| 摘要 |
PROBLEM TO BE SOLVED: To provide a glass substrate for a magnetic recording medium and a magnetic recording medium which enables a magnetic head to be stably operated during LUL (Load Unload). SOLUTION: In the glass substrate for magnetic recording media to be used for the doughnut-like magnetic recording medium which has an outer peripheral end face and an inner peripheral end face concentric with a principal surface having a flat part and has a freely rotating hub of a spindle motor which constitutes an information recording device, fitted to and inserted through a hole formed by the inner peripheral end face, and is used in a magnetic recording medium fixed to the hub and used in a LUL system, the roundness of a circle formed by the outermost periphery of the outer peripheral end face is≤4μm. COPYRIGHT: (C)2008,JPO&INPIT
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