PERIPHERAL REGISTRATION CORRECTION SYSTEM

PURPOSE:To correct the gradient of scanning lines partially at a screen peripheral part by extracting nearly maximum and minimum values of a saw-tooth wave voltage which synchronize with horizontal and vertical deflecting operations, and then superposing them on a vertical and a horizontal centering current respectively as correction signals. CONSTITUTION:Saw-tooth wave voltage generating circuits 12 and 15 generates the 1st and 2nd saw-tooth wave voltages which synchronize with horizontal and vertical deflecting operations. Then, clipping circuits 11 and 15 extract parts of the 1st and 2nd saw-tooth wave voltages from maximum values within prescribed voltage ranges, and parts from minimum values within prescribed voltage ranges, thereby extracting the 1st and 2nd correction voltages. Further, those correction voltages are level-adjusted by level adjusting circuits 8A and 8B over a positive and a negative amplitude range to generate the 1st and 2nd correction signals. The 1st correction signal is superposed upon a vertical centering current and the 2nd correction signal is superposed upon a horizontal centering current.