Optical disc and mold for manufacturing the optical disc
OwnerTetsuya Iida, Keiji Suga +2inventors
InventorsTETSUYA IIDA, KEIJI SUGA, TETSUYA IMAI, YOSHITSUGU ARAKI
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Abstract
A substrate of an optical disc is formed by injection molding. One of the surfaces of the substrate has a plurality of pits corresponding to information signals. The other surface has a plurality of dummy pits.
Claims6
An optical disc including a substrate formed by injection molding and having opposite surfaces wherein one of the surfaces has a plurality of pits corresponding to information signals, and the other surface has a plurality of dummy pits.
An optical disc including a substrate formed by injection molding and having an information recording surface and an information reading surface formed on opposite sides thereof, wherein the information recording surface has a plurality of pits, and the information reading surface has a plurality of dummy pits.
A mold for molding a substrate of an optical disc by an injection molding machine having a fixed mold and a movable mold for forming a cavity there-between, comprising:
- a first stamper having pits corresponding to information to be recorded on the optical disc and secured to one of the molds;
- and
- a second stamper having dummy pits for forming dummy pits on a surface of the substrate and secured to the other mold.
An injection molding machine for molding a substrate of an optical disc having a fixed mold and a movable mold for forming a cavity there-between comprising:
- a first stamper having pits corresponding to information to be recorded on the optical disc and secured to one of the molds;
- and
- a second stamper having pits on a surface of the substrate and secured to the other mold.
Dependencies are inferred from the claim text.