A moving object 2 transferred by a transfer path 1 is detected by a position sensor 3 to generate a trigger pulse signal TRIG-IN of which pulse width can be adjustably set by a pulse width adjustable setting circuit 5 on the basis of a detection output of the position sensor 3 to deliver, to a CCD camera 10, modulated synchronizing signals T.G.-VD, T.G.-HD in which the trailing edge of the trigger pulse signal is caused to be timing of reference, which are generated in accordance with the trigger pulse signal TRIG-IN by a modulated HD signal preparation section 22 and a shutter control signal SHCLTL in which the leading edge of the trigger pulse signal TRIG-IN is caused to be timing of reference to allow it to carry out image pick-up operation of object for effective exposure time period corresponding to pulse width of trigger pulse signal TRIG-IN generated by the pulse width adjustable setting circuit 5, thereby making it possible to synchronize the image pick-up operation with a synchronizing signal of random period. In addition, continuous adjustable control of the exposure time period over broad range can be carried out.