Patent US5450132A successfully refreshed from Google Patents.
Patent US4465338A successfully refreshed from Google Patents.
US4465338A
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Dyes for smectic cells
Assignee: STC PLC
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Filing: 1981-12-28
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Granted: 1984-08-14
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Expires: 2001-12-28
Abstract
Abstract A class of dyes is disclosed for use in smectic display cells which has the common feature of a strong absorption band registering with the emission line of a helium neon laser at 633 nm. The dyes have the general formula ##STR1## where X is an alkyl group or substituted alkyl group, and Y is an alkyl group, a phenyl group, or a substituted phenyl group.
Inventors
- 👤 David Coates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:08
CPC Classifications
C; C09; C09B; C09B1/00; C09B1/16; C09B1/20; C09B1/26; C09K; C09K19/00; C09K19/52; C09K19/60; C09K19/603
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A smectic display cell incorporating a smectic layer of material in which has been dissolved a dye having a strong optical absorption band registering with the helium neon laser emission line at 633 nm which dye satisfies the general formula ##STR3## where X is an alkyl group and Y is an alkyl group having at least 7 carbons, or a substituted phenyl group.
Claim 2
Dependent Claim
63 words
A smectic display cell incorporating a smectic layer of material in which has been dissolved a dye having a strong optical absorption band registering with the helium neon laser emission line at 633 nm which dye satisfies the general formula ##STR3## where X is an alkyl group and Y is an alkyl group having at least 7 carbons, or a substituted phenyl group.
Claim 3
Dependent Claim
15 words
A smectic display cell as claimed in claim 1 wherein X is a methyl group.
Claim 4
Dependent Claim
19 words
A smectic display cell as claimed in claim 1 or 2 wherein Y is an alkyl substituted phenyl group.
Claim 5
Dependent Claim
19 words
A smectic display cell as claimed in claim 1 or 2 wherein Y is an alkoxy substituted phenyl group.
Claim 6
Dependent Claim
19 words
A smectic display cell as claimed in claim 1 or 2 wherein Y is a dialkylamino substituted phenyl group.
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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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |