CIRCUIT DIAGNOSTIC SYSTEM OF VIDEO SIGNAL PROCESSING CIRCUIT SYSTEM

摘要

PURPOSE:To detect earlier where a failure occurs or not in a circuit system processing a video signal by providing a video signal detecting means to the said circuit system and diagnosing the said circuit system in response to the output signal. CONSTITUTION:A data transferred to a serial parallel converting section 4 is converted at the section 4 via a buffer 3 through DMA transfer from a memory 1 and converted into a video signal. This video signal is applied to a print mechanism 6 via a driver 5 and a video signal detecting circuit 10. The circuit 10 sets a flip-flop 11 in response to the video signal 16 and a clock signal 15. Similarly, a flip-flop 12 is set. The output signal of the flip-flops 11, 12 is led to an exclusive OR circuit 13 and the video signal is obtained by its output and the clock signal 15 or the like.