| 摘要 |
PURPOSE:To prevent troubles of the direct current operation from occurring by stopping generation of clamp pulses during the horizontal period during which defects are generated in the black reference signal generating pixels and effecting direct current reproduction of the line using black reference signals for one preceding horizontal line. CONSTITUTION:In the image pickup signal outputted from an image pickup element 31, when the defect signal is produced based on the image defect in the black reference signal in the second line, the detection signal of the '0' level is outputted from an address comparator 37 as the horizontal scanning for the second line is started. During the black reference signal period for the horizontal period, a clamp pulse of '1' is outputted synchronizingly with the black reference signal from a synchronism signal generator 32, since the detec tion signal of the '0' level is outputted fro the comparator 37, an AND circuit 38 stops the outputting of this pulse. When the time constant of the charging and discharging of a capacitor 41 is set to be longer than the horizontal scan ning period for two lines, direct current restoration is performed on the basis of the black reference level one horizontal line before when the pixel defect has not occurred. |
