Patent ID: 6088425
Filing Date: 2000-07-11
Classification: H05G

Abstract:
An X-ray apparatus comprising:a rotary anode type X-ray tube including a rotary anode having an X-ray emission target section, a cathode for emitting an electron beam to the target section of said rotary anode, a rotary structure to which said rotary anode is fixed, a stationary structure for rotatably supporting said rotary structure, and a bearing disposed between said rotary structure and said stationary structure;a power supply device for causing the electron beam to be incident on said rotary anode of said X-ray tube to emit X-ray radiation; andan X-ray emission control device for controlling the power supply device to control the X-ray radiation, said X-ray emission control device including:first setting means for setting data information corresponding to a maximum permissible storage heat quantity (Qlm) of said rotary anode;first calculating means for calculating data information corresponding to a present anode storage heat quantity (Qt) based on the cooling characteristic (Ct) of said rotary anode;second calculating means for calculating data information corresponding to a next predicted anode input total heat quantity (Qsn) by calculation using data information corresponding to the anode input power (P) and X-ray emission continuation time (T) from the start of the X-ray emission to the end of the X-ray emission in the next predicted X-ray emitting condition;second setting means setting data information which is at least one of data information corresponding to a correction function (K(p)) determined depending on the anode input power (P) of said X-ray tube, data information corresponding to a correction function (L(T)) determined depending on the X-ray emission continuation time (T), data information corresponding to a correction function (M(f)) determined depending on the X-ray focal point size (f), and data information corresponding to a correction function (N(r)) determined depending on the anode rotation speed;third calculating means for calculating data information corresponding to a next imaginary anode storage heat quantity (Qs) in the next X-ray emitting condition by calculation using the at least one data information set by said second setting means and data information corresponding to the next predicted anode input total heat quantity (Qsn);fourth calculating means for deriving data information indicating permission or inhibition of the X-ray emission in the next X-ray emitting condition by calculation using data information corresponding to the maximum permissible storage heat quantity (Qlm), the present anode storage heat quantity (Qt) and the next imaginary anode storage heat quantity (Qs);third setting means for changing the anode input power (P) during the X-ray emission continuation time; andfourth setting means for intermittently effecting X-ray emission.