| 摘要 |
PROBLEM TO BE SOLVED: To provide the descrambler of a line rotation system possible for partial descrambling processing. SOLUTION: A read/write operation of line memories 27, 28 is alternately switched for one horizontal synchronizing period by a control means 31. On the other hand, a scramble video signal received by an input changeover means SWW is written in the line memory 27 based on a sequential counter output x2 being an output of a sequential counter 23, and read out of the line memory 28 based on a rotation counter output y2 being the output of a rotation counter 24, fed to an output changeover means SWR and a video signal subjected to partial descramble processing is outputted from an output terminal 33. Then the signal is written in the line memory 28 and read out of the line memory 27 for a succeeding horizontal synchronizing period and them the read/write operation is repeated for each one horizontal synchronizing period. |
