| 摘要 |
PURPOSE:To prevent a virtual drop of the appearance of S/N ratio of a reproducing picture in case when the intensity of illumination is low, by amplifying a luminance signal when the intensity of illumination of an object to be photographed is low, and also setting a color signal below a reference level. CONSTITUTION:In case when the intensity of illumination is low, a switch S1 is connected to a contact (c), an amplifier 3 becomes high gain, and even when a level of a signal Sn has dropped, it is compensated to a reference level. A chrominance signal Sc and an index signal Si contained in the signal Sa from the amplifier 3 are bypassed through a capacitor C1 and an FETQ3, are attenuated, and the signal Sa becomes a composite signal consisting of a luminance signal Sy of a reference level, the chrominance signal Sc of a level which has been attenuated from the reference level, and the index signal Si. |
