JP2012159305A - Radiation image conversion panel and radiation image detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve image quality of a radiation image acquired by a radiation image detector.SOLUTION: The radiation image detector 1 includes: a radiation image conversion panel 2 which is equipped with a phosphor 18 containing a fluorescent material for emitting fluorescence by radiation exposure; and a sensor panel 3 which detects the fluorescence emitted from the radiation image conversion panel. The phosphor 18 includes a group of columnar crystals 35 by growing crystals of the fluorescent material into a columnar shape. In each columnar crystal 35, at least the tip 35A is formed in a tapered shape, and the side surface in at least the tip 35A out of the side surfaces thereof is covered with a reflection film 40. The radiation image conversion panel 2 and the sensor panel 3 are adhered to each other so that the surface of the phosphor 18 corresponding to the tip side of each columnar crystal 35 is opposed to the sensor panel 3.

Description

  The present invention relates to a radiation image conversion panel and a radiation image detection apparatus.

  In recent years, a radiation image detection apparatus using an FPD (Flat Panel Detector) that detects a radiation image and generates digital image data has been put into practical use, because the image can be confirmed immediately compared to a conventional imaging plate. It is spreading rapidly. There are various types of radiological image detection apparatuses, and one of them is an indirect conversion type.

An indirect conversion type radiation image detection apparatus includes a radiation image conversion panel having a scintillator formed of a fluorescent material such as CsI or GOS (Gd ₂ O ₂ S) that emits fluorescence by radiation exposure, and a two-dimensional array of photoelectric conversion elements. Typically, the radiation image conversion panel and the sensor panel are bonded together with an adhesive layer interposed between the scintillator and the sensor panel. The radiation that has passed through the subject is once converted into light by the scintillator of the radiation image conversion panel, and the fluorescence of the scintillator is photoelectrically converted by the photoelectric conversion element group of the sensor panel to generate an electrical signal (digital image data).

  In the indirect conversion type radiological image detection apparatus, a so-called surface reading type (ISS: Irradiation Side Sampling) radiological image detection apparatus in which radiation is incident from the sensor panel side has also been proposed (see, for example, Patent Document 1). ). According to this radiological image detection apparatus, the amount of fluorescence generated in the vicinity of the sensor panel of the scintillator increases, and the sensitivity can be improved. Thereby, the radiation exposure amount can be reduced and the exposure amount of the subject can be reduced.

  Also known is a technique for forming a scintillator by a group of columnar crystals obtained by growing a crystal of a fluorescent substance such as CsI in a columnar shape on a support by vapor deposition (see, for example, Patent Documents 2 and 3). ). Columnar crystals formed by vapor deposition do not contain impurities such as binders, and also have a light guide effect that guides the fluorescence generated there in the direction of crystal growth, suppressing the diffusion of fluorescence. To do. Thereby, the sensitivity of the radiation image detection device and the sharpness of the image are improved.

  Since CsI used as a fluorescent material has deliquescence, a scintillator formed using CsI is generally covered with a protective film having moisture resistance. By the way, the protective film may enter between the columnar crystals of the scintillator. For example, a polyethylene terephthalate film or a parylene film formed by chemical vapor deposition (CVD) is used as the protective film, but these typically have a refractive index higher than that of air interposed between columnar crystals. Therefore, when the protective film enters between the columnar crystals, the light guide effect of the columnar crystals using total reflection due to a difference in refractive index from air is reduced.

  In the scintillator described in Patent Document 2, in order to maintain the light guide effect of the columnar crystals, the end portions of the columnar crystals are made flat, and between the columnar crystals by a filler having a lower refractive index than the protective film. Is buried. When the protective film is a film, the tip of the columnar crystal is flattened so that the columnar crystal is less likely to pierce the protective film, and when the protective film is a film formed by the CVD method By making the tip of the columnar crystal flat, the gap between the columnar crystals is narrowed and the gap is closed at the initial stage of film formation, and the protective film is difficult to enter between the columnar crystals. Even if the protective film enters between the columnar crystals, the space between the columnar crystals is filled with a low refractive index filler, thereby preventing the protective film from contacting the side surfaces of the columnar crystals.

JP 2001-330677 A JP 2010-025620 A JP 2011-017683 A

  If the tip of the columnar crystal is flat, the emission angle of fluorescence from the tip of the columnar crystal may be large. Since a protective film and an adhesive layer are interposed between the scintillator and the sensor panel, the fluorescence emitted from the tip of the columnar crystal at a relatively large emission angle is a photoelectric conversion element that the columnar crystal faces. There is a risk that it will be incident on a surrounding photoelectric conversion element different from the above, and this may reduce the sharpness of the image.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to improve the image quality of a radiographic image acquired by a radiographic image detection apparatus.

(1) A radiation image conversion panel including a phosphor containing a phosphor that emits fluorescence by radiation exposure, wherein the phosphor includes a group of columnar crystals formed by growing crystals of the phosphor in a columnar shape, Each columnar crystal is a radiation image conversion panel in which at least a tip portion is formed in a tapered shape, and at least a side surface of the tip portion of the columnar crystal is covered with a reflective film.
(2) The radiation image conversion panel according to (1) above and a sensor panel that detects fluorescence emitted from the radiation image conversion panel, and the surface of the phosphor that corresponds to the tip side of each columnar crystal is the sensor panel. A radiographic image detection apparatus in which the radiographic image conversion panel and the sensor panel are bonded to each other.

  According to the present invention, the tip of the columnar crystal is tapered and tapered, and the side surface of the tip is covered with the reflective film, so that the emission angle of fluorescence from the tip of the columnar crystal is It is suppressed from becoming large, and the possibility that the fluorescence emitted from the tip of the columnar crystal is incident on a surrounding photoelectric conversion element different from the photoelectric conversion element facing the columnar crystal is reduced, and the sharpness of the image Will improve.

It is a figure which shows typically the structure of an example of the radiographic image detection apparatus for describing embodiment of this invention. It is a figure which shows typically the structure of the sensor panel of the radiographic image detection apparatus of FIG. It is a figure which shows typically the structure of the radiographic image conversion panel of the radiographic image detection apparatus of FIG. It is a figure which shows the IV-IV cross section of the fluorescent substance of the radiographic image conversion panel of FIG. It is a figure which shows the VV cross section of the fluorescent substance of the radiographic image conversion panel of FIG. The figure which shows typically the fluorescence radiate | emitted from the fluorescent substance of the radiographic image conversion panel of FIG. The figure which shows an example of the manufacturing method of the radiographic image conversion panel of FIG. The figure which shows the modification of the radiographic image conversion panel of FIG.

  FIG. 1 shows a configuration of an example of a radiographic image detection apparatus for explaining an embodiment of the present invention, and FIG. 2 shows a configuration of a sensor panel of the radiographic image detection apparatus of FIG.

  The radiation image detection apparatus 1 includes a radiation image conversion panel 2 having a scintillator (phosphor) 18 that emits fluorescence by radiation exposure, and a two-dimensional array of photoelectric conversion elements 26 that photoelectrically convert the fluorescence of the scintillator 18 of the radiation image conversion panel 2. A sensor panel 3.

  The radiation image conversion panel 2 has a support 11, and the scintillator 18 is formed on the support 11. The radiation image conversion panel 2 is configured separately from the sensor panel 3, the surface of the scintillator 18 on the side opposite to the support 11 is opposed to the two-dimensional array of photoelectric conversion elements 26 of the sensor panel 3, and the scintillator 18 and photoelectric conversion are performed. It is bonded to the sensor panel 3 through a resin layer that optically couples the element 26.

  The radiological image detection apparatus 1 of this example is an ISS type radiological image detection apparatus, and the radiation is irradiated from the sensor panel 3 side, passes through the sensor panel 3 and enters the scintillator 18. Fluorescence is generated in the scintillator 18 where the radiation is incident, and the generated fluorescence is photoelectrically converted by the photoelectric conversion element 26 of the sensor panel 3. In the radiation image detection apparatus 1 configured as described above, the radiation incident side of the scintillator 18 that generates a large amount of fluorescence is provided adjacent to the photoelectric conversion element 26, so that sensitivity is improved.

  The sensor panel 3 includes a TFT substrate 16 in which a switch element 28 made of a thin film transistor (TFT) is formed on an insulating substrate, and a two-dimensional array of photoelectric conversion elements 26 is formed on the TFT substrate 16. Yes. A flattening layer 23 is formed on the TFT substrate 16 so as to cover these photoelectric conversion elements 26 and to flatten the surface of the TFT substrate 16. An adhesive layer 25 for bonding the radiation image conversion panel 2 and the sensor panel 3 is formed on the planarizing layer 23. The planarizing layer 23 and the adhesive layer 25 form the above resin layer. As the resin layer, a matching oil made of a transparent liquid or gel can also be used. The thickness of the resin layer is preferably 50 μm or less, more preferably 5 μm to 30 μm, from the viewpoints of sensitivity and image sharpness.

  Each photoelectric conversion element 26 includes a photoconductive layer 20 that generates charges when the fluorescence of the scintillator 18 is incident, and a pair of electrodes provided on the front and back surfaces of the photoconductive layer 20. The electrode 22 provided on the surface of the photoconductive layer 20 on the scintillator layer 18 side is a bias electrode for applying a bias voltage to the photoconductive layer 20, and the electrode 24 provided on the opposite surface is a photoconductive layer. A charge collection electrode that collects the charge generated in the layer 20.

  The switch elements 28 are two-dimensionally arranged on the TFT substrate 16 corresponding to the two-dimensional arrangement of the photoelectric conversion elements 26, and the charge collecting electrodes 24 of the respective photoelectric conversion elements 26 correspond to the corresponding switch elements 28 of the TFT substrate 16. It is connected to the. The charges collected by each charge collecting electrode 24 are read out via the switch element 28.

  The TFT substrate 16 is extended in one direction (row direction), a plurality of gate lines 30 for turning on / off each switch element 28, and a direction orthogonal to the gate lines 30 (column direction). A plurality of signal lines (data lines) 32 for reading out charges through the switch element 28 in the on state are provided. A connection terminal 38 to which individual gate lines 30 and individual signal lines 32 are connected is disposed on the peripheral edge of the TFT substrate 16. As shown in FIG. 2, the connection terminal 38 is connected to a circuit board (not shown) via a connection circuit 39. The circuit board includes a gate line driver as an external circuit and a signal processing unit.

  Each switch element 28 is sequentially turned on in units of rows by a signal supplied from the gate line driver via the gate line 30. Then, the charge read by the switch element 28 in the on state is transmitted through the signal line 32 as a charge signal and input to the signal processing unit. As a result, the electric charges are sequentially read out in units of rows, converted into electric signals by the signal processing unit, and digital image data is generated.

  Hereinafter, the radiation image conversion panel 2 and the scintillator 18 will be described in detail.

  FIG. 3 schematically shows the configuration of the radiation image conversion panel 2.

  The radiation image conversion panel 2 includes a support 11 and a scintillator 18 formed on the support 11.

  As the support 11, a carbon plate, CFRP (carbon fiber reinforced plastic), a glass plate, a quartz substrate, a sapphire substrate, a metal sheet selected from iron, tin, chromium, aluminum, and the like can be used. It is not limited to the above as long as the scintillator 18 can be formed thereon.

  As the fluorescent material forming the scintillator 18, for example, CsI: Tl, NaI: Tl (thallium activated sodium iodide), CsI: Na (sodium activated cesium iodide), and the like can be used. CsI: Tl is preferable because it is compatible with the maximum spectral sensitivity of the a-Si photodiode (around 550 nm).

  The scintillator 18 includes a columnar portion 34 provided on the side opposite to the support 11 and a non-columnar portion 36 provided on the support 11 side. Although the columnar part 34 and the non-columnar part 36 will be described in detail later, the columnar part 34 and the non-columnar part 36 are continuously formed in a layered manner on the support 11 by a vapor deposition method. In addition, although the columnar part 34 and the non-columnar part 36 are formed with the same fluorescent substance, the addition amount of activators, such as Tl, may differ.

  The columnar portion 34 is formed by a group of columnar crystals 35 formed by growing the crystal of the fluorescent material in a columnar shape. A space is placed between adjacent columnar crystals 35, and the columnar crystals 35 exist independently of each other.

  The non-columnar portion 36 is formed by a group of crystals in which the fluorescent substance crystal is relatively small. In the non-columnar portion 36, crystals are irregularly bonded or overlapped with each other, so that a clear void is not easily generated between the crystals. Note that the non-columnar portion 36 may include an amorphous body of the fluorescent material.

  The scintillator 18 formed on the support 11 is covered with a protective film 19 having moisture resistance. The scintillator 18 is sealed by the support 11 and the protective film 19, and deterioration due to moisture absorption is suppressed.

  As the protective film 19, for example, parylene can be used. Parylene can easily form a thin film on the entire surface of the scintillator 18 by vapor deposition. Moreover, a polyethylene terephthalate (PET) film etc. can also be used as a protective film.

  The radiation image conversion panel 2 is configured so that the surface of the scintillator 18 opposite to the support 11, that is, the tip of each columnar crystal of the columnar portion 34 faces the two-dimensional array of photoelectric conversion elements 26 of the sensor panel 3. Are pasted together. Accordingly, a columnar portion 34 made of a group of columnar crystals 35 is disposed on the radiation incident side of the scintillator 18.

  The fluorescence generated in the columnar crystal 35 of the columnar part 34 is suppressed from being diffused by repeating total reflection in the columnar crystal 35 due to the difference in refractive index between the columnar crystal 35 and the surrounding gap (air). The columnar crystal 35 is guided to the opposing photoelectric conversion element 26. Thereby, the sharpness of the image is improved.

  Of the fluorescence generated in the columnar crystal 35 of the columnar portion 34, the fluorescence directed to the side opposite to the sensor panel 3, that is, toward the support 11, is reflected toward the sensor panel 3 side in the non-columnar portion 36. . Thereby, the utilization efficiency of fluorescence increases and the sensitivity improves.

  Further, the columnar crystal 35 of the columnar portion 34 is relatively thin in the initial stage of growth, and becomes thicker as the crystal grows. In the joint portion between the columnar portion 34 and the non-columnar portion 36, small-diameter columnar crystals 35 stand, and a large number of relatively large voids extend in the crystal growth direction, and the porosity is large. One non-columnar portion 36 is formed by a small-diameter spherical crystal 37 or an aggregate thereof, and the individual voids are relatively small, denser than the columnar portion 34, and have a small porosity. By interposing the non-columnar portion 36 between the support 11 and the columnar portion 34, the adhesion between the support 11 and the scintillator 18 is improved. As a result, resistance to stress acting due to warpage or impact caused by the difference in linear expansion between the support 11 and the TFT substrate 16 of the sensor panel 3 is improved, and the scintillator 18 is prevented from peeling off from the support 11. .

  FIG. 4 is an electron micrograph showing the IV-IV cross section of the scintillator 18 in FIG.

  As apparent from FIG. 4, in the columnar portion 34, the columnar crystal 35 has a substantially uniform cross-sectional diameter with respect to the crystal growth direction, has a gap around the columnar crystal 35, and the columnar crystals 35 are mutually connected. It turns out that it exists independently. The crystal diameter (column diameter) of the columnar crystal 35 is preferably 2 μm or more and 8 μm or less from the viewpoints of the light guide effect, mechanical strength, and pixel defect prevention. If the column diameter is too small, the mechanical strength of the columnar crystal 35 is insufficient and there is a concern of damage due to impact or the like. If the column diameter is too large, the number of columnar crystals 35 for each photoelectric conversion element 26 decreases, and the crystal There is a concern that the probability of the element becoming defective when a crack occurs is increased. Although depending on the size of the photoelectric conversion element 26, the number of columnar crystals for each photoelectric conversion element 26 is typically several tens to several hundreds.

  Here, the column diameter indicates the maximum diameter of the crystal observed from the upper surface in the growth direction of the columnar crystal 35. As a specific measuring method, the column diameter is measured by observing with an SEM (scanning electron microscope) from the upper surface in the growth direction of the columnar crystal 35. Observation is performed at a magnification (about 2000 times) at which 100 to 200 columnar crystals 35 can be observed, and a maximum value of the column diameter is measured and averaged for all the crystals included in one image. The column diameter (μm) is read to 2 digits after the decimal point, and the average value is a value obtained by rounding the second digit after the decimal point in accordance with JIS Z 8401.

  FIG. 5 is an electron micrograph showing the VV cross section of the scintillator 18 in FIG.

  As apparent from FIG. 5, in the non-columnar portion 36, crystals are irregularly coupled or overlapped, and a clear gap between the crystals is not recognized as much as the columnar portion 34. The diameter of the crystal forming the non-columnar portion 36 is preferably 0.5 μm or more and 7.0 μm or less from the viewpoint of adhesion and light reflection. If the crystal diameter is too small, there is a concern that the gap approaches 0 and the function of light reflection decreases, and if the crystal diameter is too large, the flatness decreases and the adhesion to the support 11 may decrease. . Further, the shape of the crystal forming the non-columnar portion 36 is preferably substantially spherical from the viewpoint of light reflection.

  Here, the measurement of the crystal diameter in the case where the crystals are bonded is considered as a boundary between the crystals by connecting the dents (concaves) generated between adjacent crystals, and the bonded crystals are defined as the minimum polygon. Then, the column diameter and the crystal diameter corresponding to the column diameter were measured, and the average value was taken in the same manner as the crystal diameter in the columnar portion 34, and the value was adopted.

  Regarding the thickness of the columnar portion 34 and the non-columnar portion 36, when the thickness of the columnar portion 34 is t1, and the thickness of the non-columnar portion 36 is t2, (t2 / t1) is 0.01 or more and 0.25 or less. Is more preferable, and 0.02 or more and 0.1 or less are more preferable. When (t2 / t1) is in the above range, the fluorescence efficiency, the light diffusion prevention, and the light reflection become suitable ranges, and the sensitivity and the sharpness of the image are improved.

  The thickness t1 of the columnar portion 34 is preferably 200 μm or more and 700 μm or less from the viewpoint of sufficient radiation absorption in the columnar portion 34 and image sharpness, although it depends on the energy of radiation. If the thickness of the columnar portion 34 is too small, the radiation cannot be sufficiently absorbed and the sensitivity may be lowered. If the thickness is too large, light diffusion occurs, and the sharpness of the image is also caused by the light guide effect of the columnar crystal. There is a concern that the degree will decrease.

  The thickness t2 of the non-columnar portion 36 is preferably 5 μm or more and 125 μm or less from the viewpoint of adhesion to the support 11 and light reflection. If the thickness of the non-columnar portion 36 is too small, sufficient adhesion to the support 11 may not be obtained. If the thickness is too large, the contribution of fluorescence in the non-columnar portion 36 and the non-columnar portion 36 There is a concern that diffusion due to light reflection increases and the sharpness of the image decreases.

  FIG. 6 shows the fluorescence emitted from the tip of the columnar crystal 35. In FIG. 6, the tip of the columnar crystal 35 is tapered (FIG. 6A), and the tip is flat (FIG. 6B) for comparison. ).

  The tip portion 35A of the columnar crystal 35 is formed in a tapered shape. The side surface of the columnar crystal 35 is covered with a reflective film 40 having reflectivity with respect to the fluorescence generated in the scintillator 18. On the side surface of the columnar crystal 35, the reflection film 40 extends from the tip to the base end side beyond the tapered portion. Note that the distal end surface of the distal end portion 35 </ b> A is exposed without being covered by the reflective film 40.

  As the reflection film 40, for example, a metal reflection film such as aluminum or an aluminum alloy can be used. Examples of the aluminum alloy include an aluminum alloy containing an element selected from Mg, Cr, Zr, Ti, and Mn. CsI used as a fluorescent material forming the scintillator 18 has deliquescence as described above. When deliquescence occurs, halogen (I: iodine) in CsI may diffuse and corrode aluminum. The above aluminum alloy is excellent in corrosion resistance and can maintain reflection performance.

  A protective film 19 and an adhesive layer 25 are interposed between the scintillator 18 and the sensor panel 3, and the fluorescence emitted from the tip surface of the columnar crystal 35 depends on the emission angle of the surface of the sensor panel 3. It is shifted in the direction and enters the sensor panel 3. When the tip 35A of the columnar crystal 35 is formed in a tapered shape, the emission angle φ1 of the fluorescence from the tip of the columnar crystal 35 (see FIG. 6A) and the tip of the columnar crystal are formed flat. In comparison with the emission angle φ2 of the fluorescence from the tip of the columnar crystal (see FIG. 6B), the emission angle φ1 in the former case tends to be small, and the deviation in the surface direction of the sensor panel 3 is It is suppressed. Fluorescence emitted from the tip of the columnar crystal 35 having the tip 35A formed in a tapered shape can be incident on a peripheral photoelectric conversion element 26 other than the photoelectric conversion element 26 facing the columnar crystal 35. And the sharpness of the image is improved. In particular, when the radiation image conversion panel 2 and the sensor panel 3 are bonded to each other with the adhesive layer 25 interposed between the scintillator 18 and the sensor panel 3, the distance between the scintillator 18 and the sensor panel 3 is the adhesive layer. Accordingly, the displacement increases until it enters the sensor panel 3, so that the tip 35 </ b> A of the columnar crystal 35 is formed in a tapered shape, and the side surface of the tip 35 </ b> A is formed on the reflective film. Coating with 40 is useful.

  Next, an example of a method for manufacturing the scintillator 18 will be described with reference to FIG. Hereinafter, a case where CsI: Tl is used as the fluorescent material will be described as an example.

  The scintillator 18 is directly formed on the surface of the support 11 by a vapor deposition method. According to the vapor deposition method, the non-columnar portion 36 and the columnar portion 34 can be formed continuously and integrally in this order. In an environment with a degree of vacuum of 0.01 to 10 Pa, CsI: Tl is heated and vaporized by means such as energizing a resistance heating crucible, and the temperature of the support 11 is set to room temperature (20 ° C.) to 300 ° C. : Tl is deposited on the support 11.

  When the CsI: Tl crystal phase is formed on the support 11, initially a spherical crystal having a relatively small diameter is deposited to form the non-columnar portion 36 (FIG. 7A). Then, at least one of the conditions of the degree of vacuum and the temperature of the support 11 is changed, and the columnar portion 34 is formed continuously after the non-columnar portion 36 is formed. Specifically, the columnar crystal 35 is grown by increasing the degree of vacuum and / or increasing the temperature of the support 11 (FIG. 7B).

  At the end of the step of growing the columnar crystal 35, the tip portion 35 </ b> A of the columnar crystal 35 is formed in a tapered shape by controlling the temperature of the support 11. When the temperature of the support 11 is 110 ° C., the angle of the tip of the columnar crystal 35 is about 170 °, 140 ° C., about 60 °, 200 ° C., about 70 °, 260 ° C. It is known to be about 120 degrees (see Patent Document 2).

  Next, a reflective film 40 made of aluminum is formed on the surface of the tip portion 35A of the columnar crystal 35 (FIG. 7C). As a film forming method, a vacuum deposition method, a sputtering method, or the like can be used. Here, the gap between the columnar crystals is very narrow, typically several μm or less, but by forming the tip portion 35A of the columnar crystal 35 in a tapered shape, the gap between the columnar crystals is widened, and the reflection film 40 can be formed to a depth between columnar crystals. Thereby, the light guide effect of the columnar crystal 35 can be enhanced. In addition, the aluminum reflective film 40 has moisture resistance, and the moisture resistance of the columnar crystal 35 covered thereby can also be improved. In order to form the reflective film 40 to the deep part between the columnar crystals, the tip part 35A of the columnar crystal 35 is preferably formed in a tapered shape with an angle of the tip of less than 90.

  As a method for forming the reflective film 40, a vacuum deposition method or a sputtering method can be used as described above, but a sputtering method is preferably used. If the film formation rate is too high, the gap between the columnar crystals closes in the vicinity of the tip, and there is a concern that the reflective film 40 cannot be formed to the deep part of the gap. In this respect, it is preferable to use a sputtering method having a relatively low film formation rate. In addition, since the thermal expansion coefficient of CsI is 40 PPM and the thermal expansion coefficient of Al is 30 PPM, both are relatively high, and therefore, the adhesive force of the reflective film 40 to the columnar crystal 35 is also important. Since the sputtering method can form a film having higher kinetic energy of target atoms (molecules) and better adhesion than the vacuum deposition method, it is preferable to use the sputtering method also in this respect.

  Next, a part of the tip side of the tip portion 35A of the columnar crystal 35 is removed by a chemical mechanical polishing method or the like, and the reflection film 40 covering the tip is also removed to expose the tip surface of the tip portion 35A ( Fig. 7D). Here, what is removed at the front end portion 35A of the columnar crystal 35 is a part on the front end side, and the front end portion 35A maintains a tapered shape even after this is removed.

  Next, a protective film 19 made of parylene is formed on the entire surface of the scintillator 18 by vapor deposition (FIG. 7E). Here, by forming the tip portion 35A of the columnar crystal 35 in a tapered shape, the gap between the columnar crystals is widened, and the protective film 19 can be formed up to the deep portion of the gap between the columnar crystals. Thereby, the moisture resistance of the columnar crystal 35 can be increased. Further, the tapered tip portion 35A is slightly disadvantageous in terms of strength compared to a flat one, but the tip portion 35A is formed by forming the reflective film 40 and the protective film 19 to the deep part of the gap between the columnar crystals. The columnar crystal 35 can be reinforced and the strength thereof can be increased, thereby preventing the tip 35A of the columnar crystal 35 from being damaged when the radiation image conversion panel 2 and the sensor panel 3 are bonded together. You can also. Note that the gap between the columnar crystals is narrowed by the reflective film 40, and the protective film 19 extends only to the depth position on the tip side of the reflective film 40. In other words, the reflective film 40 extends to the base end side of the columnar crystal 35 rather than the protective film 19. Thereby, the protective film 19 does not directly contact the side surface of the columnar crystal 35, and the light guide effect of the columnar crystal 35 is prevented from being lowered.

  As described above, the scintillator 18 can be manufactured efficiently and easily. Further, according to this manufacturing method, there is an advantage that scintillators of various specifications can be easily manufactured as designed by controlling the degree of vacuum and the support temperature in film formation of the scintillator 18.

  As described above, the tip portion 35A of the columnar crystal 35 is tapered and narrowed, and the side surface of the tip portion 35A is covered with the reflective film 40. The emission angle of the fluorescent light is suppressed from increasing, and the fluorescent light emitted from the tip of the columnar crystal 35 is incident on the surrounding photoelectric conversion element 26 different from the photoelectric conversion element 26 facing the columnar crystal 35. The possibility is reduced and the sharpness of the image is improved.

  In the radiological image detection apparatus 1 described above, only the tip portion 35A of the columnar crystal 35 is formed in a tapered shape. However, as shown in FIG. 8, from the tip of the columnar crystal 35 to the approximate center in the growth direction. The portion may be formed in a tapered shape (FIG. 8A), or the entire columnar crystal 35 may be formed in a tapered shape (FIG. 8B). As the taper shape extends to the base end side of the columnar crystal 35, the gap between the columnar crystals widens, and the reflective film 40 and the protective film 19 can be formed to the deep part of the gap. However, if the entire columnar crystal 35 has a tapered shape, there is a concern that the amount of light emission will be insufficient, and the portion from the tip of the columnar crystal 35 to the approximate center in the growth direction is preferably tapered.

  In the radiological image detection apparatus 1 described above, the radiographic image conversion panel 2 and the sensor panel 3 are bonded to each other via the adhesive layer 25 between the scintillator 18 and the sensor panel 3. There is no particular limitation on the method of bonding the sensor panel 3 and the sensor panel 3, and the scintillator 18 of the radiation image conversion panel 2 and the group of photoelectric conversion elements 26 of the sensor panel 3 may be optically coupled. 3 can also be used.

  In the radiation image detection device 1 described above, the radiation is incident from the sensor panel 3 side. However, a configuration in which the radiation is incident from the radiation image conversion panel 2 side may be employed.

  The above-described radiographic image detection apparatus can detect a radiographic image with high sensitivity and high definition, and is therefore required to detect a sharp image with a low radiation dose, such as an X-ray imaging apparatus for medical diagnosis such as mammography. It can be used by incorporating it into various devices. For example, it can be used for nondestructive inspection as an industrial X-ray imaging apparatus, or can be used as a detection apparatus for particle beams (α rays, β rays, γ rays) other than electromagnetic waves, and its application range is wide. .

  Hereinafter, materials that can be used for each element constituting the sensor panel 3 will be described.

[Photoelectric conversion element]
As the photoconductive layer 20 (see FIG. 1) of the photoelectric conversion element 26 described above, an inorganic semiconductor material such as amorphous silicon is often used. For example, the organic photoelectric conversion described in Japanese Patent Application Laid-Open No. 2009-32854 is used. (OPC: Organic photoelectric conversion) material can also be used. A film formed of this OPC material (hereinafter referred to as an OPC film) can be used as the photoconductive layer 20. The OPC film includes an organic photoelectric conversion material, absorbs light emitted from the phosphor layer, and generates a charge corresponding to the absorbed light. Thus, if the OPC film includes an organic photoelectric conversion material, the OPC film has a sharp absorption spectrum in the visible region, and hardly absorbs electromagnetic waves other than light emission by the phosphor layer, and radiation such as X-rays. Can be effectively suppressed as a result of being absorbed by the OPC film.

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

  Examples of the organic photoelectric conversion material that can satisfy such conditions include arylidene organic compounds, quinacridone organic compounds, and phthalocyanine organic compounds. For example, since the absorption peak wavelength in the visible region of quinacridone is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI (Tl) is used as the material of the phosphor layer, the difference in the peak wavelength may be within 5 nm. This makes it possible to maximize the amount of charge generated in the OPC film.

  At least a part of the organic layer provided between the bias electrode 22 and the charge collection electrode 24 can be formed of an OPC film. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact improvement. It can be formed by stacking or mixing parts.

  The organic layer preferably contains an organic p-type compound or an organic n-type compound. The organic p-type semiconductor (compound) is a donor organic semiconductor (compound) mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound. For example, triarylamine compound, benzidine compound, pyrazoline compound, styrylamine compound, hydrazone compound, triphenylmethane compound, carbazole compound, polysilane compound, thiophene compound, phthalocyanine compound, cyanine compound, merocyanine compound, oxonol compound, polyamine compound, indole Compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), nitrogen-containing heterocyclic compounds The metal complex etc. which it has as can be used. In addition, it is not restricted to these, If it is an organic compound whose ionization potential is smaller than the organic compound used as an n-type (acceptor property) compound, it can use as a donor organic semiconductor.

  An organic n-type semiconductor (compound) is an acceptor organic semiconductor (compound) mainly represented by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound. For example, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), 5- to 7-membered heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms (E.g. pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole, Benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazaindene, o Metal complexes having as ligands such as saziazole, imidazopyridine, pyralidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine), polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silyl compounds, nitrogen-containing heterocyclic compounds Etc. In addition, not only these but an organic compound with an electron affinity larger than the organic compound used as a donor organic compound can be used as an acceptor organic semiconductor.

  As the p-type organic dye or the n-type organic dye, known ones can be used, but preferably a cyanine dye, a styryl dye, a hemicyanine dye, a merocyanine dye (including zero methine merocyanine (simple merocyanine)), three nuclei Merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye, complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azamethine dye, coumarin dye, arylidene dye, anthraquinone dye, triphenyl Methane dye, azo dye, azomethine dye, spiro compound, metallocene dye, fluorenone dye, fulgide dye, perylene dye, phenazine dye, phenothiazine dye, quinone dye, in Pigment dye, diphenylmethane dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, phenoxazine dye, phthaloperylene dye, porphyrin dye, chlorophyll dye, phthalocyanine dye, metal complex dye, condensed aromatic carbocyclic system And dyes (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives) and the like.

  Between the pair of electrodes, a p-type semiconductor layer and an n-type semiconductor layer are provided, at least one of the p-type semiconductor and the n-type semiconductor is an organic semiconductor, and the semiconductor layer includes A photoelectric conversion film (photosensitive layer) having a bulk heterojunction structure layer including a p-type semiconductor and an n-type semiconductor as an intermediate layer can be preferably used. Thus, in the photoelectric conversion film, the inclusion of the bulk heterojunction structure layer can compensate for the disadvantage that the carrier diffusion length of the organic layer is short, and can improve the photoelectric conversion efficiency. The bulk heterojunction structure is described in detail in Japanese Patent Application Laid-Open No. 2005-303266.

The thickness of the photoelectric conversion film is preferably as large as possible in terms of absorbing light from the phosphor layer. However, considering the ratio that does not contribute to charge separation, it is preferably 30 nm to 300 nm, and more preferably 50 nm to 250 nm. Hereinafter, it is particularly preferably 80 nm or more and 200 nm or less.
For other configurations relating to the OPC film described above, for example, the description in JP-A-2009-32854 is helpful.

[Switch element]
As the active layer of the switch element 28, an inorganic semiconductor material such as amorphous silicon is often used, but an organic material can be used as described in, for example, Japanese Patent Application Laid-Open No. 2009-212389. The organic TFT may have any type of structure, but the most preferred is a field effect transistor (FET) structure. In this FET structure, a gate electrode is provided on a part of the upper surface of an insulating substrate, and further, an insulating layer is provided so as to cover the electrode and to be in contact with the substrate at a portion other than the electrode. Further, a semiconductor active layer is provided on the upper surface of the insulator layer, and the transparent source electrode and the transparent drain electrode are separately arranged on a part of the upper surface. Although this configuration is called a top contact type element, a bottom contact type element in which a source electrode and a drain electrode are located below the semiconductor active layer can also be preferably used. Alternatively, a vertical transistor structure in which carriers flow in the film thickness direction of the organic semiconductor film may be used.

(Active layer)
The organic semiconductor material referred to here is an organic material exhibiting the characteristics of a semiconductor, and similarly to a semiconductor made of an inorganic material, a p-type organic semiconductor material that conducts holes as carriers (or simply p-type). And an n-type organic semiconductor material that conducts electrons as carriers (or simply referred to as an n-type material or an electron transport material). In general, many organic semiconductor materials exhibit better characteristics than p-type materials, and generally, p-type transistors are also superior in terms of transistor operation stability in the atmosphere. The material will be described.

One of the characteristics of the organic thin film transistor is carrier mobility (also simply referred to as mobility) μ indicating the mobility of carriers in the organic semiconductor layer. Although it depends on the application, in general, the mobility should be high, preferably 1.0 × 10 ⁻⁷ cm ² / Vs or more, and more preferably 1.0 × 10 ⁻⁶ cm ² / Vs or more. Preferably, it is 1.0 × 10 ⁻⁵ cm ² / Vs or more. The mobility can be obtained by characteristics when a field effect transistor (FET) element is manufactured or by a time-of-flight measurement (TOF) method.

  The p-type organic semiconductor material may be a low molecular material or a high molecular material, but is preferably a low molecular material. Low molecular weight materials can be easily purified because various purification methods such as sublimation purification, recrystallization, column chromatography, etc. can be applied. Many have high characteristics for reasons such as these. The molecular weight of the low molecular weight material is preferably 100 or more and 5000 or less, more preferably 150 or more and 3000 or less, and still more preferably 200 or more and 2000 or less.

  As such a p-type organic semiconductor material, a phthalocyanine compound or a naphthalocyanine compound can be exemplified, and specific examples are shown below. M represents a metal atom, Bu represents a butyl group, Pr represents a propyl group, Et represents an ethyl group, and Ph represents a phenyl group.

(Constituent elements of switch elements other than the active layer)
The material constituting the gate electrode, the source electrode, or the drain electrode is not particularly limited as long as it has necessary conductivity. For example, ITO (indium doped tin oxide), IZO (indium doped zinc oxide), Transparent conductive oxides such as SnO ₂ , ATO (antimony-doped tin oxide), ZnO, AZO (aluminum-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO ₂ , FTO (fluorine-doped tin oxide), PEDOT / PSS Examples thereof include transparent conductive polymers such as (poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid) and carbon materials such as carbon nanotubes. These electrode materials can be formed by a method such as a vacuum deposition method, a sputtering method, or a solution coating method.

The material used for the insulating layer is not particularly limited as long as it has a necessary insulating effect. For example, inorganic materials such as silicon dioxide, silicon nitride, and alumina, polyester (PEN (polyethylene naphthalate), PET ( Polyethylene terephthalate)), polycarbonate, polyimide, polyamide, polyacrylate, epoxy resin, polyparaxylylene resin, novolac resin, PVA (polyvinyl alcohol), PS (polystyrene), and the like. These insulating film materials can be formed by a method such as vacuum deposition, sputtering, or solution coating.
For other configurations related to the organic TFT described above, for example, the description in JP-A-2009-212389 is helpful.

  For the active layer of the switch element 28, for example, an amorphous oxide described in JP 2010-186860 can also be used. Here, an active layer containing an amorphous oxide included in a field effect transistor described in Japanese Patent Application Laid-Open No. 2010-186860 will be described. This active layer functions as a channel layer of a field effect transistor in which electrons or holes move.

  The active layer is configured to include an amorphous oxide semiconductor. Since the amorphous oxide semiconductor can be formed at a low temperature, it is preferably formed over a flexible substrate. The amorphous oxide semiconductor used for the active layer is preferably an amorphous oxide containing at least one element selected from the group consisting of In, Sn, Zn, or Cd, more preferably In. An amorphous oxide containing at least one selected from the group consisting of Sn and Zn, more preferably an amorphous oxide containing at least one selected from the group consisting of In and Zn.

Specific examples of the amorphous oxide used for the active layer include In ₂ O ₃ , ZnO, SnO ₂ , CdO, Indium-Zinc-Oxide (IZO), Indium-Tin-Oxide (ITO), Gallium- Zinc-Oxide (GZO), Indium-Gallium-Oxide (IGO), and Indium-Gallium-Zinc-Oxide (IGZO) are mentioned.

  As a method for forming the active layer, it is preferable to use a vapor phase film forming method with a polycrystalline sintered body of an oxide semiconductor as a target. Among vapor deposition methods, sputtering and pulsed laser deposition (PLD) are suitable. Furthermore, the sputtering method is preferable from the viewpoint of mass productivity. For example, the film is formed by controlling the degree of vacuum and the oxygen flow rate by RF magnetron sputtering deposition.

  The formed active layer is confirmed to be an amorphous film by a well-known X-ray diffraction method. The composition ratio of the active layer is determined by RBS (Rutherford backscattering) analysis.

The electrical conductivity of the active layer is preferably 10 ⁻⁴ Scm ⁻¹ or more and less than 10 ² Scm ⁻¹ , more preferably 10 ⁻¹ Scm ⁻¹ or more and less than 10 ² Scm ⁻¹ . Examples of the method for adjusting the electrical conductivity of the active layer include a known adjustment method using oxygen vacancies, an adjustment method using a composition ratio, an adjustment method using impurities, and an adjustment method using an oxide semiconductor material.
For other configurations relating to the above-described amorphous oxide, for example, the description in Japanese Patent Application Laid-Open No. 2010-186860 is helpful.

[Insulating substrate]
Examples of the insulating substrate 12 include glass, quartz, and plastic film. Examples of plastic films include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose triacetate. Examples thereof include films made of (TAC), cellulose acetate propionate (CAP) and the like. Further, these plastic films may contain an organic or inorganic filler. In addition, a flexible substrate formed using aramid, bionanofiber, or the like that is flexible, has low thermal expansion, and high strength, and has characteristics that cannot be obtained with existing glass or plastic, can be suitably used.

(Aramid)
The aramid material has high heat resistance with a glass transition temperature of 315 ° C., high rigidity with Young's modulus of 10 GPa, and high dimensional stability with a thermal expansion coefficient of −3 to 5 ppm / ° C. For this reason, when an aramid film is used, it is possible to easily form a high-quality film of a semiconductor layer as compared with a case where a general resin film is used. In addition, the high heat resistance of the aramid material allows the electrode material to be cured at a high temperature to reduce resistance. Furthermore, it can cope with automatic mounting of IC including a solder reflow process. Furthermore, since the thermal expansion coefficient is close to that of ITO (indium tin oxide), gas / barrier film, and glass substrate, there is little warpage after production. And hard to break. Here, it is preferable to use an aramid material that does not contain halogen and is halogen-free (conforming to JPCA-ES01-2003). The aramid film may be laminated with a glass substrate or a PET substrate, or may be attached to a device casing.

  Suitable for aramid materials that can be easily formed into colorless and transparent films by solving low solubility in solvents due to the high cohesion (hydrogen bonding) between molecules of aramid by molecular design. Can be used. The molecular design that controls the order of the monomer units and the type and position of the substituents on the aromatic ring maintains the linear molecular structure with high linearity that leads to high rigidity and dimensional stability of the aramid material, while maintaining solubility. Good moldability is obtained. This molecular design can also be halogen-free.

  Moreover, it can use suitably also about the aramid material in which the characteristic of the in-plane direction of the film was optimized. By controlling the tension condition for each step of solution casting, longitudinal stretching, and transverse stretching according to the strength of the aramid film that changes sequentially during molding, it has a highly linear rod-like molecular structure and anisotropy in physical properties. The in-plane characteristics of the aramid film that tends to occur can be balanced.

  Specifically, in the solution casting process, the physical properties in the in-plane thickness direction are controlled by controlling the drying rate of the solvent, and the strength of the film containing the solvent and the peel strength from the cast drum are optimized. . In the longitudinal stretching step, stretching conditions according to the strength of the film, which changes sequentially during stretching, and the residual amount of solvent are precisely controlled. In the transverse stretching step, the transverse stretching conditions are controlled in accordance with changes in the film strength that change due to heating, and the transverse stretching conditions for relaxing the residual stress of the film are controlled. Use of such an aramid material can solve the problem that the aramid film after molding is curled.

  In any of the above devices for ease of forming and the device for balancing the characteristics in the in-plane direction of the film, since the rod-like molecular structure with high linearity unique to aramid is maintained, the thermal expansion coefficient can be kept low. It is also possible to further reduce the thermal expansion coefficient by changing the stretching conditions during film formation.

(Bionanofiber)
A nanofiber can be used as a reinforcement of a transparent and flexible resin material because a component sufficiently small with respect to the wavelength of light does not cause light scattering. Among nanofibers, cellulose microfibril bundles produced by bacteria (Acetobacter Xylinum) have a width of 50 nm, a size of about 1/10 of the visible light wavelength, and high strength, high elasticity, and low heat. It has a characteristic of being swollen, and a composite material of this bacterial cellulose and a transparent resin (sometimes referred to as bionanofiber) can be suitably used.

Transparent Bionano that shows light transmittance of about 90% at a wavelength of 500 nm while impregnating and curing transparent resin such as acrylic resin and epoxy resin on bacterial cellulose sheet and containing fiber at a high ratio of about 60-70% Fiber is obtained. This bionanofiber provides a low thermal expansion coefficient (about 3 to 7 ppm) comparable to that of silicon crystals, steel-like strength (about 460 MPa), and high elasticity (about 30 GPa).
For the configuration relating to the above-described bio-nanofiber, for example, the description in JP-A-2008-34556 is helpful.

[Planarization layer and adhesive layer]
The planarizing layer 23 and the adhesive layer 25 as a resin layer for optically coupling the scintillator 18 and the photoelectric conversion element 26 are particularly those that can reach the photoelectric conversion element 26 without attenuating the fluorescence of the scintillator 18. There is no limit. As the planarizing layer 23, a resin such as polyimide or parylene can be used, and it is preferable to use a polyimide having good film forming properties. Examples of the adhesive layer 25 include thermoplastic resins, UV curable adhesives, heat curable adhesives, room temperature curable adhesives, double-sided adhesive sheets, and the like, from the viewpoint of not reducing the sharpness of an image. It is preferable to use an adhesive made of a low-viscosity epoxy resin that can form a sufficiently thin adhesive layer with respect to the element size.

  As described above, the following (1) to (6) radiation image conversion panels are disclosed in the present specification.

(1) A radiation image conversion panel including a phosphor containing a phosphor that emits fluorescence by radiation exposure, wherein the phosphor includes a group of columnar crystals formed by growing crystals of the phosphor in a columnar shape, Each columnar crystal is a radiation image conversion panel in which at least a tip portion is formed in a taper shape, and at least a side surface of the tip portion of the columnar crystal is covered with a reflective film.
(2) The radiation image conversion panel according to (1), further including a protective film that covers the phosphor, wherein the protective film is inserted between tip portions of the group of columnar crystals. .
(3) The radiation image conversion panel according to (2), wherein the reflection film extends to a proximal end side of the columnar crystal rather than a protective film entering between the distal end portions of the group of columnar crystals. Image conversion panel.
(4) The radiation image conversion panel according to any one of (1) to (3), wherein the reflection film is a metal reflection film.
(5) The radiation image conversion panel according to (4), wherein the metal reflection film is a film of aluminum or an aluminum alloy.
(6) The radiation image conversion panel according to any one of (1) to (5), wherein an angle of a tip of each columnar crystal is less than 90 degrees.

  Further, in the present specification, the following radiation image detection devices (7) to (10) are disclosed.

(7) The radiation image conversion panel according to any one of (1) to (6) above, and a sensor panel that detects fluorescence emitted from the radiation image conversion panel, the tip of each columnar crystal The radiographic image detection apparatus by which the said radiographic image conversion panel and the said sensor panel are bonded together by making the surface of the said fluorescent substance which corresponds to the said sensor panel oppose.
(8) The radiological image detection apparatus according to (7), wherein an adhesive layer is interposed between the surface of the phosphor corresponding to the tip side of each columnar crystal and the sensor panel, A radiological image detection apparatus to which the sensor panel is bonded.
(9) The radiographic image detection apparatus according to (7) or (8), wherein the radiographic image detection apparatus has a radiation incident surface on the sensor panel side.
(10) The radiological image detection apparatus according to (7) or (8), wherein the radiological image detection apparatus has a radiation incident surface on the radiological image conversion panel side.

DESCRIPTION OF SYMBOLS 1 Radiation image detection apparatus 2 Radiation image conversion panel 3 Sensor panel 11 Support body 16 TFT substrate 18 Scintillator 19 Protective film 20 Photoconductive layer 22 Electrode 23 Planarization layer 24 Electrode 25 Adhesive layer 26 Photoelectric conversion element 28 Switch element 30 Gate line 32 Signal line 34 Column 35 35 Column 35A Tip 36 Non-column 38 Connection terminal 40 Reflective film

Claims (10)

A radiation image conversion panel comprising a phosphor containing a fluorescent substance that emits fluorescence when exposed to radiation,
The phosphor includes a group of columnar crystals formed by growing crystals of the phosphor material in a columnar shape,
Each columnar crystal is a radiation image conversion panel in which at least a tip portion is formed in a taper shape, and at least a side surface of the tip portion of the columnar crystal is covered with a reflective film. The radiation image conversion panel according to claim 1,
Further comprising a protective film covering the phosphor,
The protective film is a radiation image conversion panel which is inserted between the tip portions of the group of columnar crystals. The radiation image conversion panel according to claim 2,
The radiation image conversion panel, wherein the reflective film extends to the proximal end side of the columnar crystals rather than the protective film that enters between the distal end portions of the group of columnar crystals. The radiation image conversion panel according to any one of claims 1 to 3,
A radiation image conversion panel, wherein the reflective film is a metal reflective film. The radiation image conversion panel according to claim 4,
The metal reflective film is a radiation image conversion panel which is a film of aluminum or an aluminum alloy. The radiation image conversion panel according to any one of claims 1 to 5,
A radiation image conversion panel in which an angle of a tip of each columnar crystal is less than 90 degrees. The radiation image conversion panel according to any one of claims 1 to 6,
A sensor panel for detecting fluorescence emitted from the radiation image conversion panel;
With
A radiological image detection apparatus in which the radiographic image conversion panel and the sensor panel are bonded together with the surface of the phosphor corresponding to the tip side of each columnar crystal facing the sensor panel. The radiological image detection apparatus according to claim 7,
A radiological image detection apparatus in which the radiological image conversion panel and the sensor panel are bonded together with an adhesive layer interposed between the surface of the phosphor corresponding to the tip side of each columnar crystal and the sensor panel. The radiological image detection apparatus according to claim 7 or 8,
A radiological image detection apparatus having a radiation incident surface on the sensor panel side. The radiological image detection apparatus according to claim 7 or 8,
A radiation image detection apparatus having a radiation incident surface on the radiation image conversion panel side.