| 摘要 |
PURPOSE:To improve quality control, yield and the efficiency of product control after sales by recording control information such as manufacturing conditions magnetically in unused areas of a magnetic disc. CONSTITUTION:Control information recording bands 13, 14 formed widely and rectangularly to the diameter direction of the magnetic disc 1 are included in the unused areas 3, 5 respectively. The control information such as the manufacturing date, lot No., manufacturing No., and manufacturing conditions of the magnetic disc 1 is magnetically recorded in the control information recording bands 13, 14. Consequently, the control information in each floppy disc can be read out from the control information recording bands 13, 14 by mounting the magnetic disc 1 on a retrieving driving device if necessary. Since control information recording bands 15, 16 can be formed concentrically in the unused areas 3, 5 respectively, the bands 15, 16 perform the same function as the bands 13, 14. Thus, the efficiency of quality control and product control can be improved. |
