PURPOSE: To attan accuracy and ease of demodulation/reproduction of a digital signal by inserting a clock line signal and a data synchronizing signal to a head position of each field as a field synchronizing signal.

CONSTITUTION: A horizontal scanning line constituting one field in a video format signal is divided into plural blocks, and digital data of prescribed information are inserted to the 1st block. A data synchronizing signal deciding the synchronizing timing and a clock signal in synchronizing with the clock timing of the digital data are inserted to the 2nd block. A control signal processing the recording information of the 1st block is inserted to the 3rd block. The data synchronizing signal and clock signal are extracted, the word synchronism and bit synchronism are performed then the digital data information is reproduced.