| 摘要 |
PURPOSE:To correctly compensate X-ray tube current by performing compensation in connection with the compensation value in the condition which way previously compensated. CONSTITUTION:When the signals from a tube voltage setting device 1 and a tube current setting device 2 are entered into an operation circuit 3 by a specified program, the operation circuit 3 calculates the required filament current value by using the emission characteristic data which was prestored in memory 11 and sends it out to a DA converter 4. The output of the DA converter 4 is entered into a filament current control circuit 5. It applies a specified current to the filament of an X-ray tube 8 and heats it. Then the preset tube voltage from the high voltage generator circuit 8 is applied to an X-ray tube 9. Tube current is measured by a tube current measuring device 7 and is entered into the operation circuit 3 through a AD converter 6. In the operation circuit 3, compensation coefficient is calculated based on the previous tube current and the filament currnt is compensated by this compensation coefficient. |
