Patent US4229075A successfully refreshed from Google Patents.
US4229075A
Expired / Lapsed
US
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Electrostatic display device
Assignee: DISPLAYTEK CORP
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Filing: 1978-08-07
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Granted: 1980-10-21
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Expires: 1998-08-07
Abstract
Abstract An electrostatic display device includes an insulative base, a substantially transparent fixed electrode mounted on the base, a substantially transparent dielectric layer such as silicon dioxide applied on the outer surface of the fixed electrode, a resilient sheet electrode fixed at one end thereof to the base and extending therefrom adjacent to the fixed electrode, a means for applying a voltage between the fixed electrode and the sheet electrode, and a display placed on or behind the inner surface of the fixed electrode. When there is no voltage between the fixed and the sheet electrodes, the display is visible through the transparent fixed electrode and the dielectric layer, whereas upon applying a voltage between the fixed and the sheet electrodes, the sheet electrode is attracted to and covers the outer surface of the fixed electrode, thereby concealing the display. The fixed electrode preferably comprises a transparent glass mold having a layer of an electrically conductive material such as stannic oxide chemically vapor-deposited on the outer surface thereof.
Inventors
- 👤 Hirotada Ueda
- 👤 Satoshi Ihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:11
CPC Classifications
G; G09; G09F; G09F9/00; G09F9/30; G09F9/37; G09F9/372
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
164 words
An electrostatic display device comprising: an insulative base; a substantially transparent fixed electrode mounted on the base, said fixed electrode being constructed of an electrically conductive transparent material, said fixed electrode having inner and outer surfaces; a substantially transparent dielectric layer applied on said outer surface of said fixed electrode; at least one resilient sheet electrode fixed at one end thereof to the base and extending therefrom adjacent to the fixed electrode; a means for applying a voltage between the fixed electrode and the resilient sheet electrode; and a display placed on or behind said inner surface of the fixed electrode; whereby when there is no voltage between the fixed electrode and the sheet electrode, the display is visible through the substantially transparent fixed electrode and the substantially transparent dielectric layer thereon, whereas upon applying a voltage between the fixed electrode and the sheet electrode, the sheet electrode is attracted to and covers the outer surface of the fixed electrode, thereby concealing the display.
Claim 2
Dependent Claim
164 words
An electrostatic display device comprising: an insulative base; a substantially transparent fixed electrode mounted on the base, said fixed electrode being constructed of an electrically conductive transparent material, said fixed electrode having inner and outer surfaces; a substantially transparent dielectric layer applied on said outer surface of said fixed electrode; at least one resilient sheet electrode fixed at one end thereof to the base and extending therefrom adjacent to the fixed electrode; a means for applying a voltage between the fixed electrode and the resilient sheet electrode; and a display placed on or behind said inner surface of the fixed electrode; whereby when there is no voltage between the fixed electrode and the sheet electrode, the display is visible through the substantially transparent fixed electrode and the substantially transparent dielectric layer thereon, whereas upon applying a voltage between the fixed electrode and the sheet electrode, the sheet electrode is attracted to and covers the outer surface of the fixed electrode, thereby concealing the display.
Claim 3
Dependent Claim
28 words
An electrostatic display device as claimed in claim 1, wherein the fixed electrode comprises a substantially transparent material with a substantially transparent electrically conductive material uniformly dispersed therein.
Claim 4
Dependent Claim
29 words
An electrostatic display device as claimed in claim 1, wherein the fixed electrode comprises a substantially transparent glass mold with a substantially transparent electrically conductive powder uniformly dispersed therein.
Claim 5
Dependent Claim
30 words
An electrostatic display device as claimed in claim 1, wherein the fixed electrode comprises a substantially transparent synthetic resin mold with a substantially transparent electrically conductive powder uniformly dispersed therein.
Claim 6
Dependent Claim
16 words
An electrostatic display device as claimed in claim 1, wherein the dielectric layer comprises silicon dioxide.
Claim 7
Dependent Claim
30 words
An electrostatic display device as claimed in claim 1, wherein the resilient sheet electrode comprises a polymer film having a thin layer of a metal deposited on opposite sides thereof.
Claim 8
Dependent Claim
18 words
An electrostatic display device as claimed in claim 6, wherein the polymer film is a polyethylene terephthalate film.
Claim 9
Dependent Claim
14 words
An electrostatic display device as claimed in claim 6, wherein the metal is aluminum.
Claim 10
Dependent Claim
31 words
An electrostatic display device as claimed in claim 1, wherein the sheet electrode is a thin film of a metal having on opposite sides thereof thin layers of a synthetic resin.
Claim 11
Dependent Claim
27 words
An electrostatic display device as claimed in claim 1, wherein the display is a colored layer of paint applied on the inner surface of the fixed electrode.
Claim 12
Dependent Claim
28 words
An electrostatic display device as claimed in claim 1, wherein the display is a reflective layer of a metal deposited on the inner surface of the fixed electrode.
Claim 13
Dependent Claim
25 words
An electrostatic display device as claimed in claim 1, wherein the display is removably placed on or behind the inner surface of the fixed electrode.
Claim 14
Dependent Claim
16 words
An electrostatic display device as claimed in claim 12, wherein the display is a reflective member.
Claim 15
Dependent Claim
16 words
An electrostatic display device as claimed in claim 12, wherein the display is a luminous member.
Claim 16
Dependent Claim
17 words
An electrostatic display device as claimed in claim 12, wherein the display is a diffused reflective member.
Claim 17
Dependent Claim
24 words
An electrostatic display device as claimed in claim 1, wherein the fixed electrode has therein a hollow in which the display is removably placed.
References Cited (Backward Citations)
US3897997A
Cited
US3989357A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |