Charge transfer device having control means for its photoelectric conversion characteristics

An operation system to control the photoelectric conversion characteristics of a charge transfer device comprising a semiconductor substrate provided with a plurality of electrodes for carrier integration and transference, integration means for integrating within an integration period the carriers produced in said substrate in increasingly corresponding relationship to the intensity of light incident into said substrate by applying an integration voltage to said electrodes for carrier integration, and transfer and readout means for transferring the integrated carriers by applying when carrier transferring is performed, a transfer voltage to said electrodes for carrier transference and sequentially reading out the transferred carriers as video signals, characterized in that it further comprises means for applying a first integration voltage having a prescribed level to said electrodes for carrier integration during a prescribed length of initial period of said integration period, and means for applying during the remaining integration period a second integration voltage having a level higher than the first integration voltage level at the terminating time point of said initial period to said electrodes for carrier integration.