Patent ID: 7734015

Claim:
An X-ray tube comprising: an anode housing unit having an X-ray emission window for taking out X-rays generated therein an internal portion; an anode, disposed inside said anode housing unit, having an X-ray target; an electron gun for emitting electrons toward said X-ray target to generate X-rays in a direction from said X-ray target toward said X-ray emission window; an electron gun housing unit in which said electron gun is housed; and a metal cylindrical member housing a part of said anode in which said X-ray target is included, wherein said anode has a main body having a shape extending along a predetermined axis orthogonal to an electron incidence direction from said electron gun, and a protruding portion extending in the axis line direction of said main body from a tip of said main body, wherein said protruding portion has an inclined surface that intersects the axis line at a predetermined angle and matches an electron incidence surface of said X-ray target, a pair of side surfaces that extend in the same direction as the axis line and are disposed in parallel while sandwiching said inclined surface, and a rear surface that is sandwiched by said pair of side surfaces and is positioned at an opposite side of said electron gun housing unit with respect to said inclined surface, wherein a distance between said pair of side surfaces of said protruding portion is shorter than a width of said main body in the same direction as the distance, wherein said metal cylindrical member has a through hole for installation of said electron gun housing unit and is arranged so as for an inner surface thereof to surround a stepped portion constituted by said tip of said main body and at least said pair of side surfaces of said protruding portion, and wherein said rear surface of said protruding portion and an outer surface of said main body constitute a consecutive curved surface with no stepped portion.