Abstract: The invention provides a coil device having horizontal and vertical deflection coils around an outer surface of an image pickup tube to generate magnetic fields for deflecting electron beams in the horizontal and vertical directions, respectively. A correction coil is disposed between the outer surface of the image pickup tube and the horizontal deflection coil so as to correspond to the position of the vertical deflection coil. The number of turns of the correction coil is smaller than that of the vertical deflection coil. A signal for correcting scanning distortion of the electron beam caused by the deflection magnetic fields is supplied to the correction coil. The time constant of the correction coil is smaller than the period of the horizontal deflection signal. The correction coil is made of a printed circuit wiring.

Abstract: A color television camera apparatus having pick-up tubes provided for three primary color components, process amplifiers and an adjustment control circuit for supplying an amount of the adjustment to compensating circuits in the process amplifiers in response to output signals from the process amplifiers. The process amplifiers contain A/D converters connected to the inputs of the amplifiers, respectively. The process amplifiers and the adjustment control circuit digitally process the signals.

Abstract: A focusing current or voltage applied to a focusing coil or focusing electrode to focus an electron beam on a target of a camera tube is modulated by a modulation signal so that the focusing current or voltage varies between a maximum value and a minimum value with its average value as the center. The focusing states of the electron beam at the maximum and minimum values of the modulated focusing current or voltage are detected by a video signal from the pickup tube. Based on this detection of focusing states of the electron beam, the average value of the modulated focusing current or voltage is corrected in such a way that the focusing states of the electron beam become equal to each other which correspond to the maximum and minimum values of the modulated focusing current or voltage.

Abstract: A scanning-area rotation device for an image pickup tube has a coil (10) for rotating a scanning-area by an electron beam on the target surface of an image pickup tube (14), a shield ring (46) for electrostatically shielding the coil (10) from the target of the image pickup tube (14), and a shield cover (44) for magnetically shielding the coil (10). The shield ring (46) electrostatically shields the target and signal circuit connecting to the target from the coil (10), but does not shield a magnetic flux from the coil (10) to the target. The shield cover (44) shields a magnetic flux developed by the coil (10) and extending to the exterior of the cover (44).