Patent US5961804A successfully refreshed from Google Patents.
US5961804A
Expired / Lapsed
US
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Microencapsulated electrophoretic display
Assignee: Massachusetts Institute of Technology
•
Filing: 1997-03-18
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Granted: 1999-10-05
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Expires: 2017-03-18
Abstract
Abstract An application-ready electrophoresis material includes a carrier and a dispersion of microcapsules therein, the microcapsules each containing a plurality of phases therein. At least some of the phases contrast visually and and exhibit differential responsiveness to an electric field, such that application of the field determines the visual appearance of the microcapsules. The material exhibits stability such the visual appearance persists despite removal of the field. In one aspect, the invention provides for enhanced stability of the visual appearance. In another aspect, the reflectivity of at least one of the phases is enhanced. In another aspect, one of the phases is particulate in nature and emits visible radiation.
Inventors
- 👤 Joseph Jacobson
- 👤 Barrett Comiskey
- 👤 Jonathan Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:32
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/165; G02F1/166; G02F1/167; G02F1/1675; G02F1/16757
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
51 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles at least some of the particles having an electrophoretic mobility; b. means for enhancing the reflectivity of at least some of the particles; and c. a dyed fluid.
Claim 2
Dependent Claim
51 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles at least some of the particles having an electrophoretic mobility; b. means for enhancing the reflectivity of at least some of the particles; and c. a dyed fluid.
Claim 3
Dependent Claim
31 words
The material of claim 1 wherein the means for enhancing reflectivity of at least some of the particles comprises a reflective material associated with the at least some of the particles.
Claim 4
Dependent Claim
17 words
The material of claim 2 wherein the reflective material is a metal shell coated over the particles.
Claim 5
Dependent Claim
13 words
The material of claim 3 wherein the reflective coating is a metal shell.
Claim 6
Dependent Claim
19 words
The material of claim 4 wherein the metal is selected from the group consisting of aluminum, silver and gold.
Claim 7
Dependent Claim
16 words
The material of claim 2 wherein the reflective material comprises metal flakes embedded within the particles.
Claim 8
Dependent Claim
20 words
The material of claim 2 wherein the reflective material is a quantity of glass retroreflector spheres embedded within the particles.
Claim 9
Dependent Claim
17 words
The material of claim 2 wherein the reflective material is an outer clear capsule surrounding each particle.
Claim 10
Dependent Claim
20 words
The material of claim 1 wherein the means for enhancing reflectivity comprises a reflective material dispersed in the liquid phase.
Claim 11
Dependent Claim
12 words
The material of claim 9 wherein the reflective material comprises clear particles.
Claim 12
Dependent Claim
28 words
The material of claim 10 wherein the liquid phase and the clear particles have refractive indices, the refractive index of the particles exceeding that of the liquid phase.
Claim 13
Dependent Claim
26 words
The material of claim 2 wherein at least some of the particles have a first optical property and the dyed fluid has a second optical property.
Claim 14
Dependent Claim
85 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles, at least some of the particles contrasting visually and being differentially responsive to an electric field such that, depending on the direction of the field, the at least some of the particles assume a first or a second visually differentiable appearance in accordance with a bistability characteristic and a threshold characteristic; and b. means for enhancing at least one of the characteristics.
Claim 15
Dependent Claim
85 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles, at least some of the particles contrasting visually and being differentially responsive to an electric field such that, depending on the direction of the field, the at least some of the particles assume a first or a second visually differentiable appearance in accordance with a bistability characteristic and a threshold characteristic; and b. means for enhancing at least one of the characteristics.
Claim 16
Dependent Claim
18 words
The material of claim 13 wherein the enhancing means comprising a liquid crystal material contained in the microcapsules.
Claim 17
Dependent Claim
60 words
The material of claim 13 wherein: a. the plurality of particles is dispersed in a carrier liquid; b. the particles each have a permanent charge; c. the microcapsules comprise interior surfaces; and d. the enhancing means comprises bound charges associated with the interior surfaces of the microcapsules, the bound charges being opposite in sign to the charges of the particles.
Claim 18
Dependent Claim
20 words
The material of claim 15 wherein the bound charges comprise at least one charge-control additive associated with the interior surfaces.
Claim 19
Dependent Claim
43 words
The material of claim 13 wherein the plurality of particles comprises a first quantity of particles having a first optical property and a second quantity of particles having a second optical property, the first and second quantity of particles exhibiting different triboelectric properties.
Claim 20
Dependent Claim
28 words
The material of claim 13 wherein the microcapsules have interior surfaces, the at least some of the plurality of particles and the interior surfaces exhibiting different triboelectric properties.
Claim 21
Dependent Claim
34 words
The material of claim 13 wherein the particles comprise at least one charging agent selected from the group consisting of of (a) adsorbed charging agents, (b) copolymerized charging agents, and (c) embedded charging agents.
Claim 22
Dependent Claim
12 words
The material of claim 19 wherein the charging agent is an emitter.
Claim 23
Dependent Claim
23 words
The material of claim 13 wherein the at least some of the plurality of particles comprise particles of a semiconductor or varistor material.
