PURPOSE: To enable shutter operations of high speed without decreasing the resolution by a method wherein the period of opening an optical shutter is provided by the same period, before and after transferring accumulated signal charges.

CONSTITUTION: In an electron camera, a VH pulse is repeated in every field, and signal charges transfer from a photo diode to a vertical CCD within a pulse width Ts (1∼10μsec), in order to obtain an image signal of each field. With the terminal of the VH level holding period Ts as the center, a shutter is opened before and after it for TO/2. TO is set as approx. 1m sec, and, within the period of VH levels, the charges generated and accumulated in the photo diode for TO/2 of the first half are transferred to the CCD at the VH, then the charges for TO/2 of the latter half are transferred at the next VH 10 11, accordingly signals SA and SB are obtained from fields A and B. Since the output levels are coincident in the period of irradiation onto the both fields, they are equal each other. By this constitution, even when the high speed shutter operation for 1m sec is necessary, the signals of the both fields A and B can be outputted, and the decrease of resolution is not generated, therefore it can be applied to an electron camera.