Electronic endoscope apparatus with signal validity monitor

An electronic endoscope apparatus comprising:

• an imaging means for outputting a plurality of systems of signals from at least one solid state imaging device said systems of signals including a first signal and a second signal;
• a plurality of signal transmitting means for transmitting said plurality of systems of signals output from said at least one solid state imaging device of said imaging means;
• a signal processing means for processing in corresponding processing modes the respective signals transmitted by said plurality of signal transmitting means, wherein said signal processing means comprises at least one pair of first and second correlated double sampling circuits corresponding to the respective first and second signals of said plurality of systems of signals;
• a signal monitoring means for judging whether the respective first and second signals transmitted by said plurality of signal transmitting means are normal or not and outputting a signal for changing the processing mode of said signal processing means on the basis of the judged result;
• wherein said signal processing means further comprises:
• a first signal selecting circuit selecting one of said plurality of systems of signals in response to the output from said signal monitoring means;
• a carrier removing circuit removing a carrier component from the output signal of said signal selecting circuit;
• a synthesizing circuit synthesizing the output signals of said plurality of correlated double sampling circuits on the basis of the output of said signal monitoring means;
• and
• a second signal selecting circuit selecting the output signal of said synthesizing circuit and the output signal of said carrier removing circuit on the basis of the output of said signal monitoring means.

An electronic endoscope apparatus comprising:

• an imaging means for outputting a plurality of systems of signals from at least one solid state imaging device, said systems of signals including a first signal and a second signal;
• a plurality of signal transmitting means for transmitting said plurality of systems of signals output from said at least one solid state imaging device of said imaging means;
• a signal processing means for processing in corresponding processing modes the respective signals transmitted by said plurality of signal transmitting means, wherein said signal processing means comprises at least one pair of first and second correlated double sampling circuits corresponding to the respective first and second signals of said plurality of systems of signals;
• a signal monitoring means for judging whether the respective first and second signals transmitted by said plurality of signal transmitting means are normal or not and outputting a signal for changing the processing mode of said signal processing means on the basis of the judged result;
• wherein said signal processing means further comprises:
• a first signal processing circuit and a second signal processing circuit, said first signal processing circuit comprising:
• said plurality of correlated double sampling circuits corresponding to the respective signals of said plurality of systems of signals;
• a signal selecting circuit selecting one of said plurality of systems of signals in response to the output from said signal monitoring means;
• a carrier extracting circuit extracting a carrier component from the output signal of said signal selecting circuit;
• a sampling clock producing circuit producing a sampling clock of said plurality of correlated double sampling circuits by the output signal of said carrier extracting circuit;
• and
• a synthesizing circuit synthesizing the output signals of said plurality of correlated double sampling circuits on the basis of the output of said signal monitoring means;
• and
• said second signal processing circuit comprising:
• a synchronizing detecting circuit synchronizing and detecting the output signal from the synthesizing circuit in said first signal processing circuit and extracting a color difference signal;
• and
• a synchronizing detecting clock producing circuit producing a synchronizing detecting clock of said synchronizing detecting circuit on the basis of the output of said signal monitoring means.

An electronic endoscope apparatus comprising:

• an imaging means for outputting a plurality of systems of signals from at least one solid state imaging device, said systems of signals including a first signal and a second signal;
• a plurality of signal transmitting means for transmitting said plurality of systems of signals output from said at least one solid state imaging device of said imaging means;
• a signal processing means for processing in corresponding processing modes the respective signals transmitted by said plurality of signal transmitting means, wherein said signal processing means comprises at least one pair of first and second correlated double sampling circuits corresponding to the respective first and second signals of said plurality of systems of signals;
• a signal monitoring means for judging whether the respective first and second signals transmitted by said plurality of signal transmitting means are normal or not and outputting a signal for changing the processing mode of said signal processing means on the basis of the judged result;
• wherein said signal processing means further comprises:
• a first signal processing circuit and a second signal processing circuit, said first signal processing circuit comprising:
• said plurality of correlated double sampling circuits corresponding to the respective signals of said plurality of systems of signals;
• a first signal selecting circuit selecting one of said plurality of systems of signals in response to the output from said signal monitoring means;
• a carrier removing circuit removing a carrier component from the output signal of said first signal selecting circuit;
• a synthesizing circuit synthesizing the output signals of said plurality of correlated double sampling circuits on the basis of the output of said signal monitoring means;
• and
• a second signal selecting circuit selecting the output signal of said synthesizing circuit and the output signal of said carrier removing circuit on the basis of the output of said signal monitoring means;
• and
• said second signal processing circuit comprising:
• a synchronizing detecting circuit synchronizing and detecting the output signal from the second signal selecting circuit in said first signal processing circuit and extracting a color difference signal;
• and
• a synchronizing detecting clock producing circuit producing a synchronizing detecting clock of said synchronizing detecting circuit on the basis of the output of said signal monitoring means.