| 摘要 |
PURPOSE:To reduce re-recording effects and to attain a high erasing rate, by keeping the widths of >=3 gaps formed at a cavity part of a magnetic core equal to each other or increasing them in the advancing direction of a recording medium and forming the width of the final gap in >=20mum. CONSTITUTION:Two spacers 5a, 5b made of a magnetic substance are provided to a cavity (l) of the magnetic core 4 to form three gaps g1, g2 and g3. The widths of the gaps g1, g2, g3 are formed to be equalized or to be increased in the advancing direction of magnetic recording medium. In deciding the width of the gap g3 formed at the exit side of the recording medium in >=20mum, the erasing rate being the same or more than that of erasing heads for conventional high coercive force magnetic recording media is obtained. Since the gaps g1, g2 are operated for the erasion and the gaps g2, g3 are operated for the prevention of re-recording, the high erasing rate is obtained, inexpensive core materials having less temperature rise and power consumption are used. |
