Patent US4228431A successfully refreshed from Google Patents.
US4228431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochromic display device
Assignee: International Business Machines Corp
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Filing: 1977-12-13
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Granted: 1980-10-14
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Expires: 1997-12-13
Abstract
Abstract According to the disclosure, electrochromic display apparatus is provided, comprising, an electrolyte containing an electrochromic material, a plurality of display electrodes in the electrolyte, the display electrodes being connected in at least one group to enable selection of display electrodes, means for selecting at least some display electrodes, means to effect deposition of a visible coating of colored species derived from the electrochromic material onto the selected display electrodes, and means to effect deposition of an invisible coating of the colored species onto all unselected display electrodes, whereby the potentials of selected and unselected display electrodes are equalized.
Inventors
- 👤 Donald J. Barclay
- 👤 Colin L. Bird
- 👤 Michael H. Hallett
- 👤 David H. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:56
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/38; G09G2300/00; G09G2300/08; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/027; G09G2310/06; G09G2310/061; G09G2310/062; G09G2310/063
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
93 words
Electrochromic display apparatus, comprising: an electrolyte containing an electrochromic material, a plurality of display electrodes in said electrolyte, said display electrodes being electrically connected in at least one group to enable selection of display electrodes, means for selecting at least some display electrodes, means to effect deposition of a visible coating of coloured species derived from the electrochromic material onto said selected display electrodes, and means to effect deposition of an invisible coating of the coloured species onto all unselected display electrodes, whereby the potentials of selected and unselected display electrodes are equalised.
Claim 2
Dependent Claim
93 words
Electrochromic display apparatus, comprising: an electrolyte containing an electrochromic material, a plurality of display electrodes in said electrolyte, said display electrodes being electrically connected in at least one group to enable selection of display electrodes, means for selecting at least some display electrodes, means to effect deposition of a visible coating of coloured species derived from the electrochromic material onto said selected display electrodes, and means to effect deposition of an invisible coating of the coloured species onto all unselected display electrodes, whereby the potentials of selected and unselected display electrodes are equalised.
Claim 3
Dependent Claim
64 words
Apparatus as set forth in claim 1, wherein said display electrodes are approximately of equal area, said means to effect deposition of said visible coating effects deposition at a given rate for a given time, and said means to effect deposition of said invisible coating effects deposition at the given rate for a particular time which is a fixed proportion of said given time.
Claim 4
Dependent Claim
114 words
Apparatus as claimed in claim 1 wherein said display electrodes are of approximately equal area, are arranged in a first plurality of rows and in a second plurality of columns, and are each connected to a respective electronic switch having a control electrode responsive to applied potential to control the passage of current through said switch to the related display electrode, a first plurality of row conductors, said control electrodes of the respective row being connected to a respective row conductor, and a second plurality of column conductors, and a plurality of column drive circuitry units, said electronic switches are connected through respective column conductors to respective ones of said column drive circuitry units.
Claim 5
Dependent Claim
106 words
Apparatus as claimed in claim 3, wherein each column drive circuitry unit includes a bistable circuit with a first stable state and a second stable state, a current source, and a transistor switch connected in series with the respective column conductor and the current source, said transistor switch being adapted to be closed for a time period sufficient to deposit a visible coating of coloured species when the bistable circuit is in said first stable state, and said transistor switch being closed for a time period sufficient only to deposit an invisible coating of coloured species when said bistable circuit is in said second stable state.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |