| 摘要 |
PURPOSE:To reduce the capacity of a picture memory and to enhance secrecy by changing the transmission sequence of the picture of a horizontal scanning line constituting one screen at random, dividing and superimposing the picture of one horizontal scanning line to more than two horizontal scanning lines, the transmitting/receiving them. CONSTITUTION:The position of transmitting sequence data is decided in a transmission sequence memory 7 by four bits and the data is sequentially inputted thereafter. A writing address is decided according to the contents of the transmission sequence memory 7 and the output of the horizontal scanning line counter of a line counter 4. A horizontal division is executed by the output of a multiplier circuit 6. The writing and the reading of memories 12, 13 are controlled in a control circuit 9. 21H-28H writes in the memory and 29H-36H write to the memory 13. In the 29H-36H, the contents are sequentially read from the memory 12. |
