Patent US 4,567,348

A device for automatically controlling the movement of a welding torch (10) while welding an elongated joint (18). A charge injection television camera (30) is carried on a movable support (20) and includes a matrix of individual light sensing video elements (pixels, 32) which generate voltages responsive to light reflected off of the joint (18) and surrounding areas of the workpiece (12). The voltages produced by the pixels (32) are converted to digital words which are fed to a microprocessor (54) for generating an error signal. This error signal is fed to a digital motor (26) which is used to drive a movable support (20) upon which the television camera (30) is carried.