US3784294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image density control
Assignee: Xerox Corp
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Filing: 1971-10-04
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Granted: 1974-01-08
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Expires: 1991-10-04
Abstract
Abstract A photoelectrophoretic imaging apparatus comprising two additional electrodes for increasing the density and reducing background level of an image reproduced at high speeds.
Inventors
- 👤 J Wells
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:16
CPC Classifications
G; G03; G03G; G03G17/00; G03G17/04
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
349 words
A photoelectrophoretic imaging apparatus comprising in combination: a. an optically transparent first electrode adapted to support a layer of imaging suspension and adapted to have the surface of said electrode advanced relative to items (b), (c), (e), (f) and (h) recited below; b. means for Introducing a layer of imaging suspension to the surface of said optically transparent first electrode; c. a second electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station, in the direction of advancement of said optically transparent first electrode, after said means for introducing a layer of imaging suspension; d. means to apply a first electrical potential difference across the layer of imaging suspension between said optically transparent first electrode and said second electrode; e. a third imaging electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station, in the direction of advancement of said optically transparent first electrode, after said second electrode; f. a fourth electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station in the direction of advancement of said optically transparent first electrode after said second electrode and before said third imaging electrode and mounted adjacent an imaging contact area established between said optically transparent first electrode and said third imaging electrode; g. means to apply a second potential difference across the layer of imaging suspension between said fourth electrode and said optically transparent first electrode; h. means to expose with actinic electromagnetic radiation of an image to be reproduced, that portion of the layer of imaging suspension at an area of contact of said third imaging electrode and said optically transparent first electrode; and i. means to apply a third potential difference across the layer of imaging suspension, between said third imaging electrode and said optically transparent first electrode during said exposure.
Claim 2
Dependent Claim
349 words
A photoelectrophoretic imaging apparatus comprising in combination: a. an optically transparent first electrode adapted to support a layer of imaging suspension and adapted to have the surface of said electrode advanced relative to items (b), (c), (e), (f) and (h) recited below; b. means for Introducing a layer of imaging suspension to the surface of said optically transparent first electrode; c. a second electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station, in the direction of advancement of said optically transparent first electrode, after said means for introducing a layer of imaging suspension; d. means to apply a first electrical potential difference across the layer of imaging suspension between said optically transparent first electrode and said second electrode; e. a third imaging electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station, in the direction of advancement of said optically transparent first electrode, after said second electrode; f. a fourth electrode mounted in close proximity to said optically transparent first electrode so as to make contact with a free surface of the layer of imaging suspension, at a station in the direction of advancement of said optically transparent first electrode after said second electrode and before said third imaging electrode and mounted adjacent an imaging contact area established between said optically transparent first electrode and said third imaging electrode; g. means to apply a second potential difference across the layer of imaging suspension between said fourth electrode and said optically transparent first electrode; h. means to expose with actinic electromagnetic radiation of an image to be reproduced, that portion of the layer of imaging suspension at an area of contact of said third imaging electrode and said optically transparent first electrode; and i. means to apply a third potential difference across the layer of imaging suspension, between said third imaging electrode and said optically transparent first electrode during said exposure.
Claim 3
Dependent Claim
27 words
Apparatus according to claim 1 wherein said means to apply a third potential difference comprises means to apply a potential difference at least about 3,500 volts D.C.
Claim 4
Dependent Claim
40 words
Apparatus according to claim 1 further comprising means for advancing a receiving member between said optically transparent first electrode and said third imaging electrode at the area of contact of said third imaging electrode and said optically transparent first electrode.
Claim 5
Dependent Claim
38 words
Apparatus according to claim 1 wherein said means to expose is adapted to project an image along the longitudinal axis of said transparent electrode into the nip of said optically transparent first electrode and said third imaging electrode.
Claim 6
Dependent Claim
39 words
Apparatus according to claim 1 wherein said means to apply a first potential difference comprises means to apply a potential difference below the corona threshold for the air gap between the layer of imaging suspension and said second electrode.
Claim 7
Dependent Claim
35 words
Apparatus according to claim 5 wherein said means to apply a first potential difference comprises means to apply a potential difference below about 2,500 volts and of the same polarity as said second potential difference.
Claim 8
Dependent Claim
39 words
Apparatus according to claim 1 wherein said means to apply a second potential difference comprises means to apply a potential difference above the corona threshold for the air gap between the layer of imaging suspension and said fourth electrode.
