Diskette incorporating permanent magnet generator with low leakage flux

摘要

In a diskette, such as a 3.5'' floppy disk, having adjoiningly a permanent magnet generator and a space for inserting a memory card with a magnetic stripe, the affection of leakage magnetic flux from the generator permanent magnet to the memory card and another floppy disk that may be put in the neighborhood of the diskette is substantially eliminated and the generator output is increased. A magnetic shield is disposed only at the portion corresponding to the magnetic stripe of the memory card on a generator housing or a partition between the generator permanent magnet and the memory card space. A magnetic shield ring with a diameter substantially equal to or larger than the outside diameter of the permanent magnet is fixed or pasted on one side end of the rotor permanent magnet adjacent to one of the ends of the diskette case.