| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform restoration operation to an original reading layer, even when an impact is generated in a recording medium, and to provide an electronic device which houses the recording medium. <P>SOLUTION: In the disk-like recording medium wherein a through-hole 2A for rotational driving is formed in a center part, a plurality of spiral hologram layers 3 are formed in the thickness direction of the recording medium, at a prescribed interval in a multilayer state; each of the spiral hologram layers 3 is constituted of a hologram for recording information; and layer detection information is recorded in a hologram 4G on an inner peripheral side of each spiral hologram layer 3. <P>COPYRIGHT: (C)2010,JPO&INPIT |
