Diagnostic X-ray apparatus

Claim 1

A diagnostic X-ray apparatus for producing visible difference images from X-ray images obtained from pulsed X-ray radiation, comprising: an X-ray generating source for emitting pulsed X-ray radiation to produce a pulsed X-ray image; television means, including a television camera having a predetermined field rate, for converting said X-ray image into a series of analog video signals; synchronizing means for generating field synchronizing signals at the field rate of said television camera; exposure control means reponsive to said field synchronizing signals for generating X-ray exposure signals to control the exposure period of the pulsed X-ray radiation emitted from said X-ray generating source, said exposure period being less than the interval of said field synchronizing signals, and said exposure control means including means for generating field blanking signal synchronously with the exposure period of said X-ray generating source; analog-to-digital converting means for converting into digital video signals said analog video signals corresponding to a complete television field image resulting from said pulsed X-ray radiation and following said field blanking signals; a digital memory system including means for storing said digital video signals in a predetermined sequence; subtracting means for producing digital difference video signals by performing a subtraction between digital video signals recently stored and digital video signals previously stored in said digital memory system; a digital-to-analog converter for converting said digital difference video signals from said subtracting means into analog difference video signals; and display means for producing visible difference images corresponding to said analog difference video signals.