Patent ID: 7675039

Claim:
A radiation detector, comprising: a phosphor sheet configured to convert radiation rays transmitted through a specimen into light, wherein the phosphor sheet comprises: a support having a sheet shape, and a phosphor layer including a layer coated on said support with powder of a rare earth oxysulfide phosphor activated by europium of concentration in a range of 0.01 mol % to 3.5 mol %, wherein the rare earth oxysulfide phosphor powder has an average particle size in a range of 2 μm to 15 μm, wherein a filling factor of the phosphor powder in the phosphor layer is in a range of 60% to 80%, and the phosphor layer has a thickness in a range of 80 to 300 μm, and the rare earth oxysulfide phosphor has a composition expressed by: general formula: (R 1-a Eu a ) 2 O 2 S, wherein, in the general formula, R is at least one kind of element selected from Gd, Lu, Y and La, and a is a number which satisfies 1×10 −4 ≦a≦3.5×10 −2 ); a photoelectric conversion film on which the phosphor layer of said phosphor sheet is integrally layered and bonded, and which converts the light from said phosphor sheet into electric charges, wherein the photoelectric conversion film comprises an amorphous silicon film or a single crystal silicon film; and a charge information reading section having a plurality of pixels arranged in an array form in contact with said photoelectric conversion film and reading out the electric charges generated on said photoelectric conversion film for each of the plurality of pixels as image signals of the radiation rays, wherein said phosphor layer has a surface bonded onto the photoelectric conversion film by an adhesive that transmits light, wherein the surface has a surface roughness of 0.5 μm or less in average roughness Ra, wherein the surface has been smoothed by a treatment using a metal roll or a metal plate.