in an x - ray imaging apparatus , unwanted electron charges caused by pulsatory x - ray trailing edges are eliminated from an x - ray image signal of a biological body under medical examination . the x - ray imaging apparatus comprises : an x - ray generator for generating a plurality of pulsatory x - ray beams ; an x - ray controlling unit for supplying an x - ray projection controlling signal to the x - ray generator in order to project an x - ray pulse beam having a predetermined pulse width to a biological body under medical examination from the x - ray generator , thereby producing an x - ray image of the biological body under medical examination ; an optical converter for converting the x - ray image into a corresponding optical x - ray image signal of the biological body under medical examination ; an imaging unit for imaging the optical x - ray image signal derived from the optical converter to store the imaged optical x - ray image signal as electron charges therein ; a driving unit for driving the imaging unit in such a manner that only electron charges produced while projecting the x - ray pulse having the predetermined pulse width to the biological body in response to the x - ray projection controlling signal , are read out as an effective x - ray image signal of the biological body under medical examination ; and , a display unit for displaying thereon an effective x - ray image of the biological body under medical examination in response to the effective x - ray image signal .