| 摘要 |
PURPOSE:To attain reproduction and recording at the same time by providing three sets of video head couples on a rotary drum of the helical scan system so as to use sequentially them as reproduction, erasure and recording in the preceding order in the direction of drum turning direction. CONSTITUTION:The recording heads Ha1, Ha2, erasure heads Ha2, Hb2 and reproduction heads Ha3, Hb3 using one couple as one set arranged equally on the circumference of the rotary drum 1 are provided. The reproducing head Ha3 traces in the direction of arrow HD and picks up a signal on a magnetic tape 2. The erasure head Ha2 whose video width W2 is slightly broader than that of the recording head Ha1 is traced while its lower end lines are arranged so as to erase widely the fields Ta, Tb of video signals on the magnetic tape 2 finished for reproduction. The recording head Ha1 writes a new video signal while the lower end is arranged to the field after erasure. The reproducing head Ha3 performs reproduction and the recording head Ha1 performs recording at the same time.
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