Patent ID: 8374315

Claim:
An x-ray tube comprising: an anode; a flat thermionic emitter comprising a plurality of emitter regions in a plane of said flat thermionic emitter that are respectively spaced from each other in said plane, said emitter generating an electron beam between said emitter and said anode comprised of a plurality of partial beams respectively generated by said emitter regions; at least one control electrode arrangement located between said emitter and said anode that generates a variable electrical field and that comprises a plurality of passages therein respectively associated with the respective partial beams, each of said passages controlling the respective partial beam passing therethrough; said control electrode arrangement comprising a plurality of control electrode layers located in succession between said emitter and said anode, and each of said control electrode layers exhibiting a different voltage and one of said control electrode layers being located in said plane; and said emitter regions and said control electrode arrangement being configured and controlled relative to each other to cause substantially an entirety of each of said partial beams to pass through the passage associated therewith in said control electrode arrangement.