SIGNAL PROCESSING CIRCUIT OF ELECTRONIC ENDOSCOPE

摘要

PROBLEM TO BE SOLVED: To compensate the shortage of quantity of light due to the response delay of a light shielding mechanism in an electronic endoscope which provides still pictures of high quality and moving pictures that faithfully reproduce movement. SOLUTION: For moving pictures, pixel-mixture signals are output from a CCD 12 in order to faithfully reproduce movement. For still pictures, signals of all pixels obtained with the CCD 12 through one exposure are read as a light-shielding period set by a light shielding plate 36 is utilized. These outputs of the CCD 12 are amplified by an amplifier 21 at a gain which is (1+α) times that for the moving pictures, whereby the shortage of quantity of light due to the response delay of the light shielding plate 36 is compensated. This amplification signal is output via memories 23-25 to a mixing circuit 26, where the pixel-mixture signals are formed. Hence high-quality still pictures of optimum brightness are obtainable.