Abstract: To prolong the useful life of a diamond guide element which serves to guide a transducer and which is provided with a contact surface via which the element in use bears against the surface of a record carrier while the carrier moves relative to the element, the element is constructed so that the direction of such relative movement corresponds to a high wear resistance direction of the diamond, and the contact surface thereof is periodically ground in an opposite direction in which it has a lower wear-resistance.

Abstract: A playback device for disc-shaped record carriers containing video signals stored in the grooves thereof which includes an arrangement which, in response to an applied power pulse, displaces the pickup, during playback, by a number of groove widths transversely to the direction of the groove.

Abstract: In a recording or playback system in which information is stored along a spiral track on a flexible record carrier foil which rotates at a high velocity on an air cushion above a stabilization surface, and playback is to be effected according to the pressure sensing technique, the adverse effects of static electrical charges which can be created when frictional contact occurs between the foil and points on the stabilization surface are eliminated by providing the stabilization surface with a grounded electrically conductive region in the vicinity of the path followed by a signal transducer along a radius of the foil plane as it traces the sprial track and by causing the foil to be closer to the conductive region than to the mass of the transducer.