| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for using a plurality of non-contact type information recording media in an overlapping fashion by using a shield sheet which combines magnetic field line shielding parts of a size smaller than a magnetic field line attenuation plate in a storage case for non-contact type information recording media. <P>SOLUTION: The shield sheet 10 comprises a shield material (a magnetic field line attenuation plate) 11 consisting of a perfect conductor such as copper, iron, and aluminum, or a diamagnetic material, and a ferrite material (a magnetic field line shielding part) 12 consisting of a magnetic material such as a ferritic core attached to the front and the back of the shield material 11. The ferrite material 12 is smaller in area than the shield material 11, and is arranged so as to be always housed inside the shield material 11. That is, the outer circumferential margin of the ferrite material 12 does not protrude beyond the outer circumferential margin of the shield material 11, but is always retracted inside the outer circumferential margin of the shield material 11. <P>COPYRIGHT: (C)2007,JPO&INPIT |
