PARABOLA WAVE GENERATING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To simulatively vary the order of a correction curve between the upper/lower parts and the central part of a screen by providing the first and second slice circuits for sampling a signal equal to or higher than some level, the first and second gain control circuits, e.g. for controlling the amplitude of sliced output. SOLUTION: A sawtooth wave generating means 1 generates the monotonously increasing sawtooth wave of vertical synchronization based on an inputted vertical synchronizing signal. An absolute value pulse generating circuit 2 slices the output of the means 1 at some level. The first slice circuit 3 slices a part on an upper side than some level at a part folded back linearly symmetrically. The first gain control circuit 4 adjusts the output amplitude of the circuit 3. The second slice circuit 5 slices a part on an upper side than some level at a part which is not folded back linearly symmetrically. The second gain control circuit 6 adjusts the output amplitude of the circuit 5.