| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably record/reproduce by providing a groove placing between from a lower end to an upper end of a notched part for projecting a video head and with a width size smaller than the height size of the notched part on an outer peripheral surface of a rotary drum. SOLUTION: A rotary head drum device 1 of a helical scan system is constituted of the rotary drum 2 projecting plural video heads 5 on the outer peripheral surface 2a and a fixed drum 4 rotatably supporting the drum 2 and forming a tape lead 4b running a magnetic tape 6 around the outer peripheral surface 4a. At this time, the groove 7 placing between from the lower end to the upper end of the notched part 9 for projecting the video head and with the width size smaller than the height size of the notched part 9 is provided on the outer peripheral surface 32a of the drum 2. Then, magnetic dust omitted from the tape 6 due to that the head 5 rotating at high speed is in contact with the tape 6 and foreign matters, etc., on the magnetic tape surface are housed in the groove 7 not to be stuck to the outer peripheral surface 2a. Thus, a recording signal on the tape 6 isn't erased, and stable recording/reproducing is performed.</p> |
