A device for detecting the rotating phase of rotary magnetic heads of a video tape recording apparatus in order to synchronize the rotation of the rotating heads with the synchronizing signals recorded, or to be recorded on the video tape is disclosed. A magnet piece is positioned upon a rotating disc or drum carrying rotary magnetic heads adjacent to one of rotary heads, and detecting coils as a phase detecting elements are mounted upon mounts in such a way that they may be movable along the path of the magnet piece. One end of each of mounts disposed on a stationary drum, upon which is mounted the rotating disc or drum, extends beyond the outer periphery of the stationary drum and terminates into a toothed portion adapted for engagement with a pinion of an adjusting tool, so that the angular position of the detecting coil may be adjusted by rotating the adjusting rod. This adjustment may be accomplished from the exterior of the rotary head assembly while the tape is transported, so that an operator may immediately check the result of the adjustment over a monitor.
A device for transferring signals between itself and a record carrier tape, the device including a rotating head wheel disk, at least one head disposed on the rotating head wheel disk, a sensor and a signal emitter to indicate the position of the head wheel disk, the improvement wherein the signal emitter comprises two juxtaposed electrical conductors.
The invention concerns a videorecorder with a rotating head drum (KT) that has video heads (K1 & K2) with a magnetic tape (B) looped partly around them mounted on it, with at least one pulse generator (M) mounted on the head drum, with at least one sensor (S) that generates a head-shift signal that switches from one video head to the other, and with a control head (KK) for scanning the vertical-synchronization signal during playback. In the playback mode the time between the signal supplied to the sensor and the vertical-synchronization signal is measured and compared with a reference, and a criterion for controlling the position in time of the head-shift signal is derived from the comparison.
