Patent ID: 7831020

Claim:
An X-ray tube for generating X-rays at an X-ray target, by making electrons emitted from an electron gun incident on said X-ray target, said X-ray tube comprising: a target housing unit including: a side wall portion being a hollow member having a tube axis extending along a predetermined direction and housing said X-ray target therein, said side wall portion being disposed so as to surround the tube axis; and an X-ray emission window, positioned at an end side of said side wall portion and disposed on a surface intersecting the tube axis, for taking out the X-rays generated at said X-ray target to an exterior; and an electron gun housing unit being a hollow member having one end mounted onto said side wall portion of said target housing unit so that a tube axis thereof intersects the tube axis of said target housing unit, said electron gun housing unit housing at least a part of said electron gun while an electron emission exit of said electron gun is directed toward said X-ray target, wherein said electron emission exit of said electron gun is arranged such that a center of said electron emission exit is positioned on a center axis of said electron gun, and wherein said electron gun is held by said electron gun housing unit while the center of said electron emission exit of said electron gun is shifted more toward said X-ray emission window side than the tube axis of said electron gun housing unit.