| 摘要 |
PURPOSE:To make it possible to simultaneously mold pit trains for tracking on both sides by a method wherein molding is done under the conditions that the inner edge of each stamper, which is held on the surface of a mirror platen is pinched by the outer peripheral flange of a fitting ring, while its outer peripheral edge is pinched by the flange of a press ring. CONSTITUTION:Each mirror platen 3 (or 15), onto which a stamper 7 (or 18) is mounted, is fixed through a sleeve 4 (or 16). Further, the inner peripheral edge of the stamper is pinched by the annular flange 8a (or 17a) of a fitting ring 8 (or 17), which is fitted onto the outer peripheral surface of the sleeve and, at the same time, the outer peripheral part of the stamper is pinched by the flange 9a (or 19a) of an outer peripheral press ring 9 (or 19) for molding. Accordingly, pit train signals can be produced by one process on both the sides of a disc substrate. In addition, the parallelism between the mirror platen and the sleeve face is preferably obtained by highly accurately finishing the large diametral part 4a (or 16a) of the sleeve and fitting said part normal to the mirror platen. And, the formation of a tapered stepped part 12 (or 21) on the opposed surfaces of the outer peripheral press rings of the stampers is preferable as the aligning means of the mirror platens on a fixed side 1 and on a movable side 4. |
