US5013593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information storage medium and process for producing the same
Assignee: Fujifilm Holdings Corp
•
Filing: 1989-10-05
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Granted: 1991-05-07
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Expires: 2009-10-05
Abstract
Abstract Disclosed is an information storage medium having an air-sandwich structure which comprises two disc-shaped substrates joined together through a ring-shaped inner spacer and a ring-shaped outer spacer. These spacers are made of the same kind of resin as those forming the disc substrates and the resin of the spacers has a viscosity-average molecular weight larger than that of the resin of the substrates. Also disclosed is a process for producing the information storage medium by joining the spacers to the disc substrates by means of ultrasonic welding.
Inventors
- 👤 Hideki Matsuzawa
- 👤 Masao Yabe
- 👤 Tadashi Irie
- 👤 Seiichi Watanabe
- 👤 Yusuke Ishihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:59
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/24015; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T156/00; Y10T156/10; Y10T428/00; Y10T428/31504; Y10T428/31507
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
An information storage medium of air-sandwich structure comprising two disc-shaped substrates joined together through a ring-shaped outer spacer and a ring-shaped inner spacer, wherein each of the spacers is made of the same kind of resin as that forming the disc-shaped substrates and the resin of the spacers has a viscosity-average molecular weight in the range of 1.3 to 2.0 times the viscosity-average molecular weight of the resin of the disc-shaped substrates.
Claim 2
Dependent Claim
72 words
An information storage medium of air-sandwich structure comprising two disc-shaped substrates joined together through a ring-shaped outer spacer and a ring-shaped inner spacer, wherein each of the spacers is made of the same kind of resin as that forming the disc-shaped substrates and the resin of the spacers has a viscosity-average molecular weight in the range of 1.3 to 2.0 times the viscosity-average molecular weight of the resin of the disc-shaped substrates.
Claim 3
Dependent Claim
48 words
The information storage medium as claimed in claim 1, wherein the viscosity-average molecular weight of the resin of the spacers is in the range of 13,000 to 30,000, and the viscosity-average molecular weight of the resin of the disc-shaped substrates is in the range of 10,000 to 20,000.
Claim 4
Dependent Claim
21 words
The information storage medium as claimed in claim 1, wherein the resin for the spacers and the disc-shaped substrates is polycarbonate.
Claim 5
Dependent Claim
24 words
The information storage medium as claimed in claim 1, wherein each of the spacers is provided with an energy director on both sides thereof.
Claim 6
Dependent Claim
81 words
A process for an information storage medium of air-sandwich structure comprising two disc-shaped substrates joined together through a ring-shaped outer spacer and a ring-shaped inner spacer, wherein the spacers are made of the same kind of resin as that forming the substrates, said resin of the spacers having a viscosity-average molecular weight in the range of 1.3 to 2.0 times the viscosity-average molecular weight of the resin of the disc-shaped substrates, are joined to the substrates by means of ultrasonic welding.
Claim 7
Dependent Claim
81 words
A process for an information storage medium of air-sandwich structure comprising two disc-shaped substrates joined together through a ring-shaped outer spacer and a ring-shaped inner spacer, wherein the spacers are made of the same kind of resin as that forming the substrates, said resin of the spacers having a viscosity-average molecular weight in the range of 1.3 to 2.0 times the viscosity-average molecular weight of the resin of the disc-shaped substrates, are joined to the substrates by means of ultrasonic welding.
Claim 8
Dependent Claim
46 words
The process as claimed in claim 1, wherein the viscosity-average molecular weight of the resin of the spacers is in the range of 13,000 to 30,000, and the viscosity-average molecular weight of the resin of the disc-shaped substrates is in the range of 10,000 to 20,000.
Claim 9
Dependent Claim
19 words
The process as claimed in claim 1, wherein the resin of the spacers and the disc-shaped substrates is polycarbonate.
Claim 10
Dependent Claim
22 words
The process as claimed in claim 1, wherein each of the spacers is provided with an energy director on both sides thereof.
References Cited (Backward Citations)
JPS62173656A
Cited
US4847827A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |