Sony Corporation

Sadao Hosoi

Masayuki Takano

Yuichi Matsushita

A video tape recording/reproducing apparatus for reproducing video signals recorded in successive parallel tracks on a magnetic tape which is adapted to be longitudinally advanced, includes first and second magnetic heads movable in a direction generally along the tracks for reproducing signals recorded therein, and first and second bi-morph leaves for mounting the magnetic heads and being operative to deflect the first and second heads, respectively, in a direction transverse to the direction along the tracks. During the scanning operation by the respective heads, the first and second bi-morph leaves are supplied with a dithering signal for wobbling the heads transversely with respect to the longitudinal direction of the record tracks, a tracking error signal to correct deviations of the head trace from the tracks to be scanned and a slant angle correction signal to correct any inclination tracking error of the first and second magnetic heads. During the non-scanning operation by the heads, a phase error correction signal is supplied to the bi-morph leaves for deflecting the magnetic heads to accurately scan the beginning of the tracks. When the longitudinal speed of the magnetic tape exceeds, in the forward direction, a speed of 2.5 times the recording speed and, in the reverse direction, a speed of 0.5 times the recording speed, an offset signal forming circuit produces an offset signal which is supplied to the bi-morph leaves during the non-scanning operations of the magnetic heads to further deflect the heads by one track pitch in the negative and positive directions, respectively, so as to maintain the operation of the bi-morph leaves in the linear operating range thereof whereby to increase the ramp of possible tape reproducing speeds to direction, 3 times the recording speed when reproducing in the forward direction, and to the recording speed when reproducing in the reverse direction.

Head tracking control system for a helical scan VTR

In a video tape recorder which employs a rotary magnetic head secured on a deflectable device, such as a bi-morph leaf, to dynamically perform head tracking during reproduction of previously recorded tracks regardless of the tape transport speed; the height of the magnetic head is detected during recording to produce a feedback control signal which electrically adjusts the height of the magnetic head by deforming the bi-morph leaf to overcome hysteresis deflection of the bi-morph leaf so that the magnetic head is returned to and maintained at a normal height during recording.

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Atsugi, Japan

Sadao Hosoi