| 摘要 |
PURPOSE:To prevent a clear noise on the screen of a monitor and the flicker on the screen from occurring by providing a detecting means and a means to input a digital signal of prescribed pattern to a digital-analog converter when detecting the fact that no normal image reproduction can be performed by the detecting means. CONSTITUTION:The detecting means 5 which detects the presence/absence of the input of an optical signal for a receiver B from a transmission line 4 and/or the fact that signal conversion processing from the optical signal to an analog image signal is performed normally, and the means 10 which inputs the digital signal of prescribed pattern to the digital-analog converter 8 when it is detected that no normal image reproduction can be performed by the detecting means 5 are provided. Therefore, the receiver B can output an image signal to the monitor 9 based on the digital signal of specific pattern even when the abnormality of a receiving state such as the interruption of a transmission signal or frame step out, etc., occurs. In such a way, it is possible to prevent the clear noise on the screen of the monitor and the flicker on the screen from occurring. |
