PURPOSE: To sharply simplify a signal processing system at the writing side, and to reduce the cost of the titled device, by efficiently using signals, such as clock information, address information, etc., formed at the reading out side, as signals of the writing side.

CONSTITUTION: A reference video signal REF.S added to a terminal 6 is supplied to a synchronizing separator circuit 35, and a horizontal synchronizing signal REF.H and a burst signal REF.B are taken out. The burst signal is added to a clock generator 7 at the reading out side, and a reference subcarrier REF. SC and a readout clock R.CK are formed. The reference horizontal synchronizing signal REF.H is supplied to a line judging pulse generator 38 installed to a sequence controller 5, and a line judging pulse R.OE which is inverted in phase at every horizontal line is formed. The reference subcarrier REF.SC and the line judging pulse R.OE are also supplied to the writing side, and a write clock W.CK and a writing side line judging pulse W.OE are obtained at the writing side based on them.