| 摘要 |
PURPOSE:To remove phenomena such as a flicker of a screen, black sinkage and white float by stabilizing the black level of a picture by improving the method of driving the vertical transfer part of pickup elements in a solid-state pickup unit using CCD pickup elements. CONSTITUTION:In a period from when electric charges are transferred from the final photodetecting element of one field with vertical transfer pulses 34 until when the transfer of the next field is started with the same pulses 35, the same pulses 36 are continuously applied without interruption to race a vertical transfer part. In this case, an output is generated due to the dark current of the vertical transfer part. Even when video signal 37 obtained in this way is clamped by a clamping circuit in terms of its signal part providing optical black, a difference in level between signal 40 providing optical black and signal 41 of the dark current of the vertical transfer part is extremely small, so that the clamped image will never vary in black level. |
