| 摘要 |
<p>PURPOSE:To prevent crosstalk from being caused by arranging a short ring or unused annular coil between annular coils in use for either of the 1st and the 2nd recording formats. CONSTITUTION:Three grooves with constant width are cut concentrically in the reverse surface of a rotary core 22R and the top surface of a fixed core 22S; and short rings 24 and 25 are provided in the center grooves, the 1st annular coils 261 and 271 are embedded in the outside grooves, and the 2nd annular coils 262 and 272 are set in the inside grooves. Further, four grooves with constant width are cut concentrically in the reverse surface of a rotary core 23R and the top surface of a fixed core 23S; and the 5th annular coils 301 and 311, the 3rd annular coils 281 and 291, the 6th annular coils 302 and 312, and the 4th annular coils 282 and 292 are embedded in those grooves in order from the outer peripheral sides to the inner peripheral sides. The respective annular coils and short rings 24 and 25 are positioned opposite each other similarly to the annular coils 261 and 271.</p> |
