| 摘要 |
PURPOSE:To effective suppress a defective fetch of a picture signal by controlling the storage of an input picture signal to a picture memory means according to the result of detection of a fault detection means and a synchronizing signal separated by a synchronizing separator means. CONSTITUTION:A horizontal synchronizing signal outputted from a synchronizing separator circuit 12 is fed to a control circuit 22 and a vertical synchronizing signal is fed to the control circuit 22 and a vertical synchronizing signal fault detection circuit 20. The vertical synchronizing signal fault detection circuit 20 detects a fault of the vertical synchronizing signal and gives the result of detection to the control circuit 22. The control circuit 22 controls the storage of the picture memory 16 according to the horizontal synchronizing signal from the synchronizing separator circuit 12, the vertical synchronizing signal and the fault detection result from the vertical synchronizing signal fault detection circuit 20. Thus, even when a fault exists in the vertical synchronizing signal, proper picture fetch is attained. |
