X-ray system with aligned source and slits

Claim 1

In a cassette for a radiographic system or the like, the combination of: a pair of electrodes comprising an anode and a cathode, at least one of said electrodes being cylindrical; means for mounting said electrodes in spaced relation with a gap therebetween to form a unit having an axis of rotation; a dielectric sheet carried in said gap on said one electrode; means for maintaining a gas in said gap; means for connecting a high voltage electric power supply across said electrodes for attracting charged particles towards said one electrode for deposit on said sheet to form a latent electrostatic image; means for moving said unit along a path during an exposure; means for rotating said sheet and one electrode about said axis as said unit is moved; an X-ray source; first means defining a first slit; second means defining a second slit; and means for mounting said source and first slit on one side of a zone for an object to be X-rayed and for mounting said second slit and unit on the other side of the zone, with said source, slits and unit aligned defining an X-ray path from the source through the slits to the unit, the gas in the gap absorbing X-ray photons and emitting charged particles; with said means for moving said unit including means for scanning said source across the zone in synchronism with unit movement maintaining said source and slits in alignment.