The effects of smear on antiblooming protection and dynamic range of interline CCD image sensors

摘要

The effects of a smearing signal on the dynamic range and the amount of antiblooming protection of an interline CCD image sensor are presented. It is shown that there is a tradeoff between these two parameters, and that they are directly related by the amount of smear. These relationships are analyzed for both constant-integration time and constant-irradiance modes of operation. For the constant-irradiance model of operation it is shown that in order to maintain 90% of the maximum dynamic range and an antiblooming protection of 300*, the smear signal must be less than 0.037%. For the constant integration-time mode of operation, it is shown that in order to maintain 75% of a particular device's maximum dynamic range and the same amount of antiblooming protection the smear signal must be less than 0.0074%. It is also found in this mode that this relationship between antiblooming protection and the amount of linear dynamic range is exponential, and dependent on the antiblooming structure's nonideality factor and the individual photodetector's capacitance.