| 摘要 |
<p>The present invention is intended to an image transmission apparatus to be used for TV conference system and TV telephone system and it is an object of the present invention to provide an image transmission apparatus which realizes self-diagnosis automatically or remote operation and also attains automatic system recovery. The reference video signal generated by a pattern generator (25) is supplied to each return loop (101, 102, 103, 104, 105). The return data and original reference video signal (107) are compared with each other in a pattern diagnostic circuit (26). Result of diagnosis is displayed on a diagnosis result display panel (27). Moreover, the self-diagnosis start instruction is given from an external circuit and diagnosis result is transmitted over the line. The change-over means (50) switches the working (A1; B1) and backup circuit systems (A2; B2) of the sending and receiving sides, responsive to the diagnosis result (110). <IMAGE></p> |
