US4702945A
Expired / Lapsed
US
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Optical recording medium
Assignee: BASF SE
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Filing: 1985-08-09
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Granted: 1987-10-27
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Expires: 2005-08-09
Abstract
Abstract An optical recording medium contains, on a base, one or more dyes and a polymer which forms liquid-crystalline phases. The information is written into the uniformly oriented liquid-crystalline polymer layer, for example by means of a laser. During this procedure, the polymer heats up locally to above a phase transition temperature. By cooling, the resulting change is frozen in the glass state. The information can be erased by applying an electric field and/or heating. The recording material permits high-contrast storage and possesses high sensitivity, good resolution and excellent stability.
Inventors
- 👤 Karl-Heinz Etzbach
- 👤 Peter Neumann
- 👤 Matthias Dust
- 👤 Helmut Ringsdorf
- 👤 Hans-Werner Schmidt
- 👤 Guenter Baur
- 👤 Friedrich Windscheid
- 👤 Rudolf Kiefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:19
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/25; C; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3833; C09K19/3842; C09K19/3852; C09K19/3861; C09K19/40; C09K19/406; C09K19/408; G11B7/245; G11B7/246; G11B7/248
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
40 words
An optical recording medium which possesses, on a base or between two supports, a layer comprising a polymer which forms liquid-crystalline phases and contains one or more dyes wherein the dye is chemically bonded, via a spacer, to the polymer.
Claim 2
Dependent Claim
40 words
An optical recording medium which possesses, on a base or between two supports, a layer comprising a polymer which forms liquid-crystalline phases and contains one or more dyes wherein the dye is chemically bonded, via a spacer, to the polymer.
Claim 3
Dependent Claim
16 words
An optical recording medium as claimed in claim 1, wherein the polymer contains a pleochroic dye.
Claim 4
Dependent Claim
19 words
An optical recording medium as claimed in claim 1, wherein the polymer forming liquid-crystalline phases forms a nematic phase.
Claim 5
Dependent Claim
23 words
An optical recording medium as claimed in claim 1, wherein the polymer forming liquid-crystalline phases forms a nematic phase and a smectic phase.
Claim 6
Dependent Claim
19 words
An optical recording medium as claimed in claim 1, wherein the polymer forming liquid-crystalline phases forms a cholesteric phase.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |