| 摘要 |
PURPOSE:To prevent the deterioration of picture quality by providing a press contact part having a curvature in a running direction of a metal group medium and an output shoulder having a notch parted from the metal group medium from the prolonged line of the curvature of the press contact part so as to improve the spacing loss. CONSTITUTION:The press contact part 16a is a region shown in hatched lines from a part 15a of an incoming core 12c to a part 15b of an outgoing core 12d and a proper curvature R1 is provided to apply desired recording/ reproduction and smooth running with the metal group medium 11 in the running direction 11a of the metal group medium 11. Then the region from a part 15a on the incoming core 12c to the incoming end 12e among non-contact region with the metal group medium 11 is the incoming shoulder 16b. The region from the part 15b on the outgoing core 12d to an outgoing end 12f is an outgoing shoulder 16c, which is provided with a notch 16e so as to be parted from the medium 11 from the prolonged line 16d of the curvature R1 of the press contact part 16a in the running direction 11a of the medium 11. |
