Is smear generated in pco CMOS cameras?
When an interline-transfer-CCD image sensor is read out, the generated charge carriers are transferred from the light sensitive part (photodiode) of a pixel to the shift register. This is located next to the photodiodes and acts like a potential bucket. As there is weak light sensitivity on these shift registers, they are shaded to prevent the additional generation of charge carriers.
When the charge transfer to the shift registers is complete, they are vertically shifted, row-by-row, to the horizontal readout line, which is then read out serially. This row-by-row vertical shifting is comparable to an endless conveyor belt. With every shift step, all registers are shifted by one register location, including those register rows that were previously drained from the image.
