Patent US4755012A successfully refreshed from Google Patents.
US4755012A
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US
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Ray absorption filter
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1986-05-30
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Granted: 1988-07-05
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Expires: 2006-05-30
Abstract
Abstract A near infrared ray absorption filter, particularly usable as a sharp cut filter for an infrared ray sensor, which comprises as an absorbent capable of controlling transmission of a ray at least one anthraquinone compound represented by the following formula, ##STR1## wherein A 1 , A 2 , A 3 and A 4 are different from each other or the same, and stand for a phenyl or naphthyl group unsubstituted or substituted with at least one alkyl, alkoxy, phenoxy or hydroxy group, and the rings A and B are unsubstituted or substituted with at least one lower alkyl group or halogen atom.
Inventors
- 👤 Kiyoteru Kojima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:16
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/223; C; C08; C08K; C08K5/00; C08K5/16; C08K5/17; C08K5/18; C09; C09D; C09D5/00; C09D5/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
80 words
A ray absorption filter comprising as an absorbent capable of controlling transmission of a ray at least one anthraquinone compound represented by the following formula, ##STR7## wherein A 1 , A 2 , A 3 and A 4 are independently stand for a phenyl or naphthyl group unsubstituted or substituted with at least one alkyl, alkoxy, phenoxy or hydroxyl group, and the rings A and B are unsubstituted or substituted with at least one lower alkyl group or halogen atom.
Claim 2
Dependent Claim
80 words
A ray absorption filter comprising as an absorbent capable of controlling transmission of a ray at least one anthraquinone compound represented by the following formula, ##STR7## wherein A 1 , A 2 , A 3 and A 4 are independently stand for a phenyl or naphthyl group unsubstituted or substituted with at least one alkyl, alkoxy, phenoxy or hydroxyl group, and the rings A and B are unsubstituted or substituted with at least one lower alkyl group or halogen atom.
Claim 3
Dependent Claim
40 words
A ray absorption filter according to claim 1, wherein the anthraquinone compound is the one having phenyl groups substituted with at least one alkyl or alkoxy group as A 1 , A 2 , A 3 and A 4 .
Claim 4
Dependent Claim
23 words
A ray absorption filter according to claim 1, wherein the anthraquinone compound is at least one member selected from 1,4,5,8-tetra(4'-methylphenylamino)anthraquinone, 1,4,5,8-tetra(4'-ethoxyphenylamino)anthraquinone, and 1,4,5,8-Tetra(4'-n-butylphenylamino)anthraquinone.
Claim 5
Dependent Claim
14 words
A ray absorption filter according to claim 1, wherein the anthraquinone compound is 1,4,5,8-tetra(4'-methylphenylamino)anthraquinone.
Claim 6
Dependent Claim
14 words
A ray absorption filter according to claim 1, wherein the anthraquinone compound is 1,4,5,8-tetra(4'-ethoxyphenylamino)anthraquinone.
Claim 7
Dependent Claim
42 words
A near infrared ray absorption filter according to claim 1, wherein the filter is a sharp cut filter for an infrared ray sensor showing a transmission limit of a short wavelength side in the wavelength region of from 800 to 900 nm.
References Cited (Backward Citations)
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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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |