Abstract: X-ray film images are projected onto the target plate of a video pickup tube such as a vidicon, in a video camera of the type used in closed video systems. The camera includes special circuits to compensate for the wide variation in intensity of light which will be projected from x-ray films these circuits including means for automatic brightness control and means for automatic target voltage control. The circuits for automatic brightness control include an amplification correction circuit which utilizes a portion of the amplified composite video signal to produce a DC correction voltage which is applied to the gain biasing circuit of one video amplifier stage to either increase or reduce the gain in response to the projected light, and a blanking correction circuit provides a DC correction voltage to be applied to the clamping circuit to correct the blanking pulse or pedestal amplitude in response to the amount of light projected.

Abstract: An x-ray generator tube which includes an electron gun for directing a focused high energy electron beam toward an anode presenting an enlarged face inclined relative to the electron beam; with the tube having deflection coils for sweeping the beam across the enlarged anode face producing a moving focal spot. The tube envelope provides a shielded point-source window oriented with respect to the anode to pass only a thin beam of the x-rays which are generated at the moving focal spot, thereby producing a sweeping beam of x-rays. The sweeping x-ray beam is directed through the subject to an x-ray sensitive video pickup tube which is similar to a TV camera pickup tube, and which includes a face plate having a mosaic of chemically treated globules sensitive to x-rays which produces an electric image corresponding to the x-ray image produced by the sweeping x-ray beam passing through the subject being x-rayed. This mosaic is scanned and the pickup tube produces a video output signal in a conventional manner.