US3756693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophoretic display device
Assignee: Panasonic Holdings Corp
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Filing: 1971-12-20
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Granted: 1973-09-04
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Expires: 1991-12-20
Abstract
Abstract An electrophoretic display device in which an electrophoretic suspension layer including a dispersion of at least one electrophoretic material in a finely divided powder form suspended in a suspending medium is interposed between a pair of electrodes, at least one of which is transparent. A colored layer of a desired pattern is provided at the transparent electrode. An electric field is imposed between the pair of electrodes so as to change the optical property such as reflective color or luminescent color of the suspension layer by changing the spatial distribution of the electrophoretic material in the suspending medium electrophoretically.
Inventors
- 👤 I Ota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/165; G02F1/166; G02F1/167; G02F1/1675; G02F1/1677; G03; G03G; G03G17/00; G03G17/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
138 words
An electrOphoretic display device comprising an electrophoretic suspension layer having a suspending medium and at least one electrophoretic material in a finely divided powder form suspended in said suspending medium, said suspension layer having two opposite major surfaces; a first electrode and a second electrode which are spaced from and opposed to each other and are positioned on said two opposite major surfaces of said suspension layer, respectively; at least one of said first electrode and said second electrode being transparent; a colored layer having at least one aperture in a desired pattern and positioned at the transparent electrode; and means coupled to said electrodes for applying an electric field across said suspension layer through said electrodes, said electric field changing the optical property of said suspension layer so as to produce a display of said desired pattern.
Claim 2
Dependent Claim
138 words
An electrOphoretic display device comprising an electrophoretic suspension layer having a suspending medium and at least one electrophoretic material in a finely divided powder form suspended in said suspending medium, said suspension layer having two opposite major surfaces; a first electrode and a second electrode which are spaced from and opposed to each other and are positioned on said two opposite major surfaces of said suspension layer, respectively; at least one of said first electrode and said second electrode being transparent; a colored layer having at least one aperture in a desired pattern and positioned at the transparent electrode; and means coupled to said electrodes for applying an electric field across said suspension layer through said electrodes, said electric field changing the optical property of said suspension layer so as to produce a display of said desired pattern.
Claim 3
Dependent Claim
22 words
A device as claimed in claim 1 wherein at least one of said electrodes is in the shape of the desired pattern.
Claim 4
Dependent Claim
19 words
A device as claimed in claim 1 wherein at least one of said electrodes has a plurality of segments.
Claim 5
Dependent Claim
53 words
A device as claimed in claim 1 wherein said first electrode consists of a plurality of strips of electrode material which are parallel to each other, and said second electrode consists of a plurality of strips of electrode material which are parallel to each other and are orthogonal to said first electrode strips.
Claim 6
Dependent Claim
19 words
A device as claimed in claim 1 wherein said colored layer has at least two color-different from each other.
Claim 7
Dependent Claim
13 words
A device as claimed in claim 1 wherein said colored layer is luminescent.
Claim 8
Dependent Claim
25 words
A device as claimed in claim 1 wherein said colored layer is against said transparent electrode and is between said electrode and said suspension layer.
Claim 9
Dependent Claim
15 words
A device as claimed in claim 1 further including a housing enclosing said suspension layer.
Claim 10
Dependent Claim
19 words
A device as claimed in claim 8 wherein said housing has a transparent housing wall covering said transparent electrode.
Claim 11
Dependent Claim
21 words
A device as claimed in claim 9 wherein said colored layer is between said transparent electrode and said transparent housing wall.
Claim 12
Dependent Claim
21 words
A device as claimed in claim 9 wherein said colored layer is on the outside surface of said transparent housing wall.
Claim 13
Dependent Claim
24 words
A device as claimed in claim 1 wherein the reflective color of said electrophoretic suspension layer is changeable by application of said electric field.
Claim 14
Dependent Claim
26 words
A device as claimed in claim 5 wherein said suspension layer is divided into a plurality of suspension units which differ in color from each other.
Claim 15
Dependent Claim
34 words
A device as claimed in claim 1 wherein said first electrode and second electrode are both transparent and further comprising an additional colored layer, there being a colored layer at both of said electrodes.
Claim 16
Dependent Claim
33 words
A device as claimed in claim 1 wherein one of the components of said suspension layer is luminescent, the luminescent color of said suspension layer being changeable by application of said electric field.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |