the curing temperature, it is also preferable to use a super engineering plastic represented by polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), or the like.
　本発明においては、耐熱性、加工性、機械的強度、及びコスト面で優れた、ポリイミド樹脂又はポリエーテルイミド樹脂のようなポリイミドを含有する樹脂で基板を形成することが好ましい。 In the present invention, the substrate is preferably formed of a resin containing polyimide such as polyimide resin or polyetherimide resin, which is excellent in heat resistance, workability, mechanical strength, and cost.
　なお、本発明に係る基板としては、厚さ５０～５００μｍであること、更に可撓性を有する基板であること、特に樹脂（高分子）フィルムであることが好ましい。 The substrate according to the present invention is preferably a substrate having a thickness of 50 to 500 μm, a flexible substrate, particularly a resin (polymer) film.
　ここで、「可撓性を有する基板」とは、１２０℃での弾性率（Ｅ１２０）が１０００～６０００Ｎ／ｍｍ２である基板をいい、かかる基板としてポリイミド又はポリエチレンナフタレートを含有する高分子フィルムが好ましい。 Here, the “flexible substrate” means a substrate having an elastic modulus (E120) at 120 ° C. of 1000 to 6000 N / mm 2 , and a polymer film containing polyimide or polyethylene naphthalate as the substrate. Is preferred.
　ここで、「弾性率」とは、引張試験機を用い、ＪＩＳ－Ｃ２３１８に準拠したサンプルの標線が示すひずみと、それに対応する応力が直線的な関係を示す領域において、ひずみ量に対する応力の傾きを求めたものである。これがヤング率と呼ばれる値であり、本発明では、かかるヤング率を弾性率と定義する。 Here, the “elastic modulus” refers to the stress relative to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS-C2318 and the corresponding stress have a linear relationship using a tensile tester. The slope is obtained. This is a value called Young's modulus, and in the present invention, this Young's modulus is defined as an elastic modulus.
　本発明に用いられる基板は、上記のように１２０℃での弾性率（Ｅ１２０）が１０００Ｎ／ｍｍ２～６０００Ｎ／ｍｍ２であることが好ましい。より好ましくは１２００Ｎ／ｍｍ２～５０００Ｎ／ｍｍ２である。 Substrate used in the present invention, it is preferable elastic modulus at the 120 ° C. as described above (E120) is 1000N / mm 2 ~ 6000N / mm 2. More preferably, it is 1200 N / mm 2 to 5000 N / mm 2 .
　具体的には、ポリエチレンナフタレート（Ｅ１２０＝４１００Ｎ／ｍｍ２）、ポリエチレンテレフタレート（Ｅ１２０＝１５００Ｎ／ｍｍ２）、ポリブチレンナフタレート（Ｅ１２０＝１６００Ｎ／ｍｍ２）、ポリカーボネート（Ｅ１２０＝１７００Ｎ／ｍｍ２）、シンジオタクチックポリスチレン（Ｅ１２０＝２２００Ｎ／ｍｍ２）、ポリエーテルイミド（Ｅ１２０＝１９００Ｎ／ｍｍ２）、ポリアリレート（Ｅ１２０＝１７００Ｎ／ｍｍ２）、ポリスルホン（Ｅ１２０＝１８００Ｎ／ｍｍ２）、ポリエーテルスルホン（Ｅ１２０＝１７００Ｎ／ｍｍ２）等からなる樹脂（高分子）フィルムが挙げられる。 Specifically, polyethylene naphthalate (E120 = 4100N / mm 2) , polyethylene terephthalate (E120 = 1500N / mm 2) , polybutylene naphthalate (E120 = 1600N / mm 2) , polycarbonate (E120 = 1700N / mm 2) , Syndiotactic polystyrene (E120 = 2200 N / mm 2 ), polyetherimide (E120 = 1900 N / mm 2 ), polyarylate (E120 = 1700 N / mm 2 ), polysulfone (E120 = 1800 N / mm 2 ), polyethersulfone (E120 = 1700N / mm 2) made of such a resin (polymer) film.
　これらは単独で用いてもよく積層あるいは混合して用いてもよい。中でも、特に好ましい樹脂（高分子）フィルムとしては、上述のように、ポリイミド又はポリエチレンナフタレートを含有する樹脂（高分子）フィルムが好ましい。 These may be used singly or may be laminated or mixed. Among them, as a particularly preferable resin (polymer) film, a resin (polymer) film containing polyimide or polyethylene naphthalate is preferable as described above.
　なお、シンチレータパネルと平面受光素子面を貼り合せる際に、基板の変形や蒸着時の反りなどの影響を受け、フラットパネルディテクタの受光面内で均一な画質特性が得られないという点に関して、当該基板を、厚さ５０～５００μｍの樹脂（高分子）フィルムとすることでシンチレータパネルが平面受光素子面形状に合った形状に変形し、放射線画像変換パネルの受光面全体で均一な鮮鋭性が得られる。 In addition, when the scintillator panel and the planar light receiving element surface are bonded, the image quality is not uniform within the light receiving surface of the flat panel detector due to the influence of deformation of the substrate and warpage during vapor deposition. By making the substrate a resin (polymer) film with a thickness of 50 to 500 μm, the scintillator panel is transformed into a shape that matches the shape of the planar light receiving element surface, and uniform sharpness is obtained over the entire light receiving surface of the radiation image conversion panel. It is done.
　本発明においては、アルミニウム等の各種金属からなる基板を用いることができる。例えば、陽極酸化されたアルミニウム等からなる基板を用いることも好ましい。 In the present invention, a substrate made of various metals such as aluminum can be used. For example, it is also preferable to use a substrate made of anodized aluminum or the like.
　陽極酸化されたアルミニウム等からなる基板を作るためには、硫酸、燐酸、シュウ酸、クロム酸又はスルファミド酸、ベンゼンスルホン酸の如き有機酸、又はそれらの混合物を含有する溶液に陽極として浸漬されたアルミニウム板に電流を流す。１～７０質量％の電解質濃度は、０～７０℃の範囲の温度で、より好ましくは３５～６０℃の範囲の温度で使用されることができる。 In order to make a substrate made of anodized aluminum or the like, it was immersed as an anode in a solution containing sulfuric acid, phosphoric acid, oxalic acid, chromic acid or sulfamic acid, an organic acid such as benzenesulfonic acid, or a mixture thereof. Current is passed through the aluminum plate. An electrolyte concentration of 1 to 70% by weight can be used at a temperature in the range of 0 to 70 ° C, more preferably at a temperature in the range of 35 to 60 ° C.
　陽極電流密度は、１～５０Ａ／ｄｍを変化してもよく、また１～１００Ｖの範囲の電圧を変化して１～８ｇ／ｍ２Ａｌ２Ｏ３・Ｈ２Ｏの陽極酸化フィルムを得てもよい。陽極酸化されたアルミニウム板は続いて１０～８０℃の範囲の温度の脱イオン水でリンスされてもよい。 The anode current density, 1 ~ 50A / dm may be changed, also give an anodic oxidation film of 1 ~ 8g / m 2 Al 2 O 3 · H 2 O by changing the voltage in the range of 1 ~ 100 V Also good. The anodized aluminum plate may subsequently be rinsed with deionized water at a temperature in the range of 10-80 ° C.
　陽極酸化工程後、後処理、例えば封止を陽極表面に適用してもよい。陽極酸化によって形成された酸化アルミニウム層の孔の封止はアルミニウム陽極酸化の技術分野で公知の技術である。この技術は例えば“Ｂｅｌｇｉｓｃｈ－Ｎｅｄｅｒｌａｎｄｓ　ｔｉｊｄｓｃｈｒｉｆｔ　ｖｏｏｒ　Ｏｐｐｅｒｖｌａｋｔｅｔｅｃｈｎｉｅｋｅｎ　ｖａｎ　ｍａｔｅｒｉａｌｅｎ”（表面技術及び材料の道程）、Ｖｏｌｕｍｅ２４，１９８０年１月、名称“Ｓｅａｌｉｎｇ－ｋｗａｌｉｔｅｉｔ　ｅｎ　ｓｅａｌｉｎｇ－ｃｏｎｔｒｏｌｅ　ｖａｎ　ｇｅａｎｏｄｉｓｅｅｒｄ　Ａｌｕｍｉｎｕｍ”（陽極酸化されたアルミニウムの封止品質及び封止制御）に記載されている。 After the anodizing step, post-treatment such as sealing may be applied to the anode surface. Sealing the holes in the aluminum oxide layer formed by anodization is a well-known technique in the technical field of aluminum anodization. This technology is, for example, “Belgsch-Nederlands tijdschiff voor Uppervlacktechtechniken van materialen” (surface technology and material process), Volume 24, January 1980, name “Sealing-kalliteminte-alumine-oxidant-alumino-oxidant-alumine-oxidant-alumino-oxidant-alumino-oxidant Sealing quality and sealing control).
　なお、シンチレータパネルと平面受光素子面を貼り合せる場合には、基板の変形や蒸着時の反りなどの影響を受け、放射線画像変換パネル（フラットパネルディテクター）の受光面内で均一な画質特性が得られないという点に関して、当該基板を、厚さ５０μｍ以上５００μｍ以下の樹脂基板とすることでシンチレータパネルが平面受光素子面形状に合った形状に変形し、放射線画像変換パネルの受光面全体で均一な鮮鋭性が得られる。 When the scintillator panel and the planar light-receiving element surface are bonded together, uniform image quality characteristics can be obtained within the light-receiving surface of the radiation image conversion panel (flat panel detector) due to the effects of deformation of the substrate and warpage during vapor deposition. In that case, the substrate is a resin substrate having a thickness of 50 μm or more and 500 μm or less, so that the scintillator panel is deformed into a shape that matches the shape of the planar light receiving element surface, and is uniform over the entire light receiving surface of the radiation image conversion panel. Sharpness is obtained.
　（シンチレータパネルの作製方法等）
　次に、本発明の実施の形態を図１～図４を参照しながら説明するが、本発明はこれに限定されるものではない。 (Scintillator panel manufacturing method, etc.)
Next, embodiments of the present invention will be described with reference to FIGS. 1 to 4, but the present invention is not limited thereto.
　図１はシンチレータパネルの概略平面図である。図１（ａ）はシンチレータプレートを４方シールで保護フィルムにより封止したシンチレータパネルの概略平面図である。図１（ｂ）はシンチレータプレートを２方シールで保護フィルムにより封止したシンチレータパネルの概略平面図である。図１（ｃ）はシンチレータプレートを３方シールで保護フィルムにより封止したシンチレータパネルの概略平面図である。 FIG. 1 is a schematic plan view of a scintillator panel. FIG. 1A is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a four-way seal. FIG. 1B is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a two-way seal. FIG. 1C is a schematic plan view of a scintillator panel in which a scintillator plate is sealed with a protective film with a three-way seal.
　図１（ａ）中、１ａはシンチレータパネルを示す。シンチレータパネル１ａは、シンチレータプレート１０１と、シンチレータプレート１０１のシンチレータ層１０１ｂ（図２を参照）側に配置された第１保護フィルム１０２ａと、シンチレータプレート１０１の基板１０１ａ側に配置された第２保護フィルム１０２ｂ（図２を参照）とを有している。１０３ａ～１０３ｄは保護フィルム１０２ａと第２保護フィルム１０２ｂ（図２を参照）との４箇所の封止部を示し、封止部１０３ａ～１０３ｄはシンチレータプレート１０１の周縁部より何れも外側に形成されている。４方シールとは、本図に示す如く、４方に封止部を有する状態を言う。本図に示される、４方シールの形態は第１保護フィルム１０２ａと第２保護フィルム１０２ｂ（図２を参照）との２枚のプレート状の保護フィルムの間にシンチレータプレートを挟み、４方をシールすることで作製することが出来る。この場合、第１保護フィルム１０２ａと、第２保護フィルム１０２ｂ（図２を参照）とは、異なっていても、同じてあってもよく、必要に応じて適宜選択することが可能である。 In FIG. 1A, 1a indicates a scintillator panel. The scintillator panel 1a includes a scintillator plate 101, a first protective film 102a disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101. 102b (see FIG. 2). Reference numerals 103a to 103d denote four sealing portions of the protective film 102a and the second protective film 102b (see FIG. 2), and the sealing portions 103a to 103d are formed outside the peripheral edge portion of the scintillator plate 101. ing. The four-way seal means a state having sealing portions in four directions as shown in the figure. The four-sided seal shown in this figure has a scintillator plate sandwiched between two plate-like protective films of a first protective film 102a and a second protective film 102b (see FIG. 2). It can be produced by sealing. In this case, the 1st protective film 102a and the 2nd protective film 102b (refer FIG. 2) may differ or may be the same, and can be suitably selected as needed.
　図１（ｂ）中、１ｂはシンチレータパネルを示す。シンチレータパネル１ｂは、シンチレータプレート１０１と、シンチレータプレート１０１のシンチレータ層１０１ｂ（図２を参照）側に配置された第１保護フィルム１０４と、シンチレータプレート１０１の基板１０１ａ側に配置された第２保護フィルム（不図示）とを有している。１０５ａ、１０５ｂは保護フィルム１０４と基板側に配置された第２保護フィルム（不図示）との２箇所の封止部を示し、封止部１０５ａ、１０５ｂはシンチレータプレート１０１の周縁部より何れも外側に形成されている。２方シールとは、本図に示す如く、２方に封止部を有する状態を言う。本図に示される、２方シールの形態はインフレーション方により筒状に成形された保護フィルムの間にシンチレータプレートを挟み、２方をシールすることで作製することが出来る。この場合、第１保護フィルム１０４と第２保護フィルム（不図示）とに使用する使用する保護フィルムは同じものとなる。 In FIG. 1 (b), 1b indicates a scintillator panel. The scintillator panel 1b includes a scintillator plate 101, a first protective film 104 disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101. (Not shown). Reference numerals 105 a and 105 b denote two sealing portions of the protective film 104 and a second protective film (not shown) arranged on the substrate side, and the sealing portions 105 a and 105 b are both outside the peripheral portion of the scintillator plate 101. Is formed. The two-side seal means a state having a sealing portion in two directions as shown in the figure. The two-way seal shown in this figure can be manufactured by sandwiching a scintillator plate between protective films formed into a cylindrical shape by the inflation method and sealing the two sides. In this case, the protective films used for the first protective film 104 and the second protective film (not shown) are the same.
　図１（ｃ）中、１ｃはシンチレータパネルを示す。シンチレータパネル１ｃは、シンチレータプレート１０１と、シンチレータプレート１０１のシンチレータ層１０１ｂ（図２を参照）側に配置された第１保護フィルム１０６と、シンチレータプレート１０１の基板１０１ａ側に配置された第２保護フィルム（不図示）とを有している。１０７ａ～１０７ｃは第１保護フィルム１０６と基板側に配置された第２保護フィルム（不図示）との３箇所の封止部を示し、封止部１０７ａ～１０７ｃはシンチレータプレート１０１の周縁部より何れも外側に形成されている。３方シールとは、本図に示す如く、３方に封止部を有する状態を言う。本図に示される、３方シールの形態は一枚の保護フィルムを中心で折りたたみ、成形された２枚の保護フィルムの間にシンチレータプレートを挟み、３方をシールすることで作製することが出来る。この場合、第１保護フィルム１０６と、第２保護フィルム（不図示）とに使用する保護フィルムは同じものとなる。図１（ａ）～図１（ｃ）に示す様に第１保護フィルムと第２保護フィルムとの２枚の保護フィルムの封止部がシンチレータプレートの周縁部の外側にあるため外周部からの水分進入を阻止することが可能となっている。図１（ａ）～図１（ｃ）に示すシンチレータプレートのシンチレータ層は、後述する気相堆積法で基板の上に形成することが好ましい。気相堆積法としては、蒸着法、スパッタリング法、ＣＶＤ法、イオンプレーティング法等を用いることが可能である。 In FIG. 1 (c), 1c represents a scintillator panel. The scintillator panel 1c includes a scintillator plate 101, a first protective film 106 disposed on the scintillator layer 101b (see FIG. 2) side of the scintillator plate 101, and a second protective film disposed on the substrate 101a side of the scintillator plate 101. (Not shown). Reference numerals 107 a to 107 c denote three sealing portions of the first protective film 106 and a second protective film (not shown) arranged on the substrate side. The sealing portions 107 a to 107 c are arranged from the periphery of the scintillator plate 101. Is also formed on the outside. The three-way seal means a state having a sealing portion in three directions as shown in the figure. The three-sided seal shown in this figure can be manufactured by folding a single protective film around the center and sandwiching the scintillator plate between the two protective films that have been molded. . In this case, the protective films used for the first protective film 106 and the second protective film (not shown) are the same. As shown in FIG. 1 (a) to FIG. 1 (c), the sealing portion of the two protective films of the first protective film and the second protective film is outside the peripheral portion of the scintillator plate. It is possible to prevent moisture from entering. The scintillator layer of the scintillator plate shown in FIGS. 1 (a) to 1 (c) is preferably formed on the substrate by a vapor deposition method to be described later. As the vapor deposition method, an evaporation method, a sputtering method, a CVD method, an ion plating method, or the like can be used.
　図１（ａ）～図１（ｃ）に示すシンチレータパネルの形態は、シンチレータプレートのシンチレータ層の種類、製造装置等により選択することが可能である。 The form of the scintillator panel shown in FIGS. 1 (a) to 1 (c) can be selected depending on the type of scintillator layer of the scintillator plate, the manufacturing apparatus, and the like.
　図２は、図１（ａ）のＡ－Ａ′に沿った概略断面及び平面受光素子と接触状態を示した図である。図２（ａ）は、図１（ａ）のＡ－Ａ′に沿った概略拡大断面及び平面受光素子と接触状態を示した図である。図２（ｂ）は、図２（ａ）のＰで示される部分の概略拡大図である。 FIG. 2 is a schematic cross-sectional view taken along the line AA ′ in FIG. 1A and shows a contact state with the planar light receiving element. FIG. 2A is a diagram showing a schematic enlarged cross-section along AA ′ in FIG. 1A and a contact state with the planar light receiving element. FIG. 2B is a schematic enlarged view of a portion indicated by P in FIG.
　シンチレータプレート１０１は基板１０１ａと、基板１０１ａの上に形成されたシンチレータ層１０１ｂとを有している。１０２ｂはシンチレータプレート１０１の基板１０１ａ側に配置された第２保護フィルムを示す。１０８は第１保護フィルム１０２ａとシンチレータ層１０１ｂとの間で部分的に接触している点接触部分Ｅ～Ｉの間に形成された空隙部（空気層）を示す。空隙部（空気層）１０８は空気層となっており、空隙部（空気層）１０８の屈折率と第１保護フィルム１０２ａの屈折率との関係は、保護フィルム１０２ａの屈折率＞＞空隙部（空気層）１０８の屈折率となっている。 The scintillator plate 101 has a substrate 101a and a scintillator layer 101b formed on the substrate 101a. Reference numeral 102b denotes a second protective film disposed on the substrate 101a side of the scintillator plate 101. Reference numeral 108 denotes a gap (air layer) formed between the point contact portions E to I that are in partial contact between the first protective film 102a and the scintillator layer 101b. The void portion (air layer) 108 is an air layer, and the relationship between the refractive index of the void portion (air layer) 108 and the refractive index of the first protective film 102a is the refractive index of the protective film 102a >> Air layer) 108 has a refractive index.
　また１０９は第１保護フィルム１０２ａと平面受光素子２０１との間で部分的に接触している点接触部分Ｊ～Ｏの間に形成された空隙部（空気層）を示す。空隙部（空気層）１０９は空気層となっており、空隙部（空気層）１０９の屈折率と第１保護フィルム１０２ａの屈折率との関係は、保護フィルム１０２ａの屈折率＞＞空隙部（空気層）１０９の屈折率となっている。 Reference numeral 109 denotes a gap (air layer) formed between the point contact portions J to O that are in partial contact between the first protective film 102a and the planar light receiving element 201. The void portion (air layer) 109 is an air layer, and the relationship between the refractive index of the void portion (air layer) 109 and the refractive index of the first protective film 102a is the refractive index of the protective film 102a >> Air layer) 109 has a refractive index.
　尚、図１（ｂ）、図１（ｃ）に示されるシンチレータパネルの場合、空隙部（空気層）１０８及び１０９の屈折率と第１保護フィルム１０２ａの屈折率との関係は、本図の場合と同じである。 In the case of the scintillator panels shown in FIGS. 1B and 1C, the relationship between the refractive index of the gaps (air layers) 108 and 109 and the refractive index of the first protective film 102a is shown in FIG. Same as the case.
　即ち、シンチレータ層１０１ｂ側に配置された第１保護フィルム１０２ａはシンチレータ層１０１ｂと全面密着の状態とはなっていなく、点接触部分Ｅ～Ｉで部分的に接触している状態となっている。シンチレータ層１０１ｂ側に配置された第１保護フィルム１０２ａでシンチレータ層１０１ｂ側全面を覆うとき、この点接触部分Ｅ～Ｈの箇所がシンチレータ層１０１ｂの表面積に対して０．１箇所／ｍｍ２以上、２５箇所／ｍｍ２以下とすることが好ましい。本発明では、この様な状態をシンチレータ層側に配置された第１保護フィルムは実質的に接着していない状態と言う。尚、図１（ｂ）、図１（ｃ）に示されるシンチレータパネルの場合も、点接触部分の箇所の数とシンチレータ層の表面積に対する関係は本図の場合と同じである。 In other words, the first protective film 102a arranged on the scintillator layer 101b side is not in close contact with the scintillator layer 101b, but is in partial contact with the point contact portions E to I. When the entire surface of the scintillator layer 101b is covered with the first protective film 102a disposed on the scintillator layer 101b side, the point contact portions E to H are 0.1 sites / mm 2 or more with respect to the surface area of the scintillator layer 101b. It is preferable to be 25 locations / mm 2 or less. In the present invention, such a state is referred to as a state in which the first protective film disposed on the scintillator layer side is not substantially adhered. In the case of the scintillator panels shown in FIGS. 1B and 1C, the relationship between the number of point contact portions and the surface area of the scintillator layer is the same as that in this figure.
　また第１保護フィルム１０２ａは平面受光素子２０１と全面密着の状態とはなっておらず、点接触部分Ｊ～Ｏで部分的に接触している状態となっている。この点接触部分Ｊ～Ｏの箇所が平面受光素子２０１の表面積に対して０．１箇所／ｍｍ２以上、２５箇所／ｍｍ２以下とすることが好ましい。 Further, the first protective film 102a is not in a state of close contact with the planar light receiving element 201 but is in partial contact with the point contact portions J to O. The point contact portions J to O are preferably set at 0.1 place / mm 2 or more and 25 places / mm 2 or less with respect to the surface area of the planar light receiving element 201.
　第１保護フィルム１０２ａとシンチレータ層１０１ｂの点接触部分の数、及び第１保護フィルム１０２ａと平面受光素子２０１の点接触部分の数がそれぞれ２５箇所／ｍｍ２を超える場合は、鮮鋭性が劣化する原因の一つになっている。点接触部分の数が０．１箇所／ｍｍ２箇所未満の場合も、輝度や鮮鋭性が劣化する原因の一つになっている。 Sharpness deteriorates when the number of point contact portions between the first protective film 102a and the scintillator layer 101b and the number of point contact portions between the first protective film 102a and the planar light receiving element 201 exceed 25 locations / mm 2 , respectively. It is one of the causes. Even when the number of point contact portions is less than 0.1 / mm 2 , this is one of the causes of deterioration in luminance and sharpness.
　点接触部分の数の測定は、次の方法により行うことが可能である。 Measure the number of point contact parts by the following method.
　シンチレータパネルに対し、Ｘ線を照射し発光をＣＭＯＳやＣＣＤを使用した平面受光素子で読み取り、信号値のデータを得る。このデータをフーリエ変換することより、空間周波数ごとのパワースペクトルデータを得る。このパワースペクトルのピークの位置より点接触部分の数を知ることができる。つまり保護層が接触している点部分と非接触の部分では微細な輝度差が発生し、この周期を測定することで接触点数を知ることが出来る。 The X-ray is irradiated to the scintillator panel and the emitted light is read by a flat light receiving element using a CMOS or CCD to obtain signal value data. Power spectrum data for each spatial frequency is obtained by Fourier transforming this data. The number of point contact portions can be known from the position of the peak of the power spectrum. That is, a minute luminance difference occurs between the point portion where the protective layer is in contact and the non-contact portion, and the number of contact points can be known by measuring this period.
　但しこの方法では第１保護フィルム１０２ａとシンチレータ層１０１ｂの点接触部分の数、及び第１保護フィルム１０２ａと平面受光素子２０１の点接触部分の数の総和が検出されるため、それぞれの点接触数を分離するためには、例えば、第１保護フィルム１０２ａとシンチレータ層１０１ｂを接着剤により完全密着し、第１保護フィルム１０２ａと平面受光素子２０１の点接触部分の接触点数のみを測定する方法がある。 However, in this method, the total number of point contact portions between the first protective film 102a and the scintillator layer 101b and the number of point contact portions between the first protective film 102a and the planar light receiving element 201 is detected. For example, there is a method in which the first protective film 102a and the scintillator layer 101b are completely adhered by an adhesive, and only the number of contact points of the point contact portion between the first protective film 102a and the planar light receiving element 201 is measured. .
　本図に示す様に、シンチレータパネル１ａはシンチレータプレート１０１のシンチレータ層１０１ｂ側に配置された第１保護フィルム１０２ａと、基板１０１ａ側に配置された第２保護フィルム１０２ｂとで基板１０１ａ及びシンチレータ層１０１ｂの全面が第１保護フィルム１０２ａで実質的に接着していない状態で覆われ、第１保護フィルム１０２ａと第２保護フィルム１０２ｂの４辺の各端部を封止した形態となっている。 As shown in the figure, the scintillator panel 1a includes a substrate 101a and a scintillator layer 101b, which are a first protective film 102a disposed on the scintillator layer 101b side of the scintillator plate 101 and a second protective film 102b disposed on the substrate 101a side. Is covered with the first protective film 102a in a substantially non-adhered state, and each end of the four sides of the first protective film 102a and the second protective film 102b is sealed.
　シンチレータ層１０１ｂの全面が第１保護フィルム１０２ａで実質的に接着していない状態で覆う方法として次の方法が挙げられる。 As a method of covering the entire surface of the scintillator layer 101b with the first protective film 102a substantially not adhered, the following method may be mentioned.
　１）第１保護フィルムのシンチレータ層と接触する表面の表面粗さを、第１保護フィルムとの密着性、鮮鋭性、平面受光素子との密着性等を考慮し、Ｒａで０．０５～０．８μｍとする。第１保護フィルムの表面形状は、使用する樹脂フィルムを選択することや樹脂フィルム表面に無機物等を含んだ塗膜を塗設することで容易に調整することが可能である。尚、表面粗さＲａは、東京精密社製サーフコム１４００Ｄにより測定した値を示す。 1) The surface roughness of the surface of the first protective film that comes into contact with the scintillator layer is set to 0.05 to 0 in terms of Ra in consideration of adhesion to the first protective film, sharpness, adhesion to a flat light receiving element, and the like. .8 μm. The surface shape of the first protective film can be easily adjusted by selecting a resin film to be used or coating a coating film containing an inorganic substance on the surface of the resin film. In addition, surface roughness Ra shows the value measured by Tokyo Seimitsu Co., Ltd. Surfcom 1400D.
　２）シンチレータプレートを第１保護フィルムと、第２保護フィルムとにより封止するとき、５Ｐａ～８０００Ｐａの減圧条件で行う。この場合、高真空側で封止すると保護フィルムとシンチレータ層の点接触部分の数は増加し、逆に低真空側で封止すると点接触部分の数は減少する。又圧力が８０００Ｐａ以上になると保護フィルム表面にシワが発生し易くなり現実的ではない。 2) When the scintillator plate is sealed with the first protective film and the second protective film, it is performed under a reduced pressure condition of 5 Pa to 8000 Pa. In this case, the number of point contact portions between the protective film and the scintillator layer increases when sealed on the high vacuum side, whereas the number of point contact portions decreases when sealed on the low vacuum side. On the other hand, when the pressure is 8000 Pa or more, wrinkles are easily generated on the surface of the protective film, which is not realistic.
　上記の１）～２）の方法を単独又は組み合わせることで、シンチレータ層１０１ｂの全面が第１保護フィルム１０２ａで実質的に接着していない状態で覆うことが可能となる。 It is possible to cover the entire surface of the scintillator layer 101b with the first protective film 102a substantially not bonded by combining the above methods 1) to 2) alone or in combination.
　第１保護フィルム１０２ａと平面受光素子２０１が実質的に接着していない状態にする方法としては次の方法が挙げられる。 As a method for making the first protective film 102a and the planar light receiving element 201 not substantially bonded, the following method may be mentioned.
　１）シンチレータパネル１ａと平面受光素子を重ねて配置したあと、第２保護フィルム側からスポンジ等のフォーム材の弾性を利用して適度な圧力で押し付ける方法
　上記の１）で、第１保護フィルム１０２ａと平面受光素子２０１で実質的に接着していない状態にすることができる。 1) A method in which the scintillator panel 1a and the planar light-receiving element are arranged so as to overlap each other and then pressed from the second protective film side with an appropriate pressure using the elasticity of a foam material such as a sponge. The planar light receiving element 201 can be substantially not adhered.
　保護フィルムの厚さは、空隙部の形成性、シンチレータ層の保護性、鮮鋭性、防湿性、作業性等を考慮し、１２μｍ以上、２００μｍ以下が好ましく、更には２０μｍ以上、４０μｍ以下が好ましい。厚さは、（株）テクロック製触針式膜厚計（ＰＧ－０１）により１０箇所を測定し平均した値を示す。 The thickness of the protective film is preferably 12 μm or more and 200 μm or less, more preferably 20 μm or more and 40 μm or less, taking into consideration the formation of voids, the scintillator layer protection, sharpness, moisture resistance, workability, and the like. The thickness indicates an average value obtained by measuring 10 points with a stylus stylus thickness meter (PG-01) manufactured by Teclock Co., Ltd.
　及び、ヘイズ率が、鮮鋭性、放射線画像ムラ、製造安定性、作業性等を考慮し、３％以上４０％以下が好ましく、更には３％以上、１０％以下が好ましい。ヘイズ率は、日本電色工業株式会社ＮＤＨ　５０００Ｗにより測定した値を示す。 The haze ratio is preferably 3% or more and 40% or less, more preferably 3% or more and 10% or less in consideration of sharpness, radiation image unevenness, manufacturing stability, workability, and the like. A haze rate shows the value measured by Nippon Denshoku Industries Co., Ltd. NDH 5000W.
　保護フィルムの光透過率は、光電変換効率、シンチレータ発光波長等を考慮し、５５０ｎｍで７０％以上あることが好ましいが、９９％以上の光透過率のフィルムは工業的に入手が困難であるため実質的に９９％～７０％が好ましい。光透過率は、株式会社日立ハイテクノロジーズ製分光光度計（Ｕ－１８００）で測定した値を示す。 The light transmittance of the protective film is preferably 70% or more at 550 nm in consideration of photoelectric conversion efficiency, scintillator emission wavelength, etc., but a film having a light transmittance of 99% or more is difficult to obtain industrially. Substantially 99% to 70% is preferable. The light transmittance is a value measured with a spectrophotometer (U-1800) manufactured by Hitachi High-Technologies Corporation.
　保護フィルムの透湿度は、シンチレータ層の保護性、潮解性等を考慮し５０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましく、更には１０ｇ／ｍ２・ｄａｙ（４０℃・９０％ＲＨ）（ＪＩＳ　Ｚ０２０８に準じて測定）以下が好ましい。 The moisture permeability of the protective film is preferably 50 g / m 2 · day (40 ° C., 90% RH) (measured in accordance with JIS Z0208) or less, more preferably 10 g / m in consideration of the scintillator layer protection, deliquescence and the like. 2 · day (40 ° C., 90% RH) (measured according to JIS Z0208) or less is preferable.
　本図に示す様にシンチレータプレート１０１を第１保護フィルム１０２ａと第２保護フィルム１０２ｂとで封止する方法は如何なる既知の方法でもかまわないが、例えばインパルスシーラーを使用した熱溶着で効率よく封止するため、保護フィルム１０２ａと保護フィルム１０２ｂとの接触する最内層を熱融着性を有する樹脂フィルムとすることが好ましい。 As shown in the figure, the scintillator plate 101 may be sealed with the first protective film 102a and the second protective film 102b by any known method. For example, the scintillator plate 101 can be efficiently sealed by thermal welding using an impulse sealer. For this reason, it is preferable that the innermost layer in contact between the protective film 102a and the protective film 102b is a resin film having heat-fusibility.
　図３は図２に示される空隙部１０８における光の屈折の状態と、従来の保護フィルムとシンチレータ層とが密着した状態における光の屈折の状態を示す模式図である。図３（ａ）は図２に示される空隙部１０８における光の屈折の状態を示す模式図である。図３（ｂ）は従来の保護フィルムとシンチレータ層とが密着した状態における光の屈折の状態を示す模式図である。 FIG. 3 is a schematic diagram showing the light refraction state in the gap 108 shown in FIG. 2 and the light refraction state in a state where the conventional protective film and the scintillator layer are in close contact with each other. FIG. 3A is a schematic diagram showing a state of light refraction in the gap 108 shown in FIG. FIG. 3B is a schematic diagram showing a state of light refraction in a state where the conventional protective film and the scintillator layer are in close contact with each other.
　図３（ａ）に示される場合は、保護フィルムとシンチレータ層との間に空隙部（空気層）１０８が存在する状態にあるため、第１保護フィルム１０２ａの屈折率と空隙部（空気層）１０８の屈折率との関係は、第１保護フィルムの屈折率＞＞空隙部（空気層）の屈折率となっている。このため、シンチレータ層面での発光した光Ｒ～Ｔは、第１保護フィルム１０２ａと空隙部（空気層）１０８の界面で反射されることなく（臨界角を有しない状態）保護フィルム内に入射し、入射した光は、空気層（低屈折率層）／保護フィルム／空気層と言う光学的対照構造により、保護フィルム－空気層界面で再反射することなく外部に放出されるため鮮鋭性の劣化の防止が可能となる。 In the case shown in FIG. 3A, since there is a void (air layer) 108 between the protective film and the scintillator layer, the refractive index of the first protective film 102a and the void (air layer) are present. The relationship with the refractive index of 108 is the refractive index of the first protective film >> the refractive index of the air gap (air layer). For this reason, the light R to T emitted from the scintillator layer is incident on the protective film without being reflected at the interface between the first protective film 102a and the air gap (air layer) 108 (in a state having no critical angle). The incident light is emitted to the outside without being re-reflected at the interface between the protective film and the air layer due to the optical contrast structure of air layer (low refractive index layer) / protective film / air layer. Can be prevented.
　図３（ｂ）に示される場合は、保護フィルムとシンチレータ層とが密着した状態にあるため、蛍光体面での発光した光Ｘ～Ｚの内、臨界角θを超える角度の光Ｚは保護層－空気層と言う光学的非対照構造により、界面で全反射される割合が多くなる。このため、鮮鋭性が劣化する原因の一つになる。 In the case shown in FIG. 3B, since the protective film and the scintillator layer are in close contact with each other, the light Z having an angle exceeding the critical angle θ is emitted from the light X to Z emitted from the phosphor surface. -The optical non-contrast structure called the air layer increases the proportion of total reflection at the interface. For this reason, it becomes one of the causes that sharpness deteriorates.
　本発明では、シンチレータプレートを第１保護フィルムと第２保護フィルムとにより封止するとき、図３（ａ）に示すようにシンチレータ層と第１保護フィルムの間を実質的に接着していない状態にすることと保護フィルムと平面受光素子面の間を実質的に接着していない状態にすることで鮮鋭性を劣化させないシンチレータパネルの製造が可能となった。 In the present invention, when the scintillator plate is sealed with the first protective film and the second protective film, the scintillator layer and the first protective film are not substantially adhered as shown in FIG. It becomes possible to manufacture a scintillator panel that does not deteriorate sharpness by making the protective film and the surface of the planar light receiving element substantially unbonded.
　また、基板を、厚さ５０μｍ以上５００μｍ以下の高分子フィルムとすること及びシンチレータパネルの総厚を１ｍｍ以下にすることでシンチレータパネルが平面受光素子面形状に合った形状に変形し、フラットパネルディテクタの受光面全体で均一な鮮鋭性が得られることが判明し、本発明に至った。 Further, by making the substrate into a polymer film having a thickness of 50 μm or more and 500 μm or less and making the total thickness of the scintillator panel to be 1 mm or less, the scintillator panel is deformed into a shape suitable for the planar light receiving element surface shape, and a flat panel detector It has been found that uniform sharpness can be obtained over the entire light receiving surface, and the present invention has been achieved.
　本発明では、図１～図３に示す様に、シンチレータプレートを第１保護フィルムと第２保護フィルムとにより封止するとき、シンチレータ層を覆う第１保護フィルムを実質的に接着していない状態とすることで（シンチレータ層と第１保護フィルムの間に点接触箇所を設け、点接触箇所の間に空隙部（空気層）を設ける）次の効果が得られた。 In the present invention, as shown in FIGS. 1 to 3, when the scintillator plate is sealed with the first protective film and the second protective film, the first protective film covering the scintillator layer is not substantially adhered. The following effects were obtained (providing a point contact location between the scintillator layer and the first protective film and providing a gap (air layer) between the point contact locations).
　１）強さの面で保護フィルムとして優れた物性を有していながら、屈折率が大であるために、鮮鋭性を低下させることから使用することが難しいかったポリプロプレンフィルムやポリエチレンテレフタレートフィルムやポリエチレンナフタレートフィルム等の使用が容易になり、高品質で長期の性能低下を防止したシンチレータパネルの製造が可能となった。 1) Polypropylene film and polyethylene terephthalate film which were difficult to use because of their high refractive index and low sharpness while having excellent physical properties as a protective film in terms of strength The use of polyethylene naphthalate film and the like has become easier, and it has become possible to produce scintillator panels that are of high quality and prevent long-term performance degradation.
　２）耐傷性の高い保護フィルムを、画質を劣化させることなく使用出来るようになるため、長期にわたる耐久性に優れたシンチレータパネルの実現が可能となった。 2) Since a highly scratch-resistant protective film can be used without degrading the image quality, it is possible to realize a scintillator panel with excellent durability over a long period of time.
　３）蛍光体結晶のライトガイド効果を阻害することなく、耐久性に優れた保護層が実現可能となった。 3) A protective layer with excellent durability can be realized without impeding the light guide effect of the phosphor crystal.
　図４は基板の上に気相堆積法でシンチレータ層を形成する蒸着装置の模式図である。 FIG. 4 is a schematic view of a vapor deposition apparatus for forming a scintillator layer on a substrate by a vapor deposition method.
　図中、２は蒸着装置を示す。蒸着装置２は、真空容器２０１と、真空容器２０１内に設けられて基板３に蒸気を蒸着させる蒸発源２０２と、基板３を保持する基板ホルダ２０３と、基板ホルダ２０３を蒸発源２０２に対して回転させることによって蒸発源２０２からの蒸気を蒸着させる基板回転機構２０４と、真空容器２０１内の排気及び大気の導入を行う真空ポンプ２０５等を備えている。 In the figure, 2 indicates a vapor deposition apparatus. The vapor deposition apparatus 2 includes a vacuum vessel 201, an evaporation source 202 that is provided in the vacuum vessel 201 and deposits vapor on the substrate 3, a substrate holder 203 that holds the substrate 3, and the substrate holder 203 with respect to the evaporation source 202. A substrate rotating mechanism 204 for depositing vapor from the evaporation source 202 by rotating, a vacuum pump 205 for exhausting the vacuum container 201 and introducing the atmosphere, and the like are provided.
　蒸発源２０２は、シンチレータ層形成材料を収容して抵抗加熱法で加熱するため、ヒータを巻いたアルミナ製のルツボから構成してもよいし、ボートや、高融点金属からなるヒータから構成してもよい。又、シンチレータ層形成材料を加熱する方法は、抵抗加熱法以外に電子ビームによる加熱や、高周波誘導による加熱等の方法でもよいが、本発明では、比較的簡単な構成で取り扱いが容易、安価、且つ、非常に多くの物質に適用可能である点から抵抗加熱法が好ましい。又、蒸発源２０２は分子源エピタキシャル法による分子線源でもよい。 Since the evaporation source 202 contains the scintillator layer forming material and is heated by a resistance heating method, the evaporation source 202 may be composed of an alumina crucible wound with a heater, or a boat or a heater made of a refractory metal. Also good. Further, the method of heating the scintillator layer forming material may be a method such as heating by an electron beam or heating by high frequency induction other than the resistance heating method, but in the present invention, it is easy to handle with a relatively simple configuration, inexpensive, In addition, the resistance heating method is preferable because it can be applied to a large number of substances. The evaporation source 202 may be a molecular beam source by a molecular source epitaxial method.
　支持体回転機構２０４は、例えば、基板ホルダ２０３を支持するとともに基板ホルダ２０４を回転させる回転軸２０４ａと、真空容器２０１外に配置されて回転軸２０４ａの駆動源となるモータ（図示しない）等から構成されている。 The support rotating mechanism 204 includes, for example, a rotating shaft 204a that supports the substrate holder 203 and rotates the substrate holder 204, and a motor (not shown) that is disposed outside the vacuum vessel 201 and serves as a driving source for the rotating shaft 204a. It is configured.
　又、基板ホルダ２０３には、基板３を加熱する加熱ヒータ（図示しない）を備えることが好ましい。基板３を加熱することによって、基板３の表面の吸着物を離脱・除去し、基板３の表面とシンチレータ層形成材料との間に不純物層の発生を防いだり、密着性の強化やシンチレータ層の膜質調整を行ったりすることが出来る。 The substrate holder 203 is preferably provided with a heater (not shown) for heating the substrate 3. By heating the substrate 3, the adsorbed material on the surface of the substrate 3 is separated and removed, and the generation of an impurity layer between the surface of the substrate 3 and the scintillator layer forming material is prevented. The film quality can be adjusted.
　更に、基板３と蒸発源２０２との間に、蒸発源２０２から基板３に至る空間を遮断するシャッタ（図示しない）を備えるようにしてもよい。シャッタによってシンチレータ層形成材料の表面に付着した目的物以外の物質が蒸着の初期段階で蒸発し、基板３に付着するのを防ぐことが出来る。 Furthermore, a shutter (not shown) that blocks the space from the evaporation source 202 to the substrate 3 may be provided between the substrate 3 and the evaporation source 202. It is possible to prevent substances other than the object attached to the surface of the scintillator layer forming material from evaporating at the initial stage of vapor deposition and adhering to the substrate 3 by the shutter.
　この様に構成された蒸着装置２を使用して、基板３にシンチレータ層を形成するには、まず、基板ホルダ２０３に支持体３を取り付ける。次いで、真空容器２０１内を真空排気する。その後、支持体回転機構２０４により基板ホルダ２０３を蒸発源２０２に対して回転させ、蒸着可能な真空度に真空容器２０１が達したら、加熱された蒸発源２０２からシンチレータ層形成材料を蒸発させて、基板３の表面に蛍光体を所望の厚さに成長させる。この場合において、基板３と蒸発源２０２の間隔は、１００～１５００ｍｍに設置するのが好ましく、２００～１０００ｍｍに設置するのがより好ましい。尚、蒸発源として使用するシンチレータ層形成材料は、加圧圧縮によりタブレットの形状に加工しておいてもよいし、粉末状態でもよい。又、シンチレータ層形成材料の代わりにその原料もしくは原料混合物を用いても構わない。なお蒸着時にはアルゴン等の不活性ガスを真空容器２０１の内部に導入し、当該真空容器２０１の内部を０．００１～５Ｐａ、より好ましくは０．０１～２Ｐａの真空雰囲気下に維持することが好ましい。また蛍光体層が形成される基板３の温度は、蒸着開始時は室温２５～５０℃に設定することが好ましく、蒸着中は１００～３００℃、より好ましくは１５０～２５０℃に設定することが好ましい。 In order to form a scintillator layer on the substrate 3 using the vapor deposition apparatus 2 configured in this way, first, the support 3 is attached to the substrate holder 203. Next, the vacuum vessel 201 is evacuated. Thereafter, the substrate holder 203 is rotated with respect to the evaporation source 202 by the support rotating mechanism 204, and when the vacuum container 201 reaches a vacuum degree capable of vapor deposition, the scintillator layer forming material is evaporated from the heated evaporation source 202, A phosphor is grown on the surface of the substrate 3 to a desired thickness. In this case, the distance between the substrate 3 and the evaporation source 202 is preferably set to 100 to 1500 mm, more preferably 200 to 1000 mm. The scintillator layer forming material used as the evaporation source may be processed into a tablet shape by pressure compression or may be in a powder state. Further, instead of the scintillator layer forming material, a raw material or a raw material mixture may be used. It is preferable that an inert gas such as argon is introduced into the vacuum vessel 201 during vapor deposition, and the inside of the vacuum vessel 201 is maintained in a vacuum atmosphere of 0.001 to 5 Pa, more preferably 0.01 to 2 Pa. . The temperature of the substrate 3 on which the phosphor layer is formed is preferably set to room temperature 25 to 50 ° C. at the start of vapor deposition, and is preferably set to 100 to 300 ° C., more preferably 150 to 250 ° C. during vapor deposition. preferable.
　（放射線画像変換パネル）
　本発明の放射線画像変換パネル（「放射線画像検出器」、「放射線フラットパネルディテクタ」ともいう。）は、基本的構成として、シンチレータパネルと平面受光素子を備えた態様の放射線画像変換パネルであることをようする。これにより、平面受光素子面がシンチレータパネルからの発光を電荷に変換することで画像をデジタルデータ化することが可能となる。 (Radiation image conversion panel)
The radiation image conversion panel (also referred to as “radiation image detector” or “radiation flat panel detector”) of the present invention is a radiation image conversion panel having a scintillator panel and a planar light receiving element as a basic configuration. Like As a result, the planar light receiving element surface converts the light emitted from the scintillator panel into electric charges, whereby the image can be converted into digital data.
　本発明に係る間接蒸着型（分離独立型）では、平面受光素子面上にシンチレータパネルを置く構成となる。この際、シンチレータパネルは平面受光素子面に物理化学的に接着されていない態様であることが好ましい。因みに、直接蒸着型（一体型）では、平面受光素子面に蛍光体の直接蒸着を行い平面受光素子とシンチレータ層が一体のシンチレータパネルとなる。 In the indirect vapor deposition type (separation independent type) according to the present invention, a scintillator panel is placed on the plane light receiving element surface. At this time, it is preferable that the scintillator panel is not physically bonded to the plane light receiving element surface. Incidentally, in the direct vapor deposition type (integrated type), the phosphor is directly vapor-deposited on the surface of the planar light receiving element to form a scintillator panel in which the planar light receiving element and the scintillator layer are integrated.
　なお、本発明に係る平面受光素子の表面平均粗さ（Ｒａ）は、０．００１～０．５μｍであることを要する。このため、ガラス表面に受光素子を形成後、表面にポリエステルやアクリルと言った有機樹脂膜を形成し、フォトエッチング法により表面粗さを制御することにより当該要件を満たすように調整する。平面受光素子の表面平均粗さ（Ｒａ）は０．００１～０．１μｍであることが好ましく、０．００１～０．０５μｍであることがより好ましい。 Note that the average surface roughness (Ra) of the planar light receiving element according to the present invention is required to be 0.001 to 0.5 μm. For this reason, after forming a light receiving element on the glass surface, an organic resin film such as polyester or acrylic is formed on the surface, and the surface roughness is controlled by a photoetching method so as to satisfy the requirements. The surface average roughness (Ra) of the planar light receiving element is preferably 0.001 to 0.1 μm, and more preferably 0.001 to 0.05 μm.
　本発明の放射線画像変換パネルは、シンチレータパネルが、平面受光素子に弾力部材（例えば、スポンジ、バネ等）により押しつけられ密着している態様であることが好ましい。また、シンチレータパネルが、当該シンチレータパネルと前記平面受光素子との間隙の気体の減圧により、当該平面受光素子に密着し、かつ周辺を密着シール部材でシールされている態様であることも好ましい。当該密着シール部材が、紫外線硬化型樹脂であることが好ましい。 The radiation image conversion panel of the present invention is preferably in such a mode that the scintillator panel is pressed and adhered to the planar light receiving element by an elastic member (for example, sponge, spring, etc.). In addition, it is also preferable that the scintillator panel is in a state in which the scintillator panel is in close contact with the planar light receiving element and the periphery thereof is sealed with a close seal member by reducing the gas in the gap between the scintillator panel and the planar light receiving element. The close seal member is preferably an ultraviolet curable resin.
　更に、当該シンチレータパネルがシンチレータ層を有し、かつ当該シンチレータ層が平面受光素子に直接的に密着している態様であることも好ましい。 Furthermore, it is also preferable that the scintillator panel has a scintillator layer and the scintillator layer is in direct contact with the planar light receiving element.
　紫外線硬化型樹脂としては特に制限はなく、従来から使用されているものの中から、適宜選択して用いることができる。この紫外線硬化型樹脂は、光重合性プレポリマー、または光重合性モノマー、光重合開始剤や光増感剤を含有するものである。 The ultraviolet curable resin is not particularly limited and can be appropriately selected from those conventionally used. This ultraviolet curable resin contains a photopolymerizable prepolymer, a photopolymerizable monomer, a photopolymerization initiator or a photosensitizer.
　前記光重合性プレポリマーとしては、例えばポリエステルアクリレート系、エポキシアクリレート系、ウレタンアクリレート系、ポリオールアクリレート系等が挙げられる。これらの光重合性プレポリマーは１種用いても良いし、２種以上を組み合わせて用いても良い。また，光重合性モノマーとしては、例えばポリメチロールプロパントリ（メタ）アクリレート、ヘキサンジオール（メタ）アクリレート、トリプロピレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート等が挙げられる。 Examples of the photopolymerizable prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate. These photopolymerizable prepolymers may be used alone or in combination of two or more. Examples of the photopolymerizable monomer include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate.
　本発明においては、プレポリマーとしてウレタンアクリレート系、モノマーとしてジペンタエリスリトールヘキサ（メタ）アクリレート等を用いることが好ましい。 In the present invention, it is preferable to use urethane acrylate as the prepolymer and dipentaerythritol hexa (meth) acrylate as the monomer.
　光重合開始剤としては、アセトフェノン類、ベンゾフェノン類、α－アミロキシムエステル、テトラメチルチュウラムモノサルファイド、チオキサントン類等が挙げられる。また、光増感剤としてｎ－ブチルアミン、トリエチルアミン、ポリ－ｎ－ブチルホスフィン等を混合して用いることができる。 Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, tetramethylchuram monosulfide, thioxanthones, and the like. Further, n-butylamine, triethylamine, poly-n-butylphosphine and the like can be mixed and used as a photosensitizer.
　以下、放射線画像変換パネルについて、図５及び図６を参照しながら、更に詳細な説明をする。 Hereinafter, the radiation image conversion panel will be described in more detail with reference to FIGS. 5 and 6.
　図５は放射線画像変換パネル１００の概略構成を示す一部破断斜視図である。また、図６は放射線画像変換パネル１００の拡大断面図である。 FIG. 5 is a partially broken perspective view showing a schematic configuration of the radiation image conversion panel 100. FIG. 6 is an enlarged sectional view of the radiation image conversion panel 100.
　図５に示す通り、放射線画像変換パネル１００には、撮像パネル５１、放射線画像変換パネル１００の動作を制御する制御部５２、書き換え可能な専用メモリ（例えば、フラッシュメモリ）等を用いて撮像パネル５１から出力された画像信号を記憶する記憶手段であるメモリ部５３、撮像パネル５１を駆動して画像信号を得るために必要とされる電力を供給する電力供給手段である電源部５４、等が筐体５５の内部に設けられている。 As shown in FIG. 5, the radiation image conversion panel 100 includes an imaging panel 51, a control unit 52 that controls the operation of the radiation image conversion panel 100, a rewritable dedicated memory (for example, a flash memory), and the like. A memory unit 53 that is a storage unit that stores an image signal output from the power source unit 54, a power supply unit 54 that is a power supply unit that supplies power necessary to obtain the image signal by driving the imaging panel 51, and the like. It is provided inside the body 55.
　筐体５５には、必要に応じて放射線画像変換パネル１００から外部に通信を行うための通信用のコネクタ５６、放射線画像変換パネル１００の動作を切り換えるための操作部５７、放射線画像の撮影準備の完了やメモリ部５３に所定量の画像信号が書き込まれたことを示す表示部５８、等が設けられている。 The housing 55 includes a communication connector 56 for performing communication from the radiation image conversion panel 100 to the outside as necessary, an operation unit 57 for switching the operation of the radiation image conversion panel 100, and preparation for radiographic image capturing. A display unit 58 that indicates completion or a predetermined amount of image signal has been written in the memory unit 53 is provided.
　ここで、放射線画像変換パネル１００に電源部５４を設けるとともに放射線画像の画像信号を記憶するメモリ部５３を設け、コネクタ５６を介して放射線画像検出器１００を着脱自在にすれば、放射線画像変換パネル１００を持ち運びできる可搬構造とすることができる。 Here, if the radiation image conversion panel 100 is provided with the power supply unit 54 and the memory unit 53 for storing the image signal of the radiation image, and the radiation image detector 100 is detachable via the connector 56, the radiation image conversion panel. It can be set as the portable structure which can carry 100.
　図５に示すように、撮像パネル５１は、放射線用シンチレータパネル１０と、シンチレータパネル１０からの電磁波を吸収して画像信号を出力する出力基板２０とから構成されている。 As shown in FIG. 5, the imaging panel 51 includes a radiation scintillator panel 10 and an output substrate 20 that absorbs electromagnetic waves from the scintillator panel 10 and outputs an image signal.
　シンチレータパネル１０は放射線照射面側に配置されており、入射した放射線の強度に応じた電磁波を発光するように構成されている。 The scintillator panel 10 is disposed on the radiation irradiation surface side and is configured to emit an electromagnetic wave corresponding to the intensity of incident radiation.
　出力基板２０は、シンチレータパネル１０の放射線照射面と反対側の面に設けられており、放射線用シンチレータパネル１０側から順に、隔膜２０ａ、光電変換素子２０ｂ、画像信号出力層２０ｃ及び基板２０ｄを備えている。隔膜２０ａは、放射線用シンチレータパネル１０と他の層を分離するためのものである。 The output substrate 20 is provided on the surface opposite to the radiation irradiation surface of the scintillator panel 10, and includes a diaphragm 20a, a photoelectric conversion element 20b, an image signal output layer 20c, and a substrate 20d in order from the radiation scintillator panel 10 side. ing. The diaphragm 20a is used to separate the radiation scintillator panel 10 from other layers.
　光電変換素子２０ｂは、透明電極２１と、透明電極２１を透過して入光した電磁波により励起されて電荷を発生する電荷発生層２２と、透明電極２１に対しての対極になる対電極２３とから構成されており、隔膜２０ａ側から順に透明電極２１、電荷発生層２２、対電極２３が配置される。 The photoelectric conversion element 20 b includes a transparent electrode 21, a charge generation layer 22 that is excited by electromagnetic waves that have passed through the transparent electrode 21 to enter the light, and generates a charge, and a counter electrode 23 that is a counter electrode for the transparent electrode 21. The transparent electrode 21, the charge generation layer 22, and the counter electrode 23 are arranged in this order from the diaphragm 20a side.
　透明電極２１とは、光電変換される電磁波を透過させる電極であり、例えば、インジウムチンオキシド（ＩＴＯ）、ＳｎＯ２、ＺｎＯなどの導電性透明材料を用いて形成される。 The transparent electrode 21 is an electrode that transmits an electromagnetic wave that is photoelectrically converted, and is formed using a conductive transparent material such as indium tin oxide (ITO), SnO 2 , or ZnO.
　電荷発生層２２は、透明電極２１の一面側に薄膜状に形成されており、光電変換可能な化合物として光によって電荷分離する有機化合物を含有するものであり、電荷を発生し得る電子供与体及び電子受容体としての導電性化合物をそれぞれ含有している。電荷発生層２２では、電磁波が入射されると電子供与体は励起されて電子を放出し、放出された電子は電子受容体に移動して、電荷発生層２２内に電荷、即ち正孔と電子のキャリアが発生するようになっている。 The charge generation layer 22 is formed in a thin film on one surface side of the transparent electrode 21 and contains an organic compound that separates charges by light as a compound capable of photoelectric conversion. Each of them contains a conductive compound as an electron acceptor. In the charge generation layer 22, when an electromagnetic wave is incident, the electron donor is excited to emit electrons, and the emitted electrons move to the electron acceptor, and charge, that is, holes and electrons, are transferred into the charge generation layer 22. Career is going to occur.
　ここで、電子供与体としての導電性化合物としては、ｐ型導電性高分子化合物が挙げられ、ｐ型導電性高分子化合物としては、ポリフェニレンビニレン、ポリチオフェン、ポリ（チオフェンビニレン）、ポリアセチレン、ポリピロール、ポリフルオレン、ポリ（ｐ－フェニレン）またはポリアニリンの基本骨格を持つものが好ましい。 Here, examples of the conductive compound as the electron donor include a p-type conductive polymer compound. Examples of the p-type conductive polymer compound include polyphenylene vinylene, polythiophene, poly (thiophene vinylene), polyacetylene, polypyrrole, Those having a basic skeleton of polyfluorene, poly (p-phenylene) or polyaniline are preferred.
　また、電子受容体としての導電性化合物としてはｎ型導電性高分子化合物が挙げられ、ｎ型導電性高分子化合物としてはポリピリジンの基本骨格を持つものが好ましく、特にポリ（ｐ－ピリジルビニレン）の基本骨格を持つものが好ましい。 Examples of the conductive compound as the electron acceptor include an n-type conductive polymer compound. The n-type conductive polymer compound preferably has a polypyridine basic skeleton, and in particular, poly (p-pyridylvinylene). Those having the following basic skeleton are preferred.
　電荷発生層２２の膜厚は、光吸収量を確保するといった観点から１０ｎｍ以上（特に１００ｎｍ以上）が好ましく、また電気抵抗が大きくなりすぎないといった観点から、１μｍ以下（特に３００ｎｍ以下）が好ましい。 The film thickness of the charge generation layer 22 is preferably 10 nm or more (particularly 100 nm or more) from the viewpoint of securing the amount of light absorption, and is preferably 1 μm or less (particularly 300 nm or less) from the viewpoint that the electric resistance does not become too large.
　対電極２３は、電荷発生層２２の電磁波が入光される側の面と反対側に配置されている。対電極２３は、例えば、金、銀、アルミニウム、クロムなどの一般の金属電極や、透明電極２１の中から選択して用いることが可能であるが、良好な特性を得るためには仕事関数の小さい（４．５ｅＶ以下）金属、合金、電気伝導性化合物及びこれらの混合物を電極物質とするのが好ましい。 The counter electrode 23 is disposed on the opposite side of the surface of the charge generation layer 22 where the electromagnetic wave is incident. The counter electrode 23 can be selected and used from, for example, a general metal electrode such as gold, silver, aluminum, and chromium, or the transparent electrode 21. Small (4.5 eV or less) metals, alloys, electrically conductive compounds and mixtures thereof are preferably used as electrode materials.
　また、電荷発生層２２を挟む各電極（透明電極２１及び対電極２３）との間には、電荷発生層２２とこれら電極が反応しないように緩衝地帯として作用させるためのバッファー層を設けてもよい。バッファー層は、例えば、フッ化リチウム及びポリ（３，４－エチレンジオキシチオフェン）、ポリ（４－スチレンスルホナート）、２，９－ジメチル－４，７－ジフェニル［１，１０］フェナントロリンなどを用いて形成される。 In addition, a buffer layer may be provided between each electrode (transparent electrode 21 and counter electrode 23) sandwiching the charge generation layer 22 so as to act as a buffer zone so that the charge generation layer 22 and these electrodes do not react. Good. Examples of the buffer layer include lithium fluoride and poly (3,4-ethylenedioxythiophene), poly (4-styrenesulfonate), 2,9-dimethyl-4,7-diphenyl [1,10] phenanthroline, and the like. Formed using.
　画像信号出力層２０ｃは、光電変換素子２０ｂで得られた電荷の蓄積及び蓄積された電荷に基づく信号の出力を行うものであり、光電変換素子２０ｂで生成された電荷を画素毎に蓄積する電荷蓄積素子であるコンデンサ２４と、蓄積された電荷を信号として出力する画像信号出力素子であるトランジスタ２５とを用いて構成されている。 The image signal output layer 20c performs accumulation of charges obtained by the photoelectric conversion element 20b and output of a signal based on the accumulated charges. Charge for accumulating the charges generated by the photoelectric conversion element 20b for each pixel. The capacitor 24 is a storage element, and the transistor 25 is an image signal output element that outputs the stored charge as a signal.
　トランジスタ２５は、例えば、ＴＦＴ（薄膜トランジスタ）を用いるものとする。このＴＦＴは液晶ディスプレイ等に使用されている無機半導体系のものでも、有機半導体を用いたものでもよく、好ましくはプラスチックフィルム上に形成されたＴＦＴである。 As the transistor 25, for example, a TFT (Thin Film Transistor) is used. This TFT may be an inorganic semiconductor type used in a liquid crystal display or the like or an organic semiconductor, and is preferably a TFT formed on a plastic film.
　プラスチックフィルム上に形成されたＴＦＴとしては、アモルファスシリコン系のものが知られているが、その他、米国Ａｌｉｅｎ　Ｔｅｃｈｎｏｌｏｇｙ社が開発しているＦＳＡ（Ｆｌｕｉｄｉｃ　Ｓｅｌｆ　Ａｓｓｅｍｂｌｙ）技術、即ち単結晶シリコンで作製した微小ＣＭＯＳ（Ｎａｎｏｂｌｏｃｋｓ）をエンボス加工したプラスチックフィルム上に配列させることで、フレキシブルなプラスチックフィルム上にＴＦＴを形成するものとしてもよい。更に、Ｓｃｉｅｎｃｅ，２８３，８２２（１９９９）やＡｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ，７７１４８８（１９９８）、Ｎａｔｕｒｅ，４０３，５２１（２０００）等の文献に記載されているような、有機半導体を用いたＴＦＴであってもよい。 As TFTs formed on plastic films, amorphous silicon-based TFTs are known, but in addition, FSA (Fluidic Self Assembly) technology developed by Alien Technology in the United States, that is, microfabricated with single crystal silicon. TFTs may be formed on a flexible plastic film by arranging CMOS (Nanoblocks) on an embossed plastic film. Furthermore, Science, 283, 822 (1999) and Appl. Phys. It may be a TFT using an organic semiconductor as described in documents such as Lett, 771488 (1998), Nature, 403, 521 (2000).
　このように、本発明に用いられるトランジスタ２５としては、上記ＦＳＡ技術で作製したＴＦＴ及び有機半導体を用いたＴＦＴが好ましく、特に好ましいものは有機半導体を用いたＴＦＴである。この有機半導体を用いてＴＦＴを構成すれば、シリコンを用いてＴＦＴを構成する場合のように真空蒸着装置等の設備が不要となり、印刷技術やインクジェット技術を活用してＴＦＴを形成できるので製造コストが安価となる。更に加工温度を低くできることから、熱に弱いプラスチック基板上にも形成できる。 Thus, as the transistor 25 used in the present invention, a TFT manufactured by the FSA technique and a TFT using an organic semiconductor are preferable, and a TFT using an organic semiconductor is particularly preferable. If this organic semiconductor is used to form a TFT, equipment such as a vacuum deposition apparatus is not required as in the case where a TFT is formed using silicon, and the TFT can be formed using printing technology or inkjet technology. Is cheaper. Further, since the processing temperature can be lowered, it can be formed on a plastic substrate that is weak against heat.
　トランジスタ２５には、光電変換素子２０ｂで発生した電荷を蓄積するとともに、コンデンサ２４の一方の電極となる収集電極（図示せず）が電気的に接続されている。コンデンサ２４には光電変換素子２０ｂで生成された電荷が蓄積されるとともに、この蓄積された電荷はトランジスタ２５を駆動することで読み出される。即ち、トランジスタ２５を駆動させることで、放射線画像の画素毎の信号を出力させることができる。 The transistor 25 accumulates electric charges generated in the photoelectric conversion element 20b and is electrically connected to a collecting electrode (not shown) serving as one electrode of the capacitor 24. The capacitor 24 accumulates charges generated by the photoelectric conversion element 20 b and reads the accumulated charges by driving the transistor 25. That is, by driving the transistor 25, a signal for each pixel of the radiation image can be output.
　基板２０ｄは、撮像パネル５１の支持体として機能するものであり、基板１と同様の素材で構成することが可能である。 The substrate 20d functions as a support for the imaging panel 51, and can be made of the same material as the substrate 1.
　次に、放射線画像変換パネル１００の作用について説明する。 Next, the operation of the radiation image conversion panel 100 will be described.
　先ず放射線画像変換パネル１００に対し入射された放射線は、撮像パネル５１のシンチレータパネル１０側から基板２０ｄ側に向けて放射線を入射する。すると、放射線用シンチレータパネル１０に入射された放射線は、シンチレータパネル１０中のシンチレータ層２が放射線のエネルギーを吸収し、その強度に応じた電磁波を発光する。 First, the radiation incident on the radiation image conversion panel 100 enters the imaging panel 51 from the scintillator panel 10 side toward the substrate 20d side. Then, the radiation incident on the radiation scintillator panel 10 is absorbed by the scintillator layer 2 in the scintillator panel 10 and emits an electromagnetic wave corresponding to its intensity.
　発光された電磁波の内、出力基板２０に入光される電磁波は出力基板２０の隔膜２０ａ、透明電極２１を貫通し、電荷発生層２２に到達する。そして、電荷発生層２２において電磁波は吸収され、その強度に応じて正孔と電子のペア（電荷分離状態）が形成される。 Among the emitted electromagnetic waves, the electromagnetic waves entering the output substrate 20 pass through the diaphragm 20a and the transparent electrode 21 of the output substrate 20 and reach the charge generation layer 22. Then, the electromagnetic wave is absorbed in the charge generation layer 22 and a hole-electron pair (charge separation state) is formed according to the intensity.
　その後、発生した電荷は、電源部５４によるバイアス電圧の印加により生じる内部電界により、正孔と電子はそれぞれ異なる電極（透明電極膜及び導電層）へ運ばれ、光電流が流れる。 Thereafter, the generated electric charges are transported to different electrodes (transparent electrode film and conductive layer) by an internal electric field generated by application of a bias voltage by the power supply unit 54, and a photocurrent flows.
　その後、対電極２３側に運ばれた正孔は画像信号出力層２０ｃのコンデンサ２４に蓄積される。蓄積された正孔はコンデンサ２４に接続されているトランジスタ２５を駆動させると、画像信号を出力するとともに、出力された画像信号はメモリ部５３に記憶される。 Thereafter, the holes carried to the counter electrode 23 side are accumulated in the capacitor 24 of the image signal output layer 20c. The accumulated holes output an image signal when the transistor 25 connected to the capacitor 24 is driven, and the output image signal is stored in the memory unit 53.
　以上の放射線画像変換パネル１００によれば、上記シンチレータパネル１０を備えているので光電変換効率を高めることができ、放射線画像における低線量撮影時のＳＮ比を向上させるとともに、画像ムラや線状ノイズの発生を防止することができる。 According to the radiation image conversion panel 100 described above, since the scintillator panel 10 is provided, the photoelectric conversion efficiency can be increased, the SN ratio at the time of low-dose imaging in a radiation image is improved, and image unevenness and linear noise are improved. Can be prevented.
　（Ｘ線撮影システム）
　本発明の放射線画像変換パネルは、可搬性容器に配置し、Ｘ線を曝射し、放射線画像の読み取りを行う態様のＸ線撮影システムに好適に用いることができる。 (X-ray imaging system)
The radiographic image conversion panel of the present invention can be suitably used in an X-ray imaging system of an aspect in which a radiographic image is read by placing X-rays on a portable container.
　可搬性容器は撮影時にベット上で患者の下に差し込んだりでき、小型であるため様々な撮影形態に対応できる。しかし、可搬性容器は持ち運びが容易である反面、落下や衝撃を受けやすく、その場合にシンチレータとＴＦＴにズレや空気が入り込むことによる画像ボケが生じやすい。本発明では、シンチレータとＴＦＴとの密着性が向上するため、可搬性容器に配置される場合に好ましい。 The portable container can be inserted under the patient on the bed at the time of imaging, and can be used in various imaging modes due to its small size. However, while the portable container is easy to carry, it is susceptible to dropping and impact, and in this case, image blurring due to displacement and air entering the scintillator and TFT tends to occur. In this invention, since the adhesiveness of a scintillator and TFT improves, it is preferable when arrange | positioning to a portable container.
　以下、実施例を挙げて本発明を詳細に説明するが、本発明はこれらに限定されない。 Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.
　実施例１
　（シンチレータシートの作製）
　（基板の準備）
　基板として、Ａｒガス中でプラズマ処理を施した厚さ０．２５ｍｍのポリイミド基板（９０ｍｍ×９０ｍｍ）と０．５ｍｍのガラス基板を準備した。 Example 1
(Preparation of scintillator sheet)
(Preparation of substrate)
As a substrate, a polyimide substrate (90 mm × 90 mm) having a thickness of 0.25 mm and subjected to plasma treatment in Ar gas and a glass substrate having a thickness of 0.5 mm were prepared.
　（蛍光体層の形成）
　図４に示す蒸着装置を使用して、準備した基板に蛍光体（ＣｓＩ：０．００３Ｔｌ）を蒸着させ蛍光体層を形成し、シンチレータシートを作製した。 (Formation of phosphor layer)
Using the vapor deposition apparatus shown in FIG. 4, a phosphor (CsI: 0.003Tl) was deposited on the prepared substrate to form a phosphor layer, and a scintillator sheet was produced.
　蛍光体原料（ＣｓＩ：０．００３Ｔｌ）を抵抗加熱ルツボに充填し、支持体ホルダにポリイミド基板を設置し、抵抗加熱ルツボと基板との間隔を４００ｍｍに調節した。続いて蒸着装置内を一旦排気し、Ａｒガスを導入して０．５Ｐａに真空度を調整した後、１０ｒｐｍの速度で基板を回転しながら基板の温度を１５０℃に保持した。次いで、抵抗加熱ルツボを加熱して蛍光体を蒸着し蛍光体層の膜厚が４００μｍとなったところで蒸着を終了した。 Fluorescent material (CsI: 0.003 Tl) was filled in a resistance heating crucible, a polyimide substrate was placed on the support holder, and the distance between the resistance heating crucible and the substrate was adjusted to 400 mm. Subsequently, the inside of the vapor deposition apparatus was once evacuated, Ar gas was introduced and the degree of vacuum was adjusted to 0.5 Pa, and then the substrate temperature was maintained at 150 ° C. while rotating the substrate at a speed of 10 rpm. Next, the resistance heating crucible was heated to deposit the phosphor, and the deposition was terminated when the thickness of the phosphor layer reached 400 μm.
　（保護フィルムの準備）
　蛍光体面側の保護フィルムとして、表１に示す様に表面粗さを変えた厚さ３０μｍのポリプロピレンフィルム（ＰＰ）を用意し、Ｎｏ．１～５、７～１５とした。尚、表面粗さの調整は、使用するＰＰを市販されているＰＰより適宜選択することで表面粗さを調整した。（尚、ＰＰフィルムの表面粗さは表裏で同一なものを使用した）
　シンチレータシートの基板側の保護フィルムは、蛍光体面側の保護フィルムと同じものを使用した。 (Preparation of protective film)
As a protective film on the phosphor surface side, a polypropylene film (PP) having a thickness of 30 μm with a surface roughness changed as shown in Table 1 was prepared. 1 to 5 and 7 to 15. The surface roughness was adjusted by appropriately selecting the PP to be used from commercially available PP. (The surface roughness of the PP film was the same on both sides)
The same protective film on the phosphor surface side was used as the protective film on the substrate side of the scintillator sheet.
　表面粗さは、東京精密（株）製サーフコム１４００Ｄにより測定した。（カットオフ値は０．８ｍｍ）
　（シンチレータパネルの作製）
　準備したシンチレータシートを、準備した保護フィルムＮｏ．１～５、７～１５を使用し、図１（ｃ）に示す形態に封止しシンチレータパネルを作製し、試料Ｎｏ．１～５、７～１５とした。融着部からシンチレータシートの周縁部までの距離は１ｍｍとなるように融着した。融着に使用したインパルスシーラーのヒータは３ｍｍ幅のものを使用した。 The surface roughness was measured with Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd. (Cutoff value is 0.8mm)
(Production of scintillator panel)
The prepared scintillator sheet was prepared from the prepared protective film No. 1 to 5 and 7 to 15 were used and sealed in the form shown in FIG. 1 to 5 and 7 to 15. Fusion was performed such that the distance from the fusion part to the peripheral part of the scintillator sheet was 1 mm. The impulse sealer used for the fusion was a 3 mm wide heater.
　尚、試料Ｎｏ．６は、シンチレータシートに保護層を設けず、ＴＦＴ基板と貼り合わせ、減圧１０００Ｐａ条件下で、周囲を紫外線硬化樹脂でシールした。 Sample No. In No. 6, a protective layer was not provided on the scintillator sheet, and the scintillator sheet was bonded to a TFT substrate, and the surroundings were sealed with an ultraviolet curable resin under reduced pressure of 1000 Pa.
　〈評価〉
　得られた各試料Ｎｏ．１～１５に付き、１０ｃｍ×１０ｃｍの大きさのＣＭＯＳフラットパネル（ラドアイコン社製Ｘ線ＣＭＯＳカメラシステムＳｈａｄ－ｏ－Ｂｏｘ４ＫＥＶ）にセットし、１２ｂｉｔの出力データより鮮鋭性を封止した後、以下に示す方法で測定し、以下に示す評価ランクにより評価した結果を表２に示す。 <Evaluation>
Each obtained sample No. Set to a 10cm x 10cm size CMOS flat panel (Radicon X-ray CMOS camera system Shad-o-Box4KEV) from 1 to 15 and seal the sharpness from the 12-bit output data. Table 2 shows the results of measurement by the method shown in FIG.
　尚、放射線入射窓のカーボン板とシンチレータパネルの放射線入射側（蛍光体のない側）にスポンジシートを配置し、平面受光素子面とシンチレータパネルを軽く押し付けることで両者を固定化した。 In addition, a sponge sheet was placed on the radiation incident side (the side without the phosphor) of the radiation incident window carbon plate and the scintillator panel, and both were fixed by lightly pressing the plane light receiving element surface and the scintillator panel.
　〈鮮鋭性の評価方法〉
　ＣＴＦチャートを放射線画像変換パネル上に設置し、管電圧８０ｋＶ、線量２０ｍＡｓ、管球距離１ｍの条件でＸ線を曝射しチャートの再現性より空間周波数１ｌｎ／ｍｍのＭＴＦを求めた。ＭＴＦはサンプル１を１００とする相対値で求めた。 <Evaluation method of sharpness>
A CTF chart was placed on the radiation image conversion panel, and X-rays were irradiated under conditions of tube voltage 80 kV, dose 20 mAs, tube distance 1 m, and MTF with a spatial frequency of 1 ln / mm was obtained from the reproducibility of the chart. The MTF was determined as a relative value with Sample 1 as 100.
　〈画像ムラの評価方法〉
　放射線画像変換パネルの全面に管電圧７０ｋＶ、線量２０ｍＡｓ、管球距離１ｍで照射し、画像を取得した。得られた画像をコニカミルタエムジー社製ドライプロ７２２を使用し出力しシャーカステンにて、下記基準に基づき、目視評価を行った。 <Evaluation method of image unevenness>
The entire surface of the radiation image conversion panel was irradiated with a tube voltage of 70 kV, a dose of 20 mAs, and a tube distance of 1 m, and an image was acquired. The obtained image was output using a dry pro 722 manufactured by Konica Milta MG Co., Ltd., and visually evaluated with a Schaukasten based on the following criteria.
　評価基準：
　６：ムラが無い、もしくは目視で分からない。 Evaluation criteria:
6: There is no unevenness or it cannot be visually confirmed.
　５：ムラが存在するが、その面積が画像部の２０％以下
　４：ムラが存在し、その面積が画像部の２０％～４０％であるが使用できる
　３：ムラが存在し、その面積が画像部の４０％～６０％
　２：ムラが存在し、その面積が画像部の６０％～８０％
　１：ムラが存在し、その面積が画像部の８０％以上であり、使用できない。 5: Unevenness exists, but the area is 20% or less of the image part 4: Unevenness exists and the area is 20% to 40% of the image part, but can be used 3: Unevenness exists and the area is 40% to 60% of the image area
2: There is unevenness, and the area is 60% to 80% of the image area
1: There is unevenness, and the area is 80% or more of the image portion and cannot be used.
　評価結果を表１にまとめて示す。 Evaluation results are summarized in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示した結果から明らかなように、本発明に係るサンプルの鮮鋭性は優れており、かつ画像ムラが少なく優れていることが分かる。 As is apparent from the results shown in Table 1, it can be seen that the sample according to the present invention is excellent in sharpness and excellent in image unevenness.

Claims (9)

  1. シンチレータパネルと平面受光素子を備えた放射線画像変換パネルであって、当該シンチレータパネルの平面受光素子と対向する側の表面平均粗さ（Ｒａ）が０．０１～３．０μｍ、かつ当該平面受光素子のシンチレータパネルと対向する側の表面平均粗さ（Ｒａ）が０．００１～０．５μｍであることを特徴とする放射線画像変換パネル。 A radiation image conversion panel including a scintillator panel and a planar light receiving element, wherein the surface average roughness (Ra) on the side of the scintillator panel facing the planar light receiving element is 0.01 to 3.0 μm, and the planar light receiving element A radiation image conversion panel having an average surface roughness (Ra) on the side facing the scintillator panel of 0.001 to 0.5 μm.
  2. 前記シンチレータパネルが、前記平面受光素子に弾力部材により押しつけられ密着していることを特徴とする請求の範囲第１項に記載の放射線画像変換パネル。 The radiation image conversion panel according to claim 1, wherein the scintillator panel is pressed against and adhered to the planar light receiving element by an elastic member.
  3. 前記シンチレータパネルが、当該シンチレータパネルと前記平面受光素子との間隙の気体の減圧により、当該平面受光素子に密着し、かつ周辺を密着シール部材でシールされていることを特徴とする請求の範囲第１項に記載の放射線画像変換パネル。 The scintillator panel is in close contact with the planar light receiving element by the pressure reduction of the gas in the gap between the scintillator panel and the planar light receiving element, and the periphery is sealed with a tight seal member. The radiation image conversion panel according to item 1.
  4. 前記シンチレータパネルが、可撓性を有していることを特徴とする請求の範囲第１項から第３項のいずれか一項に記載の放射線画像変換パネル。 The radiographic image conversion panel according to any one of claims 1 to 3, wherein the scintillator panel has flexibility.
  5. 前記密着シール部材が、紫外線硬化型樹脂であることを特徴とする請求の範囲第３項又は第４項に記載の放射線画像変換パネル。 The radiation image conversion panel according to claim 3 or 4, wherein the adhesion seal member is an ultraviolet curable resin.
  6. 前記シンチレータパネルがシンチレータ層を有し、かつ当該シンチレータ層が平面受光素子に直接的に密着していることを特徴とする請求の範囲第１項から第５項のいずれか一項に記載の放射線画像変換パネル。 The radiation according to any one of claims 1 to 5, wherein the scintillator panel has a scintillator layer, and the scintillator layer is in direct contact with the planar light receiving element. Image conversion panel.
  7. 前記シンチレータ層が、ヨウ化セシウム（ＣｓＩ）を主成分として含有することを特徴とする請求の範囲第６項に記載の放射線画像変換パネル。 The radiation image conversion panel according to claim 6, wherein the scintillator layer contains cesium iodide (CsI) as a main component.
  8. 前記シンチレータ層が、気相堆積法により形成された蛍光体柱状結晶であることを特徴とする請求の範囲第６項又は第７項に記載の放射線画像変換パネル。 8. The radiation image conversion panel according to claim 6, wherein the scintillator layer is a phosphor columnar crystal formed by a vapor deposition method.
  9. 請求の範囲第１項から第８項のいずれか一項に記載の放射線画像変換パネルを可搬性容器に配置し、Ｘ線を曝射し、放射線画像の読み取りを行うことを特徴とするＸ線撮影システム。 An X-ray characterized in that the radiation image conversion panel according to any one of claims 1 to 8 is placed in a portable container, X-rays are irradiated, and a radiation image is read. Shooting system.
PCT/JP2009/054412 2008-07-25 2009-03-09 Radiation image conversion panel and radiographic apparatus using the same WO2010010728A1 (en)

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JP2006337184A (en) * 2005-06-02 2006-12-14 Canon Inc Radiation detector
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