PURPOSE: To satisfactorily process transfer efficiency and a dark current, and to make a device small-sized, by making a converted digital value circulate in a transfer register of a solid image pickup element.

CONSTITUTION: When a switch 18 is connected to a contact (a) side, a picture image signal irradiated to each picture element of a solid image pickup element 1 is converted to a digital value of 4 bits and is held in the element 1. Subsequently, when a transfer pulse is supplied to the element 1, a digitized picture image signal of one photographing surface circulates in a transfer register of the element 1, and the digitized picture image signal is outputted continuously from an output terminal 14. Accordingly, when a picture image signal recording device 32 is selected by a selecting switch 19, the digitized picture image signal is recorded in a selected recording device. Also, in case of reproducing a picture image signal in the device 32, the element 1 is operated by connecting a picture image signal outputting device to the output terminal 14 of the register by the switch 19. In this way, the picture image signal circulates by the transfer register and is output from the terminal 14.