US4886718A
Expired / Lapsed
US
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Device for reversible optical data storage
Assignee: Roehm GmbH Darmstadt
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Filing: 1987-02-03
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Granted: 1989-12-12
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Expires: 2007-02-03
Abstract
Abstract The invention relates to a device for reversible optical information storage, which comprises polymeric liquid crystals as a storage medium. The device contains a film comprised of a liquid crystal main chain polymer, as a storage medium, and is constructed so that in the storage operation the storage medium is locally reoriented, and the information is stored by means of a local variation of the molecular ordering.
Inventors
- 👤 Manfred Eich
- 👤 Joachim Wendorff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:32
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/004; G11B7/0065; C; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3804; C09K19/3809; C09K19/40; C09K19/406; C09K19/408; G11B11/00; G11B11/03; G11B11/10; G11B11/105; G11B11/10582; G11B7/242; G11B7/244; G11B7/245; G11B7/25
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
78 words
A device for reversible optical information storage, comprising: (i) a pair of transparent substrate plates; and (ii) a film in contact with said substrate plates and located therebetween, said film comprising a liquid crystal main chain polyester, polyesteramide or polysiloxane polymer in an oriented or disoriented state; and wherein the information is stored in said film by locally reorienting the said state of said film, whereby said reorienting produces a local variation of the ordering of said polymer.
Claim 2
Independent Claim
78 words
A device for reversible optical information storage, comprising: (i) a pair of transparent substrate plates; and (ii) a film in contact with said substrate plates and located therebetween, said film comprising a liquid crystal main chain polyester, polyesteramide or polysiloxane polymer in an oriented or disoriented state; and wherein the information is stored in said film by locally reorienting the said state of said film, whereby said reorienting produces a local variation of the ordering of said polymer.
Claim 3
Dependent Claim
11 words
The device of claim 1, wherein said film is macroscopically oriented.
Claim 4
Dependent Claim
11 words
The device of claim 1, wherein said film is macroscopically disoriented.
Claim 5
Dependent Claim
17 words
The device of claim 1, wherein said film is in the shape-stable state below the glass temperature.
Claim 6
Dependent Claim
17 words
The device of claim 1, wherein the film is in the viscoelastic state above the glass temperature.
Claim 7
Dependent Claim
20 words
The device of claim 1, wherein said polymer has a molecular weight in the range of about 1,000 to 20,000.
Claim 8
Dependent Claim
27 words
The device of claim 1, wherein said liquid crystal main chain polymer has a glass temperature in the range of about -40° C. to about 110° C.
Claim 9
Dependent Claim
22 words
The device of claim 1, wherein said polymer comprises the reaction product of a mesogenic diol with dicarboxylic acid or diisocyanate monomers.
Claim 10
Dependent Claim
67 words
The device of claim 1, wherein said polymer results from reacting (i) a bisphenol of formula ##STR27## where p is a number from 2 to 20 inclusive, (ii) a substituted hydroquinone of formula ##STR28## wherein R' is methyl, phenyl, chloro, or bromo; or (iii) a compound of formula ##STR29## with terephthalic acid or a diphenyldicarboxylic acid of formula ##STR30## wherein p' is a number from 2-20, inclusive.
Claim 11
Dependent Claim
12 words
The device of claim 9, wherein p and p' are 2-12 inclusive.
Claim 12
Dependent Claim
34 words
The device of claim 1, wherein said polymer results from the reaction of a dianiline of formula ##STR31## wherein p is a number from 2-20 inclusive, with terephthalic aldehyde, to form a Schiff base.
Claim 13
Dependent Claim
25 words
The device of claim 1, wherein said polyesteramide has the formula ##STR32## wherein X is methylene or oxygen and n' is 2 to 20, inclusive.
Claim 14
Dependent Claim
36 words
The device of claim 1, wherein said polysiloxane has the formula ##STR33## wherein M is a mesogenic group, and n" is a number from 2-°, inclusive and x is a number from 2 to 40 inclusive.
Claim 15
Dependent Claim
54 words
The device of claim 10, wherein said polymer contains monomer units having the formula ##STR34## wherein L represents --CH═--, --N═N--, ##STR35## --CH═CH--, --C.tbd.C--, --OC(O)--, --HC═C (CH 3 )--, --C(CH 3 )═N--N═C(CH 3 )--, phenyl or phenyl multiply and symmetrically substituted with methyl groups or halogen atoms; and m and m' are 0 to 1.
Claim 16
Independent Claim
89 words
A device for reversible optical information storage, comprising: (i) a pair of transparent substrate plates; and (ii) a film in contact with said substrate plates and located therebetween, said film comprising a liquid crystal main chain polymer and a dye, whereby the absorption properties of said film are adjusted, said film being in an oriented or disoriented state; and wherein the information is stored in said film by locally reorienting the said state of said film, whereby said reorienting produces a local variation of the ordering of said polymer.
Claim 17
Independent Claim
89 words
A device for reversible optical information storage, comprising: (i) a pair of transparent substrate plates; and (ii) a film in contact with said substrate plates and located therebetween, said film comprising a liquid crystal main chain polymer and a dye, whereby the absorption properties of said film are adjusted, said film being in an oriented or disoriented state; and wherein the information is stored in said film by locally reorienting the said state of said film, whereby said reorienting produces a local variation of the ordering of said polymer.
Claim 18
Dependent Claim
17 words
The device of claim 15, wherein said dye is incorporated into said polymer as a comonomer unit.
Claim 19
Dependent Claim
21 words
The device of claim 15, wherein the extinction level of said film is adjusted by changing the concentration of said dye.
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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) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |