| 摘要 |
PURPOSE:To read accurately information recorded on a magnetic recoding medium by arranging a reproducing head and a DC degaussing head so that an up/down asymmetric peak shift caused by a magneto-resistance element is canceled by an up/down asymmetric peak shift caused by degaussing. CONSTITUTION:When a degaussing current is impressed to a degaussing coil 92 as shown by an arrow I, a magnetic core 91 is magnetized to the polarities N and S as shown in a figure, and consequently a magnetic recording medium 3 is degaussed on DC basis. The magnetism state of the magnetic recording medium 3 at this time is as shown by a simulated cross figure and residual magnetism is given by the DC degaussing in the opposite direction M of the traveling direction T of the magnetic recording medium 3. Then, an area P magnetized in the opposite direction of the traveling direction T of the magnetic recording medium 3 and an area Q magnetized in the same direction are formed by the recording of information. When a magnetism inversion area changes from Q to P, a plus magnetism inversion signal is obtained and when it is changes reversely, a negative signal is obtained; while the area Q is narrowed down in magnetism area as shown by a dotted line, the area P is in a magnetism saturated state and there is no influence of residual magnetism. |
