| 摘要 |
PURPOSE:To simplify the retrieval of a desired storage medium out of many media, by recording an index relating to the recording content of a main data recording area to other areas excluding the main data recording area with a visual character pattern. CONSTITUTION:Long holes 21, 22 are formed along the radial direction of a disc main body 1, a space having a transparent window is provided along an index recording area 13 and magnetic powder is sealed in the space. Magnetic character pattern is formed in the area 13 with a plurality of index recording heads toward the radial direction of the main body 1. Since the magnetic powder of the space of the case 2 is absorbed to the magnetizing section of the area 13 with the main body 1 contained in the case 2, the character pattern is displayed visually. |
