JPH0477510B

PURPOSE:To perform a part of picture signal processing at a circuit always operated at optimum speed by adding a train of CCD(Charge Coupled Device) newly at the front stage of a conventional CCD train for readout. CONSTITUTION:Electric charge accumulated in a photodetecting part train 1 is shifted to an additional CCD train 3 by opening a charge transfer gate 6 after completing image pickup. After that, a fast driving signal is supplied to a driving pulse supplying electrode 8, and accumulated charge in charge transfer devices b1-bn-1 in the additional CCD train 3 are outputted ot an electrode 5 for attracting charge, then, erased. Next, the signal supplied to the driving pulse supplying electrode 8 is stopped, and the charge shifted from charge transfer devices an-an+4 in the additional CCD train 3 are shifted to the CCD train 2 for readout by opening a charge transfer gate 7. The additional CCD train 3 erases unrequired charge out of next image information as stated above, and the photodetecting part train 1 accumulates following image information. By executing the operations of the photodetecting part train 1, the CCD train 2 for readout, and the additional CCD string 3 in parallel, it is possible to read out only the image information image-picked up by the phtodetectors an-an+4 to the outside at low speed.