US4076387A
Expired / Lapsed
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Magnetic display
Assignee: Xerox Corp
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Filing: 1976-07-02
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Granted: 1978-02-28
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Expires: 1996-07-02
Abstract
Abstract A magnetic display comprising, between two magnetic field permeable substrates, a ferrofluid and metal flakes, one of the substrates being provided with one or more selectively energizable electro-magnets.
Inventors
- 👤 Werner E. L. Haas
- 👤 Gary A. Dir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/091
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
47 words
A magneto-optic display comprising a layer of composition comprising a ferrofluid and metal flakes said layer of composition sandwiched between two magnetic field permeable substrates, one of said substrates being optically transparent and the other of said substrates having at least one selectively energizable electro-magnet affixed thereto.
Claim 2
Dependent Claim
47 words
A magneto-optic display comprising a layer of composition comprising a ferrofluid and metal flakes said layer of composition sandwiched between two magnetic field permeable substrates, one of said substrates being optically transparent and the other of said substrates having at least one selectively energizable electro-magnet affixed thereto.
Claim 3
Dependent Claim
20 words
The display of claim 1 wherein the other of said substrates has an array of selectively energizable electromagnets affixed thereto.
Claim 4
Dependent Claim
12 words
The display of claim 1 wherein said composition further includes a diluent.
Claim 5
Dependent Claim
34 words
The display of claim 3 wherein said composition comprises by weight from about 80% to about 98.5% diluent, from about 0.5% to about 8.5% ferrofluid, and from about 1% to about 16% metal flakes.
Claim 6
Dependent Claim
19 words
The display of claim 4 wherein said electromagnet can provide a magnetic field of at least about 0.5 gauss.
Claim 7
Dependent Claim
18 words
The display of claim 5 wherein said magnetic field is from about 0.5 gauss to about 300 gauss.
Claim 8
Dependent Claim
23 words
The display of claim 3 wherein said diluent comprises water and said ferrofluid comprises magnetic particles colloidally dispersed in an aqueous carrier liquid.
Claim 9
Dependent Claim
19 words
The display of claim 7 wherein said composition comprises by weight about 10% ferrofluid and about 10% metal flakes.
Claim 10
Dependent Claim
25 words
The display of claim 3 wherein said diluent comprises a hydrocarbon liquid and said ferrofluid comprises magnetic particles colloidally dispersed in a hydrocarbon carrier liquid.
Claim 11
Dependent Claim
26 words
The display of claim 9 wherein said composition comprises about one part ferrofluid, one part metal flakes and from about 10 to about 50 parts diluent.
Claim 12
Dependent Claim
26 words
The display of claim 9 wherein said composition comprises about one part ferrofluid, two parts metal flakes and from about 40 to about 200 parts diluent.
Claim 13
Dependent Claim
27 words
The display of claim 9 wherein said composition comprises about one part ferrofluid, about four parts metal flakes and from about 40 to about 200 parts diluent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |