Radiation image converting panel

Abstract

The present invention relates a radiation image converting panel with a structure capable of arbitrarily controlling a change in luminance distribution of an entire panel surface after formation of a moisture-resistant protective film. The radiation image converting panel comprises a radiation converting film doped with Eu and covered with a moisture-resistant protective film. The Eu concentration in the radiation converting film is preliminarily adjusted such that the Eu concentration at a central portion or peripheral portion of the film falls within an optimal range, and the other film portion is provided with a positive or negative concentration gradient such that the Eu concentration thereof gradually become higher or lower than the optimal range. The luminance distribution of the entire panel in which the moisture-resistant protective film has been formed can be controlled by providing the Eu concentration to be added with a concentration gradient.

1 . A radiation image converting panel comprising:
 a support body having a first main surface and a second main surface opposing said first main surface;   a radiation converting film doped with Eu and provided on a film forming region which exists within said first main surface of said support body and includes at least a gravity center position of said first main surface, said radiation converting film being comprised of columnar crystals which are coincident or tilted at a predetermined angle with respect to a normal direction of said first main surface; and   a moisture-resistant protective film covering an exposed surface of said radiation converting film, excluding a surface of said radiation converting film that is covered by said first main surface of said support body,   wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.5 wt % or less, over said entire radiation converting film, and   wherein, in said film forming region of said first main surface, the Eu concentration of said radiation converting film, which locates on a central area around the gravity center position whose radius equals 5% or less of a minimum distance from the gravity center position to an edge of said film forming region, is set so as to fall within an optimal range of 0.01 wt % or more but 0.07 wt % or less, and the Eu concentration of said radiation converting film, which locates on a peripheral area sandwiched by the edge of the film forming region and a circumference of a reference circle centering the gravity center position whose radius equals 40% or more but 80% or less of the minimum distance from the gravity center position to the edge of the film forming region, is set so as to become lower than the Eu concentration of said radiation converting film which locates on said central area.   
   
   
       2 . A radiation image converting panel according to  claim 1 , wherein the Eu concentration of said radiation converting film locating on said peripheral area is 0.3 times or more but 0.8 times or less of the Eu concentration of said radiation converting film locating on said central area. 
   
   
       3 . A radiation image converting panel according to  claim 1 , wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.3 wt % or less, over said entire radiation converting film. 
   
   
       4 . A radiation image converting panel according to  claim 1 , wherein, in said film forming region of said first main surface, the Eu concentration distribution, which locates on a middle area sandwiched by said central area and said peripheral area, monotonically decreases along a direction directing from the gravity center position to the edge of said film forming region. 
   
   
       5 . A radiation image converting panel comprising:
 a support body having a first main surface and a second main surface opposing said first main surface;   a radiation converting film doped with Eu and provided on a film forming region which exists within said first main surface of said support body and includes at least a gravity center position of said first main surface, said radiation converting film being comprised of columnar crystals which are coincident or tilted at a predetermined angle with respect to a normal direction of said first main surface; and   a moisture-resistant protective film covering an exposed surface of said radiation converting film, excluding a surface of said radiation converting film that is covered by said first main surface of said support body,   wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.5 wt % or less, over said entire radiation converting film, and   wherein, in said film forming region of said first main surface, the Eu concentration of said radiation converting film, which locates on a central area around the gravity center position whose radius equals 5% or less of a minimum distance from the gravity center position to an edge of said film forming region, is set so as to fall within an optimal range of 0.01 wt % or more but 0.07 wt % or less, and the Eu concentration of said radiation converting film, which locates on a peripheral area sandwiched by the edge of the film forming region and a circumference of a reference circle centering the gravity center position whose radius equals 40% or more but 80% or less of the minimum distance from the gravity center position to the edge of the film forming region, is set so as to become higher than the Eu concentration of said radiation converting film which locates on said central area.   
   
   
       6 . A radiation image converting panel according to  claim 5 , wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.3 wt % or less, over said entire radiation converting film. 
   
