| 摘要 |
PURPOSE:To code efficiently the signal containing synchronizing signals and video signals of different levels like TV signals, by using such pattern that could not exist in the video signal. CONSTITUTION:The TV signal applied to an input terminal 1 is converted into the prescribed code by a coder 3 and applied to a switch circuit 4. On the other hand, the synchronizing signal is separated through a synchronizing separating circuit 5 and the switch 4 is switched with the separated synchronizing signal. Then the synchronizing code which is obtained from a synchronizing code generator 6 is selected for a synchronizing period of the TV signal. Thus the output code given from the switch 4 is applied to an input terminal 7 of a decoder through the processes such as the transmission, recording, etc. The received signal is decoded by a decoder 8 in a decording device and applied to a switch 9. In this case, the area of the synchronizing signal is coded with a level that could not exist actually. Therefore the level of a correct synchronizing signal is not decoded. As a result, the synchronizing code is detected out of the received input signal by a synchronizing code detector 10. |
