| 摘要 |
PURPOSE:To prevent an identification unable due to a peeling, a stain or the like by previously applying an identification symbol to at least one of an internal periphery spacer and an external periphery spacer. CONSTITUTION:A disk 1 consisting of two disks 1, 1, the internal periphery spacer 2 and the external periphery spacer 3 has respective one surface on which a spiral or concentric extremely fine signal groove 4 are disposed. In order to protect the signal groove and form the both surface disk, the signal grooves are respectively internally directed and sealed in a clean environment by the internal and external spacers 2, 3 not so as not to interface mutually. A production process or information required for a user is applied to the internal and external spacers 2, 3 by sealing or press fitting and printing or the like and in a sealing process, the identification information of the disk is obtained. Thereby, a labeling process or a disk printing process is eliminated to obtain the disk having no influence of dust or a flaw.
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