| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic endoscopic device capable of making the level difference in terms of DC caused by reducing the power consumption so small that a dynamic range need not be extended even when the power consumption is reduced. SOLUTION: An output signal from the CCD 10 of an electronic endoscope 2 is transmitted through a coaxial cable 18, passes through a changeover switch 52 from the trailing end of the cable 18 and is inputted in a preamplifier 20. At the trailing end, the level difference in terms of DC is made when a switch S connected to a resistance R1 in series is turned on in a signal readout period and turned off in a signal non-readout period according to a control signal from a control circuit 21 so as to restrain the power consumption, but the level difference is made small so that the dynamic range of the preamplifier 20 need not be extended by inputting a value obtained by sample-holding the level of an OB(optical black) part at the trailing end side in the signal readout period by a sample-hold circuit 51 in the preamplifier 20 through the contact (b) of the switch 52 in the signal non-readout period.
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