Claim 9
Dependent Claim
36 words
Apparatus according to claim 7 wherein said means to apply a second potential difference comprises means to apply a potential difference above about 3,500 volts D.C. and of the same polarity as said first potential difference.
Claim 10
Dependent Claim
15 words
Apparatus according to claim 1 wherein each of said electrodes is a rotatably mounted roller.
Claim 11
Dependent Claim
16 words
Apparatus according to claim 9 further comprising means for rotating each of said electrodes in synchronization.
Claim 12
Dependent Claim
34 words
Apparatus according to claim 1 further comprising means for controlling said first potential difference so as to maintAin concentration of pigment in the layer of imaging suspension relatively constant and at the desired level.
Claim 13
Dependent Claim
29 words
Apparatus according to claim 11 wherein said means for controlling comprises a photocell to measure density of the layer of imaging suspension between said second and said fourth electrodes.
Claim 14
Dependent Claim
338 words
A photoelectrophoretic imaging apparatus comprising in combination: a. an optically transparent, flat plate, first electrode adapted to support a layer of imaging suspension; b. means for introducing a layer of imaging suspension to the surface of said optically transparent, flat plate, first electrode; c. a second electrode mounted in close proximity to said first electrode such that said second electrode can make progressively advancing contact with a free surface of a layer of imaging suspension on the surface of said optically transparent, flat plate, first electrode; d. means to apply a first potential difference across the layer of imaging suspension, between said optically transparent, flat plate, first electrode and said second electrode; e. a third, imaging electrode mounted in close proximity to said optically transparent, flat plate, first electrode at a station in the direction of advancement of said second electrode, after said second electrode such that said third, imaging electrode can make progressively advancing contact with a free surface of a layer of imaging suspension on the surface of said optically transparent, flat plate, first electrode; f. a fourth electrode mounted in close proximity to said optically transparent, flat plate, first electrode so as to make surface contact with a free surface of the layer of imaging suspension and at a station between said second elecrode and said third, imaging electrode; g. means to apply a second potential difference across the layer of imaging suspension between said fourth electrode and said optically transparent, flat plate, first electrode; h. means to expose with actinic electromagnetic radiation of an image to be reproduced, that portion of the layer of imaging suspension at an area of contact of said third, imaging electrode and said optically transparent, flat plate, first electrode; i. means to apply a third potential difference across the layer of imaging suspension between said third, imaging electrode and said optically transparent, first electrode during said exposure; and j. means to cause relative movement between said optically transparent, flat plate, first electrode and said second, third and fourth electrodes.
Claim 15
Dependent Claim
338 words
A photoelectrophoretic imaging apparatus comprising in combination: a. an optically transparent, flat plate, first electrode adapted to support a layer of imaging suspension; b. means for introducing a layer of imaging suspension to the surface of said optically transparent, flat plate, first electrode; c. a second electrode mounted in close proximity to said first electrode such that said second electrode can make progressively advancing contact with a free surface of a layer of imaging suspension on the surface of said optically transparent, flat plate, first electrode; d. means to apply a first potential difference across the layer of imaging suspension, between said optically transparent, flat plate, first electrode and said second electrode; e. a third, imaging electrode mounted in close proximity to said optically transparent, flat plate, first electrode at a station in the direction of advancement of said second electrode, after said second electrode such that said third, imaging electrode can make progressively advancing contact with a free surface of a layer of imaging suspension on the surface of said optically transparent, flat plate, first electrode; f. a fourth electrode mounted in close proximity to said optically transparent, flat plate, first electrode so as to make surface contact with a free surface of the layer of imaging suspension and at a station between said second elecrode and said third, imaging electrode; g. means to apply a second potential difference across the layer of imaging suspension between said fourth electrode and said optically transparent, flat plate, first electrode; h. means to expose with actinic electromagnetic radiation of an image to be reproduced, that portion of the layer of imaging suspension at an area of contact of said third, imaging electrode and said optically transparent, flat plate, first electrode; i. means to apply a third potential difference across the layer of imaging suspension between said third, imaging electrode and said optically transparent, first electrode during said exposure; and j. means to cause relative movement between said optically transparent, flat plate, first electrode and said second, third and fourth electrodes.
Claim 16
Dependent Claim
21 words
Apparatus according to claim 13 futher comprising means to disengage said optically transparent, flat plate, first electrode from said remaining electrodes.
Claim 17
Dependent Claim
21 words
Apparatus according to claim 13 wherein said second electrode, said third, imaging electrode and said fourth electrode are rotatably mounted rollers.
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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |