Method of compensating for the integration of light by the vertical shift registers in an interline transfer charge coupled device

摘要

A digital camera calibrates its exposure metering to compensate for charge accumulated in the vertical shift registers of an interline transfer CCD due to light reaching the shielded shift registers. The camera performs a short exposure, optionally suppresses the usual shift of charge from sensor sites on the CCD into the vertical shift registers, and then reads the contents of the vertical shift registers. An average digital pixel brightness value is recorded for this trial photograph. The average digital pixel brightness value of the trial photograph is removed from the digital pixel brightness values in subsequent light metering photographs. Optionally, the average digital pixel brightness value of the trial photograph is removed from the digital pixel brightness values in a subsequent final photograph.