US4126528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophoretic composition and display device
Assignee: Xerox Corp
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Filing: 1977-07-26
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Granted: 1978-11-21
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Expires: 1997-07-26
Abstract
Abstract Electrophoretic display device containing a suspension of hollow particles in an insulating medium, wherein the weight density of the particles is equal to, or within five percent of, that of the insulating medium. Settling out of the particles is, thus, greatly reduced or eliminated during periods of non-use.
Inventors
- 👤 Anne Chiang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/165; G02F1/166; G02F1/167; C; C25; C25D; C25D13/00; C25D13/22; G03; G03G; G03G17/00; G03G17/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
55 words
An electrophoretic display composition, comprising, electrophoretically-active hollow-core particles in a liquid or liquefiable suspension medium, wherein the weight density of the particles is equal to, or within five percent of, that of the suspension medium as a liquid, and wherein the surface refractive index of the particles is greater than that of the suspension medium.
Claim 2
Dependent Claim
55 words
An electrophoretic display composition, comprising, electrophoretically-active hollow-core particles in a liquid or liquefiable suspension medium, wherein the weight density of the particles is equal to, or within five percent of, that of the suspension medium as a liquid, and wherein the surface refractive index of the particles is greater than that of the suspension medium.
Claim 3
Dependent Claim
20 words
The composition of claim 1 where the hollow-core particles comprise a shell having an outer coating of an electrophoretically-active material.
Claim 4
Dependent Claim
16 words
The composition of claim 1 wherein the hollow-core particles consist of a shell of electrophoretically-active material.
Claim 5
Dependent Claim
12 words
The composition of claim 2 wherein said electrophoretically-active material is a pigment.
Claim 6
Dependent Claim
12 words
The composition of claim 3 wherein said electrophoretically-active material is a pigment.
Claim 7
Dependent Claim
29 words
An electrophoretic display device comprising, a housing, two spaced facing electrodes therein, at least one of which is transparent, the space therebetween containing the electrophoretic composition of claim 1.
Claim 8
Dependent Claim
26 words
A method of electrophoretically migrating the particles of an electrophoretic suspension, comprising, applying an electric potential to the electrodes of the display device of claim 6.
Claim 9
Dependent Claim
98 words
A method of preparing the composition of claim 1, comprising: (a) providing a first flotation liquid having a weight density five percent or less above that of the suspending medium as a liquid; (b) providing a second flotation liquid having a weight density five percent or less below that of said suspending medium as a liquid; (c) mixing hollow-core electrophoretically-active particles in said flotation liquids; (d) collecting those particles which both float to the surface of said first flotation liquid and which sink in said second flotation liquid; and (e) dispersing said collected particles in the suspending medium.
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) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |