Charge sweep operation for reducing image lag

摘要

A method and apparatus are disclosed for improving imager lag by using a charge sweep operation in which residual charge is swept out of the photodiode to reduce lag effects. The charge is swept out of the photodiode by activating the reset transistor a second time, substantially simultaneously with the activation of the transfer gate after the signal voltage V_sig is readout. A second embodiment sweeps charge out of the photodiode by activating a transistor electrically connected to the photodiode after the signal voltage V_sig is readout.