Patent US4294367A successfully refreshed from Google Patents.
US4837745A
Expired / Lapsed
US
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Process for the reversible optical storage of data
Assignee: Roehm GmbH Darmstadt
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Filing: 1987-02-03
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Granted: 1989-06-06
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Expires: 2007-02-03
Abstract
Abstract The invention concerns a process for reversible optical information storage by means of a liquid crystal storage medium, whereby the information is stored in a firm of a liquid crystal side chain polymer in an anisotropic phase by means of locally acting heat source in combination with an electric, magnetic or surfaces active field, through local reorientation.
Inventors
- 👤 Manfred Eich
- 👤 Joachim Wendorff
- 👤 Bernd Reck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:24
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/132; G02F1/137; G02F1/13768; G11B; G11B13/00; G11B7/00; G11B7/004; G11B7/0055; G11B7/00555; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/245; G11B7/25
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
83 words
A process for reversible optical information storage which utilizes a device comprising (1) a substrate, and (2) a film comprising a liquid crystal side chain polymer in contact with said substrate, comprising the steps of: (a) storing information below the glass temperature of said liquid crystal side chain polymer and within the stable shape retention state of said polymer on said device by locally reorienting said film; and (b) reading stored information from said device by illuminating said film with coherent monochromatic light.
Claim 2
Dependent Claim
83 words
A process for reversible optical information storage which utilizes a device comprising (1) a substrate, and (2) a film comprising a liquid crystal side chain polymer in contact with said substrate, comprising the steps of: (a) storing information below the glass temperature of said liquid crystal side chain polymer and within the stable shape retention state of said polymer on said device by locally reorienting said film; and (b) reading stored information from said device by illuminating said film with coherent monochromatic light.
Claim 3
Dependent Claim
11 words
The process of claim 1, wherein said film is macroscopically oriented.
Claim 4
Dependent Claim
11 words
The process of claim 1, wherein said film is macroscopically disoriented.
Claim 5
Dependent Claim
36 words
The process of claim 1, further comprising: erasing stored information by locally heating said film; and cooling said film in an electric, magnetic or surface active field, whereby the original state of orientation is locally restored.
Claim 6
Dependent Claim
42 words
The process of claim 1, further comprising: erasing the entirety of stored information by heating all of said film; and cooling said film in an electric, magnetic or surface active field, whereby the state of orientation is restored to the entire film.
Claim 7
Dependent Claim
31 words
The process of claim 1, further comprising: erasing the entirety of stored information from said film by heating said film to a temperature above the nematic-isotropic temperature; and cooling said film.
Claim 8
Dependent Claim
20 words
The process of claims 6 or 7, wherein said heating produces an anisotropic, liquid phase of said liquid crystal polymer.
Claim 9
Dependent Claim
19 words
The process of claims 6 or 7, wherein said heating produces an isotropic phase of said liquid crystal polymer.
Claim 10
Dependent Claim
25 words
The process of claim 1, wherein said liquid crystal polymer has a molecular weight Mn within a range of 10 3 to 10 5 .
Claim 11
Dependent Claim
15 words
The process of claim 1, wherein said reorienting is performed by heating with a laser.
Claim 12
Dependent Claim
37 words
The process of claim 10, wherein said storing is performed by a laser of suitable wavelength and intensity and said reading is performed by a different laser having a different wavelength, without interfering with the stored information.
Claim 13
Dependent Claim
41 words
The process of claim 1, wherein said liquid crystal side chain polymer comprises repeating units having the formula ##STR36## wherein A--B is an element of the main chain polymer, X is a spacer unit and Y is a mesogenic side group.
Claim 14
Dependent Claim
15 words
The process of claim 12, wherein said mesogenic side group is of the smectogenic type.
Claim 15
Dependent Claim
14 words
The process of claim 12, wherein said repeating units are acrylate or methacrylate units.
Claim 16
Dependent Claim
12 words
The process of claim 12, wherein said repeating units are polyester units.
Claim 17
Dependent Claim
20 words
The process of claim 1, wherein said film is disposed between two plates or films arranged one above the other.
Claim 18
Dependent Claim
22 words
The process of claim 10, further comprising: adjusting the absorption range of said film to correspond to the wavelength of said laser.
Claim 19
Dependent Claim
13 words
The process of claim 17, wherein said adjusting is performed by a dye.
Claim 20
Dependent Claim
26 words
The process of claim 17, wherein said adjusting is performed by copolymerizing a dye-containing comonomer with the repeating monomers of said liquid crystal side chain polymer.
Claim 21
Dependent Claim
15 words
The process of claim 18, wherein said adjusting is performed by varying the dye concentration.
Claim 22
Dependent Claim
23 words
The process of claim 1, wherein said reading step is performed with light having a wavelength outside the absorption maximum of said film.
Claim 23
Dependent Claim
22 words
The process of claim 1, wherein said storing step is performed by holographically illuminating said film, whereby an interference pattern is stored.
Claim 24
Dependent Claim
29 words
The process of claim 22, wherein said storing step is performed in an optical analog manner and said reading is performed by illuminating said film with coherent monochromatic light.
Claim 25
Dependent Claim
13 words
The process of claim 10, wherein said storing step stores digital phase structure.
Claim 26
Dependent Claim
23 words
The process of claim 24, wherein said laser and said film are moved relative to each other during said storing and reading steps.
Claim 27
Dependent Claim
16 words
The process of claim 24, or 25, wherein said laser is modulated during said storing step.
Claim 28
Dependent Claim
36 words
The process of claim 26, wherein a digital phase structure is stored in said film by means of a predetermined intensity modulation and said reading is performed by illuminating said film with a reference light source.
Claim 29
Dependent Claim
13 words
The process of claim 27, wherein said intensity modulation si determined by computation.
Claim 30
Dependent Claim
21 words
The process of claim 22, wherein the information density produced from said storing step is at most 2000 lines per mm.
Claim 31
Dependent Claim
29 words
The process of claim 1, wherein said information is optical signal process information, Fourier transformation and Fourier convolution information, image processing information, coherent optical correlation information or holographic information.
Claim 32
Dependent Claim
17 words
The process of claim 1, wherein said reorienting is performed by the application of an electrical field.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |