| 摘要 |
PURPOSE:To reduce the pseudo output reproduced on the discontinuous surfaces by setting the length of a magnetic thin film in the gap depth direction at least at >=5 times as much as said gap depth. CONSTITUTION:A magnetic thin film 3 is formed toward a back gap 18 with the depth larger than the gap depth 17 of a magnetic gap 4. Thus the depth 17 is increased in case the discontinuous surfaces are considered as a pseudo gap and the most of the flow of a reproduced magnetic flux 15 is closed at the part of the depth 17. Thus, a magnetic flux 14 which interlinks a coil 13 as a reproduction output is reduced. In this case, the length of the film 3 is set at least at >=5 times as much as the depth 17 in this gap depth direction. Thus, it is possible to reduce the pseudo output reproduced from the discontinuous surfaces produced between the film 3 and a film forming surface.
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