| 摘要 |
PURPOSE:To obtain a stable NTSC color television signal, by forecasting the picture phase of the next field, and latching a write line address signal of the memory by means of this forecasting signal. CONSTITUTION:An output of the variable delay circuit 60 forecasts the beginning of the next picture, and the latch circuits 64, 65 are latched at the same time by this output. The address which has been latched by the latch circuit 64 is transferred to the line address counter 66, and immediately after a forecasting signal has been generated, the read side address is made to conform with the write side address. A signal which is varied depending on an even or odd number of the field of the write side is input to an output of the latch circuit 65, and it is latched by the latch circuit 79. The outputs of the latch circuits 79 and 80 indicate even or odd numbers of the fields of the write side and the read side, and a signal, which discriminates in accordance with the said result whether even or odd numbers of the fields of the write side and the read side are comforming or not, can be obtained. |
