Abstract: An X-ray image pickup tube converts a transmitted X-ray image into electric signals. The pickup tube includes a target structure having a fluorescent element, and a translucent conductive film for receiving a high voltage, with a photoconductive film laminated thereupon. The fluorescent element receives transmitted X rays in a two-dimensional distribution, and converts them into visible rays in a two-dimensional distribution. The translucnet conductive film is optically coupled to a surface of the fluorescent element opposite from an X-ray incident surface thereof. The photoconductive film includes an amorphors semiconductor layer which converts the visible rays transmitted in a two-dimensional distribution through the translucent conductive film, into electric charges in a two-dimensional distribution, and which multiplies the electric charges in the two-dimensional distribution based on electric fields formed by the high voltage applied to the translucent conductive film.

Abstract: A two-dimensional radiation detector for obtaining a radiographic image as converted into electric signals. The detector has a multi-layer structure including a scintilator, a translucent electrode film, a photoconductive film and a scan switch layer. The scan switch layer includes conductors arranged in matrix form and in contact with the photoconductive film, a plurality of FETs corresponding to the conductors arranged in matrix form, and a uniformly planar conductor for successively applying a bias voltage through the FETs to the matrix conductors row by row. Each FET has a drain electrode connected to one of the matrix conductors, a source electrode connected to the uniformly planar conductor, and a gate electrode connected to the drive circuit. The translucent electrode film includes column conductors corresponding to columns of the matrix conductors, each of the column conductors being connected to a signal reading line.