Matsushita Electric Industrial Co., Ltd.

Hideyo Shibata

Takayasu Yoshida

Shigeo Eshima

Ritsuro Kinoshita

Track thinning at an IN point of consecutive recording is prevented by doing a head-track one-edge coincidence tracking by using a head of a larger width than the track width. ATF control unit () makes a control during reproduction of pre-roll of consecutive recording according to a pilot signal out of the reproduction output from heads () so that centers of the heads () may scan the center line of the track. A positioning signal () during the control and a phase of HSW are detected by a detecting circuit (), and a desired phase having a predetermined advanced amount is set by a desired phase setting unit () and stored in a storage unit (). After this, a tracking method switching control unit () switches the tracking method into another by which a control unit () controls the difference in phase between the positioning signal () and the HSW to a desired value stored in the storage unit ().

Magnetic recording/reproducing device having position control

Video signals are recorded according to the number of tracks corresponding to the broadcasting system for each basic unit. When control signals are recorded on a magnetic tape in the longitudinal direction, the duty ratio of the control signals for every N tracks recorded for each basic unit has a value different from that of the duty ratio of other control signals. At the time when the magnetic tape is reproduced CTL signals are obtained by forming waveforms of the reproduced amplified outputs by means of a waveform formation unit . A CTL signal duty ratio determination unit detects the border of a frame in accordance with the duty ratio. A broadcasting a system determination unit determines the broadcasting system based on the counting result of the CTL signals during one frame that has been counted by the CTL signal counting unit . Thereby, it is made possible to record and to reproduce programs of a differing broadcasting system by using an information recorder/reproducer of which the number of revolutions of the rotating cylinder and the transfer speed of the magnetic tape are the same.

Information recorder/reproducer

In a magnetic recording and reproducing apparatus for reproducing a video signal recorded on a video track of a magnetic tape by pair of magnetic heads arranged in a rotation drum so as to oppose to each other at an angle of 180 degrees, while rotating a capstan for moving the magnetic tape in the longitudinal direction, a memory controller controls the reproduced video signal to be written into and be read out from two memories, each of which stores a video signal of at least one field. Then, a quality of image judgment circuit judges a part of the reproduced video signal having a quality of image higher than a predetermined threshold quality level, among a plurality of parts of the reproduced video signal obtained through scan of a pair of magnetic heads. In a slow-motion reproduction, the memory control circuit controls the part of the reproduced video signal having the higher quality of image to be written into one of the two memories, whereas the memory control circuit simultaneously controls a further reproduced video signal to be read out from another one of the two memories.

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Hirakata, Japan

Hideyo Shibata