US3890929A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Xerographic developing apparatus
Assignee: Xerox Corp
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Filing: 1974-05-24
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Granted: 1975-06-24
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Expires: 1994-05-24
Abstract
Abstract An apparatus for developing a latent xerographic image is disclosed. The development device comprises a toner supporting donor member adjacent, and in spaced relationship to, an image retaining member. In addition, there is provided a means to introduce a pulsed electrical field across the gap between the donor and image retaining member whereby the electroscopic particles are made more readily available to the charged image thereby resulting in fine image development.
Inventors
- 👤 Lewis E Walkup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:45
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
An apparatus for developing a latent electrostatic image recorded on an image retaining member comprising: a. a donor member for supporting a uniform layer of electroscopic developing material adjacent the image retaining member, said donor member and image retaining member being spacially disposed as to create a space gap between both members; and b. means to introduce a pulse electRical bias across said gap, said pulse being of a strength and a duration sufficient to enable the deposition of the electroscopic material onto the charged image areas and prevent the development of non-image areas.
Claim 2
Independent Claim
94 words
An apparatus for developing a latent electrostatic image recorded on an image retaining member comprising: a. a donor member for supporting a uniform layer of electroscopic developing material adjacent the image retaining member, said donor member and image retaining member being spacially disposed as to create a space gap between both members; and b. means to introduce a pulse electRical bias across said gap, said pulse being of a strength and a duration sufficient to enable the deposition of the electroscopic material onto the charged image areas and prevent the development of non-image areas.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said pulse has a frequency of from about 10 to 3000 kilocycles/sec.
Claim 4
Dependent Claim
20 words
The apparatus of claim 1 wherein the spacial gap between the donor and the photoreceptor measures up to 7 mils.
Claim 5
Dependent Claim
19 words
The apparatus of claim 1 wherein the voltage range of the pulse bias is up to about +750 volts.
Claim 6
Dependent Claim
17 words
The apparatus of claim 1 wherein the donor member is in the form of a rotatable cylinder.
Claim 7
Dependent Claim
31 words
The apparatus of claim 5 wherein the cylindrical donor comprises an aluminum substrate and an enamel surface layer supporting an etched layer of copper in the form of a grid pattern.
Claim 8
Dependent Claim
15 words
The apparatus of claim 6 wherein the grid contains 120 to 150 lines per inch.
Claim 9
Independent Claim
110 words
An apparatus for developing a latent electrostatic image recorded on an image retaining member comprising: a. a cylindrical donor member being adapted to support a uniform layer of finely divided toner on the surface thereof, said donor being spacially positioned adjacent said image retaining member by means of a small space gap; b. means to apply bias potential across the space gap to effect removal of the toner particles from the donor and onto the charged areas of the photoconductive plate; and c. means to periodically pulse said bias potential to a zero potential whereby toner not in the field of the charged image areas returns to the donor member.
Claim 10
Independent Claim
110 words
An apparatus for developing a latent electrostatic image recorded on an image retaining member comprising: a. a cylindrical donor member being adapted to support a uniform layer of finely divided toner on the surface thereof, said donor being spacially positioned adjacent said image retaining member by means of a small space gap; b. means to apply bias potential across the space gap to effect removal of the toner particles from the donor and onto the charged areas of the photoconductive plate; and c. means to periodically pulse said bias potential to a zero potential whereby toner not in the field of the charged image areas returns to the donor member.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |