| 摘要 |
PURPOSE:To facilitate the detection of a defective address and the writing of defective information, by picking up a white and black objective, regarding the resulting signal other the white and black objective as a detecting signal corresponding to the defective address, and controlling a defect correcting circuit. CONSTITUTION:A video signal S1 from a solid-state image pickup element is supplied to a terminal 12. At this time, a switch 13 is at a side (a) when a subject is white or at a side (b) when black. A signal S1 triggers a monostable multivibrator 14, and its trailing edge is differentiated by a differentiating circuit 15 to obtain an output S2, which is applied to an NOR gate 16 together with the signal S1 to obtain a signal S3; and the 2nd monostable multi-vibrator 17 is triggered to differentiate it through a differentiating circuit 18, obtaining a signal S4. This signal and signal S1 are applied to an NOR gate 19 together with blanking pulses from a terminal 20 to discriminate the occurrence of defect, and a multivibrator 21 is triggered by the results S5 to obtain an output Q3. The Q3 is delayed synchronously through FFs 22-24 to obtain discrimination outputs at terminals 25 and 26. A correcting circuit is controlled by both outputs to correct the defect. |
