| 摘要 |
<p>PURPOSE:To control ensure the coincidence automatically between the scanning locus of a rotary head and the recording track of a tape, by utilizing the outputs of 4 rotary heads having about 90 deg. angle space secured among them and with the same gap angle secured between the heads which are opposite to each other. CONSTITUTION:The 4 rotary heads 1A-1D are provided to a tape guide drum 2 with a 90 deg. angle space secured to each other and rubbs a magnetic tape 3 wound around the circumference surface of the drum 2 with a >=270 deg. winding angle. A pair of rotary heads 1A and 1C has a gap angle different from that of a pair of heads 1B and 1D to a line orthogonal to the scanning direction. These rotary heads are successively switched in order of the earlier coincidence of the gap angle secured with a recording head in order to obtain a reproduced output. Then the outputs of the two rotary heads are extracted among other heads from which no reproduced output is extracted. The relative positional relation is controlled between the scanning locus of the rotary head and a recording track from the mutual level relations among these rotary heads.</p> |
