JPS6432836A - Signal processing circuit for endoscope - Google Patents

Abstract

PURPOSE:To reduce the number of parts and to reduce cost, by making the output parts of both of a character signal and a color bar signal common and outputting the same at a normal voltage level by the change-over of a change- over means. CONSTITUTION:In an electronic endoscopic apparatus 41, a signal processing circuit 42 is provided between a D/A converter 26 and a matrix circuit 31. A CPU 28 outputs a mode discriminating or mode change-over signal CB/CH from an output terminal T1 corresponding to a mode outputting a color bar or character signal and an amplifier 44 changes over the resistance of a reversal input terminal to R2 or R1/R2 corresponding to the mode change-over signal CB/CH of the CPU 28 and the voltage of the output terminal Va of the amplifier 44 is made variable. The D/A converter 26 is controlled to a state outputting no D/A converting signal by the blank signal from a control circuit 45 and the control circuit 45 outputs the blank signal when the color bar signal is outputted. By providing the signal processing circuit 42, an encoder 32 outputs the color bar signal at the time of a color bar signal mode and outputs the character signal in a state superposed on a composite signal at the time of a character signal mode.