Claim 24
Dependent Claim
15 words
The material of claim 13 further comprising a liquid having a charge-control agent dissolved therein.
Claim 25
Dependent Claim
10 words
A printed electronic display comprising the material of claim 1.
Claim 26
Dependent Claim
10 words
A printed electronic display comprising the material of claim 13.
Claim 27
Dependent Claim
61 words
The material of claim 13 wherein the microcapsules further comprise a carrier liquid that is substantially transparent, a first quantity of the particles having a first optical property and a first charge and a second quantity of the particles having a second optical property and a second charge different from the first charge, the first and second optical properties differing visually.
Claim 28
Dependent Claim
88 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a dyed fluid; b. a plurality of particles, at least some of the particles contrasting visually and being differentially responsive to an electric field such that, depending on the direction of the field, at least some of the particles assume a first or a second visually differentiable appearance in accordance with a bistability characteristic and a threshold characteristic; and c. means for enhancing at least one of the characteristics.
Claim 29
Dependent Claim
88 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a dyed fluid; b. a plurality of particles, at least some of the particles contrasting visually and being differentially responsive to an electric field such that, depending on the direction of the field, at least some of the particles assume a first or a second visually differentiable appearance in accordance with a bistability characteristic and a threshold characteristic; and c. means for enhancing at least one of the characteristics.
Claim 30
Dependent Claim
18 words
The material of claim 26 wherein the enhancing means comprises a liquid crystal material contained in the microcapsules.
Claim 31
Dependent Claim
60 words
The material of claim 26 wherein: a. the plurality of particles is dispersed in a carrier liquid; b. the particles each have a permanent charge; c. the microcapsules comprise interior surfaces; and d. the enhancing means comprises bound charges associated with the interior surfaces of the microcapsules, the bound charges being opposite in sign to the charges of the particles.
Claim 32
Dependent Claim
20 words
The material of claim 28 wherein the bound charges comprise at least one charge-control additive associated with the interior surfaces.
Claim 33
Dependent Claim
43 words
The material of claim 26 wherein the plurality of particles comprises a first quantity of particles having a first optical property and a second quantity of particles having a second optical property, the first and second quantity of particles exhibiting different triboelectric properties.
Claim 34
Dependent Claim
28 words
The material of claim 26 wherein the microcapsules have interior surfaces, the at least some of the plurality of particles and the interior surfaces exhibiting different triboelectric properties.
Claim 35
Dependent Claim
33 words
The material of claim 26 wherein the particles comprise at least one charging agent selected form the group consisting of (a) adsorbed charging agents, (b) copolymerized charging agents, and (c) embedded charging agents.
Claim 36
Dependent Claim
12 words
The material of claim 32 wherein the charging agent is an emitter.
Claim 37
Dependent Claim
22 words
The material of claim 26 wherein at least some of the plurality of particles comprise particles of a semiconductor or varistor material.
Claim 38
Dependent Claim
15 words
The material of claim 26 further comprising a liquid having a charge-control agent dissolved therein.
Claim 39
Dependent Claim
60 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles, at least some of the particles having a first electrophoretic mobility and at least some of the particles having a second electrophoretic mobility; and b. means for enhancing the reflectivity of at least some of the particles.
Claim 40
Dependent Claim
60 words
An electrophoretic or dielectrophoretic material comprising a carrier and a dispersion of microcapsules therein, the microcapsules each comprising: a. a plurality of particles, at least some of the particles having a first electrophoretic mobility and at least some of the particles having a second electrophoretic mobility; and b. means for enhancing the reflectivity of at least some of the particles.
Claim 41
Dependent Claim
31 words
The material of claim 36 wherein the means for enhancing reflectivity of at least some of the particles comprises a reflective material associated with the at least some of the particles.
Claim 42
Dependent Claim
17 words
The material of claim 37 wherein the reflective material is a metal shell coated over the particles.
Claim 43
Dependent Claim
19 words
The material of claim 38 wherein the metal is selected from the group consisting of aluminum, silver and gold.
Claim 44
Dependent Claim
16 words
The material of claim 37 wherein the reflective material comprises metal flakes embedded within the particles.
Claim 45
Dependent Claim
20 words
The material of claim 37 wherein the reflective material is a quantity of glass retroreflector spheres embedded within the particles.
Claim 46
Dependent Claim
17 words
The material of claim 37 wherein the reflective material is an outer clear capsule surrounding each particle.
Claim 47
Dependent Claim
20 words
The material of claim 36 wherein the means for enhancing reflectivity comprises a reflective material dispersed in the liquid phase.
Claim 48
Dependent Claim
12 words
The material of claim 43 wherein the reflective material comprises clear particles.
Claim 49
Dependent Claim
30 words
The material of claim 44 wherein the liquid phase and the clear particles have refractive indices, the refractive index of the particles exceeding the refractive index of the liquid phase.
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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) | 2002-10-04 | 2003-04-05 | 2003-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-04 | 2007-04-05 | 2007-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-04 | 2011-04-05 | 2011-10-05 | $7700.00 | Window Closed / Lapsed |