| 摘要 |
PURPOSE:To prevent the deposition of foreign matter which becomes nucleus for head clogging by making the angle of notch assumed with a line perpendicular to heat gap junction line at the point where magnetic tape detaches from head core more than 10 deg. at the recording and reproducing. CONSTITUTION:The head 14 mounted to the outside circumference of the rotary cylinder 2 of the rotary head device of a VTR is so constituted that its front side 17 and rear side 18 are formed non-symmetrically and that the angle assumed with the line perpendicular to head gap junction line at the notch point 21 of the portion protruding from the rotary cylinder outside circumference 3 of the sliding part 20 with tape 12 on the rear side 18 is made more than 10 deg.. Hence, the head detaches from the tape 12 at the point where the curvature of the front face R of the head 14 changes sharply and the sliding contact pressure at that detaching point is maintained above a value at which it becomes unstable and therefore there is no more unstable sliding contact region and the deposition of foreign matter which becomes the nucleus for head clogging may be prevented. |
