US3816237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optically inactive magneto-optic substrate
Assignee: International Business Machines Corp
•
Filing: 1973-02-26
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Granted: 1974-06-11
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Expires: 1993-02-26
Abstract
Abstract The use of poly(parabanic acids) as a substrate for magnetooptic data storage applications. For example, the substrate is characterized by having optical inactivity and may be made free of stress induced dichroism and birefringence, thus being particularly suitable for use with magneto-optic storage films where information stored is read by utilizing the Kerr or Faraday effects.
Inventors
- 👤 E Barrall
- 👤 K Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:23
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/26; H01F10/28; G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
16 words
The method of claim 1 wherein the substrate is in the form of a rigid medium.
Claim 2
Dependent Claim
15 words
The data storage medium of claim 1 wherein the substrate is in a non-rigid form.
Claim 3
Dependent Claim
16 words
The data storage medium of claim 1 wherein the substrate is in the form of tape.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein a substrate is in disk form.
Claim 5
Dependent Claim
66 words
In a data storage medium wherein information is stored in a storage layer upon a polymer substrate by the application of heat to a temperature of up to substantially 460* C to a localized area of the layer to affect at least one physical property of the area, the improvement for the purpose of higher temperature stability comprising using as the substrate substantially unstressed poly(parabanic acid).
Claim 6
Dependent Claim
16 words
The method of claim 6 wherein the substrate is in the form of a rigid medium.
Claim 7
Dependent Claim
15 words
The data storage medium of claim 6 wherein the substrate is in a non-rigid form.
Claim 8
Dependent Claim
16 words
The data storage medium of claim 6 wherein the substrate is in the form of tape.
Claim 9
Dependent Claim
12 words
The method of claim 6 wherein a substrate is in disk form.
Claim 10
Dependent Claim
70 words
In the method of making a data storage medium by the method of depositing a storage layer upon a substrate maintained at a temperature of up to substantially 460* C during deposition or during subsequent heat treatment, the improvement for the purpose of higher temperature stability while maintaining optical inactivity to achieve a substrate free of stress induced dichroism and birefringence comprising using as the substrate substantially amorphous polyparabanci acid.
Claim 11
Dependent Claim
16 words
The method of claim 11 wherein the substrate is in the form of a rigid medium.
Claim 12
Dependent Claim
15 words
The data storage medium of claim 11 wherein the substrate is in a non-rigid form.
Claim 13
Dependent Claim
16 words
The data storage medium of claim 11 wherein the substrate is in the form of tape.
Claim 14
Dependent Claim
12 words
The method of claim 11 wherein a substrate is in disk form.
References Cited (Backward Citations)
US3521257A
Cited
US3626394A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |