| 摘要 |
PURPOSE:To improve deterioration of a subordinate screen image, by stopping corrections of interlacing when write operation of a one-field memory is stopped. CONSTITUTION:When the voltage of electric power source 21 is supplied to readout address generating circuit 16 and interlacing correcting circuit 17 with the subordinate screen still switch closed, readout address generating circuit 16 stops the supply of an address for data transfer from the line memory to the field memory and interlacing correcting circuit 17 controls readout address generating circuit 16 to stop interlacing corrections. Therefore, closing subordinate screen still switch 20 stops the write operation of the field memory and also stops interlacing corrections. Consequently, even if the phase difference of a master screen video signal changes, an interlacing correction position moves vertically on a still picture on the subordinate screen, so that the subordinate screen picture will not deteriorate. |
