| 摘要 |
PURPOSE:To shorten the servo information recording time and reduce the production cost, by connecting servo signal recording circuits and magnetic heads for servo whose number corresponds to the number of magnetic double layer disc faces and recording servo information simultaneously. CONSTITUTION:A head disc assembly constituted with magnetic double layer discs 22-26 and magnetic heads 41-50 is set onto a mechanism part 57 for index and reference clocks consisting of a single layer magnetic disc 27, heads 29 and 30 for reference clock, and a head 40 for index, and they are connected to the same revolving shaft 28. Low-frequency reference clock signals of even and odd tracks are reproduced by heads 29 and 30 for reference clock. These reference clock signals are used, and servo information is recorded simultaneously by servo signal recording circuits and servo signal recording magnetic heads which correspond to magnetic double layer disc faces of the head disc assembly respectively. |
