Patent ID: 7248281

Claim:
An electronic endoscope apparatus comprising: an electronic endoscope equipped with an image pickup device; a main unit which is connected with the electronic endoscope and includes a processor unit; a sample/hold circuit which samples and holds a video signal obtained by the image pickup device; a common power/signal line which connects the electronic endoscope with the main unit; a power supply circuit which is installed in the main unit and supplies power to the electronic endoscope via the common power/signal line; a scope-side waveform superimposing circuit which superimposes a video signal obtained by the image pickup device on the power transmitted through the common power/signal line and superimposes scope-side reference pulses on a plurality of horizontal scanning blanking periods in a field or frame of the video signal; a processor-side waveform superimposing circuit which superimposes processor-side reference pulses on a plurality of horizontal scanning blanking periods that exist in a field or frame of the video signal supplied via the common power/signal line and that are not superimposed with the scope-side reference pulses; a processor-side separating circuit which separates the video signal and scope-side reference pulses superimposed on the common power/signal line; a processor-side synchronizing signal generator which forms a signal synchronized with the scope-side reference pulses outputted from the processor-side separating circuit; a scope-side separating circuit which separates the processor-side reference pulses superimposed on the common power/signal line; and a scope-side timing generator which forms a signal synchronized with the processor-side reference pulses outputted from the scope-side separating circuit.