| 摘要 |
PURPOSE:To attain selective service to a specific subscriber by applying a mask processing to the content of a part corresponding to screen information, broadcasting it and giving a ''key'' decoding the mask processing to the specific subscriber at the receiving side. CONSTITUTION:In transmitting the video signal of a mask form, the signal of an original signal source 1 is transmitted from a transmission section 3 via an operating section setting circuit 4 and an operating circuit 5. The circuit 4 extracts a real video signal section from the original signal and the circuit 5 applies an operating processing to this signal. On the other hand, after a signal received by a receiving section 6 is restored to an inverse operating section setting circuit 8 via an inverse operating circuit 9, the signal is transmitted to a display section 10. The circuit 8 discriminates a section performing operating processing based on horizontal and vertical synchronizing signal in the received signal and the circuit 9 processes inverting operation for the signal of the section. |
