PURPOSE: To execute high speed charge transfer with small power consumption, by transferring signal charge with stepwise potential and sequentially and selectively transferring signal charge at each element.

CONSTITUTION: Signal carriers generated photodiodes 28-a∼38-c due to incident light are stored in each photodiode. After a prescribed time, a transfer pulse is applied to an AND gate of the 1st element column from a line address scanning circuit 44 and the signal carriers are transferred from columns 28-a∼28-e to corresponding vertical signal transfer paths 39∼43. Each carrier is transferred to corresponding transfer stage of a CCD register 56. The signal charges of the 1st column transferred in parallel with the register 56 at the same time are horizontally transferred in serial and a signal generated at the columns 28-a∼ 28-e is picked up from an output circuit 57 as a time series signal. Thus, the operation like this is repeated and signals generated at all the photodiodes are picked up.