Patent US4747674A successfully refreshed from Google Patents.
US4747674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contrast enhancement filter
Assignee: 3M Innovative Properties Co
•
Filing: 1987-03-30
•
Granted: 1988-05-31
•
Expires: 2007-03-30
Abstract
Abstract A contrast enhancement filter having antistatic and antireflection properties is disclosed. The article comprises a plastic support sheet carrying on one side thereof a layer of indium tin oxide, and superposed upon said layer, an antireflection layer. A light-polarizing element is affixed to the opposed side thereof. The contrast enhancement filter can be used for the reduction of specular glare from the surface of cathode ray tubes, computer display screens and the like.
Inventors
- 👤 William F. Butterfield
- 👤 Kuang-Chou Chang
- 👤 Edmund J. McLelland
- 👤 Leonard Polizzotto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:45
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3033; H; H01; H01J; H01J29/00; H01J29/86; H01J29/89; H01J29/896; H05; H05F; H05F3/00; H01J2229/00; H01J2229/89; H01J2229/8913; H01J2229/8918
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
53 words
A contrast enhancement filter having antistatic and antireflection properties, said filter comprising a transparent plastic sheet carrying on one side thereof, a layer of indium tin oxide, and superposed upon said indium tin oxide layer, an antireflection layer, said filter having affixed to the opposed side of said plastic sheet, a light-polarizing element.
Claim 2
Dependent Claim
53 words
A contrast enhancement filter having antistatic and antireflection properties, said filter comprising a transparent plastic sheet carrying on one side thereof, a layer of indium tin oxide, and superposed upon said indium tin oxide layer, an antireflection layer, said filter having affixed to the opposed side of said plastic sheet, a light-polarizing element.
Claim 3
Dependent Claim
17 words
The contrast enhancement filter of claim 1 wherein said layer of indium tin-oxide is a sputtered layer.
Claim 4
Dependent Claim
25 words
The contrast enhancement filter of claim 1 wherein said sputtered layer has a thickness in the range of about 130 Angstroms to about 180 Angstroms.
Claim 5
Dependent Claim
20 words
The contrast enhancement filter of claim 3 wherein said thickness is in the range of 140 Angstroms to 160 Angstroms.
Claim 6
Dependent Claim
15 words
The contrast enhancement filter of claim 1 wherein said antireflection layer comprises an inorganic layer.
Claim 7
Dependent Claim
14 words
The contrast enhancement filter of claim 5 wherein said inorganic layer comprises magnesium fluoride.
Claim 8
Dependent Claim
24 words
The contrast enhancement filter of claim 6 wherein said layer of magnesium fluoride has a thickness of about 1050 Angstroms to about 1400 Angstroms.
Claim 9
Dependent Claim
23 words
The contrast enhancement filter of claim 7 wherein said magnesium fluoride layer has a thickness of about 1100 Angstroms to about 1300 Angstroms.
Claim 10
Dependent Claim
15 words
The contrast enhancement filter of claim 1 wherein said antireflection layer comprises a polymeric layer.
Claim 11
Dependent Claim
16 words
The contrast enhancement filter of claim 9 wherein said polymeric layer comprises a fluorinated polymer layer.
Claim 12
Dependent Claim
25 words
The contrast enhancement filter of claim 10 wherein said fluorinated polymer has an index of refraction in the range of about 1.3 to about 1.45.
Claim 13
Dependent Claim
28 words
The contrast enhancement filter of claim 11 wherein said fluorinated polymer layer includes therein or as a layer contiguous thereto an effective amount of an isocyanate adhesion-promoting agent.
Claim 14
Dependent Claim
18 words
The contrast enhancement filter of claim 11 wherein said fluorinated polymer layer includes therein a dimethyl siloxane polymer.
Claim 15
Dependent Claim
21 words
The contrast enhancement filter of claim 10 wherein said fluorinated polymer layer has a thickness of about 1050 to 1400 Angstroms.
Claim 16
Dependent Claim
17 words
The contrast enhancement filter of claim 1 wherein said transparent plastic sheet comprises a flexible polyester sheet.
Claim 17
Dependent Claim
15 words
The contrast enhancement filter of claim 15 wherein said flexible polyester sheet comprises polyethylene terephthalate.
Claim 18
Dependent Claim
24 words
The contrast enhancement filter of claim 16 wherein the side of said sheet carrying said layer of indium tin oxide is corona discharge treated.
Claim 19
Dependent Claim
33 words
The control enhancement filter of claim 1 wherein said light-polarizing element is a circular light polarizer comprising, in combination, a linear light-polarizing layer and a quarter-wave retardation plate on a plastic sheet material.
Claim 20
Dependent Claim
19 words
The contrast enhancement filter of claim 18 wherein said light-polarizing layer comprises a polyvinyl alcohol linear dichroic light-polarizing layer.
Claim 21
Dependent Claim
20 words
The contrast enhancement filter of claim 18 wherein said plastic sheet material carrying said quarter-wave retardation plate comprises cellulose triacetate.
References Cited (Backward Citations)
US3518373A
Cited
US3576356A
Cited
US4389452A
Cited
US3962488A
Cited
GB2012943A
Cited
US4168986A
Cited
US4278736A
Cited
US4526818A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |