Abstract: This invention relates to a system for optically playing back recorded signals from a recorded medium on which signals of images or sounds are continuously recorded so as to constitute a signal recorded line or signal track. In play-back the images or sounds are optically recognized by the width-change of the signal recorded line. A narrow light beam for the play-back is deflected at a predetermined frequency in the direction perpendicular to the signal recorded line, i.e. in the direction of the width of the signal recorded line, in order to perform the optical scanning. The narrow light beam which is reflected or transmitted on the recorded medium surface reaches photo-sensitive elements such as photo-diodes.