| 摘要 |
PURPOSE:To pickup only correct data externally through ineffective data errors, by detecting the absence of a framing code at a specified period and erasing the contents of a memory. CONSTITUTION:A dropout takes place in a certain horizontal scanning period, then since a specified amount of data is not filled in a memory 5 (shift register), no framing code detection circuit 6 is operated. Thus, no FF7 is set, the Q' output goes to H level, and the output of an AND circuit 12 goes to H level when the next horizontal synchronizing signal is incoming to an input terminal 13, a reset signal is supplied to the memory 5 and the contents are all zero. Thus, even if a new data is incoming during one horizontal scanning period after occurrence of a dropout, the contents of the memory 5 at one horizontal period causing dropout are made once zero for restarting, allowing to avoid the detection of the framing code with the remaining data and the next new data and to inform only correct data externally. |
