| 摘要 |
To maintain a maximum ratio of signal charge to background charge in a CCD image detector, a background level of illumination of the CCD is maintained at a minimum level consistent with adequate fast charge transfer. This is conventiently accomplished by varying the intensity of radiation from a source within the detector incident on the CCD in dependence upon comparison between an averaged video output of the detector and a reference signal characteristic of optimum illumination of the CCD. |
