PURPOSE: To allow an unskilled person to determine the position of a positioning device by providing a sensor receiving the light from an electron beam linear accelerating/irradiating device, calculating the drift between the rotating centers of the electron beam linear accelerating/irradiating device and a revolving chair, and automatically controlling the sliding system of the revolving chair.
CONSTITUTION: An artificial positioning device 42 having a sensor 311 is fitted to the back rest of a revolving chair 300. The position of the laser beam radiated from an electron beam linear accelerating/irradiating device 41 coincides with the rotation center of the electron beam linear accelerating/irradiating device 41, and the sensor 311 of the artificial positioning device 42 feeds the change of the potential of the portion where the laser beam is irradiated to an image analyzing means 43 as the output signal. The image analyzing means 43 calculates the drift between the signal indicating the position of the laser beams and the signal indicating the position of the rotation center of the revolving chair 300, and a control circuit 44 controls a servo motor adjusting the sliding systems of the revolving chair 300 to match the rotation centers of the electron beam linear accelerating/irradiating device 41 and the revolving chair 300.
KANEKO ITSUO
HAYASHI MINORU
TOOYAMA YASUTSUNE
