Random noise generation mechanism for a CCD imager with an incomplete transfer-type storage diode

A random noise for a CCD imager with an incomplete transfer-type storage diode is theoretically and experimentally discussed. The theoretical result based on the Fermi-Dirac distribution function is in good agreement with the well known experimental result as a "kTC" noise, which is equal to the square root of kTC/2. It is also shown that the random noise in the storage diode is dependent on the amount of the signal charge, and can be reduced for the small signal charge. Moreover, a small signal reset operation (SSR operation) is newly proposed to suppress the capacitive-image-lag and larger random noise. The reproduced image with the high signal-to-noise (S/N) ratio is obtained for a STACK-CCD imager with the small signal reset operation.