PROBLEM TO BE SOLVED: To suppress deflection of a top plate while avoiding deterioration of image quality and restriction of a tilt angle.SOLUTION: An X-ray computer tomographic apparatus includes a top plate, an X-ray source, an X-ray detector, a reinforcement plate, a support mechanism, and a driving control unit. A subject is placed on the top plate. The X-ray source generates an X-ray. The X-ray detector detects an X-ray generated from the X-ray source and transmitting the subject. The reinforcement plate is provided inside the top plate, and reduces deflection of the top plate. The support mechanism supports the top plate and the reinforcement plate so that they can move with respect to a longitudinal direction of the top plate. The driving control unit drives the support mechanism to move the top plate and the reinforcement plate with respect to the longitudinal direction, and restricts movement with respect to the longitudinal direction of the reinforcement plate according to an irradiation range of the X-ray from an X-ray tube.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2019,JPO&INPIT【課題】画質の劣化やチルト角の制限を回避しつつ、天板の撓みを抑制すること。【解決手段】実施形態に係るＸ線コンピュータ断層撮影装置は、天板、Ｘ線源、Ｘ線検出器、補強板、支持機構及び駆動制御部を有する。天板には被検体が載置される。Ｘ線源は、Ｘ線を発生する。Ｘ線検出器は、Ｘ線源から発生され被検体を透過したＸ線を検出する。補強板は、天板の内部に設けられ、天板の撓みを低減する。支持機構は、天板と補強板とを天板の長軸方向に関して移動可能に支持する。駆動制御部は、天板と補強板とを長軸方向に関して移動させるために支持機構を駆動し、Ｘ線管からのＸ線の照射範囲に応じて補強板の長軸方向に関する移動を制限する。【選択図】 図１
