A tracking-error correcting system in a rotary head magnetic recording and reproducing apparatus in which reproducing magnetic heads are mounted on a respective bimorph leaf having piezoelectric elements so as to be movable in the direction of the axis of rotation. The piezoelectric elements are controlled by a control voltage which is produced by adding a signal from an auto-tracking circuit and a signal from a triangular wave generating circuit. In a reproducing mode at a tape speed which is different from a tape speed in recording mode, this system activates the auto-tracking circuit when the control voltage level is within a limited range which is detected by a control voltage detector. Also, this system stops the auto-tracking circuit during a transition period when the reproduction mode changes.
In an information signal reproducing apparatus of the kind reproducing an information signal from a tape-shaped recording medium on which pilot signals of four different kinds having different frequencies are cyclically recorded in rotation along with the information signal, reference signals of four different kinds which correspond to the pilot signals of four different kinds and are generated one after another in a switch-over cycle to be used for tracking control together with these pilot signals. The reference signals are arranged to be generated one after another in a switch-over cycle which differs from the normal switch-over cycle during a specific period following change-over of the tape-shaped medium moving speed from one speed to another.
A system to improve image quality during shuttling of a video tape in a record and playback machine of the type in which each image field is recorded on one or more tracks on video tape. The system includes an offset signal source coupled to a displaceable mechanism during shuttling to provide relative displacement between a reproduce transducer and a video tape to cause the transducer to cross tracks of recorded information irregularly, thereby providing frequent updating of substantially all regions of an image field by information stored on the tape.
A control circuit for a helical scan playback, in which a rotary head is moved transversely by a varying amount. The transverse movement can be either a multi-valued tracking position error correction signal or a saw-tooth waveform, effective during a location data strip, for compensating for the fast movement of the tape during a scan operation.
In a helical-scan magnetic-tape apparatus having a scanning unit (102) comprising two diametrically opposed rotatable magnetic-head units (113, 114) which are movable over an actuating distance (A) in two opposite directions (r.sub.1, r.sub.2) by means of actuators (117, 118), the magnetic-head units, with the actuators not activated, are situated at a distance (X) from each other which is smaller than or equal to twice the actuating distance (A). During fast tape transport in a direction opposite to the tape transport direction with which information has been written in tracks on the magnetic tape each magnetic-head unit reads other tracks than those it would read during normal tape transport and/or the read sequence of the tracks is changed.
A double azimuth four-head drum may be made to be jointly usable in a digital VCR and VHS-VCR. A piezoelement is respectively installed between the head drum and the first standard play channel head and the first extended play channel head, and a switch is coupled to the piezoelement to apply a control voltage thereto.