   
       7 . A radiation image converting panel according to  claim 5 , wherein, in said film forming region of said first main surface, the Eu concentration distribution, which locates on a middle area sandwiched by said central area and said peripheral area, monotonically increases along a direction directing from the gravity center position to the edge of said film forming region. 
   
   
       8 . A radiation image converting panel comprising:
 a support body having a first main surface and a second main surface opposing said first main surface;   a radiation converting film doped with Eu and provided on a film forming region which exists within said first main surface of said support body and includes at least a gravity center position of said first main surface, said radiation converting film being comprised of columnar crystals which are coincident or tilted at a predetermined angle with respect to a normal direction of said first main surface; and   a moisture-resistant protective film covering an exposed surface of said radiation converting film, excluding a surface of said radiation converting film that is covered by said first main surface of said support body,   wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.5 wt % or less, over said entire radiation converting film, and   wherein, in said film forming region of said first main surface, the Eu concentration of said radiation converting film, which locates on a peripheral area sandwiched by an edge of the film forming region and a circumference of a reference circle centering the gravity center position whose radius equals 40% or more but 80% or less of the minimum distance from the gravity center position to the edge of said film forming region, is set so as to fall within an optimal range of 0.01 wt % or more but 0.07 wt % or less, and the Eu concentration of said radiation converting film, which locates on a central area around the gravity center position whose radius equals 5% or less of a minimum distance from the gravity center position to the edge of said film forming region, is set so as to become lower than the Eu concentration of said radiation converting film which locates on said peripheral area.   
   
   
       9 . A radiation image converting panel according to  claim 8 , wherein the Eu concentration of said radiation converting film, which locating on said peripheral area is 0.3 times or more but 0.8 times or less of the Eu concentration of said radiation converting film locating on said central area. 
   
   
       10 . A radiation image converting panel according to  claim 8 , wherein the Eu falls within the range of 0.01 wt % or more but 0.3 wt % or less, over said entire radiation converting film. 
   
   
       11 . A radiation image converting panel according to  claim 8 , wherein, in said film forming region of said first main surface, the Eu concentration distribution, which locates on a middle area sandwiched by said central area and said peripheral area, monotonically decreases along a direction directing from the gravity center position to the edge of said film forming region. 
   
   
       12 . A radiation image converting panel comprising:
 a support body having a first main surface and a second main surface opposing said first main surface;   a radiation converting film doped with Eu and provided on a film forming region which exists within said first main surface of said support body and includes at least a gravity center position of said first main surface, said radiation converting film being comprised of columnar crystals which are coincident or tilted at a predetermined angle with respect to a normal direction of said first main surface; and   a moisture-resistant protective film covering an exposed surface of said radiation converting film, excluding a surface of said radiation converting film that is covered by said first main surface of said support body,   wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.5 wt % or less, over said entire radiation converting film, and   wherein, in said film forming region of said first main surface, the Eu concentration of said radiation converting film, which locates on a peripheral area sandwiched by an edge of the film forming region and a circumference of a reference circle centering the gravity center position whose radius equals 40% or more but 80% or less of the minimum distance from the gravity center position to the edge of the film forming region, is set so as to fall within an optimal range of 0.01 wt % or more but 0.07 wt % or less, and the Eu concentration of said radiation converting film, which locates on a central area around the gravity center position whose radius equals 5% or less of a minimum distance from the gravity center position to the edge of said film forming region, is set so as to become higher than the Eu concentration of said radiation converting film which locates on said peripheral area.   
   
   
       13 . A radiation image converting panel according to  claim 12 , wherein the Eu concentration falls within the range of 0.01 wt % or more but 0.3 wt % or less, over said entire radiation converting film. 
   
   
       14 . A radiation image converting panel according to  claim 12 , wherein, in said film forming region of said first main surface, the Eu concentration distribution, which locates on a middle area sandwiched by said central area and said peripheral area, monotonically decreases along a direction directing from the gravity center position to the edge of said film forming region.