Patent US5333075A successfully refreshed from Google Patents.
US5333075A
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Ferroelectric liquid crystal mixtures containing lipohilizing, lipophilic or amphiphilic compounds for eliminating ionic impurities
Assignee: Hoechst AG
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Filing: 1993-04-15
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Granted: 1994-07-26
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Expires: 2013-04-15
Abstract
Abstract Electro-optical display devices having a cell thickness of 1 to 10 mu m, and containing ferroelectric liquid crystalline mixture, electrodes, alignment layer(s), in which the ferroelectric liquid crystalline mixture has a spontaneous polarization of Ps>20nC.cm-2 and a natural helical pitch of less than a half of the cell thickness, and contains lipophilizing, lipophilic or amphiphilic compounds for eliminating ionic impurities, Ferroelectric liquid crystal compositions according to the invention show a significantly reduced surface memory effect and an improved display contrast.
Inventors
- 👤 Takamasa Harada
- 👤 Claus Escher
- 👤 Gerd Illian
- 👤 Anke Kaltbeitzel
- 👤 Norbert Rosch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; G02F1/1416; C; C09; C09K; C09K19/00; C09K19/02; C09K19/0225; C09K19/52; C09K19/58; C09K19/582; C09K19/584; C09K19/586; C09K19/588
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
35 words
Ferroelectric liquid crystal mixtures having a spontaneous polarization of Ps>20nC.cm -2 and a natural helical pitch of less than one half of the cell thickness, and comprising at least one lipophilizing, lipophilic and/or amphiphilic compound.
Claim 2
Dependent Claim
35 words
Ferroelectric liquid crystal mixtures having a spontaneous polarization of Ps>20nC.cm -2 and a natural helical pitch of less than one half of the cell thickness, and comprising at least one lipophilizing, lipophilic and/or amphiphilic compound.
Claim 3
Dependent Claim
12 words
Display devices comprising ferroelectric liquid crystal mixtures as claimed in claim 1.
Claim 4
Dependent Claim
61 words
Electro-optical display devices having a FLC layer thickness of 1 to 10 μm pro, comprising ferroelectric liquid crystal mixtures, electrodes and alignment layer(s), in which said ferroelectric liquid crystal mixtures have a spontaneous polarization of Ps>20nC.cm -2 and a natural helical pitch of less than one half of the cell thickness, and comprise at least one lipophilizing, lipophilic and/or amphiphilic compound.
Claim 5
Dependent Claim
61 words
Electro-optical display devices having a FLC layer thickness of 1 to 10 μm pro, comprising ferroelectric liquid crystal mixtures, electrodes and alignment layer(s), in which said ferroelectric liquid crystal mixtures have a spontaneous polarization of Ps>20nC.cm -2 and a natural helical pitch of less than one half of the cell thickness, and comprise at least one lipophilizing, lipophilic and/or amphiphilic compound.
Claim 6
Dependent Claim
28 words
Display devices as claimed in claim 3, in which the structure of smectic layer of said ferroelectric liquid crystal mixture is a bookshelf geometry or a quasi-bookshelf geometry.
Claim 7
Dependent Claim
22 words
Display devices as claimed in claim 4, in which said bookshelf geometry or quasi-bookshelf geometry is formed by an electric field treatment.
Claim 8
Dependent Claim
23 words
Display devices as claimed in claim 4, in which said bookshelf geometry or quasi-bookshelf geometry has a tilt angle of less than 10°.
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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) | 1997-07-25 | 1998-01-24 | 1998-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-25 | 2002-01-24 | 2002-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-25 | 2006-01-24 | 2006-07-26 | $7700.00 | Window Closed / Lapsed |