| 摘要 |
PURPOSE:To improve the surface smoothness of a magnetic layer and to reduce the variance of output level by leading a base film into and out a magnetic field formed by revolving a magnetic field generating means or shifting endlessly in locus said means with revolution so that the magnets of the same polarity are set opposite to each other in the vertical direction. CONSTITUTION:Roll magnets 7 and 8 for orientation are revolved at the same speed in the directions shown by arrows A and B. Many magnets 71 and 81 are set so that the same polarities are always set opposite to each other on the basis of a base film 2. As a result, a magnetic field parallel to the lengthwise direction of the film 2 and another magnetic field parallel to the width direction of the film 2 and another magnetic field parallel to the width direction of the film 2 are applied repetitively at any position of a coated film 6 on the film 2 and within the surface of the film 6. Then the orientating direction is corrected to the magnetic powder particles orientated in the lengthwise direction of the film 2 while a magnetic coating material is applied. As a result, the magnetic powder particles in the film 6 have no orientation, and the square forms are almost equal to each other between the lengthwise and width directions. Such a film is dried up and then blanked into a circular shape to obtain a magnetic disk. Thus a considerable variance of the output level is eliminated with this magnetic disk when the record/reproduction is carried out in the circumference direction of the disk. In such a way, the electromagnetic conversion characteristic is improved.
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