| 摘要 |
PURPOSE:To facilitate the change and the selection of the type of a memory by constituting the picture memory by the plural memories equal in the number of secondary screens and adding a secondary screen selecting signal to a writing address signal and a reading address signal. CONSTITUTION:A signal for a main screen obtained from a changeover circuit 5 is applied to a Y/C processing and synchronization processing circuit 6 and the signal for the secondary screen is applied to a Y/C processing and synchronization processing circuit 7. The secondary screen signal obtained from the circuit 7 synchronizes with a synchronizing signal of the secondary screen signal, written in the memory 10 and the secondary screen signal is read synchronously with the synchronizing signal of the main screen signal from the memory 10. The memory 10 is constituted of for instance, four memories 10B-10E which are equal in the number of the secondary screens, and to the memories 10B-10E, common horizontal addresses 0-31, and vertical addresses 0-63 are applied. Screen selecting switches 21A-21E are provided, in accordance with a selecting operation, the screen selecting signal is applied to a control circuit 19 and a memory control circuit 13 from a screen selecting circuit 22. Thereby the screen can easily be selected.
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