| 摘要 |
<p>PURPOSE:To reduce the rotation unevenness of a rotary head by a method wherein a frequency-generating ring-shaped magnet is arranged in such a way that the rotation locus of its outer circumference is situated at the inside with reference to the first outer circumferential pattern of a frequency-generating pattern coil. CONSTITUTION:A frequency-generating ring-shaped magnet 58 is arranged in such a way that the rotation locus of a chamfered end part 81 at its outer circumference is situated at the inside with reference to the first outer circumferential pattern 69 of a frequency-generating pattern coil and that the rotation locus of a chamfered end part 82 at its inner circumference is faced with the axis-center facing pattern 67 of the frequency-generating pattern coil. At the frequency-generating pattern coil, a change in a rotation magnetic flux is changed to an electric signal irrespective of the rotation eccentricity of the frequency-generating ring-shaped magnet 58. Consequently, the rotation unevenness of rotary heads 42, 43 is reduced, a magnetized track recorded by using the rotary head 42 is set to a stable state that a recording position is not changed, and a replay signal jitter from the rotary heads can be reduced.</p> |
