Patent US6249779B1 successfully refreshed from Google Patents.
EP0341785A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical disc having an antiresonance ring
Assignee: Philips and Du Pont Optical Co BV
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Filing: 1989-05-05
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Granted: —
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Expires: 2009-05-05
Abstract
Abstract The optical disc has a sandwich structure comprising two parallel single discs (1, 2) which are located at some distance from one another, and which are interconnected by an inner spacer ring (4) and an outer spacer ring (5), an antiresonance ring (20) being provided in the space (19) bounded by the discs and the rings.
Inventors
- 👤 Fred Joseph Harper
- 👤 Rense Arie De Vries
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 02:34
CPC Classifications
G; G11; G11B; G11B25/00; G11B25/04; G11B23/00; G11B23/0014; G11B23/0021; G11B23/0028; G11B23/0035; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10584; G11B7/00; G11B7/24; G11B7/24015
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
104 words
An optical disc having a sandwich structure, comprising two parallel substrate discs which are located at some distance from one another, the substrate discs each comprising an optical structure on the sides facing one another and being interconnected by means of annular spacer elements, at least one annular spacer being provided around a centre hole present in both discs and at least one annular spacer being positioned at the outer edge of the substrate discs, characterized in that an antiresonance ring of an elastic material is provided between the annular spacer elements, which antiresonance ring is connected to the substrate discs on both sides.
Claim 2
Dependent Claim
104 words
An optical disc having a sandwich structure, comprising two parallel substrate discs which are located at some distance from one another, the substrate discs each comprising an optical structure on the sides facing one another and being interconnected by means of annular spacer elements, at least one annular spacer being provided around a centre hole present in both discs and at least one annular spacer being positioned at the outer edge of the substrate discs, characterized in that an antiresonance ring of an elastic material is provided between the annular spacer elements, which antiresonance ring is connected to the substrate discs on both sides.
Claim 3
Dependent Claim
30 words
An optical disc as claimed in Claim 1, characterized in that the antiresonance ring is provided outside the optical structure and near the spacer element located around the centre hole.
Claim 4
Dependent Claim
44 words
An optical disc as claimed in Claim 1 or 2, characterized in that the antiresonance ring comprises a synthetic resin annular element which is provided on both sides with an adhesive by means of which the antiresonance ring is connected to both substrate discs.
Claim 5
Dependent Claim
29 words
An optical disc as claimed in Claim 3, characterized in that the annular element is made of polyterephtalate and the adhesive is a glue on the basis of acrylate.
References Cited (Backward Citations)
EP0235812A1
Cited
EP0245953A1
Cited
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