| 摘要 |
PURPOSE:To obtain a chroma signal which is invariable in the optimum phase, and to deal with even a decrease in line density, etc., and thus prevent deterioration in picture quality, by switching a switch according to the output of a phase comparator. CONSTITUTION:With regard to vertical and horizontal synchronism relation, when a main memory 10 is read out by a control circuit 30 according to a clock signal from a readout clock generating circuit 32, an output with normal synchronism relation is obtained. With regard to the phase of a color subcarrier, phase reference data from the circuit 32 is compared with phase discrimination data from a latch circuit 17 by a phase comparing circuit 9, and a change-over switch 28 is placed on the side of a terminal (a) when they are in phase with each other, or on the side of a terminal (b) when out of phase to invert a chroma signal, thereby sending a chroma signal in the same color subcarrier phase with the phase reference data to an adder 29. Thus, a chroma signal invariably in correct phase is obtained. |
