| 摘要 |
PURPOSE:To reduce the even-order distortion which is generated when a magnetic tape is reproduced, by magnetizing with polarization the tape rubbing surface so that the magnetic field intensity is gradually reduced in the tape traveling direction and dividing several poles counted from the final pole into magnetized and unmagnetized parts in the track width direction. CONSTITUTION:The rubbing surface of a magnetic tape 40 is magnetized in five N and S poles, for example, so that the magnetic field intensity is gradually reduced in the tape traveling direction (an arrow B). Then three poles counted from the final pole are divided into a magnetized part and an unmagnetized part (oblique lines). In such a way, a permanent magnet erasing head main body 50 is formed. A dummy head 60 is united the main body 50 to one body. In such a constitution, two regions having opposite polarities to each other exist within a track width in terms of DC residual magnetization with 1:1 ratio obtained between both regions. Thus the even-order distortions are eliminated with each other. As a result, the even-order distortion can be reduced when a magnetic tape is reproduced. |
