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US 4,900,380 AGranted
Process for producing information recording medium
AssigneeFuji Photo Film Co., Ltd.
InventorHideki Matsuzawa
Life of this patent
Estimating the term…
Abstract
A process for producing an information recording medium such as an optical disc comprises the steps of: putting a disc-shaped resin film having a hole at its central part upon a surface of a recording layer-side of a disc-shaped resin substrate having a hole at its center; and joining the resin film to the resin substrate by thermal welding in an outer-side non-recording zone of the substrate and by ultrasonic welding in an inner-side non-recording zone of the substrate.
Claims3
A process for producing an information recording medium which comprises the steps:
- putting a disc-shaped resin film having a hole at a central part thereof upon a surface of a recording layer-side of a disc-shaped resin substrate having such a structure that a hole is provided at a central part thereof, an inner-side non-recording zone is provided around the pheriphery of the hole, an outer-side non-recording zone is provided inside the outer periphery of the substrate and a recording layer is provided between said inner-side non-recording zone and said outer-side non-recording zone on the substrate;
- and
- joining said resin film to said resin susbstrate by thermal welding in the outer-side non-recording zone of the substrate, and by ultrasonic welding in the inner-side non-recording zone of the substrate.
Dependencies are inferred from the claim text.