Centering circuit arrangement for the automatic correction of faulty centering formations of the component colour images of a more bending color television camera

摘要

An automatic centering system is provided for multiple tube color cameras utilizing a plurality of channels of electronics, wherein at least one channel generates a signal which is the first derivative of either the red, green or blue color video signal introduced into the channels from a video color camera. In one embodiment of the centering circuit, the red and blue color signals are introduced to respective channels of the system, and each are multiplied by the first derivative of the green color signal. The resulting pair of centering signals are integrated to provide error signals which represent the amount and direction of any mis-centering between the green component image and the red and/or blue component images respectively. In another embodiment of the centering circuits, the first derivatives of the red and blue signals are each multiplied by the green color signal. The resulting pair of centering signals are integrated to provide error signals which represent the amount and direction of any mis-centering between the green and red and/or blue component images. Either of the embodiments may be used to correct vertical and/or horizontal mis-centering. In either embodiment, any mis-centering in either the vertical or horizontal direction is used to control up/down counter means, whereby a corresponding analog correction signal is supplied, via digital-to-analog means, to the scanning apparatus of the respective camera tubes.