Abstract: A method of clocking an image sensor which eliminates well bounce effects caused by global current flow in large image sensors during frame readout and line transfer is described. During charge transfer operations in which voltages are applied to VCCD gate contacts that are adjacent to the photodiodes, a compensating voltage may be applied to the lightshield that is associated with, and at least partially formed over the photodiode. Depending on polarity, the compensating lightshield pulse allows holes to locally flow from under the VCCD gates to the photodiode P+ pinning region or vice-versa, and in such a manner to eliminate the global flow of hole current. Lightshields may also be biased during electronic shuttering operations.

Abstract: A method of clocking an image sensor which eliminates well bounce effects caused by global current flow in large image sensors during frame readout and line transfer is described. During charge transfer operations in which voltages are applied to VCCD gate contacts that are adjacent to the photodiodes, a compensating voltage may be applied to the lightshield that is associated with, and at least partially formed over the photodiode. Depending on polarity, the compensating lightshield pulse allows holes to locally flow from under the VCCD gates to the photodiode P+ pinning region or vice-versa, and in such a manner to eliminate the global flow of hole current. Lightshields may also be biased during electronic shuttering operations.