| 摘要 |
PURPOSE:To improve the density of recording by a head having a simple constitution by combining a normal annular head with a two-layer film recording medium and restricting its gap length and vertically magnetized film thickness to respective specific values or less. CONSTITUTION:Data are recorded and reproduced on the two-layer film recording medium 13 obtained by forming a vertically-magnetized film 16 having <=0.25 mum thickness (t) on a high magnetic permeability layer 15 by using an annular magnetic head 11 having <=0.25mum gap length (g). In this case, the saturated magnetization of the vertically-magnetized film 16, vertical coercive force and the specific magnetic permeability of the high magnetic permeability layer are set up to 200-600emu/cc, 250-1,000Oe and >=500 respectively. A Co-Cr thin film is used as the vertically-magnetized film 16. Said constitution makes is possible to obtain high density recording of >=100 KBP1. Since the normal annular head and the two-layer film recording medium are practically used and their production technique is also established, the reliability is also high. |
