X-ray tube control system

Claim 1

In combination: an x-ray tube including a tubular envelope having therein an electron emitting cathode disposed in spaced alignment with a portion of a rotatable anode target attached to a rotor of an induction motor; a stator of the motor disposed externally of the envelope and encircling the rotor, the stator including a plurality of interconnected coils supported on spaced pole pieces; motor control means electrically connected to the coils of the stator for sending an electrical current therethrough and producing rotational movement of the anode target; rotation sensing means coupled to the rotor for sensing rotational movement of the anode target and producing corresponding electrical output signals; tube control means electrically connectable to the cathode and the anode target of the tube for selecting parametric operating values of the tube, including X-ray tube current, X-ray tube voltage, and exposure time interval, and producing corresponding electrical output signals; and speed monitoring circuit means electrically connected to the tube control means, the rotation sensing means, and the motor control means for regulating the rotational speed of the anode target in accordance with the output signals received from the tube control means and the rotation sensing means, the speed monitoring circuit means including desired speed determining circuit means electrically connected to the tube control means for combining the electrical signals corresponding to selected values of X-ray tube current, X-ray tube voltage, and exposure time interval, and in accordance therewith producing output signals indicative of a proportionate minimum speed and a proportionate optimum speed range of rotation for the anode target.