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Title:
DISK SUBSTRATE, METAL MOLD FOR MOLDING THE SAME, AND OPTICAL DISK
Document Type and Number:
Japanese Patent JPH09180251
Kind Code:
A
Abstract:

To assure a sufficient printing display part without flawing even being stacked, by transferring the information patterns inscribed on a stamper surface, cutting unnecessary materials to be molded, forming stack ribs on one surface and smoothing the opposite surface.

The surfaces of metal mold sections 1, 7 on a moving side and stationary side are fitted and positioned to each other. A cavity 12 for forming a disk substrate is formed between the stamper 4 on a mirror-finished surface plate 2 on the moving side and a mirror finished surface plate 8 on the stationary side. The material to be molded in a molten state is injected from the center of a sprue bushing 9 to the outer peripheral side from the center of the cavity 12. The information patterns on the surface of the stamper 4 are transferred when the material to be molded is cooled. The unnecessary material to be molded is thereafter cut by a stationary side bushing 10 and a cut punch 6 and the metal mold sections 1, 7 on the moving side and the stationary side are parted. The disk is then taken out. At this time, the stack ribs are formed in the non-recording region of the one surface and the other surface is smoothed. Even if, therefore, the disks are stacked, the disks are not flawed and a sufficient printing display part is assured on the smooth surface.


Inventors:
MARUYAMA HARUHISA
MOTOKAWA MASAAKI
HANZAWA SHINICHI
Application Number:
JP35010695A
Publication Date:
July 11, 1997
Filing Date:
December 22, 1995
Export Citation:
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Assignee:
PIONEER ELECTRONIC CORP
PIONEER VIDEO CORP
International Classes:
B29C45/26; B29D17/00; G11B7/24; G11B7/26; B29L17/00; (IPC1-7): G11B7/24; B29C45/26; G11B7/24; G11B7/26