| 摘要 |
PURPOSE:To correct automatically the relative time difference among plural information signals which are transmitted through the same system at the same time by inserting synchronizing signals into plural information signals. CONSTITUTION:Synchronizing signals (marker signal) are inserted into a sound signal and a video signal previously at a transmission side, and the sound signal is transmitted while advances in phase ahead of the video signal by a specific time T. The sound signal received at a reception side is supplied to a terminal 1 and its marker signal is detected by a marker detecting circuit 3. The video signal supplied to a terminal 2 is supplied to a marker detecting circuit 4 to detects its marker, and they are supplied to a time difference measuring circuit 5. This time difference measuring circuit 5 measures the time difference between both marker signals and stores it in a trailing-stage measured value storage circuit 6. When the measurement is taken at least twice, the start signal from the time difference measuring circuit 5 allows a decision circuit to decide on whether the delay time of the sound signal to the video signal should be corrected or not on the basis of the current measured value T1 and past measured value T2 stored in the measured value storage circuits 6 and 7. |
