PURPOSE: To make a transmission circuit and a transmission line in one, to reduce a radiation noise on the transmission line, and to perform phase compensation by employing PLL constitution by D control.

CONSTITUTION: A counter 11 divides the frequency of the timing pulse signal fc2, generated by a timing pulse generating circuit 10, into four. The video signal from a CCD 1 has a reset noise removed through a CDS circuit 2 and is sent to a mixing circuit 12 as a video signal after its CCD clock component is removed through an LPF. In its horizontal blanking period, timing pulses 1/4fc2 are inserted, so the switch of the mixing circuit 12 is connected to a timing pulse signal side at the horizontal blanking part except the optical black part of the video signal in the horizontal scanning period. Consequently, the video signal and timing pulse signal are mixed in a time series. This mixed signal is sent to a CCU side by a cable driver circuit 3 through the transmission line 4. Consequently, the radiation noise from the transmission line is reducible.